Chemical Structure Analysis of Shengli Crude Vacuum Residuum Related to Thermal Conversion

摘要

Thermal conversion processes, for example delayed coking and visbreaking etc., are commonly used in the refinery today to convert heavy ends of crude oils into distillable liquid products. One troublesome problem of these thermal processes is the simultaneous formation of coke due to the defined H/C atomic ratio of the reaction system, which causes either the decreased yields of distillable liquid products or heater and/or reactor fouling. Resins and asphaltenes present in petroleum residue are believed to be the main contributors to coke formation due to their high aromatic character (1, 2). Many intermediate coke precursors are formed during the conversion of resins and asphaltenes into coke. Analysis of the chemical structure changes of resins and asphaltenes before and after thermal conversion and the chemical structure of coke precursors is helpful to elucidate the mechanism of coke formation, thereby providing basic knowledge to control coking reaction and improve the thermal processing technology of petroleum residue.