Abstract Biomass torrefaction, co-gasification of coal with raw and torrefied biomass, and an approach to co-processing the torrefaction condensates with coal and coal char were investigated in this study. Torrefaction pretreatment produced not only high-quality solid fuels but also waste condensates. Co-gasification of coal/torrefied biomass blends exhibited stronger synergy compared to the lower synergy degree of the coal/raw biomass blends. Furthermore, we proposed a rational approach to blending the torrefaction condensates with coal or coal char, by which a binary-mixed solid fuel with biomass constituents to coal or coal char mass ratio of 12–18:100 could be obtained. In this way, the condensates can be co-converted in a coal-based gasification or combustion systems. The most attractive technical benefit of this approach is that the blending of the condensates with coal or coal char significantly enhanced the gasification reactivity of the blends.