Kinetic separation of green hydrogen from natural gas grids by using vacuum pressure swing adsorption

Transitioning to renewable energy sources is crucial to mitigating climate change. In this scenario, green hydrogen (GH) is considered a promising energy carrier due to its high calorific value, versatility in applications, clean combustion, and potential for local generation in abundance. As interest in GH grows, developing its distribution chain becomes crucial in facilitating its widespread use. The co-transporting GH into existing natural gas grids (NGG) emerges as a viable alternative, eliminating the need for significant infrastructure investments. However, upon blending GH into the NGG, it becomes essential to de-blend and purify it to a high degree to enable, for instance, fuel cell applications (H2 > 99,97%). One problem concerning the separation and purification of GH from NGG relates to the H2 feed concentration (< 20%), which differs significantly from conventional H2 purification processes (> 70%). Moreover, the high CH4 concentration and its relatively weak adsorption affinity on commonly used adsorbents further complicate achieving high-purity H2 and high recovery rates through conventional approaches. In this work, we report a novel conceptual vacuum pressure swing adsorption (VPSA) process to separate H2 from CH4 by exploiting the kinetic selectivity of H2 over CH4 on CMS-3K-172.

Kinetic separation of green hydrogen from natural gas grids by using vacuum pressure swing adsorption Artigo de Conferência