GB337671A - An improved method for the destructive hydrogenation of carbonaceous materials - Google Patents

Abstract

337,671. Standard Oil Development Co., (Assignees of Jennings, J. M.). Dec. 21, 1928, [Convention date]. Hydrogenation, destructive.-In the destructive hydrogenation of heavy fluid asphalt-containing materials, such as crude oils, tars, cracked residues or suspensions of coal in oils by means of solid catalysts immune to sulphur poisoning, such as chromium or molybdenum oxides, coking is prevented by keeping the ratio of asphalt to catalyst in the material treated below a predetermined value which may be 1.5 but preferably is 0.5. The temperature employed is between 800' and 970‹ F. and the pressure above 25 atmospheres in an example 850‹ F. and 3,000 pounds per square inch are employed. The ratio between asphalt and catalyst is determined at intervals and if above the desired limit, fresh catalyst is placed in a closed vessel through which the flow of fresh material to be treated is diverted. Heating may be effected electrically but preferably part of the material undergoing treatment is continuously withdrawn, passed through a heating device and returned; vapourous products are continuously withdrawn. In the apparatus shown, the material is treated in a heat insulated drum 1, part of the charge being withdrawn through a pipe 3 and forced by a pump 4 through a furnace heated coil 5 and back through a pipe 7 into the drum 1. Hydrogen, or a gas rich in hydrogen, passes into the drum 1 from a branch 10 of a supply pipe 8 or through a branch 9 into the coil 5. Gas and vapours pass off from the drum 1 by a pipe 11 through heat exchangers 12, 13 to a condenser 14 and a separation drum 15 from which the condensate is conveyed by a pipe 16 to storage or to stills for removing low boiling constituents, the heavier oils being returned to the drum 1. Gas from the separator 15 is either removed by a pipe 30 or passes by a pipe 17 to a tower 18 where it is washed to remove gaseous or low boiling hydrocarbons by oil fed by a pump 20 through a pipe 21. Sulphuretted hydrogen is removed from the gas by an aqueous sodium hydrate or carbonate solution in a tower 19, the purified gas being returned by a pump 27 to the preheater 12 and passing by a pipe 28 to the feed pipe 8. Fresh hydrogen may be supplied by a pipe 29, and fresh oil is forced by a pump 32 through a pipe 31 into the preheater 13 and thence by pipes 33, 34, 37 to the pipe 3. New catalyst is supplied from a drum 36 which is connected by pipes 39, 37 to the pipe 3 and in its upper part by a valved pipe 35<1> to a valved sampling pipe 35 connected to the pipe 3. To prevent accumulation of ash in the system, the recirculated material may be withdrawn by pipes 35<1>, 37<1> and drum 36 or by suitable pipes not shown.