Palladium-based membrane reactor

Marigliano, G., Barbieri, G. and Drioli, E. (2001) Effect of energy transport in a palladium based membrane reactor for methane steam reforming process. Catalysis Today, 67 (1-3), 85-99. 

Catalytic Design of Palladium-Based Membrane Reactors... 

Depending on the type of catalyst adopted, the operating temperatures can vary between 600 K (low-temperature shift catalyst) and 700 K (high-temperature shift catalyst). Because of the relatively high temperatures employed, studies reported in the literature usually refer to the use of inorganic membrane reactors [13-16]. In particular, because palladium and its alloys are extremely selective to hydrogen, many reports discuss work on palladium-based membrane reactors. 

Both theoretical and experimental studies have been performed on palladium-based membrane reactors for the water-gas shift reaction. Ma and Lund simulated the performance achievable in a high temperature water-gas shift membrane reactor using both ideal membranes and catalysts [18]. By comparing the results obtained with those related to the existing palladium membrane reactors, they concluded that better membrane materials are not needed, and that higher performances mainly depend on the development of a water-gas shift catalyst not inhibited by CO2. Marigliano et al. pointed out how the equilibrium shift conversion in membrane reactors is an increasing function of the sweep factor (defined as the ratio between the flow rate of the sweep at the permeate side and the flow rate of CO at the reaction side) [19]. The ratio is an index of the extractive capacity of the system. 

Fig. 2.2 Number of publications per year on membrane reactors area and on restricted area on palladium-based membrane reactors...

Moreover, Fig. 2.2 points out further statistics data on palladium membranes applied in the field of membrane reactors (MRs), devices combining the separation properties of the membranes with the typical characteristics of catalytic reaction steps in only one unit. In particular, this figure reports the number of publications on palladium-based membranes reactors with respect to the total number of publications in the membrane reactors area. 

The applications and the research studies performed on this kind of reaction were realized by many scientists. In particular, a great literature is present on this issue concerning the use of palladium-based membrane reactors, as resumed briefly in Table 2.7, where CO conversion values obtained in MR and compared with the thermodynamic equilibrium ones of some scientific works are reported. In particular, among these works, Kikuchi et al. [115] demonstrated that, using a 20 pm layer of palladium-coated onto a porous glass tube produced by the electroless plating method, allows to obtain almost complete CO conversion. 

Shu J, Grandjean BPA, Van Neste A, Kaliaguine S (1991) Catalytic palladium-based membrane reactors a review. Can J Chem Eng 69 1036-1060... 

Shu, J., Grandjean, B. P. A., Neste, A. V., Kaliaguine, S. (1991). Catalytic palladium-based membrane reactors a review. Canadian Journal of Chemical Engineering, 69(5), 1036-1060. 

Computational fluid dynamics (CFD) analysis of membrane reactors simulation of a palladium-based membrane reactor in fuel cell micro-cogenerator system... 

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