Impact of K2CO3 catalyst loading on the CO2-gasification of Genesse raw coal and low-ash product

•CO2 gasification behavior of Genesse coal and low-ash product are similar.•Addition of K2CO3 increases rate for low-ash product more than parent coal.•Optimal K2CO3 loading of 10 wt%.•Activation energy changes with K2CO3 loading and conversion.•Rate data fit well by extended random pore model.

In this study, the effects of K2CO3 addition to Genesse sub-bituminous coal, before and after ash reduction, on conversion and gasification rate were investigated for CO2 gasification at 700–800 °C. For the uncatalyzed samples, no significant changes in gasification rate and char conversion were observed for the low-ash product (12 wt% ash) compared to the raw coal (33 wt% ash). However, with the addition of 10 wt% potassium catalyst, the low-ash product exhibited a higher gasification rate than the raw coal. An increase of the catalyst loading up to 50 wt% resulted in a decline of the gasification rate for both coal samples. The activation energy increased with conversion and at higher K2CO3 loadings. Kinetic modeling showed that the extended-random pore model fits the experimental data well for both coal samples and supported the speculation that excess catalyst blocks pores, resulting a reduction in gasification rate.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide