‘ANNEX XIII

Activity-specific guidelines for determination of nitrous oxide (N2O) emissions from nitric acid, adipic acid, caprolactam, glyoxal and glyoxylic acid production

1.   BOUNDARIES AND COMPLETENESS

The activity-specific guidelines contained in this Annex shall apply to monitoring N2O emissions occurring from the production of nitric acid, adipic acid, caprolactam, glyoxal and glyoxylic acid within relevant installations included pursuant to Article 24 of Directive 2003/87/EC.

For each activity from which N2O emissions result, all sources emitting N2O from production processes shall be covered, including where N2O emissions from production are channelled through any abatement equipment. This includes:

—	nitric acid production — N2O emissions from the catalytic oxidation of ammonia and/or from the NOx/N2O abatement units,

—	adipic acid production — N2O emissions, including from the oxidation reaction, any direct process venting and/or any emissions control equipment,

—	glyoxal and glyoxylic acid production — N2O emissions, including from the process reactions, any direct process venting and/or any emissions control equipment,

—	caprolactam production — N2O emissions, including from the process reactions, any direct process venting and/or any emissions control equipment.

These provisions are not applicable to any N2O emissions from combustion of fuels.

Any relevant CO2 emissions directly associated with the production process (and not already covered under the EU ETS) that are included in the installation’s greenhouse gas emission permit shall be monitored and reported in accordance with these guidelines.

Annex I, Section 16 does not apply to the monitoring of N2O emissions.

2.   DETERMINATION OF CO2(e) AND N2O EMISSIONS

2.1.   ANNUAL N2O EMISSIONS

Emissions of N2O from nitric acid production shall be measured using continuous emissions measurement (excluding for de minimis sources — Section 6.3).

Emissions of N2O from adipic acid, caprolactam, glyoxal and glyoxylic acid production shall be monitored using continuous emissions measurement for abated emissions and the calculation method (based on a mass balance approach (Section 2.6)) for temporary occurrences of unabated emissions.

Total annual N2O emissions from the installation are the sum of annual N2O emissions from all its emission sources.

For each emission source where continuous emissions measurement is applied, the total annual emissions are the sum of all hourly emissions using the following formula:

Where:

N2O emissionsannual	=	total annual emissions of N2O from the emission source in tonnes N2O
N2O conc hourly	=	hourly concentrations of N2O in mg/Nm3 in the flue gas flow measured during operation
Flue gas flow	=	flue gas flow as calculated below in Nm3/h for each hourly concentration

2.2.   HOURLY N2O EMISSIONS

Annual average hourly N2O emissions for each source where continuous emission measurement is applied shall be calculated using the following equation:

Where:

N2O emissionsav hourly	=	annual average hourly N2O emissions in kg/h from the source
N2O conc hourly	=	hourly concentrations of N2O in mg/Nm3 in the flue gas flow measured during operation
Flue gas flow	=	flue gas flow as calculated below in Nm3/h for each hourly concentration

The total uncertainty of the annual hourly average emissions for each emission source must not exceed the tier values as set out below. The highest tier approach shall be used by all operators. Only if it is shown to the satisfaction of the competent authority that the highest tier is not technically feasible or will lead to unreasonably high costs, may a next lower tier be used. For the reporting period 2008–12 as a minimum Tier 2 shall be applied unless technically not feasible.

In cases for which it is technically not feasible or would lead to unreasonable costs to apply at least Tier 1 requirements for each emission source (except de minimis sources), the operator shall apply and demonstrate compliance with the appropriate tier for the total annual emission for the emission source as in Section 2, Annex XII. For the reporting period 2008–12 the minimum requirement is Tier 2, unless technically not feasible. Respective installations applying this approach are to be notified by Member States to the Commission pursuant to Article 21 of Directive 2003/87/EC.

Tier 1:

For each emission source a total uncertainty of annual average hourly emissions of less than ± 10 % shall be achieved.

Tier 2:

For each emission source a total uncertainty of annual average hourly emissions of less than ± 7,5 % shall be achieved.

Tier 3:

For each emission source a total uncertainty of annual average hourly emissions of less than ± 5 % shall be achieved.

2.3.   HOURLY N2O CONCENTRATIONS

Hourly N2O concentrations [mg/Nm3] in the flue gas from each emission source shall be determined by continuous measurement at a representative point, after the NOx/N2O abatement equipment (if abatement is used).

Suitable measuring techniques include IR Spectroscopy, but others can be used in accordance with paragraph 2 of Section 6.1 of Annex I, provided they achieve the required uncertainty level for the N2O emissions. The used techniques must be capable of measuring N2O concentrations of all emission sources during both abated and unabated conditions (for example during periods when abatement equipment fails and concentrations increase). If uncertainties increase during such periods, these must be taken into account in the uncertainty assessment.

All measurements shall be adjusted to a dry gas basis and be reported consistently.

2.4.   DETERMINATION OF FLUE GAS FLOW

The methods for monitoring flue gas flow set out in Annex XII shall be used for measuring flue gas flow for N2O emissions monitoring.

For nitric acid production, Method A shall be applied unless it is not technically feasible, in which case an alternative method, such as a mass balance approach based on significant parameters (such as ammonia input load) or determination of flow by continuous emissions flow measurement, can be used provided it is approved by the competent authority as part of the evaluation of the monitoring plan and the monitoring methodology therein.

For other activities, other methods for monitoring flue gas flow described in Annex XII can be used, provided they are approved by the competent authority as part of the evaluation of the monitoring plan and the monitoring methodology therein.

Method A — nitric acid production

The flue gas flow shall be calculated in accordance with the following formula:

Where:

Vair	=	total input air flow in Nm3/h at standard conditions;
O2 air	=	volume fraction of O2 in dry air [= 0,2095];
O2 flue gas	=	volume fraction of O2 in flue gas.

The Vair shall be calculated as the sum of all air flows entering the nitric acid production unit.

The installation shall apply the following formula, unless stated otherwise in its monitoring plan:

Vair = Vprim + Vsec + Vseal

Where:

Vprim	=	Primary input air flow in Nm3/h at standard conditions;
Vsec	=	Secondary input air flow in Nm3/h at standard conditions;
Vseal	=	Seal input air flow in Nm3/h at standard conditions.

The Vprim is determined by continuous flow measurement before the mixing with ammonia takes place. The Vsec is determined by continuous flow measurement e.g. before the heat recovery unit. The Vseal is the purged airflow within the nitric acid production process (if relevant).

For input air streams accounting for cumulatively less than 2,5 % of the total air flow, the competent authority may accept estimation methods for determination of this air flow rate proposed by the operator based on industry best practices.

The operator shall provide evidence through measurements under normal operation conditions that the flue gas flow measured is sufficiently homogeneous to allow for the proposed measurement method. If non-homogeneous flow is confirmed through these measurements, this must be taken into account when determining appropriate monitoring methods and when calculating the uncertainty in the N2O emissions.

All measurements shall be adjusted to a dry gas basis and be reported consistently.

2.5.   OXYGEN (O2)

Oxygen concentrations in the flue gas shall be measured if needed for calculating the flue gas flow according to Section 2.4. Requirements described for concentration measurements within Section 6 of Annex I shall apply. Suitable measurement techniques include: paramagnetic alternating pressure, magnetic torsion balance or zirconium dioxide probe. Uncertainty of O2 concentration measurements shall be taken into account in determining the uncertainty in the N2O emissions.

All measurements shall be adjusted to a dry gas basis and be reported consistently.

2.6.   CALCULATION OF N2O EMISSIONS

For specific periodic, unabated emissions of N2O from adipic acid, caprolactam, glyoxal and glyoxylic acid production (such as unabated emissions from venting for safety reasons and/or when abatement plant fails) where continuous emissions monitoring of N2O is not technically feasible, calculation of N2O emissions using a mass balance approach can be applied. The calculation method shall be based on the maximum potential emission rate of N2O from the chemical reaction taking place at the time and the period of the emission. The specific calculation approach shall be approved by the competent authority as part of the evaluation of the monitoring plan and the monitoring methodology therein.

The uncertainty in any calculated emissions for a specific emission source shall be taken into account in determining the annual average hourly uncertainty for the emission source. The same tiers as for emissions measured entirely with continuous emissions measurement shall be applied to calculated emissions, or where a combination of calculation and continuous measurement are used to determine N2O emissions.

3.   CALCULATION OF ANNUAL CO2 EQUIVALENTS (CO2(e))

The total annual N2O emissions from all emissions sources (measured in tonnes to three decimal places) shall be converted to annual CO2(e) emissions (rounded tonnes) using the following formula:

For emissions during the period 2008–12, the Global Warming Potential GWPN2O = 310 t CO2(e)/t N2O shall be used, which is the value provided in the Intergovernmental Panel on Climate Change’s Second Assessment Report (1995 IPCC GWP value).

The total annual CO2(e) generated by all emission sources and any direct CO2 emissions from other emission sources (if included in the greenhouse gas permit) shall be added to the total annual CO2 emissions generated by the installation and shall be used for reporting and surrendering allowances.

4.   DETERMINATION OF ACTIVITY PRODUCTION RATES

Production rates shall be calculated using daily production reports and hours of operation.

5.   MONITORING PLAN

In addition to requirements set out in Annex I, Section 4.3(a), (b), (c), (d), (j), (k), (m) and (n), monitoring plans for installations covered by this Annex shall contain the following information:

(a)	all relevant emissions points during typical operation, and during restrictive and transition phases (e.g. breakdown periods or commissioning phases) shown in a process diagram;

(b)	the method and parameters used to determine the quantity of materials (e.g. ammonia) used in the production process and the maximum quantity of material used at full capacity;

(c)	the method and parameters used to determine the quantity of product produced as an hourly load, expressed as nitric acid (100 %), adipic acid (100 %), glyoxal and glyoxylic acid and caprolactam per hour respectively;

(d)	the method and parameters used to determine the N2O concentration in the flue gas from each emission source, its operating range, and its uncertainty, and details of any alternative methods to be applied if concentrations fall outside the operating range and the situations when this may occur;

(e)	the method used to determine the total flue gas flow rate (expressed in Nm3 per hour) from each emission source, its operating range and its uncertainty. If derived by calculation, details for each monitored flue gas stream shall be given;

(f)	the calculation method used to determine N2O emissions from periodic, unabated sources in adipic acid, caprolactam, glyoxal and glyoxylic acid production;

(g)	the way in which or the extent to which the installation operates with variable loads, and the manner in which the operational management is carried out;

(h)	the method and any calculation formulae used to determine the annual N2O emissions of each emission source;

(i)	the process conditions that deviate from normal operations, an indication of the potential frequency and the duration of such conditions, as well as an indication of the volume of the N2O emissions during the deviating process conditions (such as abatement equipment malfunction);

(j)	the assessment used to show that the tier uncertainty requirements referred in Section 2 of this Annex are complied with and the tier achieved;

(k)	the value expressed in kg/N2O per hour which has been determined in accordance with Annex I, Sections 6.3(a) and (b) in order to be used in case the measuring instrument fails or does not function properly;

(l)	Details of any deviations from the requirements of general standards such as EN 14181 and ISO 14956:2002.

In addition to the requirements in Annex I, Section 4.3, a substantial change to the monitoring methodology as part of the monitoring plan shall be subject to the approval of the competent authority if it concerns:

—	significant changes in the functioning of the installation that affect the total level of N2O emissions, the N2O concentration, the flow rate or other parameters of the flue gas, especially if N2O abatement measures are installed or replaced,

—	changes in the methods used to determine N2O emissions, including changes in the continuous measurement of concentrations, oxygen concentrations and flue gas flow, or calculation method which significantly affect the total uncertainty of the emissions,

—	changes in the parameters used to determine annual emissions and/or production of nitric acid, adipic acid, caprolactam, glyoxal and glyoxylic acid,

—	changes in uncertainty assessment.

6.   GENERAL

6.1.   SAMPLING RATES

Valid hourly averages shall be calculated in accordance with Section 6.3(a) of Annex I for:

—	concentration of N2O in the flue gas,

—	total flue gas flow where this is measured directly and where required,

—	all gas flows and oxygen concentrations necessary to determine the total flue gas flow indirectly.

6.2.   MISSING DATA

Missing data shall be dealt with in accordance with Annex I, Section 6.3(a) and (b). If missing data occur during failure of abatement equipment, it shall be assumed that emissions for that whole hour were unabated and substitute values calculated accordingly.

The operator shall take all practical steps to ensure that continuous emissions monitoring equipment is not out of operation for more than one week in any calendar year. If this occurs, the operator shall inform the competent authority immediately.

6.3.   DE MINIMIS SOURCES OF N2O

‘ De minimis source streams’ for N2O emission sources means one or more minor, unabated source streams selected by the operator and jointly emitting 1 000 tonnes of CO2(e) or less per year, or that emit less that 20 000 tonnes of CO2(e) per year and contribute less than 2 % of the total annual emissions of CO2(e) of that installation.

Subject to approval by the competent authority, the operator may apply approaches for monitoring and reporting using his own no-tier estimation method for de minimis source streams of N2O.

6.4.   CORROBORATING CALCULATION OF EMISSIONS

Annex I, Section 6.3(c) shall apply to corroborating reported emissions of N2O (from continuous emissions measurement and calculation) and performed using production data, the 2006 IPCC Guidelines and the approach specified in Annex I, Section 10.3.3 “Horizontal approach”.

7.   UNCERTAINTY ASSESSMENTS

Uncertainty assessments required to demonstrate compliance with relevant tiers in Section 2 shall be determined by means of an error propagation calculation taking into account the uncertainty of all relevant elements of the emission calculation. For the continuous measurement the following sources of uncertainty should be assessed in accordance with EN 14181 and ISO 14956:2002:

—	the specified uncertainty of continuous measurement equipment, including sampling,

—	uncertainties associated to the calibration, and

—	additional uncertainty connected to how the monitoring equipment is used in practice.

For the calculation of the total uncertainty to be used in Section 2.2, hourly N2O concentrations as determined pursuant to Section 2.3 shall be used. For the purpose of uncertainty calculation only, hourly N2O concentrations below 20 mg/Nm3 shall be substituted by a default value of 20 mg/Nm3.

The operator, via the quality assurance and control process, shall manage and reduce the remaining uncertainties of the emissions data in his emissions report. During the verification process, the verifier shall check the correct application of the approved monitoring methodology, and shall assess the management and reduction of remaining uncertainties via the operator’s quality assurance and control procedures.

8.   CONTROL AND VERIFICATION

8.1.   CONTROL

In addition to the requirements in Annex I, Sections 10.1, 10.2 and 10.3, the following quality assurance procedures shall apply:

—	quality assurance of the continuous measurements of the concentration of N2O and oxygen shall take place in accordance with EN 14181,

—	the installed measurement equipment shall be calibrated by means of parallel measurements once every three years,

—	where emission limit values (ELVs) are typically used as the basis for calibration of continuous emissions monitors, and where no ELV exists for N2O or O2, then the annual average hourly concentration shall be used as a proxy for such ELVs,

—	the QAL 2 should be done with suitable reference gases in addition to the sample gas, to ensure that a wide enough calibration range is assessed,

—	the measurement equipment that measures the flue gas flow volume shall be calibrated annually or when the plant is maintained, whichever is sooner. Quality assurance of flue gas flow volume does not need to be performed in accordance with EN 14181,

—	if internal audits find non-compliance with EN 14181 or that recalibration has to be performed, this shall be reported to the competent authority without undue delay.

8.2.   VERIFICATION

In addition to the verification requirements set out in Section 10.4, the following will be checked:

—	correctness of application of requirements of the standards named under Sections 7 and 8.1 of this Annex,

—	calculation approaches and results where missing data has been substituted by calculated values,

—	plausibility of calculated substitute values and measured values,

—	any comparative assessments corroborating emissions results and calculation based methods and the reporting of activity data, emission factors and alike.

9.   REPORTING

Total annual emissions of N2O shall be reported in tonnes to three decimal places and as CO2(e) to rounded tonnes.

In addition to the reporting requirements set out in Section 8 of Annex I, operators of installations covered by this Annex shall report the following information for installations:

(a)	annual process unit operating time and total plant operating time;

(b)	production data for each unit and the method used to determine the quantity of product;

(c)	measurement criteria used in the quantification of each parameter;

(d)	the uncertainty for each measured and calculated parameter (including gas concentrations, flue gas flow, calculated emissions) and the resulting total uncertainty of the hourly load and/or annual emission figure;

(e)	details of any equipment malfunctions that affected emissions and emissions/flue gas flow measurements and calculations, including number of occasions, hours affected, duration and dates of malfunctions;

(f)	details of when Section 6.2 of this Annex needed to be applied, including number of occasions, hours affected, calculations and substitute values used;

(g)	the input data used in any corroborating assessments in accordance with Annex I, Sections 6.3(c) and 4.3 to check the annual N2O emissions.’