The presence of a limited amount of H2S in H2-rich feed adversely affects the Pd-Cu membrane permeation performance due to the sulphidization of the membrane surface. A theoretical model was proposed to predict the S-...The presence of a limited amount of H2S in H2-rich feed adversely affects the Pd-Cu membrane permeation performance due to the sulphidization of the membrane surface. A theoretical model was proposed to predict the S-tolerant performance of the Pd-Cu membranes in presence of H2S under the industrial water-gas-shift(WGS) reaction conditions. The ideas of surface coverage and competitive adsorption thermodynamics of H2S and H2 on Pd-Cu surface were introduced in the model. The surface sulphidization of the Pd-Cu membranes mainly depended on the pressure ratio of H2S to H2, temperature and S-adsorbed surface coverage, i.e., the occurrence of sulphidization on the surface was not directly related with the bulk compositions and structures [body centered cubic and face centered cubic(bcc or fcc)] 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. A validation of the model was performed through a comparison between lots of literature data and the model calculations over a rather broad range of operating conditions. An extremely good agreement was obtained in the different cases, and thus, the model can serve to guide the development of S-resistant Pd alloy membrane materials for hydrogen separation.展开更多
Ti-Ni porous alloy was made from titanium and nickel powder mixture in equiatomic composition by combustion synthesis technique (self-propagation high temperature synthesis). The result analyzed by SEM and XRD shows t...Ti-Ni porous alloy was made from titanium and nickel powder mixture in equiatomic composition by combustion synthesis technique (self-propagation high temperature synthesis). The result analyzed by SEM and XRD shows that the alloy possesses high porosity (50%～70%), and mainly consists of TiNi phase as well as rare Ti_2Ni and TiNi_3 transition phase. Then it was activated, cracked and used as sorbent for hydrogen isotope separation. Through experiment investigation, it was discovered that the alloy is able to absorb hydrogen in very large quantities in the lattice thereof, but deuterium only very slightly or not at all, at temperatures up to 623 K, especially at temperatures from about 323 to 423 K. According to this characteristic, the Ti-Ni porous alloys may replace noble metal palladium(Pd) as used for hydrogen isotope separation and purification. Study illustrated that the technology would have a promising engineering application, such as being used for reprocessing Tokamak exhaust gases and producing high purity deuterium.展开更多
It describes the purification of hydrogen isotopes, separation with the preparation of palladium-based membrane's technology, types, application, advantages and disadvantages of palladium in this article. Due to e...It describes the purification of hydrogen isotopes, separation with the preparation of palladium-based membrane's technology, types, application, advantages and disadvantages of palladium in this article. Due to excellent comprehensive properties palladium composite membrane will become the future direction of development. At the same time it will develop preparation methods of the membrane support body with high mechanical strength and heat resistance and low-cost and palladium-based membrane. Also it will explore high service life and high transmittance of novel composite membrane.展开更多
基金Supported by the National Natural Science Foundation of China(50972038)the National Natural Science Foundation of Hebei Province(B2009000739,B2014209258)Science and Technology Support Program of Hebei Province(09215142D)
文摘The presence of a limited amount of H2S in H2-rich feed adversely affects the Pd-Cu membrane permeation performance due to the sulphidization of the membrane surface. A theoretical model was proposed to predict the S-tolerant performance of the Pd-Cu membranes in presence of H2S under the industrial water-gas-shift(WGS) reaction conditions. The ideas of surface coverage and competitive adsorption thermodynamics of H2S and H2 on Pd-Cu surface were introduced in the model. The surface sulphidization of the Pd-Cu membranes mainly depended on the pressure ratio of H2S to H2, temperature and S-adsorbed surface coverage, i.e., the occurrence of sulphidization on the surface was not directly related with the bulk compositions and structures [body centered cubic and face centered cubic(bcc or fcc)] 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. A validation of the model was performed through a comparison between lots of literature data and the model calculations over a rather broad range of operating conditions. An extremely good agreement was obtained in the different cases, and thus, the model can serve to guide the development of S-resistant Pd alloy membrane materials for hydrogen separation.
文摘Ti-Ni porous alloy was made from titanium and nickel powder mixture in equiatomic composition by combustion synthesis technique (self-propagation high temperature synthesis). The result analyzed by SEM and XRD shows that the alloy possesses high porosity (50%～70%), and mainly consists of TiNi phase as well as rare Ti_2Ni and TiNi_3 transition phase. Then it was activated, cracked and used as sorbent for hydrogen isotope separation. Through experiment investigation, it was discovered that the alloy is able to absorb hydrogen in very large quantities in the lattice thereof, but deuterium only very slightly or not at all, at temperatures up to 623 K, especially at temperatures from about 323 to 423 K. According to this characteristic, the Ti-Ni porous alloys may replace noble metal palladium(Pd) as used for hydrogen isotope separation and purification. Study illustrated that the technology would have a promising engineering application, such as being used for reprocessing Tokamak exhaust gases and producing high purity deuterium.
文摘It describes the purification of hydrogen isotopes, separation with the preparation of palladium-based membrane's technology, types, application, advantages and disadvantages of palladium in this article. Due to excellent comprehensive properties palladium composite membrane will become the future direction of development. At the same time it will develop preparation methods of the membrane support body with high mechanical strength and heat resistance and low-cost and palladium-based membrane. Also it will explore high service life and high transmittance of novel composite membrane.
