Etude de la désactivation de la réaction de déshydrogénation de l’éthanol

Catalyst deactivation is the loss of catalytic activity and/or selectivity with time. This is a major and recurring problem in industrial-scale processes. Catalyst deactivation is unavoidable and has a major impact on the reactor technology used and therefore on the process design. Nevertheless, some effects related to deactivation can be avoided, reduced or even reversed. Deactivation is therefore linked to process industrial operation, and is a key phenomenon for the design, the development of any chemical process. The deactivation phenomena depend on catalyst, reactional system, operating conditions and reactor technology and/or scale. Without industrial data, deactivation can be investigated at laboratory scale through a specific an experimental strategy that reveals the different mechanisms. To do so, it is crucial to have characterization methods dedicated to assessing the evolution of catalyst textural properties over time. Deactivation can also be investigated by different modeling approaches. The objective of this thesis is to study the catalyst deactivation for the dehydrogenation reaction of ethanol. The dehydrogenation of alcohols is a major issue at IFPEN. This reaction consists of the first step of a butadiene production process from bio-based ethanol. The different deactivation phenomena will be experimentally investigated and then included in a mechanistic model. This latter will combine reactions between molecules and sites, inter-site reactions and reactions dealing with coke formation and deposition. This model will be used and adapted to predict the evolution of the apparent deactivation kinetics observed with reactor size variation.