(677b) Feasibility Study of Pressure Swing Adsorption (PSA) Processes for CO2 Capture and H2 Purification in Blue Hydrogen Processes and Hydrogen Deblending in the Gas Network

A methane reforming-based hydrogen has a distinctive advantage over green hydrogen in that it is dispatchable when needed under any climate conditions. Accordingly, the conventional hydrogen is expected to play a key role in the future hydrogen supply chain, even after green hydrogen processes are widely deployed. However, the fossil fuel-based hydrogen production process must be decarbonised so that it can also contribute to achieving the net zero emission target.

An adsorption process has been actively studied for CO₂ capture mainly from two locations of the H₂ production process: One is the synthesis gas generated by reforming of methane or light hydrocarbon or gasification of biomass, coals or heavy hydrocarbons, and the other is the H₂ PSA tail gas of a hydrogen production process following. It is still uncertain which feed stream would be more advantageous for CO₂ capture. In this study, a feasibility study was carried out to answer this question [1].

The second part of this study is to redesign the H₂ purification PSA for producing a high-purity H₂ from the CO₂-depleted synthesis gas downstream of a CO₂ capture unit applied to the synthesis gas and to estimate the H₂ PSA performance [2].

It is imperative to find a way to supply both hydrogen and methane at the same time to meet the demands of household and industry for both fuel gases during the transition period. To this end, it is likely that hydrogen is blended with methane and the gas mixture is transported through the existing gas network. The gas mixture must be separated into each of two gases near the final stage of the gas distribution network. A PSA process designed for separation of hydrogen from methane was evaluated at various mixing ratios of the two gases.

1. Chen and Ahn, Feasiblity Study of Vacuum Pressure Swing Adsorption for CO₂ Capture from an SMR Hydrogen Plant: Comparison between Synthesis Gas Capture and Tail Gas Capture, Frontiers in Chemical Engineering 3, 742963, 2021.

2. Luberti et al., Design of a H₂ PSA for Cogeneration of Ultrapure Hydrogen and Power at an Advanced Integrated Gasification Combined Cycle with Pre-combustion Capture, Adsorption 20(2-3), 511-524, 2014.