new control system supplied, engin- eered and installed by Honeywell Southern Africa, of Midrand, is in its final stages of commissioning at Sasol’s tank farm in Secunda, Mpumalanga.

Known as an oil movement and storage system, the new controls will facilitate the automatic and optimised mixing of predefined recipes for various fuels from production planning.

The system being commissioned works in close association with analysers that monitor the fuels constantly, and any required adjustments are then made automatically to ensure adherence to production specifications.

Further, constant self-diagnostics is carried out on all system components with the required alarms and automatic shutdown in the case of a failure.

It is expected that the system will facilitate in the region of an 8% increase in profits from the tank farm through optimised mixing to the required specifications, as well as a reduction in costs through improved accuracy and efficiency, reports Honeywell engineer Roel Kuiper.

The company has also been acknowledged by Sasol Synthetic Fuels as being part of its supplier-performance monitoring (SPM) system.

Along with other key suppliers, the company received recognition for its contribution towards sustained performance in areas such as price, quality, scheduling and safety.

The SPM programme was started two years ago to improve the performance of all suppliers.

In other developments, an order to replace the control system at Sasol Secunda’s central control-room, after having operated for 15 years, was handed over by the company.

The new system, a TPS 100, has the aim of keeping costs down while maximising benefits through Hi-way gateway nodes which support the original front-end devices in combination with the plant network management node.

This node provides a gateway between the process connected devices and the factorywide management information system.

The system includes true open technology with Windows NT, and provides a platform which will improve operator efficiency through the advanced functions of the human–machine interface.

Features such as an advanced graphic interface, effective alarm management, detailed historisation, trending and comprehensive journals – which were unavailable on the old system – have also been included. The upgrade was undertaken with no plant shutdown being required.

“There are 11 Hi-ways affected by the upgrade, representing more than 11 000 real-time inputs and outputs, as well as 11 process units,” reports Sasol project manager Ernie Smith.

“The implications to the plant with the scale of this project would be significant; thus it was imperative that the supplier selected be able to carry out the upgrade, with the new system running in tandem with the old system, until full changeover is complete,” he explains.

Honeywell was responsible for the data translation from the old system format to the new format, using locally-developed in-house tools based on Microsoft’s Access, to improve the speed of translation, while ensuring its accuracy.

The development of these user-friendly tools is possible since the company has adopted the Windows NT platform as the basis for the HMI and global user station, reveals sales tendering and support manager Zane van der Nest.

“This project is unique in being the first that the South African company has undertaken, providing a turnkey solution based on the New Engineering Contract format of a fixed lump-sum price based on an activity schedule.’ For many years Sasol was the company’s largest industrial automation site in the world, and it is still the largest in the southern hemisphere.

Only recently superseded by some large petrochemical sites in the Far East, the relationship between the two companies engendered leading-edge process technology which was, and still is, respected worldwide, reports Van der Nest.

“Due to the size and complexity of the site, a lot of firsts were achieved in South Africa, and at that time our expertise was independent because of the technological isolation of the past,” he says.

The partnership between the two companies also gave rise to Honeywell Southern Africa’s test and repair facility, the only accredited unit outside of the US.

Originally established to support Sasol, the facility represents an investment of more than R20-million.

The association between the two companies started 20 years ago when the petrochemical group installed a TDC2000, the first true distributed control system available at that time.

Since then the relationship has developed into an ongoing partnership which fosters openness, innovation and development, and which has, over the years, enabled both companies to gain sustainable improvements in their competitive and commercial positions.

The nature of the partnership has evolved over the years, with the control-systems supplier moving from a hardware supplier role to one of solutions provider and integration partner.

“The petrochemical group has come a long way with us through many technology changes and, although careful about making sudden changes, the group has always been among the first to adopt new technology, ” says van der Nest.

The supplier’s commitment to consistent product evolution has enabled the client to evolve from the completely-closed proprietary systems of the past to the supplier’s present fully-open offerings which use off-the-shelf computers for the human–machine interface and management information systems, he explains.

The supplier operates an ‘evergreen initiative’, under which it maintains standard interfaces from its original basic controller through to present products and systems.

This means that, during upgrades, the client’s existing plant wiring can be maintained, and original controllers installed years ago can still be fully utilised.

Since engineers from both companies jointly study the process during the project feasibility phase, it enables potential performance improvements to be estimated, and identifies areas that would benefit from advanced process control.

This shared responsibility ensures that only projects with a demonstratable improvement potential will go ahead, explains Van der Nest.

Many of these projects have achieved payback well within the original estimated timeframe, he reveals.

In addition, as a result of the long-standing nature of the relationship, and the resulting familiarity with the supplier’s products and systems, the petrochemical giant no longer needs to define time-consuming generic specifications at the early stages.

“This means development and implementation time is much shorter,” says Van der Nest.

Honeywell would like to develop similar relationships with its client’s subsidiaries, believing it has much to gain from these partnerships, he reveals.

“As the world’s leading control-solutions supplier to the hydrocarbon-processing industry, we remain committed to this client, and look forward to another 20 years of mutually-beneficial association,” he concludes.

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