Coordinator: Dr. Peter Kutne
The use of biomass for power generation, as well as the production of liquid and gaseous fuels from biomass are important aspects in the utilization of renewable energy resources. While wind and solar power generation are subject to weather-dependent fluctuations, bio fuels can be utilized on demand in power plants and thus present an important component in the range of renewable resources. Biomass gasification is the first step in the production of (storable) fuels as well as in the direct utilization in highly efficient gas turbine cycles. In the gasification process biomass is converted at high temperature and under oxygen starvation inside a gasification reactor. Until today, the complex chemical and physical process steps are only partly understood, and the development of numerical tools and measurement techniques necessary for a detailed investigation of such processes is still in the beginning.
To optimize the gasification process and to develop new procedures, a detailed understanding of the elementary process steps inside the gasifier is required. We investigate individual process steps of the gasification process in our test rigs in order to improve the knowledge. The experimental results are used to develop numerical models describing the process.
The major goal is to simulate the whole gasification process by detailed numerical calculations and to use these numerical tools for optimization of the gasification process and for the design of gasification reactors. The numerical simulation tools are based on Large Eddy simulation (LES), partly coupled with RANS techniques (Reynolds Averaged Navier Stokes). An important aspect is the development and the implementation of chemical reaction mechanisms, which are developed and validated in house.
To validate and improve the numerical simulation tools, we are developing and adapting different optical and laser based measurement techniques for their application in technical gasification reactors. Here, the development of optical probes is a research topic of particular importance. These measurement techniques enable us to determine important process parameters like species concentration, temperature and concentration of reaction intermediates. The results provide an insight into the processes within a gasification reactor which could hardly be observed before.
This work is carried out in close cooperation with the Engler-Bunte-Institut Division Fuel Chemistry and Technology of the Karlsruhe Institute of Technology.