473100 Simulation of Gas Phase Supersaturation and Particulate Matter Formation in Post Combustion CO2 capture Plants Using Aspen Plus

Tuesday, November 15, 2016: 12:30 PM
Mission I (Parc 55 San Francisco)
Mehdi Amouei Torkmahalleh, Meiirbek Islamov, Yenglik Kenges and Nurlan Karimzhanov, Chemical Engineering, Nazarbayev University, Astana, Kazakhstan

Over the past years CO2 emission reducing technologies were widely investigated due to alarming climate change, particularly, global warming. One of the most promising and perspective methods for capturing CO2 is applying Carbon Capture and Storage (CCS) of flue gases using reactive absorption based Post Combustion CO2 Plants. One of the most popular solvents for absorbing CO2 is a 30 wt.% aqueous solution of the monoethanolamine (MEA). Apart from mechanical losses, solvent loss due to evaporation and particulate matter (PM) phase emissions result in the increase in total operational cost and environmental impact. Prediction of PM formation in PCCC columns is a complex task requiring modelling of several steps including gas-phase supersaturation, PM formation (nucleation) and PM dynamics (growth and loss). Pre-existing PM into PCCC columns facilitates formation of new particles as a result of gas phase supersaturation. Hence, developing a simulation tool to understand the key parameters impacting 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, and in the presence of the flue gas PM. 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 a recent study, equilibrium between the gas phase and the PM phase along the absorption column was assumed. However, the true mass and heat transfer between the particulate phase and gas phase need to be determined using a nonequilibrium (rate-based) model. The objective of this study is to firstly implement a rate-based model in Aspen plus to simulate cocurrent interactions between gas phase and particulate phase. The simulation results are validated using experimental data available in the literature. Then using the developed model, sensitivity analysis is perfomred to understand the effect of different operating conditions on MEA loss through the PM phase. Our preliminary data show that the gas and particulate phases reach equailibrium along the given absorption column, and also MEA losses through PM phase is comparable to the MEA loss through the gas phase.

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