Methanation of CO over coal char loaded with K₂CO₃

The catalytic performance of coal char loaded with potassium carbonate on the CO methanation reaction was investigated in a pressurized fixed bed reactor. The results show that the catalytic activities of raw coal pyrolysis char and demineralized coal pyrolysis char are very low, while with loading 10% potassium carbonate, the catalytic activity of chars increases obviously and the yield of methane reaches to 30%. The gasification rate changes with the progress of carbon conversion and has a maximum value at a carbon conversion around 22%. The analysis by FT-IR indicates that the interaction of potassium carbonate with coal can form C-O-K complexes during pyrolysis at 700℃, with an infrared band around 1 100 cm^-1. The intensity of this band is found to be proportional to the steam gasification rate of the carbon. After reaction in CO-H₂ mixture gas at 700℃ for 180 min, the intensity of C-O-K vibration increases more or less.