Refinement of the kinetic model for guaiacol hydrodeoxygenation over platinum catalysts

Abstract

AbstractIn our prior work (Ind Eng Chem Res, 2015, 54, 10638‐10644), hydrodeoxygenation (HDO) kinetics of guaiacol, a well‐known model compound of bio‐oil, over Pt/AC (activated carbon) catalysts were investigated under integral operating conditions. It was found that the pseudo‐homogeneous plug‐flow model utilizing these kinetics describes the experimental observations well (with normalized RMS error = 7.6%). In the present work, under differential operating conditions instead, we refine the kinetic model for the same reaction network over the same catalyst. We show that among the five reaction steps in the network, the reaction order of one step differs from our prior work, while the orders remain unchanged for the other four steps. The activation energies of two steps differ from our prior values by 10–15 kJ/mol, and for the other three steps remain essentially consistent with our prior work. The kinetic parameters from the present work are used to predict fixed‐bed reactor performance under integral operating conditions as well. The comparison between experimental and predicted values for both the prior and new sets of data is excellent and even better than our prior model (with reduced normalized RMS error = 4.2%). The kinetic analysis additionally proposed that the direct and indirect pathways of phenol formation from guaiacol HDO depend on guaiacol conversion values. The present work demonstrates that kinetic expressions and parameters obtained from a gradientless differential reactor are more reliable and can be used to successfully predict integral reactor performance data.