Model pervaporation membrane reactor

B. Park, Models and Experiments with Pervaporation Membrane Reactors Integrated with a Water Adsorbent System, Ph.D Thesis, University of Southern California, Los Angeles USA, 2001. 

The first pervaporation membrane reactor model which takes into account solution non-idealities was developed and validated experimentally by Zhu et al [5.90]. Prior studies [5.89, 5.91] also made note of such non-idealities, but offered no unified means for accounting for these phenomena in the description of PVMR. Since the model of Zhu et al. [5.90] appeared, other groups have also utilized similar models [5.92]. A more comprehensive analog of this model was, for example, recently presented and validated experimentally by Park [5.93], and by Lim et al. [5.94]. Zhu et al. [5.90] analyzed a tubular PVMR, in which the homogeneously catalyzed esterification reaction of acetic acid with ethanol to produce ethyl acetate and water took place. The reaction can be expressed generally as ... 

The following assumptions were made in developing the equations for the model for the plug-flow pervaporation membrane reactor (PFPVMR) The reactor behaves as an... 

Park B-G and Tsotsis T T (2004), Models and experiments with pervaporation membrane reactors integrated with an adsorbent system , Chem Eng Process, 43,1171-1180. 

Hasanoglu, A., Dinger, S. (2011). Modelling of a pervaporation membrane reactor during esterification reaction coupled with separation to produce ethyl acetate. Desalination and Water Treatment, 35, 286—294. 

An early model describing the pervaporative reaction of acetic acid with ethanol was presented by Krupiczka and Koszorz (1999). It was a simple, three-parameter model describing the concentration profiles in the process (a kinetic approach was considered) in the form of three differential equations. The activity coefficients were calculated using the UNIFAC property method. A hydrophilic membrane PERVAP 1005 GFT was used. Differently, Tanna and Mayadevi (2007) developed a two-step series model to study the performance of the membrane reactor. In this case, the goal was the assessment of the parameters that drive the process. As a conclusion of this work, the authors suggested using a low-flux membrane with a sufficient surface area when designing a PVMR. 

In spite of the growing research effort, with the exception of fuel cells, there are only a few examples of industrial applications of non-biocatalytic polymeric membrane reactors, such as the Remedia Catalytic Filter System for the destruction of dioxins and furans from industrial combustion sources or pervaporation-assisted esterification processes. More research is required in order to find long-lasting high-performance and cheap polymeric materials and catalysts that can effectively compete with the traditional processes. On pursuing this quest, mathematical modelling and simulation are fundamental tools for the better understanding of membranes behaviour and optimization. 

Based on experimental results and a model describing the kinetics of the system, it has been found that the temperature has the strongest influence on the performance of the system as it affects both the kinetics of esterification and of pervaporation. The rate of reaction increases with temperature according to Arrhenius law, whereas an increased temperature accelerates the pervaporation process also. Consequently, the water content decreases much faster at a higher temperature. The second important parameter is the initial molar ratio of the reactants involved. It has to be noted, however, that a deviation in the initial molar ratio from the stoichiometric value requires a rather expensive separation step to recover the unreacted component afterwards. The third factor is the ratio of membrane area to reaction volume, at least in the case of a batch reactor. For continuous opera-... 

---