CO2 Absorption Air Contactor Prototype
CO2 capturing and removal processes can be intensified by a volumetric cell chamber, called air contactor, where gas flow components are effectively separated and sudden thermodynamic conditions can be supported in order to provide optimal process efficiency and intensity (Fig.1).
Fig.1 CO2 capturing air contactor, high absorption surface.
New design of electric field air contactor is composed by a stack of electrodes within pressure and temperature suppression chamber (Fig.1). Electric field is used as a process intensifier where heavier polarized molecules have a significant velocity drop along the chamber movement.
Fig.2 Dimensions of studied air contactor
For that purpose, a 3D printed CO2 absorption air contactor with increased high specific absorption internal surface has been manufactured. It is volumetrically printed by electrically conductive polymer. Different internal structure architectures are considered and compared according to aerodynamic pressure drop (Fig.2).
Fig.3 Modeled geometry of the porotype.
3D Printed Model
A 3D model of the proposed CO2 absorption air contactor was created in order to study heat distribution, velocity and pressure inside. On Fig.2 is shown drawing of created model and its dimensions.
On Fig.3 is shown created 3D model of investigated air contactor and on Fig. 4 is shown a 3D printed prototype.
Fig.4 Modeled 3D printed prototype.
3D printed prototype is manufactured as an aerodynamic testing real example with required huge absorption inner surface. It is made to test the 3D printing technology capabilities for small channel making and internal surface roughness quality which are essential in aerodynamics calculations. Fused deposition modeling (FDM) 3D printing technology is employed via Prusa i3 MK3S+. 3D printing internal and exterior volumetric parameters of the prototype are presented in Fig.5.
Fig.5 3D printing internal and exterior parameters of the prototype.
Gas Monitoring Testing Chamber
Gas monitoring chamber scheme is presented in Fig.1. Mixing chamber is used as a preconditioner for adjusting gas mixture content and thermodynamic condition. After that a vacuum pump (#1) is transferring the content in the main longitudinal testing chamber. There CO2 absorption contactor under testing is placed for testing. In the testing chamber operational conditions could be adjusted and thermodynamic monitoring can take place. Second vacuum pump (#2) is used to ensure controllable outflow from the test chamber.
Main technical properties of the gas diffusion monitoring chamber are: size: 120 mm outer diameter × 1000 mm axial length; Maximum vacuum level: > 50 Pa; Fabricated of transparent polyacrylate, sealed to ensure uniform and ultra-low gas leak rate. Includes a vacuum gauge and two metering valves to permit flushing of the chamber with purge gas before application of vacuum and air + CO2 mixture after. Two vacuum pumps are used for input and output leads control. Test system is perfect for controllable mixing liquids, vacuum encapsulation, and general purpose vacuum experiments. It provides a safe, convenient way to transport moisture- and particle-sensitive materials.
Fig.6 Gas monitoring chamber scheme.
Polyacrylate material provides full visibility of internal parts. Installation of cable feed-through is possible.
In the main testing mode CO2 capturing contactor design is placed in the testing chamber (Fig.7a). Main thermodynamic factors, P – pressure, C- concentration, T-temperature, are controlled during the testing process. If P and T are fixed, change in CO2 concentration before (C1) and after the contactor (C2) could be measured in time (Fig.7a). In case of thermal stimulation of absorption process, temperature variation may also be of interest in testing (Fig.7b). Next testing mode includes gas velocity measurements in the testing chamber, caused by CO2 contactor dynamic pressure drops due to drag forces along capturing channels (Fig.7b). At that mode data from input pump (#1) and output pump (#2) are taken to estimate integral velocity flow.
Other testing modes are also possible within the same chamber design. Transparent polyacrylate walls are making usable visual control means such as infrared detectors, video cameras, etc., that will reveille entire mixing process dynamics.
Fig.7 CO2 air contactor testing mode with longitudinal air flow.