Mild and tunable pyrolytic lignin ozonolysis in acetic acid

PALAZZOLO, M. A.; EUVERINK, G. J. W.; HEERES, H. J.; DEUSS, P. J.

Conferencia; CA17128 LignoCOST Lignin Conference; 2022

CA17128 LignoCOST Lignin ConferenceMild and tunable pyrolytic lignin ozonolysis in aceticacidDr. Martin A. Palazzolo1,2,Prof. Dr. Hero J. Heeres1, and Prof. Dr. Peter J. Deuss11 Department of Chemical Engineering, ENTEG, Universityof Groningen, Nijenborgh 4, 9747 AG, Groningen, the Netherlands2 Instituto de Investigaciones en Tecnología Química(INTEQUI), FQByF, Universidad Nacional de San Luis, CONICET, Almirante Brown1455, 5700, San Luis, Argentinam.a.palazzolo@rug.nl Biorefineries must offerorganic compounds of greater market value to be economically viable. Microbialcells are attractive tools to transform complex carbon macromolecules fromcheap, renewable waste streams into simpler organic molecules with highervalue. Although the bioprocessing of cellulose and hemicellulose is wellestablished, the microbial conversion of the lignin fraction still remains asthe bottleneck for the full biotechnological valorization of biomass.Therefore, the development of efficient technologies to make easier thefunneling of lignin carbon into microbial cell factories is the current goal inmany biorefinery projects. Our group has reported the successful application ofozonolysis of different lignins as a tool for processing. This yielded theformation low molecular weight (di)acids and esters, along with larger highlyoxygenated aliphatics, by using short-chain alcohols like methanol[i]and ethanol[ii] assolvents, which was proven to be a great pretreatment step for furtherprocessing (e.g., by catalytic hydrogenolysis). Herein, we describe preliminaryreaction conditions for the ozonolysis of pyrolytic lignin in acetic acid thatare not only milder but also tunable. Mixtures of lower oligomer content and aseries of readily-fermentable phenolic monomers can be obtained on demand. Moreover,the solvent, acetic acid, can be recovered in high yield and quality to bereused in new lignin ozonolysis reactions or in subsequent fermentations.Acknowledgements: Thiswork was supported by the OPCW Fellowship Programme. The views expressed inthis report are those of the author and not those of either the OPCW or theauthorities of the country or countries whose facilities were made availablefor the Fellowship.[i] Figueirêdo,M. B., Deuss, P. J., Venderbosch, R. H., & Heeres, H. J. (2019). Valorization of pyrolysis liquids: ozonation of the pyrolytic ligninfraction and model components. ACS Sustainable Chemistry &Engineering, 7(5), 4755-4765.[ii] Figueirêdo, M. B., Heeres, H. J., & Deuss, P. J.(2020). Ozone mediated depolymerization and solvolysis of technical ligninsunder ambient conditions in ethanol. Sustainable Energy & Fuels, 4(1),265-276.