The department of Chemical Kinetics is combining experiments and numerical simulations for an improved understanding of the combustion of alternative fuels such as biogenic gas mixtures, hydrogen rich synthetic gases, alcohols, synthetic kerosenes, as well as CO2 reduction. Our studies are addressing characteristic combustion properties of any fuels such as self-ignition, heat release, and flame quenching, as well as the formation of pollutants. The focus is on the use of these fuels in modern gas turbines and engines, mostly for power production.
Alternative fuels stem from a variety of feedstock: Solid fuels such as wood, biogenic waste and by-products; liquid fuels such as bio-alcohols from renewable feedstock and synthetic kerosenes (BtL, GtL, SPK, ATJ, etc.); gaseous fuels such as bio-methane produced e.g. from fermentation process from plants, synthetic gases from the gasification of biomass, and hydrogen.
As an example, biogenic gas mixtures are consisting of different amounts of hydrogen, carbon monoxide, methane, nitrogen, carbon dioxide, and water, depending on the specific feedstock and the specific gasification process. Hydrogen is characterized by a large laminar flame speed, a wide range of ignition, and a high adiabatic flame temperature. Due to the high reactivity of hydrogen, the ignition behavior of synthetic gases which are composed by hydrogen as a major component must be investigated in detail to rule out damaging of the burner or even the gas turbine due to a possible self-ignition or a flash back.
Presently, the combustion behavior of these alternative product gases is not sufficiently known to guarantee a reliable and safe operation in gas turbines and engines as well as in fuel cells because of the large variation in their specific composition. A broad experimental data base is needed to utilize the potential of alternatives fuels, with respect to power generation as well as a road transport and aviation fuel. Questions related to fuel flexibility, use in different types of facilities - centralized and decentralized (micro gas turbine) – are addressed. Values of the laminar flame speed and ignition delay times are measured in the relevant operating parameter range - high pressure, high temperature, and varying fuel air ratio among them.
Furthermore, detailed chemical kinetic reaction mechanisms are be developed, validated, and optimized by the comparison with the experimental data sets. These reaction models allow a reliable description and prediction of characteristic combustion properties for a variety of operation parameters. Subsequently, simplified reaction models can be elaborated which are essential for predictive numerical simulations (CFD calculations).