DRAFT. Landfill Gas, Methane, and NMOC Generation Rates LFG: Volumetric Flow Rate (Peak)

Transcription

1 Sheet: 1 of 9 Landfill Gas, Methane, and NMOC Generation Rates LFG: Volumetric Flow Rate (Peak) m 3 /yr ( 10 6 ) m 3 /min scf/yr ( 10 6 ) scfm 1,599 1,789 Methane: Volumetric Flow Rate (Peak) m 3 /yr ( 10 6 ) m 3 /min scf/yr ( 10 6 ) scfm NMOC: Mass Flow Rate (Peak) Mg/yr kg/hr g/s ton/yr l/hr Values for m 3 /yr and Mg/yr (with rounding) are taken from LandGEM modeling output presented in Attachment C of permit application; other values are converted. 2 Based on methane content of 50 percent in landfill gas. 3 Based on reported average concentration of 389 ppmv as hexane.

2 Sheet: 2 of 9 Fugitive Emissions Source: LANDFILL SCENARIO A: 75 Percent Collection Efficiency SCENARIO B: 95 Percent Collection Efficiency LFG Fugitive Emissions Annual Average Annual Average MMscf scfm MMscf scfm 940 1, , LFG Fugitive Emissions l/mmscf l/hr ton/yr l/mmscf l/hr ton/yr VOC 87 a VOC 87 a H 2 S H 2 S a Based on reported average NMOC concentration (389 ppmv as hexane) as proxy for VOC. EF = 389 ppmv l/lmol scf/lmol = 87 l/mmscf. Based on average hydrogen sulfide concentration (630 ppmv) in landfill gas samples collected, August EF = 630 ppmv l/lmol scf/lmol = 56 l/mmscf. Sample calculation for VOC: 235 MMscf/yr 87 l/mmscf 8760 hr/yr = 2.33 l/hr = 10.2 ton/yr Note: Stated emissions represent fugitive emissions, excluding any undestroyed fractions passing through control devices.

3 Sheet: 3 of 9 Secondary Emissions Source: CONTROL DEVICES SCENARIO A1: 75 Percent Collection Efficiency Maximum Use of Engines LFG Higher Heating Value, Btu/scf Max. LFG Delivered to Control Devices: Engines Flare Annual Average Device Capacities Heat Input Flow Rate MMscf scfm MMBtu/hr scfm 940 1,789 Engine EU ,130 Engine EU Engines EU01 + EU , ,342 Flare EU ,000 l/mmscf Engine EU01 Engine EU02 Flare EU03 l/hr ton/yr l/mmscf l/hr ton/yr l/mmscf l/hr ton/yr l/hr ton/yr CO 235 a a f NOx 125 a a f PM a a a SO 2 w/o pretreatment VOC 1.7 d d d HCl 3.7 e e e a USEPA, AP-42 Tale 2.4-5, "Emission Rates for Secondary Compounds Exiting Control Devices," adjusted for landfill 50% methane content. c Sulfur removal system is no longer utlized. d e Based on highest measured total reduced sulfur concentration in landfill gas to date (~800 ppmv); 100% conversion to sulfur dioxide assumed. EF = 800 ppmv l/lmol scf/lmol = 133 l/mmscf. Based on reported average NMOC concentration (389 ppmv as hexane) as proxy for VOC; assumed VOC destruction efficiency = 98%. EF = (1 0.98) 389 ppmv l/lmol scf/lmol = 1.7 l/mmscf. Based on total chlorine concentration of 39 ppmv in landfill gas, calculated stoichiometrically from analytical data on individual chlorinated compounds; 100% conversion to hydrogen chloride assumed. EF = 39 ppmv l/lmol scf/lmol = 3.7 l/mmscf. f AP-42 Tale , Emission Factors for Flare Operations, Septemer Emission factors ased on fuel HHV of 500 Btu/scf. For CO, EF = 0.37 l/mmbtu 500 Btu/scf = 185 l/mmscf. For NOX, EF = l/mmbtu 500 Btu/scf = 34 l/mmscf.

4 Sheet: 4 of 9 Secondary Emissions Source: CONTROL DEVICES SCENARIO A2: 75 Percent Collection Efficiency Maximum Use of Flare LFG Higher Heating Value, Btu/scf Max. LFG Delivered to Control Devices: Engines Flare Annual Average Device Capacities Heat Input Flow Rate MMscf scfm MMBtu/hr scfm 940 1,789 Engine EU Engine EU ,342 Engines EU01 + EU , ,342 Flare EU ,000 Engine EU01 Engine EU02 Flare EU03 l/mmscf l/hr ton/yr l/mmscf l/hr ton/yr l/mmscf l/hr ton/yr l/hr ton/yr CO 235 a a f NOx 125 a a f PM10 24 a a a SO2 w/o pretreatment VOC 1.7 d d d HCl 3.7 e e e a USEPA, AP-42 Tale 2.4-5, "Emission Rates for Secondary Compounds Exiting Control Devices," adjusted for landfill 50% methane content. c Sulfur removal system is no longer utlized. d e Based on highest measured total reduced sulfur concentration in landfill gas to date (~800 ppmv); 100% conversion to sulfur dioxide assumed. EF = 800 ppmv l/lmol scf/lmol = 133 l/mmscf. Based on reported average NMOC concentration (389 ppmv as hexane) as proxy for VOC; assumed VOC destruction efficiency = 98%. EF = (1 0.98) 389 ppmv l/lmol scf/lmol = 1.7 l/mmscf. Based on total chlorine concentration of 39 ppmv in landfill gas, calculated stoichiometrically from analytical data on individual chlorinated compounds; 100% conversion to hydrogen chloride assumed. EF = 39 ppmv l/lmol scf/lmol = 3.7 l/mmscf. f AP-42 Tale , Emission Factors for Flare Operations, Septemer Emission factors ased on fuel HHV of 500 Btu/scf. For CO, EF = 0.37 l/mmbtu 500 Btu/scf = 185 l/mmscf. For NOX, EF = l/mmbtu 500 Btu/scf = 34 l/mmscf.

5 Sheet: 5 of 9 Secondary Emissions Source: CONTROL DEVICES SCENARIO B1: 95 Percent Collection Efficiency Maximum Use of Engines LFG Higher Heating Value, Btu/scf Max. LFG Delivered to Control Devices: Engines Flare Annual Average Device Capacities Heat Input Flow Rate MMscf scfm MMBtu/hr scfm 940 1,789 Engine EU ,130 Engine EU Engines EU01 + EU , ,700 Flare EU ,000 l/mmscf Engine EU01 Engine EU02 Flare EU03 l/hr ton/yr l/mmscf l/hr ton/yr l/mmscf l/hr ton/yr l/hr ton/yr CO 235 a a f NOx 125 a a f PM10 24 a a a SO2 w/o pretreatment VOC 1.7 d d d HCl 3.7 e e e a USEPA, AP-42 Tale 2.4-5, "Emission Rates for Secondary Compounds Exiting Control Devices," adjusted for landfill 50% methane content. c Sulfur removal system is no longer utlized. d e f Based on highest measured total reduced sulfur concentration in landfill gas to date (~800 ppmv); 100% conversion to sulfur dioxide assumed. EF = 800 ppmv l/lmol scf/lmol = 133 l/mmscf. Based on reported average NMOC concentration (389 ppmv as hexane) as proxy for VOC; assumed VOC destruction efficiency = 98%. EF = (1 0.98) 389 ppmv l/lmol scf/lmol = 1.7 l/mmscf. Based on total chlorine concentration of 39 ppmv in landfill gas, calculated stoichiometrically from analytical data on individual chlorinated compounds; 100% conversion to hydrogen chloride assumed. EF = 39 ppmv l/lmol scf/lmol = 3.7 l/mmscf. AP-42 Tale , Emission Factors for Flare Operations, Septemer Emission factors ased on fuel HHV of 500 Btu/scf. For CO, EF = 0.37 l/mmbtu 500 Btu/scf = 185 l/mmscf. For NOX, EF = l/mmbtu 500 Btu/scf = 34 l/mmscf

6 Sheet: 6 of 9 Secondary Emissions Source: CONTROL DEVICES SCENARIO B2: 95 Percent Collection Efficiency Maximum Use of Flare LFG Higher Heating Value, Btu/scf Max. LFG Delivered to Control Devices: Engines Flare Annual Average Device Capacities Heat Input Flow Rate MMscf scfm MMBtu/hr scfm 940 1,789 Engine EU Engine EU ,700 Engines EU01 + EU , ,700 Flare EU ,000 Engine EU01 Engine EU02 Flare EU03 l/mmscf l/hr ton/yr l/mmscf l/hr ton/yr l/mmscf l/hr ton/yr l/hr ton/yr CO 235 a a f NOx 125 a a f PM10 24 a a a SO2 w/o pretreatment VOC 1.7 d d d HCl 3.7 e e e a USEPA, AP-42 Tale 2.4-5, "Emission Rates for Secondary Compounds Exiting Control Devices," adjusted for landfill 50% methane content. c Sulfur removal system is no longer utlized. d e f Based on highest measured total reduced sulfur concentration in landfill gas to date (~800 ppmv); 100% conversion to sulfur dioxide assumed. EF = 800 ppmv l/lmol scf/lmol = 133 l/mmscf. Based on reported average NMOC concentration (389 ppmv as hexane) as proxy for VOC; assumed VOC destruction efficiency = 98%. EF = (1 0.98) 389 ppmv l/lmol scf/lmol = 1.7 l/mmscf. Based on total chlorine concentration of 39 ppmv in landfill gas, calculated stoichiometrically from analytical data on individual chlorinated compounds; 100% conversion to hydrogen chloride assumed. EF = 39 ppmv l/lmol scf/lmol = 3.7 l/mmscf. AP-42 Tale , Emission Factors for Flare Operations, Septemer Emission factors ased on fuel HHV of 500 Btu/scf. For CO, EF = 0.37 l/mmbtu 500 Btu/scf = 185 l/mmscf. For NOX, EF = l/mmbtu 500 Btu/scf = 34 l/mmscf.

7 Sheet: 7 of 9 Engineer: chm Date: 12/05/07 Emission Calculations: Hazardous Air s (HAPs) a Measured Concentrations in Landfill Gas: CAS Numer HAP Molecular Weight Concentration ppmv a Benzene Caron disulfide Caronyl sulfide Chloroethane (Ethyl chloride) Cumene (Isopropylenzene) Ethyl enzene Hexane (n-hexane) Hydrochloric acid Methylene Chloride (Dichloromethane) Methyl ethyl ketone (MEK) Methyl isoutyl ketone (MIBK, 4-Methyl-2-pentanone) Methyl-tert utyl ether (MBTE) Styrene, monomer Perchloroethylene (PCE, Tetrachloroethylene) Toluene Methyl chloroform (1,1,1-Trichloroethane) Trichloroethylene Chloroethylene (Vinyl chloride) Xylene (all isomers) Average: : Values as reported y GZA GeoEnvironmental, Inc., in "Air Quality Modeling Report for Regulated Toxic Air s," Four Hills Landfill, Nashua, New Hampshire, Septemer Calculated stoichiometrically from measured concentrations of individual chlorinated compounds in landfill gas samples, August Calculation of potential emissions: Potential emissions of total HAPs, ased on unweighted MW of and maximum fugitive emissions of 235 MMscf/yr (from Sheet 2): 102 ppmv l/lmol scf/lmol 235 MMscf/yr 2000 l/ton = 2.9 ton/yr. Potential emissions of hydrochloric acid, ased on maximum controlled emissions of 893 MMscf/yr (from Sheets 5 and 6): 3.6 l/mmscf 893 MMscf/yr 2000 l/ton = 1.6 ton/yr.

8 Sheet: 8 of 9 Engineer: chm Date: 12/05/07 Maximum Predicted Impacts: Sulfur Dioxide SO 2 Average Period Maximum Impact PSD Increment Background Conc. Impact NAAQS Percent of NAAQS Pass/Fail µg/m 3 µg/m 3 µg/m 3 µg/m 3 µg/m 3 3-hr Pass 24-hr Pass Annual Pass Notes: 1. Annual results reflect maximum impacts; results for other averaging periods are high 2 nd high impacts. 2. Impacts are conservatively ased on SO 2 emission rates without sulfur removal pretreatment. 3. SO 2 ackground data are from Concord, NH,

9 Sheet: 9 of 9 Engineer: chm Date: 12/05/07 Maximum Predicted Impacts: RTAPs Molecular Weight Conc. in LFG 24-hr Impact 24-hr AAL Annual Impact Annual AAL CAS Numer Compound of AAL ppmv µg/m 3 µg/m 3 µg/m 3 µg/m ,2,4-Trimethylenzene (as Trimethylenzene) Pass ,3,5-Trimethylenzene (as Trimethylenzene) Pass p-dichloroenzene (1,4-Dichloroenzene) Pass Isopropyl alcohol (2-Propanol) Pass Acetone (2-Propanone) Pass Benzene Pass Butane Pass n-butanol Pass Butanol (sec-butanol) Pass n-butyl acetate Pass Caron disulfide Pass Carene Pass Chloroenzene Pass Chloroethane (Ethyl chloride) Pass cis-1,2-dichloroethylene (cis) Pass Cumene (Isopropylenzene) Pass Cyclohexane Pass Chlorodifluoromethane (Freon 22) Pass Dichlorodifluoromethane (Freon 12) Pass Dimethyl sulfide Pass Ethanol Pass Ethyl acetate Pass Ethyl enzene Pass Ethyl mercaptan (Ethanithiol) Pass CFC-114 (1,2-Dichlorotetrafluoroethane) Pass Heptane Pass Hexane (n-hexane) Pass Hydrogen chloride n/a Pass Hydrogen sulfide Pass Isopentane (Pentane, 2-methylutane) Pass Methyl mercaptan (Methanethiol) Pass Methylene Chloride (Dichloromethane) Pass Methyl ethyl ketone (MEK) Pass Methyl isoutyl ketone (MIBK, 4-Methyl-2-pentanone) Pass Methyl-tert utyl ether (MBTE) Pass Nonane, all isomers Pass Pentane (all isomers) Pass Pinene (alpha) Pass Pinene (eta) Pass Styrene, monomer Pass Tetrahydrofuran Pass Perchloroethylene (PCE, Tetrachloroethylene) Pass Toluene Pass Methyl chloroform (1,1,1-Trichloroethane) Pass Trichloroethylene Pass CFC-11 (Trichlorofluoromethane, Freon 11, Flourotrichloromethane) Pass Chloroethylene (Vinyl chloride) Pass Xylene (all isomers) Pass Percent Notes: 1. Hydrogen chloride was modeled explicitly. Results for other RTAPs were scaled from the methane impacts using the ratios of molecular weights and concentrations in landfill gas in accordance with the following formula: RTAP impact = methane impact (conc. RTAP in gas conc. methane in gas) (mol. wt. RTAP mol. wt. methane) 2. The concentration of methane in landfill gas was assumed to e 50 percent y volume (500,000 ppmv). 3. Maximum predicted 24-hr and annual methane impacts were 2,647 and 308 mg/m 3, respectively. 4. Average concentration of hydrogen chloride, present in flare emissions, is calculated from stoichiometry as 39 ppmv. Percent of AAL Pass/ Fail Sample calculation for toluene, annual impact: Toluene Methane MW ppmv 308 mg/m 3 = µg/m 3 MW ,000 ppmv