Study of SOx and NOx impact on amines degradation during post combustion CO2 capture

To limit greenhouse gas emissions, IFPEN is developing new amine-based solvents for CO2 capture in fumes (thermal power stations, steelworks, cement factories…). These mainly contain CO2, water, N2 and O2 but also different impurities such as sulfur oxides (SOx) and nitrogen oxides (NOx) at different concentrations depending on the emitter. In contact with these species, amines can undergo degradation, which leads to losses of amines and formation of volatile products which are potentially harmful to the environment. This degradation increases the costs of capture process and slows down its development. In the case of O2, this degradation has been extensively studied to understand the degradation mechanisms and provide more resistant amines. On the other hand, in the case of NOx and SOx, significant scientific questions remain.
For NOx, it is known that secondary amines can form nitrosamines and nitramines. However, a study that establishes structure-property relationships is clearly missing to predict the propensity of any secondary amine to form these species based on its chemical structure under process conditions.
For SOx, incomplete material balances suggest the formation of compounds other than sulfates or sulfites. It is therefore necessary to identify these degradation products and to elucidate their mechanisms of formation.
The objective of the thesis is therefore to answer these 2 questions to be able to anticipate the effects of NOx and SOx on the operation units and on the choice of amine-based solvents.
The reactions will be carried out on multi-reactor equipment in severed representative conditions. New analytical strategies should be developed to enable the reliable qualitative and quantitative analysis of the effluents. They will involve ion, gas and liquid chromatography, coupled with high resolution mass spectrometers together with specific sampling procedures. For quantitative methods, organic syntheses of standards may have to be carried out.

Keywords: CO2 capture and storage, environment, solvents, amines, chromatography, mass spectrometry

Academic supervisor    Dr, VIAL Jérôme, Laboratoire Sciences Analytiques, Bioanalytiques et Miniaturisation, CBI, ESPCI Paris PSL
Doctoral School    ED 388 : Chimie physique et chimie analytique de Paris centre
https://collegedoctoral.psl.eu/doctorat-psl/les-ecoles-doctorales/ed-388-chimie-physique-et-chimie-analytique-de-paris-centre/
IFPEN supervisor    Dr, GIREL Etienne, Separation department, etienne.girel@ifpen.fr
PhD location    IFP Energies nouvelles, Lyon, France
Duration and start date    3 years, starting in fourth quarter 2022
Employer    IFP Energies nouvelles, Lyon, France
Academic requirements    University Master degree chemical sciences
Language requirements    Fluency in French or English, willingness to learn French