Influence of droplet mutual interaction on carbon dioxide capture process in sprays

• Published in: Applied energy Vol. 92; pp. 185 - 193
• Main Authors: Chen, Wei-Hsin, Hou, Yu-Lin, Hung, Chen-I
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.04.2012; Elsevier
• Subjects: absorption; Applied sciences; Carbon capture and storage (CCS); Carbon dioxide; Density; Droplet mutual interaction; Droplets; Energy; Exact sciences and technology; Gas phases; gases; Greenhouse gas; Liquid phases; Mass diffusion number; Number density; prediction; Scrubber and spray; solutes; Sprayers; Sprays; Uptakes; Carbon capture and storage (CCS); Mass diffusion number; Droplet mutual interaction; Scrubber and spray; Number density; Greenhouse gas
• ISSN: 0306-2619; 1872-9118
• DOI: 10.1016/j.apenergy.2011.10.035

► CO 2 capture process by a single droplet under droplet mutual interaction is investigated. ► The number density of droplet is in the range of 10 3–10 6 cm −3. ► The droplet mutual interaction abates the CO 2 uptake amount by a single droplet. ► More CO 2 can be removed from the gas phase using a dense spray with larger droplet radii. Sprays are an important tool for carbon dioxide capture through absorption. To figure out CO 2 capture processes in sprays, the gas absorbed by a single droplet under droplet mutual interaction is investigated. In the study, the number density of droplet is in the range of 10 3–10 6 cm −3. By conceiving a bubble as the influence distance of the droplet–droplet interaction, the predictions indicate that the mutual interaction plays an important role on the absorption process and uptake amount of CO 2 when the number density is as high as 10 6 cm −3 with droplet radius of 30 μm. Specifically, the absorption period and CO 2 uptake amount of a droplet are reduced by 7% and 10%, respectively, so that the absorption rate is decreased compared to the droplet without interaction. Though the droplet mutual interaction abates the CO 2 uptake amount of a single droplet, a higher number density is conducive to the total uptake amount of CO 2 from the gas phase to the liquid phase. With the number density of 10 6 cm −3 and increasing the droplet radius from 10 to 50 μm, CO 2 capture from the gas phase to the liquid phase is intensified from 0.35% to 47.8%, even though the droplet–droplet interaction lessens the CO 2 uptake amount of a single droplet by a factor of 48%. In conclusion, a dense spray with larger droplet radii enhances the droplet–droplet interaction and thereby reduces CO 2 capture capacity of single droplets; but more solute can be removed from the gas phase.