| Biofuels have gained significant attention as the most promising alternative energy and fuel supply for the near future because of two dominant reasons: first, biofuels are environmentally friendly; and second, they afford a sustainable technology. Biofuels can be synthesized from biomass by several different processes, among which, hydrothermal conversion is considered to be more energy efficient. However, scientific efforts to improve hydrothermal biomass-to-fuel (HT-BTF) conversion efficiencies are severely limited because little is known about the salient reaction mechanisms and intermediates. This study is aimed at a better understanding of the hydrothermal biomass degradation kinetics by advanced NMR spectroscopy and, accordingly, is a significant contribution to find new, efficient and sustainable ways to produce synthetic fuels. A far-reaching impact is anticipated for the development of biomass treatment plants and for related research work conducted nationally and internationally.;In HT-BTF conversion, water is both the solvent and the product, and the quantitative NMR analysis of solutes was hampered by the presence of the strong water signals. In this work, the Exponentially Converging Eradication Pulse Train (EXCEPT) sequence for solvent suppression is introduced, which is found to be extremely tolerant to samples with varying relaxation times. This advanced NMR spectroscopy method was used to characterize intermediates and products, elucidate kinetics, and optimize yields of high-value products. 5-hydroxymethylfurfural, 4-oxopentanoic acid and formic acid were found to form as products during the hydrothermal reaction of D-glucose (a model substrate for cellulosic biomass). It was also found that formic, acetic, and lactic acids as well as methane gas were formed as by-products. |
