Let’s run a simple test. Within 5 seconds, list all the recycling containers that come to mind. Ready? It shouldn’t be too difficult. Plastic, paper, glass, organic waste…it seems very sustainable. Perhaps if you have a few more seconds you can come up with a few more things like an oil depot or a battery recovery location. But something is missing, and that is wood. You could call it the ugly duckling of recycling. Currently, the main disposal method is mainly to use it as fuel in power plants, dump it in a landfill, or in the best-case scenario turn it into chipboard. Fortunately, an EU-supported project aims to change this and open up new possibilities for recycled wood. CaReWood (Cascading Recovered Wood) is an acronym for various procedures for recovering and reusing large pieces of wood and giving them a second chance.
But why aren’t there more wood recycling schemes out there? Besides technical and cost reasons, the main obstacles lie in the veneers and chemical treatments that are commonly applied, compared to the widespread use of DDT and wood in the past. Toxic substances such as PCBs are frequently used. PVC particles and lead-based paint residues may also be present. European regulations require these substances to be destroyed as they may pose a health hazard. In Germany, one of the European countries, where plantation programs are more firmly established, the Fraunhofer Timber Institute WKI, together with 15 other partners in five European countries, is working with large timbers, usually pillars. developed a set of protocols to retrieve , transverse beams, etc. Currently, this process he consists of two stages.
- Hazardous chemical detection and stress testing. This initial stage uses advanced spectroscopy, X-ray fluorescence, chromatography, and spectrometry techniques to assess the amount of contaminant and the depth to which it penetrates the material. Some of these methods can detect wood preservatives, while others are better suited to discover traces of heavy metals. Following this process, scientists also check the wood’s bending resistance and mechanical stability.
- Decontamination. After the parts pass the first test, the cleaning process begins. Researchers at the Fraunhofer Institute have shown that contaminants rarely extend more than a few millimeters above the surface. Therefore, another set of techniques such as rotating brushes, sandblasting with different abrasive media and sawing has been developed to clean the wood.
The results are so encouraging that pilot tests are already underway to help restore a 150-year-old teak bridge in Myanmar – the world’s longest bridge of its kind. The pillars, some as long as 10 meters, are reused as handrails and rest benches along the 1.2-kilometer structure.
Germany will soon pass new regulations that will focus on recovering timber rather than destroying it at the end of its useful life. I hope these rules apply in other European countries as well.
Advantages of the new wood recycling system “CaReWood”
This ambitious project has several advantages, some more prominent than others.
- Deforestation in Europe and other continents may slow and reverse due to reduced wood consumption.
- Burning contaminated wood is avoided.
- Reduce waste.
- Recovery of old wood, often with higher durability and durability, as it was taken from slow-growing trees decades ago.
Fuente: Fraunhofer Institute
