Addition of torrefied algal biomass to improve land-based biomass gasification for hydrogen-rich gas production

Abstract

Steam co-gasification of two kinds of biomass with different activities could generate synergetic effect on the fuel gas production. In this study, steam co-gasification of torrefied biochar from seaweed with land-based biomass, i.e., cedar wood and rice husk, was performed for the production of hydrogen(H2)-rich fuel gas, in which seaweed was torrefied at different temperatures (i.e., 200, 250 and 300 °C), and the performance of co-gasification was evaluated at three different gasification temperatures (i.e., 650, 700 and 750 °C) under atmospheric condition with three different steam flow rates (i.e., 0.05, 0.10 and 0.15 g/min) in a fixed bed reactor with a feed biomass and torrefied biochar weight ratio of 1:1. Taguchi's orthogonal array of L9 (34) was used to determine the importance of each parameter on the amount of H2 produced. It is found that the optimum parameters resulting in the highest H2 gas were the co-gasification cedarwood with the torrefied seaweed obtained at a torrefaction temperature of 300 °C at a co-gasification temperature of 750 °C with a steam flow rate of 0.10 g/min. Especially, at this condition, the produced H2 gas was nearly twice higher than that from cedarwood individual gasification and 11 % less tar produced than the calculated result.