Abstract
The liquefied natural gas (LNG) industry continues to play an important role in the global energy market. As the liquefaction process is the critical segment of the LNG value chain, this review describes and compares five of the most significant recent and emerging liquefaction technologies: propane precooled mixed refrigerant, Ap-X (R), dual mixed refrigerant, mixed fluid cascade, and optimized cascade. In addition, since the liquefaction train is the core of the liquefaction process, three key components of the liquefaction train are analyzed: refrigerant compressors, compressor drivers and heat exchangers. The size of liquefaction trains has grown steadily as developers seek to realize economy of scale in order to achieve lower unit costs. Technology selection of process and equipment should be based on technical and economic considerations including experience, reliability, process efficiency, site conditions, and environmental impacts.