Fast pyrolysis based biorefineries Tony Bridgwater Bio-Energy Research Group Aston University, Birmingham, UK ACS, Washington DC, 31 August 2005 1
Chemicals in bio-oil The chemicals in bio-oil are derived from random thermal decomposition of hemicellulose, cellulose and lignin. Numbers of chemicals by group regularly identified in the literature: Acids 12 Sugars 8 Aldehydes 5 Esters 1 Alcohols 4 Ketones 32 Phenolics 56 Oxygenates 16 Hydrocarbons 6 Steroids 15 162
Yields of chemicals - 1 Chemicals ranked by maximum reported yield, wt% 30.4 levoglucosan 2.4 formaldehyde 15.4 hydroxyacetaldehyde 2.1 phenol 10.1 acetic acid 2.0 propionic acid 9.1 formic acid 2.0 acetone 8.5 acetaldehyde 1.9 methylcyclopentene-ol-one 5.2 furfuryl alcohol 1.9 methyl formate 5.0 catechol 1.9 hydroquinone 4.0 methyl glyoxal 1.7 acetol 3.6 ethanol 1.6 angelica lactone 3.2 cellobiosan 1.5 syringaldehyde 3.1 1,6-anhydroglucofuranose 1.4 methanol 2.9 fructose 1.3 1-hydroxy-2-butanone 2.8 glyoxal 1.3 3-ethylphenol
Chemicals values Quantity, t/y 10 7 10 6 10 5 10 4 10 3 10 2 10 1 10 0 10 0 10 1 10 2 10 3 10 4 10 5 10 6 10 7 Value, $/t
Applications examples Whole oil o Fuel (commercial) o Transport fuel o Hydrogen o Slow release fertiliser o Emission control o De-icer o Preservative o Resin precursors Fractionated oil o Liquid smoke (commercial) o De-icers o Resin precursors o Hydrogen o Fuel additives Specific chemicals o Acetic acid (commercial) o Hydroxyacetaldehyde o Levoglucosan o Levoglucosenone o Maltol
BIOMASS Process modification PRETREAT Remove ash Remove HC / C Add catalysts PYROLYSE Vary parameters Thermal cracking Catalytic cracking BIO-OIL CONDENSE LIQUID Upgrade physically Differential condensation Filter liquid Add solvents Upgrade catalytically De-oxygenate Reform Upgrade chemically Gasify to syngas
Biorefinery While biorefineries are not new, the recognition of their strategic and economic potential is recent. A biorefinery needs to optimise the pyrolysis and applications system in terms of: o Costs and economics, including markets, o Yield or technical performance, o Environment and impact, o Social aspects. As these are not necessarily compatible or consistent, optimisation usually requires their careful consideration and balance. Economics will usually dominate where commercial considerations are involved.
Biorefinery concepts Integrate production of higher value chemicals and commodities, as well as fuels and energy, Optimise use of resources, maximise profitability, maximise benefits, minimise wastes Biomass Fast pyrolysis (Primary processing) Secondary processing Tertiary processing Chemicals Commodities Fuels Byproducts and wastes
Biorefinery examples NREL Separate phenolics for resins leaving an aqueous fraction Reform aqueous fraction for hydrogen as product or for hydrogenation Red Arrow Separate liquid smoke and other specialities Burn organic residue as fuel
Levoglucosan example Process Yield LG on dry wood Residues (disposal or re-use?) Feed cost, $/dry t Capital cost, indexed LG cost, $/kg Pyrolyse wood, separate & purify levoglucosan 1.6% 98.4% 40 100 82.5 Acid wash wood, dry, pyrolyse, separate & purify levoglucosan 7.3% 92.7% 40 228 18.9 Purchase cellulose, pyrolyse, separate & purify levoglucosan 25% 75% 400 57 10.6
Other potential products Furfural from xylose for: o tetrahydrofuran and butanediol for engineering elastomers 5-hydroxymethylfurfural from glucose for: o furan-di-carboxylic acid for engineering polymers o levulinic acid for: Levulinic acid based esters as green solvents & fuel additives Levulinic acid based lactones for polymers and nylons Phenol from lignin for: o phenol esters and ethers for surfactants and performance fluids o substituted phenols as antioxidants and fire retardant agents for plastics
Potential polymers Thermoplastic Polymers Tetrahydrofuran based high performance resins synthesis and processing Polylacton based segmented block copolymer resins synthesis and processing Furan-di-carboxylic acid based thermoplastic co-polyesters and co-polyamides Thermoset Polymers Phenolic resins and epoxy resins synthesis and processing
Definition of biorefinery The optimised performance of the use of biomass for materials, chemicals and energy applications. Performance relates to the following measures: o Cost and economics o Yield o Environment, Impact and Carbon balance o Social aspects These are not necessarily compatible or consistent in defining the best process system, so optimisation usually requires their careful consideration.