Experimental investigation of rice straw oxidative pyrolysis process in a hot-rod reactor

Abstract

In order to improve the utilization of rice straw resources, oxidative pyrolysis of rice straw was investigated in this work. The effects of temperature and oxygen concentration on rice straw oxidative pyrolysis were taken into consideration. Results show that more permanent gases and water were produced under oxidative atmospheres, while the yield of char and tar decreased. The main gaseous products were CO and CO2 due to the heterogenous oxidation of rice straw/char or secondary reaction of nascent volatiles. Gas chromatograph coupled with a mass spectrometer (GC/MS) results show that the oxidative pyrolysis promoted the conversion of primary tar to generate secondary and tertiary tar via in-situ exothermic reaction and active radical attack. Pore structure analysis results of bio-char samples show that oxidative treatment benefited the formation of micro pores and inhibited bio-char thermal annealing at high temperature. In general, the oxidative treatment promoted the pyrolysis process and benefited the char modification via in-situ oxidation and formation surface active structure and porosity.