Saudi Petrochemical Company (Sadaf) is undergoing a major expansion with a second styrene monomer project currently under construction.

The company, which is an affiliate of Saudi Basic Industries Corporation (Sabic) will be an exhibitor at Saudi Build 2000.

The 500,000 tonnes per year (tpy) styrene plant will boost Sadaf's total styrene output to 950,000 tpy when it comes on stream shortly.

The new plant is a 50:50 joint venture between Sadaf and Petrokemya, while the first styrene plant is a 50:50 joint venture between Sabic and Pecten Arabian Company (itself a subsidiary of Shell Oil Company of the US). Sadaf plans to link the two plants.

Petrokemya's share of the new styrene plant will be 200,000 tpy.

The company has signed a contract to borrow $300 million from Saudi and foreign banks to fund the expansion and to build steam and electricity joint generating units.

A $120 million cogeneration unit is expected to be executed on a build-own-operate basis, according to project sources, and will enable Sadaf to generate up to 200 MW of power from steam, thus reducing the plant's reliance on the eastern power grid. The power will be provided through two gas turbines.

Sadaf is also revamping its first styrene plant.

''It is revamping, not debottlenecking, because we are switching from gas phase to liquid phase alkylation,'' said Sadaf president Mosaed Al Ohali.

''With this switchover, we are realising a small capacity increase, but the money is being spent mainly to upgrade the technology,'' he added.

Sadaf came onstream in 1985 and uses ethane, salt, benzene, methanol and butane to produce ethylene, crude industrial ethanol, styrene, caustic soda, ethylene dichloride and methyl tertiary butyl ether (MTBE).