Abstract
Oxidative reforming of coal liquefaction residues was performed for two samples (Illinois No.6 and Yallourn coal liquefaction residues) at 150-290°C to change some physical constants to adequate values for the gasification in a coal gasification reactor. These physical constants (softening point and fluidity) and reactivities (pyrolysis and reaction with CO2) were also investigated. As the oxidation proceeded, softening points increased gradually and fluidities decreased for both samples. Adhesion forces decreased with oxidation and reached the value of original coal at 290°C for 0.5h for both samples. Pyrolysis reactivity was decreased by oxidation. Reactivity with CO2 increased for the Illinois No.6 liquefaction residue and decreased for the Yallourn liquefaction residue. To obtain information on structural changes during oxidation and their relation to properties and reactivities, FT-IR spectra of the samples were taken. Aliphatic and aromatic structures in the Illinois No.6 liquefaction residue decomposed and some carbonylic and hydroxylic functionalities were formed. Aliphatic structures in the Yallourn liquefaction residue decomposed and some carbonylic, ester and ethereal crosslinks were formed. Properties and pyrolysis reactivities were changed by formation of oxygen-containing functional groups. The difference of reactivity with CO2 in the two samples was due to the difference in structural change caused by oxidation.
