摘要 |
A process for removing carbon dioxide from a gas stream containing hydrogen, carbon monoxide and carbon dioxide comprising subjecting the gas stream to a first stage high-temperature selective catalytic methanation to lower the carbon monoxide concentration in the gas but not below a concentration which allows carbon dioxide methanation to take place, followed by a second stage low selective catalytic methanation to lower the residual carbon monoxide in the gas stream to a concentration of below 40 ppm. The high temperature methanation is suitably carried out at a temperature of between 250° C. and 350° C., and the low temperature methanation is suitably carried out at a temperature below 270° C. |