Generation and characterisation of reactive and inert aerosols

J. Thieringer*, H. Werling, J. Meyer, A. Dittler, Karlsruhe Institute of Technology (KIT), Germany

Particle filters, e.g. diesel or gasoline particle filters (DPF/GPF), are applied to reduce emissions of combustion engines and have become a standard component in exhaust aftertreatment systems. The emission standards regarding particulate matter (PM) and particulate number (PN) concentrations are getting stricter hence a better understanding is essential for the optimisation of the exhaust treatment. Due to particle deposition and the resulting layer formation in the filters, the pressure drop and energy consumption increase during operation. In order to reduce these influences on the operating conditions, various process parameters and their effects on the filtration process of reactive-inert aerosols have to be identified.

To investigate the operational behaviour of cross-flow-filters, test aerosols are used to characterise the formation of particle layers and to determine structural layer changes due to break-up and rearrangement of deposited particulate matter. Due to the variety of reactive/inert aerosols, various particle size distributions (PSD) and morphologies are identified and have to be replicated. For the separation of reactive and inert particles, two different generation methods are used to produce different compositions of aerosols. The inert particles (ash) are generated with an oil-mist and a subsequent incineration in an oven. Due to the introduced oxygen, the hydrocarbons are fully oxidised to carbon dioxide and water vapour. The process parameters, oven temperature, oxygen concentration and residence time, are varied. The method for the generation of reactive particles (soot) is based on a soot generator where soot is formed with propane and a subsequent diffusion flame pyrolysis. In this process, stable operating points for the reactive particles were detected.

As expected, the inert aerosol properties, e.g. particle size and concentration, are...

Session: G8 - Short Oral Presentations
Day: 23 October 2019
Time: 14:45 - 16:00 h

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