Effect of solution height on carbon dioxide absorption using high frequency ultrasonic irradiation

Technology for capturing CO2 is gaining attention due to their potential in reducing the amount of CO2 in the atmosphere and opportunities to reuse or transform the captured CO2 into other valuable resources. This technology is commonly used during the welling for natural gas where the gas reservoir contains high concentration of CO2. High frequency ultrasonic assisted absorption can be used to generate ultrasonic fountain that provides abundant fine droplets for CO2 absorption. The height of the solution will affect the ultrasonic streaming velocity, which will then affect the amount of the generated droplet. In this paper, the high frequency ultrasonic assisted absorption was studied using different height of monoethanolamine (MEA) solution at varied ultrasonic power. The experiment was conducted using a pressurised batch process. The absorption rate was determined from the pressure drop profile. Based on the experiment results, the height of the solution has significantly affected the performance of the ultrasonic assisted absorption. The CO2 absorption coefficient has been increased from 0.0388 to 0.0470 kmol.m-3.h-1.kPa-1 by decreasing the height of solution from 50 mm to 25 mm under the ultrasonic power of 13.2 W. The thresholds of the ultrasonic fountain have been decreased from approximate 3 W to 1 W by decreasing the height of solution from 50 mm to 25 mm. Overall, the height of the solution in the ultrasonic reactor is one of the important factors to be considered for the ultrasonic assisted absorption process for CO2. Copyright © 2017, AIDIC Servizi S.r.l..