The removal of linear hydrocarbons from hydrocarbon mixtures using a silicalite-1 membrane has been demonstrated. The molecular sieving property of silicalite-1 membrane was evaluated by vapor permeation tests in unary systems using 15 hydrocarbons of various molecular sizes. The results of the unary permeation tests suggest that the permeance of each hydrocarbon strongly depends on its critical dimension. The hydrocarbon permeance through the silicalite-1 membrane can be explained by the ratio of the cross-sectional area of the molecules, calculated from their critical dimensions, to that of the micropore. Consequently, the silicalite-1 membrane exhibited superior n -alkane selectivity owing to the molecular sieving effect. For practical light oil, including C 8 -C 28 hydrocarbons with 26 wt% linear hydrocarbons, the silicalite-1 membrane successfully removed linear hydrocarbons with a flux of 0.662 L m −2 h −1 and a purity of 94 wt% at 673 K. The membrane performance was maintained even after >200 h of intermittent use for various hydrocarbon separation.
Sakai et al. (Mon,) studied this question.