The synergistic effecting mechanisms of biomass pyrolysis, biomass char gasification, and biomass ash on CO2 co-gasification of biomass and high-sulfur petroleum coke

•Antagonistic and synergistic interactions exhibited during co-conversion.•Adding B, CB and AB significantly increased the gasification reactivity of PC.•The mechanism of metal in AB improves the reactivity of PC was different.•Organic matter promoted the catalytic capacity of inorganic components.•The catalytic capacity was negatively correlated with the total ionic potential. To investigate the synergistic effecting mechanisms of biomass pyrolysis, biomass char gasification, and biomass ash during the co-gasification of biomass and high-sulfur petroleum coke (PC), various biomass waste (B), biomass char (CB) and low-temperature ash of biomass (AB) were blended with PC. Gasification reaction characteristics of B, PC, and their respective mixtures were assessed using a thermogravimetric analyzer. Their gasification reactivity, synergistic effects, and kinetic parameters were comprehensively compared. The total ionic potential (TMP) was defined to quantify the catalytic capacity. The results indicated that the incorporation of B, CB, and AB significantly boosted the gasification reactivity of PC，and the pyrolysis stage (SP) and the gasification stage (SG) of PC:B exhibited antagonistic and synergistic interactions, respectively. The first-order chemical reaction (Q1) proved more suitable for SP, whereas the core-shrinkage model (R2) was more applicable for SG. The mechanisms of B, CB, and AB improving the gasification reactivity of PC were different (B and CB: by lowering active energy). The catalytic capacity was negatively correlated with the TMP. The mechanism of AB catalyzed PC-CO2 gasification varied with the mineral composition. The participation of organic matter in B and CB would promote the formation of Lewis Base Center metal–organic frameworks, thereby improving the catalytic capacity of inorganic components by increasing the pre-exponential factor and the reaction rate constant.