Researchers at TU Hamburg are producing climate-neutral energy sources from renewable raw materials such as wood residues and straw. The molecule lignin plays the main role here.

The bioeconomy is key when it comes to the future of the economy. It aims to solve global challenges by replacing fossil resources with various renewable raw materials. One fossil-free alternative, for example, is the molecule lignin. This is found in almost all plants and woody plants, such as grasses, shrubs and trees. Scientists at Hamburg University of Technology, supported by the TU Centre for Bio Based Solutions, are conducting research in the "ELBE - NH" consortium, which is funded by the Federal Ministry of Education and Research, to utilize lignin more efficiently for the bioeconomy.

Fertilizer for agriculture

In a plant on the TU Hamburg campus, an aqueous mixture is used to break down wood residues or straw into their basic components under high pressure and temperature. In addition to lignin, this also produces side streams, known as hydrolysates. The group of engineers from universities, research centers and industry has succeeded in producing lactic acid and chemical compounds from fructose and glucose from hydrolysates. The motivation is familiar from sustainable and economical kitchens: "nose-to-tail", i.e. utilizing all parts of a source. The research team is attempting something very similar with lignin production.

And they have succeeded in valorizing previously unused by-products of lignin production into a sought-after component of the plastics and food industry. "The complete utilization of the input materials and the high added value contribute enormously to increased economic efficiency in lignin production and make it a competitive, fossil-free alternative," according to the consensus of the researchers in the biorefinery groups from the three participating TU institutes. "From the small waste streams that remain, we produce energy or fertilizer for agriculture with the help of biogas plants."

A raw material with great potential

Due to its chemical nature, lignin can be used in a variety of ways, for example as a bio-based plastic or for the environmentally friendly production of medicines and flavorings. Experts therefore see the raw material as an opportunity to revolutionize the healthcare and energy industries, as well as the food supply. The challenge here is to keep the production of lignin economical and competitive with crude oil and other fossil fuels.

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You can find more information on the website of the Institute of Thermal Process Engineering