Oxyflame: Combustion without air

Conventional power plants use air to burn fossil fuels such as biomass, coal or gas. With oxyfuel processes, on the other hand, the fuel is burnt with a mixture of oxygen and flue gas, whereby the flue gas consists mainly of water vapour and CO2. The water vapour is captured as water by cooling the flue gas. Additional downstream processing stages bring the purity of the remaining carbon dioxide to values required for food production. This almost completely pure carbon dioxide can either be further deployed or stored in underground storage facilities where the CO2 cannot harm the climate.

However, the details behind the processes undergone during oxyfuel combustion are still insufficiently known. Scientists at RWTH Aachen University, Ruhr-Universität Bochum and TU Darmstadt have therefore combined together to form the Transregio Oxyflame special research area – which has been recently approved by the German Research Foundation (DFG) – in order to close this knowledge gap.

The Oxyflame project is concerned with the “development of methods and models for describing the reaction of solid fuels in an oxyfuel atmosphere”. Scientists at a total of 13 institutes are investigating in an interdisciplinary manner the processes that occur on individual particles, particle clouds and in the entire combustion chamber. They therefore want to develop models for the oxyfuel combustion for different fuels such as biomass and coal.

Parallel to this, they are also determining basis data for predicting the heat transfer between the flame, combustion chamber and their components. The data is intended to provide a basis for both the model development as well as for developing new burners and combustion chambers. Because the industrial production has still been strongly based on experiments until now, the design methodology developed in the project will enable, for example, burners to be optimised more quickly and therefore more cheaply. The methodologies developed in the Oxyflame project will for the first time enable the targeted and reliable design of oxyfuel power plants.