More Sandvik equipment for Iran gas field
1 Mar 2010
Fellbach, Germany – Sandvik Process Systems is to supply the sulphur solidification and handling echnology for phases 17&18 of Iran’s South Pars gas field development. The order, scheduled for delivery before the end of 2010, is the third to be secured by Sandvik as part of the development of this huge field, confirming the company’s Rotoform-based granulation technology as the preferred sulphur solidification solution at South Pars, Assaluyeh.
The Iranian South Pars gas field, the northern extension of Qatar’s North Dome field in the Persian Gulf, is estimated to hold reserves in the region of 14 trillion cubic metres, making it one of the world’s largest gas fields. Discovered in 1993 and on-stream since 2002, the field will have a peak annual production of 49 billion cubic metres.
The overall project is owned and managed by Iran’s state-owned Pars Oil & Gas Company (POGC) and its development is being rolled out in around 30 phases. The solidification and handling system for phases 9&10 has already been precommissioned and will go into operation later this year. Main contractors are Oil Industrial Engineering and Construction Company (OIEC) of Iran and GS of Korea.
Delivery for phases 15&16 is scheduled for early 2010; main contractors are Sepanir of Iran and Salzgitter of Germany. Phases 17&18 are being managed by Industrial Projects Management of Iran (IPMI), a consortium made up of Industrial Development & Renovation Organisation (IDRO), OIEC and Iran Offshore Engineering and Construction (IOEC).
This latest order includes three Rotoform High Speed granulation lines including pumps, filter, preconditioner and cooling water system, delivering a solidification capacity of 800 t/d. The use of multiple systems allows preventive maintenance to be carried out on individual lines while the other lines remain fully operational.
As with both previous contracts, Sandvik is also supplying handling, storage and truck-loading systems including collecting conveyor, bucket elevator and storage silos.
In the early phases of the South Pars project, sulphur solidification was undertaken using drum technology but this suffered from quality issues and high maintenance requirements.
“We were able to demonstrate superior performance in both these areas,” said Sandvik sales manager, Ulrich Nanz. “Our Rotoform system delivers a 100% premium quality, dust-free monogranule of 3 mm in diameter. There’s absolutely no need for size classifying equipment or remelting of off-spec product. In terms of maintenance, each line needs to be stopped for an hour a week for cleaning, then once a month for preventative maintenance.”
The Rotoform system is based around a heated, cylindrical stator and a perforated shell that turns concentrically around the stator, depositing sulphur drops across the whole operating width of the steel belt.
Water is sprayed onto the underside of the belt as it travels along the system and the heat released during solidification and cooling of the pastilles is transferred by the stainless steel belt to the cooling water. At no stage can the water come into contact with the sulphur, so there is no risk of cross-contamination, and the cooling media can be reused over and over again.
At the cooler end, pastilles are taken off with a discharge knife and pass via a chute to a collecting belt. A discharge temperature of less than 70°C ensures that they are already solid and free-flowing as they leave the cooling belt. From here they are transported to storage silos ready for loading into trucks.
Solidification is said to take less than 10 seconds and the short residence time of the sulphur on the steel belt means there is little time for H2S to escape, resulting in very low emission values. Similarly, low levels of sulphur dust levels mean there is no need for exhaust air treatment with wet scrubbers or cyclones. The electrical consumption requirement is stated to be less than 3kWh per tonne.
