Process for preparing methane rich gases

Abstract From the Canadian patent

Hydrogen and carbon oxides are reacted to form methane by passing an inlet stream of preheated methanation synthesis gas together with a recycle stream of product gas through a catalyst bed is a adiabatic methanation reactor. The inlet temperature is between 250 and 350°C, the outlet temperature between 500 and 700°C. The recycle stream is withdrawn from the outlet stream after the latter has been cooled to a temperature between 250 and 350°C and being, however at least 50°C above, the dew point. A preferred means for withdrawing the recycle stream is an ejector driven by the inlet stream or by added steam.