Ice layer crystallisation (ILC) on a cooling wall is an innovative purification process of freezing proposed to concentrate wastewater. Many works demonstrated the process feasibility but because of pollutant incorporation in ice and low ice yield, its industrial up-scaling was not done. The deadlock status of ILC process could however possibly be circumvented through: i) performing a process intensification study in order to improve its global efficiency; ii) improving process issue that include batch to continuous approach (process efficiency and management).To fulfil this, the WATERSAFE project intends to: i) carry out a comprehensive analysis of local phenomena of the ice crystallization explaining how, why, where and when impurities incorporation takes place in the ice and the ice growth rate in the relation of process parameters by using an approach combining simulation of solidification process and experimental observations; ii) improve the ILC global efficiency by operating the crystallisation on continuous and recycle modes on the liquid phase and by optimising the process parameters.To carry out the first target, WATERSAFE project proposes to develop an innovative dynamic model based on the Phase Field Method (PFM) to simulate the 2D axisymmetric non-isothermal solidification of ice issue from a synthetic wastewater in the ICL process. The PFM is a strong innovative way in the chemical engineering science to model a dynamic system in transition to represent i) the liquid/solid front complex morphology by taking into account ice microstructure; (ii) the pollutant migration in ice; (iii) the solid layer morphogenesis; (iv) the liquid phase hydrodynamics. In literature, solidification process simulation was also proposed to link the morphologic crystallisation phenomena to the operating parameters in order to improve the overall process efficiency. But, the works partially failed because of the simplification of the morphogenesis of interfaces, which is not the case of the PFM method. Indeed, the PFM takes advantage of continuous fields defined in the global system to represent the interfaces and phases. The interfaces dynamic is controlled by the dissipative law of energy defined according the thermodynamic functional of Ginsburg-Landau. The model easily handles time dependent complex geometries, which are typically met in freezing process.In parallel, the WATERSAFE project proposes to design a new lab-scale ILC unit. The process will be enable to operate on continuous and recycling modes on the liquid phase and batch mode on the solid phase. It will be equipped with a high-resolution camera in order to capture the ice layer and front morphologies to perform the crystallisation analysis and complete data. The developed tools allow us combining experimental observations and solidification process simulation to complete the targets. The ILC process development is a major of interest for several industrials applications (pharmaceutical and chemical industries, food processing, electronics and energy industries, micro plastics particles water depollution).

Crystallization is one of the major unit operation to produce, purify or separate solid compounds or products. Whatever the technology, a fine control of the mass and/or heat transfer, i.e. supersaturation, is a key parameter to reach the physical quality of the product (purity, polymorphism, shape, crystal size distribution, specific surface, density...). In a pharmaceutical industrial context, the process chosen for several decades is the batch crystallization by cooling, in a stirred-tank reactor whose capacity is selected according to the needs of the market. A very good control of the polymorphism and the particles size is ensured both at the scale of the hundreds of litters and at the ten cubic meters. On the other hand, antisolvant crystallization processes are difficult to perform at these same industrial scales. In fact, the chemical components mix is unsatisfying and leads to heterogeneous local supersaturation. In addition, the room for improvement regarding the operating parameters is usually low to modulate the physical quality of the active ingredients obtained with this procedure. Purification and grinding steps are often required downstream to obtain the intended specifications of the final product. Therefore, the development of a robust and easily scale-up continuous process, allowing a fine control of the supersaturation, could be of great interest in many industrial areas. MEMCRYST aims to study a revolutionary concept of continuous membrane crystallization process. It is an innovative technology that can be considered because of the increased performance of membranes that could give the French industry a competitive advantage. The project focuses on two modes of supersaturation studied up to the industrial scale: the addition of an antisolvant in a solute/solvent mixture through a porous membrane, thanks to a pressure gradient, which reduces the solubility and induces crystallization; reverse antisolvant, based on pervaporation solvent removing, leads to even lower solubility, thus reducing polymorphic transitions. The mass transfer through the membrane allows a fine control of the supersaturation and therefore a perfect control of the physical quality of the crystals obtained. In addition, the high modularity of membrane processes makes it very interesting for the pharmaceutical industry working in batches of various sizes. The crystallization by antisolvant, and even more by reverse antisolvant, also allows accessing to very low final solubility, thus achieving very high yields and limiting from the risk of polymorphic transitions. A clear improvement in the control of crystallization process requires a technological breakthrough and membrane processes can now be the answer to this issue. In 3 workpackages, the project will focus on different microporous and composite membrane materials in order to study the performance of both processes regarding the physical quality of the product and the industrial feasibility (WP1). The results obtained will be used to enrich and validate the developed models (WP2) that will take into account hydrodynamics and crystallization mechanisms. The objective will be to calculate concentration profiles for a prediction of the crystallization location in the membrane module. Finally, the most industrially promising technology will be developed at a pilot scale (TRL 6-7). The performance of the process (WP3) will be compared to the experimental results obtained at lab scale and to the numerical results. The use will then be extended to the production of molecules of interest.

Green hydrogen can be used as an energy carrier. Stored by hydrogenation in Liquid Organic Hydrogen Carriers (LOHC), its transport becomes safe and the storage capacity exceeds that of liquefied or compressed hydrogen at 700 bars. On request, it can be restored in molecular form by catalytic dehydrogenation, highly endothermic, to power a fuel cell. An alternative and innovative process consists in carrying out, from perhydrodibenzyltoluene as a hydrogen-rich compound, a transfer hydrogenation of acetone, producing dibenzyltoluene and isopropanol, the latter one feeding a direct isopropanol fuel cell (DIPAFC). Both pairs perhydrodibenzyltoluene/dibenzyltoluene and acetone/isopropanol operate in closed-loop while only hydrogen can enter and exit the loop. This process, athermic and safe (no molecular hydrogen is released) could be a significant scientific breakthrough. However, the success of this idea relies on the development of catalysts that perform transfer hydrogenation in a very selective manner, without by-products and deactivation. At the fuel cell level, the choice of electrocatalysts will also drive the selectivity of the electrooxidation of isoproponol, acetone being the only one desired product. Besides, the reactor design is also a key point for the implementation of the concept. A first task will be dedicated to the development of catalysts for the transfer hydrogenation reaction and for the direct isopropanol fuel cell. Minimizing the use of noble metals will be a key point for the catalyst design in both cases, with the use of optimized bimetallic or non noble metal catalysts. The catalysts will be fully characterized and used in the transfer hydrogenation reaction and in the electrochemical oxidation of isopropanol. The former reaction will be first studied in an autoclave at various operating conditions to screen the activity/selectivity of the different catalysts and select the most appropriate one in specific conditions. In parallel, the electrocatalysts will be evaluated for their activity and stability in the electrooxidation of isopropanol with a special care to the selectivity of the oxidation reaction. For both reactions, after the screening phase, further experiments will be performed in (semi)continuous reactors and in fuel cells, respectively. The design of the most appropriate reactors and the feasibility of using this concept in a future integrated process will be evaluated in a final task after thermodynamic and kinetic modeling, thanks to the collection of data from all the experiments. The project gathers 3 academic teams from Lyon, with complementary experience/skills in catalysis, chemical engineering, and electrochemistry which will guarantee the success of the project.

Methodologically, the ODISSE project is at the crossroads of inverse problems for partial differential equations (PDE) and observer theory. These two disciplines have a long and rich history of interactions between them and their overlap is becoming more and more important. The ODISSE project proposes fundamental/theoretical contributions in observer design to reconstitute online missing parameters in some dynamical systems described by PDE. Indeed, to analyze, monitor, control or understand physical or biological phenomena, the first step is to provide a mathematical modeling in the form of mathematical equations that describe the evolution of the system variables. Some of these variables are accessible through measurement and others are not. One of the problems in control engineering is that of designing algorithms to provide real time estimates of the unmeasured data from other measured variables. These estimation algorithms are called state observers and are used in many devices. The implementation of such estimators in the context of hyperbolic PDE systems, which are infinite-dimensional systems in the sense that the system's state belongs to a functional space of infinite dimension, is a topic of great interest both from the practical and theoretical points of view. Systems modeled by hyperbolic PDE, that can be of order one or two, correspond to propagation phenomena and appear in many physical contexts and industrial applications. The ODISSE project aims at developing rigorous methodological tools for the design of estimating algorithms for infinite-dimensional systems governed by hyperbolic PDE, with a particular focus on two typical equations: transport equations (hyperbolic PDE of order one) and wave equations (order two). For this purpose, observability properties of this type of PDE systems will be investigated and novel tools for analyzing their estimations will be developed. Based on the peculiarities of each field, we try several challenges that could help in solving some observation problems for hyperbolic PDEs: 1- Find a way to connect the notion of identifiability in inverse problems and that of observability in observer design. 2- For identifiable parameters in the sense of inverse problems, find a way to synthesize a robust and online estimation algorithm (an observer). 3- Find means to incorporate recent advances in the field of observer designs for nonlinear finite dimensional systems. Conversely, study the possibility of using tools from infinite dimensional systems for observer synthesis for finite dimensional systems. 4- Implement the proposed algorithms and perform convergence analysis of the discretized (finite dimensional) systems toward the continuous initial (infinite dimension) systems. These challenges will be addressed in the ODISSE project through a close collaboration between researchers in applied mathematics and control theory from the community of inverse problems and observers design. Several control applications will serve as a test bed to evaluate practical relevance of the theoretical tools to be developed. More specifically, we will work out analysis and design of observers for the concrete processes : batch crystallization processes, polymerization processes and transient elastography.

The IMPACTS project aims at an ever-increasing integration of modeling, numerics and control design for complex multi-physical implicit systems described by both ordinary and partial differential equations. This integration is achieved considering the novel class of Implicit port Hamiltonian (PH) Systems, analyzing their system properties and developing new dedicated methods for numerical simulation and control design. Implicit PH Systems arise from the modeling of systems with non-local constitutive relations, implicit geometric discretization in time and space or control by interconnection. The methodological contributions of this project will concern the modeling and control of implicit PH systems using irreversible Thermodynamics, geometric numerical methods for space-time discretization and order reduction, canonical implicit discrete-time PH systems and energy-based control design, and in domain/boundary control of distributed parameter systems under implicit interconnections.