Investigation on the existing form of organonitrogen and organosulfur compounds in Illinois No.6 coal

Nitrogen and sulfur in coal are one of the main sources of environment pollution. Much attention has been paid on the existing form of nitrogen and sulfur in coal. The solvent-insoluble portion, namely residue, of the argonne premium coal Illinois No. 6 was subjected to mild hydrotreatment. The products derived from hydrotreatment were extracted with different solvents, and the extracts were analyzed by a gas chromatography-mass spectrometer. The results show that the total extract yield is 4.1% for the products from noncatalytic hydrotreatment, while that from Ni-catalyzed hydrotreatment can reach 13.5%. A total of twenty-seven organonitrogen and organosulfur compounds(ONCs and OSCs) are detected in the products from Ni-catalyzed hydrotreatment, and are much more than those from noncatalytic one(ten). The identified ONCs and OSCs mainly include isocyanatobenzene, isothiocyanatobenzene, anilines, quinoline, dimethylsulfoxide, thiols, benzenethiols, sulfides, thiophenes, and thianthrene, which indicate that the strategy combing mild hydrotreatment and fractional extraction is efficient for disclosing the existing form of ONCs and OSCs in coal at the molecular level.