Research progress on the BOG recovery technologies used at LNG stations

Boil-off gas (BOG) is one of the main factors influencing the safety, environmental protection and economic operation of LNG station, and its recovery is a difficulty which needs solving urgently. In this paper, domestic and foreign researches related to BOG recovery technologies of LNG station were investigated. Then, based on the factors influencing the generation of BOG, the research progresses, advantages and disadvantages of eight main BOG recovery technologies were discussed, including pulse tube refrigerator, nitrogen expansion refrigeration recovery, liquid nitrogen recovery, jet liquefaction recovery, mixed refrigerant liquefaction recovery, direct compression process, reliquefaction process and combined process of direct compression and reliquefaction, and the corresponding optimization methods were proposed. Finally, combined with the actual needs of LNG stations, the economic and effective BOG recovery schemes for different types of LNG stations were prepared while satisfying the premise of the safe operation and environmental protection of LNG stations. What's more, the future development of BOG recovery technologies was prospected.