Pervaporation Separation of Xylene Isomers by Hybrid Membranes of PAAS Filled with Silane-Modified Zeolite

Abstract

Silicalite-1 zeolite was modified with 3-aminopropyltriethoxysilane (APTES) and then loaded into poly(acrylic acid) sodium (PAAS) to prepare PAAS/silicalite-1 hybrid pervaporation membranes for the separation of xylene isomer mixtures. Characterization by Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopies confirmed that chemical modification on the zeolite surface had taken place. Based on sorption equilibrium experiments, the diffusion coefficients of permeates in the membrane were obtained, and the order of the diffusion coefficients of xylene isomers was found to be D o < D m < D p . An investigation of the effects of the original versus modified zeolite loading on the pervaporation performance was performed. With the original zeolite, the permeation flux of the binary xylene mixtures showed little change, whereas the selectivity of the hybrid membrane exhibited some enhancement. After modification of the zeolite surface, the selectivity of the hybrid membrane was clearly improved, the permeation flux of the membrane decreased slightly, and the maximum separation factors of the p-/o-xylyne (R p/o ) and p-/m-xylene (R p/m ) mixtures were determined to be 2.62 and 2.68, respectively. The experimental results revealed that the modification promoted the compatibility of the PAAS and silicalite-1 zeolite interface.

Ultrasonic treatment of polyacrylic acid sodium/NaA zeolite hybrid membranes for the pervaporation dehydration of ethanol

“…A flat‐sheet membrane including the PAN support with an effective area of 18.1 cm 2 was used for the evaluation of water/ethanol separation performance. The experimental procedure was reported in detail in a previous publication . An aqueous solution of ethanol was continuously circulated from the feed tank to the upstream side of the membrane.…”

Silane‐modified NaA zeolite/PAAS hybrid pervaporation membranes for the dehydration of ethanol

“…20 First, a mixture of toluene (100 mL), APTES (6 mL), and NaA zeolite (1 g) was stirred in an enclosed N 2 environment at 110 C for 6 h. Then, the product was filtered with 250 mL of toluene and washed with 250 mL of ethanol to remove the unreacted silane. 20 First, a mixture of toluene (100 mL), APTES (6 mL), and NaA zeolite (1 g) was stirred in an enclosed N 2 environment at 110 C for 6 h. Then, the product was filtered with 250 mL of toluene and washed with 250 mL of ethanol to remove the unreacted silane.…”

“…20 An aqueous solution of ethanol was continuously circulated from the feed tank to the upstream side of the membrane. This process has been reported in the literature.…”

Zeolitic imidazolate framework-7 as an ultra-selective nanofilter for H2purification: atomistic simulation study

“…Polymeric membranes can be fabricated in a relatively easier way; however, their separation performance and mechanical strength need to be improved. It has been recognised that next-generation membranes preferably possess both high stability of inorganic building blocks and tunable functionality of organic moieties [6].…”