Conversion Technologies Chemical and Catalytical Processing: Gas phase route

Transcription

1 1 st Brazil-U.S. Biofuels Short Course: Providing Interdisciplinary Education in Biofuels Technology July 27 - August 7, 2009 University of Sao Paulo, Sao Paulo, Brazil Conversion Technologies Chemical and Catalytical Processing: Gas phase route Ricardo Reis Soares School of Chemical Engineering Federal University of Uberlandia rrsoares@ufu.br

2 Uberlandia?! Where is it?

3 utline bjectives General Background Glycerol as a block molecule Synthesis gas by low gas-phase glycerol aqueous solution reforming at low temperature Coupling the reforming and WGS for H 2 production Coupling the reforming and FTS for liquid fuel production Partial Conclusions Direct Sugar/Polyol Conversion New Biorefinery approach Integration of Reforming and Deoxygenation reactions C-C coupling reactions Partial Conclusions Conclusions Acknowledgements

4 Main bjective Chemical and Catalytical processing Platform Prof. Ulf Lecture Cellulosic derivatives Sugars This Lecture: Gas phase route Dr. Yuryi Lecture: HMF-based route Biomass Platform 1: Ethanol Platform 2: Thermochemical Fuels Chemicals/Commodities Energy Plastics and Polymers Dr. Lawrence Russo (U.S. Department of Energy) Seminar (Monday/27-July)

5 Heuristics for Chemical and Catalytical Processing Biomass Limit the number of processing steps Less operations = lower cost Use renewable reagents/solvents Minimize solvent use Use concentrated feeds Efficient product separation Spontaneous separation of hydrophobic products Cascades of flow reactors Facilitate transport between processing steps Integrated Processes Energy Balance & Thermodynamics Find good catalyst(s)

6 utline bjective General Background Glycerol as a block molecule Synthesis gas by low gas-phase glycerol aqueous solution reforming at low temperature Coupling the reforming and WGS for H 2 production Coupling the reforming and FTS for liquid fuel production Partial Conclusions Direct Sugar/Polyol Conversion New Biorefinery approach Integration of Reforming and Deoxygenation reactions C-C coupling reactions Partial Conclusions Conclusions Acknowledgements

7 Current proven processes using biomass feedstock Vegetable oils and animal fats Transesterification Fermentation (1) Cellulosic Carbohydrates Aqueous Ethanol (8 wt %) Distillation ($$$) Waste Glycerol Aqueous Glycerol (25-80 wt %) Fuel-Grade Ethanol Biodiesel Low Temperature Gas-Phase Processing Hydrogen GAL Syngas C + H 2 Water-Gas Shift Reaction Methanol Methanol Synthesis Fischer-Tropsch Synthesis (FTS) Chemicals Liquid Hydrocarbons (diesel, light naphta) Di-Methyl Ether (DME) (1) C. S. Gong, J. X. Du, N. J. Cao, G. T. Tsao, Appl. Biochem. Biotech. 2000, 84-86,

8 Vegetable oils and animal fats Transesterification Waste Glycerol Biomass Feedstock Sorbitol (3) Aqueous Glycerol (25-80 wt %) (2) Prof. Ulf class Sugars (Hexoses) Biodiesel Low Temperature Gas-Phase Processing Hydrogen GAL Syngas C + H 2 Water-Gas Shift Reaction Methanol Methanol Synthesis Fischer-Tropsch Synthesis (FTS) Chemicals Liquid Hydrocarbons (diesel, light naphta) Di-Methyl Ether (DME) (2) Gallezot et al., Appl. Catal., A: General, v 331, p , 2007 (3) E. Tronconi et al.; Chem. Eng. Sci., 47(9-11), ,1992

9 Catalytic testing units - UFU

10 Catalyst Screening (T = 623 K, P = 1 bar, and 30 wt% Glycerol) Conversion to Ga as Phase (%) Pt/C H TF (m min -1 ) Pt/Ce 2 -Zr 2 Pt/Ce 2 -Zr 2 Pt/Al 2 3 Pt/Zr 2 Pt/Mg-Zr 2 Time on stream (h) Pt/C Pt/Mg-Zr 2 Pt/Al 2 3 Time on stream (h) Pt/Zr 2 From R. R. Soares, D. A. Simonetti, J. A. Dumesic, Angewandte Chemie-International Edition, 2006, 45,

11 4 Catalyst Screening (T = 623 K, P = 1 bar, and 30 wt% Glycerol) (H 2 /C) mo olar ratio Pt/Al 2 3 Pt/Ce 2 -Zr 2 Pt/C Pt/Zr 2 C 3 H 8 3 3C + 4H 2 [H 2 /C] = 1.33 nly Glycerol decomposition takes place WGS takes place on the oxide-supported catalysts Time on stream (h) The WGS sites are blocked. Pt/Mg-Zr 2 From R. R. Soares, D. A. Simonetti, J. A. Dumesic, Angewandte Chemie-International Edition, 2006, 45,

12 18 16 Catalyst Screening (T = 623 K, P = 1 bar, and 30 wt% Glycerol) (C 2 TF/ H 2 TF) X It suggests that one of the modes of catalyst deactivation is the coke formation by dehydration reactions Time on stream (h) From R. R. Soares, D. A. Simonetti, J. A. Dumesic, Angewandte Chemie-International Edition, 2006, 45,

13 Pt/C stability at different reaction conditions Conversion to Ga as Phase (%) wt%, 1 bar 50 wt%, 1 bar 30 wt%, 20 bar Time (h) Molar Ra atio wt%, 1 bar 30 wt%, 1 bar 30 wt%, 20 bar C/C 2 H 2 /C Time (h) From R. R. Soares, D. A. Simonetti, J. A. Dumesic, Angewandte Chemie-International Edition, 2006, 45,

14 Results from Initial Kinetics Measurements Pt/C (inert support) showed The best stability High activity and selectivity Support plays important role: Water-gas shift Deactivation However, for fuel and chemicals production: Can we carry out two reactions at same conditions (T,P) over either consecutive beds or in separate reactors?

15 What do we need to do? Find a catalyst that works in the T and P range of FT What is the problem? Pt/C shows low activity below 573 K and under pressure Θ C increases as T decreases (and P increases) What is a potential solution? Additive to weaken adsorption of C on Pt

16 DFT : C Adsorption on Near Surface Alloys Greeley & Mavrikakis, Catal. Today 111,, 52 (2006) Pt Good candidates! Pt/Ru Pt/Re Large BE gap Cu is not a good catalyst

17 Bimetallic catalyst screening (P = 1 bar and 30 wt% Glycerol) Glycerol Reactivity and Selectivity over Pt-Me/C bimetallic catalysts K 573K 548K 100 Gas phase carbon selectivity at 623K Conversion to gas pha ase (%) Gas phase carbon selec ctivity (%) Alkanes C2 C 0 Pt PtRu PtRe PtFe PtCu PtSn PtIr PtCo PtNi PtRh Pts Catalyst 0 Pt PtRu PtRe PtFe PtCu PtSn PtIr PtCo PtNi PtRh Pts Catalyst From E. L. Kunkes, R. R. Soares, D. A. Simonetti, and J. A. Dumesic,; Applied Catalysis B, 90 (2009)

18 Bimetallic catalyst screening (P = 1 bar and 30 wt% Glycerol) Apparent Activation Energies measurements from Pt-Me/C bimetallic catalysts 6,5 6,0 5,5 E a =35 kj/mol ln C TF (min -1 ) 5,0 4,5 4,0 Pt PtCu PtRu PtRe E a =43 kj/mol E a =84 kj/mol 3,5 E a =93 kj/mol 3,0 0, , , , , , /T (1/K) Reaction mechanism may proceed differently on the Ru and Re promoted catalyst From E. L. Kunkes, R. R. Soares, D. A. Simonetti, and J. A. Dumesic,; Applied Catalysis B, 90 (2009)

19 Glycerol Conversion to Synthesis Gas (Pt-Re/C with 30% Glycerol at 548 K and 8.3 bar) C/C 2 H 2 /C

20 Vegetable oils and animal fats Transesterification Advances in Biofuel production Fermentation Cellulosic Carbohydrates Aqueous Ethanol (8 wt %) Aqueous Ethanol Distillation (8 wt ($$$) %) Waste Glycerol Aqueous Glycerol (25-80 wt %) Fuel-Grade Ethanol Biodiesel Low Temperature Gas-Phase Processing Coupling: Syngas formation and FTS Hydrogen GAL Syngas C + H 2 Water-Gas Shift Reaction Methanol Methanol Synthesis Fischer-Tropsch Synthesis (FTS) Chemicals Liquid Hydrocarbons (diesel, light naphta) Di-Methyl Ether (DME)

21 Advances in Biofuel production Coupling Gasification & FT Synthesis Advantage: Heat integration 1 3C+4H C H 2.24C+4.48H 0.28C H +2.24H 0.28(C H +H C H ) 0.76(C+H C +H ) C H C H C H +0.76C +1.48H 3C +4H kcal/mol -81 kcal/mol -10 kcal/mol -7 kcal/mol -15 kcal/mol -354 kcal/mol From R. R. Soares, D. A. Simonetti, J. A. Dumesic, Angewandte Chemie-International Edition, 2006, 45,

22 Heat Integration Glycerol/Water Glycerol Reformer Heat in = 242 kcal/mol Heat out = 99 kcal/mol Net heat = 143 kcal/mol Fischer-Tropsch Converter Synthesis gas Synthesis gas & water T = 275 o C P = 10 bar 30 wt% Glycerol H c = 354 kcal/mol Process heat 149 kcal/mol 24 kcal/mol 173 kcal/mol Water Combustion gases Water E out E in = 2.4 Liquid alkanes

23 Advances in Biofuel production Two-bed system : Glycerol + H 2 (30-80 wt%) Syngas formation & FTS X C = 30% Pt-Re/C 0,1 0,01 T = 548 K P tot = 8 bar H 2 :C = 2 S C5+ S CH4 S C2 C5+ = 38% S CH4 = 15% C2 = 4.5% C+H 2 + H 2 + xygenates 548 K 8 bar S /n cn 1E-3 1E-4 1E-5 α=0.8 Ru/Ti 2 1E n Liquid Fuel This method may allow for economic operation of a small-scale scale FT reactor by having a heat-integrated catalytic process. From D. A. Simonetti, J Rass-Hansen, E. L. Kunkes, R. R. Soares, and J. A. Dumesic, Green Chemistry,9, 2007,

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25 Vegetable oils and animal fats Transesterification Advances in Biofuel production Fermentation Cellulosic Carbohydrates Aqueous Ethanol (8 wt %) Aqueous Ethanol Distillation (8 wt ($$$) %) Waste Glycerol Aqueous Glycerol (25-80 wt %) Fuel-Grade Ethanol Biodiesel Low Temperature Gas-Phase Processing Coupling: Syngas formation and WGS Hydrogen GAL Syngas C + H 2 Water-Gas Shift Reaction Methanol Methanol Synthesis Fischer-Tropsch Synthesis (FTS) Chemicals Liquid Hydrocarbons (diesel, light naphta) Di-Methyl Ether (DME)

26 Advantages: Heat Integration Net energy (kj / mol.glycerol) Reaction at 573 K with C combustion without C combustion Net energy = H (reforming) + H (glyc.+h 2 gasification) - H (products combustion) A maximum energy balance at 60 wt% glycerol A positive energy balance for glycerol concentration higher than 18 wt% wt% of glycerol in aqueous solution From E. L. Kunkes, R. R. Soares, D. A. Simonetti, and J. A. Dumesic,; Applied Catalysis B, 90 (2009)

27 Results Two-beds system : Syngas formation & WGS Conversion to gas phase co onversion (%) wt% glycerol conversion at 573K 60 Conversion H 2 /C H2 /C Pt-Re/C C+H 2 +H 2 Glycerol + H 2 (80 wt%) 573 K Pt/CeZr Time on stream (hr) H 2 /C From E. L. Kunkes, R. R. Soares, D. A. Simonetti, and J. A. Dumesic,; Applied Catalysis B, 90 (2009)

28 Results Two-beds system : Syngas formation & WGS wt% glycerol conversion at 573K Glycerol + H 2 (30 wt%) Conversion to gas phase con nversion (%) Conversion H 2 /C H2 /C Pt-Re/C C+H 2 +H 2 Pt/CeZr 573 K Time on stream (hr) H 2 /C 2 From E. L. Kunkes, R. R. Soares, D. A. Simonetti, and J. A. Dumesic,; Applied Catalysis B, 90 (2009)

29 Results Summary of the results of the coupled reactions Glycerol (wt %) Carbon Conversion (%) Alkane Selectivity (%) H 2 /C ratio H 2 Yield (%)

30 Partial Conclusions We showed that liquid fuels and chemicals can be produced from glycerol via a two-step gas-phase process that involves the catalytic conversion of glycerol to H 2 and C combined with subsequent water-gas shift and Fischer- Tropsch synthesis. The experimental results validated the Rational Design approach of the catalyst selection by using DFT simulations. This two-step process serves as an energy-efficient efficient alternative to current biomass-based based processes to produce fuels and chemicals. We showed that valuable chemicals can be produced from glycerol via one-step aqueous-phase reforming.

31 utline bjectives General Background Glycerol as a block molecule Synthesis gas by low gas-phase glycerol aqueous solution reforming at low temperature Coupling the reforming and WGS for H 2 production Coupling the reforming and FTS for liquid fuel production Partial Conclusions Direct Sugar/Polyol Conversion New Biorefinery approach Integration of Reforming and Deoxygenation reactions C-C coupling reactions Partial Conclusions Conclusions Acknowledgements E. L. Kunkes et al.; SCIENCE, 2008 Slides from E.L. Kunkes presented at 2008 AICHe

32 Integration of reforming and deoxygenation 60 wt% Sorbitol C 6 H H 2 C 2 10 wt % Pt-Re/C 503 K 18 bar H 2, C x, Alkanes Acids H C 6 H 14 6 Alcohols 13H 2 C 4 -C 6 H 70-80% of H 2 from reforming is used in de-oxygenation C 6 H y z + H 2 Heterocyclics Ketones H 2 H 2 rearrangement H 2 H 2 cyclization H H H H Water Pt-Re chemistry H Sugar/Polyol H H H E.L. Kunkes et al. Science (2008) H H * H 2 C -H cleavage H H 2 H 2 H H * * C - cleavage H H H H * * * * H H 2 +C 2 water-gas shift H 2 H 2 C -C cleavage * * * Slides from E.L. Kunkes presented at 2008 AICHe C C C

33 Some facts Intermediate pressures and temperatures Provide the greatest yields of monofunctional products 60 wt% sorbitol conversion at 503K and 18 bar 1 kg of organic phase (sorb_503_18) for every 3.5 kg of sorbitol 70 % of maximum possible efficiency (complete balance between reforming and deoxygantion) Sorb_503_18 retains 65% of the energy in sorbitol feed Monofucntional hydrocarbons can be used directly Solvents, chemical intermediates, fuels and fuel additives C 6 is the limit? (C-C coupling processes) Gasoline additives (aromatics) Diesel and Jet fuels C 8 -C 12 E.L. Kunkes et al. Science (2008) Slides from E.L. Kunkes presented at 2008 AICHe

34 Coupling of alkenes C-C C coupling Reactions R' H R" H + 500K R' R" + H 2 Dehydration H + R + R' R 523K R' Coupling R + R' + R" R H + 623K R" + H 2 Aromatization R' R R + H + 623K Alkylation E.L. Kunkes et al. Science (2008) Slides from E.L. Kunkes presented at 2008 AICHe

35 Hydrogenation-Aromatization Sorb_503_18 (Active components) H H Ru/C 423K 50 bar H 2 H_Sorb_503_18 H H H 2 HZSM-5 673K 1 bar Aromatics and olefins 40 % conversion of Sorb_503_18 into fuel grade aromatics 29.4% C4 6.8% C % Benzene 14.3% Toluene 11.0% Xylenes and Ethylbenzene E.L. Kunkes et al. Science (2008) % C3 1.1% C % C3-6 Substituted benzene

36 C-C C coupling Reactions (contd.) Aldol condensation-dehydration-hydrogenation R H - + H + + R' R R' R R' H H 2 Pd/Cu H K With H 2 co-feed Ketonization of carboxylic acids R R' R' + R H + /H - R' R H H + H 2 + C 2 E.L. Kunkes et al. Science (2008) Slides from E.L. Kunkes presented at 2008 AICHe

37 Vapor phase aldol condensation Sorb_503_18 (Active components) H CuMg 10 Al 7 x 5 bar 573K H 2 Condensation products Pt/NbP 4 40 bar 523K H 2 Singly-branched C 8 -C 12 alkanes H 2 H 2 H Acid Neutralization Required acids deactivate basic catalyst! 6.2% C 8 7.9% C % C 10 ~40% conversion to C 8 -C % C 11 ~85% conversion of 2-ketones 28.8% C 6 8.2% C 12 E.L. Kunkes et al. Science (2008) Slides from E.L. Kunkes presented at 2008 AICHe 25.8% C 4-5

38 Ketonization and Condensation 30.5% C 6 Gluc_483_18 (Active components) H H 7.7% C 7 H 2 C 2 Glucose-derived 100 % conversion organic: to C 7 -C35% 11 acids Ketonized Gluc_483_18 (Active components) Pd/CeZr x 5 bar 623K H 2 CeZr x H 20 bar 623K % C % C 9 H 10.1% C 7 C 7 -C 12 Linear and branched ketones 57% C 7+ products 12.5% 8.7% C C % C % C % C 4-5 E.L. Kunkes et al. Science (2008) % C % C % C % C % C % C 12+ Slides from E.L. Kunkes presented at 2008 AICHe

39 Partial Conclusions Strategy: Remove oxygen but retain some functionality Sugar/polyol conversion involves a balance between C-C C and C- cleavage reactions Endothermic C-C C cleavage (reforming) provides H 2 Exothermic C- cleavage (deoxygenation deoxygenation) consumes H 2 PtRe/C catalyzes both reactions (heat and H 2 integration in single reactor) Intermediate temperatures and pressures achieve maximum yield of mono-functional products High temperatures and pressures alkanes (non-functional) Low temperatures/pressures oxygenated aq. products Targeted C-C C coupling reactions yield fuel grade products E.L. Kunkes et al. Science (2008) Slides from E.L. Kunkes presented at 2008 AICHe

40 Conclusion : Chemical and Catalytic Platform will be an alternative for future biorefineries Fermentation BIETHANL Bagasse Trans and/or esterification of vegetable, edible oils and fatty acids Biodiesel Pyrolysis BIMASS Sugars Glycose Fructose Lactose Arabinose Sucrose Xylose Starch Polyol (Glicerol and Sorbitol) Syngas (C + H 2 ) Bio-oil ENERGY (Fuels) Acid hydrolysis (hemi) and Cellulose Biomass Residues (as bagasse) Chemicals

41 Acknowledgements U.S. Department of Energy (DE), ffice of Basic Energy Sciences, Chemical Sciences Division CAPES and UW for post-doctoral grants PETRBRAS and CBMM for FT financial support FAPEMIG and PETRBRAS for UFU Biofuel Research FULBRIGHT (THAIS CSER et al.) Catalytic Bio-Reforming Team Dante A Simonetti Prof. James A Dumesic Edward L Kunkes

42 Thank you! Questions?

43 The Reaction Network H H H 2 H 2 H 2 H H C-C Cleavage *CH x H2 C WGS H 2 C 2 H H H 2 Metal Methanation H 2 F-T Synthesis H 2 C- Cleavage (Dehydration) H 2 H H H H H H H H H H H H H H (Alkane precursors) C-C C Cleavage C- Cleavage H 2 H 2 CH 4 C 2 H 6