SEPARATION OF A CO2 H-2 GAS-MIXTURE UNDER HIGH-PRESSURE WITH POLYETHYLENE TEREPHTHALATE MEMBRANES/

Recently compressed carbon dioxide is brought in as a substitute for c onventional solvents in the chemical industry. To meet economic and ec ologic demands it is necessary to recycle the CO2 in a circuit and it is therefore necessary to remove undesired components (e.g. unconverte d H-2 from hydrogenation reactions). This study deals with the purifyi ng of carbon dioxide under high pressure by means of gas permeation. F or the separation of H-2 from a CO2/H-2 gas mixture under high pressur e a polyethylene terephthalate membrane is employed. The influence of temperature and feed gas pressure on the permeability coefficients and separation factors of carbon dioxide and hydrogen is reported. The in vestigations were made within a temperature range of 10 to 70 degrees C and a pressure up to 190 bar.