kinetics of the nopol synthesis by the prins reaction over tin impregnated mcm-41 catalyst

the kinetics of the nopol synthesis by prins condensation of β-pinene and paraformaldehyde over sn-mcm-41 synthesized by impregnation was evaluated using the initial reaction rate method. the reaction rate equation obtained from a kinetic model based on the langmuir–hinshelwood formalism with the surface reaction of adsorbed reactants on catalytic sites of the same nature as the limiting step, gave a good prediction of the experimental data. the effect of temperature on the kinetics of nopol synthesis over sn-mcm-41 obtained by impregnation was studied between 75 and 100 °c. the robustness analysis of the kinetic model showed that the surface reaction constant, k^’_sr, should be about 0.185 mol g⁻¹ h⁻¹ at 90 °c, while the ratio between the adsorption equilibrium constant of β-pinene, k_a, and formaldehyde species, k_b, is approximately 1.2:1 (k_a:k_b). the obtained apparent activation energy and pre-exponential factor are 78 kj/mol and 2.3 × 10¹⁰ mol g⁻¹ h⁻¹, respectively, but compensation effect analysis using both experimental and simulated data gave strong evidence of the dependency in temperature of the apparent arrhenius parameters.