Hydrodeoxygenation of 4-Propylguaiacol (2-Methoxy-4-propylphenol) in a Microreactor: Performance and Kinetic Studies

Catalytic hydrodeoxygenation of 4-propylguaiacol, a model compound for lignin-derived components of pyrolysis oil, was performed in a packed-bed microreactor. The effects of various processing conditions were investigated using presulfided NiMo/Al2O3 catalyst. The conversion of 4-propylguaiacol is highly influenced by temperature. Although many products were formed, 4-propylphenol predominated under the operating conditions selected with presulfided NiMo catalyst. External and internal mass-transfer resistances and heat-transfer resistance were investigated and found to be negligible. Reaction rate expressions were based on proposed reaction mechanisms using the Langmuir-Hinshelwood approach. Nonlinear regression was performed to obtain kinetic constants. The best-fitting rate equations were further validated by comparing experimental data obtained from an integral reactor with predictions obtained using the Runge-Kutta method based on the rate equations. A difference of less than 10% between the experimental data and the predicted data for the integral reactor was found.