Dynamic Simulation Study for Boil-off Gas Minimization at Liquefied Natural Gas Exporting Terminals.

The boil-off gas (BOG) generation at LNG (liquefied natural gas) exporting terminals is significant and should be minimized and/or recycled efficiently and effectively. In this work, the study of BOG generation, minimization, and recovery has been performed for a typical LNG plant with C3MR (propane precooled mixed refrigerant) process, storage facility, loading facility, and LNG ship with four moss-type spherical tanks. Plant-wide dynamic simulations are employed to quantify dynamic BOG generations during loading and holding mode, under various LNG temperatures at LNG exporting terminals. On the basis of multiple case studies, optimum LNG temperatures under different LNG subcooling and BOG recovery strategies have been identified for the sake of total energy consumptions. This study provides valuable information about the effect of LNG subcooling temperature on BOG generation, which would help in operating LNG plants at optimum conditions and economically minimize BOG generation and recovering BOG at LNG exporting terminals. Conceivably, the resultant benefits are not only for the environmental sustainability (reduce emissions), but also for the LNG industry sustainability (save raw materials/energy and increase productivity). [ABSTRACT FROM AUTHOR]