Upgrading of Lignin-derived Bio-oils: Hydrodeoxygenation Process of Anisole Using Platinum Catalyst

In this research, catalytic hydrodeoxygenation process of anisole derived from lignin is investigated over Pt/Al2O3 catalyst at 573-673 K, 8-14 bar and space velocity of 3-20 (ganisole/gcatalyst*h), in the presence of hydrogen as one of the reactants, using a fixed-bed tubular reactor. The main reaction classes during catalytic conversion of anisole are hydrogenolysis, hydrodeoxygenation, dehydration and transalkylation. During this process, anisole initially converts to phenol through hydrogenolysis reaction. Afterwards, phenol derivatives including: 2-methyl phenol, 2,4-di methyl phenol, 2,3,5,6-tetra methyl phenol are generated via alkylation and trans-alkylation reactions. Benzene is formed through hydrodeoxygenation (HDO) reaction. More over hexa-methylbenzene is formed via alkylation and HDO reactions. Reactions network and kinetic constants are determined using products selectivity and anisole conversion data. According to achieved results, phenol, 2-methyl phenol and benzene are primary products of HDO process. Furthermore, based on kinetic calculations, formation of benzene is not a first-order reaction. Formation of phenol, 2,4,6-tri methyl phenol, 2,6-di methyl phenol, 2-methyl phenol, hexamethyl benzene and 2,3,5,6-tetra methyl phenol are first-order reactions, and the activation energy for their formation are 25.3 kJ/mol, 40.2 kJ/mol, 43.4 kJ/mol, 55.4 kJ/mol, 70.1 kJ/mol and 93.6 kJ/mol respectively.