Each larger than the Royal Albert Hall – and with four times the capacity of each of the original LNG storage tanks at Grain – they have quadrupled the LNG handling capacity at the site. Each tank has a diameter of 92.4m and is 50m high. They are constructed on piles 600mm in diameter, with 1,560 piles per tank to a depth of 24m to support a concrete mass of 72,000 tonnes per tank. A special technique developed by main contractor CB&I used fans to lift the prefabricated 9% nickel steel roofs into place on the tanks. During this significant construction activity, National Grid and CB&I have celebrated two major safety milestones, each of one million man-hours worked with no lost-time injury.
Committed to investing in the future
Further construction work is underway at Grain LNG to provide an additional five million tonnes of capacity in winter 2010/11. This includes the construction of a second state-of-the-art jetty, capable of taking the world’s largest LNG ships, Q-max vessels with a capacity of up to 265,000 cubic metres. An additional storage tank and associated plant are also being constructed and the work will take the terminal capacity to 20% of the UK’s current gas demand.
Meeting UK gas specification
The UK has traditionally used gas from the North Sea and our gas equipment is designed to use gas of this specification. LNG is imported from a variety of countries around the world and to ensure it meets the UK specification nitrogen may need to be added. At Grain this is supplied by Air Products at up to 65 tonnes per hour and to ensure continuity of supply a 4,000 tonnes liquid nitrogen storage vessel has been constructed.
Powering the future
A new 132kV to 11kV substation has been constructed to meet the power requirements of Grain LNG. The two power transformers are capable of supplying 2 x 120MW and are supplied from National Grid’s 400kV substation at Grain power station.
Environmental initiative
Grain LNG needs warm water to return the LNG back to a gas and currently the heat required is provided by burning gas. By working closely with E.ON surplus heat is to be provided from their new gas-fired power station to vapourise the LNG. By using the heated water generated by the power station, Grain LNG can save enough fuel to heat 240,000 homes for a year and reduce carbon emissions by up to 350,000 tonnes every year. It also means that less heat is dispersed by the power station.