German chemicals producer Evonik (Essen; www.evonik.com) has started up a thin-film composites plant at its Marl / Germany site to coat membranes for use in organic solvent nanofiltration and gas separation. The company’s hydrophobic polyimide membranes sold under the brand names “DuraMem” and “PuraMem” are used in processes facilitating efficient recovery of valuable homogeneous catalysts, solvent recycling, or gentle processing of natural oils.

In the new composites plant, thin membrane films are coated with speciality silicones or other materials and in a further production step converted into solvent-resistant or gas-tight spiral-wound modules. The resulting silicone coating, which is also manufactured by Evonik, is a “key factor for the separation properties of the membrane,” the company said. The new products are to be launched on the market in the second half of this year.

Matthias Kottenhahn, head of the High Performance Polymers business line, called the start-up of the thin-film composites plant “a consistent step in our growth plan for the attractive membrane business,” adding that it will give customers direct access to an advanced membrane technology for resource-efficient material separation. Thanks to membrane coatings customised at the molecular level, Evonik’s technology offers the advantages of lower energy consumption, higher yield, and particularly high separation precision, Kottenhahn said.