The Air Quality Impacts of the Bio-Based Solvent Cyrene

Solvents have long been recognized as one of the principal sources of waste from the chemical industry, particularly from fine chemical manufacturing.^1,2 While neoteric solvents with minimal atmospheric impact such as supercritical fluids and ionic liquids show promise for some applications, most processes remain dependent on organic solvents. As a result, the last two decades have seen a rapid increase in the development and deployment of bio-derived and biodegradable “green” solvents.³ Design processes for such solvents pay close attention to solvent performance, human and environmental toxicity, and process-scale safety, however the impact of new “green” solvents on the chemistry of the atmosphere remains largely unexplored. As increasingly strict  regulation brings traditional sources of VOC emissions under control solvents have emerged as the largest anthropogenic source of non-methane VOCs.⁴ It is therefore crucial that we expand our understanding of the atmospheric ramifications of this growing and diversifying class of emissions.

This work is a collaboration between green materials chemists and atmospheric scientists. Our interdisciplinary approach to solvent selection and development involves rigorous experimental and in silico testing of both solvent performance and environmental impact as VOCs. Herin we will discuss the atmospheric chemistry of the bio-derived solvent Cyrene (dihydrolevoglucosenone, C₆H₈O₃). Our investigation into this unique, bicyclic multifunctional oxygenate covers its two primary atmospheric breakdown routes. Chamber experiments to determine OH kinetics and aerosol yields, quasi-gas-phase measurement of UV cross sections and fast flow investigations into photolysis quantum yields. Results will be presented in the context of Structure-Activity Relationship (SAR) calculations and other predictive tools, with impacts assessed via estimations of atmospheric lifetime and photochemical ozone creation potential. 

The chamber experiments carried out as part of this work are part of a Transnational access project that is supported by the European Commission under the Horizon 2020 – Research and Innovation Framework Programme, H2020-INFRAIA-2020-1, ATMO-ACCESS Grant Agreement number: 101008004

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(2)          Bryan, M. C.; Dunn, P. J.; Entwistle, D.; Gallou, F.; Koenig, S. G.; Hayler, J. D.; Hickey, M. R.; Hughes, S.; Kopach, M. E.; Moine, G.; Richardson, P.; Roschangar, F.; Steven, A.; Weiberth, F. J. Key Green Chemistry Research Areas from a Pharmaceutical Manufacturers’ Perspective Revisited. Green Chem. 2018, 20 (22), 5082–5103. https://doi.org/10.1039/C8GC01276H.

(3)          Jordan, A.; Hall, C. G. J.; Thorp, L. R.; Sneddon, H. F. Replacement of Less-Preferred Dipolar Aprotic and Ethereal Solvents in Synthetic Organic Chemistry with More Sustainable Alternatives. Chem. Rev. 2022, 122 (6), 6749–6794. https://doi.org/10.1021/acs.chemrev.1c00672.

(4)          Lewis, A. C.; Hopkins, J. R.; Carslaw, D. C.; Hamilton, J. F.; Nelson, B. S.; Stewart, G.; Dernie, J.; Passant, N.; Murrells, T. An Increasing Role for Solvent Emissions and Implications for Future Measurements of Volatile Organic Compounds. Philos. Trans. R. Soc. Math. Phys. Eng. Sci. 2020, 378 (2183), 20190328. https://doi.org/10.1098/rsta.2019.0328.