Optimisation of a Condensing Wet Electrostatic Precipitator for Particulate Matter and Aerosol Separation

Project Number 337

For an economic (downstream) CO2-Separation in power plants a preconditioning of the flue gas is necessary to ensure the largely absence of residual contents of SO2, SO3, water and dust. Within the scope of this method, commonly known as Capture-Ready-Design, the extension of the conventional flue gas treatment by including a condensing wet electrical precipitator appears to be a promising approach.

The objective of the project is to design concepts for industrial applications based on the examination of a wet electrostatic precipitator capable to scale-up and the development of corresponding simulation software. For this purpose precipitation rates of particles with varying diameters and concentrations will be determined by measuring the relevant parameters at the inlet and outlet of the experimental ESP. Before entering the ESP a conditioning of the used medium takes place. Proceeding in this way with an additional variation of parameters such as the electric potential and the flow velocity enables the characterization of a wide spectrum of operating conditions.

A CFD-model shall be developed simultaneously to the experiments. The achieved results of the experiments shall be used to validate the model. Considering the already mentioned parameters in a numeric model based on physical relations implies a significant improvement regarding the dimensioning of wet electrical precipitators. Previous design principles depend on the approval of a constant and therefore a fictitious velocity of particles migration towards the separating surface. The water vapor saturated atmosphere and the presence of aerosols behind a flue gas desulphurization plant make it difficult to proof the adequacy of the application of a wet electrostatic precipitator designed in that way. The CFD-model to be developed represents therefore an innovative method for dimensioning and optimizing wet electrostatic precipitators for industrial applications.

The research project has been put in execution since May 2010 for a period of two years. Responsible for the construction of the testing plant and the execution of the experiments is the Institute of Energy and Environmental Technology  in Duisburg. The CFD-model for simulation of the precipitation process of the condensing wet electrostatic precipitators will be developed at the Chair of Environmental Engineering at the Technical University of Dortmund. 

The project is funded by the German Federal Ministry of Economics via the AiF (funding no. 16563 N). It is supervised by the Working Panel Flue Gas Cleaning Technology.