Pervaporative poly(vinyl alcohol)/H-β zeolite mixed matrix membranes for dewatering C2-C3 alcohols

In present work, mixed matrix membranes (MMMs) of poly(vinyl alcohol) (PVA) and porous H-beta zeolite have been thoroughly studied for concentrating ethanol, n-propanol and isopropanol aqueous solutions via dewatering pervaporation. The effects of the zeolite content, feed composition and temperature on pervaporation flux/separation factor and permeance/selectivity are examined in detail for three alcohols. Experimental results show the H-beta zeolite addition has achieved more pronounced permeation flux and better separation efficiency than pure PVA counterpart, mainly attributed to the zeolitic pore size and hydrophilic feature. The MMMs have led to satisfactory permeation flux and separation factor and these results may be analyzed from the perspectives of the driving force, Hansen solubility parameter parameters and Flory-Huggins interaction parameter. The separation factor generally follows the sequence of isopropanol > n-propanol > ethanol according to the reverse order of their molecular sizes and polarities. The MMM of 20 wt% zeolite loading has performed stably over 144 h at 60 degrees C, and achieved separation factors of 1204, 1391, and 1645 and total fluxes of 719, 702, and 684 g/m(2) h from the 10 wt% water feed for isopropanol, n-propanol and ethanol, respectively. Therefore, the PVA/H-beta zeolite MMMs are technologically promising for alcohol dehydration applications.