[1] The Grain LNG terminal is located on the site of the BP Kent Refinery which closed in 1982 and was subsequently demolished.
In 1980 British Gas constructed an LNG peak-shaving facility on the south west of the refinery site.
[2] The facility was used to support the NTS at times of high demand, and to ensure the security of gas supplies in SE England.
During periods of high demand liquefied gas was pumped from storage tanks and heated in vapourisers to a gaseous state for delivery into the NTS.
At times of low demand gas could be withdrawn from the NTS and liquefied by cryogenic cooling to minus 162 °C to replenish the storage tanks.
The original storage tanks were refurbished and new boil-off compression facility for ship offloading was installed.
The new facilities enabled the Grain terminal to become a base supply to the NTS, with the ability to deliver gas continuously when required.
The LNG was obtained on the competitive world market from a diversity of sources in North and West Africa, Russia, the Middle East and the Caribbean.
Each tank has a concrete mass of 72,000 tonnes and is supported on 1,560 piles, 600 mm in diameter and a depth of 24 metres.
The new plant brought the capability of the site to a throughput of 10.5 million tonnes of LNG (about 12% of UK gas demand).
[5] The 36-inch diameter 4.5 km nickel-steel pipeline has a flexible polyurethane (PUR) foam insulation in a high-density polyethylene (HDPE) casing, the line transfers LNG between the jetty and the storage sites.
[11] A ship reloading facility was added to the terminal in 2015[12] to enable shippers to take advantage of competitive world prices.
[1] Current (2016) users include BP, Centrica (British Gas Trading), Iberdrola (Spain), Sonatrach (Algeria), Engie (France), and Uniper (Germany).
There is a propane storage and blending unit to increase the calorific value of the gas entering the NTS if required.
Grain LNG is classified as an Upper-Tier site under The Control of Major Accident Hazards (COMAH) Regulations 2015.