A kinetic study of ethanol coupling with acetaldehyde to 1,3-butadiene over Zr-β zeolite: insight into deactivation

BACKGROUND With the improvements in bioethanol production, the process of converting ethanol to 1,3-butadiene (ETB) has received substantial scholarly attention, whose industrialization has been constrained by the stability of the catalysts. RESULTS In this work, the deactivation behavior of Zr- β zeolite in the process of ethanol/acetaldehyde conversion to 1,3-butadiene was investigated. In addition, the deactivation kinetics of ETB was studied using an isothermal differential microreactor. A kinetic model was developed and parametrized with the Langmuir–Hinshelwood mechanism, and the intrinsic kinetic equation was derived. The deactivation kinetic model of the ETB reaction was established from the active site content of the catalyst as a function of time on stream. The validity of the kinetic model was tested, and the results were found to be accurate. CONCLUSIONS Catalyst deactivation was mainly caused by coke species, which are mainly long-chain unsaturated oxygenated organic compounds and aromatic compounds, covering Lewis acid sites in the microporous channels of the catalyst; nevertheless the zeotype topology and morphology were not destroyed. The kinetic data suggested that the reaction was of first order and the activation energy of the deactivation process was 75.59 kJ mol −1 . © 2023 Society of Chemical Industry (SCI).