Experimental research on low temperature pyrolysis of biomass extrusion bar of rice husk and sawdust

The characteristics of biomass low temperature pyrolysis(below 280℃) was analyzed using wood block, sawdust and rice husk extrusion bar as biomass material in this paper. The effects of heating temperature and time on solid-state product calorific value, weight conversion rate and energy conversion rate were studied. The optimization low temperature pyrolysis parameters for sawdust extrusion bar are obtained, which are pyrolysis temperature 260～270℃, and pyrolysis period 4 h, its weight conversion rate under the optimization parameter is 64.8%～69.9%, energy conversion rate is 76.9%～80.7%, and calorific value rate is 21.68～22.12 MJ/kg; the optimization low temperature pyrolysis parameters for rice husk extrusion bar are pyrolysis temperature 270℃, and pyrolysis period 4 h,its weight conversion rate, energy conversion rate and calorific value are 63.2%, 79.1% and 21.33 MJ/kg, respectively under the optimization parameters. The combustibility test show that the fume lasting period is reduced distinctively for pyrolysis sawdust and rice husk extrusion bar, compared with non pyrolysis one, which mean that its combustibility characteristic is improved greatly. The low temperature pyrolysis sawdust and rice husk extrusion bar was also convenient in storage and transportation, therefore could be a substitution for wood and coal as energy used in production and household. Furthermore, the distillation production during low temperature pyrolysis is less, which could reduce the investment on distillation collection and purification.