Application of pure shift and diffusion NMR for the characterisation of crude and processed pyrolysis oil

Abstract

By combining diffusion-ordered NMR spectroscopy (DOSY) and pure shift NMR spectroscopy ((Pure Shift Yielded By Chirp Excitation (PSYCHE)) with 1D NMR metabolite assignment, we demonstrate an improved method for in situ analysis of pre and post-processed pyrolysis oil to quickly establish the most effective upgrading procedure. These experiments use molecular mass estimations from DOSY and single component verification using PSYCHE to confirm the identity of metabolites and show how the mass pattern for pyrolysis oils varies depending on how it is upgraded.With the use of a semi-automatic approach for metabolite assignment, we have verified and quantified individual components, giving rise to a collection of potential ‘marker compounds’; their changes in concentration being correlated to the upgrading process a pyrolysis oil undergoes.