PROCESS FOR REMOVING METHANE FROM A GAS

摘要

The invention relates to a method for removing methane from feed gas having a methane concentration of 2 mole pcnt or less, said method comprising the steps of: - (a) optionally mixing the feed gas with make-up methane or make- up air; - (b) passing the feed gas and optional make-up gas through a heat exchanger to raise the temperature of the gas to the desired inlet temperature T1 of an oxidation reactor; - (c) passing the heated stream from step (b) to the oxidation reactor containing an oxidation catalyst, where the methane is oxidised; - (d) removing a gas stream including the products of the oxidation reaction from the reactor, said gas stream being at an outlet temperature T2 which is higher than the inlet temperature T1; - (e) passing the gas stream removed in step (d) through the heat exchanger against the reactor stream from step (b) to allow the heat to be recovered from the gas stream removed in step (d) and utilised to heat the reactor stream in step (b); and - (f) measuring the outlet temperature T2 and controlling the inlet temperature T1 by adjusting the relative amount of make-up methane and/or make up air added in step (a) - alternatively, instead of steps (a) and (f) the following steps can be included in the method: - (b2) optionally by-passing a portion of the feed around the heat exchanger with optional make-up air; - (f2) measuring the outlet temperature T2 and controlling the inlet temperature T1 by adjusting the amount of feed bypassing the heat exchanger.