Förbrännings- och koldioxidinfångningstekniker

​Om Forskargruppen

Forskningsgruppen har ett brett kompetensområde inom teknik för förbränning och koldioxidinfångning inom kraft och industriprocesser. Forskningen inkluderar områden som värmeöverföring och strålning i pannor, förbränningskemi och emissionsbildning, tekniker för att reducera emissioner samt processimuleringar för process- och värmeintegrering. Det övergripande målet för forskargruppen är att utveckla tekniker för effektiva och rena förbränningsprocesser.
Sedan början av 2000-talet har gruppen genomfört omfattande forskning för att utveckla så kallad oxy-fuel förbränning (syrgasförbränning), ett av de huvudspår som finns för infångning och lagring av koldioxid från kraftverk och industriprocesser. Idag bedriver gruppen även forskning på tekniker för att absorbera koldioxid direkt från rökgasströmmar, så kallad post-combustion teknik. Förutom reducering av koldioxid jobbar gruppen även med metoder för att kontrollera utsläpp av kväve- (NOx) och svaveloxider (SOx) från förbränningsprocesser.

NOx och SOx Emissioner

Gruppen har stor erfarenhet av tekniker för reduktion av föroreningar som genereras vid förbränning, som kväveoxider (NOx) och svaveloxider (SOx). Arbetet inkluderar allt från experimentelt arbete i teknisk skal till modellering av detaljerad förbränningskemi så väll som sekundär rening i rökgasstråket.

Några utvalda publikationer inom området:

NO Emission during Oxy-Fuel Combustion of Lignite, Andersson et al. 2008
Industrial abd Engineering Chemistry Research

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

Strålning och Värmeöverföring

​Gruppen har en lång tradition inom mätning och modelering av strålning och värmeöverföring

Några utvalda publikationer inom området:

 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
 

 

Sidansvarig Publicerad: ti 27 okt 2015.