Novel approach to determination of sorption in pervaporation process: a case study of isopropanol dehydration by polyamidoimideurea membranes

Abstract

Development of novel membranes with optimal performance, selectivity, and stability is a key research area in membrane technology. In the present work aromatic polyamidoimideurea (PAIU) is synthesized and tested as promising membrane material for separation of water and alcohol mixtures. The PAIU membrane structure, density, and transport properties are studied. Mass transfer of water and isopropanol through the membrane is estimated by sorption and pervaporation tests to determine equilibrium sorption degree, diffusion coefficients, flux through the membrane, and separation factor. Two techniques of sorption study from liquid and from vapor phases are used as novel approach to experimental study of mass transfer. The vapor sorption calorimetry permits to analyze the behavior of the polymer material in sorption process. In pervaporation of water–isopropanol mixture, almost pure water mainly permeates through PAIU membrane. To improve the performance, a double layer membrane containing a thin PAIU layer on the surface of porous poly(phenylene oxide) support is developed. The double layer membrane is extremely effective in dehydration of isopropanol.

Novel Polyheteroarylene Membranes for Separation of Methanol‒Hexane Mixture by Pervaporation

“…However, the experience showed that such membranes contain residual amounts of NMP solvent. In order to eliminate the influence of residual solvent (NMP) on membrane properties, the obtained membranes were subjected to the special treatment with methanol that displaces NMP and washes it out 23 . Membranes were immersed into methanol, left to stand for three days, then thoroughly washed with methanol, and dried at 40 о С in vacuum for two weeks 40–42 .…”

Modification of highly brittle polystyrene sulfonic acid‐co‐maleic acid crosslinked sodium alginate membrane into flexible membranes by the incorporation of dibutyl phthalate as a plasticizer for pervaporation separation

“…Thus, water molecules can be easily sorbed into the membrane matrix. [49] 3.9 | Pervaporation study 3.9.1 | Effect of azeotropic mixtures and wt% of DBP on PV Figure 11 demonstrates the effect of different wt% of DBP content on the total permeation flux and separation factor for the developed membranes at 30 C in dehydrating water/isopropanol and water/1,4-dioxane mixtures at their azeotropic point. It is observed that the permeation flux was increased from DBP-1 to DBP-4 owing to the increased plasticizing content, as discussed in the swelling study, and this is expected due to extensive hydrogenbonding interactions between the carbonyl oxygen and ester oxygen of DBP and OH group of NaAlg.…”

“…The transport of binary liquid mixtures through a nonporous polymeric membrane in the PV process is typically described by a solution-diffusion mechanism. [49] The rate of permeation and separation factor is determined by the solubility and diffusivity of each component of the feed to be separated. In the separation process, the diffusion step controls the transport of penetrants by establishing a fast equilibrium distribution between the bulk feed and the upstream surface of a membrane.…”

A Simple Methodology to Estimate the Diffusion Coefficient in Pervaporation-Based Purification Experiments

“…In spite of the various, complex methods for determining the diffusion coefficient, the researchers usually do not evaluate the value of diffusion coefficient but only estimate parameters that describe the effectiveness of investigated membranes (e.g., PSI , flux and separation factor) [ 17 , 18 , 23 , 24 , 25 , 26 ]. Much less frequently sorption and diffusion coefficients are considered [ 8 , 27 , 28 , 29 ], which requires additional experimental setups. Such approach is in contrast to what we can find in the analysis of permeation of gases where determination of D is crucial.…”