FCC Propylene Production - PDF Free Download

Higher Severity Propylene Design Operating Flexibility Envelope Gasoline Higher Throughput If Higher Propylene Production is Attractive, There Are Revamp Options to Get You There UOP 4706A-02

FCC Unit Design & Operating Envelopes Propylene Yield, wt-% FF 20 10 5 Maximum Gasoline f (Rx T, P P, C/O, P T ) Gasoline Propylene + + LPG Aromatics 60 30 Gasoline Yield, wt-% FF What is the Optimal Propylene Yield? UOP 4706A-06

FCC Propylene Production Targets C 3 = Wt-% Yield on Fresh Feed Unit A E J P R S T Average Initial RFQ ------ 20.0 20.0 18.0 21.0 15.0 16.0 18.3 Final Design Selected 10.5 8.0 10.5 15.1 11.3 11.1 10.0 10.9 UOP 4706A-12

Process Variables Response Study Existing Reactor Constrained on Cyclone Inlet Percent, or Pressure (psig), or Temperature (T-1000 o F) 100 1300 90 1250 80 1200 70 1150 60 1100 50 1050 40 1000 30 950 20 900 10 850 0 800 30 40 50 60 70 80 Hydrotreated Feed, kbsd C 3 = Production, tonnes/day Reactor Pressure Reactor Temp (T-1000 1000 F) C 3 = wt-% % FF C 3 = Production Tonnes/day UOP 4706A-08

Process Variables Response Study Existing Reactor Constrained on Cyclone Inlet Percent, or Pressure (psig), or Temperature (T-1000 o F) 100 1300 90 1250 80 1200 70 1150 60 1100 50 1050 40 1000 30 950 20 900 10 850 0 800 30 40 50 60 70 80 Hydrotreated Feed, kbsd C 3 = Production, tonnes/day Maximum Severity Costs About 50% Capacity UOP 4706A-09

FCC Operating Modes C 2 = C 3 = C 4 = Wt-% % Yield on Fresh Feed Gasoline 0.83 4.76 6.62 Gasoline + LPG 1.42 10.50 9.62 Propylene +Aromatics 7.10 18.10 9.83 Gasoline 54.36 43.94 35.21 UOP 4706A-10

FCC Operating Modes Wt-% % Yield on Fresh Feed Gasoline Gasoline + LPG Propylene +Aromatics Total Delta Aromatics 34.70 44.00 54.70 +58 % Benzene 0.46 0.59 1.29 +280 % Optimizing the Overall Complex LP is Critical to Defining the Optimum FCC Operating Envelope UOP 4706A-11

Product Recovery System Design Review Which Type of Recovery System is Best? Compression Based Cold Box,, or Absorption Based Gas Concentration UOP 4706A-13

Product Recovery System Designs Compression Based Cold Box C 1 / C 2 / C 3 Main Column C 4 / C 5 Absorption Based C 1 / C 2 Main Column Absorber/ Stripper C 3 / C 4 / C 5 UOP 4706A-14

Product Recovery System Design Review Product Recovery System Case Study Feed Rate: 50,000 BPSD Ethylene yield: Propylene yield: Gasoline yield: Propylene recovery: Ethylene recovery: 9 wt-% FF 23 wt-% FF 19 wt-% FF 98 wt-% FF 98 wt-% FF UOP 4706A-15

Recovery System Costs EEC (MM$) 300 250 200 150 100 50 0 Capital Costs Gas Con Cold Box Gas Con Utility Costs Cold Box 9000 8000 7000 6000 5000 4000 3000 2000 1000 0 US Dollars per Hour Product Recovery Refrigeration Main Column BF Water HP Steam MP Steam LP Steam Cooling Water Shaft Work UOP 4706A-16

Propylene Recovery in the Primary Absorber Propylene Recovery (%) 100 80 60 40 20 % C 3 = Recovery in Primary Absorber 0 20 40 60 Debutanizer Bottoms Recycle (1000 BBL/day) High Absorber Efficiency Beats the Cost of Compression UOP 4706A-17

Utilities and Annualized Capital Costs Costs (MM $/yr) 200 180 160 140 120 100 80 60 40 20 Utility Annualized Capital 0 Gas Con Cold Box Gas Con Cold Box Natural Gas Price: CMAI $5.9 / MM Btu July 2006 $10.7 / MM Btu September 2005 UOP 4706A-19

Utilities and Annualized Capital Costs Costs (MM $/yr) 200 180 160 140 120 100 80 60 40 20 Utility Annualized Capital $5.9 / MM Btu $10.7 / MM Btu 0 Gas Con Cold Box Gas Con Cold Box Higher Absorption Efficiency Beats Compression Costs Across a Wide Range of Utility Values UOP 4706A-20

U.S. Propylene Focus 100% 80% C 3 = TPA 60% 40% 20% 0% US Gulf Coast %C 3 = to Polymer CMAI Data 2003 4.8 wt-% FF US East Coast US West Coast Rest of US %C 3 = to LPG or Alkylation UOP 4706A-21

Propylene and Natural Gas Values $/Tonne 1400 1200 1000 800 600 400 200 Polymer Grade C 3 = Refinery Grade C 3 = Natural Gas $215 $900 0 98 99 00 01 02 03 04 05 06 C 3 = Slippage to Fuel Gas has Become Costly UOP 4706A-20

Propylene Product Downgrade C 3 + in Dry Gas (mol-%) C 3 = Loss to Dry Gas (tonne/day) C 3 = Value Lost ($/day) 3% 7% 10.2 24.8 $0 5% 17.4 $6,480 $13,140 @ $900 / tonne: Product Downgrade = $4,600,000 / yr Current Economics do Justify Recovery Projects UOP 4706A-26

Gas Con Recovery Constraints Fractionator & Absorber Capacities - High capacity trays or packing - Additional in-line or parallel absorber Lean Oil Circulation & Cooling Temperature - Additional lean oil circulation - Chilled water system HP Condenser Duty -Stripper overhead routed directly to primary absorber bottoms Off-loads the high pressure condenser Better feed conditioning to primary absorber UOP 4706A-27

Gas Con Capacity Constraints Wet Gas Compressor Capacity - Increased reactor pressure (possible re-rate) rate) Higher suction head to off-set lower MW Lower ACFM to accommodate cyclone velocity constraints - Re-rate the compressor Heat Integration with the FCC Main Fractionator - Alternative heat integration configurations But Can the Same Gas Con Handle a Step- Change in Operating Severity? UOP 4706A-27

Absorption Based Gas Con Flexibiliity Operating Mode Gasoline: C 3 = + Aromatics: Wild Naphtha 0.8 X 0.2 X Stabilized Naphtha 0.2 X 0.8 X Absorber/ Stripper C 1 / C 2 Main Column X Same Equipment Capacity for Both Modes! Same Equipment C / 3 C / C 4 5 Capacity for Both Modes! UOP 4706A-18

C 3= Alkylate & Regular Gasoline Values $/Tonne 1400 1200 1000 800 600 400 200 C 3= to Alkylate Regular Gasoline $450 0 98 99 00 01 02 03 04 05 06 The Value Gap Between C 3 = to Alkylate and Gasoline is One Incentive to Increase FCC Severity UOP 4706A-19

Revamp Constraint Commercial Example Alleviated Constraints Feed Rate: +58 % Propylene Yield: 9.9 wt-% FF Propylene Rec.: 97 wt-% FF C 3 + in Fuel Gas: < 3.0 mol-% FF UOP has Revamped Over 500 k-bpsd k of Existing FCC Capacity for C 3= in the 7 to 10 wt-% FF FF UOP 4706A-29

Summary: There are current economic drivers for FCC s s to produce more propylene. Economics analyses suggest that optimal propylene production is well below what the technology is capable of producing. New unit constructions support that 10 to 11 wt-% propylene production is an economic optimum for most. UOP can help move existing refiners move higher on the propylene production curve within major capital equipment constraints. UOP 4706A-30

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