Relevance of lignin research for a more sustainable society

Plants use sunlight and water to capture CO2 from the atmosphere to build their biomass. That biomass can then be converted to products that are nowadays made from fossil resources such as petroleum. Whereas the use of fossil resources leads to a net increase of CO2 into the atmosphere (e.g. when burning it as fuel), this is not the case when using plant biomass. For this reason, plant biomass is said to be a renewable, carbon-neutral resource.
Lignin research is highly relevant for a number of applications. One example is the production of paper. In order to make paper from wood, lignin needs to be extracted from it. This extraction process involves cooking of the wood chips in strong alkaline conditions at high temperatures. Wood derived from trees that produce less lignin can be converted to paper using less chemicals and energy, which is positive for the environment.
Another example is the conversion of plant biomass into a range of products that are nowadays made from petroleum, such as fuels, plastics, detergents, etc... In this process, the cellulose is broken down into glucose units by enzymes. The glucose units are then fed to micro-organisms that ferment the glucose into products that are useful for society. Also for this application, lignin needs to be extracted from the biomass, because it prevents access of the enzymes to the cellulose. When the lignin levels are low, the conversion of plant biomass is more efficient.
A third field of interest is the improvement of the digestibility of fodder crops by ruminants. Fodder crops that produce less lignin are more easily digested by ruminants, allowing the production of more meat and milk per acreage. The production of meat has a high impact on the environment. It is therefore even much better to reduce our meat consumption such that more land can be set aside for other purposes such as afforestation and reforestation.
A fourth field of valorisation of lignin research is the production of aromatic molecules from lignin itself. Lignin can be depolymerized by catalytic reduction or pyrolysis into simple phenolic molecules that can be used as building blocks for the chemical industry. Also in this case, the use of plant biomass is a renewable alternative for the use of fossil resources.
Importantly, the plants used as feedstock for the biorefinery should be grown in a sustainable manner, in which forests and fields support biodiversity and the well-being of residents and visitors. Even though plant biomass is essentially renewable, the production of biomass-derived products has an ecological footprint and is limited by the growth speed of the plants. Therefore, also products derived from biomass should not be spilled or over-consumed.

Taken together, research in the Bio-energy and Bio-aromatics group aims at supporting the transition from a fossil-based to a bio-based economy.

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