1 / 33

Synthesis gas from Biomass in Millisecond Reactors

Synthesis gas from Biomass in Millisecond Reactors University of Minnesota – Dept. of Chemical Engineering & Materials Science Paul J. Dauenhauer , Lanny D. Schmidt. American Chemical Society National Meeting Catalysis and Chemistry for the Synthesis of Fuels, Chemicals, and Petrochemicals

yank
Download Presentation

Synthesis gas from Biomass in Millisecond Reactors

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Synthesis gas from Biomass in Millisecond Reactors University of Minnesota – Dept. of Chemical Engineering & Materials Science Paul J. Dauenhauer, Lanny D. Schmidt American Chemical Society National Meeting Catalysis and Chemistry for the Synthesis of Fuels, Chemicals, and Petrochemicals 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. What is biomass?

  5. 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) Fuel + Air Quartz Tube Heat Shields Catalyst Products Catalytic Partial Oxidation (CPOx)

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

  7. Partial Oxidation of CH4 CH4 + 2 O2 CO2 + 2 H2O Combustion CH4 + 1/2 O2 CO + 2 H2 Partial oxidation CO + H2O  CO2 + H2 Water gas shift CH4 + H2O  CO + 3 H2 Steam reforming

  8. Experimental Parameters & Results Experimental Parameters Experimental Results

  9. Partial Oxidation of CH4 - Effluent • Millisecond residence time • High Selectivity to H2 and CO • But what is happening inside?

  10. Partial Oxidation of CH4 – Profile

  11. Partial Oxidation of CH4 - Profile

  12. POx of CH4 + Steam Addition- Profile

  13. Partial Oxidation of Other Fuels • Volatile • Methane • Octane • up to Hexadecane • Methanol • Ethanol • Propanol • Ethylene Glycol • Glycerol • Ethyl Lactate • Nonvolatile • Glucose • Soy Oil • Cellulose • Starch • Lignin • Polyethylene • Raw Biomass

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

  15. 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

  16. 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)

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

  18. Partial Oxidation of CH4 3 mm

  19. Catalytic Reforming of Cellulose 3 mm

  20. Solids, Air Air 45 ppi, 5 wt% Rh, Ce T10 80 ppi, 5 wt% WC, 5 wt% Rh, Ce 45 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.

  21. Cellulose Reforming - Setup

  22. 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 Oxidation - Thermodynamics

  23. 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

  24. 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

  25. Cellulose Thermal Decomposition 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)

  26. 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

  27. Catalytic Reforming of Solids

  28. 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

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

  30. Catalytic Reforming of Polyethylene

  31. 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 • Remaining Issues • Ash handling • Mechanism / Modeling • High Pressure

  32. 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

More Related