Effect of CaO-SiO2-FeO slag system on coal gasification reaction in CO2-Ar atmosphere and kinetic analysis

Abstract

A new method of coal gasification with steelmaking slag as heat carrier and catalyst is put forward. At the same time, from the carbon cycle perspective, CO2 is used as a gasification agent instead of water vapor. The effects of coal type, slag ratio, and experimental temperature on coal gasification reaction were discussed through constant temperature thermogravimetry, heating thermogravimetry experiments, and the kinetic analysis of thermogravimetry data carried out. The results show that steelmaking slag has a catalytic effect on coal gasification reaction, which is beneficial to coal gasification reaction, but the additional amount of slag has a suitable value. Because low-rank coal contains more oxygen-containing functional groups, the catalytic effect of slag on low-rank coal is stronger. The gasification reaction temperature should be controlled near the ash melting point temperature of coal. At the same time, the kinetic parameters of coal gasification reaction under different conditions were obtained, and the kinetic mechanism model was constructed. This study is of great significance to the recovery and utilization of waste heat of steelmaking slag and the emission reduction of greenhouse gases.