1. SO 2 Emissions Kristin Burford 23/April/01 ME 449A: Sustainable Air Quality

2. Table of Contents n Purpose and Methods n EPA Emission Preparation n Major Sources of SO 2 – Coal Combustion – Oil Combustion – Gas Combustion – Petroleum Refining – Non-Road Diesel

3. Purpose and Methods n Determine how the SO 2 emissions were calculated by the EPA – Find out general emission calculation information – Determine major sources of SO 2 according to 1996 Trends Data (Link to Trends) – Explore the specific factors which influence the the SO 2 emissions for the major sources

4. EPA Emission Preparation n How are emissions determined? – Two factors: source information and emission factors General Equation : Emission = Emission Factor*Quality of Consumed Fuel n emission factors found in AP42 (link to AP42) n qualities of consumed fuel include amount of fuel, energy produced, % of precursor element in the fuel n In this study, the focus is on emission factors and how they are calculated – EPA rates the emission factors from A (best) to E according to how well the calculated emission correlates with the actual emission

5. Major Sources of SO 2

6. Coal Combustion n About 60-70% of SO 2 Emissions n Coal Rank: – anthracite - more C, less volatile, rare – bituminous - less C & more volatile than anthracite, most common – sub-bituminous - lower S, more volatile & moisture than bituminous n Uncontrolled emission factors (lbs SO 2 /ton coal): – 38*%S - bituminousRating: A – 35*%S - sub-bituminousRating: A – 39*%S - anthraciteRating: B n Have shown good correlation between calculated and actual emissions

7. Oil Combustion About 10-20% of total SO 2 emissions Uncontrolled emission factor (lbs SO 2 /10 3 gal): 0.98(MW SO2 /MW S )(%S/100)x oil density x 1000 (oil gallons) Rating: A n Variables: – 98% conversion assumed – %S – oil density n assumed 7 for distillate and 8 for residual n actual range 6.97- 7.03 (distillate) 7.95-8.17 (residual)

8. Gas Combustion n 5-10% of total SO 2 emissions n Uncontrolled emission factor: (S grains/100 ft 3 )(lb/7000 grains)(ft 3 /1000 gal)(2 lb SO 2 /lb S) = 0.6 lbs SO 2 /10 6 std. ft 3 (scft) gas Rating: A n Assumes 100% conversion of fuel S to SO 2 and 2000 grains of S/10 6 scft. n Can convert emission factor to energy units using the average heating value of the gas (good approximation?) n Actual emissions not measured n Conservative, assume all S --> SO 2

9. Petroleum Refining n No background documentation for emission factors n Includes conversion of crude oil to over 2500 different products n Multiple Processes – Separation – Conversion – Treating – Feedstock and product handling – Auxiliary processes n The emission factors presented in the AP42 have large ranges, probably depending on the purity of the product

10. Non-Road Diesel n Not included in AP-42 online n Emissions based on : travel & rate of emission n SO 2 based on 0.25% S in fuel (can be adjusted)

11. The End Questions? Comments? Suggestions?