Spot the difference

19 September 2022


The BioComposite Centre’s Dr Morwenna Spear explains the differences between the bioeconomy and the circular economy and how the wood-based panels industry fits both

Our world is increasingly interested in green growth, whether this is individual governments setting targets or blocks of nations such as the EU setting out their Green Deal. This mirrors our increasing awareness of the finite nature of resources, and the urgent need to reduce industrial emissions, cut down waste and solve a multitude of sustainability challenges.

Two pillars are often mentioned in connection with green growth – the circular economy and the bioeconomy. Both offer great opportunities to address some of the issues named above. But both are distinct, and may work in different ways. Let’s consider how the wood panels industry fits both.

First the bioeconomy. This ranges from agricultural production through to biotechnology, and includes forestry and fishing. It also covers many tiers of supply chains between the initial grower and the final manufacturing technologies and value adding stages. This includes food processing, wood products, green chemistry and many others. It is a multi-billion pound industry in the UK alone, due to its vast scope.

By their very nature wood-based panels fall within the bioeconomy – using wood for the strength-giving component of panels. It’s increasingly likely that bio-based resins will become widespread over the next decade, increasing the bio-based content of boards. There is scope for bio-based additives in wood-based panels too – waxes could be plant derived, while fillers and hardeners may already be formed from plant materials. Bark tannins have long contributed to resin cure and ground nut shells or bark can act as fillers in plywood adhesives. The role of wood panels for the bioeconomy, and thus how the industry supports a national or global shift towards bio-based materials across society is an important message.

Next the circular economy. Here there is a desire to close the loop, to reclaim products at the end of their service life and return them for recycling. Of course the waste hierarchy doesn’t just mean recycling, with a preference for re-use and repair, but can also go as far as processes where smaller elements (even down to the molecular level) can be retrieved to build new feedstocks. There is also the collection and use of byproducts, which also reduces waste and can increase the efficiency of the system. A good example is using bark to generate new bio-resins, while the main product, the timber becomes plywood.

Key issues in the circular economy are collection of the end-of-life materials, and establishing supply chains to return them to suitable new manufacture. For wood-based panels many countries have well established wood recycling schemes. Particleboard has a prominent role in forming the next generation of products from wood wastes. However, issues exist in the uncertainty about the type of panel, what glue, and additives or treatments that it may contain.

Some waste collection and sorting schemes limit the future life of reclaimed products to only certain applications. Other schemes have sought to establish tighter loops, to connect materials of known origin and composition (for example, reclaimed MDF from shops and industry) with technologies to reclaim the components in a more efficient manner (in the example, MDF Recovery’s technology to separate fibres for MDF production). More of these tighter loops are needed.

Sorting and recognition technologies can increase quality control so that feedstocks are better utilised. There is an urgent need to reduce the losses of good wood into low quality uses at end of life (for example, reclaimed wood for biomass energy). A shift to increase labelling and an improved flow of knowledge through the system would boost confidence in the strength or characteristics of reclaimed solid wood. This could enable reuse in structural applications; formation of new laminated structural products; or conversion of end-of-life plywood into products which harness its inherent strength.

Next time you are discussing the benefits of panel products, remember there are two very strong cases to be made. Wood-based panels already play a leading role in the bioeconomy, and this will continue. The wood panels sector also has a long track record of circularity, and new examples are emerging in which tighter loops can create a greater number of passes through product lives before the wood fibre is ultimately returned to energy and CO2 to be re-assimilated into new biomass by trees.

The bioeconomy includes forestry. PHOTO: STEF KAISER
Wood waste can be part of the circular economy