Modelling of Membrane Reactors

Q volumetric flow rate r radial coordinate rj. region I radius r i membrane radius rs-r support thickness Tpi pore radius 

T temperature U superficial fluid velocity U average fluid velocity V volume x molar fraction z axial coordinate 

Catalytic Membranes and Membrane Reactors. By J. G. Sanchez Marcano and Th. T. Tsotsis 

0 membrane reactor entrance or feed p pores S support T total 

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Several investigators have faced the problem of modeling of membrane reactors either to achieve a proper interpretation of their experimental data or to assess the role of the various operating parameters (temperature, membrane permeability and permselectivity, feed flow rates, and concentrations, etc.) on the performance of membrane reactors. In some other cases [61,138] modeling studies helped to point the way toward future experimental work concerning, e.g., the need for thinner or more permeable or more stable membranes to outperform conventional technologies for given applications. 

Hirt CW, Amsden AA, Cook JL (1974) An Arbitrary Lagrangian-Eulerian Computing Method for All Flow Speeds. J Comput Phys 14 227-253 Hoff KA, Poplsteinova J, Jakobsen HA, Falk-Pedersen O, Juhussen O, Svendsen HF (2003) Modeling of Membrane Reactor. International Journal of Chemical Reactor Engineering 1 1-12, Article A9, (http //www.bepress. com/ijcre/voll/articles.html)... 

In the previous section a one-dimensional model was developed and used to demonstrate the possible benefits of packed-bed membrane reactors as compared to the established fixed-bed reactors. Basic phenomena can be described with sufficient accuracy even with this simple model. However, when the goal is to predict reactor behavior in more detail the one-dimensional model may reach its limits due to radial mass- and heat-transfer limitations. Additionally, flow-maldistribution effects can also not be captured. Taking advantage of improvements in computation speed, it is nowadays possible to predict the influence of these phenomena with two- or even three-dimensional models and use this knowledge to optimize reactor performance. However, detailed modeling of membrane reactors is not as straightforward as in the case of fixed-bed reactors. There are still a couple of open questions e.g. whether semiempirical correlations obtained under nonreactive conditions in fixed beds are applicable also to membrane reactors or not. Until these questions have been completely clarified one has to rely on the available database and correlations as the best possible estimate. 

Modeling of Membrane Reactors for Hydrogen Production and Purification... 

Modeling of Membrane Reactors for Hydrogen Production and Purification and the energy balance for the solid phase is ... 

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