Together with NRW environment minister Johannes Remmel, Michael Arns, chairman of the NRW Chamber of Architects, Markus Becker, chairman of the State Wood Council NRW and Andreas Wiebe, of Forest and Wood NRW, congratulated the "2013 NRW Wood Award" winners. What is described simply as the development and fabrication of a "Wooden cover for a chemical digester tank" in the citation proves upon closer examination to be a fully fledged feat of engineering: implacably hostile conditions caused by high temperatures, moisture and, above all, extremely corrosive acidic chemicals are encountered in such digester tanks. With the exception of expensive rubber-lined steel, there are only very few materials which withstand attack by hot acids. This was the logical origin of the idea of having such a cover made from special Siberian softwood, a material that possesses the necessary high resistance to such conditions. Although the solution may look so very simple in this case, the cover design is, in fact, an outstanding engineering achievement in wood. With a diameter of 6.5 meters, it consists of multiple layers of bonded plywood. In addition, its inner side is hollowed out like a Chinese wok to improve pressure resistance.

 

Only a few sources in Germany

 

It was therefore necessary, as early as the planning phase, to co-opt suppliers, who, on the one hand, were capable of calculating the stressing and stability of the wooden structure and, on the other hand, could find materials and adhesives capable of withstanding these conditions. Special acid-resistant two-pack epoxy-based adhesives, plus generous helpings of expertise in wood and know-how were needed to make reality of this ambitious project.

 

Wood--an efficient carbon-storage system

 

In addition to its many other benefits, including flexibility and low weight, wood is also notable for the large carbon dioxide savings it makes possible. The production and processing of steel elements, and also of cement and concrete, releases large amounts of carbon dioxide into the atmosphere, whereas a tree actually absorbs carbon dioxide from the atmosphere during its growth phase, and stores it in its wood. One cubic meter of wood thus fixes around one tonne of carbon dioxide from the air, and additionally relieves the environment of another tonne of carbon dioxide which would have been generated if other materials had been used. Sachtleben is thus making yet another active contribution to reducing carbon dioxide emissions and sustainable use of resources.

 

The NRW Wood Award is organized by the State Wood Council NRW in cooperation with the Cluster Forest and Wood NRW, and is supported by the NRW environmental ministry and Forest and Wood NRW.