Catalytic effects of ion-exchangeable potassium ion on combustion behavior of Loy Yang lignite

K+ was loaded onto the acid-treated Loy Yang (LY) lignite. The effects of K+ on combustion behavior of LY lignite were investigated using thermogravimetric analysis. The Fourier transform infrared spectroscopy and Xray diffraction results showed that K+ was successfully loaded on the lignite, and it was in the form of amorphous state. Ignition temperature (T-i) values for the K+-loaded samples were higher than that for the acid-treated sample, and T-i increased with increasing K+ content. The opposite relationship was observed for peak temperature (T-p). Based on the changes in T-i, T-p, maximum combustion rate, and activation energy calculated using the Kissinger-Akahira-Sunose and Ozawa-Flynn-Wall methods, a mechanism was proposed for the catalytic combustion. K+ could enhance the release of volatiles. Moreover, K+ acted as a carrier of oxygen and promoted the oxygen transfer to char, resulting in the increase in CO2 yield.