skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Direct liquefaction of low-rank coal. Final technical report, July 13, 1994--November 30, 1995

Technical Report ·
DOI:https://doi.org/10.2172/231895· OSTI ID:231895

A multistep direct liquefaction process specifically aimed at low- rank coals has been developed at the Energy & Environmental Research Center. 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. This project addresses two research 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 project was performed during two tasks: the first consisting of ten recycle tests and the second consisting of twelve hydrotreatment tests performed at various conditions. This project showed that the solvent could be recycled during the preconversion, solubilization and polishing steps of the multistep process and that lower-severity conditions can be used to successfully hydrotreat the product of the multistep process. The success of this project indicates that additional studies should be performed to evaluate the liquid-phase reactions taking place during batch tests in which the gas flow is continuous (i.e., the gas effects would be negligible). In addition, the entire multistep process (including hydrotreatment) should be evaluated during continuous unit operations. 2 refs., 11 figs., 27 tabs.

Research Organization:
Univ. of North Dakota, Grand Forks, ND (United States). Energy and Environmental Research Center
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
FG22-94PC94050
OSTI ID:
231895
Report Number(s):
DOE/PC/94050-T6; ON: DE96010952
Resource Relation:
Other Information: PBD: Feb 1996
Country of Publication:
United States
Language:
English