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Millisecond Catalytic Conversion of Nonvolatile Carbohydrates for Sustainable Fuels

Millisecond Catalytic Conversion of Nonvolatile Carbohydrates for Sustainable Fuels University of Minnesota – Dept. of Chemical Engineering & Materials Science Paul J. Dauenhauer , Bradon J. Dreyer, Josh L. Colby, Lanny D. Schmidt. American Chemical Society National Meeting

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Millisecond Catalytic Conversion of Nonvolatile Carbohydrates for Sustainable Fuels

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  1. Millisecond Catalytic Conversion of Nonvolatile Carbohydrates for Sustainable Fuels University of Minnesota – Dept. of Chemical Engineering & Materials Science Paul J. Dauenhauer, Bradon J. Dreyer, Josh L. Colby, Lanny D. Schmidt American Chemical Society National Meeting Division of Fuel Chemistry Biofuels: Renewable Liquid Fuels & Chemicals from Biomass August 20, 2007

  2. Biomass Processing Ethanol, Lactic Acid Alkanes Enzymes Sugars Alkanes Methanol DME Ethanol Power Heat H2, CO Crops (Food, Energy) Wastes (Agriculture, Municipal)

  3. Lignin (24%) Hemicellulose (21%) Xylan, Galactan, Arabinan, Mannan) Extractives (9.5%) Uronic & acetyl acids Cellulose (45%) glucan Ash (0.5%) Yellow - Ca, Mg, K Biomass – Aspen Trees

  4. Fuel and O2 enter at the top Valuable chemicals produced: syngas (H2 & CO), olefins, oxygenates, etc. Exothermic process Runs auto-thermally Short contact times (Milliseconds) Catalytic Partial Oxidation (CPOx) Fuel + Air Quartz Tube Heat Shields Catalyst Products

  5. “Catalytic Fire” Fuel + O2CO + H2 + HEAT Catalyst

  6. Fuel Injector Plug Air Heating Tape Static Mixer Upstream Temperature Catalyst Sample Port Incinerator Backface Temperature Experimental Setup

  7. Experimental Parameters & Results Experimental Parameters Experimental Results

  8. Carbohydrates – CPOx of Glycerol • Higher S/C ratios decrease operating temperature • Conversion >99% up to C/O=1.6 • RhCe/γ-Al2O3/α-Al2O3

  9. Carbohydrates – CPOx of Glycerol S/C = 4.5 • Higher S/C ratios increase H2 selectivity • Maximum SH(H2)~90% for all three carbohydrates S/C = 2.0 S/C = 0

  10. Carbohydrates α Glycerol C3H8O3 or C3(H2O)3H2 Boiling Point ~ 300 °C α-D-(+)-Glucose C6H12O6 or C6(H2O)6 Dehydration Polymerization (C6H10O5 monomers) α(1-4) – linkage (starches) highly branched coiled β(1-4) – linkage (cellulose) no branching linear (crystalline & amorphous)

  11. O2 C1 – C4 Volatile Compounds Reform Nonvolatile Fuels How can we reform larger carbohydrates? Pyrolysis www.nrel.gov

  12. Partial Oxidation of CH4 3 mm

  13. Catalytic Reforming of Cellulose 3 mm

  14. Solids, Air Air 45 ppi, 5 wt% Rh, Ce T10 80 ppi, 5 wt% WC, 5 wt% Rh, Ce 80 ppi, 5wt% WC, 5 wt% Rh, Ce T30 80 ppi, blank Cellulose Reforming - Setup N.J. Degenstein, R. Subramanian, L.D. Schmidt, Applied Catalysis A: General305 (2006) 146-159.

  15. Cellulose Reforming - Setup

  16. 7 0 % CO C o n d e n s i n g V a p o r s O b s e r v e d 6 0 % 5 0 % C / O 1 . 0 _ 4 0 % 0 . 9 H or S CH4 3 0 % 0 . 8 C S 0 . 7 2 0 % H2 Operating Temperatures 1 0 % 0 % 2 0 0 3 0 0 4 0 0 5 0 0 6 0 0 7 0 0 8 0 0 9 0 0 1 0 0 0 1 1 0 0 1 2 0 0 T e m p e r a t u r e , 3 0 m m ( d e g C ) Cellulose Thermodynamics

  17. Catalytic Reforming of Cellulose Always operate predicting no carbon. P.J. Dauenhauer, B.J. Dreyer, N.J. Degenstein, L.D. Schmidt, Accepted to Angewandte Chemie

  18. Catalytic Reforming of Cellulose Produce equilibrium synthesis gas. Higher C/O = more H2 + CO Less than 1% methane At C/O < 1.0, no oxygenates P.J. Dauenhauer, B.J. Dreyer, N.J. Degenstein, L.D. Schmidt, Accepted to Angewandte Chemie

  19. Catalytic Reforming of Cellulose Gases (ex. CO, H2) O2 Rh 800 °C Cellulose Volatile Organics O2 500 °C X Char 200 °C Process: Millisecond CatalyticProcessing Process: Char Production (~minutes) Process: Gasification Process: Fast Pyrolysis (~1 sec)

  20. Catalytic Reforming of Cellulose Solid particles contact a hot surface Particles form volatile organic compounds (VOC) VOCs undergo exothermic surface oxidation Heat is conducted upward to drive particle decomposition Catalyst C/O: 0.9 0.7

  21. Catalytic Reforming of Solids

  22. Cellulose Reforming – Better Syngas Fuel + O2 + H2O(g) • Desire a pure stream of syngas (H2 / CO ~ 2) • Partially oxidize with pure O2 rather than air • Reduce convection • Reduce syngas dilution • Preheat feed gases • Operate fuel rich • Reduce syngas dilution • Add steam • Adjust syngas ratio (H2/CO) to ~2 Quartz Tube Catalyst Heat Shield Products

  23. Cellulose Reforming – Steam Addition C/O ■ 0.6 ● 0.7 ▼ 0.8 ▲ 0.9 Feed Gas N2 79% 59% 19% 39%

  24. Comparison to Gasification • Faster – 10 to 100X • Possibly smaller (more portable) • Faster, more flexible start-up • Cleaner – Catalyst breaks down volatile organics • Possibly eliminates downstream clean-up stages • Provides WGS capabilities • Can add steam to adjust H2/CO ratio for desired output • Possibly eliminates separate shift stage

  25. Acknowledgments Ethanol reforming Tupy, Rennard, Dauenhauer Olefins from biodiesel Dreyer Ethyl lactate and ester reforming Rennard, Dauenhauer Soy oil reforming Dreyer, Dauenhauer Solids reforming Dauenhauer, Dreyer, Degenstein, Colby Methanol, ammonia and alkane synthesis Bitsch-Larsen, Huberty, Walker Ash Management Tupy, Rennard Professor Lanny D. Schmidt Dr. Raimund Horn Professor Ulrike Tschirner Dr. Raul Caretta

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