Advanced natural gas liquefaction and regasification processes: Liquefied natural gas supply chain with cryogenic carbon capture and storage

Abstract

Natural gas combined cycle power plants generate substantial amounts of CO2. Also, since natural gas is produced in limited sites, the liquefied natural gas (LNG) supply chain consumes considerable energy in transporting natural gas overwide. Herein, advanced natural gas liquefaction and regasification processes using an LNG supply chain with cryogenic CO2 capture and storage (CCS) are proposed using Aspen Plus® V11. This solves three significant problems associated with conventional LNG supply chains. First, through the utilization of LNG cold energy, the cryogenic CCS process reduces the efficiency penalty of power generation from 14.34 to 4.45%. Second, solid CO2 from cryogenic CCS is used as an additional cold source in the natural gas liquefaction process by conveying it to the liquefaction site via the returning LNG ship. As a result, the power consumption in the refrigerant cycle is reduced by up to 67.17% than single mixed refrigerant (SMR) process. Finally, the LNG supply chain with cryogenic CCS minimizes the sustained energy waste between the natural gas liquefaction and regasification stages owing to the geographical separation. LNG cold energy from the regasification stage is utilized in the form of solid CO2 in the CCS and liquefaction stages. Consequently, the exergy efficiency in the overall LNG supply chain increases from 18.18 to 46.39%. The findings of this study can potentially provide environmentally friendly design guidelines for various LNG processes that use LNG cold energy in CCS and natural gas liquefaction.