Pervaporation Separation of Water/2-Propanol Mixtures by Use of the Blend Membranes of Sodium Alginate and (Hydroxyethyl)cellulose:  Roles of Permeate−Membrane Interactions, Zeolite Filling, and Membrane Swelling

Abstract

In an effort to improve membrane performance of pristine sodium alginate (NaAlg) for 2-propanol dehydration, blend membranes of NaAlg with (hydroxyethyl)cellulose (HEC) (5, 10, and 20 mass %) were prepared. Membranes were prepared by solution casting and cross-linked by a twostage process as confirmed by Fourier transform infrared spectroscopy. The blend membrane of NaAlg with 10 mass % HEC gave the highest selectivity of 63 000 for 5 mass % water in feed mixture (highest selectivity achieved so far in the literature) by removing 99.97% of water, giving a flux of 0.04 kg/m 2 ‚h. Incorporation of ZSM-5(40) zeolite in the blend membrane increased flux without affecting selectivity. Swelling results are used to study the membrane-solvent interactions. Sorption and diffusion selectivity values were computed from experimental data, which were comparable with the theoretically calculated values obtained from thermodynamic treatment based on Flory-Huggins theory.

Novel sodium alginate/polyethyleneimine polyion complex membranes for pervaporation dehydration at the azeotropic composition of various alcohols

“…It is observed that PIC membranes offered superior performance compared to other polymeric membranes 20,41 -48 and hence these could be effective in dehydrating isopropanol from the aqueous streams; zeolite membranes offered better results due to molecular sieving action. 47,48 Evaluation of the performance of the PIC membrane incorporated with zeolite forms the future course of our work. …”

Separation of acid–water mixtures by pervaporation using nanoparticle filled mixed matrix copolymer membranes

“…Further, it also improves mechanical properties of the membranes. Among the various adsorbents zeolite, 7,10,25 metal oxides, 4 sodium montmorillonite (Na-MMT), 24,26,27 etc., have been tried for making MMM. Incorporation of nanosize fillers as adsorbent in dense membrane improves its performance (normalized flux and selectivity) in both gas separation and pervaporation for several types of feed mixtures.…”

Pervaporation Dehydration of Ethanol Using Nanocomposite Membranes Prepared from Poly(vinyl alcohol) and Poly(vinylpyrrolidone) Blends Incorporated with Cellulose Nanocrystals

“…Double-distilled water was used throughout the experiments. Cellulose whiskers extracted from cotton linters were prepared by acid hydrolysis 8 performed using 64-65% (w/w) sulfuric acid (10 mL/g of cellulose) at 45 o C for about 60 min by arresting the reaction after diluting with cold water. The suspension was washed by centrifugation at 4900 rpm for 15 min at 25 o C, which was dialyzed using a dialysis pouch.…”