| dc.description.abstract | Under the global pursuit of the goal of net zero carbon emissions, searching for new energy sources has become an inevitable issue. The energy importance of hydrogen is current research topic, but if hydrogen is to be used in fuel cells or other purposes, extremely high purity is required.
In this study, the simulation of pressure swing adsorption (PSA) was used to purify hydrogen from steam methane reforming gas (SMR) , and activated carbon and zeolite 5A were used as adsorbents.The gas composition of methane steam reforming gas is 75.26% hydrogen, 22.68% carbon dioxide and 2.06% carbon monoxide. Among adsorbents, zeolite 5A has a higher selectivity for carbon dioxide than zeolite 13X, and the literature survey shows activated carbon-zeolite layered adsorbent in adsorption bed is usually used. Therefore, this study uses activated carbon-zeolite 5A layered bed to investigate the hydrogen purity and recovery obtained by PSA.
In order to obtain high-purity hydrogen, this study uses design of experiments (DOE) to find the optimal operating conditions in line with the PSA processes, and conducts a two-level full factorial design. The regression model obtained through calculation can be obtained. The purity of hydrogen by a three-bed nine-step PSA is 99.12% with a recovery of 63.08%, and the purity of hydrogen by a three-bed fifteen-step PSA is 99.999% with a recovery of 44.19%.
As a result of the three-bed nine-step process, although the hydrogen purity reaches only 99%, it can only be applied to relatively basic chemical reactions such as petrochemical industry, ammonia production, methanol production, etc., but the recovery is better than the three-bed fifteen-step procedure.
Although the hydrogen recovery of the three-bed fifteen-step procedure is only 44.1981%, the hydrogen purity is significantly improved compared to the three-bed nine-step process. Therefore, this process can be applied to more sophisticated industries, such as fuel cells and semiconductor industries. | en_US |