WAVEINCORE

The development of CO₂ capture technologies is not only an essential lever for resilience scenarios in the face of global warming, but also contributes to the deployment of renewable, carbon-free energies. The processes operating the capture of CO₂ emissions by its selective absorption in solvents are among the most mature technologies and ready for industrial deployment. However, the energy efficiency of these processes, which require the implementation of two stages of gas-liquid separation in order to successively enrich the solvent in CO₂ and its regeneration, is low, less than 50%. More than half of the energy penalty of the process is actually due to the production from fossil fuels of superheated steam that feeds the desorption stage for the recovery of pure CO₂. Furthermore, large exchange surfaces are necessary, involving the implementation of large packing bed or plate columns which represent high investment costs, while the operating costs induced by the thermal degradation of the solvent, the production of superheated steam, the corrosion of equipment, the formation of toxic aerosols remain major issues.

Equipements MO dédiés à l'étude à l'echelle des contacteurs gaz-liquide prototypes des performances de désorption Co2, de solvant

Objective

The WAVEINCORE project aims to develop new desorption technologies for thermal regeneration of CO₂ enriched solvents, today considered as benchmark or promising for CO₂ capture. These technologies are based on the concept of spent solvent regeneration by microwave (MW) irradiation. The MW desorption technologies to be developed have the potential for drastic reduction of energy consumptions and solvent losses by working at temperature below 100°C, with the possible use of renewable electricity. Drastic lowering of water needs to operate the CO₂ desorption process and reduction in size of the contactors to be operated are expected to bring important additional benefits.

Used method

The development of models accounting for the local interacting phenomena between the MW fields and the transfer-reaction mechanisms taking place in the solvent phase is one of the main objectives of the WAVEINCORE project. It must be emphasized that no modeling approach addressing the coupling between MW irradiation and reactive gas-liquid systems has been developed so far: the knowledge to acquire in this area is completely new. These models are applied to the benchmark MEA (methylethanolamine) solution and will be adapted to a selection of last-generation solvents, for which thermophysical, dielectrical and thermodynamic properties are fully characterized, accounting for their dependence on temperature and dissolved gas concentrations.

Profil de température simulé du solvant en écoulement sous champ micro-ondes à l’échelle d’une fibre creuse à membrane poreuse.

With the aim to describe the transfer reaction-phenomena at the local scale, the modeling approach was initially developed to describe CO₂ desorption rates when the solvent is flowing into a single porous hollow fiber membrane place in a glass tube submitted to MW irradiation.  The numerical model simulates experimental data obtained from an experimental set-up composed of a solid-state MW generator operating at the frequency of 2450 MHz, a waveguide applicator equipped with a 3-stub tuner along with a sliding short circuit for impedance matching. The validity of the simulation model is so assessed by comparing experimental data with predicted outlet solvent temperature and CO₂ desorption rates. The modelling approach serves as a theoretical basis helpful for the design and optimization of membrane contactor prototypes to be integrated to a MW equipment, which performances are experimentally investigated at the lab-scale. For different contactor configurations, CO₂ desorption capacities, heating rates and energy consumptions are investigated as a function of the operating parameters.

Schéma de l’installation expérimentale pour l’étude à l’échelle d’une fibre à membrane poreuse de la désorption CO2 de solvant par chauffage MO.

Next steps

The design of a demonstrator in a real industrial environment will be considered to complete the equipment of the MINERVE "Power to Gas" experimental platform. The demonstrator could make it possible to capture the CO₂ from the combustion emissions of the boilers supplying the collective heating network of the Chantrerie site in order to supply the methanation reactors. A techno-economic analysis will be carried out, based on optimized energy integration scenarios in order to assess the potential for scaling up the proposed technology.

Role of the school

This project, coordinated by Pascaline Pré, professor in the department of energy systems and environment at IMT Atlantique, is part of the field of expertise of the VERTE team of the GEPEA laboratory, which develops processes applied to the treatment of industrial emissions and purification of energy gas vectors. It involves Professor Sébastien Curet from the OSE team at the GEPEA laboratory, an expert in the field of heat treatment by microwave heating. The two academic partners are co-supervising Ali Hajj's thesis, under a CIFRE contract with the company SAIREM, which has provided its know-how in the design of the microwave equipment dedicated to the experimental studies of the desorption contactor prototypes.

Partners

The WAVEINCORE consortium associates two academic partners of the GEPEA laboratory: IMT Atlantique and ONIRIS, as well as the French company SAIREM, developer and manufacturer of industrial MW equipments. The potential of application of such a technology is huge considering the needs for industrial decarbonization. The WAVEINCORE project will bring new knowledge to operate MW technologies in industrial applications still to be explored.