Cellulose acetate/nanoclay composite membranes with enhanced mechanical properties and improved permeance in gas separation

Diethyl ether is a valuable chemical product in petrochemical industry used in different applications. In diethyl ether (DEE) production by the dehydration of ethanol (EtOH), the products from DEE production are commonly mixed with EtOH and the % yield of DEE generally has not exceeded 60%. This contribution describes the preparation and performance of hollow fiber membranes for the separation of gaseous product (DEE) and reactant (EtOH). Cellulose acetate (CA)/nanoclay (NC)-based hollow fiber composite membranes were prepared using a wet spinning process of CA solution and the addition of hydrophilic NC particles to improve the mechanical properties and permeability. According to the findings, the 20 wt% CA/0.5 wt% NC hollow fiber showed the higher mechanical strength than the 20 wt% CA hollow fiber without NC. Moreover, the 20 wt% CA hollow fiber without NC provided EtOH and DEE permeances of 8.44 x 10(-11) and 4.25 x 10(-10) mol m(-2) s(-1) Pa-1, respectively, while the 20 wt% CA/0.5 wt% NC hollow fiber showed higher EtOH and DEE permeances of 6.50 x 10(-10) and 8.49 x 10(-9) mol m(-2) s(-1) Pa-1 plausibly because of the higher porosity based on the SEM images. Furthermore, both CA hollow fiber membranes were selective for DEE over EtOH and were more selective with the addition of NC.