97/00970 Solvent recyclability and hydrotreatment severity in direct liquefaction of low-rank coal

Abstract

A multistep direct liquefaction process specifically aimed at low-rank coals (LRCs) has been developed at the Energy & Environmental Research Center (EERC). The process consists of a preconversion treatment to prepare the coal for solubilization, solubilization of the coal in the solvent, and polishing using a phenolic solvent or solvent blend to complete solubilization of the remaining material. The product of these three steps can then be upgraded during a traditional hydrogenation - step. Research was performed to address two questions necessary for the further development and scaleup of this process: (1) determination of the recyclability of the solvent used during solubilization, and (2) determination of the minimum severity required for effective hydrotreatment of the liquid product. The research was performed during two tasks, the first consisting of ten recycle tests and the second consisting of hydrotreatment tests performed at various conditions.