Steelpaint, the German leader in corrosion protection, has completed a difficult coatings project at a biogas plant near Bremen, Germany, applying its specialist Stelpant system to a double girder overhead crane operating inside a composting hall.
The project at the Nordfuel biomethane plant in Friesoythe involved the complete refurbishment of the 40t crane corrosion protection, replacing a system that had reached the end of its service life due to the severe microorganism induced corrosion typical of a bioenergy plant.
After steel blasting, Steelpaint’s application partner Kruse Oberflächentechnik applied a two-coat system comprising a Stelcatec-L-PR primer and Stelcatec-L-NT topcoat to protect the crane, which is used to redistribute biomass, including woodchip and organic waste.
While there are no specific standardised testing procedures for coating systems used in such facilities, composting halls represent an exceptionally challenging environment for traditional coatings, said Nils Baumfalk, Steelpaint, key account manager, protective coatings.
“Unlike standard industrial facilities, exposure conditions can vary considerably depending on temperature, humidity and the composition of the organic material being processed,” he said. “The atmosphere often contains ammonia, carbon dioxide, organic acids and by-products of biological decomposition that can accelerate the deterioration of conventional protective coatings.”
Steelpaint’s Technical Service Manager Dmitry Gromilin said: “Ammonia-containing atmospheres represent a significant challenge for conventional zinc coating systems, in that electrolyte films, organic acids, and chloride-containing deposits from biological processes can lead to the rapid deterioration of the coating protecting steel.”
Kruse Oberflächentechnik managing director Ralf Kruse said: “The success of this project demonstrates Stelpant’s ability to protect steel in the most difficult of corrosive environments. Long-term protection depends on the overall integrity of the coating system to prevent highly corrosive media from penetrating the substrate. We found the two-coat Stelpant solution provides maximum corrosion protection in the most aggressive industrial environments.”
Kruse had previously gained positive experience with Stelpant on a steel hydraulic engineering project. The successful performance of the coating system in that project was a key factor in their decision to order the coating system again.
Due to its unique binder system this product can be applied at temperatures ranging from -5°C to 50°C and a relative humidity level as high as 98%. The dry film is extremely resistant to fresh- and sea water and provides maximum corrosion protection in the most aggressive marine and industrial environments. The coating has excellent elongation properties within its whole working lifetime.
“Of course, the expected service life of the coating depends on the actual environmental conditions and the level of exposure,” furthered Gromilin.
“Steelpaint has had the best experience with its steel hydraulic engineering coating systems for these demanding applications. The high chemical resistance of the 1K-PU systems, combined with their resistance to constant water exposure, makes these systems ideal for such applications. Especially for repair projects where application must be carried out in high humidity, the moisture-curing 1K-PU systems are unbeatable.”
For this category, relevant standards typically specify coating systems with durability classes H (15–25 years) or VH (more than 25 years). Stelpant meets this criterion.
While challenging, this is not the first use of the Stelpant system in bio-composting halls with Steeelpaint supplying the corrosion protection system for similar applications in biofuel plants and comparable industrial facilities.
A shredder machine is expected to be the next piece of equipment at the Bremen plant to be coated.
About Steelpaint GmbH
For more than 40 years, Steelpaint has enhanced the life and durability of heavy-industry facilities, particularly in the maritime sectors. Thanks to one-component polyurethane resins, the Germany-headquartered company’s special high-tech coatings have raised the technological bar in corrosion resistance, offering impressive benefits over conventional epoxy coatings solutions.
Steelpaint has origins dating back to the 1890s. Its products are used widely in port and offshore facilities, sheet pilings, internal and external linings, tanks, bridges, and ship structures. They can be used in combination with cathodic protection.