GB1389981A - Preparation of methane-rich gas - Google Patents

Abstract

1389981 Methane rich gas METALLGESELLSCHAFT AG 3 Jan 1973 [3 Jan 1972] 429/73 Heading C5E A methane-rich fuel supply gas is prepared by cooling a rich gas containing less than 15% by volume hydrogen to below 150‹ C. to reduce its water vapour content, the condensate being withdrawn, preheating a first branch stream constituting 50 to 70% of the gas to at least 250‹ C. and passing it through a first layer of a hydrogenating catalyst, feeding a second branch stream of the gas at about the temperature to which the gas was cooled between the first layer and a second layer of the hydrogenating catalyst, passing the resulting mixture of the second branch stream of the gas and product gas from the first layer of catalyst through the second catalyst layer, and scrubbing the product gas leaving the second layer to remove carbon dioxide. The volume ratio of gas in the two branch streams is adjusted so that the temperature rise in the gas as it passes through the second catalyst layer is less than 50‹ C. and the product gas contains less than 1% by volume hydrogen. The rich starting gas may have been prepared from liquid hydrocarbons, e.g. gasoline feedstock, having 3 to 15 carbon atoms, corresponding to a boiling point range of 30‹ to 210‹ C. Examples of catalyst and CO 2 absorbers are given. Apparatus for producing the methane-rich gas comprises cooling means 15, 16 with condensate withdrawal means 17 for cooling rich gas from conventional reactor 1, a conduit 18 leading a first stream of cooled gas through heater 20 and a conduit 19 leading a second stream of cooled gas to a methanizing reactor 2 containing catalyst layers 3, 4 such that gas from conduit 18 passes through layer 3 prior to mixing with gas from conduit 19 and manifold 21 between layers 3, 4 and passing through layer 4. Conduit 22 leads gases leaving the reactor 2 through cooler 23 to conventional scrubber 5.