Dr Diana Palacio Lozano, Leverhulme Trust Early Career Fellowship
Towards Greener Biofuels: A new Method to Reveal Structural Insights into Bio-Oils
Renewable fuels are expected to play an important role in the decarbonisation of the transport sector, such as ships and planes, where electrification is difficult or impractical.
Despite their potential, pure renewable fuels are rarely used as fuel. Instead, low percentages of biofuels (e.g. 5%) are blended with petroleum-derived fuels. The use of higher percentage blends is less common due to factors including vehicle modifications, consumer acceptance and production-refining costs. A primary limitation for bio-oil production is the poor understanding of their complex chemical nature. Existing characterisation techniques certainly do not reveal the whole picture of the composition of complex mixtures. Ultrahigh-resolution mass spectrometry (UHRMS) experiments, for instance, allow the determination of individual molecular compositions
Dark matter
There is, however, an unknown level of “dark matter” that cannot be detected as a consequence of experimental parameters and sample complexity.
The uncertainty greatly increases when the structure elucidation is considered. It is well-known that molecules of the same composition can be found in different bonding arrangements (isomers).
Each isomer corresponds to a distinctive chemical with unique properties. It is estimated that there are a larger number of isomeric compositions just containing carbon, hydrogen and oxygen atoms than stars in the observable universe (1046 to 1021)! Therefore, the structural elucidation of complex mixtures is the “holy grail” for energy and environmental research.
Figure 1: Functionality screening of complex mixtures.
Bruker solariX 12T FT-ICR MS system located at the Ion Cyclotron Resonance Laboratory at the University of Warwick.
Revealing the fine print of the chemistry in complex mixtures
Given the complexity of bio-oils, gaining structural insights for individual molecules in complex mixtures is currently challenging. Dr Diana Palacio Lozano's Fellowship explores the potential of an alternative method to reveal the fine print of the chemistry in complex mixtures.
Diana is interested in identifying the molecules that contain certain functional groups, such as aldehydes (that are generally unstable and react over time) and can perform chemical reactions to target those specific functionalities based on their reactivity (chemical derivatization).
A comparison of the compositions before and after derivatization will reveal the highly reactive chemical entities, and therefore, those entities are more likely to contain the targeted functional group.
Due to sample complexity, coupling of chromatographic techniques to UHRMS is required for this method, as it enables the isomeric separation required while detecting thousands of co-eluting species. Diana believes the derivatization-separation-resolution method shown in Figure 1 [above] can pave the way for advanced refining approaches and the optimisation of bio-oil quality.