Method for removing carbon dioxide from mixed gas and alternative natural gas production apparatus using the same

摘要

The present invention provides a method of removing carbon dioxide from a mixed gas containing methane and carbon dioxide by the PSA method using a plurality of adsorption tanks filled with CMS. The above described PSA method includes at least an adsorption step, a desorption step and a boosting step. According to the carbon dioxide removal method of the present invention, the initial stage of the desorption step is characterized by the recovery stage for recycling 20% to 40% of the amount of the desorption gas to the raw material gas. The pressure of the adsorption step is preferably set to 5 kg / cm. Sup. 2 g or more and less than 10 kg / cm. Sup. 2 g, and the final pressure of the desorption step is preferably set to 100 torr to 20 Torr. The carbon dioxide removal method of the present invention is preferably incorporated into an alternative natural gas production process.