(58y) A New Model to Predict MEA Loss through Particulate Phase (Aerosol)  in Post Combustion CO2 Capture Plants Using Aspen Plus

Authors: 
Amouei Torkmahalleh, M., Nazarbayev University
Galymzhanov, N., Nazarbayev University
The Monoethanolamine (MEA) aqueous solution is widely used as a solvent for absorbing CO2. One of the disadvantages of MEA is that exceedingly high amount of energy is required which causes loss of overall efficiency of power plants. Moreover, regardless of solvent mechanical loss, the solvent loss due to evaporation and particulate phase emissions is another issue that results in negative environmental effects and increase of the total operational cost. Experimental studies on PM measurements in PCCC columns are scarce in the literature, necessitating developments of simulation and modeling studies in this field. However, prediction of particle formation in PCCC columns is a complex task requiring modeling of several steps including gas-phase supersaturation, particulate matter (PM) formation (nucleation) and PM dynamics (growth and loss). Preexisting PM introduced by combustion fumes into PCCC facilitates formation of new particles as a result of gas phase supersaturation. Hence, developing a simulation tool to understand the key parameters affecting the supersaturation of the gas phase in PCCC columns is of paramount importance. Few attempts were made to setup a simulation tool using Aspen Plus simulator to predict supersaturation of gas streams in PCCC columns in the absence of particulate phase [14], and in the presence of combustion generated PM in the flue gas.[15] However, such simulation models still need to be improved to better understand the interactions between the particulate phase and other phases inside the column. In the current study a new conceptual model based on the film theory was developed to study interaction between the particulate matter and the gas and the solvent flows inside an absorbing column. The new model gives opportunity to study aerosol emission exiting from the absorber column, i.e. its flowrate and composition, and factors that have influence on it. Aspen Plus V9.0 software was used to model the system. An absorber column, and solvent and flue gas inlet parameters were taken from a pilot plant study at the University of Texas at Austin. The current model enable us to distinguish between the MEA loss through particulate phase and the gas phase. The results show an increase in particle size at the top of the column which could be due to the condensation of materials on the surface of the existing particles inside the column. The glue gas becomes supersaturated at the top of the column due to the rapid cooling. Further results will be presented during the AIChE meeting.