CDM Met Panel Twenty-fourt meeting Page 1 Metodological Tool Tool to determine project emissions from flaring es containing metane I. DEFINITIONS, SCOPE, APPLICABILITY AND PARAMETERS Definitions For te purpose of tis tool, te following definitions apply: Residual stream. Gas stream containing metane tat is to be flared in our as part of te project activity. Flare efficiency. Metane destruction efficiency of te flare in our, defined as te ratio between te mass flow rate of metane in te exaust of te flare and te mass flow rate of metane in stream tat is flared (bot referred to in dry basis 1 and normal (NTP) conditions). Enclosed flare. Enclosed flares are defined as devices were te is burned in a cylindrical or rectilinear enclosure tat includes a burning system and a damper were air for te combustion reaction is admitted. Open flare. Open flares are defined as devices were te is burned in an open air tip wit or witout any auxiliary fluid assistance. Scope and applicability Tis tool provides procedures to calculate project emissions from flaring of a stream (RG) containing metane. Tis tool is applicable under te following conditions: Te stream to be flared contains no oter combustible es tan metane, carbon monoxide and ydrogen; Te stream to be flared sall be obtained from decomposition of organic material (troug landfills, bio-digesters or anaerobic lagoons, among oters) or from es vented in coal mines (coal mine metane and coal bed metane). 1 Dry basis refers to dry conditions (moisture must be discounted from flow rate and composition).
CDM Met Panel Twenty-fourt meeting Page Parameters Tis tool provides procedures to determine te following parameters : Parameter SI Unit Description PE flare,y tco e Project emissions from flaring of te stream in year y η flare, - Flare efficiency in our based on measurements or default values. Te following data are required by tis tool: Parameter SI Unit Description fv i, - Volumetric fraction of component i in te in te our were i = CH 4, CO, CO, O, H, N FV RG, m 3 / Volumetric flow rate of te in dry basis at normal (NTP) conditions in te our t O, - Volumetric fraction of O in te exaust of te flare in te our (only in case te flare efficiency is continuously monitored) fv CH4,FG, mg/m 3 Concentration of metane in te exaust of te flare in dry basis at normal conditions in te our (only in te case te flare efficiency is continuously monitored) T flare C Temperature in te exaust of te enclosed flare Any oter parameters required to monitor proper operation of te flare according to te manufacturer s specification (only in te case of use of a default value for te flare efficiency of enclosed and open flares) II. BASELINE METHODOLOGY PROCEDURE Project emissions from flaring of te stream are calculated based on te flare efficiency and te mass flow rate of metane in te stream tat is flared. Te flare efficiency depends on bot te actual efficiency of combustion in te flare and te time tat te flare is operating. Te efficiency of combustion in te flare is calculated from te metane content in te exaust of te flare, corrected for te air used in te combustion process, and te metane content in te. In case of open flares, te flare efficiency cannot be measured in a reliable manner (i.e. external air will be mixed and will dilute te remaining metane) and a default value of 50% 3 is to be used provided tat it can be demonstrated tat te flare is operational (e.g. troug a flame detection system reporting electronically on continuous basis)). If te flare is not operational te default value to be adopted for flare efficiency is 0%. Normal (NTP) conditions are 101.35 kpa and 73.15 K. 3 Wenever te default value for te flare efficiency (eiter open flare or enclosed flare) is to be used for calculation of project emissions in equation 15 below, te value sould be converted into fraction (e.g. 50/100= 0.5) before use in te equation.
CDM Met Panel Twenty-fourt meeting Page 3 For enclosed flares, te temperature in te exaust of te flare is measured to determine weter te flare is operating or not. For enclosed flares, eiter of te following two options can be used to determine te flare efficiency: (a) To use a 90% default value. Continuous monitoring of compliance wit manufacturer s specification of flare (temperature, flow rate of at te inlet of te flare) must be performed. If in a specific our any of te parameters are out of te limit of manufacturer s specifications, a 50% default value for te flare efficiency sould be used for te calculations for tis specific our. (b) Continuous monitoring of te metane destruction efficiency of te flare (flare efficiency). In bot cases, if tere is no record of te temperature of te exaust of te flare or if te recorded temperature is less tan 500 C for any particular our, it sall be assumed tat during tat our te flare efficiency is zero. Project participants sould document in te CDM-PDD, wic type of flare and wic approac to determine te flare efficiency is used. In case of use of te default value for te metane destruction efficiency, te manufacturer s specifications for te operation of te flare and te required data and procedures to monitor tese specifications sould be documented in te CDM- PDD. Tis tool involves te following seven steps: STEP 1: Determination of te mass flow rate of te tat is flared STEP : Determination of te mass fraction of carbon, ydrogen, oxygen and nitrogen in te STEP 3: Determination of te volumetric flow rate of te exaust on a dry basis STEP 4: Determination of metane mass flow rate of te exaust on a dry basis STEP 5: Determination of metane mass flow rate of te on a dry basis STEP 6: Determination of te ourly flare efficiency STEP 7: Calculation of annual project emissions from flaring based on measured ourly values or based on default flare efficiencies. Project participants sall apply tese steps to calculate project emissions from flaring (PE flare,y ) based on te measured ourly flare efficiency or based on te default values for te flare efficiency (η flare, ). Note tat steps 3 and 4 are only applicable in case of enclosed flares and continuous monitoring of te flare efficiency. Te calculation procedure in tis tool determines te flow rate of metane before and after te destruction in te flare, taking into account te amount of air supplied to te combustion reaction and te exaust composition (oxygen and metane). Te flare efficiency is calculated for eac our of a year based eiter on measurements or default values plus operational parameters. Project emissions are determined by multiplying te metane flow rate in te wit te flare efficiency for eac our of te year.
CDM Met Panel Twenty-fourt meeting Page 4 STEP 1. Determination of te mass flow rate of te tat is flared Tis step calculates te mass flow rate in eac our, based on te volumetric flow rate and te density of te. Te density of te is determined based on te volumetric fraction of all components in te. FM RG, RG, n, FVRG, = ρ (1) Were: FM RG, kg/ Mass flow rate of te in our ρ RG,n, kg/m 3 Density of te at normal conditions in our FV RG, m 3 / Volumetric flow rate of te in dry basis at normal conditions in te our and: ρ RG, n, = Pn Ru MM RG, T n () Were: ρ RG,n, kg/m 3 Density of te at normal conditions in our P n Pa Atmosperic pressure at normal conditions (101 35) R u Pa.m 3 /kmol.k Universal ideal constant (8 314) MM RG, kg/kmol Molecular mass of te in our T n K Temperature at normal conditions (73.15) and: MM RG, ( i, i i = fv * MM ) (3) Were: MM RG, kg/kmol Molecular mass of te in our fv i, - Volumetric fraction of component i in te in te our MM i kg/kmol Molecular mass of component i I Te components CH 4, CO, CO, O,H, N As a simplified approac, project participants may only measure te volumetric fraction of metane and consider te difference to 100% as being nitrogen (N ).
CDM Met Panel Twenty-fourt meeting Page 5 STEP. Determination of te mass fraction of carbon, ydrogen, oxygen and nitrogen in te Determine te mass fractions of carbon, ydrogen, oxygen and nitrogen in te, calculated from te volumetric fraction of eac component i in te, as follows: fm j, = i fv i, AM MM j RG, NA j,i (4) Were: fm j, - Mass fraction of element j in te in our fv i, - Volumetric fraction of component i in te in te our AM j kg/kmol Atomic mass of element j NA j,i - Number of atoms of element j in component i MM RG, kg/kmol Molecular mass of te in our j Te elements carbon, ydrogen, oxygen and nitrogen i Te components CH 4, CO, CO, O,H, N STEP 3. Determination of te volumetric flow rate of te exaust on a dry basis Tis step is only applicable if te metane combustion efficiency of te flare is continuously monitored. Determine te average volumetric flow rate of te exaust in eac our based on a stoiciometric calculation of te combustion process, wic depends on te cemical composition of te, te amount of air supplied to combust it and te composition of te exaust, as follows: TV n, FG, Vn, FG, FM RG, = (5) Were: TV n,fg, m 3 / Volumetric flow rate of te exaust in dry basis at normal conditions in our m 3 /kg residual Volume of te exaust of te flare in dry basis at normal V n,fg, FM RG, kg residual / conditions per kg of in our Mass flow rate of te in te our
CDM Met Panel Twenty-fourt meeting Page 6 V n FG, Vn, CO, + Vn, O, + Vn, N, = (6), Were: V n,fg, m 3 /kg residual Volume of te exaust of te flare in dry basis at normal conditions per kg of in te our V n,co, m 3 /kg residual Quantity of CO volume free in te exaust of te flare at normal conditions per kg of in te our V n,n, m 3 /kg residual Quantity of N volume free in te exaust of te flare at normal conditions per kg of in te our V n,o, m 3 /kg residual Quantity of O volume free in te exaust of te flare at normal conditions per kg of in te our V MV n O, = no,, n (7) Were: V n,o, m 3 /kg residual Quantity of O volume free in te exaust of te flare at normal conditions per kg of in te our n O, kmol/kg Quantity of moles O in te exaust of te flare per kg flared in our MV n m 3 /kmol Volume of one mole of any ideal at normal temperature and pressure (.4 L/mol) fmn, 00AM 1 MF + MFO * [ F + n ] O V n, N = MV, n O, N (8) Were: V n,n, m 3 /kg Quantity of N volume free in te exaust of te flare at normal conditions per kg of in te our MV n m 3 /kmol Volume of one mole of any ideal at normal temperature and pressure (.4 m 3 /Kmol) fm N, - Mass fraction of nitrogen in te in te our AM n kg/kmol Atomic mass of nitrogen MF O - O volumetric fraction of air kmol/kg Stociometric quantity of moles of O required for a complete F n O, kmol/kg oxidation of one kg in our Quantity of moles O in te exaust of te flare per kg flared in our
CDM Met Panel Twenty-fourt meeting Page 7 V n, CO, = fm AM C, C MV n (9) Were: V n,co, m 3 /kg residual Quantity of CO volume free in te exaust of te flare at normal conditions per kg of in te our fm C, - Mass fraction of carbon in te in te our AM C kg/kmol Atomic mass of carbon MV n m 3 /kmol Volume of one mole of any ideal at normal temperature and pressure (.4 m 3 /Kmol) n t O, fm C fm 1 MF, N, O + +, F (10) O = ( 1 ( t ) O MFO AM C AM N MF, / ) O Were: n O, kmol/kg Quantity of moles O in te exaust of te flare per kg flared in our t O, - Volumetric fraction of O in te exaust in te our MF O - Volumetric fraction of O in te air (0.1) F kmol/kg Stociometric quantity of moles of O required for a complete oxidation of one kg in our fm j, - Mass fraction of element j in te in our (from equation 4) AM j kg/kmol Atomic mass of element j j Te elements carbon (index C) and nitrogen (index N) F fm fm fm C, H, O, = + (11) AM C 4AM H AM O Were: F kmol O /kg Stoiciometric quantity of moles of O required for a complete oxidation of one kg in our fm j, - Mass fraction of element j in te in our (from equation 4) AM j kg/kmol Atomic mass of element j j Te elements carbon (index C), ydrogen (index H) and oxygen (index O)
CDM Met Panel Twenty-fourt meeting Page 8 STEP 4. Determination of metane mass flow rate in te exaust on a dry basis Tis step is only applicable if te metane combustion efficiency of te flare is continuously monitored. Te mass flow of metane in te exaust is based on te volumetric flow of te exaust and te measured concentration of metane in te exaust, as follows: TM FG, = TV n,fg, *fv 1000000 CH4,FG, (1) Were: TM FG, kg/ Mass flow rate of metane in te exaust of te flare in dry basis at normal conditions in te our TV n,fg, m 3 / exaust Volumetric flow rate of te exaust in dry basis at normal conditions in our fv CH4,FG, mg/m 3 Concentration of metane in te exaust of te flare in dry basis at normal conditions in our STEP 5. Determination of metane mass flow rate in te on a dry basis Te quantity of metane in te flowing into te flare is te product of te volumetric flow rate of te (FV RG, ), te volumetric fraction of metane in te (fv CH4,RG, ) and te density of metane (ρ CH4,n, ) in te same reference conditions (normal conditions and dry or wet basis). It is necessary to refer bot measurements (flow rate of te and volumetric fraction of metane in te ) to te same reference condition tat may be dry or wet basis. If te moisture is significant (temperature greater tan 60ºC), te measured flow rate of te tat is usually referred to wet basis sould be corrected to dry basis due to te fact tat te measurement of metane is usually undertaken on a dry basis (i.e. water is removed before sample analysis). TM RG, = FVRG, fvch 4, RG, ρch 4, n (13) Were: TM RG, kg/ Mass flow rate of metane in te in te our FV RG, m 3 / Volumetric flow rate of te in dry basis at normal conditions in our fv CH4,RG, - Volumetric fraction of metane in te on dry basis in our (NB: tis corresponds to fv i,rg, were i refers to metane). ρ CH4,n kg/m 3 Density of metane at normal conditions (0.716)
CDM Met Panel Twenty-fourt meeting Page 9 STEP 6. Determination of te ourly flare efficiency Te determination of te ourly flare efficiency depends on te operation of flare (e.g. temperature), te type of flare used (open or enclosed) and, in case of enclosed flares, te approac selected by project participants to determine te flare efficiency (default value or continuous monitoring). In case of enclosed flares and continuous monitoring of te flare efficiency, te flare efficiency in te our (η flare, ) is 0% if te temperature of te exaust of te flare (T flare ) is below 500 C during more tan 0 minutes during te our. determined as follows in cases were te temperature of te exaust of te flare (T flare ) is above 500 C for more tan 40 minutes during te our : TM, = 1 FG, η flare (14) TM RG, Were: η flare, - Flare efficiency in te our TM FG, kg/ Metane mass flow rate in exaust averaged in a period of time t (our, two monts or year) TM RG, kg/ Mass flow rate of metane in te in te our In case of enclosed flares and use of te default value for te flare efficiency, te flare efficiency in te our (η flare, ) is: 0% if te temperature in te exaust of te flare (T flare ) is below 500 C for more tan 0 minutes during te our. 50%, if te temperature in te exaust of te flare (T flare ) is above 500 C for more tan 40 minutes during te our, but te manufacturer s specifications on proper operation of te flare are not met at any point in time during te our. 90%, if te temperature in te exaust of te flare (T flare ) is above 500 C for more tan 40 minutes during te our and te manufacturer s specifications on proper operation of te flare are met continuously during te our. In case of open flares, te flare efficiency in te our (η flare, ) is 0% if te flame is not detected for more tan 0 minutes during te our. 50%, if te flare is detected for more tan 0 minutes during te our.
CDM Met Panel Twenty-fourt meeting Page 10 STEP 7. Calculation of annual project emissions from flaring Project emissions from flaring are calculated as te sum of emissions from eac our, based on te metane flow rate in te (TM RG, ) and te flare efficiency during eac our (η flare, ), as follows: ( ) 8760 GWPCH 4 PE flare, y = TM RG, 1 η flare, (15) 1000 = 1 Were: PE flare,y tco e Project emissions from flaring of te stream in year y TM RG, kg/ Mass flow rate of metane in te in te our η flare, - Flare efficiency in our GWP CH4 tco e/tch 4 Global Warming Potential of metane valid for te commitment period Data and parameters not monitored Te only parameters and data tat is not monitored are te constants used in equations, as listed in Table 1 below. Table 1. Constants used in equations Parameter SI Unit Description Value MM CH4 kg/kmol Molecular mass of metane 16.04 MM CO kg/kmol Molecular mass of carbon monoxide 8.01 MM CO kg/kmol Molecular mass of carbon dioxide 44.01 MM O kg/kmol Molecular mass of oxygen 3.00 MM H kg/kmol Molecular mass of ydrogen.0 MM N kg/kmol Molecular mass of nitrogen 8.0 AM c kg/kmol Atomic mass of carbon 1.00 (g/mol) AM kg/kmol Atomic mass of ydrogen 1.01 (g/mol) AM o kg/kmol Atomic mass of oxygen 16.00 (g/mol) AM n kg/kmol Atomic mass of nitrogen 14.01 (g/mol) P n Pa Atmosperic pressure at normal conditions 101 35 R u Pa.m 3 /kmol.k Universal ideal constant 8 314.47 T n K Temperature at normal conditions 73.15 MF O Dimensionless O volumetric fraction of air 0.1 GWP CH4 tco /tch 4 Global warming potential of metane 1 MV n m 3 /Kmol Volume of one mole of any ideal at normal temperature and pressure.414
CDM Met Panel Twenty-fourt meeting Page 11 Parameter SI Unit Description Value ρ CH4, n kg/m 3 Density of metane at normal conditions 0.716 NA i,j Dimensionless Number of atoms of element j in component i, depending on molecular structure III. MONITORING METHODOLOGY PROCEDURE Data and parameters to be monitored All monitored data must be linked in time, i.e. calculations sall be performed considering only a set of data acquired in te same time interval in case of continuous monitoring. As noted above, project participants may use one our or a smaller discrete time interval. fv i, Data / Parameter: Data unit: - Description: Volumetric fraction of component i in te in te our were i = CH 4, CO, CO, O,H, N Source of data: Measurements by project participants using a continuous analyser Measurement Ensure tat te same basis (dry or wet) is considered for tis measurement procedures: and te measurement of te volumetric flow rate of te (FV RG, ) wen te temperature exceeds 60 ºC Monitoring Continuously. Values to be averaged ourly or at a sorter time interval frequency: QA/QC procedures Analysers must be periodically calibrated according to te manufacturer s recommendation. A zero ceck and a typical value ceck sould be performed by comparison wit a standard certified. Any comment: As a simplified approac, project participants may only measure te metane content of te and consider te remaining part as N. FV RG, Data / Parameter: Data unit: m 3 / Description: Volumetric flow rate of te in dry basis at normal conditions in te our Source of data: Measurements by project participants using a flow meter Measurement Ensure tat te same basis (dry or wet) is considered for tis measurement procedures: and te measurement of volumetric fraction of all components in te (fv i, ) wen te temperature exceeds 60 ºC Monitoring Continuously. Values to be averaged ourly or at a sorter time interval frequency: QA/QC procedures Flow meters are to be periodically calibrated according to te manufacturer s recommendation. Any comment:
CDM Met Panel Twenty-fourt meeting Page 1 t O, Data / Parameter: Data unit: - Description: Volumetric fraction of O in te exaust of te flare in te our Source of data: Measurements by project participants using a continuous analyser Measurement Extractive sampling analysers wit water and particulates removal devices procedures: or in situ analysers for wet basis determination. Te point of measurement (sampling point) sall be in te upper section of te flare (80% of total flare eigt). Sampling sall be conducted wit appropriate sampling probes adequate to ig temperatures level (e.g. inconel probes). An excessively ig temperature at te sampling point (above 700 ºC) may be an indication tat te flare is not being adequately operated or tat its capacity is not adequate to te actual flow. Monitoring Continuously. Values to be averaged ourly or at a sorter time interval frequency: QA/QC procedures Analysers must be periodically calibrated according to te manufacturer s recommendation. A zero ceck and a typical value ceck sould be performed by comparison wit a standard. Any comment: Monitoring of tis parameter is only applicable in case of enclosed flares and continuous monitoring of te flare efficiency. fv CH4,FG, Data / Parameter: Data unit: mg/m 3 Description: Concentration of metane in te exaust of te flare in dry basis at normal conditions in te our Source of data: Measurements by project participants using a continuous analyser Measurement Extractive sampling analysers wit water and particulates removal devices procedures: or in situ analyser for wet basis determination. Te point of measurement (sampling point) sall be in te upper section of te flare (80% of total flare eigt). Sampling sall be conducted wit appropriate sampling probes adequate to ig temperatures level (e.g. inconel probes). An excessively ig temperature at te sampling point (above 700 ºC) may be an indication tat te flare is not being adequately operated or tat its capacity is not adequate to te actual flow. Monitoring Continuously. Values to be averaged ourly or at a sorter time interval frequency: QA/QC procedures Analysers must be periodically calibrated according to manufacturer s recommendation. A zero ceck and a typical value ceck sould be performed by comparison wit a standard. Any comment: Monitoring of tis parameter is only applicable in case of enclosed flares and continuous monitoring of te flare efficiency. Measurement instruments may read ppmv or % values. To convert from ppmv to mg/m 3 simply multiply by 0.716. 1% equals 10 000 ppmv.
CDM Met Panel Twenty-fourt meeting Page 13 T flare Data / Parameter: Data unit: C Description: Temperature in te exaust of te flare Source of data: Measurements by project participants Measurement Measure te temperature of te exaust stream in te flare by a Type N procedures: termocouple. A temperature above 500 ºC indicates tat a significant amount of es are still being burnt and tat te flare is operating. Monitoring Continuously. frequency: QA/QC procedures Termocouples sould be replaced or calibrated every year. Any comment: An excessively ig temperature at te sampling point (above 700 ºC) may be an indication tat te flare is not being adequately operated or tat its capacity is not adequate to te actual flow. Data / Parameter: Oter flare operation parameters Data unit: - Description: Tis sould include all data and parameters tat are required to monitor weter te flare operates witin te range of operating conditions according to te manufacturer s specifications including a flame detector in case of open flares. Source of data: Measurements by project participants Measurement procedures: Monitoring Continuously frequency: QA/QC procedures Any comment: Only applicable in case of use of a default value IV. REFERENCES Fundamentals of Classical Termodynamics; Gordon J. Van Wylen, Ricard E. Sonntag and Claus Borgnakke; 4º Edition, 1994, Jon Wiley & Sons, Inc.