Regasification process
At the Terminal, Liquid Natural Gas is unloaded from LNG vessels and stored in insulated tanks at atmospheric pressure and a temperature of about minus 162°C.
The LNG is warmed to a point where it reverts to its gaseous state. The heat to regasify the LNG is provided both by sea water, at its ambient temperature, and from turbine flue gases, thanks to an energy recovery system.
After the regasification process, the gas is sent through a pipeline to the national gas transportation network.
The Adriatic LNG Terminal uses the following equipment to regasify LNG:
- a) 4 Open Rack Vaporizers;
b) 1 Heat Recovery Vaporizer
Open Rack Vaporizers
Open Rack Vaporizers consist of vertical aluminum tubes arranged in racks. LNG flows up the inside of the tubes warming up and boiling off as gas. Sea water pours down the outside of the vaporizer tubes providing the heat to regasify the LNG.
Heat Recovery Vaporizer
The Heat recovery vaporizer utilezes heat from the power generation turbines on the Terminal that would otherwise be lost. This system therefore improves the overall energy efficiency of the regasification process.
The Heat Recovery Vaporizer utilizes a heat exchange liquid (a mixture of water and glycol) that flows in a closed loop circuit to capture heat from the hot exhaust gases of the power generation turbines.
The heat exchange fluid flows through a matrix of small diameter tubes in the exhaust flues of the turbines absorbing heat from the exhaust gases.
The hot fluid then flows to the Vaporizer. Inside the Vaporizer, the LNG flows upward through vertical tubes, warming and regasifying as it rises, and the heating fluid flows down around the outside of the tubes. Gas exits the top of the Vaporizer through a pipeline while the cooled heating medium returns to the exhaust flues to be re-heated.
