K-3.i APPENDIX K-3. UPSTREAM EMISSION FACTORS

FROM COAL AND NATURAL GAS PRODUCTION

TABLE OF CONTENTS

TABLE

Table K-3.1 Estimated Upstream Emission Factors and Relative Percentages To Direct Power Plant Combustion Emissions . . . . . . . . . . . . . . . . . . . . . . . K-3.2K-3.1 APPENDIX K-3. UPSTREAM EMISSION FACTORS

FROM COAL AND NATURAL GAS PRODUCTION Tracking of pollutant emissions by NEMS-BRS is incomplete, with thorough treatment of some aspects and scant treatment of others. The approach is also somewhat different between emissions. Overall, carbon emissions are well covered because they are estimated based on elemental carbon released as CO 2 from all hydrocarbon combustion. However, some energy-use effects of proposed standards are not tracked by NEMS-BRS so their effects on carbon emissions are not counted. For example, the effect of lower residential electricity consumption on generation is estimated, but not the second order effect on energy consumed in coal transportation to power plants. In other words, the amount of energy used to perform the upstream processes in coal and natural gas production is not linked to the downstream consumption of these fuels. For this reason, while total carbon emissions are counted, changes due to proposed standards are not. According to M.A. DeLuchi, the amount of energy used to mine and clean the coal is minimal, amounting to less than 1% of the energy available in the coal. The amount of energy required to transport the coal using trains, trucks, and pipelines is approximately 0.156 EJ/yr (0.148 Quads/yr) as estimated for the year 2020. 1 Based on the AEO99energy consumption of coal from electric generation, this corresponds to 0.7% of the total energy required by electric generators. For natural gas production, the amount of energy used to transport natural gas to the end-use consumer is 3.5% of the total natural gas produced and made available to end-use customers as estimated for the year 2000. For extraction of crude oil, the relative percentage is only 2.8%. Thus, the upstream losses are small relative to the total amount of energy embodied in the coal, oil, and natural gas and, therefore, changes due to proposed standards are also likely to be small. NEMS-BRS tracks only NO xand SO 2 emissions from power generation. Sources of these emissions that may be affected by proposed standards are therefore missed. Two notable sources of NO xand SO 2 emissions not considered are household emissions from the combustion of natural gas, liquefied petroleum gas (LPG), and heating fuel oil and emissions associated with fuel extraction and delivery to the point of combustion. This analysis considers two uncounted emissions from coal and natural gas production and delivery, SO 2 and NO x . These emissions include those due to the mining of coal or extraction of natural gas, the physical processes involved in preparing or cleaning the fossil fuel, and the transportation of the fuel from the mine to the power plant. Household combustion effects of proposed standards are explicitly included in the appliance energy-efficiency standards analysis and the methods used are described in Appendix K-2. Studies addressing upstream emissions are very limited. Thus, the reliability of the exact measurements can be easily criticized. The values presented herre are only intended to provide a coarse estimate of the magnitude of upstream emissions not accounted for in NEMS-BRS. In general, emissions from mining, cleaning, or transporting fossil fuels are small compared to the emissions that result from their combustion.K-3.2 Upstream emissions estimates for carbon and NO x are taken from a thorough study done byM.A. DeLuchi at Argonne National Laboratory in 1993. DeLuchi provides estimates of full fuelcycle emissions factors for emissions of CO 2 , methane (CH 4 ), carbon monoxide (CO), non-methane organic compounds (NMOC), and NO x from coal and natural gas production. The emission factor for SO 2 is taken from the Environmental Protection Agency (EPA) AP-42. 2 This source notes that coal cleaning is the primary source for upstream SO 2 emissions from coal production, so the emission factor for SO 2 only reflects the coal cleaning process. Transportation is not addressed in EPA’s study. Emission factor estimates and corresponding percentage contributions of the upstream emissions relative to power plant emissions are shown in Table K-3.1 for carbon, SO 2 , and NO x from coal and natural gas production. The relative percentage to power plant emissions is provided so an estimate of upstream emission savings based on the savings from the power plant could be easily estimated. The values shown in Table K-3.1 represent emissions from upstream processes as mass (g) per deliverable energy to end-use consumers.

Table K-3.1 Estimated Upstream Emission Factors and Relative Percentages To Direct Power Plant Combustion Emissions Coal Natural Gas Emission

Factor ( g/GJ) % of Combustion

Emissions Emission Factor ( g/GJ) % of Combustion

Emissions Carbon 2222 2.7 5456 11.9

SO 2 29.2 0.9 0 0 NO x 41.7 5.8 153 40.0 DeLuchi’s analysis reveals that upstream processes in coal production relative to power plant emissions account for 5.8% of NO xand 2.7% of carbon. The AP-42 indicates that less than one percent of SO 2 emissions result upstream relative to those from coal power plant emissions. Upstream coal processes, therefore, account for at most 6% of relative power plant emissions for carbon, SO 2 , and NO x . For natural gas production, the upstream SO 2 emissions are negligible. The upstream emissions from NO x , however, are quite significant, accounting for 40.0% of emissions relative to those from the power plant. Total natural gas combustion NO x emissions from the power plant are only half those from coal, while emissions upstream processes are four times those of coal. Carbon emissions are nearly 12% of power plant emissions with an emission factor of 5456 g/GJ ofdeliverable energy; however, as noted above, changes to these emissions are counted by NEMSBRS.K-3.3 Relative to the entire fuel cycle, DeLuchi estimates that approximately 8% by mass of all emissions from coal production are due to mining, preparation, and transport from the mine to the plant. Transportation emissions include those resulting from the use of fuel by the modes of transportation used to move the fuel from the site of extraction to fuel production facilities. For natural gas production, 14% of total emissions are estimated to result from upstream processes. Based on Table K-3.1, this higher loss factor in natural gas production is likely due to the higher NO x contribution. Thus, emissions factors and their relation to power plant emissions are provided to reveal the relatively small proportion of energy losses attributable to upstream processes. With the exception of NO xemissions from natural gas production, all emissions are less than 12% of power plant emissions.K-3.4 REFERENCES 1. DeLuchi, M. A., Emissions of Greenhouse Gases from the Use of Transportation Fuels and Electricity, Volume 2: Appendixes A-S, November , 1993, Argonne National Laboratory. Argonne, IL. Report No. ANL/ESD/TM-22-Vol.2. 2. U.S. Environmental Protection Agency, Compilation of Air Pollutant Emission Factors, AP42, Fifth Edition, Volume I: Stationary Point and Area Sources, Chapter 11, Mineral Products Industry, 1995. November. < http://www.epa.gov/ttn/chief/ap42c11.html >