ScholarWorks@Y-Scholar Hub

초록

This study presents two advanced steam methane reforming (SMR) plants for LNG to blue H2 production, incorporating an effective thermal integration strategy focused on cross-sectoral low-quality waste heat recovery (L-WHR). The analysis of the integrated plant performance is critical, as unit-process level intensification does not always guarantee overall plant gains. The proposed SMR configurations feature a power-generating LNG regasification process, advanced stripper-free (SF) or solvent-looping (SL) CO2 absorption processes, an H2 twelve-bed vacuum pressure swing adsorption process, and steam turbine system. Pinch analysis was conducted to design heat-exchanger networks that redistribute waste heat across sectors, eliminating external heating demands. Since the SF-incorporated SMR plant benefited from a lower regeneration temperature, it achieved higher ratio of useful energy output to total feed energy input (plant efficiency: 71.4 %) and net electricity generation (2.239 kJ/molH2). In contrast, a higher regeneration temperature and semi-lean solvent cycle of the SL-incorporated case limited L-WHR and increased electricity consumption. Therefore, this configuration demonstrated 70.9 % plant efficiency and only 0.015 kJ/molH2 net electricity generation. However, compared to a conventional SMR plant, CO2 intensity was reduced from 10.36 to below 4.00 kgCO2/kgH2 in both cases. Under a carbon tax of $33.03/tonCO2andanH2priceof$1.50/kgH2, net profits reached $787.71and$753.02 per ton H2 for the proposed SF-and SL-incorporated cases, respectively, about 1.5 times higher than the conventional case ($510.59/tonH2). This outperformance from enhanced H2 recovery, carbon tax savings, and integrated L-WHR highlights a viable, near-term pathway for highly efficient low-carbon H2 production, accelerating the H2 economy.