Detailed Experimental Analysis of Flow Field and Flame Structure in an Entrained Flow Gasifier - Insights into Reaction Zones in Liquid Fuel Gasification

High pressure entrained flow gasification is an efficient technology for the production of a high quality syngas, with minimum amount of hydrocarbons, tar and soot. A broad range of solid, liquid, and suspension fuels can be used. Especially for suspension fuels, e.g. slurries consisting of pyrolysis oil and char as applied in the bioliq® process at KIT, the gasification process is characterized by complex interactions and overlapping of different physical and thermo-chemical process steps. The interaction of these processes in the flame zone is crucial for fuel conversion, understanding their complex interactions is essential for design and operation of entrained flow gasifiers. This work presents a detailed experimental investigation on the burner near flow field, fuel spray characteristics and flame structure in a bench scale entrained flow gasifier. Experiments were carried out at the Research Entrained flow Gasifier REGA at KIT under atmospheric pressure conditions. The reactor has optical access ports on 4 levels and a movable burner plate, which allows a detailed optical investigation of the flame zone in a range of 0 – 300 mm from the nozzle exit. ... mehrMono ethylene glycol was used as surrogate fuel, which was fed to the reactor by an external mixing twin fluid nozzle. The fuel was gasified with oxygen enriched air at an adiabatic reaction temperature of 1700 °C. Data on flame structure was obtained by measuring OH*-chemiluminescence, temperature profiles were measured after the flame
zone. Axial and radial profiles of droplet velocity were measured by PDA. Results from the gasification experiments are discussed in comparison to spray experiments at ambient conditions. The results give insight into the conversion of liquid fuels under gasification conditions as well as the oxidation processes
in the burner near region, both relevant for the formation and decomposition of intermediates and thus for design and operation of technical entrained-flow-gasifiers.