Développement, conception et mise au point d’un procédé de purification du bio-acide acrylique par cristallisation en milieu fondu

With a global market exceeding four million tons per year, acrylic acid (AA) is a major intermediate chemical. The current AA synthesis is based on propylene, which is produced from oil. Thus, a novel production route is envisioned, based on glycerol, a green byproduct of oleochemistry and biodiesel production. However, current crude biobased AA contains a higher proportion of PA than AA from petrochemical origin. Classical purification techniques of AA cannot efficiently separate these two chemicals. In a first part, liquid-solid phase diagram of the binary system AA + PA is determined. This liquid-solid equilibrium exhibits an peritectic behavior at 50.0% (mol) d’AA, a eutectic point at 25.65% (mol) d’AA and thus, this diagram is favorable to the purification of AA. First purification tests by static solid layer melt crystalliza tion show promising results: a correct separation efficiency for a yield varying between 60 et 70 %. To improve heat and mass transfer, dynamic crystallization set-up are developed, including a falling film crystallizer. This set-up multiplies by 2.8 the productivity of purification, while keeping a good separation efficiency. To reduce supercooling and to keep a good heat transfer despite the crystalline layer which is a thermal insulator, micro-and milli-structured crystallization surface are considered. Productivity is further improved and heat transfer modeling confirms the experimental results. To be nearer to industrial conditions, synthetic crude bio-AA is purified. Melt crystallization can separate all the impurities which are present in the medium. To scale the overall process a cascade model of closed crystallizers with recycling the differents phases, is proposed. The intensification of the process of melt crystallization permits to consider the implementation of the industrial process.Actuellement produit à partir du pétrole, une voie de synthèse de l’acide acrylique (AA) à partir du glycérol est envisagée. Cependant, cet AA bio-sourcé contient davantage d’acide propionique (AP) que l’AA issu du propylène. Les techniques classiques de purification ne permettent pas de séparer les deux acides. Le diagramme de phases liquide-solide du binaire AA + AP est déterminé. Il présente un point eutectique à 25,65 % (mol) d’AA, un point péritectique à 50,00 % (mol) d’AA et donc, un large domaine dans lequel l’AA cristallise thermodynamiquement de façon pure. Les essais de purification en mode statique sur paroi froide affichent des résultats prometteurs, une efficacité de séparation correcte pour un rendement de 60 %. Afin d’améliorer les transferts de matière et de chaleur, des dispositifs en mode dynamique sont mis au point dont un cristallisoir en film tombant. Ce dispositif permet de multiplier par 2,8 la productivité, tout en conservant une bonne efficacité de séparation. Afin de diminuer la surfusion et de maintenir un bon transfert thermique malgré une couche cristalline relativement isolante, des surfaces de cristallisation micro- et milli-structurées sont envisagées. La productivité est encore améliorée et la modélisation du transfert thermique confirme ces résultats expérimentaux. Afin de se rapprocher des conditions industrielles, un brut synthétique de bio-AA est purifié. La cristallisation en milieu fondu permet de séparer toutes les impuretés testées. Enfin, un modèle de cascade de cristallisoirs fermés, avec recyclage des différentes phases, est proposé afin de dimensionner le procédé global. Les essais en conditions presques réelles et l’intensification du procédé de cristallisation permettent d’envisager sereinement la mise en œuvre du procédé industriel

Design and development of a process purification of bio-acrylic acid by melt crystallization

Actuellement produit à partir du pétrole, une voie de synthèse de l'acide acrylique (AA) à partir du glycérol est envisagée. Cependant, cet AA bio-sourcé contient davantage d'acide propionique (AP) que l'AA issu du propylène. Les techniques classiques de purification ne permettent pas de séparer les deux acides. Le diagramme de phases liquide-solide du binaire AA + AP est déterminé. Il présente un point eutectique à 25,65 % (mol) d'AA, un point péritectique à 50,00 % (mol) d'AA et donc, un large domaine dans lequel l'AA cristallise thermodynamiquement de façon pure. Les essais de purification en mode statique sur paroi froide affichent des résultats prometteurs, une efficacité de séparation correcte pour un rendement de 60 %. Afin d'améliorer les transferts de matière et de chaleur, des dispositifs en mode dynamique sont mis au point dont un cristallisoir en film tombant. Ce dispositif permet de multiplier par 2,8 la productivité, tout en conservant une bonne efficacité de séparation. Afin de diminuer la surfusion et de maintenir un bon transfert thermique malgré une couche cristalline relativement isolante, des surfaces de cristallisation micro- et milli-structurées sont envisagées. La productivité est encore améliorée et la modélisation du transfert thermique confirme ces résultats expérimentaux. Afin de se rapprocher des conditions industrielles, un brut synthétique de bio-AA est purifié. La cristallisation en milieu fondu permet de séparer toutes les impuretés testées. Enfin, un modèle de cascade de cristallisoirs fermés, avec recyclage des différentes phases, est proposé afin de dimensionner le procédé global. Les essais en conditions presque réelles et l'intensification du procédé de cristallisation permettent d'envisager sereinement la mise en oeuvre du procédé industrielWith a global market exceeding four million tons per year, acrylic acid (AA) is a major intermediate chemical. The current AA synthesis is based on propylene, which is produced from oil. Thus, a novel production route is envisioned, based on glycerol, a green byproduct of oleochemistry and biodiesel production. However, current crude biobased AA contains a higher proportion of PA than AA from petrochemical origin. Classical purification techniques of AA cannot efficiently separate these two chemicals. In a first part, liquid-solid phase diagram of the binary system AA + PA is determined. This liquid-solid equilibrium exhibits an peritectic behavior at 50.0% (mol) of AA, a eutectic point at 25.65% (mol) of AA and thus, this diagram is favorable to the purification of AA. First purification tests by static solid layer melt crystallization show promising results: a correct separation efficiency for a yield varying between 60 et 70 %. To improve heat and mass transfer, dynamic crystallization set-up are developed, including a falling film crystallizer. This set-up multiplies by 2.8 the productivity of purification, while keeping a good separation efficiency. To reduce supercooling and to keep a good heat transfer despite the crystalline layer which is a thermal insulator, micro-and milli-structured crystallization surface are considered. Productivity is further improved and heat transfer modeling confirms the experimental results. To be nearer to industrial conditions, synthetic crude bio-AA is purified. Melt crystallization can separate all the impurities which are present in the medium. To scale-up the overall process a cascade model of batch crystallizers with recycling of the differents phases, is proposed. The intensification of the melt crystallization process permits to consider the implementation of the industrial proces

Développement, conception et mise au point d'un procédé de purification du bio-acide acrylique par cristallisation en milieu fondu

Actuellement produit à partir du pétrole, une voie de synthèse de l'acide acrylique (AA) à partir du glycérol est envisagée. Cependant, cet AA bio-sourcé contient davantage d'acide propionique (AP) que l'AA issu du propylène. Les techniques classiques de purification ne permettent pas de séparer les deux acides. Le diagramme de phases liquide-solide du binaire AA + AP est déterminé. Il présente un point eutectique à 25,65 % (mol) d'AA, un point péritectique à 50,00 % (mol) d'AA et donc, un large domaine dans lequel l'AA cristallise thermodynamiquement de façon pure. Les essais de purification en mode statique sur paroi froide affichent des résultats prometteurs, une efficacité de séparation correcte pour un rendement de 60 %. Afin d'améliorer les transferts de matière et de chaleur, des dispositifs en mode dynamique sont mis au point dont un cristallisoir en film tombant. Ce dispositif permet de multiplier par 2,8 la productivité, tout en conservant une bonne efficacité de séparation. Afin de diminuer la surfusion et de maintenir un bon transfert thermique malgré une couche cristalline relativement isolante, des surfaces de cristallisation micro- et milli-structurées sont envisagées. La productivité est encore améliorée et la modélisation du transfert thermique confirme ces résultats expérimentaux. Afin de se rapprocher des conditions industrielles, un brut synthétique de bio-AA est purifié. La cristallisation en milieu fondu permet de séparer toutes les impuretés testées. Enfin, un modèle de cascade de cristallisoirs fermés, avec recyclage des différentes phases, est proposé afin de dimensionner le procédé global. Les essais en conditions presque réelles et l'intensification du procédé de cristallisation permettent d'envisager sereinement la mise en oeuvre du procédé industrielWith a global market exceeding four million tons per year, acrylic acid (AA) is a major intermediate chemical. The current AA synthesis is based on propylene, which is produced from oil. Thus, a novel production route is envisioned, based on glycerol, a green byproduct of oleochemistry and biodiesel production. However, current crude biobased AA contains a higher proportion of PA than AA from petrochemical origin. Classical purification techniques of AA cannot efficiently separate these two chemicals. In a first part, liquid-solid phase diagram of the binary system AA + PA is determined. This liquid-solid equilibrium exhibits an peritectic behavior at 50.0% (mol) of AA, a eutectic point at 25.65% (mol) of AA and thus, this diagram is favorable to the purification of AA. First purification tests by static solid layer melt crystallization show promising results: a correct separation efficiency for a yield varying between 60 et 70 %. To improve heat and mass transfer, dynamic crystallization set-up are developed, including a falling film crystallizer. This set-up multiplies by 2.8 the productivity of purification, while keeping a good separation efficiency. To reduce supercooling and to keep a good heat transfer despite the crystalline layer which is a thermal insulator, micro-and milli-structured crystallization surface are considered. Productivity is further improved and heat transfer modeling confirms the experimental results. To be nearer to industrial conditions, synthetic crude bio-AA is purified. Melt crystallization can separate all the impurities which are present in the medium. To scale-up the overall process a cascade model of batch crystallizers with recycling of the differents phases, is proposed. The intensification of the melt crystallization process permits to consider the implementation of the industrial processMETZ-SCD (574632105) / SudocNANCY1-Bib. numérique (543959902) / SudocNANCY2-Bibliotheque electronique (543959901) / SudocNANCY-INPL-Bib. électronique (545479901) / SudocSudocFranceF

Hydrometallurgical Process to Recover Cobalt from Spent Li-Ion Batteries

The growth of the lithium-ion battery industry requires a secure supply of raw materials and appropriate end-of-life management of batteries. In almost five years, global cobalt consumption has increased by nearly 30%, driven mainly by rechargeable batteries. Consequently, several risks have been identified for cobalt, in particular the growing demand for electric vehicles, which could exceed current production. Therefore, research into the recovery of this critical metal, from industrial or urban waste, is particularly important in the years to come. In this study, cobalt is recovered from a lithium-ion battery leachate in hydroxide form. The thermodynamic simulations performed with Visual Minteq showed that it was possible to recover 99.8% of cobalt (II) hydroxide at 25 °C. Based on these results, experiments were conducted to validate the hypotheses put forward and to compare the results obtained with the simulations performed. Experimentally, several operating parameters were studied to determine the optimal conditions for cobalt recovery, in terms of yield, filterability, and selectivity. Results obtained in a batch reactor allowed the determination of the temperature conditions to be applied in continuous reactor. The cobalt (II) hydroxide precipitation in continuous reactor was carried out under different pH conditions. It was then possible to determine the optimal conditions for cobalt recovery in terms of yield and filterability. Results showed that working at pH 9 would effectively meet the desired criteria. Indeed, cobalt recovery is close to 100% and filtration flow rate is three times higher. Results obtained allow a better understanding of cobalt (II) hydroxide precipitation

A purification route of bio-acrylic acid by melt crystallization respectful of environmental constraints

International audienceBio-acrylic acid (AA) is produced from glycerol, a by-product of biodiesel production and oleochemistry. However, conventional purification techniques cannot purify this biobased AA owing to its impurity profile and the significant content of propionic acid (PA). The liquid–-solid phase diagram of the binary AA + PA shows that acrylic acid crystallizes ais a pure form from melts containing between 50 and 100% (mol/mol) of AA. Thus, a new falling film melt crystallization device has been developed and tested in which: – supercooling is limited by the use of a crystallization surface made of 316L stainless steel, – melt is thermostated, – visual observation of the crystal layer is possible, and – morphology of the crystal layer limits the retention of impure liquid. Purification tests in this falling film device show that AA is separated from the PA in reduced crystallization cycle times and high crystallization yields

Intensification of falling film melt crystallization process through micro and milli-structured surfaces

International audienceThis paper shows how falling film melt crystallization process can be intensified by using micro/ milli-structured surfaces. This work takes part in the development of purification techniques of bio-acrylic acid. The current acrylic acid synthesis is based on propylene, a petroleum derivative. Thus, a new production route of a bio-acrylic acid is developed, based on glycerol, a green by-product of oleochemistry and biofuel industry. However, the impurity profile of this bio-AA differs from that of propylene-based: crude bio-AA contains much more propionic acid (PA). Classical purification techniques do not allow the separation of these two chemicals whose structures are similar. [1] showed that falling film melt crystallization halves propionic acid contents in purified AA with yields reaching 60% and purification time less than five hours. Increasing the exchange surface between the cold surface and the melt to purify can improve heat transfer, decrease purification time and intensify melt crystallization process. Thus, micro/milli-structured crystallization surfaces have been designed and tested. Results show that these innovative surfaces can increase productivity by 84%. Heat transfer has been modeled during the crystallization process, and it clearly appears that thermal gradient is divided by ten with milli-structured surface compared to smooth surface.

Fluoride removal from water by electrocoagulation with aluminium electrodes: effect of the water quality

International audienc