The joint venture partners behind the $10bn Shah gas development in Abu Dhabi plan to make a final decision on the key sulphur transport element of the project in February, according to sources close to the scheme.

Abu Dhabi National Oil Company (Adnoc) and the US’ ConocoPhillips are considering two different ways of transferring 7 million tonnes a year (t/y) of sulphur between production and processing facilities at the southern Shah gas field and processing and distribution units at Habshan and Ruwais.

The two options under consideration are a technically complex pipeline which would transfer the sulphur as a liquid, and a railway which would transport the chemical in a granulated pellet form.

“They have told us that they will reach a final decision and let us know in February,” says the business development manager of one firm prequalified to bid on the pipeline deal.

The partners had originally planned to use a pipeline to transfer the sulphur when the project was first drawn up, but a lack of interest in the scheme when construction deals were tendered in June made them rethink their options.

Sulphur must be constantly heated to 120-140C in order to be transported as a liquid, and any flaws in the pipeline which allowed the sulphur to meet water would create the dangerous chemical sulphuric acid.

However, the rail scheme also has its drawbacks. Engineering executives consulted by MEED say the railway scheme will create more pollution and is less efficient than the pipeline, although the 275km link would be simpler to develop.

If Adnoc and Conoco choose to pursue the rail option, they will need to substantially alter the scope of the project. Under the current designs, the liquid sulphur is converted to granulated pellets at a handling and export terminal at Ruwais. Part of this terminal would have to be relocated to Shah in order to prepare the sulphur for rail transportation.