Co-gasification reactivity and kinetics of municipality and coffee waste residue hydrochar and South African density separated coal blends

Abstract Residues obtained from hydrothermal liquefaction of municipality waste (MSWR) and coffee waste (CR) were blended with coal and charred at 1000 °C. Co-gasification experiments were conducted on the coal, MSWR, CR, and their respective blended chars using a thermogravimetric analyser. The reactivities of the char samples decreased in the order: MSWR > CR > MSWR-coal blend > CR-coal blend > coal. RPM was found to best predict the reaction profile of the coal, and the blended chars, except for the MSWR and CR chars, which fitted satisfactorily upon the application of the MRPM. The activation energies obtained using the RPM, MRPM, and the different reactivity models showed that the MSWR, CR, and the blend chars have lower activation energies when compared to the feed coal char. Although the MSWR and CR exhibited catalytic influence on the coal char during co-gasification, the synergistic effect was inhibitory with all determined SE