Performance Track Record of Composites in Chlorine Manufacturing12 March 2020
For 30 years SABIC has been using composite pipes and assemblies in its Chlorine manufacturing operations. Through the collaboration with Versteden, and using high quality Atlac® resins from AOC Aliancys, these reliable material solutions have enabled SABIC to run its operations in a safe and continuous way, as explained by Thana Kammeijer, Paul Peterse, and Erwin Simons.
At the site of SABIC in Bergen op Zoom (Netherlands), the company is operating a Chlorine plant, making Chlorine, Hydrogen, and Sodium Hydroxide. These chemicals are used in different parts of the site, where various types of thermoplastic resins are produced (including products with established brand names such as LEXAN™ resins).
In the Chlorine plant the Chlorine is manufactured using solid salt as a raw material. At the beginning of the process the salt is dissolved in water. The heart of the Chlorine operation is the Cell room which houses a large series of electrolysis cells, converting the brine into the main product, Chlorine. In this process Hydrogen, Hydrochloric Acid and Sodium Hydroxide are produced as by-products.
After the electrolysis, the gas streams of Chlorine and Hydrogen are compressed. The compressed Hydrogen is transported through pipelines to a boiler for conversion into steam. The compressed Chlorine is liquefied and sent (in liquid phase) to another production unit at the site. The side streams of Hydrochloric Acid and Sodium Hydroxide are pumped into storage tanks, awaiting further processing. As part of the Chlorine drying process, concentrated Sulfuric Acid is being used.
“We want to make sure that chemicals like Chlorine, Hydrochloric Acid and Hydrogen remain inside an enclosed environment and are well-contained”, explains Thana Kammeijer, Manager Chemical Operations Chlorine Unit at SABIC. “In that way we ensure that the plant is a safe place to work, and that we are running our processes in a responsible way. At the same time, we do not want an eventual equipment failure to interrupt the continuous operation of the Chlorine Unit, as this may affect the downstream processes on this site. Therefore, we closely follow the condition of all piping and equipment, and take the right actions for preventive maintenance.”
The Chlorine plant was designed by German Engineering Company UHDE, and has been in operation since 1987. “The brine, Hydrochloric Acid, Sulfuric Acid and Sodium Hydroxide are obviously highly corrosive materials”, comments Paul Peterse, Mechanical Integrity Engineer at SABIC. “For that reason composites pipes and vessels have been used right from the start. In some applications we chose to use pure composite piping, while for other applications (including wet Chlorine gas streams) we selected composite pipes with thermoplastic liners (like PVC, PTFE).”
Paul Peterse worked with composite materials for more than eleven years. He is one of the leading engineers at the site to monitor the integrity of the Chlorine plant operations. “We inspect pipes and pipe connections continuously in order to understand their condition and minimize the risk of potential leaks”, he adds. “We use mostly visual inspection methods, and to some extent X-ray and Ultrasound techniques. This gives great insight into the condition of the parts, and confirms composites are very reliable construction materials for contact with corrosive chemicals at elevated temperatures.”
Every four years the chemical plants on the Bergen op Zoom site are subject to a planned extensive turnaround. This enables execution of larger maintenance jobs and equipment modifications for process improvements. It also allows detailed inspection of pipes and vessels. Through the inspection of the composite components it is determined whether these can remain in operation for another four year cycle, or whether they need to be replaced.
Quality and Consistency
Many of the pipes, fittings and assemblies used by SABIC in Bergen op Zoom have been supplied by Versteden (Bergen op Zoom, Netherlands). Versteden was involved in the construction of the Chlorine plant in 1987 and has been supporting SABIC ever since.
“In the early years SABIC in Bergen op Zoom was cautious using composites and replaced pipes and tanks in critical areas every eight years”, comments Erwin Simons, Technical Director at Versteden. “Since then, we have worked with SABIC and learned together how these materials perform over a longer period of time. As a result we were able to extend the lifetime of composite components and assemblies through optimizing part design, fine-tuning part production processes and improving overall quality consistency.”
“During part production at Versteden all elements of the process are monitored and recorded, so we can trace any anomalies”, Erwin continues. “Our employees in production are well trained and certified by external parties in the processing of composite materials.”
Versteden uses Atlac® 580, Atlac® E-Nova FW 2045, and Atlac® 382 resins from AOC for making the composite components. “We like to work with AOC. The Atlac resins have a long track record of consistent performance in pipes and assemblies used in chemical plants. The great resin quality gives us a huge predictability and consistency of our production.”
Solid Future for Composites
Besides working at SABIC in Bergen op Zoom, Paul Peterse is also actively involved in the education of young engineers at the HU University of Applied Sciences Utrecht. He explains to them the benefits of composites. “Many of my students quickly realize that steel has its limitations, and therefore for corrosive environments composites are a better alternative. I help them to gain insight in the use of composite parts in chemical plants by providing design and inspection guidelines. Based on my experience over the years, I can tell that composites will be the material of choice.”
“Keeping my plant in the right condition and knowing that the chemicals stay where they should be, are my highest priorities”, adds Thana Kammeijer. “I am very happy that through all these years composite solutions have proven that they are capable of performing under such tough environmental conditions. And that we can also rely on knowledgeable partners like Versteden and AOC to make these materials work for us.”