“…Detailed studies have been carried out to understand the mechanism of coal particle dissolution (Guin et al, 1976; Wen, *Department of' Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania I526 1. 1979;Han et al, 1978;Oele et al, 1951;Plett et al, 1977) and the roles of the donor solvent (Gliem, 1976;Kang et al, 1976;Neavel, 1976), molecular hydrogen (Vernon, 1980) and inorganic mineral matter (Gangwer and Prasad, 1979;Given et al, 1975;Gray, 1978;Guin et al, 1978Guin et al, , 1979aJackson et al, 1979;Mukherjee and Choudhary, 1976;Rottendorf and Wilson, 1980) in the coal liquefaction process. The mechanism of the liquefaction process has also been studied by many investigators (Brunson, 1979;Cronauer et al, 1978;Curran et al, 1967;Hill et al, 1966;Libenberg and Portgieter, 1973;Oele et al, 1951;Petrakis and Grandy, 1980;Ruether, 1977;Vernon, 1980;Wiser, 1968Wiser, , 1971Gun et al, 1979).…”