Mossmorran

The Mossmorran NGL fractional plant is part of the North Sea Brent oil and gas field system located on the outskirts of Cowdenbeath, Fife.

After gas is separated from oil on the rigs offshore, the gas is then pumped ashore in the FLAGS pipeline to a terminal at St. Fergus operated by Shell. Here the methane is separated from the rest of the gas product. The methane is then sent to a neighbouring national grid plant, leaving the remaining natural gas fluid to be piped south to the Mossmorran site in Fife. At the St. Fergus Gas Plant natural gas fluid is separated by distilation (in a number of columns) into ethane, propane, butane and natural gasoline. The ethane is then piped to an adjacnt ethylene plant operated by Exxon Mobile for further processing and cracking. The propane and butane is chilled, liquefied and stored on site, the gasoline is also stored on site. These liquids are then transported via pipeline to the marine terminal at Braefoot Bay on the Firth of Forth for loading into tankers.

The plant originally operated using two identical process modules (each with three columns) with a capacity of approximately 10,000 tonnes per day. This was later increased to 15,000 tonnes per day by the addition of a third process module and a few other up grades in 1992 at a cost of roughly £100 million. As well as the Brent fields the plants at St. Fergus and Mossmorran also process gas from the recently installed Goldeneye platform.

The flare from the Mossmorran site is clearly visible, day and night, from any elevated point in the city of Edinburgh.