A review of liquefied natural gas refueling station designs

The majority of operational liquefied natural gas (LNG) refueling stations in the world have no boil-off gas (BOG) management and rely on regular LNG delivery to condense the BOG. To reduce the pressure of LNG tanks onboard vehicles prior to filling, the BOG is vented to the atmosphere, is collapsed in the tank, or is returned to the refueling station. In this study, different onboard LNG tank architectures are discussed, and the design strategies for LNG conditioning and BOG management technologies employed in LNG refueling stations are analyzed. The critical analysis of different designs of LNG refueling stations indicates that 44% of designs have no BOG management, 28% of designs rely on liquid nitrogen condenser or a liquefier to condense the BOG, and 28% of designs compress the BOG to produce compressed natural gas. Our research shows that in China and the U.S., where stations with BOG management are rare, the number of LNG refueling stations has increased by 32 and 3 times, respectively, between 2010 and 2015. This study highlights the fact that as heavy fuel oil and diesel are replaced by LNG, it is critical to pay proper attention to the design of the LNG supply chain and LNG refueling stations to minimize or eliminate BOG venting and reduce greenhouse gas emissions.