Investigation of K₂CO₃‐Catalyzed Pyrolysis and Steam Gasification of Coal Char

Pyrolysis and steam gasification experiments of coal char with and without K 2 CO 3 were performed using a thermogravimetric analyzer to investigate the effect of catalyst loading method on gasification reactivity at different temperatures (650–800 °C), and an additional redox cycle experiment of catalyzed char‐steam gasification was conducted in a fixed‐bed reactor. The results showed that, at low temperature, the solution impregnation method had a larger effect on the gasification reactivity than the physical blending method; at temperatures above 700 °C, the differences of two methods diminished due to the high mobility of potassium. In catalytic pyrolysis, the release of CO and CO 2 indicated that K 2 CO 3 reacted with carbon. The redox cycle experiments suggest that the potassium reacted with carbon to produce intermediates of the form K 2 O 2 C, K 2 OC, and K 2 C. The K 2 C intermediate may help to explain the release of more H 2 during the initial period of catalytic coal char–steam gasification.