Hydrodeoxygenation of Bio-Oil Model Compounds in Solvents and Over Carbon-Based Catalyst Using Density Functional Theory

Abstract

In this dissertation, the hydrodeoxygenation of bio-oil model compounds like xylose, dibenzofuran, guaiacol and formic acid is studied in the solvent environment, as well as over carbon-based catalyst using the density functional theory. First, the upgrading of xylose is studied using B3LYP and M06-2X functional to establish a comparison between the two functionals for thermochemistry calculations. For incorporating the solvation effect, an implicit solvation model – SMD, was used. Next, the upgrading of dibenzofuran is studied in the gas phase, in water solvent and in methanol solvent. The reaction scheme converting dibenzofuran to benzene and cyclohexane was proposed and the thermochemistry was calculated for the proposed mechanism. Further, the upgrading of guaiacol is also studies in an implicit water solvent environment to produce benzene, toluene and o-cresol via important intermediates like phenol and anisole. The subsequent chapter highlights the adsorption characteristics of guaiacol and phenol over nitrogen doped graphene. Non-defective and defective graphene sheets were considered for this study, and the adsorption is conducted for different orientations and arrangements of the adsorbate. Finally, the kinetics and thermochemistry of the upgrading of formic acid and guaiacol is studied over β-Mo2C (100) surface to gain insight into the HDO mechanism of carboxylic group and phenols present in the crude bio-oil.