Within the framework of a sustainable development in the industrial sector of processing and in particular that of chemistry, this project proposes the development of a miniaturized microwave reactor allowing a safe implementation of any fast chemical reactions at high temperature. Due to its specific design, the system will allow a rapid thermal dynamics due to the microwave heating which is suitable to the energy saving. This system will be tried on a family of chemical reactions concerning the synthesis of quinoline derivatives, molecules of industrial interest in pharmaceutics. Skraup’s reaction will so be implemented in applying some of the principles of green chemistry such as the use of glycerol, the elimination of toxic products… This project requires a multidisciplinary approach involving complementary research groups specialized in the following domains : chemical engineering, microwaves, organic chemistry and materials.

Hydrogen storage in LOHCs (Liquid Organic Hydrogen Carriers) is an alternative to direct storage of compressed or liquefied hydrogen. Numerous studies have been carried out to evaluate the properties of promising pairs of molecules, to synthesise and screen catalysts, and to determine the operating conditions for which the apparent kinetics rates are maximum. The intrinsic reaction kinetics and transport phenomena in the reactors used have been little or not at all published, as well as the behaviour of the reactors used by the solution suppliers. Results on the intrinsic kinetics of hydrogenation and dehydrogenation of LOHCs and on the quantification of the mass and heat transfer limitations in the used reactors would however make it possible to find solutions to overcome the bottlenecks to the development of industrial reactors and to evaluate the industrial hydrogenation processes already in existence. The RID-LOHC project therefore proposes to work on the hydrogen storage with carbazole mixtures and with commercial catalysts. It aims to acquire knowledge on the intrinsic kinetics of hydrogenation and dehydrogenation and on the stability of the molecules and catalysts. It also aims to evaluate the relevance of the use of conventional continuous three-phase reactors in hydrogenation (fixed beds in particular) and to design, manufacture, characterise new efficient reactors, as well as to evaluate their performance in terms of heat and material transfer for hydrogenation and dehydrogenation, of sustainability and safety. The considered approach will take advantage of a synergy between experimental and numerical methods.

The relationships between the structure of chemicals (reactants or products) and their reactivity (kinetics and thermodynamics) is a research area that crosslinks thermodynamics, kinetics, organic chemistry and chemical engineering. This project will investigate this research area by German and French specialists. The concept of Linear Free Energy Relationships (LFER), including Taft equation, is a powerful structure-reactivity tool that accounts for steric, polar and resonance effects on a series of chemical reactions. Taft equation shows that there is a relationship between the structure of reactants (i.e., the substituent near to the reaction center) and their reactivities within a reaction series. It is state-of-the art to apply this to chemical reactions (e.g. esterification), and it is claimed that the developed parameters are valid independent of the reaction conditions. However, mainly esterification and hydrolysis reactions were used in one kind of solvent, which in principle limits the general validity of the relationships. Thus, generalizing LFER concepts to vast number of solvents or solvent mixtures and even to multiphase reaction systems requires intrinsic kinetic profiles in the absence of concentration and temperature gradients, expressed in terms of thermodynamic activities. This will be developed in this project. The redeveloped Taft-based method will be mainly applied to three chemical reaction systems that involve lignocellulosic-derived platform molecules: 1) glucose solvolysis to levulinate ester using different alcohol solvents, 2) esterification-hydrolysis of levulinic acid-levulinate ester and 3) hydrogenation of levulinic acid or levulinate ester to gamma-valerolactone by H2 and solid catalyst. For these systems, we will vary the reactants, i.e., different alcohols for 1) and 2), and different levulinate esters for 3). System 2) will prove the validity of the LFER concept to enzyme catalysis. The goal is to use the redeveloped method to study and predict the -R substituent effect in the reactant and the solvent effect on kinetic profiles. Reaching the goal requires different research expertise. The use of microfluidic technologies will allow performing kinetic experiments avoiding transport limitations. Activities of the reactants and products will be predicted based on the experimental kinetic profiles and the equation of state ‘ePC-SAFT’. This will ultimately allow predicting reaction properties (standard enthalpies, standard Gibbs energies) as well as intrinsic activity-based reaction kinetic constants. Furthermore, ePC SAFT will be used to predict the required phase behavior of the reaction systems (e.g. H2 solubility in reaction medium); all predictions (phase behavior and reaction characteristics) will be validated by experiments. The association of both methods –LFER & ePC-SAFT– will mean a significant new understanding and a new dimension in designing chemical syntheses.

The ASPI project is mainly motivated by the development of an added value system engineering concerning the control problem of intensified chemical processes. These issues range from the control system design to its supervision with a particular emphasis on those fundamental functions regarding the diagnosis, the prognosis as well as predictive maintenance. Supervision will be elaborated from the best available results on fault diagnosis and identification, observer’s synthesis, system identification, faults tolerant control and efficient procedures for signal processing. These methodologies will allow man to be unloaded from a part of the process monitoring while increasing the operational safety. For this, it will be necessary to anticipate and correct any drifts or dysfunctions that could lead to accidental situations. These techniques will be applied to an industrial field that is particularly critical from the point of view of safety and the catastrophic consequences that accidents can cause: chemistry and more specifically fine chemistry, pharmaceutical chemistry and new syntheses for the valorization of biomass. Another aspect of the project concerns the transformation of production processes through the implementation of innovative processes in the field of process intensification that prefigure the chemical plant of the future. In the production line, the reactor occupies a central place because chemical reactions occur in it. Reactions are highly non-linear operations with respect to the different operating conditions and whose control is crucial in relation to productivity and safety. In the project, we will focus more specifically on new types of multifunctional, continuous reactors that are an alternative to traditional 'batch' reactors. These intensified reactors radically improve the transport and transfer properties (thermal and mass) and allow implementing reactions by approaching the intrinsic limits of their kinetics. This interdisciplinary fundamental and methodological research work will be performed in collaboration between laboratories of Chemiacl Engineering and Automatic: LGC, LAAS, LAC and LSPC. Fundamentally, this involves the development of experimental modeling, observer synthesis, identification and error detection and fault-tolerant control approaches for intensified reactors. These approaches will be particularly used to develop a control system with a predictive ability to anticipate accidental situations. From chemical engineering point of view, the control system must guarantee the operational safety of the intensified processes. Particular attention will be paid to the development of a realistic simulator of static and dynamic behaviors and the creation of a fault database for the supervision of the control system and its reconfiguration if necessary. This requires good modeling of reactors in degraded mode with management of model changes in case of fault detection. Experimental validations will be carried out on pilots available in laboratories to highlight the added value of the developed approaches. Two situations will be addressed: an implementation in a case already studied both from the point of view of the apparatus and the chemical system and the generalization to a system (reactor and chemical synthesis) for which the characterization is still incomplete.

Biomass process valorization is increasing, and using hydrogen or oxygen is vital to ensure the success of these processes. Nevertheless, biorefinery, and more generally processes valorizing biomass, are not inherently safer than the petro-based equivalent. COGNAC will train the next generation of process safety researchers in theoretical sciences (DFT), engineering sciences (CFD, process analysis), experimental analysis (calorimeter), social perception and multicriteria process analysis. COGNAC’s PhD student will make excellent science in the 20’s and be leader in the field of safety in 30’s. With the increased biomass processes, our project is in the right time. The initial events provoking a chemical accident are fire, leakage, explosion, or thermal runaway. Studies from Dakkoune et al. highlighted that around 25% of the accidents in chemical plants are caused by thermal runaway. Therefore, this event is still considered the main threat in the chemical industry. Thermal runaway can be defined as a rapid, uncontrolled rise in temperature during a chemical reaction; and occurs in non-isothermal mode. The possible consequences of thermal runaway are the reactor's destruction (overpressure) and/or projection of fragments. From several studies, operator errors are the main cause of thermal runaway. As Prof. Kletz pointed out, saying that thermal runaway is due to human error is like saying that falls are due to gravity; it is true but not helpful. Research must focus on predicting, detecting and mitigating a thermal runaway situation. The mitigation of a runaway depends strongly on the accuracy and precision of the detection system and on the knowledge of the chemical system (e.g. sizing the relief vent). There are two fundamental conditions for an efficient detection system: it must identify real thermal runaway (not a false alarm) and detect this situation as earlier as possible. The use of biomass materials as raw materials in chemical industry is increasing. There are several motivations for this shift: increase the independence towards fossil-raw material countries, use of renewable raw materials, favour CO2 neutrality, etc. Are these processes technologically safer, less toxic, environmental friendly and cost-competitive? These questions could be solved without human and social science experts, but what is citizen perception towards these processes? requires Human and Social Sciences expert experts. From a technological risk aspect, researchers from COGNAC consortium shows that biomass valorization processes present some risk of thermal runaway, dust explosion, etc. COGNAC proposes to work at the cutting edge of our knowledge in the field of thermal runway and dust explosion prediction-detection-and-mitigation in biomass processes. COGNAC will particularly study the hydrogenation and oxidation of 5-alkoxymethylfurfural and levulinate, that are issued from the valorization of cellulose and hemicellulose, respectively.