Breaking the Barriers to Lignocellulosic Biofuels: Liquid-phase catalytic processing of sugars and bio-oils. oils. Thrust Area #3

Transcription

1 Breaking the Barriers to Lignocellulosic Biofuels: Liquid-phase catalytic processing of sugars and bio-oils oils Thrust Area #3

2 verview of Liquid Processing 200 Liquid-phase ydrogenation ydrogenolysis Super-critical water gasification Vapor-phase Pressure / atm Dehydration ydrolysis Liquefaction Petrochemical Processes 50 Aqueous- Phase Reforming Isomerization Aldol- Condensation xidation Vapor-phase Reforming Pyrolysis Gasification Temperature / K

3 glyceraldehyde Alkanes +C a polysaccharide isomerization -15 kcal/mol lactic acid reforming & FT synthesis -30 kcal/mol Thermo of Selected Rxns - 2 n dehydrogenation 15 kcal/mol glycerol kcal/mol kcal/mol glucose C-Chydrogenolysis C- hydrogenolysis dehydration/hydrogenation propanediol hydrolysis reforming 80 kcal/mol 3C kcal/mol synthesisgas -10 kcal/mol sorbitol kcal/mol hydrogenation +6 2 oxidation +1/2 2-50kcal/mol DFF 6C reforming 150 kcal/mol dehydration + 2 MF DM-TF hydrogenation -20kcal/mol DMF hydrogenation -35 kcal/mol aldol condensation +Acetone -10 kcal/mol B-MF + 2 hydrogenation kcal/mol +2 2 C-hydrogenolysis dehydrationhydrogenation kcal/mol C-hydrogenolysis dehydrationhydrogenation kcal/mol + 2

4 Reaction Classes ydrolysis Dehydration Reforming C-C hydrogenolysis C- hydrogenolysis ydrogenation C-C coupling (e.g., aldol condensation) Isomerization Selective oxidation Water gas-shift

5 Examples of Routes for Biomass Conversion to ydrogen, Fuels and Chemicals

6 Production of ydrogen from Biomass-derived Carbohydrates

7 -C-C (metal) 2 Selectivity Challenges -C-C- * * -C-C- * * 2 2 C-C cleavage (metal) C- cleavage (metal) 2 Dehydration/ ydrogenation (metal,support,solution) Water-gas Shift 2,C synthesis (metal) gas -C-C- (alcohols) 2 2,C 2 Methanation, Fischer-Tropsch reactions (metal) (metal) Dehydrogenation/ Rearrangement (metal,support,solution) (metal) -C-C- (organic acids) Alkanes 2,C 2, 2

8 Liquid Fuels from Carbohydrates Sugars Ethanol All processes involve removal of - groups, requiring: External source of 2 (producing 2 ), e.g., by APR Alkanes Dimethylfuran Internal production of C 2

9 Conversion of Glycerol to C: 2 Mixtures: Low-Temperature Production of Synthesis Gas

10 Glycerol Reactivity (350 o C) Conversion to Gas Phase (%) Pt/Mg-Zr Time on stream (h) Pt/C Pt/Ce 2 -Zr 2 Pt/Al 2 3 Pt/Zr 2 2 TF (min -1 ) Pt/Mg-Zr 2 Pt/Al 2 3 Pt/C Pt/Ce 2 -Zr Time on stream (h) Pt/Zr 2

11 Sources of Glycerol By-product waste-stream from biodiesel production, i.e., trans-esterification of triglycerides, leading to ~80 wt% glycerol in water Glucose fermentation, leading to 25 wt% glycerol in water (compared to 5% for ethanol) Catalytic hydrogenolysis of xylitol and sorbitol (C 5 and C 6 sugar-alcohols)

12 Coupling of Glycerol Conversion with Fischer-Tropsch Synthesis: Glycerol to Liquid Alkanes

13 Coupling Gasification & FT Synthesis 1 C C (C+22 C8 16+2) (C + C ) (C+ C + ) kcal/mol -81 kcal/mol -10 kcal/mol -7 kcal/mol C C C +0.76C C kcal/mol -354 kcal/mol Δ 1 Δ c (Gly) = 24% Δ 5 Δ c (Gly) = -4%

14 Reforming Catalysts Fischer-Tropsch synthesis typically carried out at K (and bar) eat must flow from FT to reforming catalyst (Temperature for FT > T for reforming) Pt/C not active below ~573 K Θ C increases as T decreases Additives needed to lower adsorption energy of C on Pt Surface alloys may be useful!!

15 Glycerol Conversion: Pt-Ru & Pt-Re Glycerol conversion (%) 90 C/C 2 PtRu:300 o C PtRe:250 o C PtRu:275 o C PtRe 40 2 /C PtRe:225 o C PtRu Molar ratio Time on stream (h) Time on stream (h) Soares, Simonetti, Dumesic, Angewandte Chemie 45, 3982 (2006).

16 Examples of Production of Value- added Chemicals from Carbohydrates: Glycerol hydrogenolysis to PG (also dehydration-hydrogenation) hydrogenation) Glucose conversion to LA (retro-aldol aldol-rearrangement)

17 Example of Production of Value- added Chemicals from Carbohydrates: MF* from exoses * ydroxymethylfurfural 2 C C

18 Sleeping Giant* MF and its oxidation product 2,5-furandicarboxylic acid are so called sleeping giants in the field of intermediate chemicals from regrowing resources. 2 C C * M. Bicker, J. irth and. Vogel, Green Chemistry, 2003.

19 Dehydration Reaction Pathways Fragmentation Products Additional Dehydration Products Rehydration Products Levulinic Acid Formic Acid C C C D-Fructose β-pyranose C 2 C 2 C 2 C 2 Acyclic Intermediates C C C -2 C -2 C2-2 2 C - 2 MF aq MForg C 2 Reversion Products Fructofuranosyl Intermediates Soluble Polymers and Insoluble umins Condensation Products

20 Approach to Achieve igh Selectivity for MF Bi-phasic reactor system for selective conversion of fructose to MF using Cl as catalyst and chemical modifiers to increase yield. 2 C 2 C MForg MFaq C C rganic Layer: Extracting solvent: MIBK Modifier: 2-butanol Aqueous Layer: Fructose Cl catalyst Modifiers 2 C C 2 D-Fructose + 2 C MF C 1. Fructose is converted to MF 2. Aqueous layer modifiers slow down unwanted parallel reactions 3. Extracting solvent extracts MF and prevents MF degradation

21 MF selectivity vs Extraction Ratio

22 General ideas Accelerated cellulose conversion to glucose via chemical catalysis Direct Cellulose conversion to MF via chemical catalysis Alternative reusable solvent systems, e.g. ionic liquids, for bio-processing Direct conversion of lignin to refinery intermediates Direct conversion of lignin to chemical products New methods for lignin structure determination in support of catalytic cleavage Conrad Zhang

23 Using MF to produce liquid fuels (dimethylfuran)

24 Solubilities (g/liter) Lowsolubility in water igh solubility in water igh solubility in water alpha-glucose C 2 monosaccharides beta-glucose C 2 Fructose C 2 C 2 Lowsolubility in water polysaccharides C 2 C 2 C 2 Starch: 1-4 linkages of alpha-glucose C 2 C 2 C 2 Cellulose: 1-4 linkages of beta-glucose

25 Boiling Points ( o C) 68 o C 73 o C 91 o C 93 o C 140 o C 158 o C 165 o C 213 o C 291 o C 262 o C alpha-glucose 372 o C C 2 monosaccharides beta-glucose C 2 Fructose C o C C 2 polysaccharides C 2 C 2 C 2 Starch: 1-4 linkages of alpha-glucose C 2 C 2 C 2 Cellulose: 1-4 linkages of beta-glucose

26 Strategy: Sugars to Liquid Fuels Boiling Point RN g/l 15 g/l 12 g/l Water Solubility dehydration Fructose C K C K C K g/l 2.3 g/l MF 564 K 645 K 535 K 431 K 413 K 486 K 438 K hydrogenolysis 364 K 366 K Dimethylfuran xygen Content 346 K 341 K

27 MF DMF Fructose 2 C C 2 Chemical Intermediates xygen Removal Fuels exane Carbohydrates Solvents Volatility DMF Energy Density DMF Fuel range Water Solubility DMF