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Pervaporation (PV) separation of toluene/n‐heptane mixtures was studied experimentally and theoretically by means of a molecular surface engineering (MSE) polymer composite membrane. A comprehensive mathematical model was developed to predict unsteady state transport of toluene and n‐heptane (nC7) through the membrane. Conservation equations including continuity, and heat transfer equations were solved using finite element method (FEM). Computational fluid dynamics (CFD) technique was applied to solve the model equations. The model was then verified with PV experimental data. The simulation results were in good agreement with the experimental data. The simulation results revealed that the proposed model could provide a general simulation of transport in the PV process. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers

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La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3−δ nanopowder, synthesized via an autocombustion technique, was pressed into disk-shaped membranes. Results of permeation experiments revealed that oxygen permeation flux increases as temperature, feed side oxygen partial pressure, and feed and sweep gas flow rates increase, while it decreases with membrane thickness and permeate side oxygen partial pressure. A Nernst−Planck based mathematical model, including surface exchange kinetics and bulk diffusion, was developed to predict oxygen permeation flux. Considering nonelementary surface reactions and introducing system hydrodynamics into the model resulted in an excellent agreement (RMSD = 0.0344, AAD = 0.0274 and R 2 = 0.9960) between predicted and measured fluxes. Feed side surface exchange reactions, bulk diffusion, and permeate side surface exchange reaction resistances are in the range of R ex ′ = 7 × 10 3 to 9 × 10 6 , R diff = 1 × 10 5 to 2 × 10 7 , and R ex ″ = 1 × 10 4 to 2 × 10 7 (s/m), respectively. The permeation rate-limiting step was determined using the membrane dimensionless characteristic thickness.

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