GB1481958A - Supercritical extraction and concurrent catalytic hydrogenation of coal digests - Google Patents

Abstract

1481958 Hydrogenated coal extracts COAL INDUSTRY (PATENTS) Ltd 8 Nov 1974 [12 Dec 1973] 57610/73 Heading C5E Coal-derived materials are treated by contacting with hydrogen (e.g. at a partial pressure of 30-300 atmospheres) in the presence of a solvent which is above its critical temperature and a catalyst comprising a salt or oxide of a metal other than a noble metal, separating the solvent from the residue and condensing the hydrogenated products from the vaporous solvent, the treatment being carried out at a pressure such that the sum of the reduced partial pressures of those solvent components which are above their critical temperature is at least one. The coal-derived material can be a heavy tar produced by carbonization or hydrogenation of coal, a dispersion prepared by heating coal to above 200‹ C. in a heavy aromatic oil or a hydrogen donor solvent, or a solution obtained by filtering such a dispersion. The catalyst can comprise W, Mo, Co and/or Ni on silica or alumina and can be maintained in a sulphided form or it can be a salt of Sn, Zn, As, Sb, Bi, Ti, Ga or Hg. The solvents listed comprise water, phenols, pyridine, cycloaliphatic hydrocarbons, benzene, alkyl benzenes, C 5-16 acyclic aliphatic hydrocarbons and aromatic hydrocarbons having two aromatic rings; the solvent used can comprise components which have critical temperatures which are above the reaction temperature. In examples, the reaction is carried out by heating a solution, produced by dissolving coal in anthracene oil, filtering and distilling some of the oil from the solution, with toluene, anhydrous zinc chloride and hydrogen in an autoclave at 400‹ C.