The determination of chemicals and solids resulting from combustion processes is associated with high instrumental effort. Therefore, the group “Chemical Analytics” features state-of-the-art analytical techniques to analyze gases and particles in combustion exhausts. Focus lies on continuously recording instruments to monitor the dynamics of processes. Combustion gases, such as carbon dioxide, carbon monoxide and nitrogen oxides are measured with a mobile infrared spectrometer (FT-IR) down to the ppb-range. In addition, unburned hydrocarbons (UHC) and oxygen-containing air contaminations (e.g. formaldehyde) can be quantified. Particle emissions in the range between 2.5 nm and 10 µm can be monitored with analytical instruments that either focus on the precise size distribution of the particles or high time-resolved measurements. Furthermore, particles with diameters below 10 nm can be analyzed down to the molecular level by mass spectrometry.
The projects of the technical group mainly focus on stationary emission sources in the fields of energy and aviation (e.g. test environments for engines and reactor chambers, aircrafts on the ground, gas turbines, power plants, etc.). Suitable dilution systems with different stages allow application of the methods in a vast concentration range. The instruments for mobile campaign comprise:
Multigas FT-IR Spectrometer (FTIR, MKS)
Scanning Mobility Particle Sizer (SMPS, TSI)
Engine Exhaust Particle Sizer (EEPS, TSI)
stand-alone Condensation Particle Counter (CPC, TSI)
Optical Particle Counter (OPC, TSI)
Aerosol Photo-Ionization Mass-Spectrometer (PIMS, self-made)
Quadrupole Residual Gas Analyzer (RGA, Hiden)
Within the frame of the ECLIF project (Emission and Climate Impact of Alternative Fuels) several ground measurements were performed on the DLR research aircraft ATRA. Therewith, the impact of different modern fuels on the emission during operation could be demonstrated. Comparable measurements were also performed during the project airegEM (Aviation Initiative for Renewable Energy in Germany e.V.- Emission properties of alternative jet) at a jet engine test rig of the German Lufthansa Technik.