BTX from the gas-phase hydrodeoxygenation and transmethylation of guaiacol at room pressure

Abstract

Biosourced aromatics (benzene–toluene–xylene (BTX) and phenols) could be obtained by catalytic hydrodeoxygenation (HDO) coupled with transmethylation at atmospheric pressure in a fixed-bed reactor. We choose guaiacol as a model compound to investigate the catalytic HDO over Fe/Ni/HBeta catalyst. The active amount (5%–15%), temperature (250–400 °C), and 1/WHSV (1.5–4.0) significantly influenced the hydrogenolysis of the CaromaticO bond and transmethylation. The mechanism showed that feed and intermediate products formed the “surface pool” on the catalyst surface, which enabled the HDO reaction by the reduced intermediate species (Z-FeH2+ and Z-NiH+). Fe/Ni/HBeta exhibited good activity for both methyl transfer and HDO. Moreover, the aromatic ring did not undergo catalytic hydrogenation, and most methyl or methoxyl molecules transferred onto the phenolic or benzene ring and remained after deoxygenation. Consequently, carbon loss was minimized, and hydrogen consumption was reduced.