Yes / In this perspective paper, we present challenges and opportunities that the chemical, biochemical and related industries pose to the process system engineering community to help deliver reliable and novel sustainable alternatives. More specifically, we highlight the need for a systems approach where model-based sustainable process synthesis, design, and analysis serve as opportunities to tackle the challenges. Three technology areas (interlinked to each other) that impact the sustainability of earth, namely, chemical processes linked with CO2 capture and utilization, biorefineries and water desalination are selected to highlight our views as well as the need for further development of computer-aided tools to efficiently solve the large and complex mathematical systems the problems represent. Analysis of these problems and their reported solutions indicate that opportunity exists for development of a new class of model-based methods and tools and their integration with the currently available ones to obtain the desired sustainability development goals.

Microbial Fuel Cell is a novel technology that can be used for a waste water treatment in order to simultaneously remove carbonaceous matter and nitrogen while producing electrical power. Even if it is not an established technology so far, MFC could be a cost effective option for waste water treatment and the major challenge of this process will be the device scale-up. Exoelectrogenic bacteria are capable of converting the chemical energy of organic matter into electrical energy by transferring the electrons produced in the oxidation to the anode electrode. This project focused on developing a single device for nitrification, denitrification and carbon removal. Two double air-cathode single chamber MFCs are used to test the feasibility of this process that could replace the biological unit in a waste water treatment train. The cells tested in this study were manufactured with the purpose of achieving a high surface area on both the anode electrode (vitreous carbon foam) and the air-cathode electrodes (metallic mesh with diffusion layer and active layer) with different catalysts for the reduction reaction (cobalt and platinum). The bacterial biofilm growth is a fundamental step and the cells Open Circuit Potential was monitored during all the start-up period to determine the microorganism acclimation: a three days lag period was observed in both cells before the potential rise. The second cell was forced to reach higher voltage through an anode polarization and that seems to positively affect the biofilm stability at lower voltages transferring a greater amount of electrons and hence obtaining a higher current and power generation. For this reason after three weeks of inoculation the second cell reached an open circuit potential of 0.76 V which is a promising value for such a system. Electrochemical and biological tests were conduced in order to test the power production of the cell and the substrate removal from the waste water. Polarization curves were used to evaluate power generation (and the maximum production under a specific external load) and the cell voltage trend which is characterized by activation and ohmic losses: 32 mW/ and 41 mW/  are the power density normalized by cathode surface (72 ) reached by respectively first and second cell. The experimental conditions were varied from low to high temperature and from low to high inlet flow rate but the most affecting phenomenon seems to be the biofilm formation since significant voltage drops were noticed after long closed circuit operation. Higher cell voltage characterized the second cell thanks to more active cathode (platinum catalyst used) and more negative bacterial biofilm but a bigger drop in current generation over time affects the system performance and the most reliable reason is the shorter acclimation time compared to the first cell. Cyclic voltammetry tests were carried out on both electrodes to study the potential range of activity and determine an optimal operational voltage despite of mass transport or kinetic limitations. Substrate removal tests at different retention times in power generation conditions (external load 100 Ω) showed a relatively high total nitrogen consumption (maximum 72.2 %) for the first cell while lower values were achieved by the second system meaning that a longer acclimation period is beneficial for nitrifying and denitrifying bacteria to thrive on the cathode biofilm. Effluent pH level are almost similar to the initial values probably because of nitrification and denitrification protons offset.

No description available.

Depuis plus de 40 ans des chimistes se sont intéressés à l’extraction, à l’activité biologique et à la synthèse de l’homoharringtonine, un ester naturel de la céphalotaxine, qui est un puissant antileucémique, en vue de son utilisation thérapeutique, en particulier contre les leucémies résistantes aux inhibiteurs de tyrosine kinase. Ces alcaloïdes sont extraits de Cephalotaxus, des conifères originaires du sud de la Chine à croissance extrêmement lente et menacés d’extinction, la synthèse de ces alcaloïdes est nécessaire pour une utilisation thérapeutique.L’objectif de ce travail consiste à développer une synthèse concise de la (-)-céphalotaxine 1, afin de palier notamment le problème de sa pureté énantiomérique variable lorsqu’elle est issue de la matière première végétale. La stratégie développée dans ce travail nécessite d’effectuer un couplage de Heck avec des substrats désactivés et encombrés. Les résultats préliminaires ayant été décevants, le première objectif à consisté à développer l’utilisation de la méthode des plans d’expérience en synthèse totale, car l’efficacité de chaque étape a une répercussion importante sur le rendement en produit final. Dans une première partie, l’application d’un plan d’expériences a permis de pallier ce problème par une étude modèle pour déterminer les paramètres importants pour effectuer une telle réaction efficacement. Dans une deuxième partie, nous avons synthétisé les précurseurs et réalisé le couplage de Heck en vue de l’accès à un précurseur AC comportant tous les atomes de carbone du squelette de la céphalotaxine et les fonctionnalités requises pour sa cyclisation ultérieure en tétracycle ABCD. Enfin, nous avons fonctionnalisé les produits de Heck en position C3 par différents méthodes. Ces résultats ont permis de valider notre stratégie de synthèse. / For more than 40 years the chemists were interested in the extraction, in the biological activity and in the synthesis of the homoharringtonine, a natural ester of cephalotaxine, which is a powerful antileukemic compound of therapeutic use, in particular against the leukaemia resistant to tyrosine kinase inhibitors. These alkaloids are extracted from Cephalotaxus, conifers native of the South of China with extremely slow growth. The objective of this work thus consisted in developing a concise synthesis of the cephalotaxine, to limit the recourse to the endangered vegetable resource The developed strategy requires an intermolecular Heck-coupling of electronically and sterically deactivated demanding substrates. The preliminary results having been disappointing, the first objective consisted in developing the use of the model of the experimental design in total synthesis because the classic methodology of variation of a single parameter at the same time said of "one by one" was ineffective. The application of a complete factorial design overcomes this problem by a model study, allowing to determine the optimized parameters to make this coupling reaction effective. We then synthesized the precursors from naturally abundant safrol and 2,3-butanedione then realized the Heck coupling with the aim of the access to the precursor AC containing all the atoms of carbon of cephalotaxine and the features required for its later cyclization in pyrrolobenzazepine ABC fragment. The o-iodized homopiperonylic alcohol led in certain conditions to an isochromane through a tandem Heck-oxa-Michael reaction. Finally, we have functionalized the Heck and hydro-arylation products obtained with 69-70 % yield in position C3 by different methods allowing us to validate our strategy to access these alkaloids.

Depuis plus de 40 ans des chimistes se sont intéressés à l’extraction, à l’activité biologique et à la synthèse de l’homoharringtonine (HHT), un ester naturel de la céphalotaxine, qui est un puissant antileucémique utilisé pour le traitement des leucémies résistantes aux inhibiteurs de tyrosine kinase. Ces alcaloïdes sont extraits de Cephalotaxus, des conifères originaires du sud de la Chine à croissance extrêmement lente et menacés d’extinction. Leur synthèse est donc nécessaire. L’homoharringtonine utilisée en thérapeutique est obtenue à partir de (-)-céphalotaxine d’origine naturelle, par greffage d’une chaîne latérale acide suivie de purifications longues et coûteuses. L’objectif de ce travail consiste à développer une synthèse concise de la (-)-céphalotaxine, afin de s’affranchir de la ressource naturelle, de ce fait de garantir un approvisionnement d’HHT de qualité constante et de développer des analogues de seconde génération.Les stratégies développées dans ce travail ont consisté à développer une synthèse très concise de la céphalotaxine, d’une part en valorisant un synthon ABC nitrile pour y introduire les deux atomes de carbone manquant au squelette de la céphalotaxine, et d’autre part à améliorer l’accès à une synthon analogue ABC ester pour en étudier la réactivité. Ces travaux ont conduit à décrire un nouveau complexe arène chrome pentacarbonyle analogue de céphalotaxine, une méthode originale et efficace de cyclisation anionique d’imide formant un squelette 3-benzazépine à l’aide d’une nouvelle combinaison de bases, le tert-butylate de potassium et le carbonate de potassium agissant en synergie, et une nouvelle méthode de solvolyse de nitrile aliphatiques ou aromatiques sous micro-ondes qui a été exemplifiée. / For over 40 years, chemists are interested in the extraction, biological activity and synthesis Homoharringtonine (HHT ), a natural cephalotaxine ester, which is a potent antileukemic used therapeutically, especially leukemias resistant against tyrosine kinase inhibitors. These alkaloids are extracted from Cephalotaxus, evergreen trees from southern China having extremely slow growth and are in extinction. Their synthesis is thus necessary. Homoharringtonine used therapeutically is obtained from (-)-cephalotaxine of natural origin, by grafting an acidic side chain followed by lengthy and expensive purifications. The objective of this work is to develop a concise synthesis of (-)-cephalotaxine to get rid of the natural resource, thereby ensuring a supply of constant quality and develop similar second generation of HHT.The strategies developed in this work has been to develop a very concise synthesis of cephalotaxine , firstly by enhancing an ABC nitrile synthon to introduce the two carbon atoms missing to the backbone of cephalotaxine , and secondly to improve access to similar ABC ester synthon to investigate its reactivity. This work led to describe a new arena complex chromium pentacarbonyle cephalotaxine analog, an original and efficient method of anionic cyclization of imide forming a 3-benzazepine skeleton using a new combination of bases , potassium tert -butoxide and potassium carbonate acting synergistically, and a new method of aliphatic or aromatic nitrile solvolysis under microwave which was exemplified.