(489b) Estimation of Boil-Off Gas from LNG Tankers and Storage Tanks

A simple calculation scheme is proposed for fast and efficient estimation of LNG (Liquified Natural Gas) losses from storage tanks and tankers. A numerical method is developed with respect to time and variable heat transfer rate to each component in the LNG. Both natural and forced Boil-Off Gas (BOG) are calculated versus time for each component. The excel program developed requires initial composition, volume, rate of heat transfer, temperature and pressure and it estimates volume of LNG losses, volume and composition as well as some physical properties such as density, vapor pressure, equilibrium ratios, and heat of vaporization for the LNG remaining in the tank versus time.