GB712744A - Improvements in the production of gases rich in hydrocarbons - Google Patents

Abstract

712,744. Producing gases rich in hydrocarbons. GAS RESEARCH BOARD. Oct. 31, 1952 [Feb. 10, 1950]; No. 3516/50. Class 55 (1) In a process for producing gases rich in hydrocarbons particulate coal or other carbonizable material is hydrogenated in a fluidized state in a current of a hydrogen-containing gas at a temperature of about 800‹ C. or higher and under superatmospheric pressure, and a part of the resulting hydrocarbon-rich gas is catalytically reacted with steam to produce the hydrogencontaining gas for the hydrogenation. The hydrogenation may be conducted in a single fluidized or in two or more fluidized zones as described in Specification 695,192. The heat required for the catalytic conversion of the hydrocarbon-rich gas may be obtained by converting the solid residue from the hydrogenation into producer gas and using the producer gas to heat the vessel containing the catalyst. As shown in the drawing particulate coal is fed into a fluidized hydrogenation zone 2 maintained at a pressure of 25 atmospheres. The resulting gases rich in hydrocarbons pass successively through a cyclone separator 3, a condenser 4, a purifier 5, a heat exchanger 6 to an expansion turbine 7 where the pressure of the gases is reduced to about 10 atmospheres. The gases then are again heated in a heat exchanger 8 and finally expanded to near atmospheric pressure in a second turbine 9 to be withdrawn in part through a line 10 and in part to be used to produce the hydrogen-containing gas required for the hydrogenation in zone 2. This latter portion of the gas is mixed with steam through a line 12 and heated in a heat-exchanger 15 before passing through a series of tubes 14 containing a suitable catalyst, the tubes being arranged in a chamber 13 and heated externally by producer gas obtained by gasifying solid residue withdrawn by line 17 from the hydrogenation zone 2 in a producer 16. The hot combustion products of the producer gas are passed through a waste heat boiler 18 to generate the steam required for the process the steam being expanded in a turbine 20 before it is mixed with the hydrocarbon-containing gas through line 12. The hot hydrogen-containing gas passes through heat exchangers 15, 6 and 8, a condenser 21, a first stage compressor 22, a washer and cooler 24 for removing carbon dioxide and a second compressor 23 where the gas is raised to the pressure at which the zone 2 is operating. The passages through which the hydrogen-containing gas passes in heat exchangers 15, 6 and 8 may contain a catalyst capable of promoting reaction between undecomposed steam and carbon monoxide to increase the hydrogen content of the gas. The compressors 22 and 23 are driven by turbines 9 and 7 respectively. The hydrogenation in the zone 2 is controlled so that the total yield of hydrocarbon-rich gas may amount to 300 therms or more per ton of coal treated.