Kinetics Study on Oxidation of β-Isophorone Using Molecular Oxygen

Abstract

The oxidation kinetics of β-isophorone (β-IP) using molecular oxygen catalyzed by iron(III) acetylacetonate was investigated in a lab-scale agitator bubbling reactor. β-IP was found to give keto-isophorone (KIP) and 4-hydroxy-3,5,5-trimethyl-2-cyclohexen-1-one (HIP) along with little isomerization product α-isophorone (α-IP). The results show that the oxidation reaction took place in the pseudo–first-order fast reaction regime. The experiment was conducted under the mass transfer reaction regime as the mass transfer resistances could not be easily eliminated. The intrinsic kinetics was obtained through apparent kinetics. The activation energy of oxidation of β-IP to KIP is 70.5 ± 4.1 kJ mol–1, and the value of ln AKIP is 33.53 ± 1.22. Meanwhile, the activation energy of oxidation of β-IP to HIP is 86.4 ± 5.4 kJ mol–1 and the value of ln AHIP is 36.23 ± 1.52, which could provide theoretical basis for industrial design, amplification of reactor, and the optimization of reaction.