Iris Lewandowski: Biobased resources as feedstock for the bioeconomy

Iris Lewandowski
Professor, Dr., Chief Bioeconomy Officer (CBO), Chair of Biobased Resources in the Bioeconomy 
University of Hohenheim
Institute of Crop Science, Department of Biobased Resources in the Bioeconomy (340b)
Germany 

iris_lewandowski@uni-hohenheim.de 



The Earth receives 1366 W/m2 (2,500,000 EJ) of solar radiation per year, of which 0.25% is converted into usable biomass by the process of photosynthesis. Around 175,000 million tons of carbon, equivalent to about 300,000 million tons of biomass, are sequestered by the Earth’s vegetation each year.

Given that carbon (C) is the main building block of most of the chemical compounds we produce and consume, our economy could be described as a carbon economy. Before humanity discovered fossil oil, coal, gas and uranium and learnt to put them to use, biomass met all human needs for food, energy and materials. Today, a return to the use of renewable C from biobased resources is necessary to avoid the further exploitation of limited fossil resources, the use of which is the main contributor to increasing atmospheric CO2 concentrations and the subsequent global warming effect.

Both, biobased and carbonaceous fossil resources are derived from biomass that has been built through the process of photosynthesis. In this process, plants and algae take up CO2 using energy from the sun. They convert light into chemical energy by incorporating C into their organisms. The C bound in fossil fuels was absorbed from atmospheric CO2 millions of years ago. Biobased resources, on the other hand, consist of biomass that has grown much more recently. Here, the CO2 is removed from and returned to the atmosphere within a short time period of 1 to <100 years.

This “CO2 fixation” lasts as long as the biomass is used as material, e.g. in building materials, or incorporated into soil organic matter. If the biomass is used for energy, the same amount of CO2 is returned to the atmosphere as was fixed in the photosynthesis process. Using biomass instead of fossil fuels keeps fossil C in the ground, thus mitigating climate change. The bioeconomy applies these processes and uses biobased resources as its renewable feedstock.

The bioeconomy is an operational, cross-sectoral approach to a circular and sustainable economy. The most recent description of the bioeconomy comes from the International Advisory Council of the Global Bioeconomy Summit (IACGB, 2024): “The bioeconomy is the production, utilization, conservation, and regeneration of biological resources, including related knowledge, science, technology, and innovation, to provide sustainable solutions (information, products, processes and services) within and across all economic sectors and enable a transformation to a sustainable economy. The bioeconomy is not a static notion and its meaning is continually evolving.” The last sentence points out that the bioeconomy is a dynamic field. With its great potential to provide solutions to pressing societal challenges, such as climate change mitigation, healthy food supply and sustainable use of natural resources, the bioeconomy is emerging as a global concept. As of 2024, more than 60 countries had dedicated or related bioeconomy strategies.

Biobased resources are all resources containing non-fossil, organic C recently derived from living plants, animals, algae, microorganisms or organic residues and waste streams. Together they are often referred to as ‘biomass’. This can be both edible biomass (e.g. rich in protein, starch, sugar or oils) or non-edible lignocellulosic biomass from dedicated crop production, residues and organic wastes. Early potential analyses have shown that, beyond the needs of food and feed production, lignocellulosic biomass in particular would be available in quantities even greater than global energy consumption. However, limits to the sustainable supply of biomass and competition with food production land and biodiversity are often cited as criticisms of bioeconomic development. Biomass is an almost ubiquitous resource, but it is widely distributed. This is a major difference from fossil resources, which are mostly point sources. Biobased resources are distributed not only in space but also in time, with peaks during harvest periods, and can vary in quality. Regional availability also depends strongly on site conditions that determine the physical potential for biomass growth, productivity and production intensity, as well as the infrastructure for harvesting, processing, storing and transporting the biomass. This makes a reliable estimate of the technical availability of sustainably produced biomass challenging.

In line with sustainability goals, the bioeconomy employs approaches such as the food-first principle, cascading use of biomass, life-cycle thinking and multifunctionality, optimizing energy and nutrient use, conserving biodiversity, promoting soil health and agroecological practices. The optional allocation of biomass to different uses is guided by the prioritization of healthy food supply and the cascading principle, i.e. the continuous use of resources for various purposes, optimally through different material reuse phases to preserve the ‘added value’ of products for as long as possible. Multifunctionality involves the integrated production of biomass for food, feed, material and energy uses in sustainable agriculture and forestry, together with the provision of ecosystem services such as soil carbon sequestration, soil and landscape regeneration and pollination services, to name but a few.

Biorefinery approaches apply cascading use and circularity and are important to exploit biobased resources efficiently. Biorefining is an integrative concept for the sustainable processing of biobased resources into a range of marketable, value-added products, including chemicals, materials, fuels and energy, operated with the aim of full utilization of biomass. An important example of the application of biorefinery technologies is the recycling of plant nutrients during the processing of biomass or from its products or from organic wastes. The resulting ‘biobased’ or ‘recycling’ fertilizers close regional nutrient cycles and can replace a major part of synthetically produced nitrogen (N) or fossil-based phosphorus (P) fertilizers. Replacing synthetic fertilizer by recycling fertilizer reduces CO2 emissions, as the production of synthetic N fertilizer is associated with annual emissions of 310 million tons of CO2. The use of recycled N and P fertilizers also reduces the use of fossil resources and imports, supporting regional and reliable supply chains and the resilience of agricultural systems.