(117c) Conversion of Guaiacol on Noble Metal Catalysts

Catalytic hydrodeoxygenation (HDO) is a rapidly developing technology for oxygen removal from bio-oils obtained from pyrolysis of biomass. In this study, Guaiacol, a phenol derived compound produced by the thermal degradation of lignin, was selected as a model compound to study the HDO process. Guaiacol is among the major components of pyrolysis bio-oils; however it is thermally unstable which leads to catalyst deactivation. Four noble metal catalysts (Pt, Pd, Rh and Ru) supported on activated carbon were tested in a fixed-bed reactor at atmospheric pressure and their performance for the guaiacol HDO process was compared. The screening criteria were as follows: (1) High degree of deoxygenation, (2) Low hydrogen consumption, (3) High carbon recovery in liquid phase, and (4) Long catalyst lifetime. Our results showed that, among the tested catalysts, Pt has higher deoxygenation activity and shows relatively little deactivation. Additionally, the operating temperature for Pt catalyst was optimized and found to be 300 ^oC. Finally, results from catalyst characterization demonstrated that polyaromatic deposits, especially the condensed ring compounds, are the most likely cause for catalyst deactivation. [1]

[1]D. Gao, C. Schweitzer. H. Hwang and A. Varma, Conversion of Guaiacol on Noble Metal Catalysts: Reaction Performance and Deactivation Studies, Ind. Eng. Chem. Res., DOI: 10.1021/ie500495z