Parametric study of pyrolysis and steam gasification of rice straw in presence of K2CO3

Abstract

A parametric study of pyrolysis and steam gasification of rice straw (RS) was performed to investigate the effect of the presence of K2CO3 on the behavior of gas evolution, gas component distribution, pyrolysis/gasification reactivity, the quality and volume of synthetic gas. During pyrolysis, with the increase in K2CO3 content in RS (i) the instantaneous CO2 concentration was increased while CO concentration was relatively stable; (ii) the yield of CO2 and H2 increased on the cost of CH4. During steam gasification of RS, with the increase in K2CO3 content in RS (i) the instantaneous concentration of CO2 and H2 increased while instantaneous concentration of CO and CH4 decreased; (ii) the yield of CO2 and H2 production and total yield increased; and (iii) yield of CO and CH4 production followed the order: 9% K2CO3 RS<6% K2CO3 RS<raw RS<3% K2CO3 RS<water-leached RS. Water-leached RS showed the highest pyrolysis reactivity, while stream gasification reactivity was proportional to K2CO3 content in RS. The results of this study reveal that the presence of K2CO3 during pyrolysis and steam gasification of RS effectively improves production of H2 rich gas.