Burner Development for High Pressure Entrained Flow Gasification

High pressure entrained flow gasification, where low-grade anthropogenic and biogenic fuels are converted into a high quality syngas (CO + H2), is one of the key enabling technologies for a future circular economy and a sustainable use of resources. The syngas subsequently can be used for the synthesis of chemicals or serve as fuel in an IGCC power plant. To guarantee for complete conversion of those low-grade fuels, as well as for a high quality syngas (no soot or residual hydrocarbons), the droplet size and the related flow field, generated by the burner nozzle of the gasifier, play a major role. A variety of experimental investigations focused on atomization and gasification is essential for the design and development of a suitable burner nozzle.
The present study is focused on the development steps, necessary for the design of a new high-pressure entrained flow gasifier burner nozzle, applicable for the gasification of low-grade anthropogenic fuels. Experimental investigations focused on liquid mass flow scaling of gas-assisted atomizers are presented, to get a deeper insight into one step of the burner design process.
Typically, spray investigations are performed at lab scale, featuring only low liquid mass flow rates, thus knowledge concerning mass flow scaling of gas-assisted burner nozzles towards industrial throughput range is scarce. ... mehrTo overcome this weakness experimental investigations, focused on liquid mass flow scaling were performed. An approach keeping the most important characteristic numbers constant – which are in terms of atomization Weaero and GLR – while increasing the liquid mass flow in the steps 20 / 50 / 100 / 500 kg.h-1 was chosen. One specific nozzle was designed for each mass flow step. Spray investigations concerning primary breakup, as well as resulting droplet size in terms of Sauter Mean Diameter (SMD) were performed. Finally a correlation for liquid mass flow scaling was derived out of the experimental data, allowing for nozzle design for a target SMD.
Accompanying gasification experiments were performed at atmospheric pressure, to estimate the influence of the spray on the flame position and morphology.
Additional research work aims to combine the knowledge about mass flow and pressure scaling of nozzles with the interdependence between nozzle geometry, flame position and syngas composition. This finally leads to design criteria for burner nozzles, suitable for high pressure entrained flow gasification of low grade fuels.