Turnaround at Dow — time is money

TÜV SÜD engineer Olaf Fuchs is a forward-looking planner. He started working on his latest project approximately 30 months in advance: the turnaround at the Dow chemical plant in Böhlen, Germany — a so-called shutdown for safety and maintenance purposes.

In Germany regular inspections involving the total shutdown of process plants are required by law for inspection, safety tests, maintenance and repair. The Dow Chemical plant in Böhlen, Germany, recently engaged TÜV SÜD Chemie Service to assist DOW with the shutdown in order to ensure the safety of the plant up to the next periodic inspection.

Every day of shutdown in the chemical plant in Böhlen means approximately €1 million loss of turnover. It is no surprise therefore that Fuchs put a team of experts together for this project: “For this turnaround, we teamed up another 10 expert witnesses from our Germany-wide branch offices in addition to our 10 experts in Schkopau.”

The men have a lot of experience and knowledge with regard to this plant, and without long-term practice in the chemical industry they couldn’t, for example, properly assess occurring corrosion. “Today’s machine-created welding seams cannot be compared to those from years ago,” said Fuchs. “However, this does not mean that they are not important.”

The heart of the olefin complex is the so-called cracker. The petroleum is directly supplied from the harbour in Rostock to the Dow chemical plant via a pipeline more than 430 km long. In the cracker, the naphtha is cracked into hydrocarbon compounds such as ethylene and propylene in 15 furnaces at approximately 800°C. Böhlen supplies the plants in Schkopau and Leuna with intermediate products. There, they are further processed and turned into high-quality plastics.

The cracker also supplies other parts of the plant with process steam, which presents a disadvantage. “When the cracker coughs, everything coughs,” said Fuchs. And before the cracker can be inspected, all other parts of the plant need to be shut down and maintained. This alone takes 10 days.

During the large-scale shutdown, approximately 1200 employees from different third-party companies are working on the premises. Usually, there are only nearly 600 Dow employees and 300 external service staff. The logistics on the 320 ha premises are enormous for this turnaround. The material storage alone comprises, among others, two tents with 240,000 parts, 290 shower and changing room containers, 50 containers for granting the work permission on site, 63 office containers and a kitchen tent. For accessing the plant, a large car park with its own traffic lights was created.

The technical check of the plant entails tremendous effort and needs to comply with safety regulations. The different trades and employees jointly dismantle the respective installation, check it, replace or renew parts and afterwards assemble everything again.

The turnaround team members need to coordinate around 1200 to 1500 jobs with a total of 25,000 sequences (individual tasks). Everything is closely interlinked. “For example, there is no point in getting all the people here in order to check something and then you don’t have a security officer,” said Reiko Hass, turnaround manager at the plant. “In order to start working, we need safety officers, a crane, scaffolding and the correct material.”

In order to ensure a smooth process, planning is coordinated with everyone in advance and documented in a roadmap. All construction and spare parts are ordered in advance in all sizes in order to avoid delivery delays. During the shutdown, the adherence to the project schedule is checked. Dow closely monitors the project because next to the 50 days of shutdown, which cost €50 million, the company invests another €45 million in maintenance costs and technical innovations.

In this turnaround, the legal-related, statutorily prescribed checks form 80% of the work packages. These include the corrosion monitoring of all construction components. Thus, for example, a total of 100 nozzles at the vessels needed to be replaced due to corrosion. The replacement of each component is precisely documented. When the plant is started again after the check-up, Olaf Fuchs’ team is still working on the documentation for some time. Every step carried out by TÜV SÜD Chemie Service must be fully documented for future reference should the need arise.