Comparison of pervaporation models with simulation of hybrid separation processes

Nóra Valentínyi,Péter Mizsey

doi:10.3311/ppch.7120

Abstract

The industrial application of pervaporation as a membrane separation technology is increasing caused by the numerous advantages of this method. However, to complete engineering design, like in the cases of distillation, azeotropic distillation and absorption, reliable and adequate modelling of the process in flowsheeting environment is indispensable. A proper model is especially needed if the more complicated but more economical and environmentally sound hybrid separation methods are designed or investigated.In this study two pervaporation models, the solution-diffusion model of Rautenbach [1] and its developed form [2], are compared and evaluated with computer simulation on the dehydration processes of isobutanol-water and ethanol-water mixtures. Simulations of a hybrid separation method containing pervaporation for the separation of these mixtures are performed, thus proving the importance of using a proper pervaporation model regarding the discrepancies caused by the application of a false model.

Highlights

Pervaporation is a still underestimated but continually developing membrane technique suitable for the separation of special liquid mixtures [1,3,4,5]
Though the process was already mentioned in the early 20th century, first major research efforts were made by Binning et al in the 1950s at the American Oil Company in Texas, mostly for the separation of organic mixtures in the petrochemical industry [12]
5 Results and Discussion 5.1 Simulation Results Results of the simulations with both models are listed in Tables 2 and 3, where F stands for feed flow rate of the distillation column; FPV is the feed flow rate to the first membrane module, R is the retentate flow rate leaving the last module; P is the recycled permeate flow rate, Qreb represents the heat requirement of the reboiler of the column, QPV is the sum of the heat demand of the pervaporation units, wi is the isobutanol content of the retentate leaving the last module, ww is the water content of the recycled permeate flow in weight percent

Summary

Introduction

Pervaporation is a still underestimated but continually developing membrane technique suitable for the separation of special liquid mixtures [1,3,4,5]. Tion, etc.) form the so-called hybrid separation processes that The driving force of the component transport is difficult to are feasible and cost-effective solutions [16,17]. For adequate design and operation, proper Composite membranes in most cases consist of two polymer modelling of the pervaporation process is inevitable. The proposed semi empirical solution-difmodel in these software environments the design and optimiza- fusion model is suitable for the description of transport through tion of the individual membrane module and a complex hybrid a composite membrane. In this model the pressure in the memsystem is attainable.

Models of pervaporation pendence

Results and Discussion

Conclusions