(78a) Optimum Design of Blue Hydrogen Production System Using Steam Methane Reforming with CO2 Capture and Storage (CCS) Process Utilizing Liquefied Natural Gas Cold Energy

Hydrogen is an important alternative energy fuel source to help reduce emissions in accordance with the Paris Agreement. It is mainly produced from natural gas by the steam methane reforming (SMR) process in which carbon dioxide is generated as a by-product. This carbon dioxide should be captured and liquefied after which it can be stored. In the first part of our study, an optimized process for hydrogen production is proposed. This process involves capturing carbon dioxide from the tail-gas and SMR product streams using the amine absorption process. The captured CO₂ is subjected to a three-stage compression-cooling cycle. Liquefied natural gas (LNG), which is already used as both reactant and fuel for the SMR process, is further utilized to liquefy the CO₂ in a cryogenic heat exchanger. In the second part of this study, four types of heat exchangers are evaluated for this task: Double pipe, Shell and Tube, Plate, and Plate-Fin. For each exchanger type, a full design is performed considering rigorous modeling of thermal and hydraulic performance, conductive distribution in axial direction, flow instability, and thermal characteristics of metals. An economic evaluation for each design is performed for the equipment, installation, maintenance, and utility costs and the results are compared. Aspen HYSYS V12 is used for the process simulations and Aspen Exchanger Design and Rating (EDR) is used for rigorous heat exchanger design and modeling.