Influences of biomass leachate (BL) additives (rice straw leachate(RSL) and corn straw leachate(CSL)) on reactivity characteristics and structural evolution of petroleum coke (PC)-CO2 gasification were investigated. Specific reactivity (SR0.9) was proposed to quantify influence of BL on PC char gasification and the results demonstrate that BL facilitated PC char gasification and RSL showed more obvious catalytic effect, which was mainly attributed to positive effect of BL on carbon structure evolution and AAEM specie retention during PC char gasification. The results from Raman band area ratio difference and AAEM/Si difference of gasification semi-chars demonstrate that BL was conducive to reducing order degree of carbon structure, increasing amorphous carbon structure and enhancing AAEM concentrations during PC char gasification and RSL exhibited more positive effect. Furthermore, SR0.9 variations with temperature show that catalytic effects of BL initially weakened and then enhanced as gasification temperature increased from 1000 to 1300 degrees C, which was well related with variation trend of positive effect of BL on char structural evolution at different temperatures. Free-model method exactly predicted char gasification with high correlation coefficients (>0.98), and activation energy of PC char with CSL and RSL additions were 28.00 kJ mol(-1 )and 41.68 kJ mol(-1) lower than that of PC char, respectively. (C) 2020 Elsevier Ltd. All rights reserved.