GB1461280A - Refining of carbonaceous fuels - Google Patents

Abstract

1461280 Extracting coal GULF OIL CORP 19 Feb 1974 7499/74 Heading C5E Ash-free solid carbonaceous fuel is produced by digesting coal in an aromatic solvent at 700-950‹ F. and 500-5000 p.s.i.g. in contact with 1À5-40 SCF of carbon monoxide and 0À2- 1À5 pounds of steam per pound of dry coal, separating the undissolved portion of the coal from the solution and recovering the ash-free solid fuel from the solution; the conditions during the digestion are such that the relative viscosity of the solution measured at 210‹ F. rises to a value at least 20 times that of the solvent alone (due to extraction of carbonaceous fuel from the coal) and then falls to a value of below 10 (due to depolymerization of the extracted fuel) and would then permit the relative viscosity of the solution to again rise above 10 with increased dissolving time (due to repolymerization) except that such conditions are terminated before the relative viscosity again rises to above 10. Ground coal 2 is slurried in a solvent 3, mixed with a carbon monoxide and steam-containing gas from line 8 and passed through the preheater 5 and a digestion vessel 6. Alternatively steam can be provided by water contained in the coal and the gas can also contain hydrogen. The mixture is filtered at 10 to produce a residue 16 from which residual solvent can be removed and recycled, a gas stream 11 which is recycled via a scrubber 12 and a solution 20. The solution is heated at 21 and flashed under vacuum at 23 to provide ashfree liquid fuel 29 which is solidified at 30 and a gaseous stream 24 which is separated at 25 to provide the recycle solvent 26. The possibility of using anthracene oil or creosote oil as the solvent is referred to.