Analysis of Risks Associated with Hazardous Materials Transportation in the French Chemical Industry

This article focuses on the risks associated with Hazardous Materials Transportation (HazMaT) events in the French chemical industry between 1981 and 2022. The study aims to analyze and assess the causes and consequences of past events using the ARIA database, which lists over 54,000 events that have taken place in France and abroad. The severity of events is classified into five categories, from near misses to catastrophic events. The study highlights the importance of risk analysis/assessment and lessons learned from past events in managing natural and technological risks

Alternative method to prevent thermal runaway in case of error on operating conditions continuous reactor

International audienc

Mass & energy balances coupling in chemical reactors for a better understanding of thermal safety

International audienc

From calorimetry to thermal risk assessment: γ-Valerolactone production from the hydrogenation of alkyl levulinates

International audienceThe use of lignocellulosic biomass as a raw material can sustain the chemical industry. There is a lack of knowledge in kinetics and thermodynamics of some of these processes, making difficult the cost analysis. For instance, the thermodynamic investigation of the hydrogenation of alkyl levulinates to γ-valerolactone (GVL) is seldom. This system is a two-step reaction comprising a hydrogenation and cyclization step. The experimental measurement of the two reaction enthalpies is challenging, and a method was developed in this manuscript. The hydrogenation of methyl levulinate (ML) and butyl levulinate (BL) in the GVL solvent was found to be an exothermic step, and the cyclization an endothermic one. The reaction enthalpy for the hydrogenation of ML in the GVL solvent, calculated to -53.25 kJ/mol, is higher than the one of BL in the GVL solvent, calculated to -38.66 kJ/mol. The reaction enthalpies for the cyclization step are similar for ML and BL system, i.e., +7.00 kJ/mol and +6.50 kJ/mol, respectively. Hence, the hydrogenation step governs the reaction temperature. A thermal risk assessment based on experiments performed under adiabatic condition was done. The thermal risk was found to be medium for this reaction system under the operating conditions used in this study

Early detection and diagnosis of thermal runaway reactions using model-based approaches in batch reactors

International audienc

Analysis of thermal runaway events in French chemical industry

International audienc

Risk analysis of French chemical industry

International audienc

Étude comparée pour la détermination de paramètres cinétiques de pyrolyse de biomasse par analyse thermogravimétrique

International audienceThis paper discusses the different methods for determining the kinetic parameters (activation energy and pre-exponential factor) of biomass (beechwood and flax shives) pyrolysis based on Kissinger method, isoconversional methods (Kissinger–Akahira–Sunose and Friedman) and based model (nonlinear least square minimization and optimization by genetic algorithm). Because of the widely dispersed values of activation energy and pre-exponential factor of three pseudo-components of the biomass (cellulose, hemicellulose and lignin) found in the literature, thepyrolysis of cellulose, hemicellulose and lignin was also studied. This paper shows that kinetic parameters are very sensitive to methods used. The comparison of results shows a large difference for the same experimental results even for pure pseudo-components. Based on results comparison, we think that Kissinger method remains the best method for kinetic parameters determination. Indeed, Kissinger relation takes into account the biomass structure effect and the mineral content. Isoconversional methods are also very suitable for low and medium conversion rate. Despite the fact that based methods are considered to be robust methods for the estimation of kinetic parameters in chemicalCe document traite différentes méthodes de déterminer les paramètres cinétiques (énergie d'activation et facteur pré-exponentiel) de la pyrolyse de la biomasse (bois de hêtre et lin) basée sur les méthodes de Kissinger, isoconvertionnelles (Kissinger – Akahira – Sunose et Friedman) et une basée sur un modèle (minimisation non linéaire des moindres carrés et estimation par algorithme génétique). En raison de la forte dispersion des valeurs de l'énergie d'activation et du facteur pré-exponentiel des trois pseudo-composés de la biomasse (cellulose, hémicellulose et lignine) trouvés dans la littérature, la pyrolyse de la cellulose, de l’hémicellulose et de la lignine a également été étudié. Cet article montre que les paramètres cinétiques sont très sensibles aux méthodes utilisées. La comparaison des résultats montre une grande différence pour les mêmes résultats expérimentaux, même pour les pseudo-composants purs. En se basant sur la comparaison des résultats, nous pensons que la méthode Kissinger reste la meilleure méthode pour la détermination des paramètres cinétiques. En effet, la relation de Kissinger prend en compte l’effet de la structure de la biomasse et la teneur en minéraux. Les méthodes d’isoconversion sont également très adéquates pour les taux de conversion bas et moyen. Malgré le fait que les méthodes basées sur un modèle sont considérées comme des méthodes robustes pour l'estimation des paramètres cinétiques en génie chimique, ces méthodes peuvent mal estimer l'énergie d’activation et le facteur pré-exponentiel pour la cellulose, l’hémicellulose et la lignine

Zero-Order Versus Intrinsic Kinetics for the Determination of the Time to Maximum Rate under Adiabatic Conditions (TMR ad ): Application to the Decomposition of Hydrogen Peroxide

International audienc

Application of the concept of Linear Free Energy Relationships to the hydrogenation of levulinic acid and its corresponding esters

International audienceBiomass valorization to chemicals, biofuels or materials will be more and more important during this century. Production of γ-valerolactone (GVL) from the hydrogenation of levulinic acid is a good illustration of this tendency. GVL can also be produced from alkyl levulinates hydrogenation. Can we find a relationship between the structure and the kinetics of this reaction? Can we predict the kinetics of any alkyl levulinates by knowing the kinetics of another alkyl levulinate? This paper has studied these two questions by developing a kinetic model including the effect of gas-liquid mass transfer. We have demonstrated that the kinetics of hydrogenation of levulinic acid, methyl, ethyl and butyl levulinates to GVL using Ru/C follow the Taft equation, which is derived from Linear Free Energy Relationships. This equation measures the effects of polar and steric on a reaction series. We have demonstrated that polar effect of the reaction series is the most significant effect. This relationship can predict the values of kinetic constants just by knowing their structure