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Reference : UMR8181-SEBROY-005
Workplace : VILLENEUVE D ASCQ
Date of publication : Monday, October 4, 2021
Scientific Responsible name : Sébastien Royer
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 1 December 2021
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
The transformation of lignocellulosic biomass into fuels or synthons of interest is an essential issue for reducing the environmental impact associated with the use of fossil resources. Contrary to cellulose and hemicellulose, lignin is a resource that is still not very well valorized. Different technologies exist for lignin liquefaction, but fast pyrolysis has undeniable advantages. It can convert 60-75% of lignocellulosic biomass into crude bio-oil, and it operates continuously in an inert environment and without solvent consumption. However, the bio-oil must be upgraded to be valorized. Containing up to 55% of phenolic compounds, it is a source of simple aromatic hydrocarbons (BTX). Catalytic hydrodeoxygenation (HDO) is the most suitable catalytic process to transform phenolic monomers into BTX. The catalyst, by selectively activating the C-O bonds, will allow the deoxygenation of phenolic compounds while avoiding their hydrogenation.
The project aims at developing original catalysts for the deoxygenation of lignin pyrolysis vapors, with the goal to improve the yield of aromatic hydrocarbons. In order to gather skils in materials chemistry, molecular modelling, heterogeneous catalysis and process engineering, the project team associates 5 laboratories, labelled by CNRS: UCCS (Univ. Lille), IC2MP (Univ. Poitiers), and L2CM, LPCT, and LRGP (all three from Univ. Lorraine). The skills thus gathered allow the development of a multi-scale approach, from ab initio modeling at the molecular scale of surfaces to the study of catalyst performance on lignin pyrolysis vapors from a continuous hydropyrolysis process.
The PhD project will aim at synthesizing heterogeneous catalysts based on abundant metals, whose key parameters will be optimized: (i) textural properties of the supports, and in particular the stabilization of a hierarchical porosity, (ii) oxophilicity / acidity of the surface, (iii) and fine characteristics of the metals (dispersion, localization and composition). Thus, silica supports with hierarchical porosities will be synthesized, modified by the introduction of different oxide phases (ZrOx, AlOx), and then the metal phases (Ni, Fe) will be dispersed in a controlled manner on the surface of the pores to obtain single atome to clustered supported catalysts. These catalysts will be studied for the HDO of model oxygenated molecules (m-cresol, anisole and guaiacol) under moderate hydrogen pressures (2-4 MPa) before being tested on real lignin in a reaction micropilot (IC2MP and LRGP partners). The properties of the catalysts (activity, aromatic yield, and stability) will be rationalized by DFT studies conducted on the adsorption of model oxygenated molecules, taking into account the effect of H2O, CO and CO2 inhibitors (LPCT partner).
The PhD student will work in the Catalysis and Solid State Chemistry Unit (UCCS), a joint CNRS - University of Lille research unit located in Villeneuve d'Ascq and specialized in heterogeneous catalysis. More specifically, he/she will join the MATCAT team, which is interested in the synthesis of catalysts and the study of their stability (http://uccs.univ-lille1.fr/index.php/fr/catalyse-heterogene/matcat). Scaling and shaping will be evaluated using the UPCAT technology platform of the Institut Chevreul. This platform, dedicated to the preparation of catalysts, is equipped with large-scale synthesis reactors, different shaping techniques (extrusion, granulation, 3D printing etc.) as well as specific analytical tools. A part of the thesis will be carried out within the L2CM laboratory, a joint research unit of the University of Lorraine and the CNRS.
The PhD student will have obtained a Master's degree or an engineering degree in chemistry or chemical engineering. A first experience in heterogeneous catalysis will be considered favourably.
A good level of French and/or English is mandatory. This will be assessed in the event of an interview.
Constraints and risks
The chemical risks associated with experimental work are minimised by the mandatory use of personal protective equipment, the presence of extraction hoods, and dedicated risk training.
Please attach a cover letter and your Lice and Master's transcripts with your CV.
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