Accurately Measuring LNG Tanker Boil-Off Gas For Process Efficiency And Environmental Compliance

By Steven Craig, Engineer, Fluid Components International LLC

With the recent growth in demand and production of liquefied natural gas (LNG), there has been an increase in trade and the need to transport it globally via LNG tanker ships. This increase in LNG transport has driven the need for expansion of the tanker fleets with increased capacity, wherein the LNG ships are typically carrying up to 266,000 m³ around the world. The LNG tanker fleets are unique because LNG cargo generates waste gas, commonly known as boil-off gas (BOG). This waste gas can be used as fuel for the ships boilers and must be accounted for in order to comply with current marine propulsion regulations for energy efficiency. Accurate flow measurement of the BOG to the ships boilers is essential to tanker operators.