In this study, the thermodynamics of a novel strategy, i.e., biomass/CO2 gasification integrated with heat recovery from hot slags in the steel industry, were systemically investigated. Both the target syngas yield and the polluting gas release were considered where the effect of gasifying conditions including temperature, pressure and CO2 reacted was analyzed and then the roles of hot slags were further clarified. The results indicated that there existed an optimum temperature for the maximization of H-2 production. Compared to blast furnace slags, steel slags remarkably increased the CO yield at 600-1400 degrees C due to the existence of iron oxides and decreased the S-containing gas releases at 400-700 degrees C, indicating potential desulfurizing ability. The identification of biomass/CO2 gasification thermodynamics in presence of slags could thus provide important clues not only for the deep understanding of biomass gasification but also for the industrial application of this emerging strategy from the viewpoint of syngas optimization and pollution control. (C) 2016 Elsevier Ltd. All rights reserved.