Abstract View
Reactive Uptake of Monoethanolamine (MEA) by Sulfuric Acid Particles
XIAOMENG TIAN, Yangxi Chu, Chak K. Chan, City University of Hong Kong, China
Abstract Number: 296
Working Group: Aerosol Chemistry
Abstract
The wide application of monoethanolamine (MEA) in post-combustion CO2 capture technology results in CO2 capture plants as a significant MEA emission source.1 As a potentially competitive MEA sink pathway in the atmosphere, the heterogeneous uptake of MEA by sulfuric acid (SA) particles via acid-base reaction might play a role in the formation of particulate MEA sulfate. We investigated the reactive uptake of ppm level MEA by sulfuric acid particles in an Electrodynamic Balance (EDB), in which the uptake changes the hygroscopicity of the particles. Hence, the hygroscopicities of MEA salts including MEA sulfate at different MEA to sulfate ratios over a wide range of RH were studied using an EDB and the Aqualab. Other salts studied include MEA oxalate, nitrate and chloride. Empirical functions were fitted to the experimentally measured hygroscopicity data of MEA sulfate of different MEA to sulfate molar ratios and applied to the analysis of composition change of the particle during MEA uptake and hence the uptake kinetics. The uptake coefficients γMEA were estimated as (3.23±0.64) ×10-3 and (9.89± 2.62)×10-4 at 40%RH and 70%RH, respectively. MEA reactive uptake by acidic particles could be competitive to gas-phase oxidation by ozone as an atmospheric MEA sink process, especially near power plants with high concentrations of fresh SA particles.
Acknowledgment
We would like to acknowledge the Hong Kong Research Grants Council (grant #11302318) for their support.
Reference
[1] Veltman, K.; Singh, B.; Hertwich, E. G. Human and Environmental Impact Assessment of Postcombustion CO2 Capture Focusing on Emissions from Amine-Based Scrubbing Solvents to Air. Environ. Sci. Technol. 2010, 44 (4), 1496–1502. https://doi.org/10.1021/es902116r.