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

Abstract

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).

Simultaneous Mesoporosity Generation and Lewis Acidity Enhancement in Zr‐Based Metallosilicalite for Promoting the Conversion of Ethanol‐Acetaldehyde to 1,3‐Butadiene

“…Our group has investigated the deactivation behavior of Zr-β zeolite in ETB, giving the kinetics under deactivation, where it can be concluded that the deactivation is due to the coke coverage on the Zr sites, not blocking the microporous channel. [33] Thus developing hierarchical porosity in the zeolite matrix is a simple and efficient way for catalytic performance improvement. For example our group has developed several strategies to develop hierarchical porosity in Zr-β zeolite, including surfactant-templating, [34] protective desilication, [35] dual-template, [36] bifunctional template synthesis, [37] and IDRC.…”