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Aiming at improving the quality of syngas, the thermochemical behavior of syngas formation during a single coal particle gasification process is investigated based on a validated numerical model. Initially, simulations of coal gasification with steam (H2O) are conducted in a reactor, and the results show that the steam gasification generally favors the production of H2and CH4. However, the switch of agent to CO2into the gasifier influences the gasification products having H2, CO, and CH4. This then prompts the investigation of a mixture of H2O and CO2agent in the reactor’s environment, and the results show a promising indicator in producing an overall better syngas quality. Moreover, the influence of the coal particle size and gasification temperature on the syngas production is studied. The results identify that the concentration of syngas products is higher when using smaller coal particles as the behavior of heterogeneous reactions of CO formation is affected by the particle size. Finally, high temperature promotes the chemical reactions of the gasification process, resulting in the improved production of syngas.

Chemical kinetics for char originating from biomass devolatization are the essential requirements for studying the thermochemical processes of gasification. While the char kinetics for typical biomass and coal feedstocks are widely available in the literature, the gasification kinetics of char produced from food waste (FW) in CO2environment are still unknown. Further, the chemical compositions of char and FW are significantly different than those from woody biomass and coal. To address this, an in-depth kinetic study for the CO2gasification of FW char is presented in this paper. FW is initially pyrolyzed at 800 °C, and the char sample is sieved in the range of 53–100 μm before being gasified in a thermogravimetric analyzer (TGA) under CO2atmosphere at 850, 900, and 950 °C. The experimental results show that the char conversion rate increases with the reaction times and temperature. Using the TGA data, three different kinetic models, namely, volumetric model (VM), shrinking core model (SCM), and random pore model (RPM), are developed, and their effectiveness is thoroughly investigated. In comparison with the experimental results, SCM shows a high regression at 850 °C, while RPM shows a high regression at 900 and 950 °C. A power law (PL) model is also introduced, and it demonstrates that its regression is higher than 99% at every gasification temperature investigated. Therefore, the PL model most precisely predicts the gasification kinetics, which also agrees well with the RPM.