Monday, June 23, 2014

Analysis of H2S Tolerance of Pd-Cu Alloy Hydrogen Separation Membranes

CATEGORY: HYDROGEN
Chinese Journal of Chemical Engineering, Volume 22, Issue 5, May 2014, Pages 503–508
Analysis of H2S Tolerance of Pd-Cu Alloy Hydrogen Separation Membranes
Huiyuan GAO, Ling WANG
College of Chemical Engineering, Hebei United University, Tangshan 063009, China
Abstract
The presence of relatively small amounts of H2S in H2-rich feed adversely affects the Pd-Cu membrane permeation performance due to the sulfidization of the membrane surface. Authors present a theoretical model designed to predict the S-tolerant performance of the Pd-Cu membranes in presence of H2S under the industrial water-gas-shift (WGS) reaction conditions.
They incorporated the concepts of surface coverage and competitive adsorption thermodynamics of H2S and H2 on Pd-Cu surface in the model. They observed that the surface sulfidization of the Pd-Cu membranes mainly depended on the pressure ratio of H2S to H2, temperature and S-adsorbed surface coverage. In other words, the occurrence of sulfidization on the surface was not directly related with the bulk compositions and structures of Pd-Cu alloy membranes because of the surface segregation phenomena. The resulting equilibrium equations for the H2S adsorption/sulphidization reactions were solved to calculate the pressure ratio of H2S to H2 over a wide range of temperatures.The model can be used to guide the development of S-resistant Pd alloy membrane materials for hydrogen separation.
Full Text Source (Subscription or Fee): http://www.sciencedirect.com/science/article/pii/S1004954114600690

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