PERVAPORATION DEHYDRATION OF ISOPROPANOL USING BLEND MEMBRANES OF SODIUM ALGINATE (SA) AND HYDROXY PROPYL CELLULOSE (HPC)

Abstract

Sodium alginate (SA) and Hydroxy propyl cellulose (HPC) blend membranes(SA/HPC) were prepared by solution casting method, followed by crosslinking with gluteraldehyde (GA), were tested for the pervaporation (PV) dehydration of isopropanol. The blend membranes were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (X-RD) to assess intermolecular interactions and crystallinity. Thermo gravimetric analysis (TGA) confirms that the stability increased with increase of SA content in SA / HPC blend membranes. The morphology of membranes was characterized by SEM studies, to confirm the chemical interaction and compatibility of these blend membranes. Sorption studies were carried out to evaluate the extent of interaction and degree of swelling of the membranes, in pure liquids as well as in mixtures of water and isopropanol. Pervaporation dehydration using crosslinked SA-HPC blend membranes were evaluated by the varying experimental parameters i.e., feed composition and membrane thickness. It was found that blend membrane containing 20 wt% HPC (SA-HPC-20) gave a high selectivity of 1314 and that the flux is of 0.1884 Kg /m2 h for 10 wt % water containing feed mixture. Comparatively, a low selectivity of 607 was observed for pristine cross linked SA membrane with the same feed mixture. Flux of the pristine SA membrane increased from 0.092 to 0.137 Kg / m2h. For SA-HPC-20 membranes, flux increased from 0.1884 to 0.2879 Kg / m2h over the studied feed water compositions of 10-17.5 wt%. From the above results, it is concluded that the present blend membranes are a promising candidates for Pervaporation dehydration of isopropanol.