High purity helium and hydrogen production from natural hydrogen reservoir and natural gas

Abstract

Gold hydrogen, formed by natural processes and found within the Earth’s crust, is frequently mixed with helium gases. Due to the significant economic value of both hydrogen and helium, the development of efficient recovery and separation technologies is critical. Currently, cryogenic distillation is the only commercially viable method for helium production, but it is highly energy intensive. While the emerging membrane technologies are capable of separating helium from nitrogen or methane, they are sometimes ineffective for the separation of hydrogen from helium due to similar molecular sizes. Hydrogen/helium separation is also challenging for pressure swing adsorption (PSA) technology as adsorbents with helium or hydrogen selectivity are scarce. In this study, we devised a novel PSA technology that employs the metal alloy LaNi₅ as an adsorbent to effectively separate hydrogen from helium, achieving an enriched helium purity of 99.82 % with a recovery rate of 95.78 % from a 5 % helium feed gas. Remarkably, the specific energy required for helium production from natural gas using the proposed PSA process is only about 2 % of that required by cryogenic distillation, making it particularly suitable for small to medium scale applications. Furthermore, we extended this method to a double-stage PSA system with LiLSX zeolite and metal alloy as adsorbents respectively, which shows great potential for hydrogen and helium recovery from natural gas. This innovative approach offers a more energy-efficient and cost-effective approach for the extraction and purification of these valuable resources.