The chemical characterization of bio-oil components is very challenging due to the complexity of the mixture and the range of physicochemical properties of the components. It is essential to characterize bio-oil components with respect to their major chemical types and functional groups to inform the deoxygenation processing of crude bio-oil surrogates and their viability as an energy source. Due to the range of volatilities of the molecular components, fractionation of the bulk bio-oil can be used to modify the composition so that it contains only components of interest. Here, we investigate aerosolized bio-oil fractions collected onto the different stages of a Microorifice Uniform Deposit Impactor (MOUDI), where fractionation was achieved by aerosol size-segregation and consequently reduced pressures on each of the stages. The molecular characterization of the bio-oil fractions was achieved using ultrahigh performance liquid chromatography equipped with a photodiode array detector and high-resolution mass spectrometry (UHPLC-PDA-HRMS) with both electrospray ionization (ESI) and dopant-assisted atmospheric pressure photoionization (APPI). Through examination of the detected chemical species in each of the separated fractions and assessment of their physiochemical properties, we identify a range of fuel-like aliphatic species with low O/C ratio and low viscosity in the most volatile fraction. The less volatile fractions contained progressively higher portions of more viscous species containing lignin and sugars moieties with characteristic high O/C values. We show that the volatility-based separation of bio-oil and application of complementary ionization techniques facilitate comprehensive characterization of its components with varying fuel viability, capable of informing upgrading processes to improve the design and engineering of novel bio-oil fuels.

Molecular characterization of aerosolized bio-oil

Where thousands of chemistry professionals meet to share ideas and advance scientific and technical knowledge. Spring 2023 abstracts, posters, and presentations will launch at the end of March.

ACS Spring 2023

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.