Abstract
The pressure in liquefied natural gas (LNG) storage tank continues to increase due to the heat transfer from ambient air to low temperature LNG, which raises safety concerns. Accordingly, there is increasing interest to explore the technical approaches capable of recovering Boil-Off Gas (BOG) and even eliminating the ventilation of LNG storage tank. This research numerically analyzed the greenhouse gas emissions of the re-liquefaction of BOG using the following four approaches: 1) a Claude cycle driven by electrical motor with the electricity produced by burning coal; 2) a Claude cycle driven by a gas turbine fuelled by BOG released; 3) a Claude cycle driven by a SI engine fuelled by gasoline; 4) burning nature gas directly released by BOG. The impact of heat transfer coefficient, LNG tank configuration, size, and percentage of LNG stored in tank on the rate of BOG and energy needed for the re-liquefaction of methane vapor were investigated. The greenhouse gas emissions (GGE) was examined and compared. The data presented in this paper provide guideline for the management of pressure development in LNG storage tank.
Highlights
With the continuous development of human economy and increasing of the energy consumption, the “global warming”, “ecosystem degradation” and other problems caused by the aggravate emissions of the greenhouseHow to cite this paper: Sun, G., Liu, S.C. and Li, X.Q. (2015) An Analysis of the Greenhouse Gas Emissions by the Re-Liquefaction of Boil-Off Gas of Liquefied Natural Gas (LNG) Storage Tank
The greenhouse gas emissions (GGE) from high to low is as follows: igniting the discharge of gaseous natural gas (NG), the Claude cycle driven by the Internal combustion engine, the Claude cycle driven by the electricity power and the Claude cycle driven by the gas turbine
The amount by using the re-liquefaction systems is for most 46% of the amount of greenhouse gas of igniting the directly discharge of gaseous NG, the least only 11.5%
Summary
With the continuous development of human economy and increasing of the energy consumption, the “global warming”, “ecosystem degradation” and other problems caused by the aggravate emissions of the greenhouse. Hoseyn Sayyaadi [13] [14] researched that onboard boil-off gas (BOG) re-liquefaction system as a cryogenic refrigeration cycle is utilized in order to re-liquefy the BOG and returns it to the cargo tanks instead of burning it. He performed the optimization in order to maximize the exergetic efficiency of plant and minimize the unit cost of the system product (refrigeration effect), simultaneously. In order to find the optimization cycle for BOG re-liquefaction, it is mainly analyzed about three different power input (electricity, gas turbine and internal combustion engine) for Claude Cycle to liquefying natural gas. The greenhouse gas emission through this method will be calculate and elaborate
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
