DETERMINATION OF NITROGEN AND OXYGEN FUNCTIONAL-GROUPS IN COAL-DERIVED ASPHALTENES

Coal-derived asphaltenes and their derivatives, isolated from five demonstration coal liquefaction processes (PAMCO SRC, Catalytic Inc. SRC, HRI H-Coal, Synthoil and FMC-COED) were analyzed for hydroxyl content by silylation followed by proton NMR analysis. Nonbasic pyrrolic nitrogen content was determined for these asphaltenes by elemental analysis after they were separated by solvent elution chromatography and treated further by methylation with methyl iodide to remove residual basic asphaltenes. Nonhydroxylic ether oxygen and basic pyridine-like nitrogen content were calculated by difference from total oxygen and nitrogen obtained from elemental analysis. Infrared absorbitivity values were determined from the OH and NH absorption bands of these asphaltenes and found to give linear correlations with the weight percentages of OH and pyrrolic nitrogen:. © 1979, American Chemical Society. All rights reserved.