To provide a method for producing substitute natural gas(SNG), capable of addressing or reducing the problems involved in carbon dioxide separation by PSA method while making the best use of the advantages of the method.
A methane-rich gas is recovered by PSA method designed to adsorb and separate the carbon dioxide in a mixed gas comprising methane, carbon dioxide, carbon monoxide and hydrogen through repeated adsorption/ desorption. In this method for producing the objective SNG, the reducing pressure in desorbing the methane-rich gas is controlled according to the operation load [specifically, the final reducing pressure in the above desorption is controlled within the range between -0.2 and -1.0kg/cm2(G)] so that the carbon dioxide concentration in the methane-rich gas after separated.
MORIMOTO MASAHIKO
MOTOE MASASHI
INOUE MASAHIRO
HARUNA KAZUO
SUMITOMO SEIKA CHEMICALS