You may not have heard of it but it is one of the most abundant materials on earth. Lignin is the tough cellulose material at the heart of woody plants.
When fossil fuel reserves are eventually exhausted, the essential by-products of refining will no longer be available. Since these aromatic chemicals are used in many processes including the manufacture of plastics, detergents, fertilizers, pharmaceuticals and synthetic fibres it is vital that alternative sources become available. Lignin (the ‘woody’ part of plants) can be produced sustainably, it is renewable and a natural form of carbon storage. It is a complex polymer made of aromatic chemical building blocks, potential replacements for oil-based by-products.
Until now, breaking down the tough structure was difficult and involved pre-treatment with high temperatures and acids. The University of Edinburgh and Advanced Microwave Technologies Ltd (AMT) are collaborating to develop a novel pre-treatment to break down lignin using microwaves and enzymes.
The project will use Scottish Sikta Spruce in the project and the aim is to obtain an increased amount of aromatic feedstock chemicals from the lignin, without a decrease in fermentable sugars.
Biological treatment methods for lignin are considered green and clean, but rather slow. Methods using acids and heat are energy intensive and environmentally hazardous. Microwaves have been identified as a potential method of pre-treating woody materials but equipment to do this on a commercial scale has not been available, until now.
The AMT patented method of applying precision microwave energy to materials moving through a pipeline means that large-scale, continual processing of a liquid or suspension is viable for industry. AMT’s latest breakthrough developments have extended the range of operational temperatures and pressures, enabling the power of microwaves to be applied to lignin and cellulose breakdown.
The Principal Investigator on the project is Dr Louise Horsfall, a Lecturer in Biotechnology at the University of Edinburgh. The work is supported by funding from the Industrial Biotechnology Innovation Centre (IBioIC), EPSRC Impact Acceleration Account, The University of Edinburgh and AMT. Stephen Roe, CEO of AMT commented, “This collaboration with The University of Edinburgh is a major step forward in accessing the potential of lignin as a replacement for oil-based aromatic by-products and ensuring a carbon-friendly, renewable source of energy and chemicals for the future. We are delighted to work with Dr Horsfall on this important project.”