Enhancing the Steam Gasification Reactivity of Coal by Boosting the Factors Affecting the Gasification Reactions in the Stepwise Coal Conversion

摘要

Factors affecting the steam gasification reactivity of coal have been reviewed. Studies have been performed on investigating the effects of organo-refining (solvent extraction) using coal-derived solvents, such as anthracene oil and liquid paraffin. The residual coals obtained from the organo-refining of coal were subjected to steam pyrolysis at 650℃ to generate active chars. The steam gasification reactivity of original coal, anthracene oil extracted residual coals, anthracene oil-liquid paraffin (successively) extracted residual coals, and their chars were studied first in a laboratory gasifier and then by using thermogravimetric analysis apparatus in steam atmosphere. Nonisothermal kinetic studies revealed that organo-refining and steam pyrolysis are beneficial pretreatments for the steam gasification of coals/chars. These pretreatments leave sufficient residual volatile matter in coals/chars, increase the active surface area, and expose and make available the finely dispersed mineral matter of coal (which acts as catalysts). These observations were also supported by the DTG studies. Present studies led to the development of a stepwise coal conversion process, a clean coal technology to generate H_2 or for use of the integrated gasification combined cycle power generation or of fuel cells.