Low temperature chemistry of novel bio-hybrid fuels

The fundamental research in the Cluster of Excellence “The Fuel Science Center – Adaptive Conversion Systems for Renewable Energy and Carbon Sources” (FSC) aims to integrate renewable electricity with the joint utilization of bio-based carbon feedstocks and CO2 to provide high-density liquid energy carriers (“bio- hybrid fuels”), which enable innovative engine concepts for highly efficient and clean combustion.

An important criterion for the evaluation of fuels is the ignition behavior. In addition to the normal high-temperature chemistry, many fuels show specific reaction pathways at low temperatures. While only low temperature combustion (T < 900 K) rarely occurs, combustion in diesel engines, for example, passes through areas where low temperature conditions prevail. Produced by low-temperature chemistry, the reactive intermediates formed in this area have a strong influence on the general ignition behavior of the fuel.

With the aid of experimental measurements, existing and new detailed reaction models can be analyzed and further developed to support the simulation of diesel-like fuels. For this purpose, a laminar flow reactor in combination with a gas chromatography-mass spectrometry device (GC-MS) is used within the framework of these fundamental investigations. In the laminar flow reactor, ignition delay times - the time interval for the auto ignition of a fuel under given conditions - are obtained in the low temperature region. After ignition, heat losses freeze chemical reactions and stable intermediate species are conserved. These species are subsequently sent to the GC-MS for identification and quantification.