Air Liquide Italy supplied 500,000 m3 of Nitrogen for a 500-kilometer underwater pipeline linking Libya and Sicily.

The pipeline, also known as the Greenstream project, will transfer natural gas between the Libyan city of Mellitah and the petrochemical plant in Gela, Sicily. This will enable Libya to export a large portion of its natural gas resources to Europe.

The Pipeline consists of more then 500km of 32-inch underwater gas line, constructed by the SAIPEM company to transport this gas across the Mediterranean, at depths exceeding 1000 metres in certain places.

Air Liquide Italy’s role in the project was to supply approximately 500,000 m3 to the Weatherford company. Weatherford specialise in services for the petroleum industry and was contracted by SAIPEM to meet a number of industrial needs at the Gela site.

The large quantities of nitrogen are used in purging and inerting operations, which are conducted to ensure safety before a gas line can be commissioned. To prevent explosions, it is essential that all oxygen be completely removed from within the pipeline before any natural gas is injected.

Teams from Air Liquide Italy mobilised their resources to produce liquid nitrogen at the Priolo site in Sicily. A continuous supply of liquid nitrogen was then transported to the Gela site approximately 110km away in cryogenic tank trucks at a controlled temperature of –196 oC. The next step in the process was to vaporise the liquid nitrogen using heat exchangers installed at the SAIPEM site, then inject it into the pipeline.

Francois Darchis, a member of the Executive Committee of Air Liquide said that they were happy to be part of the team, “ We are very pleased to have been able to address the special needs of this project, both in terms of high volumes and rapid response. This work helped contribute to the optimal safety conditions that were required before the pipeline could be put into operation. Our teams demonstrated that they can react quickly, accompanying clients throughout a project, even when exceptional operations are involved.”