암모니아 분해 기반 수소 정제를 위한 산화물 및 Pd 기반 중공사막 분리막의 성능 평가

초록

In this study, hydrogen separation membranes were fabricated by depositing γ-Al2O3, SiO2 oxide layers, and Pd metal films onto hollow fiber supports, and their permeation performance was compared under gas mixtures (H2, N2, NH3) generated from ammonia decomposition. scanning electron microscope and atomic force microscope analyses confirmed that oxide coatings significantly improved surface roughness, thereby suppressing defects during Pd electroless plating. Gas permeation test were carried out at 450°C and 0.5~2.0 barg. The oxide-based membranes, governed by pore diffusion mechanisms, exhibited a maximum hydrogen purity of 82%, whereas the metal-based membranes achieved hydrogen purity above 97% with a hydrogen flux of 15 mL/min and an H2/NH3 separation factor exceeding 1900 at 2 barg, demonstrating far superior performance. In conclusion, while oxide membranes showed limited separation ability as stand-alone layers, they proved effective as pretreatment and interlayers for Pd deposition. The Pd hollow fiber membrane ultimately exhibited outstanding hydrogen flux, purity, and selectivity, verifying its suitability as the most effective option for high-temperature hydrogen purification.

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