The circular economy, the continuing reuse and recycling of raw materials into new uses is a concept that has great resonance with the wood industry.

Timber is a material that lends itself to be used more than once, whether that is the reuse of timber beams, repurposing from beams to furniture or remanufacture into composite products such as chipboard. However, whilst the material lend itself to the circular economy does our industry and its practices promote the circular use of timber?

The UK produces around 5 million tonnes of wood waste per year and over 1.5 million tonnes is already recycled into new products. A similar amount is recycled in to biomass for energy production and over a quarter of a million tonnes of used wood is exported.

Much of the timber that is recycled is used in the panel and animal bedding industries, however, this has to be clean wood and here is the potential issue.

Clean wood is wood that has not been treated, preserved or has been painted with toxic paints. The limits for chemicals within the wood are strictly controlled and, for the panel industry, set to the same levels as the toy standard (BS EN 71 part 3).

But, the industry has been using chemicals to increase the service life of timber for many years and many of these chemicals have now been found to be unsafe in application, use or at the end of life. Indeed, some treated timber should be disposed of as hazardous waste, with only the potential for energy recovery through Waste Incineration Directivecompliant CHP plants.

However, this may well change. As sorting technologies become more efficient and the use of IT becomes more common there is the opportunity to develop sorting processes that will be able to automatically identify contaminated timber (whether mass timber or chip) and sort these to reclaim the clean portion of timber.

This will have added benefits above and beyond the cascading of the timber into other markets but also reduce the need for virgin timber in that product and therefore allow timber to be grown for more valuable applications, such as furniture or even construction timbers. This in turn will allow for the increase in potential for the long-term storage of carbon through the use of timber.

Whilst preservative treated timber causes one set of issues for the development of a truly circular economy for wood and wood fibre, the manufacturing of composite materials gives another challenge. However, this is being addressed through research funded, in part, by the UK government.

MDF Recovery Ltd with research partners including the BioComposites Centre at Bangor University has developed a method to recover the fibres from used MDF. This system allows the fibres to be recovered and any laminate facing to be removed. The fibres can then be recycled back into MDF or cascaded in to new products such as insulation.

The circular economy and use of timber is one part of the bigger picture of how the use of timber can fight climate change. Maximisation of the life span of the fibre, in whatever form it is used sits alongside the premise that not only can you substitute the use of carbon intense materials with the use of timber but also that the act of growing timber will take carbon from the atmosphere and lock it away for the life of the products that are made from the timber.

The longer we can keep the timber or at least the carbon, in-service the better it is for the environment.