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Keywords
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Hydrogen purification, Breakthrough curve, Adsorption isotherms
Adsorption kinetics, Activated carbon, Zeolite, Aspen adsorption
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Abstract
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Hydrogen production often yields impure streams containing N2, CO, CO2, CH4, and C2H6. This study investigates the adsorption performance of five industrial adsorbents—two activated carbons (AC1 and AC2) and three zeolites (Zeo1, Zeo2, and Zeo3)—for H2 purification. Volumetric methods were employed to examine adsorption isotherms for H2, N2, CO, CO2, CH4, and C2H6 at pressures up to 6 bar and temperatures of 283, 303, and 323 K. Diffusion time constants were obtained by fitting Kočiřík's equation to pressure-decay experimental data, enabling the calculation of mass transfer coefficients. Subsequently, the experimental data were applied to simulate adsorption and desorption breakthrough curves for two different layered-bed configurations under industrial-scale conditions using Aspen Adsorption software. The results showed that zeolites, with their ordered crystalline structures, were more effective for adsorbing polar gases like CO2 at low pressures, while activated carbons exhibited faster adsorption kinetics, owing to their broader pore size distribution. The simulation results revealed a significant difference in gas breakthrough times between the two layered-bed configurations, particularly for CO.
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