The increasing burden of climate change and resource depletion is leading society to rethink our largely fossil-based chemical industry. Given that most of our chemicals are made from carbon, renewable solutions are likely to come from the only two large sources of renewable carbon on the planet: atmospheric carbon dioxide and plants. However, technologies to convert carbon dioxide are still far from practical, while the lack of cost-competitive solutions has limited the implementation of plant-based products. New breakthrough methods to valorize molecules from natural materials, such as wood or plants in general, will therefore play a central role in promoting the switch to bio-based feedstocks.
In terrestrial plants, "lignin" - the second largest biopolymer on earth after cellulose and the largest natural source of aromatic molecules - has evolved to provide a range of functions to the plant. Beyond its main function, which is to provide structural cohesion to counter gravity, lignin protects the plant cell from environmental stresses, such as UV light, bacterial and fungal contamination or oxidative agents. These properties are given by well-defined bioactive internal structural motifs, that only have only recently begun to be understood and that could potentially hold tremendous value for the pharmaceutical industry.
Yet today, there are no industrial methods able to extract these naturally occurring molecules. The reason is that lignin is a very reactive polymer that has a strong propensity to aggregate (condense), making the isolation of those structural motifs impossible. The Laboratory of Catalytic and Sustainable Processing (LPDC) has recently developed and scaled the ground-breaking Aldehyde-Assisted Fractionation method (AAF) that prevents undesired aggregation reactions of the polymer, opening the door to the first large scale production of these bio-active molecules.
The present project will investigate the selective depolymerisation of lignin into bio-active motifs and characterize the composition of the products. Partners will support this work with piloting facilities and using various depolymerisation methods. Overall, the endeavour aims at developing the first cost-competitive biorefining concept able to serve a range of confirmed markets, including fragrances, cosmetics, micro-fibrillated cellulose as well as the nutraceutical and pharmaceutical industries. The successful identification and production of bio-active molecules will have a game-changing impact on the process cost-competitiveness and allow much smaller production units to be commercially viable, thereby significantly reducing the time to market for biorefining technologies such as AAF.
What is special about the project?
The project has the potential to disrupt the viability of current biorefinery concepts. Given the importance of sustainable, fossil-free materials going forward, it is of foremost importance to develop processes that gain rapid market acceptance. This is only possible if the prices are matching current petroleum-derived products. The Intellectual Property in high-value applications, such as bioactive molecules, aims at strengthening the techno-economics of the current process and accelerate market entry. Furthermore, Series A investment will be more attractive if high returns generated by bioactive molecules can be confirmed.
The Aldehyde-Assisted Fractionation (AAF) process has already been performed at a kg scale in our pilot facility, and the performances are unprecedented. The main advantage is that - for the first time - some natural structures from biomass can be maintained during the extraction process, opening countless doors for the production of new sustainable chemicals and materials. Accordingly, 5 kgs of uncondensed lignin fraction, a rich aromatic biopolymer, were obtained so far. Furthermore, Bloom has recently increased the reactor capacity of the AAF biomass pretreatment from 50 L to 250 L, with the ultimate goal of producing 5 kg of lignin per batch.
In a subsequent depolymerization step, the obtained lignin is converted into valuable compounds with potential bioactivity. More than 1 kg of lignin have been depolymerized under various screening conditions, and a scale-up of this step in 2021 (from 1 L to 20 L) will allow the depolymerization of 1 kg of lignin per batch. The downstream processing of the product oils from lignin depolymerization is our current focus to efficiently isolate bioactive compounds. Different separation technologies are being assessed, such as liquid-liquid extraction, distillation, precipitation and ultrafiltration. The ongoing downstream processing activities progress hand-in-hand with the development of an appropriate toolbox to characterize and quantify the molecules of interest. This includes analytical techniques such as gel permeation chromatography (GPC), gas chromatography (GC-FID, GC-MS), silylation, acetylation, nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HRMS). A portfolio containing the main obtained compounds is under construction, and the bioactivity of these materials will be further explored. Indeed, plants have evolved a lot of structures (particularly within the lignin fraction) to protect themselves against environmental stresses, should it be UV light, oxidative stress or defense against microbes. In this project, these activities will be assessed for AAF-lignin materials in order to develop high-value applications, such as cosmetics, fertilizers, pesticides or pharmaceuticals.
EPFL has granted an exclusive license to the technology to Bloom Biorenewables SA, a spin-off created by employees of the laboratory. Over the past two years, Bloom established a strong network of academic and industrial partners in Switzerland and across Europe to develop new bio-based applications. Overall, the team raised CHF 3.9M, mainly from non-dilutive R&D and technology transfer grants. A successful outcome of this project will contribute to Bloom’s ambition to build a demonstration unit in Q2 2022.
YM Questell-Santiago, MV Galkin, K Barta, JS Luterbacher, Nature Reviews Chemistry, 2020, Stabilization strategies in biomass depolymerization using chemical functionalization;
S Bertella, JS Luterbacher Trends in Chemistry, CellPress, 2020, Lignin Functionalization for the Production of Novel Materials;
MT Amiri, GR Dick, YM Questell-Santiago, JS Luterbacher Nature protocols 14 (3), 921-954, 2019 Fractionation of lignocellulosic biomass to produce uncondensed aldehyde-stabilized lignin;
W Lan, JB de Bueren, JS Luterbacher Angewandte Chemie International Edition 58 (9), 2649-2654, 2019, Highly Selective Oxidation and Depolymerization of , Diol Protected Lignin;
F. Héroguel, X. T. Nguyen, J. S. Luterbacher. ACS Sustainable Chem. Eng. 2019, 7, 16952 16958. Catalyst Support and Solvent Effects during Lignin Depolymerization and Hydrodeoxygenation;
J Behaghel de Bueren, F Héroguel, C Wegmann, GR Dick, R Buser, and JS Luterbacher, ACS Sustainable Chem. Eng. 2020, 8, 45, 16737–16745 Aldehyde-Assisted Fractionation Enhances Lignin Valorization in Endocarp Waste Biomass;
R Vendamme, J Behaghel de Bueren, J Gracia-Vitoria, F Isnard, MM Mulunda, P Ortiz, M Wadekar, K Vanbroekhoven, C Wegmann, R Buser, F Héroguel, JS Luterbacher, W Eevers, Biomacromolecules 21 (10), 4135-4148, 2020 Aldehyde-Assisted Lignocellulose Fractionation Provides Unique Lignin Oligomers for the Design of Tunable Polyurethane Bioresins.
Persons involved in the project
Last update to this project presentation 07.07.2022