“We chose Honeywell and Experion PKS because we wanted the best process control solution we could get with experienced project delivery we could count on. The result has been very positive for our company. The project was executed on time and on budget, and Experion has proven to be highly reliable and robust.”

Holger Grotheer, DCS Manager, AOS

Aluminium Oxid Stade (AOS) GmbH was looking to completely revamp its alumina refinery units with minimal shutdowns. The company needed to update its aging AEG control system to help increase safety, reliability and efficiency at its German refinery. The company turned to Honeywell and its Experion® Process Knowledge System (PKS). The control system migration has generated the following benefits:

• Project delivered on time and on budget
• Hot cutover to the new control system avoided process downtime
• Quick and smooth startup and shutdown processes for complex plants realized by sequence flows
• Improved access to process information for faster decision making has helped increase production
• Long-term archiving of process data and events

The AOS alumina refinery is owned by DADCO Alumina & Chemicals Ltd. It is located in Stade in northern Germany. Built in 1973, its major activities are the production of alumina and aluminium hydroxide.

Due to improvements to the process and production facilities, particularly through financial support after 2004 from 100-percent owner DADCO for productivity-based expansions and infrastructure renovations, AOS has been able to increase production capacity from 600,000 to the current level of approximately 1.1 million metric tons of alumina per year. At the same time, specific emissions have been significantly reduced. According to the International Aluminium Institute, the AOS refinery has proven to be the best performing refinery in the world in terms of energy efficiency and intensity with approximately 7GJ per tonne derived from primary natural gas (an industry benchmark) plus equivalent of 1 GJ per tonne as purchased electrical power.

AOS started working with Honeywell in 2003. The upgrade of originally installed wall-mounted panel instrumentation from different suppliers started with Experion.

AOS was seeking a complete revamp of all units with the main implementation work done as a hot cutover to minimize downtime. AOS was looking for low energy consumption, high quality and zero unplanned shutdowns.

System availability and reliability was a major challenge. For the tube digestion area there was no possibility of stopping the flow. This created a problem as the liquid would easily solidify.

Lack of spare parts for old installed equipment and environmental restrictions were the other major considerations.

AOS had the following requirements for choosing a new control system:

• Modern and proven technology
• Redundancy of network and components, such as server, controller, I/O modules
• Hot cutover
• Data historian with fast sample rates for process pressures
• Open system for possible connections/expansions to other subsystems
• Training for engineers and operators
• Service support 24 hours a day, seven days a week
• Service contract for the future

AOS chose to migrate its control system to Honeywell’s Experion PKS for the following reasons:

• Honeywell’s project and hot cutover expertise for chemical plants
• Performance of Experion PKS was best-in-class compared to four other DCS systems
• Very good redundancy concept
• High availability and uptime
• Online migration of control system available
• Integration of video surveillance into control system

Holger Grotheer, DCS Manager, AOS attributes the project’s success to on-time delivery and the continuity of working with the Honeywell project team for five years.

Another key success factor was that Victor Phillip Dahdaleh, owner and chairman of AOS, fully supported the project from the start.

Experion® is a registered trademark of Honeywell International Inc.