釩合金穿透膜應用於氨分解氣體之氫氣純化技術

本研究主要了解釩合金穿透膜於氨分解氣體中純化氫氣之特性表現，以氫氣、氫氮混合氣（氫：氮=3:1）及氨混合氣（氫：氮=3:1+1%氨）於不同操作溫度下進行氫穿透實驗。在使用純氫氣的氫穿透實驗中，釩合金薄膜在400°C下表現出最高2.30×10^(-8) mol H_2×m-(1)×s(-1)×Pa^(-1/2)之氫氣穿透率，氫穿透率隨著操作溫度降低而逐漸下降，氫穿透率在利用氫氮混合氣及氨混合氣實驗中並無觀察到混合氣對薄膜的負面影響，其通入氣體流速測試中解釋了因混合氣所表現出的濃度極化現象。實驗以X射線光電子能譜儀（XPS）了解氨氣對不同表面保護層之影響，實驗結果中敘述了氨氣在不同表面保護層上之吸附行為，其氨氣對於具保護層之合金穿透膜並沒有毒化或損害的現象。在氨混合氣長時效之氫穿透實驗中，釩合金穿透膜表現出相當良好的耐久度。本研究顯示釩合金穿透膜在氨分解氣體中純化氫氣之應用具有高度的開發潛力。

關鍵字

氫氣；氨氣；釩；穿透膜； X射線光電子能譜儀

並列摘要

Hydrogen permeation measurements of Pd-25Ag-coated vanadium alloy were carried out at 200°C to 400°C under 0.1 MPa pure hydrogen, H_2:N_2=3:1 and H_2:N_2=3:1+1% NH_3 atmospheres. The highest hydrogen permeability of the V alloy membrane was 2.30×10^(-8) mol H_2×m(-1)×s(-1)×Pa(-1/2) at 400°C and decreased with temperature decreasing. Compare with the pure hydrogen atmosphere, the hydrogen permeabilities slightly decreased when the H_2:N_2=3:1 and H_2:N_2=3:1+1% NH_3 atmospheres were employed due to the lower H_2 partial pressure near the membrane surface. The phenomenon of concentration polarization was described in the feed flow rates test. The effects of nitrogen and ammonia on the different surface protection layers were studied on the basis of the surface composition by X-ray photoelectron spectroscopy (XPS). The N1s photoelectron peaks were found in the both Pd and Pd-25Ag samples after permeation test under H_2:N_2=3:1+1% NH_3 atmosphere at 300°C and 400°C. It demonstrated that ammonia adsorbed on the surface of the membranes, but not poisoned or damaged the surface. The V alloy membrane also had good durability at 300°C and 400°C by using ammonia-included atmosphere. The vanadium alloy membrane could be a potential candidate for hydrogen separation from ammonia decomposed gas.

並列關鍵字

vanadium (V) ； membrane ； permeation ； hydrogen ； ammonia ； XPS

國際替代計量

釩合金穿透膜應用於氨分解氣體之氫氣純化技術

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