Towards net zero land biotechnology – a potential assessment for selected bioprocesses in Germany

To stay within the planetary boundaries transformation to a more circular economy is key, necessitating the consequent utilization of residues as resources. The circular material use (CMU) in Germany is only 12.2% that is below EU average, with biomass CMU of 7.6% being particularly low. On the other hand, Germany has about 240 Mio Mg a-1 dry mass of biogenic residues accruing, which are not well valorized yet [1]. Biotechnological processes will play a crucial role to leverage biogenic residues for providing value-added products in a circular economy [2]. To accelerate increasing CMU the feasibility of biogenic residues for the wide range of biotechnological processes needs to be assessed.

Biogenic residues are heterogeneous while established bioprocesses typically demand specific compounds as substrates. To bring together resource quality with the dedicated demand, we categorized the residues compiled in the DE biomass monitor regarding their biochemical composition, and thus feedstock potential. 95% of biogenic residues were organized into a resource matrix, detailing their fractions and the quality of available data. Three biotechnological processes, making use of lignin, non-fibrous carbohydrates, and oil, respectively, served as model processes to assess the biogenic production potential. Material flows based on state-of-the-art conversion routes will be presented, depicting that residue-based production via all three biotechnology examples can meet national demands of specific polymer precursors, medium chain carboxylates, and platform chemicals, respectively, when only 20-30% of possible raw materials is mobilized. The high share of (unused) by-product, underlines the importance of production networks and cluster approaches as early as possible in biotechnological process development. Specific challenges to fully exploiting the potential of biogenic residues, including legal and acceptance issues, the need for intelligent biomass decomposition in networked production, and residue availability and management will be discussed.

[1] Mujtaba, M. et al., 2023. https://doi.org/10.1016/j.jclepro.2023.136815

[2] Naegeli de Torres, F. et al., 2023, https://doi.org/10.5281/zenodo.10370137