From trash to treasure – finding new value in agricultural waste with Tensei

Can we move away from fossil fuels to produce strong, durable materials from alternative sources? And can we explore using by-products of the agricultural industry to make high-value products such as cars, bike frames, wind turbines or plane parts?

Tensei is a biotechnology company that specialises in finding new uses for agricultural waste, and replacing wood and plastic-based materials with more sustainable options.

The company strategy to tackle our reliance on fossil fuel-based materials is to focus on what they call ‘the ‘Second Harvest’ – using agricultural waste streams as sources of alternative natural fibres to engineer innovative, carbon-neutral materials that are also affordable.

Lignin from recycled and non-wood paper waste

Tensei’s team of non-wood fibre experts is growing a global database of plant fibre alternatives and their performance capabilities. They spotted that the paper industry has started to work with recycled and non-wood fibres to reduce demand on virgin wood pulps. These activities produce a black liquor by-product rich in lignin, which is a structural biopolymer found in wood and plants. Could this be an alternative source of carbon with lower production costs?

In this project, Tensei and iCAST worked together to extract lignin from black liquor residues produced by the non-wood paper industry. To start with, the teams investigated how different liquor composition (crop type, pulping methods and extraction methods) affected the purity and properties of the extracted lignin, and then identified which feedstocks and processes yielded lignin with ideal properties.

Starch for paper pulp additives from fruit waste

Starch is a biomolecule found in abundance in nature. It is produced by most green plants for energy storage and can form a sticky hydrogel that can be used as a cheap, degradable, reversible, and sustainable alternative to traditional adhesives –which traditionally contain harmful compounds. 

Starch is a popular choice to produce eco-friendly adhesives. It’s mainly used for packaging and labels by the paper industry, and usually sourced from cull potatoes and food production scraps. However, the eco-adhesive industry is growing, and other non-competitive sources of starch need to be investigated to meet this demand.

Tensei wanted to explore if fruit waste could be valorised to produce starch for adhesives, paper additives or even starch films, not only helping to meet the growing demands for reversable adhesives, but also offering a more circular alternative to source starch. To this end, the team wanted to explore methods to extract starch from fruit waste, obtaining a good yield and high purity while minimising the use of chemicals.

The iCAST team helped by characterising the valorised starch. Identifying the adhesive strength of the gels, their thermal and rheological properties, as well as the balance between distinct types of starch (amylose and amylopectin) to gain a comprehensive understanding of these materials.  

As a result of these two projects, Tensei gained valuable insights into the composition and properties of both lignin and starch coming from different biomass sources. Tensei has now allocated more resources for in-house R&D to continue exploring the potential of alternative biomass sources.

The company is also currently preparing a grant proposal with the University of Bath for the Horizon Europe Research and Innovation call, with the goal to establish an industrial-scale lignin extraction process to develop a new generation of advanced technical materials.

FIND OUT MORE ABOUT OUR JOINT INDUSTRY PROJECTS