1. COAL GASIFICATION GASIFICATION ONLY REASONABLE WHEN PLANT IS INTEGRATED SOME PROCESSES ARE COMMERCIAL H 2 S REMOVAL BY THE CLAUS PROCESS H 2 S + O 2 = H 2 O + SO 2 H 2 S + SO 2 = S + H 2 O

2. Energy Content Summary…. TypeBtu/SCF Producer Gas90-120 Water Gas341 Low-Btu150 Intermediate-Btu260-300 SNG950 Methane1054

3. Probable Uses…. Low-Btu gas –Local electrical power generation –Cannot be used for home or commercial heating Intermediate-Btu gas –Electrical power generation –Feed stock for chemicals –Town gas High-Btu gas…. Same as natural gas

7. Selection of a Gasifier Type of bed Operating pressure Slagging, non-slagging Lurgi (fixed bed, high P, non-slagging) Koppers-Totzek (entrained bed, low P, slagging) Wellman-Galusha (fixed, low P, non-slagging) Winkler (fluidized, low P, non-slagging)

10. Figure 7-6. Pipeline gas from coal via Lurgi pressure gasification. COAL PREPARATION OXYGEN-BLOWN COAL GASIFIERS SCRUBBING AND COOLING CRUDE GAS SHIFT CONVERSION H 2 O+CO=H 2 +CO 2 RECTISOL GAS PURIFICATION METHANATION 3H 2 +CO=CH 4 +H 2 O COMPRESSION AND DEHYDRATION ELEMENTAL SULFUR * 128 LTPD CO 2 H 2 S+CO 2 GAS LIQUOR 25,303 TPD @ 8,920 Btu/lb FEED COAL GAS LIQUOR SEPARATION AND EFFLUENT WATER TREATMENT PIPELINE GAS 290 MMSCFD @ 950 Btu/Scf RECLAIMED WATER TO PLANT USE NAPHTHA COAL TAR COAL OIL PHENOLS AMMONIA TOTAL LIQUIDS 8940 BBLS/day 155 tons/day OILY GAS LIQUOR SULFUR PLANT TARRY GAS LIQUOR N2N2 OXYGEN PLANT AIR COAL FINES STEAM OXYGEN STEAM AND POWER PLANT ELECTRIC POWER TO PLANT USE

14. Figure 7-11. The Texaco gasifier (also Shell, Eastman )

15. System for In-Situ Gasification of Coal From Wiser, 2000 Inject air and steam Produce low-Btu gas Chemical reactions

18. Financial Dilemma Synthetic natural gas cost ->$10.00/10 6 Btu Investment -75 x 10 12 Btu/year plant, 30 year life -$8 billion Benchmark is cost of oil and gas energy sources -Need a floor on the price of energy over a long time frame