NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy operated by the Alliance for

Transcription

1 Upgrading of Bio-oil oil for Fuel Production 13 th Annual Green Chemistry & Engineering Conference Luc Moens, Ph.D June 25, 2009 NREL is a national laboratory of the U.S. Department of Energy ffice of Energy Efficiency and Renewable Energy operated by the Alliance for Sustainable Energy, LLC

2 Topics What is bio-oil? Lignocellulosic biomass composition Bio-oil properties chemical composition Upgrading Future R&D: catalytic pyrolysis Innovation for ur Energy Future

3 From Biomass to Bio-oil: Pyrolysis T ( C) 900 Fischer-Tropsch process Gasification 600 C + H 2 syngas Pyrolysis Bio-oiloil??? 300 Liquid Fuels Biomass Innovation for ur Energy Future

4 From Biomass to Bio-oil: Pyrolysis T ( C) Bio-oiloil 900 Pyrolysis Biomass Fast pyrolysis no oxygen C rapid heating (>1000 C/s) short residence times (1-2 s) Innovation for ur Energy Future

5 From Biomass to Bio-oil: Pyrolysis T ( C) Bio-oiloil 900 Pyrolysis Biomass Fast pyrolysis ~75 wt% liquid product yield (25 wt% = char + gas) can be transported / stored conversion into fuels & chemicals Innovation for ur Energy Future

6 Biomass feedstocks Ag residues Willow Forest residues Hybrid poplar Switch grass Innovation for ur Energy Future

7 Lignocellulosic Biomass Lignin 15% - 25% complex aromatic structure resists biochemical conversion Hemicellulose 23% - 32% carbohydrate polymer C 5 and C 6 sugars (xylose-based) Cellulose 38% - 50% glucose polymer (C 6 ) H 3 C H H CH 3 H H H CH 3 H CH 3 CH CH 3 3 H 3 C H H H H H H H H H H H H H H H CH 3 H H H H H H H H H H H CH 3 CH 3 H H H H H 3 C H H H H H CH CH 3 3 H H H H H H H H H H H H H H H H H H H H H 3 C H H H H H H H H H H CH 3 H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H Innovation for ur Energy Future

8 Fast Pyrolysis Bio-oil Density ~ 1.2 kg/l Combustible (HHV~18 MJ/kg) 5% methanol addition Contains Homogenization 20-30% H 2 Partly miscible with water Non-miscible with hydrocarbons Highly acidic: ph ~ 2.5 (corrosive!) Strong phenolic odor Innovation for ur Energy Future

9 Fast Pyrolysis Bio-oil basis) High degree of oxygenation 5% methanol addition Homogenization C 40-48%, H 7-8%, 44-52% (wet C 53-57%, H 7-7.5%, 36-40% (dry basis) (cfr. heavy fuel oil - C 85%; H 11%; 1%) Innovation for ur Energy Future

10 Fast Pyrolysis Bio-oil Bio-oil changes properties during storage increase in viscosity rate = exp(-9659/t) cp/day decreased volatility phase separation formation of gums and deposits 5% methanol addition Homogenization Instability is caused by thermochemical processes that lead to cross-linking of C= compounds (Diebold, J.P.; Czernik, S., Energy Fuels 1997, 11, 108) Innovation for ur Energy Future

11 Bio-oil: chemical composition Fresh bio-oil is a homogeneous emulsion of > 300 organic compounds Wt % of bio-oil C1 (formic acid, methanol) 5-10 C1-C4 aldehydes, glyoxal, hydroxyketones, carboxylic acids C5-C6 furfuraldehydes, furanones, pyranones Anhydrosugars (levoglucosan) 6-10 Carbohydrate oligomers 5-10 Phenolics 6-15 Pyrolytic lignin (oligomeric phenolics) unidentified ~ 20 cellulose derived lignin derived Radlein, D., The Production of Chemicals from Fast Pyrolysis Bio-oils, in Fast Pyrolysis of Biomass; A Handbook Innovation for ur Energy Future

12 Bio-oil properties Bio-oil contains ~ 20% H 2 [H 2 ] 30% phase separation Bio-oil + water Phase separation 5% methanol addition Homogenization asmaa, A.; Czernik, S., Energy & Fuels, 1999, 13, Innovation for ur Energy Future

13 From Bio-oil to Liquid Transportation Fuels Petroleum Refinery Liquid Fuels Diesel Jet fuel Gasoline Diesel Bio-oiloil Technical barriers High acidity (corrosive) High oxygen content (~40%) (too high for hydrotreatment/hydrocracking) Innovation for ur Energy Future

14 From Bio-oil to Liquid Transportation Fuels Petroleum Refinery Liquid Fuels Diesel Jet fuel Gasoline Diesel Bio-oiloil Upgrading through chemical modification neutralization of acids stabilization (no cross-linking by C= groups) Innovation for ur Energy Future

15 Bio-oil Neutralization & Stabilization R H R 1 H H + R R 1 H 2 acid alcohol ester R H 2 R 1 H H + R 1 R R 1 H 2 aldehyde alcohol acetal Disadvantages Reactions are equilibrium-limited 20 wt% residual acid Excess water from crude bio-oil (20-30%) and condensation reaction Acid catalyst required Stoichiometric amount of RH needed (high cost!) Moens, L.; Black, S. K.; Myers M. D.; Czernik, S. Energy Fuels 2009, 23, 2695 Innovation for ur Energy Future

16 Bio-oil Hydroprocessing (H 2 ) Review: Elliott D. C. Energy Fuels 2007, 21, 1792 Commercial catalysts: NiMo, CoMo, precious metals High T / P conditions achieve hydrodeoxygenation Compatible with petroleum refinery infrastructure Range of hydrocarbon products (gasoline-type): aromatics cycloalkanes nly lignin-derived phenolics are relevant (only ~25% of biomass) use of added H 2 cost is an issue Innovation for ur Energy Future

17 Lignocellulosic Biomass Lignin 15% - 25% complex aromatic structure resists biochemical conversion Hemicellulose 23% - 32% carbohydrate polymer C 5 and C 6 sugars (xylose-based) Cellulose 38% - 50% glucose polymer (C 6 ) H 3 C H H CH 3 H H H CH 3 H CH 3 CH CH 3 3 H 3 C H H H H H H H H H H H H H H H CH 3 H H H H H H H H H H H CH 3 CH 3 H H H H H 3 C H H H H H CH CH 3 3 H H H H H H H H H H H H H H H H H H H H H 3 C H H H H H H H H H H CH 3 H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H Innovation for ur Energy Future

18 Synthesis of larger Carbon Units ongoing R&D H CH CH 3 CH HC-CH H CH CH H Can these small oxygenates be polymerized to form larger molecules (C 9 C 20 units)? Innovation for ur Energy Future

19 Catalytic Pyrolysis vapors catalyst system modified vapors improved bio-oil Catalytic Pyrolysis R&D needs eliminate coking mechanisms of thermochemistry multifunctional catalysts Liquid Fuels Diesel Biomass Jet fuel Gasoline Diesel Innovation for ur Energy Future

20 Acknowledgment Co-workers: Dr. Stefan Czernik (mentorship) Stuart K. Black Michele Myers US Dept. of Energy ffice of Biomass Program Innovation for ur Energy Future

21 Innovation for ur Energy Future