Synthesis of DME and Gasoline from Biomass-Derived Synthesis Gas

Transcription

1 Synthesis of DME and Gasoline from Biomass-Derived Synthesis Gas 7 th ASIAN DME CONFERENCE November 16-18, 2011 Niigata, Japan Ulrich Arnold, Miriam Stiefel, Ruaa Ahmad, Herbert Lam, Manfred Döring Karlsruhe Institute of Technology (KIT), Institute of Catalysis Research and Technology (IKFT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen

2 Biofuels: An overview Direct gasification CO, H 2, CO 2, H 2 S, COS, NH 3 etc. Biodiesel Butanol ABE-Fermentation Transesterification of rapeseed oil with methanol Biomass Wastes etc. Fermentation of sugars and starch Degradation of (ligno)cellulose + fermentation Anaerobic digestion Hydrothermal gasification Fermentation Pure vegetable oil Squeezing or extraction Pyrolysis HydroThermal Upgrading (HTU) + HydroDeOxygenation (HDO) Pyrolyzate Gasification Hydrogen Methane Fischer-Tropsch-Synthesis (FT-Synthesis) Syngas Water gas shift reaction Methanization Conversion-of-Olefins-to-Distillate COD Direct synthesis Low temperature synthesis Direct synthesis Diesel Gasoline Olefins Dehydration Homologation Dimethylether Methanol Ethanol Methanol-To-Synfuel (MTS) Methanol-To-Gasoline (MTG) Methanol-To-Olefins (MTO) Reforming Isobutylene Hydrogen MTBE Isobutylene ETBE Ulrich Arnold

3 Related activities: GTL-, CTL- and BTL-processes for fuel production GTL = Gas-To-Liquid (Syngas from natural gas) - Motunui, New Zealand (Mobil) - Topsøe Integrated Gasoline Synthesis (TIGAS process), Texas, USA (Haldor Topsøe) - Mobil Olefin-To-Gasoline/Distillate process (MOGD) - Lurgi s Methanol-To-Synfuel process (MTS) - CAC plant, Freiberg, Germany CTL = Coal-To-Liquid (Syngas from coal) - Medicine Bow, Wyoming, USA (ExxonMobil) - Jincheng, Shanxi Province, China (JAM + Uhde) - Adams Fork Energy, Mingo County, West Virginia, USA (Uhde) BTL = Biomass-To-Liquid (Syngas from biomass) - CHEMREC process (production of dimethyl ether, DME): Chemrec, ETC, Volvo, Delphi, Haldor Topsøe, Preem, Total, SEA - Choren process (Fischer-Tropsch-Technology, FT) - French CEA project in Bure Saudron: CNIM group, Air Liquide, Choren, SNC Lavalin, Foster Wheeler-France, MSW Energy (FT) - BioTfueL project: Uhde Prenflo-PDQ-process, Total, IFP, French Atomic Energy Board, Sofiproteol (FT) - Güssing gasifier (woodchips), Oxford Catalysts (Velocys Inc., now part of the Oxford Catalysts Group), SGC Energia (Portugal), microreactor technology (FT)

4 The bioliq process at KIT Direct gasification CO, H, CO, H S, COS, NH etc Biodiesel Butanol ABE-Fermentation Transesterification of rapeseed oil with methanol Biomass Wastes etc. Fermentation of sugars and starch Degradation of (ligno)cellulose + fermentation Anaerobic digestion Hydrothermal gasification Fermentation Pure vegetable oil Squeezing or extraction H ydro T hermal U pgrading (HTU) + H ydro D e O xygenation (HDO) Pyrolysis Pyrolyzate bioliq I Gasification bioliq II Hydrogen Methane F ischer- T ropsch-synthesis (FT-Synthesis) bioliq IV bioliq III Syngas Water gas shift reaction Methanization COD Direct synthesis Low temperature synthesis Direct synthesis Diesel Gasoline Olefins Homologation Dimethylether Methanol Ethanol M ethanol- T o- S ynfuel (MTS) M ethanol- T o- G asoline (MTG) M ethanol- T o- O lefins (MTO) Reforming Isobutylene Hydrogen MTBE Isobutylene ETBE Ulrich Arnold

5 Investigated processes at KIT-IKFT Syngas (H 2 /CO 1) Direct Synthesis of DME Direct Synthesis of Ethanol 3 CO + 3 H 2 CH 3 OCH 3 + CO 2 3 CO + 3 H 2 C 2 H 5 OH + CO 2 Synthesis of Olefins from DME Synthesis of Gasoline from DME CH 3 OCH 3 C 2 H 4 + H 2 O n CH 3 OCH 3 (CH 2 ) 2n + n H 2 O

6 Focus on direct conversion of SYNGAS-TO-DME (STD) Syngas (H 2 /CO 1) Direct Synthesis of DME Direct Synthesis of Ethanol 3 CO + 3 H 2 CH 3 OCH 3 + CO 2 3 CO + 3 H 2 C 2 H 5 OH + CO 2 Synthesis of Olefins from DME Synthesis of Gasoline from DME CH 3 OCH 3 C 2 H 4 + H 2 O n CH 3 OCH 3 (CH 2 ) 2n + n H 2 O

7 Direct conversion of carbon monoxide-rich syngas to DME Three reactions take place simultaneously: Synthesis of methanol: 2 CO + 4 H 2 2 CH 3 OH DH R = kj/mol Dehydration of methanol: 2 CH 3 OH H 3 COCH 3 + H 2 O DH R = 23.5 kj/mol Water-gas shift reaction: CO + H 2 O H 2 + CO 2 DH R = 41.2 kj/mol Total reaction: 3 CO + 3 H 2 H 3 COCH 3 + CO 2 DH R = kj/mol

8 Laboratory plant for the STD process Fixed bed reactor: - D i = 1.6 cm - L = 30 cm - V = 60.3 cm 3 Catalyst: Bifunctional catalyst system comprising a methanol- and a dehydration-catalyst Reaction conditions: - p = 51 bar - T = C - GHSV = Nml/(min g Cat ) - Dilution: 70% inert gas

9 Typical results from the STD reaction H 2 /CO CO conversion (%) DME selectivity (%) CO 2 selectivity (%) MeOH selectivity (%) Pressure: 51 bar Reaction conditions: Temperature: 250 C Space velocity: Nml/(min g Cat ) Dilution: 70% inert gas M. Stiefel, R. Ahmad, U. Arnold, M. Döring, Fuel Process. Technol. 2011, 92,

10 CO conversion (%) Equilibrium conversion Influence of temperature and H 2 /CO ratio on DME synthesis H 2 /CO = 2.0 H 2 /CO = 1.0 H 2 /CO = p = 51 bar, 70% inert gas dilution, V total = 100 Nml/min T ( C) Large influence of temperature on CO conversion; Optimum range: C CO conversion increases with increasing H 2 content in the synthesis gas; Temperature dependence decreases with decreasing H 2 content

11 CO conversion (%) Influence of flow rate on DME synthesis H 2 /CO = 2.0 H 2 /CO = p = 51 bar, T = 250 C, 70% inert gas dilution H 2 /CO = V total (Nml/min) Almost maximum CO conversion at a flow rate of 50 ml/min at 250 C Increase of CO conversion by increase of residence time is independent of H 2 /CO ratio

12 CO conversion (%) Influence of syngas dilution on DME synthesis % % % H 2 /CO = 2.0 H 2 /CO = 1.0 H 2 /CO = 0.5 p = 51 bar, T = 250 C, V total = 100 Nml/min Ar dilution (%) The lower dilution the higher CO conversion The H 2 /CO ratio influences CO conversion: Maximum increase was observed at H 2 /CO = 1

13 CO conversion and DME selectivity (%) Influence of catalyst poisons on DME synthesis Reference; 146 ppm NH 3 ; 146 ppm H 2 S; 146 ppm HCl DME selectivity CO conversion T = 250 C, p = 51 bar, H 2 /CO = 1, V total = 167 Nml/min t (h) Strong deactivation by acidic catalyst poisons within 24 h CO conversion decreases but DME selectivity remains constant Influence of NH 3 is negligible within 24 h

14 CO conversion and DME selectivity (%) Long-term performance of the catalyst system in the absence and presence of CO Gas composition: H 2 = 35 ml N /min, CO = 35 ml N /min, N 2 = 20 ml N /min, Ar = 27 ml N /min H 2 = 35 ml N /min, CO = 35 ml N /min, N 2 = 10 ml N /min, Ar = 27.5 ml N /min, CO 2 = 9.5 ml N /min DME selectivity CO conversion p = 51 bar, T = 250 C, V total = 117 Nml/min t (h) Typical loss of activity within the first days but CO conversion remains in an acceptable range DME selectivity remains constant and high during three weeks

15 The bioliq process chain Gasification (bioliq II) Fast pyrolysis (bioliq I) Syngas Pyrolyzate Biomass HTHP gas cleaning + SYNGAS-TO-DME, STD (bioliq III) Methanol DME Olefins DME-TO-GASOLINE, DTG (bioliq IV) Gasoline

16 Dimensioning of the bioliq process bioliq I bioliq II bioliq IIIa+b bioliq IV Technology: Fast pyrolysis Entrained flow gasification bioliq IIIa: High Temperature High Pressure (HTHP) Syngas Cleaning bioliq IIIb: Syngas-To-DME (STD) DME-To-Gasoline (DTG) Product: Bio-slurry Synthesis gas DME Gasoline Dimensioning: 0.5 t/h dry biomass (2 MW) 1 t/h bio-slurry (5 MW) 150 kg/h DME 80 kg/h gasoline

17 Fuel production within the bioliq process Flow chart for DME and gasoline production (bioliq IIIb and IV) Cycle-Gas Compressor Water-Gas Shift Reactor CO 2 -Absorber DME-Reactor Gasoline-Reactor Rectification Column P-8 Gasoline Heavy Gasoline Product Separation Synthesis Gas Desorber Waste Gas CO 2 -Absorber

18 bioliq plant: View from southeast bioliq II bioliq I bioliq III bioliq IV Financial support from

19 bioliq plant: View from northeast bioliq II bioliq I bioliq III bioliq IV Cooperation between: and

20 Product options within the bioliq process Feed Reactor 1 Reactor 2 Reactor 3 Product Water-gas shift reaction MeOH/DME production MeOH catalyst DME catalyst Gasoline synthesis Syngas H 2 :CO = 1:1 + H MeOH +/ + + DME +/ Gasoline +/ (Modified catalyst) Kerosene

21 Why the methanol/dme pathway instead of a Fischer-Tropsch process? High flexibility: Production of various fuels and chemicals is possible High selectivity: No elaborate product separation technologies Processes are tunable to a large extent (catalysts, conditions, reactors etc.) Large optimization potential Comparison of Fischer-Tropsch with MTG Compound LT-FT Co Catalyst 220 C HT-FT Fe Catalyst 340 C Sources: Fischer-Tropsch Technology, (Ed.s: A. Steynberg, M. Dry), Elsevier, Amsterdam, MTG Methane Ethylene 0 4 Ethane Propylene Propane Butylenes Butane C5+ Gasoline Gasoil/Distillate Heavy Oil/Wax 46 5 Oxygenates

22 Conclusions Catalyst systems for the direct synthesis of DME in fixed bed reactors are mature Optimum reaction parameters are identified Higher H 2 content in syngas increases CO conversion High DME selectivity (60-68%) even at H 2 /CO 1 Main byproduct: CO 2 from the water-gas shift reaction Low amounts of methanol (< 2%) in the product mixture; Fast and almost complete dehydration of methanol Almost no further byproducts (< 0.1%); Traces of methane, propane, propene, butane CO 2 concentration should be low (< 5%); Otherwise significant decrease of CO conversion Major challenge: Up-scaling and reactor technology

23 Thank you!