钯银合金膜反应器中二甲醚水蒸汽重整体系的透氢性能研究

二甲醚(DME)由于其清洁环保特性成为燃料电池电动汽车的理想氢源之一。在200~300℃温度范围,1.0×105~4.0×105Pa的压力范围内,Pd-Ag-Au-Ni合金膜对H2与Ar和N2的分离系数接近无穷大,同时,膜具有较好的透氢稳定性。通过实验研究了膜反应器中Ar、N2、CO、CO2、H2O和DME等气体存在时对钯银合金膜透氢性能的影响。实验结果表明,Ar、N2、DME基本对透氢性能无影响,CO2、CO、H2O存在时,会影响氢气的渗透性。三者当中,CO2的影响最小,混合气中H2O比CO对透氢性能的影响大,这是由于H2O在钯膜表面有更大的竞争吸附作用。本研究结果为更详细地研究二甲醚水蒸气重整制氢过程提供了重要参考依据。

Hydrogen Permeation Performance of a Pd-Ag Membrane Reactor in Dimethyl Ether Steam Reforming System

The dimethyl ether steam reforming (DME SR) system, which is used to produce the hydrogen-rich gas for fuel cell feeding application, can be a promising fuel provider due to its property of being friendly to environment. The Pd-Ag-Au-Ni membrane is usually used in the DME SR system to separate and purify the hydrogen produced from DME SR. At the temperature range of 200～300℃ and pressure range of 1.0×10~5～4.0×10~5 Pa, the H_2 permeation performances of the palladium-silver alloy membrane for gas mixture of hydrogen with Ar_2, N_2, CO, CO_2,.H_2O and DME were investigated, respectively. The results show that the separation factors of palladium-silver alloy membrane for gas mixture of H_2/N_2 and H_2/Ar_2 are nearly infinity, and the membrane shows good permeation stability. The co-existed Ar_2, N_2 and DME have negligible effect on hydrogen permeation through the investigated membrane, while the co-existed CO, CO_2 and.H_2O have negative influence of inhibiting the H_2 permeation through the membrane, and between them, the co-existed CO has the smallest inhibitive effect on H_2 permeation through the membrane, and the co-existed H_2O has a larger inhibitive effect than CO; it is due to the competitive adsorption of H_2O on the palladium metallic surface is stronger than hydrogen. The obtained H_2 permeation performance data of the Pd-Ag-Au-Ni membrane could provide fundamental data for the design of DME SR system.