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Document 32017D1442

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Commission Implementing Decision (EU) 2017/1442 of 31 July 2017 establishing best available techniques (BAT) conclusions, under Directive 2010/75/EU of the European Parliament and of the Council, for large combustion plants (notified under document C(2017) 5225) (Text with EEA relevance. )

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17.8.2017   

EN

Official Journal of the European Union

L 212/1


COMMISSION IMPLEMENTING DECISION (EU) 2017/1442

of 31 July 2017

establishing best available techniques (BAT) conclusions, under Directive 2010/75/EU of the European Parliament and of the Council, for large combustion plants

(notified under document C(2017) 5225)

(Text with EEA relevance)

THE EUROPEAN COMMISSION,

Having regard to the Treaty on the Functioning of the European Union,

Having regard to Directive 2010/75/EU of the European Parliament and of the Council of 24 November 2010 on industrial emissions (integrated pollution prevention and control) (1), and in partiular Article 13(5) thereof,

Whereas:

(1)

Best available techniques (BAT) conclusions are the reference for setting permit conditions for installations covered by Chapter II of Directive 2010/75/EU and competent authorities should set emission limit values which ensure that, under normal operating conditions, emissions do not exceed the emission levels associated with the best available techniques as laid down in the BAT conclusions.

(2)

The forum composed of representatives of Member States, the industries concerned and non-governmental organisations promoting environmental protection, established by Commission Decision of 16 May 2011 (2), provided the Commission on 20 October 2016 with its opinion on the proposed content of the BAT reference document for large combustion plants. That opinion is publicly available.

(3)

The BAT conclusions set out in the Annex to this Decision are the key element of that BAT reference document.

(4)

The measures provided for in this Decision are in accordance with the opinion of the Committee established by Article 75(1) of Directive 2010/75/EU,

HAS ADOPTED THIS DECISION:

Article 1

The best available techniques (BAT) conclusions for large combustion plants, as set out in the Annex, are adopted.

Article 2

This Decision is addressed to the Member States.

Done at Brussels, 31 July 2017.

For the Commission

Karmenu VELLA

Member of the Commission


(1)  OJ L 334, 17.12.2010, p. 17.

(2)  OJ C 146, 17.5.2011, p. 3.


ANNEX

BEST AVAILABLE TECHNIQUES (BAT) CONCLUSIONS

SCOPE

These BAT conclusions concern the following activities specified in Annex I to Directive 2010/75/EU:

1.1: Combustion of fuels in installations with a total rated thermal input of 50 MW or more, only when this activity takes place in combustion plants with a total rated thermal input of 50 MW or more.

1.4: Gasification of coal or other fuels in installations with a total rated thermal input of 20 MW or more, only when this activity is directly associated to a combustion plant.

5.2: Disposal or recovery of waste in waste co-incineration plants for non-hazardous waste with a capacity exceeding 3 tonnes per hour or for hazardous waste with a capacity exceeding 10 tonnes per day, only when this activity takes place in combustion plants covered under 1.1 above.

In particular, these BAT conclusions cover upstream and downstream activities directly associated with the aforementioned activities including the emission prevention and control techniques applied.

The fuels considered in these BAT conclusions are any solid, liquid and/or gaseous combustible material including:

solid fuels (e.g. coal, lignite, peat),

biomass (as defined in Article 3(31) of Directive 2010/75/EU),

liquid fuels (e.g. heavy fuel oil and gas oil),

gaseous fuels (e.g. natural gas, hydrogen-containing gas and syngas),

industry-specific fuels (e.g. by-products from the chemical and iron and steel industries),

waste except mixed municipal waste as defined in Article 3(39) and except other waste listed in Article 42(2)(a)(ii) and (iii) of Directive 2010/75/EU.

These BAT conclusions do not address the following:

combustion of fuels in units with a rated thermal input of less than 15 MW,

combustion plants benefitting from the limited life time or district heating derogation as set out in Articles 33 and 35 of Directive 2010/75/EU, until the derogations set in their permits expire, for what concerns the BAT-AELs for the pollutants covered by the derogation, as well as for other pollutants whose emissions would have been reduced by the technical measures obviated by the derogation,

gasification of fuels, when not directly associated to the combustion of the resulting syngas,

gasification of fuels and subsequent combustion of syngas when directly associated to the refining of mineral oil and gas,

the upstream and downstream activities not directly associated to combustion or gasification activities,

combustion in process furnaces or heaters,

combustion in post-combustion plants,

flaring,

combustion in recovery boilers and total reduced sulphur burners within installations for the production of pulp and paper, as this is covered by the BAT conclusions for the production of pulp, paper and board,

combustion of refinery fuels at the refinery site, as this is covered by the BAT conclusions for the refining of mineral oil and gas,

disposal or recovery of waste in:

waste incineration plants (as defined in Article 3(40) of Directive 2010/75/EU),

waste co-incineration plants where more than 40 % of the resulting heat release comes from hazardous waste,

waste co-incineration plants combusting only wastes, except if these wastes are composed at least partially of biomass as defined in Article 3(31)(b) of Directive 2010/75/EU,

as this is covered by the BAT conclusions for waste incineration.

Other BAT conclusions and reference documents that could be relevant for the activities covered by these BAT conclusions are the following:

Common Waste Water and Waste Gas Treatment/Management Systems in the Chemical Sector (CWW)

Chemical BREF series (LVOC, etc.)

Economics and Cross-Media Effects (ECM)

Emissions from Storage (EFS)

Energy Efficiency (ENE)

Industrial Cooling Systems (ICS)

Iron and Steel Production (IS)

Monitoring of Emissions to Air and Water from IED installations (ROM)

Production of Pulp, Paper and Board (PP)

Refining of Mineral Oil and Gas (REF)

Waste Incineration (WI)

Waste Treatment (WT)

DEFINITIONS

For the purposes of these BAT conclusions, the following definitions apply:

Term used

Definition

General terms

Boiler

Any combustion plant with the exception of engines, gas turbines, and process furnaces or heaters

Combined-cycle gas turbine (CCGT)

A CCGT is a combustion plant where two thermodynamic cycles are used (i.e. Brayton and Rankine cycles). In a CCGT, heat from the flue-gas of a gas turbine (operating according to the Brayton cycle to produce electricity) is converted to useful energy in a heat recovery steam generator (HRSG), where it is used to generate steam, which then expands in a steam turbine (operating according to the Rankine cycle to produce additional electricity).

For the purpose of these BAT conclusions, a CCGT includes configurations both with and without supplementary firing of the HRSG

Combustion plant

Any technical apparatus in which fuels are oxidised in order to use the heat thus generated. For the purposes of these BAT conclusions, a combination formed of:

two or more separate combustion plants where the flue-gases are discharged through a common stack, or

separate combustion plants that have been granted a permit for the first time on or after 1 July 1987, or for which the operators have submitted a complete application for a permit on or after that date, which are installed in such a way that, taking technical and economic factors into account, their flue-gases could, in the judgment of the competent authority, be discharged through a common stack

is considered as a single combustion plant.

For calculating the total rated thermal input of such a combination, the capacities of all individual combustion plants concerned, which have a rated thermal input of at least 15 MW, shall be added together

Combustion unit

Individual combustion plant

Continuous measurement

Measurement using an automated measuring system permanently installed on site

Direct discharge

Discharge (to a receiving water body) at the point where the emission leaves the installation without further downstream treatment

Flue-gas desulphurisation (FGD) system

System composed of one or a combination of abatement technique(s) whose purpose is to reduce the level of SOX emitted by a combustion plant

Flue-gas desulphurisation (FGD) system — existing

A flue-gas desulphurisation (FGD) system that is not a new FGD system

Flue-gas desulphurisation (FGD) system — new

Either a flue-gas desulphurisation (FGD) system in a new plant or a FGD system that includes at least one abatement technique introduced or completely replaced in an existing plant following the publication of these BAT conclusions

Gas oil

Any petroleum-derived liquid fuel falling within CN code 2710 19 25 , 2710 19 29 , 2710 19 47 , 2710 19 48 , 2710 20 17 or 2710 20 19 .

Or any petroleum-derived liquid fuel of which less than 65 vol-% (including losses) distils at 250 °C and of which at least 85 vol-% (including losses) distils at 350 °C by the ASTM D86 method

Heavy fuel oil (HFO)

Any petroleum-derived liquid fuel falling within CN code 2710 19 51 to 2710 19 68 , 2710 20 31 , 2710 20 35 , 2710 20 39 .

Or any petroleum-derived liquid fuel, other than gas oil, which, by reason of its distillation limits, falls within the category of heavy oils intended for use as fuel and of which less than 65 vol-% (including losses) distils at 250 °C by the ASTM D86 method. If the distillation cannot be determined by the ASTM D86 method, the petroleum product is also categorised as a heavy fuel oil

Net electrical efficiency (combustion unit and IGCC)

Ratio between the net electrical output (electricity produced on the high-voltage side of the main transformer minus the imported energy — e.g. for auxiliary systems' consumption) and the fuel/feedstock energy input (as the fuel/feedstock lower heating value) at the combustion unit boundary over a given period of time

Net mechanical energy efficiency

Ratio between the mechanical power at load coupling and the thermal power supplied by the fuel

Net total fuel utilisation (combustion unit and IGCC)

Ratio between the net produced energy (electricity, hot water, steam, mechanical energy produced minus the imported electrical and/or thermal energy (e.g. for auxiliary systems' consumption)) and the fuel energy input (as the fuel lower heating value) at the combustion unit boundary over a given period of time

Net total fuel utilisation (gasification unit)

Ratio between the net produced energy (electricity, hot water, steam, mechanical energy produced, and syngas (as the syngas lower heating value) minus the imported electrical and/or thermal energy (e.g. for auxiliary systems' consumption)) and the fuel/feedstock energy input (as the fuel/feedstock lower heating value) at the gasification unit boundary over a given period of time

Operated hours

The time, expressed in hours, during which a combustion plant, in whole or in part, is operated and is discharging emissions to air, excluding start-up and shutdown periods

Periodic measurement

Determination of a measurand (a particular quantity subject to measurement) at specified time intervals

Plant — existing

A combustion plant that is not a new plant

Plant — new

A combustion plant first permitted at the installation following the publication of these BAT conclusions or a complete replacement of a combustion plant on the existing foundations following the publication of these BAT conclusions

Post-combustion plant

System designed to purify the flue-gases by combustion which is not operated as an independent combustion plant, such as a thermal oxidiser (i.e. tail gas incinerator), used for the removal of the pollutant(s) (e.g. VOC) content from the flue-gas with or without the recovery of the heat generated therein. Staged combustion techniques, where each combustion stage is confined within a separate chamber, which may have distinct combustion process characteristics (e.g. fuel to air ratio, temperature profile), are considered integrated in the combustion process and are not considered post-combustion plants. Similarly, when gases generated in a process heater/furnace or in another combustion process are subsequently oxidised in a distinct combustion plant to recover their energetic value (with or without the use of auxiliary fuel) to produce electricity, steam, hot water/oil or mechanical energy, the latter plant is not considered a post-combustion plant

Predictive emissions monitoring system (PEMS)

System used to determine the emissions concentration of a pollutant from an emission source on a continuous basis, based on its relationship with a number of characteristic continuously monitored process parameters (e.g. the fuel gas consumption, the air to fuel ratio) and fuel or feed quality data (e.g. the sulphur content)

Process fuels from the chemical industry

Gaseous and/or liquid by-products generated by the (petro-)chemical industry and used as non-commercial fuels in combustion plants

Process furnaces or heaters

Process furnaces or heaters are:

combustion plants whose flue-gases are used for the thermal treatment of objects or feed material through a direct contact heating mechanism (e.g. cement and lime kiln, glass furnace, asphalt kiln, drying process, reactor used in the (petro-)chemical industry, ferrous metal processing furnaces), or

combustion plants whose radiant and/or conductive heat is transferred to objects or feed material through a solid wall without using an intermediary heat transfer fluid (e.g. coke battery furnace, cowper, furnace or reactor heating a process stream used in the (petro-)chemical industry such as a steam cracker furnace, process heater used for the regasification of liquefied natural gas (LNG) in LNG terminals).

As a consequence of the application of good energy recovery practices, process heaters/furnaces may have an associated steam/electricity generation system. This is considered to be an integral design feature of the process heater/furnace that cannot be considered in isolation

Refinery fuels

Solid, liquid or gaseous combustible material from the distillation and conversion steps of the refining of crude oil. Examples are refinery fuel gas (RFG), syngas, refinery oils, and pet coke

Residues

Substances or objects generated by the activities covered by the scope of this document, as waste or by-products

Start-up and shut-down period

The time period of plant operation as determined pursuant to the provisions of Commission Implementing Decision 2012/249/EU (*1)

Unit — existing

A combustion unit that is not a new unit

Unit- new

A combustion unit first permitted at the combustion plant following the publication of these BAT conclusions or a complete replacement of a combustion unit on the existing foundations of the combustion plant following the publication of these BAT conclusions

Valid (hourly average)

An hourly average is considered valid when there is no maintenance or malfunction of the automated measuring system


Term used

Definition

Pollutants/parameters

As

The sum of arsenic and its compounds, expressed as As

C3

Hydrocarbons having a carbon number equal to three

C4+

Hydrocarbons having a carbon number of four or greater

Cd

The sum of cadmium and its compounds, expressed as Cd

Cd+Tl

The sum of cadmium, thallium and their compounds, expressed as Cd+Tl

CH4

Methane

CO

Carbon monoxide

COD

Chemical oxygen demand. Amount of oxygen needed for the total oxidation of the organic matter to carbon dioxide

COS

Carbonyl sulphide

Cr

The sum of chromium and its compounds, expressed as Cr

Cu

The sum of copper and its compounds, expressed as Cu

Dust

Total particulate matter (in air)

Fluoride

Dissolved fluoride, expressed as F

H2S

Hydrogen sulphide

HCl

All inorganic gaseous chlorine compounds, expressed as HCl

HCN

Hydrogen cyanide

HF

All inorganic gaseous fluorine compounds, expressed as HF

Hg

The sum of mercury and its compounds, expressed as Hg

N2O

Dinitrogen monoxide (nitrous oxide)

NH3

Ammonia

Ni

The sum of nickel and its compounds, expressed as Ni

NOX

The sum of nitrogen monoxide (NO) and nitrogen dioxide (NO2), expressed as NO2

Pb

The sum of lead and its compounds, expressed as Pb

PCDD/F

Polychlorinated dibenzo-p-dioxins and -furans

RCG

Raw concentration in the flue-gas. Concentration of SO2 in the raw flue-gas as a yearly average (under the standard conditions given under General considerations) at the inlet of the SOX abatement system, expressed at a reference oxygen content of 6 vol-% O2

Sb + As + Pb + Cr + Co + Cu + Mn + Ni + V

The sum of antimony, arsenic, lead, chromium, cobalt, copper, manganese, nickel, vanadium and their compounds, expressed as Sb + As + Pb + Cr + Co + Cu + Mn + Ni + V

SO2

Sulphur dioxide

SO3

Sulphur trioxide

SOX

The sum of sulphur dioxide (SO2) and sulphur trioxide (SO3), expressed as SO2

Sulphate

Dissolved sulphate, expressed as SO4 2–

Sulphide, easily released

The sum of dissolved sulphide and of those undissolved sulphides that are easily released upon acidification, expressed as S2–

Sulphite

Dissolved sulphite, expressed as SO3 2–

TOC

Total organic carbon, expressed as C (in water)

TSS

Total suspended solids. Mass concentration of all suspended solids (in water), measured via filtration through glass fibre filters and gravimetry

TVOC

Total volatile organic carbon, expressed as C (in air)

Zn

The sum of zinc and its compounds, expressed as Zn

ACRONYMS

For the purposes of these BAT conclusions, the following acronyms apply:

Acronym

Definition

ASU

Air supply unit

CCGT

Combined-cycle gas turbine, with or without supplementary firing

CFB

Circulating fluidised bed

CHP

Combined heat and power

COG

Coke oven gas

COS

Carbonyl sulphide

DLN

Dry low-NOX burners

DSI

Duct sorbent injection

ESP

Electrostatic precipitator

FBC

Fluidised bed combustion

FGD

Flue-gas desulphurisation

HFO

Heavy fuel oil

HRSG

Heat recovery steam generator

IGCC

Integrated gasification combined cycle

LHV

Lower heating value

LNB

Low-NOX burners

LNG

Liquefied natural gas

OCGT

Open-cycle gas turbine

OTNOC

Other than normal operating conditions

PC

Pulverised combustion

PEMS

Predictive emissions monitoring system

SCR

Selective catalytic reduction

SDA

Spray dry absorber

SNCR

Selective non-catalytic reduction

GENERAL CONSIDERATIONS

Best Available Techniques

The techniques listed and described in these BAT conclusions are neither prescriptive nor exhaustive. Other techniques may be used that ensure at least an equivalent level of environmental protection.

Unless otherwise stated, these BAT conclusions are generally applicable.

Emission levels associated with the best available techniques (BAT-AELs)

Where emission levels associated with the best available techniques (BAT-AELs) are given for different averaging periods, all of those BAT-AELs have to be complied with.

The BAT-AELs set out in these BAT conclusions may not apply to liquid-fuel-fired and gas-fired turbines and engines for emergency use operated less than 500 h/yr, when such emergency use is not compatible with meeting the BAT-AELs.

BAT-AELs for emissions to air

Emission levels associated with the best available techniques (BAT-AELs) for emissions to air given in these BAT conclusions refer to concentrations, expressed as mass of emitted substance per volume of flue-gas under the following standard conditions: dry gas at a temperature of 273,15 K, and a pressure of 101,3 kPa, and expressed in the units mg/Nm3, μg/Nm3 or ng I-TEQ/Nm3.

The monitoring associated with the BAT-AELs for emissions to air is given in BAT 4

Reference conditions for oxygen used to express BAT-AELs in this document are shown in the table given below.

Activity

Reference oxygen level (OR)

Combustion of solid fuels

6 vol-%

Combustion of solid fuels in combination with liquid and/or gaseous fuels

Waste co-incineration

Combustion of liquid and/or gaseous fuels when not taking place in a gas turbine or an engine

3 vol-%

Combustion of liquid and/or gaseous fuels when taking place in a gas turbine or an engine

15 vol-%

Combustion in IGCC plants

The equation for calculating the emission concentration at the reference oxygen level is:

Formula

Where:

ER

:

emission concentration at the reference oxygen level OR;

OR

:

reference oxygen level in vol- %;

EM

:

measured emission concentration;

OM

:

measured oxygen level in vol- %.

For averaging periods, the following definitions apply:

Averaging period

Definition

Daily average

Average over a period of 24 hours of valid hourly averages obtained by continuous measurements

Yearly average

Average over a period of one year of valid hourly averages obtained by continuous measurements

Average over the sampling period

Average value of three consecutive measurements of at least 30 minutes each (1)

Average of samples obtained during one year

Average of the values obtained during one year of the periodic measurements taken with the monitoring frequency set for each parameter

BAT-AELs for emissions to water

Emission levels associated with the best available techniques (BAT-AELs) for emissions to water given in these BAT conclusions refer to concentrations, expressed as mass of emitted substance per volume of water, and expressed in μg/l, mg/l, or g/l. The BAT-AELs refer to daily averages, i.e. 24-hour flow-proportional composite samples. Time-proportional composite samples can be used provided that sufficient flow stability can be demonstrated.

The monitoring associated with BAT-AELs for emissions to water is given in BAT 5

Energy efficiency levels associated with the best available techniques (BAT-AEELs)

An energy efficiency level associated with the best available techniques (BAT-AEEL) refers to the ratio between the combustion unit's net energy output(s) and the combustion unit's fuel/feedstock energy input at actual unit design. The net energy output(s) is determined at the combustion, gasification, or IGCC unit boundaries, including auxiliary systems (e.g. flue-gas treatment systems), and for the unit operated at full load.

In the case of combined heat and power (CHP) plants:

the net total fuel utilisation BAT-AEEL refers to the combustion unit operated at full load and tuned to maximise primarily the heat supply and secondarily the remaining power that can be generated,

the net electrical efficiency BAT-AEEL refers to the combustion unit generating only electricity at full load.

BAT-AEELs are expressed as a percentage. The fuel/feedstock energy input is expressed as lower heating value (LHV).

The monitoring associated with BAT-AEELs is given in BAT 2

Categorisation of combustion plants/units according to their total rated thermal input

For the purposes of these BAT conclusions, when a range of values for the total rated thermal input is indicated, this is to be read as ‘equal to or greater than the lower end of the range and lower than the upper end of the range’. For example, the plant category 100–300 MWth is to be read as: combustion plants with a total rated thermal input equal to or greater than 100 MW and lower than 300 MW.

When a part of a combustion plant discharging flue-gases through one or more separate ducts within a common stack is operated less than 1 500 h/yr, that part of the plant may be considered separately for the purpose of these BAT conclusions. For all parts of the plant, the BAT-AELs apply in relation to the total rated thermal input of the plant. In such cases, the emissions through each of those ducts are monitored separately.

1.   GENERAL BAT CONCLUSIONS

The fuel-specific BAT conclusions included in Sections 2 to 7 apply in addition to the general BAT conclusions in this section.

1.1.   Environmental management systems

BAT 1.

In order to improve the overall environmental performance, BAT is to implement and adhere to an environmental management system (EMS) that incorporates all of the following features:

(i)

commitment of the management, including senior management;

(ii)

definition, by the management, of an environmental policy that includes the continuous improvement of the environmental performance of the installation;

(iii)

planning and establishing the necessary procedures, objectives and targets, in conjunction with financial planning and investment;

(iv)

implementation of procedures paying particular attention to:

(a)

structure and responsibility

(b)

recruitment, training, awareness and competence

(c)

communication

(d)

employee involvement

(e)

documentation

(f)

effective process control

(g)

planned regular maintenance programmes

(h)

emergency preparedness and response

(i)

safeguarding compliance with environmental legislation;

(v)

checking performance and taking corrective action, paying particular attention to:

(a)

monitoring and measurement (see also the JRC Reference Report on Monitoring of emissions to air and water from IED-installations — ROM)

(b)

corrective and preventive action

(c)

maintenance of records

(d)

independent (where practicable) internal and external auditing in order to determine whether or not the EMS conforms to planned arrangements and has been properly implemented and maintained;

(vi)

review, by senior management, of the EMS and its continuing suitability, adequacy and effectiveness;

(vii)

following the development of cleaner technologies;

(viii)

consideration for the environmental impacts from the eventual decommissioning of the installation at the stage of designing a new plant, and throughout its operating life including;

(a)

avoiding underground structures

(b)

incorporating features that facilitate dismantling

(c)

choosing surface finishes that are easily decontaminated

(d)

using an equipment configuration that minimises trapped chemicals and facilitates drainage or cleaning

(e)

designing flexible, self-contained equipment that enables phased closure

(f)

using biodegradable and recyclable materials where possible;

(ix)

application of sectoral benchmarking on a regular basis.

Specifically for this sector, it is also important to consider the following features of the EMS, described where appropriate in the relevant BAT:

(x)

quality assurance/quality control programmes to ensure that the characteristics of all fuels are fully determined and controlled (see BAT 9);

(xi)

a management plan in order to reduce emissions to air and/or to water during other than normal operating conditions, including start-up and shutdown periods (see BAT 10 and BAT 11);

(xii)

a waste management plan to ensure that waste is avoided, prepared for reuse, recycled or otherwise recovered, including the use of techniques given in BAT 16;

(xiii)

a systematic method to identify and deal with potential uncontrolled and/or unplanned emissions to the environment, in particular:

(a)

emissions to soil and groundwater from the handling and storage of fuels, additives, by-products and wastes

(b)

emissions associated with self-heating and/or self-ignition of fuel in the storage and handling activities;

(xiv)

a dust management plan to prevent or, where that is not practicable, to reduce diffuse emissions from loading, unloading, storage and/or handling of fuels, residues and additives;

(xv)

a noise management plan where a noise nuisance at sensitive receptors is expected or sustained, including;

(a)

a protocol for conducting noise monitoring at the plant boundary

(b)

a noise reduction programme

(c)

a protocol for response to noise incidents containing appropriate actions and timelines

(d)

a review of historic noise incidents, corrective actions and dissemination of noise incident knowledge to the affected parties;

(xvi)

for the combustion, gasification or co-incineration of malodourous substances, an odour management plan including:

(a)

a protocol for conducting odour monitoring

(b)

where necessary, an odour elimination programme to identify and eliminate or reduce the odour emissions

(c)

a protocol to record odour incidents and the appropriate actions and timelines

(d)

a review of historic odour incidents, corrective actions and the dissemination of odour incident knowledge to the affected parties.

Where an assessment shows that any of the elements listed under items x to xvi are not necessary, a record is made of the decision, including the reasons.

Applicability

The scope (e.g. level of detail) and nature of the EMS (e.g. standardised or non-standardised) is generally related to the nature, scale and complexity of the installation, and the range of environmental impacts it may have.

1.2.   Monitoring

BAT 2.

BAT is to determine the net electrical efficiency and/or the net total fuel utilisation and/or the net mechanical energy efficiency of the gasification, IGCC and/or combustion units by carrying out a performance test at full load (2), according to EN standards, after the commissioning of the unit and after each modification that could significantly affect the net electrical efficiency and/or the net total fuel utilisation and/or the net mechanical energy efficiency of the unit. If EN standards are not available, BAT is to use ISO, national or other international standards that ensure the provision of data of an equivalent scientific quality.

BAT 3.

BAT is to monitor key process parameters relevant for emissions to air and water including those given below.

Stream

Parameter(s)

Monitoring

Flue-gas

Flow

Periodic or continuous determination

Oxygen content, temperature, and pressure

Periodic or continuous measurement

Water vapour content (3)

Waste water from flue-gas treatment

Flow, pH, and temperature

Continuous measurement

BAT 4.

BAT is to monitor emissions to air with at least the frequency given below and in accordance with EN standards. If EN standards are not available, BAT is to use ISO, national or other international standards that ensure the provision of data of an equivalent scientific quality.

Substance/Parameter

Fuel/Process/Type of combustion plant

Combustion plant total rated thermal input

Standard(s) (4)

Minimum monitoring frequency (5)

Monitoring associated with

NH3

When SCR and/or SNCR is used

All sizes

Generic EN standards

Continuous (6)  (7)

BAT 7

NOX

Coal and/or lignite including waste co-incineration

Solid biomass and/or peat including waste co-incineration

HFO- and/or gas-oil-fired boilers and engines

Gas-oil-fired gas turbines

Natural-gas-fired boilers, engines, and turbines

Iron and steel process gases

Process fuels from the chemical industry

IGCC plants

All sizes

Generic EN standards

Continuous (6)  (8)

BAT 20

BAT 24

BAT 28

BAT 32

BAT 37

BAT 41

BAT 42

BAT 43

BAT 47

BAT 48

BAT 56

BAT 64

BAT 65

BAT 73

Combustion plants on offshore platforms

All sizes

EN 14792

Once every year (9)

BAT 53

N2O

Coal and/or lignite in circulating fluidised bed boilers

Solid biomass and/or peat in circulating fluidised bed boilers

All sizes

EN 21258

Once every year (10)

BAT 20

BAT 24

CO

Coal and/or lignite including waste co-incineration

Solid biomass and/or peat including waste co-incineration

HFO- and/or gas-oil-fired boilers and engines

Gas-oil-fired gas turbines

Natural-gas-fired boilers, engines, and turbines

Iron and steel process gases

Process fuels from the chemical industry

IGCC plants

All sizes

Generic EN standards

Continuous (6)  (8)

BAT 20

BAT 24

BAT 28

BAT 33

BAT 38

BAT 44

BAT 49

BAT 56

BAT 64

BAT 65

BAT 73

Combustion plants on offshore platforms

All sizes

EN 15058

Once every year (9)

BAT 54

SO2

Coal and/or lignite including waste co-incineration

Solid biomass and/or peat including waste co-incineration

HFO- and/or gas-oil-fired boilers

HFO- and/or gas-oil-fired engines

Gas-oil-fired gas turbines

Iron and steel process gases

Process fuels from the chemical industry in boilers

IGCC plants

All sizes

Generic EN standards and EN 14791

Continuous (6)  (11)  (12)

BAT 21

BAT 25

BAT 29

BAT 34

BAT 39

BAT 50

BAT 57

BAT 66

BAT 67

BAT 74

SO3

When SCR is used

All sizes

No EN standard available

Once every year

Gaseous chlorides, expressed as HCl

Coal and/or lignite

Process fuels from the chemical industry in boilers

All sizes

EN 1911

Once every three months (6)  (13)  (14)

BAT 21

BAT 57

Solid biomass and/or peat

All sizes

Generic EN standards

Continuous (15)  (16)

BAT 25

Waste co-incineration

All sizes

Generic EN standards

Continuous (6)  (16)

BAT 66

BAT 67

HF

Coal and/or lignite

Process fuels from the chemical industry in boilers

All sizes

No EN standard available

Once every three months (6)  (13)  (14)

BAT 21

BAT 57

Solid biomass and/or peat

All sizes

No EN standard available

Once every year

BAT 25

Waste co-incineration

All sizes

Generic EN standards

Continuous (6)  (16)

BAT 66

BAT 67

Dust

Coal and/or lignite

Solid biomass and/or peat

HFO- and/or gas-oil-fired boilers

Iron and steel process gases

Process fuels from the chemical industry in boilers

IGCC plants

HFO- and/or gas-oil-fired engines

Gas-oil-fired gas turbines

All sizes

Generic EN standards and EN 13284-1 and EN 13284-2

Continuous (6)  (17)

BAT 22

BAT 26

BAT 30

BAT 35

BAT 39

BAT 51

BAT 58

BAT 75

Waste co-incineration

All sizes

Generic EN standards and EN 13284-2

Continuous

BAT 68

BAT 69

Metals and metalloids except mercury (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sb, Se, Tl, V, Zn)

Coal and/or lignite

Solid biomass and/or peat

HFO- and/or gas-oil-fired boilers and engines

All sizes

EN 14385

Once every year (18)

BAT 22

BAT 26

BAT 30

Waste co-incineration

< 300 MWth

EN 14385

Once every six months (13)

BAT 68

BAT 69

≥ 300 MWth

EN 14385

Once every three months (19)  (13)

IGCC plants

≥ 100 MWth

EN 14385

Once every year (18)

BAT 75

Hg

Coal and/or lignite including waste co-incineration

< 300 MWth

EN 13211

Once every three months (13)  (20)

BAT 23

≥ 300 MWth

Generic EN standards and EN 14884

Continuous (16)  (21)

Solid biomass and/or peat

All sizes

EN 13211

Once every year (22)

BAT 27

Waste co-incineration with solid biomass and/or peat

All sizes

EN 13211

Once every three months (13)

BAT 70

IGCC plants

≥ 100 MWth

EN 13211

Once every year (23)

BAT 75

TVOC

HFO- and/or gas-oil-fired engines

Process fuels from the chemical industry in boilers

All sizes

EN 12619

Once every six months (13)

BAT 33

BAT 59

Waste co-incineration with coal, lignite, solid biomass and/or peat

All sizes

Generic EN standards

Continuous

BAT 71

Formaldehyde

Natural-gas in spark-ignited lean-burn gas and dual fuel engines

All sizes

No EN standard available

Once every year

BAT 45

CH4

Natural-gas-fired engines

All sizes

EN ISO 25139

Once every year (24)

BAT 45

PCDD/F

Process fuels from the chemical industry in boilers

Waste co-incineration

All sizes

EN 1948-1, EN 1948-2, EN 1948-3

Once every six months (13)  (25)

BAT 59

BAT 71

BAT 5.

BAT is to monitor emissions to water from flue-gas treatment with at least the frequency given below and in accordance with EN standards. If EN standards are not available, BAT is to use ISO, national or other international standards that ensure the provision of data of an equivalent scientific quality.

Substance/Parameter

Standard(s)

Minimum monitoring frequency

Monitoring associated with

Total organic carbon (TOC) (26)

EN 1484

Once every month

BAT 15

Chemical oxygen demand (COD) (26)

No EN standard available

Total suspended solids (TSS)

EN 872

Fluoride (F)

EN ISO 10304-1

Sulphate (SO4 2–)

EN ISO 10304-1

Sulphide, easily released (S2–)

No EN standard available

Sulphite (SO3 2–)

EN ISO 10304-3

Metals and metalloids

As

Various EN standards available (e.g. EN ISO 11885 or EN ISO 17294-2)

Cd

Cr

Cu

Ni

Pb

Zn

Hg

Various EN standards available (e.g. EN ISO 12846 or EN ISO 17852)

Chloride (Cl)

Various EN standards available (e.g. EN ISO 10304-1 or EN ISO 15682)

Total nitrogen

EN 12260

1.3.   General environmental and combustion performance

BAT 6.

In order to improve the general environmental performance of combustion plants and to reduce emissions to air of CO and unburnt substances, BAT is to ensure optimised combustion and to use an appropriate combination of the techniques given below.

Technique

Description

Applicability

a.

Fuel blending and mixing

Ensure stable combustion conditions and/or reduce the emission of pollutants by mixing different qualities of the same fuel type

Generally applicable

b.

Maintenance of the combustion system

Regular planned maintenance according to suppliers' recommendations

c.

Advanced control system

See description in Section 8.1

The applicability to old combustion plants may be constrained by the need to retrofit the combustion system and/or control command system

d.

Good design of the combustion equipment

Good design of furnace, combustion chambers, burners and associated devices

Generally applicable to new combustion plants

e.

Fuel choice

Select or switch totally or partially to another fuel(s) with a better environmental profile (e.g. with low sulphur and/or mercury content) amongst the available fuels, including in start-up situations or when back-up fuels are used

Applicable within the constraints associated with the availability of suitable types of fuel with a better environmental profile as a whole, which may be impacted by the energy policy of the Member State, or by the integrated site's fuel balance in the case of combustion of industrial process fuels.

For existing combustion plants, the type of fuel chosen may be limited by the configuration and the design of the plant

BAT 7.

In order to reduce emissions of ammonia to air from the use of selective catalytic reduction (SCR) and/or selective non-catalytic reduction (SNCR) for the abatement of NOX emissions, BAT is to optimise the design and/or operation of SCR and/or SNCR (e.g. optimised reagent to NOX ratio, homogeneous reagent distribution and optimum size of the reagent drops).

BAT-associated emission levels

The BAT-associated emission level (BAT-AEL) for emissions of NH3 to air from the use of SCR and/or SNCR is < 3–10 mg/Nm3 as a yearly average or average over the sampling period. The lower end of the range can be achieved when using SCR and the upper end of the range can be achieved when using SNCR without wet abatement techniques. In the case of plants combusting biomass and operating at variable loads as well as in the case of engines combusting HFO and/or gas oil, the higher end of the BAT-AEL range is 15 mg/Nm3.

BAT 8.

In order to prevent or reduce emissions to air during normal operating conditions, BAT is to ensure, by appropriate design, operation and maintenance, that the emission abatement systems are used at optimal capacity and availability.

BAT 9.

In order to improve the general environmental performance of combustion and/or gasification plants and to reduce emissions to air, BAT is to include the following elements in the quality assurance/quality control programmes for all the fuels used, as part of the environmental management system (see BAT 1):

(i)

Initial full characterisation of the fuel used including at least the parameters listed below and in accordance with EN standards. ISO, national or other international standards may be used provided they ensure the provision of data of an equivalent scientific quality;

(ii)

Regular testing of the fuel quality to check that it is consistent with the initial characterisation and according to the plant design specifications. The frequency of testing and the parameters chosen from the table below are based on the variability of the fuel and an assessment of the relevance of pollutant releases (e.g. concentration in fuel, flue-gas treatment employed);

(iii)

Subsequent adjustment of the plant settings as and when needed and practicable (e.g. integration of the fuel characterisation and control in the advanced control system (see description in Section 8.1)).

Description

Initial characterisation and regular testing of the fuel can be performed by the operator and/or the fuel supplier. If performed by the supplier, the full results are provided to the operator in the form of a product (fuel) supplier specification and/or guarantee.

Fuel(s)

Substances/Parameters subject to characterisation

Biomass/peat

LHV

moisture

Ash

C, Cl, F, N, S, K, Na

Metals and metalloids (As, Cd, Cr, Cu, Hg, Pb, Zn)

Coal/lignite

LHV

Moisture

Volatiles, ash, fixed carbon, C, H, N, O, S

Br, Cl, F

Metals and metalloids (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Tl, V, Zn)

HFO

Ash

C, S, N, Ni, V

Gas oil

Ash

N, C, S

Natural gas

LHV

CH4, C2H6, C3, C4+, CO2, N2, Wobbe index

Process fuels from the chemical industry (27)

Br, C, Cl, F, H, N, O, S

Metals and metalloids (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Tl, V, Zn)

Iron and steel process gases

LHV, CH4 (for COG), CXHY (for COG), CO2, H2, N2, total sulphur, dust, Wobbe index

Waste (28)

LHV

Moisture

Volatiles, ash, Br, C, Cl, F, H, N, O, S

Metals and metalloids (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Tl, V, Zn)

BAT 10.

In order to reduce emissions to air and/or to water during other than normal operating conditions (OTNOC), BAT is to set up and implement a management plan as part of the environmental management system (see BAT 1), commensurate with the relevance of potential pollutant releases, that includes the following elements:

appropriate design of the systems considered relevant in causing OTNOC that may have an impact on emissions to air, water and/or soil (e.g. low-load design concepts for reducing the minimum start-up and shutdown loads for stable generation in gas turbines),

set-up and implementation of a specific preventive maintenance plan for these relevant systems,

review and recording of emissions caused by OTNOC and associated circumstances and implementation of corrective actions if necessary,

periodic assessment of the overall emissions during OTNOC (e.g. frequency of events, duration, emissions quantification/estimation) and implementation of corrective actions if necessary.

BAT 11.

BAT is to appropriately monitor emissions to air and/or to water during OTNOC.

Description

The monitoring can be carried out by direct measurement of emissions or by monitoring of surrogate parameters if this proves to be of equal or better scientific quality than the direct measurement of emissions. Emissions during start-up and shutdown (SU/SD) may be assessed based on a detailed emission measurement carried out for a typical SU/SD procedure at least once every year, and using the results of this measurement to estimate the emissions for each and every SU/SD throughout the year.

1.4.   Energy efficiency

BAT 12.

In order to increase the energy efficiency of combustion, gasification and/or IGCC units operated ≥ 1 500 h/yr, BAT is to use an appropriate combination of the techniques given below.

Technique

Description

Applicability

a.

Combustion optimisation

See description in Section 8.2.

Optimising the combustion minimises the content of unburnt substances in the flue-gases and in solid combustion residues

Generally applicable

b.

Optimisation of the working medium conditions

Operate at the highest possible pressure and temperature of the working medium gas or steam, within the constraints associated with, for example, the control of NOX emissions or the characteristics of energy demanded

c.

Optimisation of the steam cycle

Operate with lower turbine exhaust pressure by utilisation of the lowest possible temperature of the condenser cooling water, within the design conditions

d.

Minimisation of energy consumption

Minimising the internal energy consumption (e.g. greater efficiency of the feed-water pump)

e.

Preheating of combustion air

Reuse of part of the heat recovered from the combustion flue-gas to preheat the air used in combustion

Generally applicable within the constraints related to the need to control NOX emissions

f.

Fuel preheating

Preheating of fuel using recovered heat

Generally applicable within the constraints associated with the boiler design and the need to control NOX emissions

g.

Advanced control system

See description in Section 8.2.

Computerised control of the main combustion parameters enables the combustion efficiency to be improved

Generally applicable to new units. The applicability to old units may be constrained by the need to retrofit the combustion system and/or control command system

h.

Feed-water preheating using recovered heat

Preheat water coming out of the steam condenser with recovered heat, before reusing it in the boiler

Only applicable to steam circuits and not to hot boilers.

Applicability to existing units may be limited due to constraints associated with the plant configuration and the amount of recoverable heat

i.

Heat recovery by cogeneration (CHP)

Recovery of heat (mainly from the steam system) for producing hot water/steam to be used in industrial processes/activities or in a public network for district heating. Additional heat recovery is possible from:

flue-gas

grate cooling

circulating fluidised bed

Applicable within the constraints associated with the local heat and power demand.

The applicability may be limited in the case of gas compressors with an unpredictable operational heat profile

j.

CHP readiness

See description in Section 8.2.

Only applicable to new units where there is a realistic potential for the future use of heat in the vicinity of the unit

k.

Flue-gas condenser

See description in Section 8.2.

Generally applicable to CHP units provided there is enough demand for low-temperature heat

l.

Heat accumulation

Heat accumulation storage in CHP mode

Only applicable to CHP plants.

The applicability may be limited in the case of low heat load demand

m.

Wet stack

See description in Section 8.2.

Generally applicable to new and existing units fitted with wet FGD

n.

Cooling tower discharge

The release of emissions to air through a cooling tower and not via a dedicated stack

Only applicable to units fitted with wet FGD where reheating of the flue-gas is necessary before release, and where the unit cooling system is a cooling tower

o.

Fuel pre-drying

The reduction of fuel moisture content before combustion to improve combustion conditions

Applicable to the combustion of biomass and/or peat within the constraints associated with spontaneous combustion risks (e.g. the moisture content of peat is kept above 40 % throughout the delivery chain).

The retrofit of existing plants may be restricted by the extra calorific value that can be obtained from the drying operation and by the limited retrofit possibilities offered by some boiler designs or plant configurations

p.

Minimisation of heat losses

Minimising residual heat losses, e.g. those that occur via the slag or those that can be reduced by insulating radiating sources

Only applicable to solid-fuel-fired combustion units and to gasification/IGCC units

q.

Advanced materials

Use of advanced materials proven to be capable of withstanding high operating temperatures and pressures and thus to achieve increased steam/combustion process efficiencies

Only applicable to new plants

r.

Steam turbine upgrades

This includes techniques such as increasing the temperature and pressure of medium-pressure steam, addition of a low-pressure turbine, and modifications to the geometry of the turbine rotor blades

The applicability may be restricted by demand, steam conditions and/or limited plant lifetime

s.

Supercritical and ultra-supercritical steam conditions

Use of a steam circuit, including steam reheating systems, in which steam can reach pressures above 220,6 bar and temperatures above 374 °C in the case of supercritical conditions, and above 250 – 300 bar and temperatures above 580 – 600 °C in the case of ultra-supercritical conditions

Only applicable to new units of ≥ 600 MWth operated > 4 000  h/yr.

Not applicable when the purpose of the unit is to produce low steam temperatures and/or pressures in process industries.

Not applicable to gas turbines and engines generating steam in CHP mode.

For units combusting biomass, the applicability may be constrained by high-temperature corrosion in the case of certain biomasses

1.5.   Water usage and emissions to water

BAT 13.

In order to reduce water usage and the volume of contaminated waste water discharged, BAT is to use one or both of the techniques given below.

Technique

Description

Applicability

a.

Water recycling

Residual aqueous streams, including run-off water, from the plant are reused for other purposes. The degree of recycling is limited by the quality requirements of the recipient water stream and the water balance of the plant

Not applicable to waste water from cooling systems when water treatment chemicals and/or high concentrations of salts from seawater are present

b.

Dry bottom ash handling

Dry, hot bottom ash falls from the furnace onto a mechanical conveyor system and is cooled down by ambient air. No water is used in the process.

Only applicable to plants combusting solid fuels.

There may be technical restrictions that prevent retrofitting to existing combustion plants

BAT 14.

In order to prevent the contamination of uncontaminated waste water and to reduce emissions to water, BAT is to segregate waste water streams and to treat them separately, depending on the pollutant content.

Description

Waste water streams that are typically segregated and treated include surface run-off water, cooling water, and waste water from flue-gas treatment.

Applicability

The applicability may be restricted in the case of existing plants due to the configuration of the drainage systems.

BAT 15.

In order to reduce emissions to water from flue-gas treatment, BAT is to use an appropriate combination of the techniques given below, and to use secondary techniques as close as possible to the source in order to avoid dilution.

Technique

Typical pollutants prevented/abated

Applicability

Primary techniques

a.

Optimised combustion (see BAT 6) and flue-gas treatment systems (e.g. SCR/SNCR, see BAT 7)

Organic compounds, ammonia (NH3)

Generally applicable

Secondary techniques (29)

b.

Adsorption on activated carbon

Organic compounds, mercury (Hg)

Generally applicable

c.

Aerobic biological treatment

Biodegradable organic compounds, ammonium (NH4 +)

Generally applicable for the treatment of organic compounds. Aerobic biological treatment of ammonium (NH4 +) may not be applicable in the case of high chloride concentrations (i.e. around 10 g/l)

d.

Anoxic/anaerobic biological treatment

Mercury (Hg), nitrate (NO3 ), nitrite (NO2 )

Generally applicable

e.

Coagulation and flocculation

Suspended solids

Generally applicable

f.

Crystallisation

Metals and metalloids, sulphate (SO4 2–), fluoride (F)

Generally applicable

g.

Filtration (e.g. sand filtration, microfiltration, ultrafiltration)

Suspended solids, metals

Generally applicable

h.

Flotation

Suspended solids, free oil

Generally applicable

i.

Ion exchange

Metals

Generally applicable

j.

Neutralisation

Acids, alkalis

Generally applicable

k.

Oxidation

Sulphide (S2–), sulphite (SO3 2–)

Generally applicable

l.

Precipitation

Metals and metalloids, sulphate (SO4 2–), fluoride (F)

Generally applicable

m.

Sedimentation

Suspended solids

Generally applicable

n.

Stripping

Ammonia (NH3)

Generally applicable

The BAT-AELs refer to direct discharges to a receiving water body at the point where the emission leaves the installation.

Table 1

BAT-AELs for direct discharges to a receiving water body from flue-gas treatment

Substance/Parameter

BAT-AELs

Daily average

Total organic carbon (TOC)

20–50 mg/l (30)  (31)  (32)

Chemical oxygen demand (COD)

60–150 mg/l (30)  (31)  (32)

Total suspended solids (TSS)

10–30 mg/l

Fluoride (F)

10–25 mg/l (32)

Sulphate (SO4 2–)

1,3–2,0 g/l (32)  (33)  (34)  (35)

Sulphide (S2–), easily released

0,1–0,2 mg/l (32)

Sulphite (SO3 2–)

1–20 mg/l (32)

Metals and metalloids

As

10–50 μg/l

Cd

2–5 μg/l

Cr

10–50 μg/l

Cu

10–50 μg/l

Hg

0,2–3 μg/l

Ni

10–50 μg/l

Pb

10–20 μg/l

Zn

50–200 μg/l

1.6.   Waste management

BAT 16.

In order to reduce the quantity of waste sent for disposal from the combustion and/or gasification process and abatement techniques, BAT is to organise operations so as to maximise, in order of priority and taking into account life-cycle thinking:

(a)

waste prevention, e.g. maximise the proportion of residues which arise as by-products;

(b)

waste preparation for reuse, e.g. according to the specific requested quality criteria;

(c)

waste recycling;

(d)

other waste recovery (e.g. energy recovery),

by implementing an appropriate combination of techniques such as:

Technique

Description

Applicability

a.

Generation of gypsum as a by-product

Quality optimisation of the calcium-based reaction residues generated by the wet FGD so that they can be used as a substitute for mined gypsum (e.g. as raw material in the plasterboard industry). The quality of limestone used in the wet FGD influences the purity of the gypsum produced

Generally applicable within the constraints associated with the required gypsum quality, the health requirements associated to each specific use, and by the market conditions

b.

Recycling or recovery of residues in the construction sector

Recycling or recovery of residues (e.g. from semi-dry desulphurisation processes, fly ash, bottom ash) as a construction material (e.g. in road building, to replace sand in concrete production, or in the cement industry)

Generally applicable within the constraints associated with the required material quality (e.g. physical properties, content of harmful substances) associated to each specific use, and by the market conditions

c.

Energy recovery by using waste in the fuel mix

The residual energy content of carbon-rich ash and sludges generated by the combustion of coal, lignite, heavy fuel oil, peat or biomass can be recovered for example by mixing with the fuel

Generally applicable where plants can accept waste in the fuel mix and are technically able to feed the fuels into the combustion chamber

d.

Preparation of spent catalyst for reuse

Preparation of catalyst for reuse (e.g. up to four times for SCR catalysts) restores some or all of the original performance, extending the service life of the catalyst to several decades. Preparation of spent catalyst for reuse is integrated in a catalyst management scheme

The applicability may be limited by the mechanical condition of the catalyst and the required performance with respect to controlling NOX and NH3 emissions

1.7.   Noise emissions

BAT 17.

In order to reduce noise emissions, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Operational measures

These include:

improved inspection and maintenance of equipment

closing of doors and windows of enclosed areas, if possible

equipment operated by experienced staff

avoidance of noisy activities at night, if possible

provisions for noise control during maintenance activities

Generally applicable

b.

Low-noise equipment

This potentially includes compressors, pumps and disks

Generally applicable when the equipment is new or replaced

c.

Noise attenuation

Noise propagation can be reduced by inserting obstacles between the emitter and the receiver. Appropriate obstacles include protection walls, embankments and buildings

Generally applicable to new plants. In the case of existing plants, the insertion of obstacles may be restricted by lack of space

d.

Noise-control equipment

This includes:

noise-reducers

equipment insulation

enclosure of noisy equipment

soundproofing of buildings

The applicability may be restricted by lack of space

e.

Appropriate location of equipment and buildings

Noise levels can be reduced by increasing the distance between the emitter and the receiver and by using buildings as noise screens

Generally applicable to new plants. In the case of existing plants, the relocation of equipment and production units may be restricted by lack of space or by excessive costs

2.   BAT CONCLUSIONS FOR THE COMBUSTION OF SOLID FUELS

2.1.   BAT conclusions for the combustion of coal and/or lignite

Unless otherwise stated, the BAT conclusions presented in this section are generally applicable to the combustion of coal and/or lignite. They apply in addition to the general BAT conclusions given in Section 1.

2.1.1.   General environmental performance

BAT 18.

In order to improve the general environmental performance of the combustion of coal and/or lignite, and in addition to BAT 6, BAT is to use the technique given below.

Technique

Description

Applicability

a.

Integrated combustion process ensuring high boiler efficiency and including primary techniques for NOX reduction (e.g. air staging, fuel staging, low-NOX burners (LNB) and/or flue-gas recirculation)

Combustion processes such as pulverised combustion, fluidised bed combustion or moving grate firing allow this integration

Generally applicable

2.1.2.   Energy efficiency

BAT 19.

In order to increase the energy efficiency of the combustion of coal and/or lignite, BAT is to use an appropriate combination of the techniques given in BAT 12 and below.

Technique

Description

Applicability

a.

Dry bottom ash handling

Dry hot bottom ash falls from the furnace onto a mechanical conveyor system and, after redirection to the furnace for reburning, is cooled down by ambient air. Useful energy is recovered from both the ash reburning and ash cooling

There may be technical restrictions that prevent retrofitting to existing combustion units


Table 2

BAT-associated energy efficiency levels (BAT-AEELs) for coal and/or lignite combustion

Type of combustion unit

BAT-AEELs (36)  (37)

Net electrical efficiency (%) (38)

Net total fuel utilisation (%) (38)  (39)  (40)

New unit (41)  (42)

Existing unit (41)  (43)

New or existing unit

Coal-fired, ≥ 1 000  MWth

45 – 46

33,5 – 44

75 – 97

Lignite-fired, ≥ 1 000  MWth

42 – 44 (44)

33,5 – 42,5

75 – 97

Coal-fired, < 1 000  MWth

36,5 – 41,5 (45)

32,5 – 41,5

75 – 97

Lignite-fired, < 1 000  MWth

36,5 – 40 (46)

31,5 – 39,5

75 – 97

2.1.3.   NOX, N2O and CO emissions to air

BAT 20.

In order to prevent or reduce NOX emissions to air while limiting CO and N2O emissions to air from the combustion of coal and/or lignite, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Combustion optimisation

See description in Section 8.3.

Generally used in combination with other techniques

Generally applicable

b.

Combination of other primary techniques for NOX reduction (e.g. air staging, fuel staging, flue-gas recirculation, low-NOX burners (LNB))

See description in Section 8.3 for each single technique.

The choice and performance of (an) appropriate (combination of) primary techniques may be influenced by the boiler design

c.

Selective non-catalytic reduction (SNCR)

See description in Section 8.3.

Can be applied with ‘slip’ SCR

The applicability may be limited in the case of boilers with a high cross-sectional area preventing homogeneous mixing of NH3 and NOX.

The applicability may be limited in the case of combustion plants operated < 1 500  h/yr with highly variable boiler loads

d.

Selective catalytic reduction (SCR)

See description in Section 8.3

Not applicable to combustion plants of < 300 MWth operated < 500 h/yr.

Not generally applicable to combustion plants of < 100 MWth.

There may be technical and economic restrictions for retrofitting existing combustion plants operated between 500 h/yr and 1 500  h/yr and for existing combustion plants of ≥ 300 MWth operated < 500 h/yr

e.

Combined techniques for NOX and SOX reduction

See description in Section 8.3

Applicable on a case-by-case basis, depending on the fuel characteristics and combustion process


Table 3

BAT-associated emission levels (BAT-AELs) for NOX emissions to air from the combustion of coal and/or lignite

Combustion plant total rated thermal input

(MWth)

BAT-AELs (mg/Nm3)

Yearly average

Daily average or average over the sampling period

New plant

Existing plant (47)

New plant

Existing plant (48)  (49)

< 100

100–150

100–270

155–200

165–330

100–300

50–100

100–180

80–130

155–210

≥ 300, FBC boiler combusting coal and/or lignite and lignite-fired PC boiler

50 – 85

< 85 – 150 (50)  (51)

80 – 125

140 – 165 (52)

≥ 300, coal-fired PC boiler

65 – 85

65 – 150

80 – 125

< 85 – 165 (53)

As an indication, the yearly average CO emission levels for existing combustion plants operated ≥ 1 500 h/yr or for new combustion plants will generally be as follows:

Combustion plant total rated thermal input (MWth)

CO indicative emission level (mg/Nm3)

< 300

< 30–140

≥ 300, FBC boiler combusting coal and/or lignite and lignite-fired PC boiler

< 30–100 (54)

≥ 300, coal-fired PC boiler

< 5–100 (54)

2.1.4.   SOX, HCl and HF emissions to air

BAT 21.

In order to prevent or reduce SOX, HCl and HF emissions to air from the combustion of coal and/or lignite, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Boiler sorbent injection (in-furnace or in-bed)

See description in Section 8.4

Generally applicable

b.

Duct sorbent injection (DSI)

See description in Section 8.4.

The technique can be used for HCl/HF removal when no specific FGD end-of-pipe technique is implemented

c.

Spray dry absorber (SDA)

See description in Section 8.4

d.

Circulating fluidised bed (CFB) dry scrubber

e.

Wet scrubbing

See description in Section 8.4.

The techniques can be used for HCl/HF removal when no specific FGD end-of-pipe technique is implemented

f.

Wet flue-gas desulphurisation (wet FGD)

See description in Section 8.4

Not applicable to combustion plants operated < 500 h/yr.

There may be technical and economic restrictions for applying the technique to combustion plants of < 300 MWth, and for retrofitting existing combustion plants operated between 500 h/yr and 1 500  h/yr

g.

Seawater FGD

h.

Combined techniques for NOX and SOX reduction

Applicable on a case-by-case basis, depending on the fuel characteristics and combustion process

i.

Replacement or removal of the gas-gas heater located downstream of the wet FGD

Replacement of the gas-gas heater downstream of the wet FGD by a multi-pipe heat extractor, or removal and discharge of the flue-gas via a cooling tower or a wet stack

Only applicable when the heat exchanger needs to be changed or replaced in combustion plants fitted with wet FGD and a downstream gas-gas heater

j.

Fuel choice

See description in Section 8.4.

Use of fuel with low sulphur (e.g. down to 0,1 wt-%, dry basis), chlorine or fluorine content

Applicable within the constraints associated with the availability of different types of fuel, which may be impacted by the energy policy of the Member State. The applicability may be limited due to design constraints in the case of combustion plants combusting highly specific indigenous fuels


Table 4

BAT-associated emission levels (BAT-AELs) for SO2 emissions to air from the combustion of coal and/or lignite

Combustion plant total rated thermal input

(MWth)

BAT-AELs (mg/Nm3)

Yearly average

Daily average

Daily average or average over the sampling period

New plant

Existing plant (55)

New plant

Existing plant (56)

< 100

150–200

150–360

170–220

170–400

100–300

80–150

95–200

135–200

135–220 (57)

≥ 300, PC boiler

10–75

10–130 (58)

25–110

25–165 (59)

≥ 300, Fluidised bed boiler (60)

20–75

20–180

25–110

50–220

For a combustion plant with a total rated thermal input of more than 300 MW, which is specifically designed to fire indigenous lignite fuels and which can demonstrate that it cannot achieve the BAT-AELs mentioned in Table 4 for techno-economic reasons, the daily average BAT-AELs set out in Table 4 do not apply, and the upper end of the yearly average BAT-AEL range is as follows:

(i)

for a new FGD system: RCG × 0,01 with a maximum of 200 mg/Nm3;

(ii)

for an existing FGD system: RCG × 0,03 with a maximum of 320 mg/Nm3;

in which RCG represents the concentration of SO2 in the raw flue-gas as a yearly average (under the standard conditions given under General considerations) at the inlet of the SOX abatement system, expressed at a reference oxygen content of 6 vol- % O2.

(iii)

If boiler sorbent injection is applied as part of the FGD system, the RCG may be adjusted by taking into account the SO2 reduction efficiency of this technique (ηBSI), as follows: RCG (adjusted) = RCG (measured)/(1-ηBSI).

Table 5

BAT-associated emission levels (BAT-AELs) for HCl and HF emissions to air from the combustion of coal and/or lignite

Pollutant

Combustion plant total rated thermal input

(MWth)

BAT-AELs (mg/Nm3)

Yearly average or average of samples obtained during one year

New plant

Existing plant (61)

HCl

< 100

1–6

2–10 (62)

≥ 100

1–3

1–5 (62)  (63)

HF

< 100

< 1–3

< 1–6 (64)

≥ 100

< 1–2

< 1–3 (64)

2.1.5.   Dust and particulate-bound metal emissions to air

BAT 22.

In order to reduce dust and particulate-bound metal emissions to air from the combustion of coal and/or lignite, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Electrostatic precipitator (ESP)

See description in Section 8.5

Generally applicable

b.

Bag filter

c.

Boiler sorbent injection

(in-furnace or in-bed)

See descriptions in Section 8.5.

The techniques are mainly used for SOX, HCl and/or HF control

d.

Dry or semi-dry FGD system

e.

Wet flue-gas desulphurisation (wet FGD)

See applicability in BAT 21


Table 6

BAT-associated emission levels (BAT-AELs) for dust emissions to air from the combustion of coal and/or lignite

Combustion plant total rated thermal input

(MWth)

BAT-AELs (mg/Nm3)

Yearly average

Daily average or average over the sampling period

New plant

Existing plant (65)

New plant

Existing plant (66)

< 100

2–5

2–18

4–16

4–22 (67)

100–300

2–5

2–14

3–15

4–22 (68)

300–1 000

2–5

2–10 (69)

3–10

3–11 (70)

≥ 1 000

2–5

2–8

3–10

3–11 (71)

2.1.6.   Mercury emissions to air

BAT 23.

In order to prevent or reduce mercury emissions to air from the combustion of coal and/or lignite, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

Co-benefit from techniques primarily used to reduce emissions of other pollutants

a.

Electrostatic precipitator (ESP)

See description in Section 8.5.

Higher mercury removal efficiency is achieved at flue-gas temperatures below 130 °C.

The technique is mainly used for dust control

Generally applicable

b.

Bag filter

See description in Section 8.5.

The technique is mainly used for dust control

c.

Dry or semi-dry FGD system

See descriptions in Section 8.5.

The techniques are mainly used for SOX, HCl and/or HF control

d.

Wet flue-gas desulphurisation (wet FGD)

See applicability in BAT 21

e.

Selective catalytic reduction (SCR)

See description in Section 8.3.

Only used in combination with other techniques to enhance or reduce the mercury oxidation before capture in a subsequent FGD or dedusting system.

The technique is mainly used for NOX control

See applicability in BAT 20

Specific techniques to reduce mercury emissions

f.

Carbon sorbent (e.g. activated carbon or halogenated activated carbon) injection in the flue-gas

See description in Section 8.5.

Generally used in combination with an ESP/bag filter. The use of this technique may require additional treatment steps to further segregate the mercury-containing carbon fraction prior to further reuse of the fly ash

Generally applicable

g.

Use of halogenated additives in the fuel or injected in the furnace

See description in Section 8.5

Generally applicable in the case of a low halogen content in the fuel

h.

Fuel pretreatment

Fuel washing, blending and mixing in order to limit/reduce the mercury content or improve mercury capture by pollution control equipment

Applicability is subject to a previous survey for characterising the fuel and for estimating the potential effectiveness of the technique

i.

Fuel choice

See description in Section 8.5

Applicable within the constraints associated with the availability of different types of fuel, which may be impacted by the energy policy of the Member State


Table 7

BAT-associated emission levels (BAT-AELs) for mercury emissions to air from the combustion of coal and lignite

Combustion plant total rated thermal input

(MWth)

BAT-AELs (μg/Nm3)

Yearly average or average of samples obtained during one year

New plant

Existing plant (72)

coal

lignite

coal

lignite

< 300

< 1–3

< 1–5

< 1–9

< 1–10

≥ 300

< 1–2

< 1–4

< 1–4

< 1–7

2.2.   BAT conclusions for the combustion of solid biomass and/or peat

Unless otherwise stated, the BAT conclusions presented in this section are generally applicable to the combustion of solid biomass and/or peat. They apply in addition to the general BAT conclusions given in Section 1

2.2.1.   Energy efficiency

Table 8

BAT-associated energy efficiency levels (BAT-AEELs) for the combustion of solid biomass and/or peat

Type of combustion unit

BAT-AEELs (73)  (74)

Net electrical efficiency (%) (75)

Net total fuel utilisation (%) (76)  (77)

New unit (78)

Existing unit

New unit

Existing unit

Solid biomass and/or peat boiler

33,5–to > 38

28–38

73–99

73–99

2.2.2.   NOX, N2O and CO emissions to air

BAT 24.

In order to prevent or reduce NOX emissions to air while limiting CO and N2O emissions to air from the combustion of solid biomass and/or peat, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Combustion optimisation

See descriptions in Section 8.3

Generally applicable

b.

Low-NOX burners (LNB)

c.

Air staging

d.

Fuel staging

e.

Flue-gas recirculation

f.

Selective non-catalytic reduction (SNCR)

See description in Section 8.3.

Can be applied with ‘slip’ SCR

Not applicable to combustion plants operated < 500 h/yr with highly variable boiler loads.

The applicability may be limited in the case of combustion plants operated between 500 h/yr and 1 500  h/yr with highly variable boiler loads.

For existing combustion plants, applicable within the constraints associated with the required temperature window and residence time for the injected reactants

g.

Selective catalytic reduction (SCR)

See description in Section 8.3.

The use of high-alkali fuels (e.g. straw) may require the SCR to be installed downstream of the dust abatement system

Not applicable to combustion plants operated < 500 h/yr.

There may be economic restrictions for retrofitting existing combustion plants of < 300 MWth.

Not generally applicable to existing combustion plants of < 100 MWth


Table 9

BAT-associated emission levels (BAT-AELs) for NOX emissions to air from the combustion of solid biomass and/or peat

Combustion plant total rated thermal input

(MWth)

BAT-AELs (mg/Nm3)

Yearly average

Daily average or average over the sampling period

New plant

Existing plant (79)

New plant

Existing plant (80)

50–100

70–150 (81)

70–225 (82)

120–200 (83)

120–275 (84)

100–300

50–140

50–180

100–200

100–220

≥ 300

40–140

40–150 (85)

65–150

95–165 (86)

As an indication, the yearly average CO emission levels will generally be:

< 30–250 mg/Nm3 for existing combustion plants of 50–100 MWth operated ≥ 1 500 h/yr, or new combustion plants of 50–100 MWth,

< 30–160 mg/Nm3 for existing combustion plants of 100–300 MWth operated ≥ 1 500 h/yr, or new combustion plants of 100–300 MWth,

< 30–80 mg/Nm3 for existing combustion plants of ≥ 300 MWth operated ≥ 1 500 h/yr, or new combustion plants of ≥ 300 MWth.

2.2.3.   SOX, HCl and HF emissions to air

BAT 25.

In order to prevent or reduce SOX, HCl and HF emissions to air from the combustion of solid biomass and/or peat, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Boiler sorbent injection (in-furnace or in-bed)

See descriptions in Section 8.4

Generally applicable

b.

Duct sorbent injection (DSI)

c.

Spray dry absorber (SDA)

d.

Circulating fluidised bed (CFB) dry scrubber

e.

Wet scrubbing

f.

Flue-gas condenser

g.

Wet flue-gas desulphurisation (wet FGD)

Not applicable to combustion plants operated < 500 h/yr.

There may be technical and economic restrictions for retrofitting existing combustion plants operated between 500 h/yr and 1 500  h/yr

h.

Fuel choice

Applicable within the constraints associated with the availability of different types of fuel, which may be impacted by the energy policy of the Member State


Table 10

BAT-associated emission levels (BAT-AELs) for SO2 emissions to air from the combustion of solid biomass and/or peat

Combustion plant total rated thermal input

(MWth)

BAT-AELs for SO2 (mg/Nm3)

Yearly average

Daily average or average over the sampling period

New plant

Existing plant (87)

New plant

Existing plant (88)

< 100

15–70

15–100

30–175

30–215

100–300

< 10–50

< 10–70 (89)

< 20–85

< 20–175 (90)

≥ 300

< 10–35

< 10–50 (89)

< 20–70

< 20–85 (91)


Table 11

BAT-associated emission levels (BAT-AELs) for HCl and HF emissions to air from the combustion of solid biomass and/or peat

Combustion plant total rated thermal input

(MWth)

BAT-AELs for HCl (mg/Nm3) (92)  (93)

BAT-AELs for HF (mg/Nm3)

Yearly average or average of samples obtained during one year

Daily average or average over the sampling period

Average over the sampling period

New plant

Existing plant (94)  (95)

New plant

Existing plant (96)

New plant

Existing plant (96)

< 100

1–7

1–15

1–12

1–35

< 1

< 1,5

100–300

1–5

1–9

1–12

1–12

< 1

< 1

≥ 300

1–5

1–5

1–12

1–12

< 1

< 1

2.2.4.   Dust and particulate-bound metal emissions to air

BAT 26.

In order to reduce dust and particulate-bound metal emissions to air from the combustion of solid biomass and/or peat, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Electrostatic precipitator (ESP)

See description in Section 8.5

Generally applicable

b.

Bag filter

c.

Dry or semi-dry FGD system

See descriptions in Section 8.5

The techniques are mainly used for SOX, HCl and/or HF control

d.

Wet flue-gas desulphurisation (wet FGD)

See applicability in BAT 25

e.

Fuel choice

See description in Section 8.5

Applicable within the constraints associated with the availability of different types of fuel, which may be impacted by the energy policy of the Member State


Table 12

BAT-associated emission levels (BAT-AELs) for dust emissions to air from the combustion of solid biomass and/or peat

Combustion plant total rated thermal input

(MWth)

BAT-AELs for dust (mg/Nm3)

Yearly average

Daily average or average over the sampling period

New plant

Existing plant (97)

New plant

Existing plant (98)

< 100

2–5

2–15

2–10

2–22

100–300

2–5

2–12

2–10

2–18

≥ 300

2–5

2–10

2–10

2–16

2.2.5.   Mercury emissions to air

BAT 27.

In order to prevent or reduce mercury emissions to air from the combustion of solid biomass and/or peat, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

Specific techniques to reduce mercury emissions

a.

Carbon sorbent (e.g. activated carbon or halogenated activated carbon) injection in the flue-gas

See descriptions in Section 8.5

Generally applicable

b.

Use of halogenated additives in the fuel or injected in the furnace

Generally applicable in the case of a low halogen content in the fuel

c.

Fuel choice

Applicable within the constraints associated with the availability of different types of fuel, which may be impacted by the energy policy of the Member State

Co-benefit from techniques primarily used to reduce emissions of other pollutants

d.

Electrostatic precipitator (ESP)

See descriptions in Section 8.5.

The techniques are mainly used for dust control

Generally applicable

e.

Bag filter

f.

Dry or semi-dry FGD system

See descriptions in Section 8.5.

The techniques are mainly used for SOX, HCl and/or HF control

g.

Wet flue-gas desulphurisation (wet FGD)

See applicability in BAT 25

The BAT-associated emission level (BAT-AEL) for mercury emissions to air from the combustion of solid biomass and/or peat is < 1–5 μg/Nm3 as average over the sampling period.

3.   BAT CONCLUSIONS FOR THE COMBUSTION OF LIQUID FUELS

The BAT conclusions presented in this section do not apply to combustion plants on offshore platforms; these are covered by Section 4.3

3.1.   HFO- and/or gas-oil-fired boilers

Unless otherwise stated, the BAT conclusions presented in this section are generally applicable to the combustion of HFO and/or gas oil in boilers. They apply in addition to the general BAT conclusions given in Section 1

3.1.1.   Energy efficiency

Table 13

BAT-associated energy efficiency levels (BAT-AEELs) for HFO and/or gas oil combustion in boilers

Type of combustion unit

BAT-AEELs (99)  (100)

Net electrical efficiency (%)

Net total fuel utilisation (%) (101)

New unit

Existing unit

New unit

Existing unit

HFO- and/or gas-oil-fired boiler

> 36,4

35,6–37,4

80–96

80–96

3.1.2.   NOX and CO emissions to air

BAT 28.

In order to prevent or reduce NOX emissions to air while limiting CO emissions to air from the combustion of HFO and/or gas oil in boilers, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Air staging

See descriptions in Section 8.3

Generally applicable

b.

Fuel staging

c.

Flue-gas recirculation

d.

Low-NOX burners (LNB)

e.

Water/steam addition

Applicable within the constraints of water availability

f.

Selective non-catalytic reduction (SNCR)

Not applicable to combustion plants operated < 500 h/yr with highly variable boiler loads.

The applicability may be limited in the case of combustion plants operated between 500 h/yr and 1 500  h/yr with highly variable boiler loads

g.

Selective catalytic reduction (SCR)

See descriptions in Section 8.3

Not applicable to combustion plants operated < 500 h/yr.

There may be technical and economic restrictions for retrofitting existing combustion plants operated between 500 h/yr and 1 500  h/yr.

Not generally applicable to combustion plants of < 100 MWth

h.

Advanced control system

Generally applicable to new combustion plants. The applicability to old combustion plants may be constrained by the need to retrofit the combustion system and/or control command system

i.

Fuel choice

Applicable within the constraints associated with the availability of different types of fuel, which may be impacted by the energy policy of the Member State


Table 14

BAT-associated emission levels (BAT-AELs) for NOX emissions to air from the combustion of HFO and/or gas oil in boilers

Combustion plant total rated thermal input

(MWth)

BAT-AELs (mg/Nm3)

Yearly average

Daily average or average over the sampling period

New plant

Existing plant (102)

New plant

Existing plant (103)

< 100

75–200

150–270

100–215

210–330 (104)

≥ 100

45–75

45–100 (105)

85–100

85–110 (106)  (107)

As an indication, the yearly average CO emission levels will generally be:

10-30 mg/Nm3 for existing combustion plants of < 100 MWth operated ≥ 1 500 h/yr, or new combustion plants of <100 MWth,

10–20mg/Nm3 for existing combustion plants of ≥ 100 MWth operated ≥ 1 500 h/yr, or new combustion plants of ≥ 100 MWth.

3.1.3.   SOX, HCl and HF emissions to air

BAT 29.

In order to prevent or reduce SOX, HCl and HF emissions to air from the combustion of HFO and/or gas oil in boilers, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Duct sorbent injection (DSI)

See description in Section 8.4

Generally applicable

b.

Spray dry absorber (SDA)

c.

Flue-gas condenser

d.

Wet flue-gas desulphurisation

(wet FGD)

There may be technical and economic restrictions for applying the technique to combustion plants of < 300 MWth.

Not applicable to combustion plants operated < 500 h/yr.

There may be technical and economic restrictions for retrofitting existing combustion plants operated between 500 h/yr and 1 500  h/yr

e.

Seawater FGD

There may be technical and economic restrictions for applying the technique to combustion plants of < 300 MWth.

Not applicable to combustion plants operated < 500 h/yr.

There may be technical and economic restrictions for retrofitting existing combustion plants operated between 500 h/yr and 1 500  h/yr

f.

Fuel choice

Applicable within the constraints associated with the availability of different types of fuel, which may be impacted by the energy policy of the Member State


Table 15

BAT-associated emission levels (BAT-AELs) for SO2 emissions to air from the combustion of HFO and/or gas oil in boilers

Combustion plant total rated thermal input

(MWth)

BAT-AELs for SO2 (mg/Nm3)

Yearly average

Daily average or average over the sampling period

New plant

Existing plant (108)

New plant

Existing plant (109)

< 300

50–175

50–175

150–200

150–200 (110)

≥ 300

35–50

50–110

50–120

150–165 (111)  (112)

3.1.4.   Dust and particulate-bound metal emissions to air

BAT 30.

In order to reduce dust and particulate-bound metal emissions to air from the combustion of HFO and/or gas oil in boilers, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Electrostatic precipitator (ESP)

See description in Section 8.5

Generally applicable

b.

Bag filter

c.

Multicyclones

See description in Section 8.5.

Multicyclones can be used in combination with other dedusting techniques

d.

Dry or semi-dry FGD system

See descriptions in Section 8.5.

The technique is mainly used for SOX, HCl and/or HF control

e.

Wet flue-gas desulphurisation (wet FGD)

See description in Section 8.5.

The technique is mainly used for SOX, HCl and/or HF control

See applicability in BAT 29

f.

Fuel choice

See description in Section 8.5

Applicable within the constraints associated with the availability of different types of fuel, which may be impacted by the energy policy of the Member State


Table 16

BAT-associated emission levels (BAT-AELs) for dust emissions to air from the combustion of HFO and/or gas oil in boilers

Combustion plant total rated thermal input

(MWth)

BAT-AELs for dust (mg/Nm3)

Yearly average

Daily average or average over the sampling period

New plant

Existing plant (113)

New plant

Existing plant (114)

< 300

2–10

2–20

7–18

7–22 (115)

≥ 300

2–5

2–10

7–10

7–11 (116)

3.2.   HFO- and/or gas-oil-fired engines

Unless otherwise stated, the BAT conclusions presented in this section are generally applicable to the combustion of HFO and/or gas oil in reciprocating engines. They apply in addition to the general BAT conclusions given in Section 1.

As regards HFO- and/or gas-oil-fired engines, secondary abatement techniques for NOX, SO2 and dust may not be applicable to engines in islands that are part of a small isolated system (117) or a micro isolated system (118), due to technical, economic and logistical/infrastructure constraints, pending their interconnection to the mainland electricity grid or access to a natural gas supply. The BAT-AELs for such engines shall therefore only apply in small isolated system and micro isolated system as from 1 January 2025 for new engines, and as from 1 January 2030 for existing engines.

3.2.1.   Energy efficiency

BAT 31.

In order to increase the energy efficiency of HFO and/or gas oil combustion in reciprocating engines, BAT is to use an appropriate combination of the techniques given in BAT 12 and below.

Technique

Description

Applicability

a.

Combined cycle

See description in Section 8.2

Generally applicable to new units operated ≥ 1 500  h/yr.

Applicable to existing units within the constraints associated with the steam cycle design and the space availability.

Not applicable to existing units operated < 1 500  h/yr


Table 17

BAT-associated energy efficiency levels (BAT-AEELs) for the combustion of HFO and/or gas oil in reciprocating engines

Type of combustion unit

BAT-AEELs (119)

Net electrical efficiency (%) (120)

New unit

Existing unit

HFO- and/or gas-oil-fired reciprocating engine — single cycle

41,5–44,5 (121)

38,3–44,5 (121)

HFO- and/or gas-oil-fired reciprocating engine — combined cycle

> 48 (122)

No BAT-AEEL

3.2.2.   NOX, CO and volatile organic compound emissions to air

BAT 32.

In order to prevent or reduce NOX emissions to air from the combustion of HFO and/or gas oil in reciprocating engines, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Low-NOX combustion concept in diesel engines

See descriptions in Section 8.3

Generally applicable

b.

Exhaust-gas recirculation (EGR)

Not applicable to four-stroke engines

c.

Water/steam addition

Applicable within the constraints of water availability.

The applicability may be limited where no retrofit package is available

d.

Selective catalytic reduction (SCR)

Not applicable to combustion plants operated < 500 h/yr.

There may be technical and economic restrictions for retrofitting existing combustion plants operated between 500 h/yr and 1 500  h/yr.

Retrofitting existing combustion plants may be constrained by the availability of sufficient space

BAT 33.

In order to prevent or reduce emissions of CO and volatile organic compounds to air from the combustion of HFO and/or gas oil in reciprocating engines, BAT is to use one or both of the techniques given below.

Technique

Description

Applicability

a.

Combustion optimisation

 

Generally applicable

b.

Oxidation catalysts

See descriptions in Section 8.3

Not applicable to combustion plants operated < 500 h/yr.

The applicability may be limited by the sulphur content of the fuel


Table 18

BAT-associated emission levels (BAT-AELs) for NOX emissions to air from the combustion of HFO and/or gas oil in reciprocating engines

Combustion plant total rated thermal input

(MWth)

BAT-AELs (mg/Nm3)

Yearly average

Daily average or average over the sampling period

New plant

Existing plant (123)

New plant

Existing plant (124)  (125)

≥ 50

115–190 (126)

125–625

145–300

150–750

As an indication, for existing combustion plants burning only HFO and operated ≥ 1 500 h/yr or new combustion plants burning only HFO,

the yearly average CO emission levels will generally be 50–175 mg/Nm3,

the average over the sampling period for TVOC emission levels will generally be 10–40 mg/Nm3.

3.2.3.   SOX, HCl and HF emissions to air

BAT 34.

In order to prevent or reduce SOX, HCl and HF emissions to air from the combustion of HFO and/or gas oil in reciprocating engines, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Fuel choice

See descriptions in Section 8.4

Applicable within the constraints associated with the availability of different types of fuel, which may be impacted by the energy policy of the Member State

b.

Duct sorbent injection (DSI)

There may be technical restrictions in the case of existing combustion plants

Not applicable to combustion plants operated < 500 h/yr

c.

Wet flue-gas desulphurisation (wet FGD)

There may be technical and economic restrictions for applying the technique to combustion plants of < 300 MWth.

Not applicable to combustion plants operated < 500 h/yr.

There may be technical and economic restrictions for retrofitting existing combustion plants operated between 500 h/yr and 1 500  h/yr


Table 19

BAT-associated emission levels (BAT-AELs) for SO2 emissions to air from the combustion of HFO and/or gas oil in reciprocating engines

Combustion plant total rated thermal input

(MWth)

BAT-AELs for SO2 (mg/Nm3)

Yearly average

Daily average or average over the sampling period

New plant

Existing plant (127)

New plant

Existing plant (128)

All sizes

45–100

100–200 (129)

60–110

105–235 (129)

3.2.4.   Dust and particulate-bound metal emissions to air

BAT 35.

In order to prevent or reduce dust and particulate-bound metal emissions from the combustion of HFO and/or gas oil in reciprocating engines, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Fuel choice

See descriptions in Section 8.5

Applicable within the constraints associated with the availability of different types of fuel, which may be impacted by the energy policy of the Member State

b.

Electrostatic precipitator (ESP)

Not applicable to combustion plants operated < 500 h/yr

c.

Bag filter


Table 20

BAT-associated emission levels (BAT-AELs) for dust emissions to air from the combustion of HFO and/or gas oil in reciprocating engines

Combustion plant total rated thermal input

(MWth)

BAT-AELs for dust (mg/Nm3)

Yearly average

Daily average or average over the sampling period

New plant

Existing plant (130)

New plant

Existing plant (131)

≥ 50

5–10

5–35

10–20

10–45

3.3.   Gas-oil-fired gas turbines

Unless stated otherwise, the BAT conclusions presented in this section are generally applicable to the combustion of gas oil in gas turbines. They apply in addition to the general BAT conclusions given in Section 1.

3.3.1.   Energy efficiency

BAT 36.

In order to increase the energy efficiency of gas oil combustion in gas turbines, BAT is to use an appropriate combination of the techniques given in BAT 12 and below.

Technique

Description

Applicability

a.

Combined cycle

See description in Section 8.2

Generally applicable to new units operated ≥ 1 500  h/yr.

Applicable to existing units within the constraints associated with the steam cycle design and the space availability.

Not applicable to existing units operated < 1 500  h/yr


Table 21

BAT-associated energy efficiency levels (BAT-AEELs) for gas-oil-fired gas turbines

Type of combustion unit

BAT-AEELs (132)

Net electrical efficiency (%) (133)

New unit

Existing unit

Gas-oil-fired open-cycle gas turbine

> 33

25–35,7

Gas-oil-fired combined cycle gas turbine

> 40

33–44

3.3.2.   NOX and CO emissions to air

BAT 37.

In order to prevent or reduce NOX emissions to air from the combustion of gas oil in gas turbines, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Water/steam addition

See description in Section 8.3

The applicability may be limited due to water availability

b.

Low-NOX burners (LNB)

Only applicable to turbine models for which low-NOX burners are available on the market

c.

Selective catalytic reduction (SCR)

Not applicable to combustion plants operated < 500 h/yr.

There may be technical and economic restrictions for retrofitting existing combustion plants operated between 500 h/yr and 1 500  h/yr.

Retrofitting existing combustion plants may be constrained by the availability of sufficient space

BAT 38.

In order to prevent or reduce CO emissions to air from the combustion of gas oil in gas turbines, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Combustion optimisation

See description in Section 8.3

Generally applicable

b.

Oxidation catalysts

Not applicable to combustion plants operated < 500 h/yr.

Retrofitting existing combustion plants may be constrained by the availability of sufficient space

As an indication, the emission level for NOX emissions to air from the combustion of gas oil in dual fuel gas turbines for emergency use operated < 500 h/yr will generally be 145–250 mg/Nm3 as a daily average or average over the sampling period.

3.3.3.   SOX and dust emissions to air

BAT 39.

In order to prevent or reduce SOX and dust emissions to air from the combustion of gas oil in gas turbines, BAT is to use the technique given below.

Technique

Description

Applicability

a.

Fuel choice

See description in Section 8.4

Applicable within the constraints associated with the availability of different types of fuel, which may be impacted by the energy policy of the Member State


Table 22

BAT-associated emission levels for SO2 and dust emissions to air from the combustion of gas oil in gas turbines, including dual fuel gas turbines

Type of combustion plant

BAT-AELs (mg/Nm3)

SO2

Dust

Yearly average (134)

Daily average or average over the sampling period (135)

Yearly average (134)

Daily average or average over the sampling period (135)

New and existing plants

35–60

50–66

2–5

2–10

4.   BAT CONCLUSIONS FOR THE COMBUSTION OF GASEOUS FUELS

4.1.   BAT conclusions for the combustion of natural gas

Unless otherwise stated, the BAT conclusions presented in this section are generally applicable to the combustion of natural gas. They apply in addition to the general BAT conclusions given in Section 1. They do not apply to combustion plants on offshore platforms; these are covered by Section. 4.3.

4.1.1.   Energy efficiency

BAT 40.

In order to increase the energy efficiency of natural gas combustion, BAT is to use an appropriate combination of the techniques given in BAT 12 and below.

Technique

Description

Applicability

a.

Combined cycle

See description in Section 8.2

Generally applicable to new gas turbines and engines except when operated < 1 500  h/yr.

Applicable to existing gas turbines and engines within the constraints associated with the steam cycle design and the space availability.

Not applicable to existing gas turbines and engines operated < 1 500  h/yr.

Not applicable to mechanical drive gas turbines operated in discontinuous mode with extended load variations and frequent start-ups and shutdowns.

Not applicable to boilers


Table 23

BAT-associated energy efficiency levels (BAT-AEELs) for the combustion of natural gas

Type of combustion unit

BAT-AEELs (136)  (137)

Net electrical efficiency (%)

Net total fuel utilisation (%) (138)  (139)

Net mechanical energy efficiency (%) (139)  (140)

New unit

Existing unit

New unit

Existing unit

Gas engine

39,5–44 (141)

35–44 (141)

56–85 (141)

No BAT-AEEL.

Gas-fired boiler

39–42,5

38–40

78–95

No BAT-AEEL.

Open cycle gas turbine, ≥ 50 MWth

36–41,5

33–41,5

No BAT-AEEL

36,5–41

33,5–41

Combined cycle gas turbine (CCGT)

CCGT, 50–600 MWth

53–58,5

46–54

No BAT-AEEL

No BAT-AEEL

CCGT, ≥ 600 MWth

57–60,5

50–60

No BAT-AEEL

No BAT-AEEL

CHP CCGT, 50–600 MWth

53–58,5

46–54

65–95

No BAT-AEEL

CHP CCGT, ≥ 600 MWth

57–60,5

50–60

65–95

No BAT-AEEL

4.1.2.   NOX, CO, NMVOC and CH4 emissions to air

BAT 41.

In order to prevent or reduce NOX emissions to air from the combustion of natural gas in boilers, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Air and/or fuel staging

See descriptions in Section 8.3.

Air staging is often associated with low-NOX burners

Generally applicable

b.

Flue-gas recirculation

See description in Section 8.3

c.

Low-NOX burners (LNB)

d.

Advanced control system

See description in Section 8.3.

This technique is often used in combination with other techniques or may be used alone for combustion plants operated < 500 h/yr

The applicability to old combustion plants may be constrained by the need to retrofit the combustion system and/or control command system

e.

Reduction of the combustion air temperature

See description in Section 8.3

Generally applicable within the constraints associated with the process needs

f.

Selective non–catalytic reduction (SNCR)

Not applicable to combustion plants operated < 500 h/yr with highly variable boiler loads.

The applicability may be limited in the case of combustion plants operated between 500 h/yr and 1 500  h/yr with highly variable boiler loads

g.

Selective catalytic reduction (SCR)

Not applicable to combustion plants operated < 500 h/yr.

Not generally applicable to combustion plants of < 100 MWth.

There may be technical and economic restrictions for retrofitting existing combustion plants operated between 500 h/yr and 1 500  h/yr

BAT 42.

In order to prevent or reduce NOX emissions to air from the combustion of natural gas in gas turbines, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Advanced control system

See description in Section 8.3.

This technique is often used in combination with other techniques or may be used alone for combustion plants operated < 500 h/yr

The applicability to old combustion plants may be constrained by the need to retrofit the combustion system and/or control command system

b.

Water/steam addition

See description in Section 8.3

The applicability may be limited due to water availability

c.

Dry low-NOX burners (DLN)

The applicability may be limited in the case of turbines where a retrofit package is not available or when water/steam addition systems are installed

d.

Low-load design concept

Adaptation of the process control and related equipment to maintain good combustion efficiency when the demand in energy varies, e.g. by improving the inlet airflow control capability or by splitting the combustion process into decoupled combustion stages

The applicability may be limited by the gas turbine design

e.

Low-NOX burners (LNB)

See description in Section 8.3

Generally applicable to supplementary firing for heat recovery steam generators (HRSGs) in the case of combined-cycle gas turbine (CCGT) combustion plants

f.

Selective catalytic reduction (SCR)

Not applicable in the case of combustion plants operated < 500 h/yr.

Not generally applicable to existing combustion plants of < 100 MWth.

Retrofitting existing combustion plants may be constrained by the availability of sufficient space.

There may be technical and economic restrictions for retrofitting existing combustion plants operated between 500 h/yr and 1 500  h/yr

BAT 43.

In order to prevent or reduce NOX emissions to air from the combustion of natural gas in engines, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Advanced control system

See description in Section 8.3.

This technique is often used in combination with other techniques or may be used alone for combustion plants operated < 500 h/yr

The applicability to old combustion plants may be constrained by the need to retrofit the combustion system and/or control command system

b.

Lean-burn concept

See description in Section 8.3.

Generally used in combination with SCR

Only applicable to new gas-fired engines

c.

Advanced lean-burn concept

See descriptions in Section 8.3

Only applicable to new spark plug ignited engines

d.

Selective catalytic reduction (SCR)

Retrofitting existing combustion plants may be constrained by the availability of sufficient space.

Not applicable to combustion plants operated < 500 h/yr.

There may be technical and economic restrictions for retrofitting existing combustion plants operated between 500 h/yr and 1 500  h/yr

BAT 44.

In order to prevent or reduce CO emissions to air from the combustion of natural gas, BAT is to ensure optimised combustion and/or to use oxidation catalysts.

Description

See descriptions in Section 8.3.

Table 24

BAT-associated emission levels (BAT-AELs) for NOX emissions to air from the combustion of natural gas in gas turbines

Type of combustion plant

Combustion plant total rated thermal input

(MWth)

BAT-AELs (mg/Nm3) (142)  (143)

Yearly average (144)  (145)

Daily average or average over the sampling period

Open-cycle gas turbines (OCGTs) (146)  (147)

New OCGT

≥ 50

15–35

25–50

Existing OCGT (excluding turbines for mechanical drive applications) — All but plants operated < 500 h/yr

≥ 50

15–50

25–55 (148)

Combined-cycle gas turbines (CCGTs) (146)  (149)

New CCGT

≥ 50

10–30

15–40

Existing CCGT with a net total fuel utilisation of < 75 %

≥ 600

10–40

18–50

Existing CCGT with a net total fuel utilisation of ≥ 75 %

≥ 600

10–50

18–55 (150)

Existing CCGT with a net total fuel utilisation of < 75 %

50–600

10–45

35–55

Existing CCGT with a net total fuel utilisation of ≥ 75 %

50–600

25–50 (151)

35–55 (152)

Open- and combined-cycle gas turbines

Gas turbine put into operation no later than 27 November 2003, or existing gas turbine for emergency use and operated < 500 h/yr

≥ 50

No BAT-AEL

60–140 (153)  (154)

Existing gas turbine for mechanical drive applications — All but plants operated < 500 h/yr

≥ 50

15–50 (155)

25–55 (156)

As an indication, the yearly average CO emission levels for each type of existing combustion plant operated ≥ 1 500 h/yr and for each type of new combustion plant will generally be as follows:

New OCGT of ≥ 50 MWth: < 5–40 mg/Nm3. For plants with a net electrical efficiency (EE) greater than 39 %, a correction factor may be applied to the higher end of this range, corresponding to [higher end] × EE/39, where EE is the net electrical energy efficiency or net mechanical energy efficiency of the plant determined at ISO baseload conditions.

Existing OCGT of ≥ 50 MWth (excluding turbines for mechanical drive applications): < 5–40 mg/Nm3. The higher end of this range will generally be 80 mg/Nm3 in the case of existing plants that cannot be fitted with dry techniques for NOX reduction, or 50 mg/Nm3 for plants that operate at low load.

New CCGT of ≥ 50 MWth: < 5–30 mg/Nm3. For plants with a net electrical efficiency (EE) greater than 55 %, a correction factor may be applied to the higher end of the range, corresponding to [higher end] × EE/55, where EE is the net electrical energy efficiency of the plant determined at ISO baseload conditions.

Existing CCGT of ≥ 50 MWth: < 5–30 mg/Nm3. The higher end of this range will generally be 50 mg/Nm3 for plants that operate at low load.

Existing gas turbines of ≥ 50 MWth for mechanical drive applications: < 5–40 mg/Nm3. The higher end of the range will generally be 50 mg/Nm3 when plants operate at low load.

In the case of a gas turbine equipped with DLN burners, these indicative levels correspond to when the DLN operation is effective.

Table 25

BAT-associated emission levels (BAT-AELs) for NOX emissions to air from the combustion of natural gas in boilers and engines

Type of combustion plant

BAT-AELs (mg/Nm3)

Yearly average (157)

Daily average or average over the sampling period

New plant

Existing plant (158)

New plant

Existing plant (159)

Boiler

10–60

50–100

30–85

85–110

Engine (160)

20–75

20–100

55–85

55–110 (161)

As an indication, the yearly average CO emission levels will generally be:

< 5–40 mg/Nm3 for existing boilers operated ≥ 1 500 h/yr,

< 5–15 mg/Nm3 for new boilers,

30–100 mg/Nm3 for existing engines operated ≥ 1 500 h/yr and for new engines.

BAT 45.

In order to reduce non-methane volatile organic compounds (NMVOC) and methane (CH4) emissions to air from the combustion of natural gas in spark-ignited lean-burn gas engines, BAT is to ensure optimised combustion and/or to use oxidation catalysts.

Description

See descriptions in Section 8.3. Oxidation catalysts are not effective at reducing the emissions of saturated hydrocarbons containing less than four carbon atoms.

Table 26

BAT-associated emission levels (BAT-AELs) for formaldehyde and CH4 emissions to air from the combustion of natural gas in a spark-ignited lean-burn gas engine

Combustion plant total rated thermal input (MWth)

BAT-AELs (mg/Nm3)

Formaldehyde

CH4

Average over the sampling period

New or existing plant

New plant

Existing plant

≥ 50

5–15 (162)

215–500 (163)

215–560 (162)  (163)

4.2.   BAT conclusions for the combustion of iron and steel process gases

Unless otherwise stated, the BAT conclusions presented in this section are generally applicable to the combustion of iron and steel process gases (blast furnace gas, coke oven gas, basic oxygen furnace gas), individually, in combination, or simultaneously with other gaseous and/or liquid fuels. They apply in addition to the general BAT conclusions given in Section 1.

4.2.1.   Energy efficiency

BAT 46.

In order to increase the energy efficiency of the combustion of iron and steel process gases, BAT is to use an appropriate combination of the techniques given in BAT 12 and below.

Technique

Description

Applicability

a.

Process gas management system

See description in Section 8.2

Only applicable to integrated steelworks


Table 27

BAT-associated energy efficiency levels (BAT-AEELs) for the combustion of iron and steel process gases in boilers

Type of combustion unit

BAT-AEELs (164)  (165)

Net electrical efficiency (%)

Net total fuel utilisation (%) (166)

Existing multi-fuel firing gas boiler

30–40

50–84

New multi-fuel firing gas boiler (167)

36–42,5

50–84


Table 28

BAT-associated energy efficiency levels (BAT-AEELs) for the combustion of iron and steel process gases in CCGTs

Type of combustion unit

BAT-AEELs (168)  (169)

Net electrical efficiency (%)

Net total fuel utilisation (%) (170)

New unit

Existing unit

CHP CCGT

> 47

40–48

60–82

CCGT

> 47

40–48

No BAT-AEEL

4.2.2.   NOX and CO emissions to air

BAT 47.

In order to prevent or reduce NOX emissions to air from the combustion of iron and steel process gases in boilers, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Low-NOX burners (LNB)

See description in Section 8.3.

Specially designed low-NOX burners in multiple rows per type of fuel or including specific features for multi-fuel firing (e.g. multiple dedicated nozzles for burning different fuels, or including fuels premixing)

Generally applicable

b.

Air staging

See descriptions in Section 8.3

c.

Fuel staging

d.

Flue-gas recirculation

e.

Process gas management system

See description in Section 8.2.

Generally applicable within the constraints associated with the availability of different types of fuel

f.

Advanced control system

See description in Section 8.3.

This technique is used in combination with other techniques

The applicability to old combustion plants may be constrained by the need to retrofit the combustion system and/or control command system

g.

Selective non-catalytic reduction (SNCR)

See descriptions in Section 8.3

Not applicable to combustion plants operated < 500 h/yr

h.

Selective catalytic reduction (SCR)

Not applicable to combustion plants operated < 500 h/yr.

Not generally applicable to combustion plants of < 100 MWth.

Retrofitting existing combustion plants may be constrained by the availability of sufficient space and by the combustion plant configuration

BAT 48.

In order to prevent or reduce NOX emissions to air from the combustion of iron and steel process gases in CCGTs, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Process gas management system

See description in Section 8.2

Generally applicable within the constraints associated with the availability of different types of fuel

b.

Advanced control system

See description in Section 8.3.

This technique is used in combination with other techniques

The applicability to old combustion plants may be constrained by the need to retrofit the combustion system and/or control command system

c.

Water/steam addition

See description in Section 8.3.

In dual fuel gas turbines using DLN for the combustion of iron and steel process gases, water/steam addition is generally used when combusting natural gas

The applicability may be limited due to water availability

d.

Dry low-NOX burners(DLN)

See description in Section 8.3.

DLN that combust iron and steel process gases differ from those that combust natural gas only

Applicable within the constraints associated with the reactiveness of iron and steel process gases such as coke oven gas.

The applicability may be limited in the case of turbines where a retrofit package is not available or when water/steam addition systems are installed

e.

Low-NOX burners (LNB)

See description in Section 8.3

Only applicable to supplementary firing for heat recovery steam generators (HRSGs) of combined-cycle gas turbine (CCGT) combustion plants

f.

Selective catalytic reduction (SCR)

Retrofitting existing combustion plants may be constrained by the availability of sufficient space

BAT 49.

In order to prevent or reduce CO emissions to air from the combustion of iron and steel process gases, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Combustion optimisation

See descriptions in Section 8.3

Generally applicable

b.

Oxidation catalysts

Only applicable to CCGTs.

The applicability may be limited by lack of space, the load requirements and the sulphur content of the fuel


Table 29

BAT-associated emission levels (BAT-AELs) for NOX emissions to air from the combustion of 100 % iron and steel process gases

Type of combustion plant

O2 reference level (vol-%)

BAT-AELs (mg/Nm3) (171)

Yearly average

Daily average or average over the sampling period

New boiler

3

15–65

22–100

Existing boiler

3

20–100 (172)  (173)

22–110 (172)  (174)  (175)

New CCGT

15

20–35

30–50

Existing CCGT

15

20–50 (172)  (173)

30–55 (175)  (176)

As an indication, the yearly average CO emission levels will generally be:

< 5–100 mg/Nm3 for existing boilers operated ≥ 1 500 h/yr,

< 5–35 mg/Nm3 for new boilers,

< 5–20 mg/Nm3 for existing CCGTs operated ≥ 1 500 h/yr or new CCGTs.

4.2.3.   SOX emissions to air

BAT 50.

In order to prevent or reduce SOX emissions to air from the combustion of iron and steel process gases, BAT is to use a combination of the techniques given below.

Technique

Description

Applicability

a.

Process gas management system and auxiliary fuel choice

See description in Section 8.2.

To the extent allowed by the iron- and steel-works, maximise the use of:

a majority of blast furnace gas with a low sulphur content in the fuel diet,

a combination of fuels with a low averaged sulphur content, e.g. individual process fuels with a very low S content such as:

Blast furnace gas with a sulphur content < 10 mg/Nm3,

coke oven gas with a sulphur content < 300 mg/Nm3,

and auxiliary fuels such as:

natural gas,

liquid fuels with a sulphur content of ≤ 0,4 % (in boilers).

Use of a limited amount of fuels with a higher sulphur content

Generally applicable within the constraints associated with the availability of different types of fuel

b.

Coke oven gas pretreatment at the iron- and steel-works

Use of one of the following techniques:

desulphurisation by absorption systems,

wet oxidative desulphurisation

Only applicable to coke oven gas combustion plants


Table 30

BAT-associated emission levels (BAT-AELs) for SO2 emissions to air from the combustion of 100 % iron and steel process gases

Type of combustion plant

O2 reference level (%)

BAT-AELs for SO2 (mg/Nm3)

Yearly average (177)

Daily average or average over the sampling period (178)

New or existing boiler

3

25–150

50–200 (179)

New or existing CCGT

15

10–45

20–70

4.2.4.   Dust emissions to air

BAT 51.

In order to reduce dust emissions to air from the combustion of iron and steel process gases, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Fuel choice/management

Use of a combination of process gases and auxiliary fuels with a low averaged dust or ash content

Generally applicable within the constraints associated with the availability of different types of fuel

b.

Blast furnace gas pretreatment at the iron- and steel-works

Use of one or a combination of dry dedusting devices (e.g. deflectors, dust catchers, cyclones, electrostatic precipitators) and/or subsequent dust abatement (venturi scrubbers, hurdle-type scrubbers, annular gap scrubbers, wet electrostatic precipitators, disintegrators)

Only applicable if blast furnace gas is combusted

c.

Basic oxygen furnace gas pretreatment at the iron- and steel-works

Use of dry (e.g. ESP or bag filter) or wet (e.g. wet ESP or scrubber) dedusting. Further descriptions are given in the Iron and Steel BREF

Only applicable if basic oxygen furnace gas is combusted

d.

Electrostatic precipitator (ESP)

See descriptions in Section 8.5

Only applicable to combustion plants combusting a significant proportion of auxiliary fuels with a high ash content

e.

Bag filter


Table 31

BAT-associated emission levels (BAT-AELs) for dust emissions to air from the combustion of 100 % iron and steel process gases

Type of combustion plant

BAT-AELs for dust (mg/Nm3)

Yearly average (180)

Daily average or average over the sampling period (181)

New or existing boiler

2–7

2–10

New or existing CCGT

2–5

2–5

4.3.   BAT conclusions for the combustion of gaseous and/or liquid fuels on offshore platforms

Unless otherwise stated, the BAT conclusions presented in this section are generally applicable to the combustion of gaseous and/or liquid fuels on offshore platforms. They apply in addition to the general BAT conclusions given in Section 1.

BAT 52.

In order to improve the general environmental performance of the combustion of gaseous and/or liquid fuels on offshore platforms, BAT is to use one or a combination of the techniques given below.

Techniques

Description

Applicability

a.

Process optimisation

Optimise the process in order to minimise the mechanical power requirements

Generally applicable

b.

Control pressure losses

Optimise and maintain inlet and exhaust systems in a way that keeps the pressure losses as low as possible

c.

Load control

Operate multiple generator or compressor sets at load points which minimise emissions

d.

Minimise the ‘spinning reserve’

When running with spinning reserve for operational reliability reasons, the number of additional turbines is minimised, except in exceptional circumstances

e.

Fuel choice

Provide a fuel gas supply from a point in the topside oil and gas process which offers a minimum range of fuel gas combustion parameters, e.g. calorific value, and minimum concentrations of sulphurous compounds to minimise SO2 formation. For liquid distillate fuels, preference is given to low-sulphur fuels

f.

Injection timing

Optimise injection timing in engines

g.

Heat recovery

Utilisation of gas turbine/engine exhaust heat for platform heating purposes

Generally applicable to new combustion plants.

In existing combustion plants, the applicability may be restricted by the level of heat demand and the combustion plant layout (space)

h.

Power integration of multiple gas fields/oilfields

Use of a central power source to supply a number of participating platforms located at different gas fields/oilfields

The applicability may be limited depending on the location of the different gas fields/oilfields and on the organisation of the different participating platforms, including alignment of time schedules regarding planning, start-up and cessation of production

BAT 53.

In order to prevent or reduce NOX emissions to air from the combustion of gaseous and/or liquid fuels on offshore platforms, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Advanced control system

See descriptions in Section 8.3

The applicability to old combustion plants may be constrained by the need to retrofit the combustion system and/or control command system

b.

Dry low-NOX burners (DLN)

Applicable to new gas turbines (standard equipment) within the constraints associated with fuel quality variations.

The applicability may be limited for existing gas turbines by: availability of a retrofit package (for low-load operation), complexity of the platform organisation and space availability

c.

Lean-burn concept

Only applicable to new gas-fired engines

d.

Low-NOX burners (LNB)

Only applicable to boilers

BAT 54.

In order to prevent or reduce CO emissions to air from the combustion of gaseous and/or liquid fuels in gas turbines on offshore platforms, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Combustion optimisation

See descriptions in Section 8.3

Generally applicable

b.

Oxidation catalysts

Not applicable to combustion plants operated < 500 h/yr.

Retrofitting existing combustion plants may be constrained by the availability of sufficient space and by weight restrictions


Table 32

BAT-associated emission levels (BAT-AELs) for NOX emissions to air from the combustion of gaseous fuels in open-cycle gas turbines on offshore platforms

Type of combustion plant

BAT-AELs (mg/Nm3) (182)

Average over the sampling period

New gas turbine combusting gaseous fuels (183)

15–50 (184)

Existing gas turbine combusting gaseous fuels (183)

< 50–350 (185)

As an indication, the average CO emission levels over the sampling period will generally be:

< 100 mg/Nm3 for existing gas turbines combusting gaseous fuels on offshore platforms operated ≥ 1 500 h/yr,

< 75 mg/Nm3 for new gas turbines combusting gaseous fuels on offshore platforms.

5.   BAT CONCLUSIONS FOR MULTI-FUEL-FIRED PLANTS

5.1.   BAT conclusions for the combustion of process fuels from the chemical industry

Unless otherwise stated, the BAT conclusions presented in this section are generally applicable to the combustion of process fuels from the chemical industry, individually, in combination, or simultaneously with other gaseous and/or liquid fuels. They apply in addition to the general BAT conclusions given in Section 1.

5.1.1.   General environmental performance

BAT 55.

In order to improve the general environmental performance of the combustion of process fuels from the chemical industry in boilers, BAT is to use an appropriate combination of the techniques given in BAT 6 and below.

Technique

Description

Applicability

a.

Pretreatment of process fuel from the chemical industry

Perform fuel pretreatment on and/or off the site of the combustion plant to improve the environmental performance of fuel combustion

Applicable within the constraints associated with process fuel characteristics and space availability

5.1.2.   Energy efficiency

Table 33

BAT-associated energy efficiency levels (BAT-AEELs) for the combustion of process fuels from the chemical industry in boilers

Type of combustion unit

BAT-AEELs (186)  (187)

Net electrical efficiency (%)

Net total fuel utilisation (%) (188)  (189)

New unit

Existing unit

New unit

Existing unit

Boiler using liquid process fuels from the chemical industry, including when mixed with HFO, gas oil and/or other liquid fuels

> 36,4

35,6–37,4

80–96

80–96

Boiler using gaseous process fuels from the chemical industry, including when mixed with natural gas and/or other gaseous fuels

39–42,5

38–40

78–95

78–95

5.1.3.   NOX and CO emissions to air

BAT 56.

In order to prevent or reduce NOX emissions to air while limiting CO emissions to air from the combustion of process fuels from the chemical industry, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Low-NOX burners (LNB)

See descriptions in Section 8.3

Generally applicable

b.

Air staging

c.

Fuel staging

See description in Section 8.3.

Applying fuel staging when using liquid fuel mixtures may require a specific burner design

d.

Flue-gas recirculation

See descriptions in Section 8.3

Generally applicable to new combustion plants.

Applicable to existing combustion plants within the constraints associated with chemical installation safety

e.

Water/steam addition

The applicability may be limited due to water availability

f.

Fuel choice

Applicable within the constraints associated with the availability of different types of fuel and/or an alternative use of the process fuel

g.

Advanced control system

The applicability to old combustion plants may be constrained by the need to retrofit the combustion system and/or control command system

h.

Selective non-catalytic reduction (SNCR)

Applicable to existing combustion plants within the constraints associated with chemical installation safety.

Not applicable to combustion plants operated < 500 h/yr.

The applicability may be limited in the case of combustion plants operated between 500 h/yr and 1 500  h/yr with frequent fuel changes and frequent load variations

i.

Selective catalytic reduction (SCR)

Applicable to existing combustion plants within the constraints associated with duct configuration, space availability and chemical installation safety.

Not applicable to combustion plants operated < 500 h/yr.

There may be technical and economic restrictions for retrofitting existing combustion plants operated between 500 h/yr and 1 500  h/yr.

Not generally applicable to combustion plants of < 100 MWth


Table 34

BAT-associated emission levels (BAT-AELs) for NOX emissions to air from the combustion of 100 % process fuels from the chemical industry in boilers

Fuel phase used in the combustion plant

BAT-AELs (mg/Nm3)

Yearly average

Daily average or average over the sampling period

New plant

Existing plant (190)

New plant

Existing plant (191)

Mixture of gases and liquids

30–85

80–290 (192)

50–110

100–330 (192)

Gases only

20–80

70–100 (193)

30–100

85–110 (194)

As an indication, the yearly average CO emission levels for existing plants operated ≥ 1 500 h/yr and for new plants will generally be < 5–30 mg/Nm3.

5.1.4.   SOX, HCl and HF emissions to air

BAT 57.

In order to reduce SOX, HCl and HF emissions to air from the combustion of process fuels from the chemical industry in boilers, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Fuel choice

See descriptions in Section 8.4

Applicable within the constraints associated with the availability of different types of fuel and/or an alternative use of the process fuel

b.

Boiler sorbent injection (in-furnace or in-bed)

Applicable to existing combustion plants within the constraints associated with duct configuration, space availability and chemical installation safety.

Wet FGD and seawater FGD are not applicable to combustion plants operated < 500 h/yr.

There may be technical and economic restrictions for applying wet FGD or seawater FGD to combustion plants of < 300 MWth, and for retrofitting combustion plants operated between 500 h/yr and 1 500  h/yr with wet FGD or seawater FGD

c.

Duct sorbent injection (DSI)

d.

Spray dry absorber (SDA)

e.

Wet scrubbing

See description in Section 8.4.

Wet scrubbing is used to remove HCl and HF when no wet FGD is used to reduce SOX emissions

f.

Wet flue-gas desulphurisation (wet FGD)

See descriptions in Section 8.4

g.

Seawater FGD


Table 35

BAT-associated emission levels (BAT-AELs) for SO2 emissions to air from the combustion of 100 % process fuels from the chemical industry in boilers

Type of combustion plant

BAT-AELs (mg/Nm3)

Yearly average (195)

Daily average or average over the sampling period (196)

New and existing boilers

10–110

90–200


Table 36

BAT-associated emission levels (BAT-AELs) for HCl and HF emissions to air from the combustion of process fuels from the chemical industry in boilers

Combustion plant total rated thermal input

(MWth)

BAT-AELs (mg/Nm3)

HCl

HF

Average of samples obtained during one year

New plant

Existing plant (197)

New plant

Existing plant (197)

< 100

1–7

2–15 (198)

< 1–3

< 1–6 (199)

≥ 100

1–5

1–9 (198)

< 1–2

< 1–3 (199)

5.1.5.   Dust and particulate-bound metal emissions to air

BAT 58.

In order to reduce emissions to air of dust, particulate-bound metals, and trace species from the combustion of process fuels from the chemical industry in boilers, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Electrostatic precipitator (ESP)

See descriptions in Section 8.5

Generally applicable

b.

Bag filter

c.

Fuel choice

See description in Section 8.5.

Use of a combination of process fuels from the chemical industry and auxiliary fuels with a low averaged dust or ash content

Applicable within the constraints associated with the availability of different types of fuel and/or an alternative use of the process fuel

d.

Dry or semi-dry FGD system

See descriptions in Section 8.5.

The technique is mainly used for SOX, HCl and/or HF control

See applicability in BAT 57

e.

Wet flue-gas desulphurisation (wet FGD)


Table 37

BAT-associated emission levels (BAT-AELs) for dust emissions to air from the combustion of mixtures of gases and liquids composed of 100 % process fuels from the chemical industry in boilers

Combustion plant total rated thermal input

(MWth)

BAT-AELs for dust (mg/Nm3)

Yearly average

Daily average or average over the sampling period

New plant

Existing plant (200)

New plant

Existing plant (201)

< 300

2–5

2–15

2–10

2–22 (202)

≥ 300

2–5

2–10 (203)

2–10

2–11 (202)

5.1.6.   Emissions of volatile organic compounds and polychlorinated dibenzo-dioxins and -furans to air

BAT 59.

In order to reduce emissions to air of volatile organic compounds and polychlorinated dibenzo-dioxins and -furans from the combustion of process fuels from the chemical industry in boilers, BAT is to use one or a combination of the techniques given in BAT 6 and below.

Technique

Description

Applicability

a.

Activated carbon injection

See description in Section 8.5

Only applicable to combustion plants using fuels derived from chemical processes involving chlorinated substances.

For the applicability of SCR and rapid quenching see BAT 56 and BAT 57

b.

Rapid quenching using wet scrubbing/flue-gas condenser

See description of wet scrubbing/flue-gas codenser in Section 8.4

c.

Selective catalytic reduction (SCR)

See description in Section 8.3.

The SCR system is adapted and larger than an SCR system only used for NOX reduction


Table 38

BAT-associated emission levels (BAT-AELs) for PCDD/F and TVOC emissions to air from the combustion of 100 % process fuels from the chemical industry in boilers

Pollutant

Unit

BAT-AELs

Average over the sampling period

PCDD/F (204)

ng I-TEQ/Nm3

< 0,012–0,036

TVOC

mg/Nm3

0,6–12

6.   BAT CONCLUSIONS FOR THE CO-INCINERATION OF WASTE

Unless otherwise stated, the BAT conclusions presented in this section are generally applicable to the co-incineration of waste in combustion plants. They apply in addition to the general BAT conclusions given in Section 1.

When waste is co-incinerated, the BAT-AELs in this section apply to the entire flue-gas volume generated.

In addition, when waste is co-incinerated together with the fuels covered by Section 2, the BAT-AELs set out in Section 2 also apply (i) to the entire flue-gas volume generated, and (ii) to the flue-gas volume resulting from the combustion of the fuels covered by that section using the mixing rule formula of Annex VI (part 4) to Directive 2010/75/EU, in which the BAT-AELs for the flue-gas volume resulting from the combustion of waste are to be determined on the basis of BAT 61.

6.1.1.   General environmental performance

BAT 60.

In order to improve the general environmental performance of the co-incineration of waste in combustion plants, to ensure stable combustion conditions, and to reduce emissions to air, BAT is to use technique BAT 60 (a) below and a combination of the techniques given in BAT 6 and/or the other techniques below.

Technique

Description

Applicability

a.

Waste pre-acceptance and acceptance

Implement a procedure for receiving any waste at the combustion plant according to the corresponding BAT from the Waste Treatment BREF. Acceptance criteria are set for critical parameters such as heating value, and the content of water, ash, chlorine and fluorine, sulphur, nitrogen, PCB, metals (volatile (e.g. Hg, Tl, Pb, Co, Se) and non-volatile (e.g. V, Cu, Cd, Cr, Ni)), phosphorus and alkali (when using animal by-products).

Apply quality assurance systems for each waste load to guarantee the characteristics of the wastes co-incinerated and to control the values of defined critical parameters (e.g. EN 15358 for non-hazardous solid recovered fuel)

Generally applicable

b.

Waste selection/limitation

Careful selection of waste type and mass flow, together with limiting the percentage of the most polluted waste that can be co-incinerated. Limit the proportion of ash, sulphur, fluorine, mercury and/or chlorine in the waste entering the combustion plant.

Limitation of the amount of waste to be co-incinerated

Applicable within the constraints associated with the waste management policy of the Member State

c.

Waste mixing with the main fuel

Effective mixing of waste and the main fuel, as a heterogeneous or poorly mixed fuel stream or an uneven distribution may influence the ignition and combustion in the boiler and should be prevented

Mixing is only possible when the grinding behaviour of the main fuel and waste is similar or when the amount of waste is very small compared to the main fuel

d.

Waste drying

Pre-drying of the waste before introducing it into the combustion chamber, with a view to maintaining the high performance of the boiler

The applicability may be limited by insufficient recoverable heat from the process, by the required combustion conditions, or by the waste moisture content

e.

Waste pretreatment

See techniques described in the Waste Treatment and Waste Incineration BREFs, including milling, pyrolysis and gasification

See applicability in the Waste Treatment BREF and in the Waste incineration BREF

BAT 61.

In order to prevent increased emissions from the co-incineration of waste in combustion plants, BAT is to take appropriate measures to ensure that the emissions of polluting substances in the part of the flue-gases resulting from waste co-incineration are not higher than those resulting from the application of BAT conclusions for the incineration of waste.

BAT 62.

In order to minimise the impact on residues recycling of the co-incineration of waste in combustion plants, BAT is to maintain a good quality of gypsum, ashes and slags as well as other residues, in line with the requirements set for their recycling when the plant is not co-incinerating waste, by using one or a combination of the techniques given in BAT 60 and/or by restricting the co-incineration to waste fractions with pollutant concentrations similar to those in other combusted fuels.

6.1.2.   Energy efficiency

BAT 63.

In order to increase the energy efficiency of the co-incineration of waste, BAT is to use an appropriate combination of the techniques given in BAT 12 and BAT 19, depending on the main fuel type used and on the plant configuration.

The BAT-associated energy efficiency levels (BAT-AEELs) are given in Table 8 for the co-incineration of waste with biomass and/or peat and in Table 2 for the co-incineration of waste with coal and/or lignite.

6.1.3.   NOX and CO emissions to air

BAT 64.

In order to prevent or reduce NOX emissions to air while limiting CO and N2O emissions from the co-incineration of waste with coal and/or lignite, BAT is to use one or a combination of the techniques given in BAT 20.

BAT 65.

In order to prevent or reduce NOX emissions to air while limiting CO and N2O emissions from the co-incineration of waste with biomass and/or peat, BAT is to use one or a combination of the techniques given in BAT 24.

6.1.4.   SOX, HCl and HF emissions to air

BAT 66.

In order to prevent or reduce SOX, HCl and HF emissions to air from the co-incineration of waste with coal and/or lignite, BAT is to use one or a combination of the techniques given in BAT 21.

BAT 67.

In order to prevent or reduce SOX, HCl and HF emissions to air from the co-incineration of waste with biomass and/or peat, BAT is to use one or a combination of the techniques given in BAT 25.

6.1.5.   Dust and particulate-bound metal emissions to air

BAT 68.

In order to reduce dust and particulate-bound metal emissions to air from the co-incineration of waste with coal and/or lignite, BAT is to use one or a combination of the techniques given in BAT 22.

Table 39

BAT-associated emission levels (BAT-AELs) for metal emissions to air from the co-incineration of waste with coal and/or lignite

Combustion plant total rated thermal input (MWth)

BAT-AELs

Averaging period

Sb + As + Pb + Cr + Co + Cu + Mn + Ni + V (mg/Nm3)

Cd + Tl (μg/Nm3)

< 300

0,005–0,5

5–12

Average over the sampling period

≥ 300

0,005–0,2

5–6

Average of samples obtained during one year

BAT 69.

In order to reduce dust and particulate-bound metal emissions to air from the co-incineration of waste with biomass and/or peat, BAT is to use one or a combination of the techniques given in BAT 26.

Table 40

BAT-associated emission levels (BAT-AELs) for metal emissions to air from the co-incineration of waste with biomass and/or peat

BAT-AELs

(average of samples obtained during one year)

Sb + As + Pb + Cr + Co + Cu + Mn + Ni + V (mg/Nm3)

Cd+Tl (μg/Nm3)

0,075–0,3

< 5

6.1.6.   Mercury emissions to air

BAT 70.

In order to reduce mercury emissions to air from the co-incineration of waste with biomass, peat, coal and/or lignite, BAT is to use one or a combination of the techniques given in BAT 23 and BAT 27.

6.1.7.   Emissions of volatile organic compounds and polychlorinated dibenzo-dioxins and -furans to air

BAT 71.

In order to reduce emissions of volatile organic compounds and polychlorinated dibenzo-dioxins and -furans to air from the co-incineration of waste with biomass, peat, coal and/or lignite, BAT is to use a combination of the techniques given in BAT 6, BAT 26 and below.

Technique

Description

Applicability

a.

Activated carbon injection

See description in Section 8.5.

This process is based on the adsorption of pollutant molecules by the activated carbon

Generally applicable

b.

Rapid quenching using wet scrubbing/flue-gas condenser

See description of wet scrubbing/flue-gas condenser in Section 8.4

c.

Selective catalytic reduction (SCR)

See description in Section 8.3.

The SCR system is adapted and larger than an SCR system only used for NOX reduction

See applicability in BAT 20 and in BAT 24


Table 41

BAT-associated emission levels (BAT-AELs) for PCDD/F and TVOC emissions to air from the co-incineration of waste with biomass, peat, coal and/or lignite

Type of combustion plant

BAT-AELs

PCDD/F (ng I-TEQ/Nm3)

TVOC (mg/Nm3)

Average over the sampling period

Yearly average

Daily average

Biomass-, peat-, coal- and/or lignite-fired combustion plant

< 0,01–0,03

< 0,1–5

0,5–10

7.   BAT CONCLUSIONS FOR GASIFICATION

Unless otherwise stated, the BAT conclusions presented in this section are generally applicable to all gasification plants directly associated to combustion plants, and to IGCC plants. They apply in addition to the general BAT conclusions given in Section 1.

7.1.1.   Energy efficiency

BAT 72.

In order to increase the energy efficiency of IGCC and gasification units, BAT is to use one or a combination of the techniques given in BAT 12 and below.

Technique

Description

Applicability

a.

Heat recovery from the gasification process

As the syngas needs to be cooled down to be cleaned further, energy can be recovered for producing additional steam to be added to the steam turbine cycle, enabling additional electrical power to be produced

Only applicable to IGCC units and to gasification units directly associated to boilers with syngas pretreatment that requires cooling down of the syngas

b.

Integration of gasification and combustion processes

The unit can be designed with full integration of the air supply unit (ASU) and the gas turbine, with all the air fed to the ASU being supplied (extracted) from the gas turbine compressor

The applicability is limited to IGCC units by the flexibility needs of the integrated plant to quickly provide the grid with electricity when renewable power plants are not available

c.

Dry feedstock feeding system

Use of a dry system for feeding the fuel to the gasifier, in order to improve the energy efficiency of the gasification process

Only applicable to new units

d.

High-temperature and -pressure gasification

Use of gasification technique with high-temperature and -pressure operating parameters, in order to maximise the efficiency of energy conversion

Only applicable to new units

e.

Design improvements

Design improvements, such as:

modifications of the gasifier refractory and/or cooling system,

installation of an expander to recover energy from the syngas pressure drop before combustion

Generally applicable to IGCC units


Table 42

BAT-associated energy efficiency levels (BAT-AEELs) for gasification and IGCC units

Type of combustion unit configuration

BAT-AEELs

Net electrical efficiency (%) of an IGCC unit

Net total fuel utilisation (%) of a new or existing gasification unit

New unit

Existing unit

Gasification unit directly associated to a boiler without prior syngas treatment

No BAT-AEEL

> 98

Gasification unit directly associated to a boiler with prior syngas treatment

No BAT-AEEL

> 91

IGCC unit

No BAT-AEEL

34–46

> 91

7.1.2.   NOX and CO emissions to air

BAT 73.

In order to prevent and/or reduce NOX emissions to air while limiting CO emissions to air from IGCC plants, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Combustion optimisation

See description in Section 8.3

Generally applicable

b.

Water/steam addition

See description in Section 8.3.

Some intermediate-pressure steam from the steam turbine is reused for this purpose

Only applicable to the gas turbine part of the IGCC plant.

The applicability may be limited due to water availability

c.

Dry low-NOX burners (DLN)

See description in Section 8.3

Only applicable to the gas turbine part of the IGCC plant.

Generally applicable to new IGCC plants.

Applicable on a case-by-case basis for existing IGCC plants, depending on the availability of a retrofit package. Not applicable for syngas with a hydrogen content of > 15 %

d.

Syngas dilution with waste nitrogen from the air supply unit (ASU)

The ASU separates the oxygen from the nitrogen in the air, in order to supply high-quality oxygen to the gasifier. The waste nitrogen from the ASU is reused to reduce the combustion temperature in the gas turbine, by being premixed with the syngas before combustion

Only applicable when an ASU is used for the gasification process

e.

Selective catalytic reduction (SCR)

See description in Section 8.3

Not applicable to IGCC plants operated < 500 h/yr.

Retrofitting existing IGCC plants may be constrained by the availability of sufficient space.

There may be technical and economic restrictions for retrofitting existing IGCC plants operated between 500 h/yr and 1 500  h/yr


Table 43

BAT-associated emission levels (BAT-AELs) for NOX emissions to air from IGCC plants

IGCC plant total rated thermal input

(MWth)

BAT-AELs (mg/Nm3)

Yearly average

Daily average or average over the sampling period

New plant

Existing plant

New plant

Existing plant

≥ 100

10–25

12–45

1–35

1–60

As an indication, the yearly average CO emission levels for existing plants operated ≥ 1 500 h/yr and for new plants will generally be < 5–30 mg/Nm3.

7.1.3.   SOX emissions to air

BAT 74.

In order to reduce SOX emissions to air from IGCC plants, BAT is to use the technique given below.

Technique

Description

Applicability

a.

Acid gas removal

Sulphur compounds from the feedstock of a gasification process are removed from the syngas via acid gas removal, e.g. including a COS (and HCN) hydrolysis reactor and the absorption of H2S using a solvent such as methyl diethanolamine. Sulphur is then recovered as either liquid or solid elemental sulphur (e.g. through a Claus unit), or as sulphuric acid, depending on market demands

The applicability may be limited in the case of biomass IGCC plants due to the very low sulphur content in biomass

The BAT-associated emission level (BAT-AEL) for SO2 emissions to air from IGCC plants of ≥ 100 MWth is 3–16 mg/Nm3, expressed as a yearly average.

7.1.4.   Dust, particulate-bound metal, ammonia and halogen emissions to air

BAT 75.

In order to prevent or reduce dust, particulate-bound metal, ammonia and halogen emissions to air from IGCC plants, BAT is to use one or a combination of the techniques given below.

Technique

Description

Applicability

a.

Syngas filtration

Dedusting using fly ash cyclones, bag filters, ESPs and/or candle filters to remove fly ash and unconverted carbon. Bag filters and ESPs are used in the case of syngas temperatures up to 400 °C

Generally applicable

b.

Syngas tars and ashes recirculation to the gasifier

Tars and ashes with a high carbon content generated in the raw syngas are separated in cyclones and recirculated to the gasifier, in the case of a low syngas temperature at the gasifier outlet (< 1 100  °C)

c.

Syngas washing

Syngas passes through a water scrubber, downstream of other dedusting technique(s), where chlorides, ammonia, particles and halides are separated


Table 44

BAT-associated emission levels (BAT-AELs) for dust and particulate-bound metal emissions to air from IGCC plants

IGCC plant total rated thermal input

(MWth)

BAT-AELs

Sb + As + Pb + Cr + Co + Cu + Mn + Ni + V (mg/Nm3)

(Average over the sampling period)

Hg (μg/Nm3)

(Average over the sampling period)

Dust (mg/Nm3)

(yearly average)

≥ 100

< 0,025

< 1

< 2,5

8.   DESCRIPTION OF TECHNIQUES

8.1.   General techniques

Technique

Description

Advanced control system

The use of a computer-based automatic system to control the combustion efficiency and support the prevention and/or reduction of emissions. This also includes the use of high-performance monitoring.

Combustion optimisation

Measures taken to maximise the efficiency of energy conversion, e.g. in the furnace/boiler, while minimising emissions (in particular of CO). This is achieved by a combination of techniques including good design of the combustion equipment, optimisation of the temperature (e.g. efficient mixing of the fuel and combustion air) and residence time in the combustion zone, and use of an advanced control system.

8.2.   Techniques to increase energy efficiency

Technique

Description

Advanced control system

See Section 8.1

CHP readiness

The measures taken to allow the later export of a useful quantity of heat to an off-site heat load in a way that will achieve at least a 10 % reduction in primary energy usage compared to the separate generation of the heat and power produced. This includes identifying and retaining access to specific points in the steam system from which steam can be extracted, as well as making sufficient space available to allow the later fitting of items such as pipework, heat exchangers, extra water demineralisation capacity, standby boiler plant and back-pressure turbines. Balance of Plant (BoP) systems and control/instrumentation systems are suitable for upgrade. Later connection of back-pressure turbine(s) is also possible.

Combined cycle

Combination of two or more thermodynamic cycles, e.g. a Brayton cycle (gas turbine/combustion engine) with a Rankine cycle (steam turbine/boiler), to convert heat loss from the flue-gas of the first cycle to useful energy by subsequent cycle(s).

Combustion optimisation

See Section 8.1

Flue-gas condenser

A heat exchanger where water is preheated by the flue-gas before it is heated in the steam condenser. The vapour content in the flue-gas thus condenses as it is cooled by the heating water. The flue-gas condenser is used both to increase the energy efficiency of the combustion unit and to remove pollutants such as dust, SOX, HCl, and HF from the flue-gas.

Process gas management system

A system that enables the iron and steel process gases that can be used as fuels (e.g. blast furnace, coke oven, basic oxygen furnace gases) to be directed to the combustion plants, depending on the availability of these fuels and on the type of combustion plants in an integrated steelworks.

Supercri