SEPARATION OF CFC-12 FROM AIR BY POLYIMIDE HOLLOW-FIBER MEMBRANE MODULE

The performance of a polyimide membrane module was investigated for th e separation of air/CFC-12 mixtures as a function of temperature, pres sure, stage cut, and feed gas composition. The ideal separation factor was in the range of 60 to 200 in the ranges of temperature and pressu re studied. There was a substantial decrease in the permeation rates o f the more permeable gas (air) through the glassy polymer (polyimide) caused by the presence of the other gas (CFC-12). However, the permeat ion rate of CFC-12 (dichlorodifluoromethane, CCl2F2), which is the les s permeable gas, was increased by the presence of the more permeable g as (air). It was found that experimental data were well correlated wit h prediction of mathematical models.