Synthesis Gas Purification in Gasification to Ammonia/Urea Plants

Transcription

1 Synthesis Gas Purification in Gasification to Ammonia/Urea Plants GASIFICATION TECHNOLOGIES CONFERENCE October 4-6, 2004 Washington D.C Dave Heaven, John Mak Fluor Enterprises, Inc., Aliso Viejo, California, Dan Kubek, Mike Clark, Curtis Sharp UOP LLC, Des Plaines, Illinois

2 Outline Conversion of low valued refinery residue and coke to syngas using gasification is proven and viable for ammonia production Case studies were conducted to evaluate today s syngas purification technologies for ammonia and urea production Compare the process differences between Selexol + PSA to Rectisol + N2 Wash process. Compare their capital and operating costs The process configuration was adopted in the Coffeyville Resources Ammonia Fertilizer Complex. Operating data of the gas purification unit are reviewed

3 Gas Purification Technologies Technology 1 Rectisol Methanol solvent operates at very low temperatures. Methanol solvent is H 2 S selective. N 2 Wash Fractionation process operates at cryogenic temperatures Technology 2 Selexol DMPEG solvent operates at mildly refrigerated or ambient temperatures. Selexol is H 2 S selective PSA Adsorption process operates at ambient temperatures

4 Case Studies Case 1 - Selexol/ PSA Case 2 - Selexol/PSA + CO 2 production Case 3 - Rectisol/N 2 Wash Case 4 - Rectisol/N 2 Wash + CO 2 production

5 SELEXOL/PSA PROCESS AIR SEPARATION PLANT LP N2 HP N2 H2 PSA AMMONIA PLANT 2000 MTD AMMONIA HP O2 STEAM TREATED GAS CW QUENCH GASIFIERS SYNGAS SCRUBBING CO SHIFT / HEAT RECOVERY SELEXOL WASTE GAS ACID GAS TAILGAS RECYCLE 2590 MTD COAL COAL GRINDING/ SLURRY PREP RAW WATER SULFUR PLANT SULFUR

6 SELEXOL DESIGN WITH CO2 PRODUCTION 900PSIG 170 PSIG 430 PSIG

7 CO2 PURIFICATION

8 RECTISOL / N2 WASH PROCESS AIR SEPARATION PLANT LP N2 HP N2 H2 N2 WASH AMMONIA PLANT 2000 MTD AMMONIA HP O2 STEAM TREATED GAS RECYCLE CO2 PURGE CW QUENCH GASIFIERS SYNGAS SCRUBBING CO SHIFT / HEAT RECOVERY RECTISOL WASTE GAS ACID GAS TAILGAS RECYCLE 2450 MTD COAL COAL GRINDING/ SLURRY PREP RAW WATER SULFUR PLANT SULFUR

9 Selexol/PSA vs Rectisol/N2 Wash Selexol/ PSA Partially remove CO 2 0 to 40 F (CS Material) Regen by Steam Syngas contains ppm levels of inerts CO 2 product at high pressure Rectisol/ N 2 Wash Removes all CO 2-80 F (SS Material) Regen by N 2 stripping Very pure syngas product CO 2 product at low pressure

10 Capital Cost Comparison No CO2 Production With CO2 Production Cost ($1,000) Case 1 Case 3 Case 2 Case 4 Selexol/PSA Rectisol/N2 Wash Selexol/PSA Rectisol/N2 Wash Selexol Unit 22,862 N / A 22,862 N / A PSA Unit 34,342 N / A 34,342 N / A Rectisol /N2 Wash Units N / A 100,800 N / A 100,800 Balance of Plant (BOP*) 430, , , ,990 Incremental Capital Costs Base 43, ,596 Incremental BOP Costs Base (18,060) 3,934 (13,090) Incremental Overall Plant Capital Costs Base 25,536 3,934 30,506 *BOP Cost exclude ammonia synthesis

11 Operating Cost Comparison No CO2 Production With CO2 Production Cost ($1,000) Case 1 Case 3 Case 2 Case 4 Gas Purification & BOP Selexol/PSA Rectisol/N2 Wash Selexol/PSA Rectisol/N2 Wash Fixed Operating Costs 19,430 19,900 19,512 20,174 Utility & Feed & Chemicals 52,980 54,360 56,625 59,118 Total Annual Oper. Cost 72,410 74,260 76,137 79,292 Incremental Oper. Cost: Fixed Operating Costs Base Utility & Feed & Chemicals Base 1,380 3,645 6,138 Annual Operating Cost Base 1,850 3,727 6,882

12 Study Results Selexol + PSA syngas is more economical than Rectisol + N 2 Wash in syngas purification, both in capital and operating costs Same conclusions apply to different gasification technologies, plant capacities and types of feedstocks The Selexol + PSA design were applied in the syngas purification process of Coffeyville Resources Coffeyville, Gasification Ammonia Complex for ammonia and urea production

13 Coffeyville Resources Coffeyville, Kansas, USA Gasification Ammonia Complex UOP

14 Coffeyville Resources Ammonia Fertilizer Complex Feedstock: 45 MT/H petroleum coke Commercial Operation: July 2000 Process Licensors Gasification: ChevronTexaco Gas Purification Block: - Acid Gas Removal: Selexol -H 2 Purification: Polybed PSA Sulfur: Black & Veatch Pritchard Air Separation: BOC Ammonia / UAN: Ammonia Casale / Weatherly UOP

15 Coffeyville Block Flow Diagram Air NH 3 Product Air Separation Unit N 2 Ammonia Synthesis UAN Plant UAN Product O2 High Purity Hydrogen Purified CO 2 Polybed PSA Raw H 2 CO 2 Purification CO 2 Vent Tail Gas Raw CO 2 Quench Gasification Syngas Scrubbing CO Shift & Gas Cooling Selexol 2-stage Petroleum Coke UOP Technologies Claus Claus Plant Unit Acid Gas UOP

16 Coffeyville Resources Gasification Ammonia / UAN Complex UOP

17 Coffeyville Resources SELEXOL and POLYBED PSA Units UOP

18 Coffeyville Resources SELEXOL Unit UOP

19 Coffeyville Resources POLYBED PSA Unit UOP

20 Coffeyville Operations Summary Operated since July Convert pet coke to urea and ammonia using UOP Gas Purification Block SELEXOL + PSA SELEXOL Products PSA Product >90 MM SCFD of raw H 2 H 2 Purity >99.3% < 1 ppm H 2 S < 5 ppm CO < 1 ppm COS CO 2 below Det.. Limits >10.6 MM SCFD of CO 2 >93% of CO 2 Removed Acid Gas >44 mole % H 2 S UOP

21 Coffeyville Operations Summary Operated since July 2000 Highly Reliable No Solvent-Related Issues No reclaiming Minimal Solvent Losses Meets All Product Specifications H 2 Purity to PSA CO 2 Purity for Urea Production H 2 S in Acid Gas UOP

22 Conclusions Due to high natural gas prices, production of fertilizer products from refinery residue and coal is economically attractive Coffeyville Resources has proven that UOP SELEXOL plus POLYBED PSA processes are viable for fertilizer production Fluor and UOP have proven Gas Purification Portfolio for: Separation of H 2 S and CO 2 Separation of CO 2 and H 2 Purification of H 2 UOP

23 Synthesis Gas Purification In Gasification Based Ammonia/Urea Plants