Exploration of Lignocellulosic Biomass Precision Pyrolysis for Advanced Biofuel Production

Abstract. Catalytic fast pyrolysis (CFP) is proven one of the most promising processes for effectively converting biomass to liquid advanced biofuels. The yield and quality of biofuels are depended on biomass species, reactor type, operating conditions (such as temperature, pressure, heating rate, etc.) as well as the presenting of appropriate catalysts. Based on current CFP research, a hypothesis of biomass precision pyrolysis was proposed. A novel accurate control catalyst fast pyrolysis (ACCFP) reactor was invented and tested for exploration of biomass precision pyrolysis possibility. Various lignocellulosic biomass materials such as switchgrass, corn stover, prairie cordgrass, and pine sawdust were tested. The effects of reaction temperature, pressure, and heating rate on pyrolysis products (bio-oil, bio-char, and biosyngas) were investigated. ZSM-5 combined with various metal catalysts were applied in the ACCFP process. The pyrolysis products (bio-oil, bio-char, and biosyngas) produced were characterized for their physicochemical properties such as total acid number (TAN), water content, density, pH value, viscosity, higher heating value, and/or chemical composition. The results indicated that it is possible to accurately control CFP processing conditions to produce target bioproducts, which may lead to biomass precision pyrolysis. Compared to conventional pyrolysis, the ACCFP process could improve pyrolysis products yields and quality, such as greatly reducing oxygen content in the bio-oils produced. Although further research is needed, the study confirms that precision biomass pyrolysis may be an effective pathway for converting lignocellulosic biomass to advanced biofuels or chemicals.