Dynamic simulation and operation optimization of BOG compressors in LNG gasification plant

An algorithm was proposed to optimize the operation of BOG compression based on dynamic simulation of LNG tank. It adopted empirical boil off rate model to predict the BOG production, used MILP formula to distribute the BOG compressor load, and made safety analysis by using dynamic simulation software. Aspen Dynamics software with PR state equation was also adopted insteading of simplified dynamic model to improve the accuracy. By the dynamic simulation of LNG tank pressure, the undulating quantities within safe pressure ranges when the BOG compressors were operated normally have been achieved. This algorithm is better than the algorithm used in routine processes, and is safer and more energy-efficient.