The technical group chemical analytics is dealing with topics in the fields of (alternative) fuels, air pollutants, exhaust analytics and combustion chamber systems. Here, regular techniques of instrumental analysis are combined with self-developed methods, like, e.g. the molecular beam mass spectrometry (MBMS), and are applied for current technical and scientific challenges. Within the cross-section between the departments for chemical kinetics, multiphase flows, and combustion diagnostics the group deals with combustion-related analytical questions from basic science to the technical application.
The analytical tasks cover interdisciplinary fields with focus on:
In order to assess the suitability of modern fuels for selected application fields they are analyzed via gas chromatography coupled with mass spectrometry. This allows precise determination of the chemical composition. The overall evaluation is, then, possible via the combination with important physical properties of the fuel.
The basic processes during the combustion of a certain fuel or selected components can be analyzed by the use of a high temperature flow reactor at well-defined conditions. The intermediary species occurring in the flame can be precisely determined via molecular beam mass spectrometry. The profiles of different species allow systematic conclusions on the underlying chemical reactions and even on the expected compounds in the exhaust stream.
In 2013 a pioneer experiment in cooperation with partners from Switzerland and the University of Duisburg/Essen allowed further insight into the reaction chemistry in a flame. The applied photoelectron photoion coincidence spectroscopy (PEPICO) at the Swiss Lightsource (SLS) of the Paul Scherer Institute allowed a detailed characterization of combustion processes.
The monitoring of exhaust gas components (field measurements, test rigs, flow reactor) can be performed with a variety of different online techniques. Here, special focus lies on the combustion gases (e.g. carbon dioxide, carbon monoxide, nitrogen oxides) and also particle emissions. With respect to airborne particles, different methods are available that either focus on the dynamics of the aerosol release process or the precise determination of the particle size distribution in the range from 2,5 nm to 10 µm.
Overall, the activities of the technical group aim at the reduction of air pollutant release during combustion processes (e.g. by substitution and optimization of fuels). The scope of the group allows the analytical support of the scientific core topics of the institute and span from fuel characterization, basics chemical conversion processes to the resulting emissions from real technical combustion engines.