Current status and prospects of demetallization of heavy petroleum feedstock (Review)

Comparative assessment of the prospects of development of heavy petroleum feedstock (HPF) upgrading technologies in terms of the possibility of removal and recovery of metals contained in the feedstock is presented. It has been shown that HPF demetallization with different efficiencies can be achieved as a result of destructive thermal conversion of the feedstock and nondestructive mass transfer processes. Solvent deasphalting is characterized by simplicity of engineering design and operating flexibility and makes it possible to remove both asphaltenes and metals, whose deposition leads to irreversible deactivation of oil refining catalysts. Promising lines in demetallization by destructive feedstock conversion are associated with processes that provide the highest degree of HPF conversion and the lowest yield of the unconverted residue, in which the feedstock metals are concentrated. In this regard, the development and implementation of petroleum residue upgrading technologies based on the slurry hydrocracking, fluid coking or flexicoking, and supercritical fluid extraction processes creates real prerequisites for the organization of high-conversion comprehensive processing of heavy oils with the isolation of a metal concentrate.