10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Aerosol Nucleation Activated by Inducing Factors in Coal-Fired Flue Gas: A Simulation Study
CHENGSI LIANG, Chenghang Zheng, Zhengda Yang, Yi Wang, Weiguo Weng, Xiang Gao, Zhejiang University, China
Abstract Number: 741 Working Group: Aerosol Modeling
Abstract Aerosol nucleation is an important process in the formation of aerosols in flue gas from coal-fired power plants. Ultrafine particles will form in desulfurization tower because of the huge drop in temperature, which is hard to be removed and may pollute the environment. Molecule dynamics (MD) is an approaching way to study the nucleation without the huge calculated amount to get the force between different kinds of molecules and clusters. Based on the fact that the number of water molecules is much more than other kinds of molecules in the unit volume flue gas, the model of cluster, which contains one inducing molecule in the center, like a sulfuric acid molecule or charged molecule, and multilayer water molecules around it, was established. The distribution of water molecules around the center molecule were acquired by calculating the structure of clusters with different numbers of water molecules. And the force field around the cluster was acquired by calculating the change of free energy when one more water molecule move towards to the cluster. All of the above calculations were realized through the density functional theory (DFT) method. It found that, comparing to pure water vapor nucleation, the extra effects from the center molecule to the water molecules which are in the same water molecules layer are similar, and the extra effect decreases along when the layer increases until it can be ignored. Therefore, the influence of the center molecule on finite layers of water molecules was considered to simplifying the model. This simplified cluster model was used to investigate nucleation process in dynamical method. This work figured out the nucleation rate and dew point of aerosol in different conditions, which basically correspond to the acid dew point by measurement.