10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Understanding Particulate Matter Formation in CO2 Capture Plants using Molecular Dynamics Simulation
MEHDI AMOUEI TORKMAHALLEH, Mansurov Ulan, Dhawal Shah, Chemical and Aerosol Research Team, Nazarbayev University
Abstract Number: 189 Working Group: Aerosol Modeling
Abstract Carbon capture has been proposed as a viable method that is capable to reduce CO2 emissions from power plants by 80 % to 90 %. The most advanced method in terms of industry is post-combustion CO2 capture (PCCC) using aqueous monoethanolamine (MEA) as a solvent. However, a major factor that precludes its widespread implementation is the high cost of the process, which is largely conditioned by substantial solvent losses during the process. These losses have been strongly linked to formation of aerosols or particulate matter (PM). Due to recent emergence of the issue, formation of aerosols (PM) has been an object of only few studies. Several efforts were made to model PM formation and behavior using commercial software such as ASPEN PLUS and MATLAB. Nevertheless, since these programs cannot model nucleation process, the attempts possess certain fundamental shortcomings. This original research aims to address the issue of PM formation in a PCCC absorption column at a molecular level using molecular dynamics simulation. The simulations were carried out using GROMACS software. Five different systems were considered including various configuration of components. Clustering effect of molecules has been observed in four systems out of five. Essentially, these molecular clusters are PM that emerge as a separate phase in the gas phase. Nucleation rate of the PM were in the order of 10-30 cm-3s-1 in all systems. In the systems with one condensable component PM formation was governed by saturation ratio. On the contrary, in the systems with several condensing components nucleation process was observed even if the gas phase was slightly sub-saturated. Special emphasize was made on interaction energies between participating components which drive the formation of PM. Inferred from simulation results, strong short-range attraction energy was reveled between water and CO2 and between water and MEA. Furthermore, radial distribution analyses were performed to examine the structure of formed PM. Based on the findings of the study certain practical suggestions were offered to decrease the formation rate of PM in a PCCC column.