Masters

Faire son stage de Master au laboratoire

Ammonia is recognized as a possible green energy carrier and can be used as H2-carrier. Ammonia unlike H2 is already deployed worldwide (for agriculture purposes), its transportation is easier than hydrogen which need be stored at high pressure gas or cryogenic liquid. By nature, ammonia is carbon-free and its oxidation offers the possibility of zero-CO2 emission. NH3 can be reduced into H2 and N2. Or it can be used directly in combustion devices (gas turbines, marine engines, …). However, it has a very low heat release compared to fossil fuels, and its combustion can be affected by the occurrence of instabilities. Thus, it requires to be burned with a co-fuel, preferably H2 in order to reach the zero-carbon emission target. The knowledge of the oxidation kinetics of NH3/H2 blend mixtures still must be further improved in order to find the appropriate conditions offering the best optimization for combustion devices.

 

Today, there are several detailed kinetic mechanisms representative of ammonia combustion. Most have been validated against measurements of global parameters such as laminar burning velocities and ignition delay times. These mechanisms must be consolidated from the measurement of chemical species in stabilized laminar flames.

 

The work program of this Master internship will consist in measuring the species involved in the NH3/H2 blend oxidation in flames. Species such as NH or NO will be detected and quantified using spectroscopic laser-based diagnostics (Laser-Induced Fluorescence and absorption). Experimental results will be compared to simulated ones using kinetic modeling tools (ChemkinPro or LOGEsoft).

 

Keywords: green energy, NH3, Laser Induced Fluorescence, stablized flames, kinetic chemistry,

Supervisor:LAMOUREUX Nathalie, DESGROUX Pascale

Tél : 03.20.43.49.30, E-mail : nathalie.lamorueux[chez]univ-lille[point]frnathalie.lamorueux(a)univ-lille.fr


                 

Combustion process is the universal way to produce energy from fuels (>80% of the world’s primary energy supply is currently generated via combustion in flame burners, car engines, airplane engines, etc.). Biofuels are considered as promising sources for renewable energy production to reduce CO2 emissions. Recent studies have shown that the combustion of oxygenated biofuels produces lower amounts of large-sized soot particles than conventional petroleum fuels. However, the biofuels could potentially generate higher amounts of small-sized soot particles and these particles contain a significant fraction of oxygenates including oxygenated polycyclic aromatic hydrocarbons (OPAHs) which are generally more toxic than classic PAHs. These small-sized particles can penetrate our respiratory system and trigger health problems.

 

Due to the presence of oxygen atoms in the chemical structure of biofuels, the reaction mechanism involved during soot formation processes is expected to be much more complex as compared to conventional fuels. Understanding this mechanism is therefore very challenging, but it is a prerequisite step towards developing cleaner combustion technologies of biofuels. PAHs were proven to be the origin of soot formation, while the role of OPAHs and their chemistry are still less understood and will be explored in this internship.

 

Concretely, the master student will first be trained in the use of the modelling tools necessary to achieve the project's objectives. In parallel, he/she will carry out bibliographical studies on the project's theme. Then, he/she will perform simulations on the formation/decomposition of OPAHs resulting from biofuel combustion using a kinetic model currently being developed in the laboratory. This can help us to validate the model using literature experimental data. These numerical simulations with complex chemistry will be carried out with the Chemkin-PRO software, under different reactor conditions (flow reactor, flame, etc.), temperature and pressure. The expected results will be used to analyse the formation chemistry of OPAHs and related PAHs, which will provide a solid basis for developing a long-term proposal on the mechanism of soot formation in biofuel combustion.

 

 

Key words: Biofuels, kinetic model, OPAHs, soot, alternative fuels, Chemkin-PRO.

Supervisor: TRAN Luc-Sy and LIZARDO HUERTA Juan-Carlos  

Tél : 03.20.43.49.78, E-mail : luc-sy.tran(a)univ-lille.fr and juancarlos.lizardohuerta(a)univ-lille.fr

Collaborator: Abderrahman El Bakali, abderrahman.el-bakali(a)univ-lille.fr

International Master 2 Atmospheric Sciences: Research Training 2021-2022

CaPPA Work Package:     WP-1 or WP-2 or WP-5 

 

 

According to the literature, several authors have applied classical models such as Langmuir, Freundlich, or Langmuir–Freundlich to theoretically interpret the adsorption isotherms of pollutants on the adsorbent surfaces. However, most of these models do not provide any indications about the adsorption mechanism, and the isotherm equations of Freundlich or Langmuir–Freundlich have no physical significance or relationship with the physico-chemical parameters involved in the adsorption process. The modelling via application of statistical physical models is an advantageous method that can provide a better understanding of the adsorption mechanism at molecular level. Therefore, the objective of this subject is to attribute new physicochemical interpretations at molecular level of the adsorption mechanism of pollutants at different temperatures. In particular, the adsorption mechanism will be analyzed in studying the effect of temperature of all adequate model parameters.

 

This project will also aim to contribute to a larger research program devoted to the study of physico-chemical processes (Labex CaPPA, CPER Ecrin). This work will be conducted in collaboration with different research groups worldwide (Comenius University in Bratislava, Monastir University). The work will take place at PC2A laboratory, Lille University.

 

Keywords: Adsorption, pollutants, activated carbon, modelling

Supervisor: LOUIS Florent

Email: florent.louisuniv-lille.fr

International Master 2 Atmospheric Sciences: Research Training 2021-2022

CaPPA Work Package:     WP-2

 

 

Combustion chemistry of saturated cyclic ethers

More than 90% of fuels consumed worldwide today are petroleum-based. Greenhouse gas emissions and the exhaustion of their reserves are currently main concerns of the uses of petroleum-based fuels. A view to the next three decades shows that the demand for energy for transportation will rise by approximately 70%. Cyclic ethers, which are being considered as promising biofuels and can be produced from non-food plants, such as lignocellulosic biomass (agricultural waste, forest residues, wood, dedicated plants, etc.), are of increasing interest as alternatives to petroleum-based fuels. These biofuels offer the long-term promise of fuel-source regenerability and now provide opportunities to extend the petroleum era, as blending agents with petroleum-based fuels or as complete replacement. A good understanding of the combustion chemistry of the cyclic ethers is essential in development of reliable kinetic models for predicting the combustion and emissions of these biofuels. However, the ring size effects of the three to six membered saturated cyclic ethers are still not well understood and will be explored in this internship using modelling approaches.

 

Concretely, the master student will first be trained in the use of the modelling tools necessary to achieve the project's objectives. In parallel, he/she will carry out bibliographical studies on the project's theme. Under supervisors’ support, he/she will establish a single kinetic model for the studied cyclic ethers and test the model by comparing model simulations with literature experimental data. These numerical simulations will be carried out with the Chemkin-PRO software, under different reactor conditions (flame, jet-stirred reactor, flow reactor, etc.). The expected results will be used to analyze the combustion chemistry of the studied cyclic ethers and the influence of the ether ring size on fuel reactivity and product emissions.

 

Key words: Biofuels, kinetic model, cyclic ether, alternative fuels, Chemkin-PRO.

Supervisor: FENARD Yann and TRAN Luc-Sy

contact: 03.20.43.49.78,

 

 

yann.fenard(a)univ-lille.fr and luc-sy.tran(a)univ-lille.fr

International Master 2 Atmospheric Sciences: Research Training 2021-2022

CaPPA Work Package:     WP-1 or WP-2 or WP-5

 

Peroxy radicals are key radicals in tropospheric chemistry. They react, as recently shown, with the hydroxyl radical in the gas phase at an unexpectedly high rate. For instance, for ethyl peroxy, formation of activated ethylhydrotrioxide, followed by dissociation into methoxy and hydroperoxy radicals, is found to be the main reaction pathway, whereas ethylhydrotrioxide stabilization and methanol formation (from activated and stabilized ethylhydrotrioxide) are viable minor channels. Criegee intermediate formation is found to be negligible.

Since water vapor is the most abundant trace gas in the troposphere and it has been proved that atmospheric relative humidity has a strong influence in many atmospheric reactions, the effect of water vapor on this reaction has to be evaluated.

Molecular simulations will be performed by the intern to determine the thermochemical properties and kinetic parameters for the water-assisted reaction of OH with some RO2 for which no literature data exist. Calculations will be compared to experimental data from the FAGE reactivity setup existing at the laboratory in order to discuss simulations.

 

This project will also aim to contribute to a larger research program devoted to the study of atmospheric processes (Labex CaPPA, CPER Ecrin). This work will be conducted in collaboration with the Comenius University in Bratislava.

 

The work will take place at PC2A laboratory, Lille University.

 

Key words: Atmospheric chemistry, OH, RO2, CH3O2, C2H5O2, relative humidity, molecular simulations

Supervisor: TAAMALLI Sonia

E-mail : sonia.taamalli(a)univ-lille.fr

Collaborator: LAHCCEN Amaury

 

International Master 2 Atmospheric Sciences: Research Training 2021-2022

CaPPA Work Package:     WP-1

 

La qualité de l’air est un enjeu environnemental fort. Les impacts sanitaires et économiques ont fait et continuent de faire l’objet de nombreuses études. Sur le volet santé publique, depuis le début des années 2000, des travaux visent à mieux connaître la qualité de l’air, qu’il s’agisse de l’air ambiant extérieur ou, plus récemment, de l’air intérieur, et à déterminer les solutions efficaces de réduction des polluants. Depuis plusieurs années, ce sujet revient régulièrement dans le débat public.

 

Les études épidémiologiques et de santé publique montrent que l’exposition aux polluants de l’air est associée avec un accroissement de la mortalité et de la morbidité. Mais ces études utilisent comme proxy de l’exposition les mesures en air extérieur extrapolées au domicile des personnes, faute de pouvoir disposer de mesures réelles. Ceci engendre des biais potentiels importants, dus à des sources locales non prises en compte par les réseaux de surveillance de la qualité de l’air, ou plus grave encore, à l’exposition dans les milieux confinés, et à la variabilité temporelle rapide de certains phénomènes de pollution. Des capteurs miniatures, comme ceux développés dans le cadre du projet APOLLINE de l’Université de Lille, permettent d’accéder à cette exposition réelle, et donc de revisiter les conclusions des études épidémiologiques.

 

Le projet « Mesure de l’exposition individuelle aux particules sur le territoire de la MEL » vise à mieux connaître cette exposition individuelle. Dans ce projet, des capteurs (T, RH, particules 0.3-10 microns) sont fournis à des volontaires résidant sur le territoire de la Métropole Européenne de Lille. Ces volontaires portent les capteurs pendant une semaine. Les capteurs sont ensuite récupérés, et les données analysées. De cette façon, nous comptons atteindre plusieurs centaines de volontaires à la fin de 2022.

 

Nous recherchons un(e) étudiant(e) de Master pour participer à ce projet, qui participera aux campagnes de mesure :

-          étalonnage des capteurs (T, RH, particules) en laboratoire

-          distribution et récupération des capteurs aux volontaires recrutés pour l’étude

-          analyse des résultats

-          rendu vers les volontaires

 

Les candidats recherchés doivent être inscrits dans un master de chimie atmosphérique ou de sciences de l’environnement ou de physicochimie analytique ou de santé publique... En plus de ces compétences scientifiques, il est nécessaire de faire preuve d’un excellent sens relationnel et pédagogique, et d’une maîtrise du français, pour pouvoir interagir efficacement avec les volontaires.

 

 

Mots-clés : qualité de l’air, capteurs miniatures, particules, exposition individuelle, science citoyenne

 

Contacts : Benjamin Hanoune, benjamin.hanoune()univ-lille.fr                          

Les Masters en cours