Gasification Reactivities and Pore Structure Characteristics of Feed Coal and Residues in an Industrial Gasification Plant

Gasification reactivities and pore structure characteristics of raw coal, coarse slag, filter cake, and demister slag in industrial gasification plant were investigated and compared with each other in this study. Results show that the reactivity of raw coal gasification is the highest because of the biggest specific surface area, the most developed pore structure, the most micropores and combustible matter contents of raw coal. The reactivities of filter cake and demister slag are lower than those of raw coal because these two samples have experienced a similar high temperature gasification process. After that process, the amount of micropores decreased and many pore structures were blocked by molten materials. Coarse slag has experienced the longest gasification process, the combustible matter contents are fewest, the specific surface area is the smallest, and the micropore size distribution is the narrowest. Therefore, the gasification reactivity of coarse slag is the lowest. Moreover, gasification of the mixture of raw coal and gasification residues under a temperature higher than ash fusion temperature can improve the utilization of residues because neither the main pore structures of raw coal nor the process of gasification can be affected by adding the gasification residues to raw coal.