Combustion and Carbon Capture Technologies

About the Research Group

The research group is active within the field of combustion and carbon capture technology for power and industrial application. The research includes areas such as heat transfer and radiation in furnaces, combustion chemistry and emission formation, technologies for emission control, as well as process simulations for process and heat integration. The overall aim of the research group is to develop technologies for efficient and clean combustion processes.
 
The group has since the beginning of the 21st century carried out extensive research for development of the so called oxy-fuel combustion process that enables an easy capture of CO2, for later storage, a so called CCS technology. This is seen as one of the main options for CCS from the power and industrial sectors. Today, the group is also involved in research on technologies that capture carbon dioxide directly from a flue gas stream, so called post-combustion CO2 capture. Besides the CCS technologies the group also works on methods for controlling NOx and SOx emissions from combustion processes.
 
NOx and SOx Emissions

​The group has a long experience of technologies for control of combustion generated emissions. like nitrogen oxides (NOx) and sulphur oxides (SOx). The work includes everything from experimental work on a technical scale to modellíng of detailed combustion chemistry as well as secondary emission control in the flue gas path.

Some selected publications include:

 

The Sulphur Mass Balance in Oxy-Fuel Combustion of Lignite, Fleig et al. 2009
1st Oxy-Fuel Combustion Conference

Radiation and Heat Transfer

​The group has a long tradition within the area of measuring and modeling of radiation and heat transfer.

Some selected publications include:

Account for variations in the H 2 O to CO 2 molar ratio when modelling gaseous radiatve heat transfer with the weighted-sum-of-grey-gases model, Johansson et al 2011 Combustion and Flame

 

 

​Equipment for Experiments

​Chalmers 100 kW combustion unit

The Chalmers 100 kW test unit is one of the first test units to demonstrate the oxy-fuel combustion technology on a technical scale. The unit was taken into operation in 2003 and has since then produced high quality data for research purposes of topics like heat transfer characteristics and fundamental combustion chemistry aspects including fuel oxidation, sulphur chemistry, nitrogen chemistry.

The system is designed in a flexible way so that both air-fired and oxy-fuel fired tests can be run in the same unit with a detailed control of the heat and mass balance of the process. An advanced data acquisition system is used to sample gas composition, flow, temperature and other measurement data. A number of measurement openings are available in the reactor and at various positions in the recycle loop.

Separate injection of gases (also harmful/toxic gases) into the oxidant and/or the combustor is made possible by means of an injection system equipped with an advanced control/security system. The flue gas recycling system is designed so that both dry and wet flue gases may be recycled in the system.



​Modelling Tools

Detailed Reaction Modelling​

Detailed reaction modelling is frequently used in combustion simulations to investigate emission formation and combustion characteristics. Examples of processes investigated are NOx and SOx formation as well as interactions with alkali metals. These models typically includes up to one hundred species and one thousand reactions. The reaction kinetics are implemented to the modelling software Chemkin.​​

Process Simulations

Process simulation is a powerful tool to assess new concepts to existing processes. The figure shows an example of how CO2 capture could be integrated with a coal-fired power plant. These tools are frequently used both in PhD-projects and master theses. The group’s software portfolio includes Aspen Plus, Ebsilon Professional, and Dymola.

Fluidized Bed Modelling

The group has developed a model for circulating fluidized bed (CFB) combustion. The model includes fluid dynamics, chemistry and heat transfer and predicts critical parameters in CFB combustion, such as the external solids circulation and the distribution of the heat extraction along the circulating loop. The model is the perfect tool for designing upcoming CFB boilers. The model is semi-empirical and developed in close cooperation with the boiler manufacturer Metso Power, which provides extensive experimental data at lab (100 kW) and pilot scale (4 MW).​ ​

​Modelling of Radiative Heat Transfer

The group has extensive experience of modelling of radiative heat transfer from combustion products. The models applied account in a detailed way of the spectral radiative properties of both gases and particles including fuel, soot and ash. These models are used to evaluate and analyse experimental data, but also to study how the radiative heat transfer in combustion environments is affected of changes of the combustion conditions.​ ​

CFD Modelling

CFD-modelling is one of the tools used by the group to study combustion as a means to investigate the entire combustion process including fluid dynamics, heat transfer and fuel conversion. The research questions in focus have been the combustion chemistry and how to account for the radiative properties of the gas and particles. The modelling is carried out with ANSYS FLUENT with special models implemented as user defined functions

 

Published: Mon 28 Oct 2013.