(436d) The Influence of Non-Condesible Gas Recycling On the Yield of Fractional Catalytic Pyrolysis Products

The fractional catalytic pyrolysis of biomass generates a considerable amount of non-condensible gases stemming from the cracking of the primary biomass degradation products.  In some gases, the gas fraction can exceed 50 wt% of the biomass.  This gas can conceivably be either recycled to fluidize the reactor or combusted to fuel the pyrolysis reaction.  The important question to ask is whether the recycling of this gas influences the product yield and composition.  We investigated both the recycled non-condensible gases (NCG) , carbon monoxide, carbon dioxide and synthetic mixture of gases for their effect on the catalytic pyrolysis of hybrid poplar wood.   The NCG in all cases appeared to increase the yield of the liquid products and as well as increase the yield of the hydrogen fraction.  However, the viscosity of the oils appeared to have increased with the recycling of the gases.  Carbon dioxide alone also appeared to affect the viscosity of the liquid products and underwent the water gas shift reaction producing more hydrogen.  The carbon dioxide appeared to have very little effect on the pyrolysis process.  In general, the carbon dioxide appeared to be inert.  The hydrocarbons in the NCG also appeared to undergo some reactions and therefore increasing the yield of the products.  Thus, the recycling of the NCG in the fractional catalytic pyrolysis process has a beneficial effect on the entire process.