The gasification experiments of swelling coal using N-methyl pyrrolidone(NMP) as the solvent were carried out on a thermo-gravimetric analyzer. The influence of swelling paramters such as time

temperature and ultrasonic irradiation on gasification characteristics of lignite was investigated

and the gasification characteristics of different types of coal pretreated by swelling was also analyzed. Moreover

the relative apparent kineticsparameters were calculated by Coats-redfern method with the first order reaction. The results show that

the total conversion ratio of the swelling coal was improved

the gasification of all the coals but lean coal showed two-stage reactivity

it turned into three-stage reactivity after swelling pretreatment

indicating the swelling pretreatment helped shorterning the reaction time. Higher swelling temperature and longer ultrasonic irradiation time reduced mass loss of the lignite during gasification

and the swelling time had little effect on final weight loss rate and reaction rate of the lignite. After swelling

the increase of lignite's weight loss rate was the largest

while that of the bituminous coal was the smallest.