High-temperature char gasification of anthracite/petroleum coke: using biomass leachate as cheap-effective additive

摘要

Rice straw leachate (RSL) was employed as cheap-effective biomass-based additive for anthracite/petroleum coke (JM/PC) gasification. The influence of RSL on high-temperature (1,000-1,300 degrees C) char gasification reactivity and kinetics was analyzed by thermogravimetric analysis. The results demonstrate that for PC char, catalytic effect of RSL on its gasification reactivity existed within the whole temperature range and was initially weakened and then enhanced as gasification temperature increased (turning-point temperature, 1,200 degrees C). For JM char, as gasification temperature increased, the influencing form of RSL on its gasification reactivity was initially presented as the weakened catalytic effect and turned into the reduced inhibition effect within 1,200-1,300 degrees C. These phenomena were mainly attributed to the concentration and activity variations of alkali/alkaline earth metal species derived from RSL during JM/PC char gasification at different temperatures. Kinetics analysis based on conventional models indicates that random pore model (RPM) was more suitable to describe char gasification. Moreover, RSL additive could reduce the activation energy of JM char and PC char gasification by 12.71 and 43.39 kJ center dot mol(-1), respectively, which implied that RSL help to improve char gasification kinetics and exhibited more positive effect on PC char. Kinetics analysis based on free-model method verified the reliability and accuracy of RPM.