From straw to plastic: Pulp by-product becomes feedstock for nylon and Perlon

The following text has been machine translated from the German with no human editing.

Turning industrial by-products into reusable raw materials is the basic idea behind the circular economy. The LiGNUM project is putting this idea into practice: material flows from pulp production are to be converted into building blocks for new plastics with the help of microorganisms – thereby replacing petroleum-based raw materials. The fact that this is happening in the region and at the same time is being networked supra-regionally is the icing on the cake.

This transformation is being supported by an interdisciplinary research network coordinated by Christoph Wittmann at Saarland University. Over a period of three years, partners from science and industry are working together to develop sustainable polyamides and test their industrial feasibility. "Our aim in the consortium is to produce industrial polyamides in a sustainable manner, up to pilot scale," says the scientist. "We" refers to the LiGNUM consortium, which will be funded by the Federal Ministry of Research ( e Forschung, Technologie und Raumfahrt) from February 2026. In addition to Saarland University, the German Biomass Research Centre and the Leibniz Institute for Agricultural Engineering and Bioeconomy are also involved, as are industry partners Tecnaro GmbH, specialists in bio-based polymers, and Essity Operations Mannheim GmbH, which most people will be familiar with through its brands such as "Tempo" and "Zewa".

"Polyamides, i.e. nylon or Perlon, are among the 'strongest' plastics on the market," says Christoph Wittmann. "We know from previous projects, such as the production of plastic building blocks from polystyrene waste, what is technically possible. Now we want to use this knowledge to produce several raw materials for polyamides using targeted biotechnology," says Christoph Wittmann. To this end, the project relies on a microbial production system that is suitable for the synthesis of various plastic building blocks.

The raw materials required for LiGNUM come from a by-product of pulp production. Partner Essity uses straw from agriculture as a raw material for hygiene paper in its pulp mill. This produces a lignin-based material stream that is marketed under the name InnoLig+. "At the Essity site in Mannheim alone, tens of thousands of tonnes are produced each year – an order of magnitude that makes industrial use fundamentally possible," says Christoph Wittmann. The aim of the project is to tap into this bio-based material stream for the production of plastic building blocks using biotechnological processes.

"Until now, the key raw materials for polyamides have been produced predominantly using petrochemicals – based on fossil raw materials and in energy-intensive processes known as 'black chemistry'. LiGNUM is pursuing an approach based on the principles of green chemistry: bio-based material flows are to be converted into plastic building blocks with the help of microorganisms, thus replacing petrochemical production methods in the long term," says Christoph Wittmann.

At a glance:
The project "LiGNUM – Microbial refinement of lignin-based streams into sustainable biomaterials" is funded with around 1.55 million euros by the Federal Ministry of Education and Research. Around 940,000 euros of this goes to Christoph Wittmann's team at Saarland University.

Project partners are Tecnaro GmbH (Ilsfeld), the Leibniz Institute for Agricultural Engineering and Bioeconomy in Potsdam and the German Biomass Research Centre in Leipzig; Essity Operations Mannheim GmbH is involved as an associated partner. The project started on 1 February 2026 and will run for 36 months.

Further information:
Prof. Dr. Christoph Wittmann
Tel.: (0681) 30271971
Email: christoph.wittmann(at)uni-saarland.de 
www.isbio.de