Editor’s Note: Patrice Bardon, “Optimize LNG Liquefaction Operations through Proper Refrigeration Compressor Driver Selection”, 1427-1440, Proceedings of 23th World Energy Congress 2016 Istanbul – Research Papers, Ed.: Prof. A. D. Alkan, WEC Turkish National Comm., Vol.1, pp. 1427-1440, ISBN: 978-605-89548-9-2, 09-13.10.2016, Istanbul.
Natural gas liquefaction is an energy-intensive process. As a result, there is significant opportunity for operators to benefit by selecting the appropriate equipment for their specific LNG application. First, and perhaps most importantly, cleaner LNG solutions minimize greenhouse gas emissions. This is an important consideration, as we expect excessive emissions will eventually incur financial penalties. Secondly, reducing power consumption during the liquefaction process can be a source of substantial financial return.
The liquefaction island of a plant is simply a large refrigerator that consumes abundant energy to bring natural gas to approximately -163°C. Liquefaction can occur through various processes, and although not all offer the same efficiency, each has its own advantages that make it more or less suitable depending on project objectives. The choice of what driver configuration to use for liquefaction has lasting effects throughout the life of an LNG facility. Because of this, an adequate amount of time and effort should be put into evaluating options to ensure the optimal selection is made. This paper reviews equipment configurations that can be used to drive main refrigeration compressors for given liquefaction processes and discusses the relative benefits of each. It focuses on the power consumption of the main refrigeration island, and compares 10 main driver solutions. It also provides recommendations from an OEM perspective.
The driver solutions discussed in this paper include designs that are currently being used in liquefaction facilities throughout the world, as well as ones that have not yet been widely implemented. Depending on the requirements of an operation, other configurations not included in this paper may warrant consideration.