Sustainable LNG supply chain enabled by clean and cost-effective energy self-integration via cold storage and the Allam cycle

Enhancing the liquefied natural gas (LNG) supply chain as the main method of energy transport is essential to improving energy efficiency and decarbonization in order to achieve net-zero emission goals. This paper introduces a novel approach to achieving energy self-sufficiency and a sustainable LNG supply chain by integrating both liquefaction and regasification stages through cold energy storage, the Allam cycle, and carbon capture, despite geographical separation. The new LNG supply chain features high energy efficiency, cost-effectiveness, and near-zero emissions. The cold energy from LNG at the regasification site can be harnessed to reduce the amount of energy consumed for liquefaction and yield economically advantageous by-products—separated nitrogen and liquid oxygen. The liquid oxygen shipped to the liquefaction site serves as a cold energy carrier, enhancing the energy efficiency of the process. The oxygen, along with the LNG boil-off gas, powers the Allam cycle, ensuring power self-sufficiency for liquefaction with minimal emissions. This highly efficient and eco-friendly concept yielded exergy efficiencies of over 62 % for all components and promising economic returns, with a net present value of 1.33 billion USD, an internal rate of return of 67.31 %, and a potential annual carbon tax reduction of 11.23 million USD.