Développement d un outil intégré pour la Modélisation de Procédés et l Analyse de Cycle de Vie (Ecoconception d usines de procédés et application à la production d eau potable)

Des outils adaptés pour s attaquer aux problématiques environnementales sont nécessaires mais malheureusement absents de l industrie. En effet, l introduction de nouvelles pratiques d écoconception dans l industrie des procédés est entravée par le manque de réalisme et de flexibilité des outils associés. Les objectifs principaux de ce travail de recherche étaient le développement d un outil intégré pour la modélisation de procédés et l analyse de cycle de vie (PM-LCA), ainsi que la formulation d une approche méthodologique affiliée pour l écoconception de procédés. L outil logiciel et l approche méthodologique sont appliqués à la production d eau potable.La revue de la littérature scientifique a permis d appréhender les efforts de recherche nécessaires. Les principales lignes directrices sont établies en conséquence.L outil développé, nommé EVALEAU, consiste en une bibliothèque logicielle de modèles de procédés unitaires permettant le calcul d inventaire de données en fonction de paramètres de procédés. L outil est embarqué dans le logiciel ACV Umberto® en complément de la base de données Ecoinvent. Uneboîte à outils pour l analyse de sensibilité, basée sur la méthode de Morris, est implémentée pour l identification des paramètres de procédés ayant une influence majeure sur les résultats d impacts environnementaux.L outil EVALEAU est testé sur deux études de cas - deux usines de production d eau potable existantes. La fiabilité de l approche est démontrée à travers la comparaison des calculs de qualité de l eau, de consommations d énergie et de matériaux avec les données réelles recueillies sur site. Une procédure d écoconception est expérimentée sur une chaîne de traitement complexe démontrant ainsi la pertinence des résultats de simulations et l utilité de l analyse de sensibilité pour un choix optimal des paramètres opératoires. En conséquence, ce premier outil PM-LCA est censé promouvoir l introduction de pratiques d écoconception dans l industrie de l eauAdapted tools for tackling environmental issues are necessary but they are still missing in industry. Indeed, the introduction of ecodesign practices in the process industry is hindered by the lack of realism and flexibility of related tools.The main objectives of this research work were the development of a fully integrated tool for Process Modelling & Life Cycle Assessment (PM-LCA), and the formulation of an affiliated methodological approach for process ecodesign. The software tool and the methodological approach are meant to be applied to water treatment technologies.The literature review leads to a better comprehension of the required research efforts. The main guidelines for the development of the software tool are stated accordingly.The developed tool, named EVALEAU, consists in a library of unit process models allowing life cycleinventory calculation in function of process parameters. The tool is embedded in Umberto® LCA software and is complementary to Ecoinvent database. A sensitivity analysis toolbox, based on theMorris method, was included for the identification of the process parameters mainly affecting the lifecycle impact assessment results.EVALEAU tool was tested through two case studies - two existing drinking water plants. There liability of the modelling approach was demonstrated through water quality simulation, energy and materials inventory simulation, compared with site real data. An ecodesign procedure was experienced on a complex water treatment chain, demonstrating the relevance of simulation results and the usefulness of sensitivity analysis for an optimal choice of operation parameters.This first developed PM-LCA tool is dedicated to foster the introduction of ecodesign practices in the water industryTOULOUSE-INSA-Bib. electronique (315559905) / SudocSudocFranceF

Mechanisms of instabilities of high-frequency combustion and application in engines-rockets.

Cette thèse présente une étude des instabilités haute-fréquence dans les moteurs-fusées. Ce phénomène, qui a posé de nombreux problèmes dans les programmes de développement de moteur, est abordé de trois façons complémentaires : expérimentalement, théoriquement et numériquement. Premièrement, des expériences sont menées afin d identifier les principaux processus et d apporter les mécanismes ayant lieu lorsque le moteur devient instable. Pour parvenir à ce stade, un nouveau modulateur (VHAM), capable de créer des ondes acoustiques représentatives de ce qui se produit dans un moteur réel, est conçu et caractérisé. La deuxième partie concerne l analyse théorique. Deux modèles (FAME, SDM) sont développés en suivant les principales conclusions de la campagne expérimentale : les oscillations de dégagement de chaleur sont dues au mouvement transverse des flammes, et le phénomène est déclenché lorsque des gouttelettes deviennent suffisamment petites pour être convectées par le champ acoustique. En utilisant ces modèles comme base de référence, un code numérique (STAHF) est présenté. Son but est de rendre compte des mécanismes déjà identifiés pour un coût de calcul faible. Il est ensuite montré qu il peut être utilisé pour étudier des moteurs-fusées grandeur nature. La LES compressible est choisie pour étudier l interaction entre l acoustique et la combustion numériquement. Un nouveau modèle de combustion pour flammes non-prémélangées basé sur une hypothèse de chimie infiniment rapide est présenté et validé sur une flamme bien documentée (H3). Il est ensuite utilisé pour étudier l interaction entre une onde acoustique transverse et la flamme H3. Une comparaison entre le terme source de Rayleigh calculé à partir de la simulation et celui prédit par le modèle théorique FAME est finalement menée.This thesis presents a study of high frequency instabilities in rocket engines. This issue, which has plagued many engine development programs, is approached by three complementary viewpoints: experimental, theoretical, and numerical. First, experiments are carried out to identify the main processes involved and bring forth mechanisms taking place when an engine becomes unstable. To achieve this stage, a new modulator (the VHAM), capable of creating acoustic waves representative of what occurs in an actual engine, is designed and characterized. The second part of this thesis concern theoretical analysis. Two models are developed following the main conclusions of the experimental campaign: heat release oscillations are due to the transverse flames motion, and the phenomenon is triggered when droplets become small enough to be convected by the acoustic field. Using these models as a baseline, a numerical code (STAHF) is presented. Its purpose is to account for mechanisms identified previously for little computational cost. This code is validated on particularly responding situations observed during experiments. It is then shown that it can be used to study real scale rocket engines. The third point of view adopted to address the problem is numerical simulation. Full compressible LES is chosen to study the interaction between acoustics and combustion. A new combustion model for non-premixed flames with infinitely fast chemistry is presented and validated on a well documented flame (H3). It is then used to study the interaction between a transverse acoustic wave and the H3 flame. A comparison between the Rayleigh source term computed from the simulation and the one predicted by the theoretical model FAME is conducted eventually.CHATENAY MALABRY-Ecole centrale (920192301) / SudocSudocFranceF

An integrated "process modelling-life cycle assessment" tool for the assessment and design of water treatment processes

International audienceThe application of Life Cycle Assessment (LCA) to the design of water treatment plants is hampered by: (1) a large diversity of unit processes, (2) the high variability of the operation conditions in relation with the water quality input, and (3) the range of possible technical solutions to fulfil the treatment needs. For a consistent prospective assessment, the LCA should be based on the simulated functioning of the unit processes rather than on average data, as it is most often the case when no real data are available. Here, a novel, integrated and flexible process modelling-life cycle assessment (PM-LCA) tool for design and LCA of water treatment technologies is presented. The tool (EVALEAU) was developed in UmbertoA (R) (v5.5) using the Python language for code scripting. A library of unit process (UP) modules was built. Each module is a detailed and highly parameterized model of a specific water treatment process, which is further linked with the software PHREEQCA (R) for water chemistry calculation. Input data are: water composition, design, operation parameters, including literature or user-defined values. The modules are linked to Ecoinvent datasets (v2.2) for background processes. By combining the modules, water treatment chains can be designed and evaluated in UmbertoA (R) with a high level of detail and specifications. A sensitivity analysis toolbox (Morris method) was included for the identification of the process parameters mainly affecting the impact results. The tool was successfully applied to the test bed case of an existing drinking water plant located in the Paris region. The conventional LCA results, based on average recorded data, were compared with the results obtained using the PM-LCA tool. Modelling results for technical parameters were also compared with data collected on site. An overall good agreement between simulations and real data was obtained, proving the relevance of the developed tool. Sensitivity analysis indicated that ozone production and transfer into water are the main technological parameters influencing climate change (taken as example since it is of high interest for stakeholders), which have therefore to be fine-tuned. The EVALEAU tool successfully solves the challenge of linking LCA results to the related engineering design choices, from the assessment and eco-design perspectives. The concepts and methodologies embedded within the tool provide the user with complementary views of the designed system, in terms of potable water quality, design and operation parameters and environmental impacts generated over its life cycle

Analysis and modelling of entropy modes in a realistic aeronautical gas turbine

A combustion instability in a combustor typical of aero-engines is analyzed and modeled thanks to a low order Helmholtz solver. A Dynamic Mode Decomposition (DMD) is first applied to the Large Eddy Simulation (LES) database. The mode with the highest amplitude shares the same frequency of oscillation as the experiment (approx. 350 Hz) and it shows the presence of large entropy spots generated within the combustion chamber and convected down to the exit nozzle. The lowest purely acoustic mode being in the range 650-700 Hz, it is postulated that the instability observed around 350 Hz stems from a mixed entropy/acoustic mode where the acoustic generation associated with the entropy spots being convected throughout the choked nozzle plays a key role. A Delayed Entropy Coupled Boundary Condition is then derived in order to account for this interaction in the framework of a Helmholtz solver where the baseline flow is assumed at rest. When fed with appropriate transfer functions to model the entropy generation and convection from the flame to the exit, the Helmholtz solver proves able to predict the presence of an unstable mode around 350 Hz, in agreement with both the LES and the experiments. This finding supports the idea that the instability observed in the combustor is indeed driven by the entropy/acoustic coupling

Formalization of a technical procedure for process ecodesign dedicated to drinking water treatment plants

Nowadays rigorous methodologies for performing ecodesign of process plants are still missing in current industrial practices and in the literature. The use of a fully integrated Process Modelling and Life Cycle Assessment (PM-LCA) tool combined with appropriate mathematical analysis methods seems to be an audacious approach. A technical procedure for process ecodesign is formalized in this paper in order to address this issue. The proposed methodological approach is applied to a drinking water treatment plant. The EVALEAU tool, a PM-LCA integrated simulator based on a computational library of models for water treatment processes, is used including a tool box for sensitivity analysis. At first, a ground modelling scenario, representing the regular functioning of the plant is established and validated. An in-depth analysis of this plant model highlights the major environmental issues. Secondly, several technological solutions are tested in alternative modelling scenarios, which are derived from the ground one. Interesting technological solutions are then combined in one optimal scenario, which manages to decrease the environmental impacts (e.g. reduces "Climate Change" by 17.2%). At the same time, operational costs are increased by 10.8% showing opposite behaviour. Compared with field reality, the solutions proposed are realistic and demonstrate that the studied plant functioning is close to the optimum. (C) 2014 Elsevier Ltd. All rights reserved

Cost-performance indicator for comparative environmental assessment of water treatment plants

To compare potable water production plants on the basis of the environmental impacts generated by the treatment, including water resource depletion, Life Cycle Assessment (LCA) methodology is often used as referential. A comparison based only on the environmental impacts can however be misleading. Criteria for drinkability are usually defined as thresholds and the actual water quality gain achieved by different treatment chains shall be considered in the assessment for a fair comparison. Otherwise, chains treating low quality water resources could be disadvantaged as compared to alternatives using higher quality water resource, also when the depletion of the raw resource is included in the impact assessment. In this study, a novel Cost-Performance (CP) indicator has been developed and tested for the case of two existing water treatment plants located in the Paris Region. CP is the ratio between the total environmental impact generated by the treatment (i.e. the LCA score, eventually monetarised) and the total quality gain from raw to treated water. For the test case, three life cycle impact assessment methods, ReCiPe, Stepwise and Eco-costs (the latter two including monetarisation) have been considered. The water quality gain is based on 8 relevant parameters measured before and after treatment. The parameters are further aggregated using the French water quality valuation system SEQ-Eau. Paired t-test is then used to calculate the confidence interval for the average quality gain which then determines the confidence interval of the CP. Independent t-test on the CPs of the two alternative plants allows checking if their performances can be distinguished. Although in the specific test case the comparison is not conclusive, due to the similarity between the water quality gains, realistic breakthrough values have been obtained, especially using ReCiPe. The meaningfulness of the monetarisation of the LCA results has been highlighted as well. (C) 2012 Elsevier B.V. All rights reserved

Life Cycle Assessment of water treatment: what is the contribution of infrastructure and operation at unit process level?

International audienceIn the literature, Life Cycle Assessment studies of drinking water production systems do not show or fully clarify the contribution of the specific unit processes, of the plant infrastructure and of sludge spreading to the overall generated environmental impact. Nevertheless, these constitute key issues for the optimization and management of such plants. This article aims at providing a consistent and up to date assessment based on detailed operation and infrastructure design data at unit process level for two complex plants located in France. At the single score level, the study shows that the complexity of the treatment chain is not a reliable indicator of its environmental footprint. The overall generated impact is driven by the consumption of fossil resources, mainly related to electricity and activated carbon production. These consumptions are mainly concentrated at the settling and distribution unit processes. The contribution of infrastructure to the single score varies from 4% to 11%, with steel usage being the main contributor. The importance of toxicity generated by sludge spreading is still unclear because of the insufficient degree of precision and consistency of the assessment. In particular, significant variability of the toxicity of heavy metals is observed, ranging from 0.10 to 0.55 millipoints/kg sludge

Ovarian and peritoneal psammocarcinoma: Results of a multicenter study on 25 patients

International audiencePurpose: Psammocarcinoma (PK) is a rare disease of unknown origin. We aimed to report the characteristics, management and survival of patients operated on for PK within the French Network for Rare Peritoneal Malignancies (RENAPE) expert centers.Patients and methods: All consecutive cases of PK operated within all 26 RENAPE centers between 1997 and 2018 were retrospectively analyzed.Results: Twenty-five patients were identified. The median age was 53 years [range 17–78]. None of the patients had extra peritoneal metastases at diagnosis. A median of 6 cycles of carboplatin-based systemic chemotherapy was delivered in 52% preoperatively (n = 13) and 56% postoperatively (n = 14); associated with placlitaxel for 12 patients. All patients were operated on. The median PCI was 23 [0–33]. Eighty-four percent had a complete cytoreductive surgery through digestive (n = 7), spleen (n = 3), pancreas (n = 1) resections and/or multiple peritonectomies (n = 11). Five patients (20%) had intraperitoneal chemotherapy. Morbidity (Dindo-Clavien ≥3) was 12%. No postoperative death occurred. After a median follow-up of 42 months (range [2–194]), the median overall (OS) and progression-free (DFS) survival times were respectively 128 months and 31 months. Eighteen patients recurred (72%), mainly in the peritoneum (n = 16). Four of them (22%) were reoperated. The 5 and 10-year DFS rates were both 20.3%. The 5 and 10-year OS rates were 62% and 51.7%, respectively. A complete cytoreductive surgery was associated with a better OS and DFS in a univariate analysis.Conclusion: Complete cytoreductive surgery is the cornerstone of the PK's management as a primary treatment. Recurrence remains common and new adjuvant strategies seem needed