Process for separating aggressive gases from gas mixtures

摘要

A process for separating large percentages of aggressive gases such as carbon dioxide from low temperature gas mixtures wherein the gas mixture is passed through a plurality of treatment zones in series. In each treatment zone the gas mixture is first compressed to a pressure such that the partial pressure of the carbon dioxide is not greater than the critical carbon dioxide partial pressure and the compressed gas mixture is then brought into contact with a membrane more permeable to carbon dioxide than other gases of the mixture such that carbon dioxide permeates the membrane to the other side thereof. The gas mixture is maintained in contact with the membrane a sufficient time to lower the partial pressure of the carbon dioxide in the non-permeated gas mixture to less than about 40 percent of said critical carbon dioxide partial pressure. The process is especially useful for separating carbon dioxide from methane and other gases.