Gravity separation and its effect on CO2

The CO2–blown integrated coal gasification combined cycle (IGCC) is a promising electric power generation technology that will reduce CO2 emissions due to its high efficiency. Recent studies have found that base metals improve coal char gasification in cases when they interact with the char matrix at an atomic level. This paper clarifies the effect of heavy medium separation, a popular coal cleaning technology, on CO2 char gasification. Datong Coal from China was ground to below 20 mesh for the cleaning process, followed by a sink and float test and thermo-gravimetric analysis. The tests revealed that the highest separation efficiency occurred at a specific gravity of 1.45, resulting in a dramatic reduction of ash content from 10.2% to approximately 4%, while about 85% of combustibles were recovered. Chars from different specific gravity fractions exhibited varying gasification reactivities, with heavier fraction char showing higher reactivity compared to lighter fractions. This trend correlated with ash content, as the heavier fractions had more ash. The removal of ash from well-ordered holes in Fusinite and Semi-fusinite could enhance gasification reactivity.