Holding it together: Startup plans first sawdust processing plant in Scotland

Sonichem
Sonichem has found a way to extract lignin – “nature’s glue” – from trees.

A team of researchers in Scotland is supporting a clean tech startup to transform low-value co-products from the forestry sector into eco-friendly alternatives to chemicals found in everyday items.

Sonichem says its ambition is to reduce the reliance on petrochemical-derived ingredients in industries such as cosmetics, packaging and pharmaceuticals. Using its patented ultrasound technology to break down forestry co-products – including woodchips and sawdust – the company extracts natural compounds that can be transformed into green alternatives to essential chemicals.

A recent feasibility study funded by the Industrial Biotechnology Innovation Centre (IBioIC), with support from the University of Glasgow, has helped the business to take its technology to the next stage. Sonichem is working towards the opening of its first commercial plant in 2027, which is expected to be based in Scotland and will process up to 15,000 tonnes of forestry material annually.

The UK generates approximately 4.5 million tonnes of wood residues every year. Only 55% of logs that enter a sawmill become usable construction timber, while the remainder ends up as co-products such as woodchips and sawdust.

The target organic substance being collected through Sonichem’s process is lignin – a polymer that acts like a natural glue, binding the cells and fibres in trees and other types of plants together. This property makes it well-suited for use in products such as resins, films, coatings and foams.

While naturally occurring lignin from sawdust is not immediately transferrable to these types of products, the researchers used a series of chemical reactions to create compounds that better matched the synthetic counterparts and could be used in manufacturing.

Andy West, chief chemist at Sonichem, said: “Compounds derived from petrochemicals are the building blocks for so many of the products we use every day, but to achieve net zero that needs to change. Trees are a great natural resource that could become part of the supply chain and lignin, in particular, is highly versatile and can be used in almost any setting. But, it is the natural glue that holds a tree together, which makes it difficult to extract. In the past, we explored various methods before developing the ultrasound technology to do so effectively.

“The next step in the process is about engaging with both the manufacturers already using resin, as well as the forestry sector, to ensure that the right number and type of trees are planted now to secure the availability of the product for years to come. This project has been an important stage in the commercial development of our offering and the creation of our first biorefinery plant.”

Professor Dave Adams from the school of chemistry at the University of Glasgow, said: “Working with Sonichem, we have been able to modify the base lignin extracted from sawdust to turn it into a range of more useful chemicals. Of the five routes we tried, all five worked well, which is highly promising and gives the business the information needed to scale up this initial work to a commercial level.”

Dr Liz Fletcher, director of business engagement at IBioIC, added: “Scotland’s forestry sector is worth over £1 billion to the economy, but there is potential to see this grow by using the biomass that sawmills generate in manufacturing. Sonichem is a great example of a business looking at alternatives to petrochemicals from a feedstock otherwise used for low value applications. Up to 270 million tonnes of synthetic resin were used globally last year, highlighting the sheer scale of the opportunity to improve the sustainability of the chemicals sector.”