Proton-conducting ceramic membrane

Proton-conducting ceramic membranes have been studied as SOFC electrolytes for intermediate temperature, around 800°C, and can also be used as electrolytes in steam electrolysis. The families of SrCeOj and BaCeOj with dopants such as Y, Yb, and Nd on the Ce site show good selectivity for proton transport. The advantage of... 

Evaluate proton-conducting ceramic membranes for use in electrolyzers. 

General Properties of Perovskite-structured Proton-conducting Ceramic Membranes 51... 

General Properties of Perovskite-strucUired Proton-conducting Ceramic Membranes 57... 

As discussed in the previous section, one effective way to improve the H2 permeability of SrCe03-based proton-conducting ceramic membranes is to improve their electronic conductivity. Different ahovalent dopants have been studied for their effect on the electronic conductivity. Qi and Lin [66] found that the electronic conductivity is inversely related to the ionization potentials of 6 + and dopants. Table 2.3 lists experimentally determined electronic conductivities of SrCe03-based materials in pure O2 with the ionization potentials [67] of their dopant ions. 

Figure 2.9 Charge carrier concentration profiies inside proton-conducting ceramic membranes.

As discussed elsewhere in this text, there are two types of dense, hydrogen-permeable metal membranes to consider from the perspective of module scale-up and design thin metal foils and permselective metal layers formed on a porous support. Another class of hydrogen-permeable inorganic membranes - dense proton-conducting ceramic membranes - are still under development and are addressed in Chapter 2. 

Kniep, J., Anderson, M., Lin, Y. S. (2011). Autothermal reforming of methane in a proton-conducting ceramic membrane reactor. Industrial Engineering Chemistry Research, 50, 12426-12432. 

The application of these proton conducting ceramic membranes for H2 separation requires that the H2 and CO2 mixture gas leaving the WGS reactor be heated up again to 700—900 °C for H2 separation. This requires extra equipment and energy, and increase the capital investment for the H2 production process. 

Cheng, S., Gupta, V.K., and Lin, Y.S. (2005) Synthesis and hydrogen permeation properties of asymmetric proton-conducting ceramic membranes. Solid State Ionics, 176, 2653-2662. 

Wang, S., and Liu, S. (2014) External short circuit-assisted proton conducting ceramic membrane for H2 permeation. Ceram. Int, 40, 791-797. 

PROTON/HYDROGEN PERMEATION IN PROTON-CONDUCTING CERAMIC MEMBRANES... 

Figure 6.1 Formation of charged defects in proton-conducting ceramic membranes. Reproduced with permission from [13], Taylor Francis Ltd, http //www.tandf. co.uk/journals.

APPLICATIONS OF PROTON-CONDUCTING CERAMIC MEMBRANE REACTORS... 

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