Experimental and kinetic studies on co-gasification of petroleum coke and biomass char blends

Abstract

The non-isothermal thermogravimetric method was applied to petroleum coke (PC), corncob char (CC) and their blends with the different mass ratios under CO2 atmosphere. The results show that CC with highly developed pore structure, high content of alkali metals and low degree of order had more reactivity than that of PC. The gasification reactivity of PC could be effectively improved by blending with CC. Meanwhile, there was obviously synergetic effect for the co-gasification of PC and CC. With the increase of mass ratio of CC, the synergetic effect first increased and then decreased. The synergetic effect was most obvious when CC mass ratio was 20%. Three nth-order representative gas-solid models: volume reaction model (VM), random pore model (RPM) and unreaction core model (URCM) were used to interpret the carbon conversion data. The overall fitting result of the RPM was slightly better than that of the VM and URCM. Furthermore, the synergetic effect between PC and CC was observed from the kinetics data calculated by RPM. The activation energy determined for PC and CC gasification was 203.2 kJ/mol and 243.3 kJ/mol, respectively, whereas, the lowest activation energy for their blends was 197.8 kJ/mol when CC ratio was 20%.