Direct conversion of an agricultural solid waste to hydrocarbon gases via the pyrolysis technique

Abstract

The increased awareness toward the global warming and the environmental pollution problems has stimulated the utilization of the alternative energy sources since they can positively take part in minimizing such problems. Among these sources, biomass based solid wastes is counted as one of the most promising in the field of energy production. Thus, the current research work focuses on the conversion of rice straw (a biomass-based solid waste) into hydrocarbon gases in general and methane (main constituent of natural gas) in particular. The reduction of the operational temperature and the elevated rate of solid-to-gas conversion are newly presented approaches in this research. Specifically, the used operating temperature, in this study, had been 250 °C while the well-known temperature range for slow pyrolysis is 380–550 °C. Another approach is represented in this work via the orientation of the obtained biogas to become mainly hydrocarbon gases instead of CO, CO2 and CH4 mixture, as the common for such pyrolysis processes. The attained high rate of solid-to-gas conversion (80%) while at low temperature is also a new approach of this study since such high rate is just possible in the flash pyrolysis (750–900 °C). The increased conversion rate was achieved via reducing the particles size of the used solid-biomass to a nano-sized range.