Solvent makeup in solvent extraction of coal

Abstract

A coal liquefaction process is provided in which a hydrogen donor solvent is used to at least partially liquefy the coal. The process is maintained in hydrogen donor solvent balance by treatment of selected products obtained in the course of the coal liquefaction process. The required balance is achieved by a series of inter-related operations performed on a hydrofined portion of a solids-free fraction of the coal extract. The inter-related operations include the recovery of an aromatic hydrocarbon-rich portion from the solids-free fraction by selective recovery from the solids-free fraction and from the products of a catalytic cracking operation wherein the remaining portion of the solids-free fraction is used as a feedstock. The aromatic hydrocarbon-rich portion boils within the range of the hydrogen donor solvent, and serves as makeup solvent for the required maintenance of solvent balance.

Description