On September 19, 2007, a new electrolysis plant for the production of chlorine and caustic soda was officially opened at VESTOLIT in Marl. The plant, which was engineered and built by Uhde at Marl Chemical Park, the third biggest chemical site in Germany, was commissioned in April 2007 and is due to be handed over to the customer in the coming weeks. The plant has an annual production capacity of 250,000 tonnes of chlorine, which is used as feedstock at the company's PVC plants, and 280,000 tonnes of caustic soda.

”By investing in the conversion of its amalgam electrolysis plant to Uhde’s latest-generation membrane cell technology, VESTOLIT is making a sustained contribution to environmental protection,” said Lothar Jungemann, the member of Uhde’s Executive Board responsible for electrolysis plants. "VESTOLIT has been manufacturing products at its site in Marl for almost 60 years now. The new Uhde electrolysis plant will strengthen the competitiveness of our company and guarantee our customers and our economic region continuity combined with environment-friendly technology for the future," said Dr. Michael Träger of VESTOLIT's management board on the occasion of the ceremonial opening.

The conversion project involved replacing the amalgam cells in an existing cell room with new Uhde single-element membrane electrolysers. Uhde was responsible for the basic and detail engineering, supply of the electrolysers and appurtenant equipment, the construction work and supervision of the commissioning activities. VESTOLIT has invested some €80 million in the new mercury-free electrolysis plant. Other chlor-alkali electrolysis plants with a combined production capacity of 300,000 tonnes of chlorine and 338,000 tonnes of caustic soda per year are also currently undergoing expansion or conversion to Uhde membrane technology in Poland, Brazil and Germany. In addition, Uhde is also building an HCl electrolysis plant in Portugal. Together, these electrolysis plant contracts are worth €63 million.