Palladium-based membranes Membrane Reactor

Barbieri, G, Violante, V. DiMaio, F. Criscuoli, A. Drioli, E. Methane Steam reforming Analysis in a Palladium-Based Catalytic Membrane Reactor Ind. Eng. Chem. Res. 36 (1997) 3369-3374. 

Barbieri G, Violante V, Di Maio FP, Criscuoh A, and Drioh E, Methane steam reforming analysis in a palladium-based catalytic membrane reactor, Ind. Eng. Chem. Res. 1997 36 3369. 

Sato K., Hamakawa S., Natsui M., Nishioka M., Inoue T., Mizukami F. 2010. Palladium-based bifunctional membrane reactor for one-step conversion of benzene to phenol and cyclohexanone. Catalysis Today 156(3-4) 276-281. 

Sato, K., Hamakawa, S., Natsui, M., et al. (2010). Palladium-Based Bifunctional Membrane Reactor for One-Step Conversion of Benzene to Phenol and Cyclohexanone, Catal. Today, 156, pp. 276-281. 

Figure 8.17 Palladium-based membrane shift 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. 

The unusual interaction of hydrogen with palladium-based membrane materials opens up the possibility of oxidative hydrogen pump for tritium recovery from breeder blankets. The feasibility for this potential commercial application hinges on the hot-fusion and cold-fusion technology under development [Saracco and Specchia, 1994]. At first, Yoshida et al. [1983] suggested membrane separation of this radioactive isotope of hydrogen followed by its oxidation to form water. Subsequently, Hsu and Bauxbaum [1986] and Drioli et al. [1990] successfully tested the concept of combining the separation and reaction steps into a membrane reactor operation. 

Catalytic Design of Palladium-Based Membrane Reactors... 

Dense palladium-based membranes. Shown in Table 10.1 are modeling studies of packed-bed dense membrane shell-and-tube reactors. All utilized Pd or Pd-alloy membranes except one [Itoh et al., 19931 which used yttria-stabilized zirconia membranes. As mentioned earlier, the permeation term used in Ihe governing equations for the tube and shell sides of the membrane is expressed by Equation (10-51b) with n equal to 0.5 [c.g., Itoh, 1987] or 0.76 [e.g., Uemiya et al., 1991]. 

C. Reactors with Monolithic Palladium-Based Membranes... 

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. 

As a main scope, the present chapter will give an overview on the general classification of the membranes, paying particular attention to the palladium-based membranes and their applications, pointing out the most important benefits and the drawbacks due to their use. Finally, the application of palladium-based membranes in the area of the membrane reactors will be illustrated and such reaction processes in the issue of hydrogen production will be discussed. 

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. 

Palladium-based composite membranes for hydrogen separation in membrane reactors... 

The design of the Pd-membrane reactor was based on the chip design of reactor [R 10]. The membrane is a composite of three layers, silicon nitride, silicon oxide and palladium. The first two layers are perforated and function as structural support for the latter. They serve also for electrical insulation of the Pd film from the integrated temperature-sensing and heater element. The latter is needed to set the temperature as one parameter that determines the hydrogen flow. 

---