Optimization and energy consumption analysis of BOG treatment processes in LNG terminal

To further optimize the BOG treatment process in LNG terminals and reduce energy consumption of the entire LNG terminal, a LNG terminals with LNG output capacity of 200 t/h and BOG evaporation of 3.04 t/h is taken as an example to analyze power consumptions of two classical BOG treatment processes, namely re-condensation process and direct compression process. The results show that BOG compressors and high-pressure LNG pumps contribute dominant proportions in energy consumption. ASPEN-HYSYS simulation software is used to optimize existing processes. Specifically, LNG is further pressurized to a level higher than outlet pressure, and the gasification and expansion of the high-pressure outlet natural gas are used to compress BOG and pressurize LNG. The improved BOG direct compression process and re-condensation process can reduce energy consumption by 1 616.27 kW and 1 270.64 kW, respectively.