Research on the co-combustion characteristics and kinetics of agricultural waste hydrochar and anthracite

The study aims to discover the co-combustion reaction mechanism of agricultural waste hydrochar and anthracite and to clarify the main influencing factors of the co-combustion reaction of the mixture. At the same time, it also provides a theoretical basis for revealing the optimal ratio of biomass hydrochar in the mixture and the application of biomass hydrochar in steel plants. Biomass hydrochar and anthracite were systematically investigated by physicochemical property analysis and non-isothermal thermogravimetric analysis. The results show that biomass hydrochar has better combustion performance due to the lower graphitization order and larger specific surface area, while the combustion performance of anthracite is relatively poor. The addition of biomass hydrochar can improve the combustion performance of anthracite. There is an obvious synergy in the co-combustion process due to the differences in the volatile content and graphitization degree of different samples. Two kinetic equations, Kissinger–Akahira–Sunose (KAS) and Flynn–Wall–Ozawa (FWO), are used to perform kinetic fitting on the combustion reaction of the mixture, but the fitting effect of the FWO equation is better than that of the KAS equation. The FWO kinetic fitting results indicate the optimum addition amount of 60% hydrochar with the smallest activation energy (118.95 kJ/mol). The research on the co-combustion of biomass hydrochar and anthracite is vital, contributing to the formation of biomass resource industrial applications.