Shumin Fan

Comparison of catalytic pyrolysis and gasification of Indonesian low rank coals using lab-scale bubble fluidized-bed reactor

Various methods are used in the coal gasification technology for increasing the efficiency of low rank coal to the level of high rank coal through catalytic gasification. The catalyst used in the catalytic gasification process lowers the activation energy required in the coal gasification reaction. Our purpose was to determine the characteristics of the reaction conditions for producing syngas and the characteristics for comparison catalytic pyrolysis and gasification performance. Among various coals, we used Indonesian low rank coals (Indonesian lignite, MSJ, and Roto South) characterized by a large deposit volume and low cost. Catalytic pyrolysis and gasification experiments were run under the same experimental conditions (reactor type, reaction temperature, catalyst content, and catalyst input method), and the characteristics were compared. Taking the conversion and heating values into consideration, the optimal conditions for catalytic gasification in this study were an H2O/C mole ratio of 10, temperature of 800 °C, and 10 wt% catalyst impregnation.

Coal structure change by ionic liquid pretreatment for enhancement of fixed-bed gasification with steam and CO2

An innovative pretreatment of Indonesian low-rank coal (ILRC) by 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) ionic liquid (IL) was conducted. The obtained IL pretreated coal had a loose and porous structure. Fourier transform infrared spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET) analysis showed that pretreated ILRC had a stronger absorption ability and an increased average pore size (from 23.6 to 51.8 nm). Steam-coal gasification was conducted to explore the effect of coal pretreatment. The result showed that 1.63-times more hydrogen was generated from pretreated coal compared to original (i.e., untreated) coal, and carbon conversion (Xc) increased from 89.03 to 97.25%. During CO2 coal gasification, IL pretreated coal had a greater CO2 consumption potential and generated more CO. The chemical exergy of syngas of the pretreated coal gasification was higher than that of the untreated coal gasification with CO2 at 900 °C. In addition, pretreated coal emitted less CO2 than untreated coal at 900 °C.