Hydrogen capture using zeolite 3A for pipeline gas deblending

Less than 20% of hydrogen gas can be co-transported with natural gas (NG) and distributed to end-users using existing gas pipelines. However, most industrial gas turbines can only tolerate up to 1% by volume of hydrogen in natural gas. A separation process is needed to selectively capture the minor component such as hydrogen. Herein, we report the design of a deblending process to meet the requirements of these specific industries. We demonstrated that zeolite 3A which is believed to be a trapdoor zeolite has a selectivity towards hydrogen molecules based on the laboratory experiment results. A multiple-bed pressure swing adsorption (PSA) using zeolite 3A was subsequently modelled for removing hydrogen at various concentrations from the blended gas. The results indicate that high pressure and high purity methane (>99%) can be obtained by the 3A PSA, making products suitable for gas turbines. When a methane PSA with activated carbon (AC) adsorbents is used for comparison, the process needs to do separation work towards the major component methane and an overwhelming pump work is required to repressurize the desorbed methane gas. Therefore, a hydrogen capture PSA process with zeolite 3A stands out in terms of product purity, recovery and energy consumption, for low concentration H₂ deblending from NG. © 2023 The Author(s)