Effect of Temperature and Catalyst on Biofuel Yields from Pyrolysis of African Copaiba Balsam (Daniellia Oliveri) Sawdust

Abstract

The effect of sodium carbonate (Na2CO3) on biofuel yields from pyrolysis of Daniellia oliveri sawdust in a fixed bed reactor has been studied. The sawdust was procured from the New Sawmill, along Ilorin-Ibadan expressway, Ogbomoso, South-Western Nigeria. The sample was sundried for three days to reduce its moisture content. Catalytic pyrolysis of the sawdust was performed with different weight percentages of catalyst (10, 20, 30 and 40 wt.%) in the feed. Noncatalytic pyrolysis was also performed for the same temperatures and biofuel yields from both sets of experiments were compared. Char yield increased with an increasing percentage of catalyst and were higher than those from non-catalytic pyrolysis in all but one case, the highest being 49.42% at 500 oC (biomass/catalyst ratio of 60/40) and the lowest, 15.41% at a non-catalytic temperature of 400 oC. Bio-oil yields at 400 and 600 oC followed the same trend up to biomass/catalyst ratio of 70/30 while the yields at 500 oC, though higher than those from noncatalytic experiments in most cases, did not significantly change with an increasing percentage of catalyst. The highest yield of bio-oil (37.64%) was obtained at 600 oC (biomass/catalyst ratio of 90/10) and the lowest (16.41%) at 400 oC (biomass/catalyst ratio of 80/20). Gas yields in most cases decreased with an increasing percentage of catalyst and were all lower than those from non-catalytic experiments, the highest yield (62.77%) obtained at a temperature of 400 oC (noncatalytic) and the lowest (19.73%) at 500 oC (biomass/catalyst ratio of 60/40).