Integrated hydrogen liquefaction with autothermal reforming utilizing liquefied oxygen as a pre-coolant

초록

Among natural gas-based hydrogen production methods, autothermal reforming (ATR) has a high efficiency for carbon capture and storage integration due to the high CO2 levels at the reactor outlet. This study proposes an integrated system (ATR/HLU–LOX) that utilizes liquefied oxygen (LOX) in the precooling stage of the hydrogen liquefaction unit (HLU) to reduce liquefaction energy costs and CO2 intensity. This conducted an enviro-techno-economic analysis for large-scale hydrogen production (100 tonnes/day) suitable for natural gas valorization and hydrogen storage. Additionally, this study evaluated the performance of a CCS-based ATR system (ATR–CCS/HLU–LOX) and compared it to LOX-free liquefaction unit (ATR/HLU and ATR-CCS/HLU). For further comparison, grey and blue steam methane reforming (SMR) for hydrogen generation was also investigated (i.e., SMR/HLU and SMR–CCS/HLU systems). The main findings of this study depicted that ATR–CCS/HLU–LOX reduced specific energy consumption by 6.6% and lowered the levelized cost of hydrogen and global warming impact by 1.3 and 11.0%, respectively, compared to SMR–CCS/HLU. This achievement can encourage adopting ATR for various applications (e.g., flare gas treatment, blue hydrogen generation, and subsurface NG valorization) instead of high CO2 emitting SMR. © 2024

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