Catalytic flash pyrolysis of oil-impregnated-wood and jatropha cake using sodium based catalysts

• Sodium based catalysts are very effective for de-oxygenation of bio-oil.
• Higher heating value of catalytic bio-oil was upto 41.8 MJ/Kg.
• Catalytic pyrolysis produced hydrocarbons rich bio-oil.
• Acids were completely removed leading to a pH neutral bio-oil.
• Phase separation of pyrolysis liquid yielded an almost water free bio-oil (1 wt.% water content).

Catalytic pyrolysis of wood with impregnated vegetable oil was investigated and compared with catalytic pyrolysis of jatropha cake making use of sodium based catalysts to produce a high quality bio-oil. The catalytic pyrolysis was carried out in two modes: in-situ catalytic pyrolysis and post treatment of the pyrolysis vapors. The in-situ catalytic pyrolysis was carried out in an entrained flow reactor system using a premixed feedstock of Na2CO3 and biomass and post treatment of biomass pyrolysis vapor was conducted in a downstream fixed bed reactor of Na2CO3/γ-Al2O3. Results have shown that both Na2CO3 and Na2CO3/γ-Al2O3 can be used for the production of a high quality bio-oil from catalytic pyrolysis of oil-impregnated-wood and jatropha cake. The catalytic bio-oil had very low oxygen content, water content as low as 1 wt.%, a neutral pH, and a high calorific value upto 41.8 MJ/kg. The bio-oil consisted of high value chemical compounds mainly hydrocarbons and undesired compounds in the bio-oil were either completely removed or considerably reduced. Increasing the triglycerides content (vegetable oil) in the wood enhanced the formation of hydrocarbons in the bio-oil. Post treatment of the pyrolysis vapor over a fixed bed of Na2CO3/γ-Al2O3 produced superior quality bio-oil compared to in-situ catalytic pyrolysis with Na2CO3. This high quality bio-oil may be used as a precursor in a fractionating process for the production of alternative fuels.