Fischer-Tropsch Diesel from Solid Biomass

Transcription

1 Fischer-Tropsch Diesel from Solid Biomass The ECN Concept(s) for Large-Scale Syngas Production ThermoNET meeting, Helsingør, October 2003 Harold Boerrigter, Bram van der Drift Energy research Centre of the Netherlands (ECN) ECN Biomass (1) ECN Biomass ThermoNET meeting, Helsingør, October 2003 Content Development of gasification concepts Successfully demonstrated systems Large-scale production of liquid (FT) fuels Economic aspects The H 2 /CO ratio issue Conclusions & Outlook (2) ECN Biomass ThermoNET meeting, Helsingør, October 2003

2 Concept = Choice!! System Definition & Assumptions (1) Fischer-Tropsch diesel as liquid fuel - ultra clean and high quality fuel - applicable in current infrastructure/engines & future fuel cells FT-synthesis in the Netherlands (Rotterdam Harbour) - market for by-products: electricity, heat, and light FT products Large-scale centralised systems - optimised energy integration - economy-of-scale FT synthesis & upgrading (3) ECN Biomass ThermoNET meeting, Helsingør, October 2003 Concept = Choice!! System Definition & Assumptions (2) Feedstock: (clean) imported biomass - assumed future market price of 4 /GJ (~65 $/ton) Biomass import required to achieve targeted production of renewable fuels (in the Netherlands) High biomass-to-fuel efficiency required - to reduce cost of expensive biomass fuel - fuel cost is major cost-driver (~50%) Production of clean biosyngas is technical issue - syngas feedstock for many fuel and chemical synthesis (4) ECN Biomass ThermoNET meeting, Helsingør, October 2003

3 Gasification & Fischer-Tropsch Integrated system off-gas Biomass light product Electricity & Heat Green Diesel Gasification Gas Cleaning Fischer-Tropsch Synthesis CC (5) ECN Biomass ThermoNET meeting, Helsingør, October 2003 Fischer-Tropsch synthesis Specifications feed gas Impurity Removal level H 2S + COS + CS 2 < 1 ppmv NH 3 + HCN < 1 ppmv HCl + HBr + HF < 10 ppbv alkaline metals < 10 ppbv solids (soot, dust, ash) essentially completely organic compounds (tars) below dew point - class 2 (hetero atoms) < 1 ppmv class 2 tars: phenol, pyridine, thiophene organic compounds include also BTX (6) ECN Biomass ThermoNET meeting, Helsingør, October 2003

4 Gasification Concepts Requirements Clean and conditioned biosyngas: High efficiency to biosyngas Tars, NH 3, HCl, H 2 S, COS, alkalines, solids removed Maximum 15 vol% inert (nitrogen, CO 2, also: hydrocarbons) All chemical energy in H 2 and CO Ratio H 2 /CO = 2 (overall consumption ratio) bar (FT synthesis pressure) (7) ECN Biomass ThermoNET meeting, Helsingør, October 2003 Gasification Concept (1) CFB gasification + Tar cracker CFB Gasifier Tar Cracker 1300 C Wet Cleaning & Filters Gas Conditioning FT synthesis Oxygen/steam-blown CFB gasification Gasification pressure 20 bar - high electricity consumption for syngas compression Gas conditioning: - compressing from 20 to 40 bar -CO 2 removal -H 2 /CO ratio adjustment (8) ECN Biomass ThermoNET meeting, Helsingør, October 2003

5 Gasification Concept (2) EF gasification of pre-treated biomass Pre-treatment EF Gasifier Wet Cleaning & Filters Gas Conditioning FT synthesis Pre-treatment of solid biomass -pulverisation Oxygen-blown EF bar Gas conditioning: -CO 2 removal -H 2 /CO ratio adjustment (9) ECN Biomass ThermoNET meeting, Helsingør, October 2003 Gasification Concept (3) CFB gasification + OLGA + Reformer tars + BTX CFB Gasifier Tar Removal (OLGA) Wet Cleaning & Filters Reformer Gas Conditioning FT synthesis Oxygen-blown CFB bar Removal of tars & BTX and recycle to gasifier Reforming of hydrocarbons to H 2 and CO Gas conditioning: - compressing from 20 to 40 bar -CO 2 removal -H 2 /CO ratio adjustment (10) ECN Biomass ThermoNET meeting, Helsingør, October 2003

6 Three ECN concepts From paper to practice Successful demonstration of integrated gasification, gas cleaning, and FT synthesis systems (no conditioning) Low-temperature gasification + Tar cracker more than 650 h operation Oxygen/steam-blown fluidised bed gasification + OLGA EF gasification: issue is feeding - research focus on feeding of solid biomass (11) ECN Biomass ThermoNET meeting, Helsingør, October 2003 Integrated Test (1) Low-temperature gasification + Tar cracker off-gas oxygen Tar cracker Aqueous scrubber liquid product B wax product willow Low-temperature gasification A Compressor Fischer-Tropsch micro flow unit C char : gas analysis location Active carbon & ZnO filters Bottles --- Biosyngas production Gas cleaning FT synthesis --- First Production of FT-liquids from wood: December 2001 (12) ECN Biomass ThermoNET meeting, Helsingør, October 2003

7 Gas Compositions Destruction of tars and hydrocarbons Gas Raw biosyngas Cracked biosyngas FT feed gas CH 4 [vol%] C 2H 4 [ppmv] 5936 < 5 < 5 C 2H 6 [ppmv] 7359 < 5 < 5 BTX [ppmv] 1266 < 5 < 5 Tars [ppmv] +/- 50% < 10 < 10 NH 3 [ppmv] ~ H 2S [ppbv] ~ < 10 3 COS [ppbv] ~ CS 2 [ppbv] ~ 207 < 10 TOTAL [vol%] high-temperature tar cracker 2. wet scrubbers 3. active carbon en ZnO guard beds (Experimental data) (13) ECN Biomass ThermoNET meeting, Helsingør, October 2003 Integrated Test (2) BFB(O 2 ) Gasification + OLGA tar removal OLGA Aqueous scrubber off-gas liquid product wax product beech BFB oxygen/steam Compressor Fischer-Tropsch micro flow unit C oxygen steam : gas analysis location Active carbon & ZnO filters Bottles --- Biosyngas production Gas cleaning FT synthesis --- Production of FT-liquids from wood: March 2003 (14) ECN Biomass ThermoNET meeting, Helsingør, October 2003

8 Gas Compositions BFB(O 2 ) Gasification + OLGA tar removal Gas Raw product gas OLGA gas Scrubber gas FT feed gas CH 4 [vol%] C 2 H 4 [vol%] C 2 H 6 [vol%] C 2 H 2 [vol%] benzene [ppmv] toluene [ppmv] SPA tars [ppmv] 4114 < 10 < 10 < 10 NH 3 [ppmv] ~ HCl [ppmv] ~ 0.67 < 0.3 < 0.3 H 2 S [ppbv] ~ ~ < 10 COS [ppbv] ~ ~ CS 2 [ppbv] ~ ~ TOTAL [vol%] OLGA tar removal 2. wet scrubbers 3. active carbon en ZnO guard beds (Experimental data) (15) ECN Biomass ThermoNET meeting, Helsingør, October 2003 WOB BFB Thermal Converter 5 kw th Feed ~1 kg/h Oxygen/steam blown ~ 20 g/m n3 of tars (16) ECN Biomass ThermoNET meeting, Helsingør, October 2003

9 OLGA Unit Tar removal unit Oil-based Gas Washer ECN innovation Patented Concept Tar removal to dew point < -15 C (17) ECN Biomass ThermoNET meeting, Helsingør, October 2003 AGAF Advanced Gas Application Facility Processing of product gas Compressor - up to 60 bar Active carbon filter Sulphur removal filter (ZnO) (18) ECN Biomass ThermoNET meeting, Helsingør, October 2003

10 POTTOR Fischer-Tropsch Reactor Shell reactor - operated by ECN Fixed-bed reactor Cobalt-based catalyst (19) ECN Biomass ThermoNET meeting, Helsingør, October 2003 Overall Production System Large-scale biomass import A B,C F K 'green' diesel FT synthesis D E I J syngas cleaning/ conditioning electricity & heat biomass collection & pre-conversion A - biomass delivery at bcf B, E, G - storage & transhipment C - conversion into pyrolysis-oil D - truck transport to hub G H air separation gasification biomass conversion Transport of wood logs (alternative is conversion into pyrolysis oil) (20) ECN Biomass ThermoNET meeting, Helsingør, October 2003

11 Biomass Feed Cost 8000 MW biosyngas in Rotterdam harbour Cumulative production costs [euro/gj] euro/gj 2 euro/gj 0.5 euro/gj Technology: CFB + tar cracker, 70% gasification efficiency Contribution biomass feed to fuel costs: 4 /GJ = 49% 2 /GJ = 23% 0.5 /GJ = 11% Biomass land transport sea transport transhipment pre-treatment gasification Syngas FT diesel (21) ECN Biomass ThermoNET meeting, Helsingør, October 2003 Efficiency Biomass-to-Syngas 8000 MW biosyngas in Rotterdam harbour 16 Cumulative production costs [euro/gj] % 70% 85% Technology: CFB + tar cracker biomass costs: 4 /GJ 0 Biomass land transport sea transport transhipment pre-treatment gasification Syngas FT diesel (22) ECN Biomass ThermoNET meeting, Helsingør, October 2003

12 Production Routes 8000 MW biosyngas in Rotterdam harbour 16 Cumulative production costs [euro/gj] CFB gasification EF gasification Pyrolysis route Efficiencies CFB: 70% EF: 77% Oil: 70x81=57% 0 Biomass land transport sea transport transhipment pre-treatment gasification Syngas FT diesel (23) ECN Biomass ThermoNET meeting, Helsingør, October 2003 Perspectives of Green Diesel Comparison with green alternatives 30 Production price euro/gj Green diesel crude oil: $/barrel 0 Bio-diesel Bio-ethanol Green Diesel Fossil Diesel Real production prices; not subsidies, no tax incentives (24) ECN Biomass ThermoNET meeting, Helsingør, October 2003

13 Perspectives of Green Diesel Cost break-down price-at-pump Cumulative Costs of Diesel [ /L] ct 130 ct 110 ct 104 ct 83 ct VAT Exise Duty Fixed costs Off-refinery 63 ct fossil now 12 25% 50% 100% Projected FT diesel production costs: 12 /GJ Excise Duty exemption level small-scale demonstration (25) ECN Biomass ThermoNET meeting, Helsingør, October 2003 The H 2 /CO ratio issue What ratio is required? Net consumption ratio H 2 /CO = 2 for Fischer-Tropsch Feed ratio H 2 /CO < 2!! Additional pure H 2 required for: - make-up of H 2 shortage in FT reactor - FT product upgrading Separate H 2 /CO shift step is inevitable!! Why bother to influence H 2 /CO ratio in gasifier? (26) ECN Biomass ThermoNET meeting, Helsingør, October 2003

14 Effect on efficiency No shift: H 2 /CO = 2 in raw product gas biomass oxygen [m 3 n /h] 214 CFB 850 C steam [m 3 n /h] raw product gas H 2 /CO 2 /CO C Total Total steam steam [m [m 3 n 3 /h] n /h] product gas 2 Efficiency [LHV] % H 2 /CO 2 /CO CO 18.6 H CO CH C 2 H Oxygen/steam-blown CFB, wood, 10wt% moisture, input 1000 kg/h, heat loss 1%, steam 250 C, reference: 0.5 kg steam / m n 3 O 2 (27) ECN Biomass ThermoNET meeting, Helsingør, October 2003 Effect on efficiency Additional shift; minimal steam in gasifier biomass oxygen [m 3 n /h] 185 CFB 850 C steam [m 3 n /h] 92 1 raw product gas H 2 /CO 2 /CO C steam [m 3 n /h] 170 H 2 /CO shift 400 C Total Total steam steam [m [m 3 n 3 /h] n /h] product gas 2 Efficiency [LHV] % H 2 /CO 2 /CO CO 19.3 H CO CH C 2 H Oxygen/steam-blown CFB, wood, 10wt% moisture, input 1000 kg/h, heat loss 1%, steam 250 C, reference: 0.5 kg steam / m n 3 O 2 (28) ECN Biomass ThermoNET meeting, Helsingør, October 2003

15 Conclusions (1) Technical feasibility BG-FT systems proven Two tests for >500 h: 1. Low-temperature gasification + Tar cracker December Oxygen/steam BFB gasification + OLGA March 2003 wet cleaning with scrubber, compression, active carbon & ZnO filters, and FT synthesis unit Successful: Carbon-14 dating of FT products proves biomass origin No loss of catalyst activity and selectivity (29) ECN Biomass ThermoNET meeting, Helsingør, October 2003 Conclusions (2) ECN Biomass-to-Syngas concepts High conversion efficiencies are essential at expected costs of imported biomass (4 /GJ) Three feasible ECN Concepts for biosyngas production - CFB gasification + tar cracker - EF gasification of pre-treated biomass - CFB gasification + tar recycle + reformer Adjustment of H 2 /CO always by separate shift step At present, bio-fuels economically not feasible without tax incentives or subsidies (30) ECN Biomass Biomass Gasification Conference, Leipzig, 1-2 October 2003

16 Justification & Acknowledgement Parts of the presentation are based on results of the projects: Gas Cleaning for Biomass Gasification Fischer-Tropsch Systems by ECN, Shell, and Utrecht University. (Report in preparation) Large-scale Syngas Production from Imported Biomass by Shell, ECN, BTG, Ecofys, and Utrecht University. (Report in preparation) Entrained-flow gasification of solid biomass by ECN and Shell. (Project ongoing) Financial contribution: Agency for Research in Sustainable Energy (SDE) (31) ECN Biomass ThermoNET meeting, Helsingør, October 2003 More information Please contact: Dr. ir. Harold Boerrigter phone fax Publications can be found on: Visit also: Phyllis - internet database for biomass, coal, and residues: (32) ECN Biomass ThermoNET meeting, Helsingør, October 2003