Pressurized catalytic gasification of high ash fusion temperature coal: catalytic activity of K2CO3 and potassium recovery

In this study, catalytic steam gasification of high ash fusion temperature coal using K2CO3 as catalyst was carried out in a pressurized fixed bed. The potassium catalyst recovery was also conducted via wash and digestion by Ca (OH)2. It turned out that increasing temperature and K2CO3 loading enhanced the carbon conversion and CH4 yield. At 800℃ and loading of 15% K2CO3, the carbon conversion reached 96.1% and CH4 yield was 0.24 m3·(kg C)-1. The potassium recovery increased to a peak as the carbon conversion rose and then declined, which was more relevant to existing forms of potassium with carbon and ash. By optimizing the conditions of wash and digestion, the potassium recovery in ash with high carbon conversion reached 96.5%. © All Right Reserved.