Separation of butane isomer by tubular silicalite-1 zeolite membrane

The permeation properties of n-butane, i-butane and n-butane/i-butane mixture （n-butane 24.3% （molar ratio）, i-butane 75.7%） through a tubular silicalite1 zeolite membrane were studied at 298 and 473 K respectively. The permselectivities of n-butane and i-butane under pressure difference of 0.06 MPa at 298 and 473 K were 16.3 and 7.4 respectively. The separation factors of n-butane/i-butane mixture were between 2.0 and 2.5 at 298 and 473 K. At 298 K, the permeances of n-butane in the mixture were lower than those of single component while the permeances of i-butane in the mixture were almost the same as those of single component. At 473 K, the permeances of n-butane and i-butane in the mxiture were decreased compared with those of the single component, and the permeance of n-butane decreased more rapidly than that of i-butane.