In a world constantly seeking to reduce chemicals consumption and pollution all the while researching for new tools to improve food production and combat the spread of infections, the importance of new breakthrough technologies has become crucial. Imagine a technology able to convert efficientlytap water into a rich fertilizer or a powerful antimicrobial. Dream that this technology is also eco-friendly, cost effective and applicable anywhere in the world since it requires only electricity, air and water to operate. This powerful technology is not a fantasy and is the result of the combination of cold plasma (ionized gas) and water aerosol. Plasmas in contact with water can generate species such as nitrates and nitrites or hydrogen oxides and atomic oxygen. Thus plasma-aerosol technology constitute a nitrogen fixation technique or an advanced oxidation technique (depending on the control parameters) that is expected to be free of solvent and long-term residuals and therefore is eco-friendly and sustainable. Nowadays, the lack of knowledge on the mechanisms governing plasma-aerosols systems hinders their optimization and severely limits the full development of their agricultural applications. The objective of PLASMASOL is to bring new insight on plasma-aerosols so to finally unleash the full potential of this technology. The final aim is to pave the way to a new technology that has the potential to become a breakthrough solution in agriculture for the in-situ and on demand production of fertilizers and antimicrobials. No more need of coal or natural gas, no need of complex supply chains or infrastructures. Plasma-aerosol technology could minimize or even eliminate the environmental impact nowadays associated to the production, distribution and storage of agrochemicals.

This research project focuses on the fundamental study of breakdown phenomena in gases at atmospheric pressure in micrometer gap systems. The prediction of gas breakdown in micro-gaps is still a wide topic to explore, since its understanding cannot be explained the classical breakdown theory. This project proposes to investigate the elementary processes involved in the present conditions, in particular the role of electron field emission via tunneling electrons. Several key parameters will be studied such as the electrode geometry, surface materials, gas, pressure, electrical excitation waveform. Advanced experiments will be conducted involving optical laser spectroscopy techniques. The main outcome of this project will support to refine understanding of breakdown in micro-gaps and will unveil substantial fundamental knowledge to explain the deviation of breakdown prediction derived from the scaling Paschen’s law.

Chemical characterization is essential to the study of bioactive compounds in natural and biological samples but conventional preparative and analytical techniques are usually time, energy and solvent-intensive, posing environmental and health risks. Supercritical carbon dioxide (CO2) present an eco-friendly alternative due to its interesting physio-chemical properties. Prof. Wests research group has been developing approaches involving supercritical CO2 for two decades, and recently developed an integrated system combining supercritical fluid extraction (SFE) and supercritical fluid chromatography (SFC) for the on-line extraction and analysis of polar and non-polar bioactive compounds from plants. Although feasible, such coupling is very challenging, especially when targeting compounds with a wide range of polarities. The next step is thus to further improve the developed system and explore its applicability to other samples with different matrices and classes of compounds. Specifically, the use of unified chromatography (UC), an advanced version of SFC, will be investigated to further expand the efficiency and potential scope of the system. Since the interfacing of the two techniques is a major bottleneck preventing the system from reaching its full potential, finding innovative solutions to facilitate the extract transfer from the first to the second dimension is necessary. An important part of this project will thus be devoted to investigating new interface modalities to address the compatibility problems and instrumental issues pertaining to this hyphenation. To boost chromatographic separation power and facilitate structural elucidation, the potential of incorporating multidimensional (mD) separation steps while coupling the system with mass spectrometry (MS) will also be explored, to develop a novel on-line (mD-SFE)-(mD-SFC/UC)-MS system. Finally, the systems utility will be demonstrated through qualitative and quantitative analyses of real-life samples.

Europe is defining its trajectory to assume its ecological transition, its “Green Deal”, through the implementation of a set of political initiatives. In front of an inflexible guideline, considered sometimes dogmatic, the European Parliament aims to make Europe the first climate-neutral continent. Indeed, in the field of transport, the European Union (EU) has proposed to abolish sales of light vehicles (cars, vans, LCVs) using fossil fuels, as well as sales of heavy transport (trucks, buses), by 2035. Several technologies can meet these commitments: propulsion carried out by hydrogen internal combustion engines is one of them. The latter would allow the rapid decarbonization of some existing vehicles, thanks to the retrofit of Diesel engines into Hydrogen engines, and would allow then to offer new vehicles whose engines, from Diesel production lines, will be redesigned to be adapted to the combustion of hydrogen. However, Hydrogen internal combustion engines are also strategic, from an economic point of view, since the production plants, and the related jobs can be safeguarded locally. The PRISME laboratory, from the University of Orléans, engaged with Stellantis around a joint Openlab Energetics laboratory, for more than 10 years, and an ExplOe experimental platform, for 4 years; as well as with Renault Trucks within an ADEME-CORAM PL-H2 project (France 2030), has know-how, extensive experience and unique and recognized systems for hydrogen combustion. The "DEsign of Low emission and efficient Hydrogen Internal Combustion Engines" chair (acronym: DELHYCE) aims to build a methodology for retrofitting and redesigning Hydrogen internal combustion engines, based on small displacement diesel engines for commercial vehicles and larger displacement diesel engines for trucks. Two Stellantis engines and one Renault Trucks engine will then be optimized and tested. In particular, performances and NOx emissions r be highly optimized, subject to the constraints of controlling abnormal combustion, characteristic of these engines. In order to meet the industrial challenges and to remove scientific barriers, six tasks have been defined, involving six doctoral students: • Task 1, devoted to understanding the phenomena of Hydrogen combustion (injection, air-hydrogen mixture, combustion, auto-ignition and pollution); • Task 2, for the characterization of mixing phenomena in optical assess engines; • Task 3, devoted to the optimization of Stellantis engines: metal single-cylinder research engines will be developed for this task; • Task 4, dedicated to the optimization of Renault Trucks MH8 engine. The single-cylinder engine developed under the CORAM PL-H2 project will be reused; • Task 5, to propose new control laws dedicated to hydrogen internal combustion engines, especially during transient phases. Poly-cylinder engines will enable these control laws to be validated; • Task 6, dedicated to the promotion and dissemination of the results (a special effort will be made to involve university training but also to raise awareness among a younger audience). Thus, the ambition of the DELHYCE project, for the industrial components, is: • For Stellantis: to have hydrogen engines; • For Renault Trucks: to substantially improve the efficiency and maximum load of the MH8 engine in order to power 19-tonne demonstrators.