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56 Fossil Fuel and the Environment

Fig. 5. Measured and modelled (kinetic constants Table 2) rates of nitrous oxide emission as

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a function of time during the char combustion


Fuel-N Conversion to NO, N2O and N2 During Coal Combustion 59

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**4** 

*Czech Republic* 

Pavel Kolat and Zdeněk Kadlec *VŠB-Technical University Ostrava* 

**Co-Combustion of Coal and Alternative Fuels** 

Energy utilization of alternative fuels including biofuels is one of the main tasks for development of recoverable sources in the world. The research consists of combustion tests in the large CFB boilers and measuring data inside the combustor. Since 1995, 29 large CFB boilers of different designs and power outputs have been in operation in the Czech Republic - as shown in the Table 4. Construction of the boilers, technical documentation, licensing and engineering has been based on foreign experience. Every large power project is always preceded by trial measurements and tests on smaller pilot, trial or if need be model equipment. Due to the great difference in scale, some unexpected measuring equipment behavior or problems must be taken into consideration for co-

The present research aiming at characterising the co-combustion under-atmospheric fluidized bed conditions by different physical and chemical characteristics has the

 Recommendations for suitability of co-combustion in the atmospheric circulated fluidized bed boilers CFB and minimizing the harmful solid and gaseous emissions.

The model research has been carried out at the Technical University of Dresden. It includes the combustion tests - Table 2. - on experimental pilot equipment - Fig. 1. , 2. with atmospheric circulating fluidized bed for coal and bio-fuels produced from the sewage sludge from WWTP (waste water treatment plant) and biomass, and thermo-analytical




**1. Introduction** 

following objectives:

**2. Model research** 

combustion of coal and alternative fuels.

Ash formation upon fluidized bed co-combustion.

Fate of toxic trace metals upon fluidized bed co-combustion.

study of bio-fuels - Table 1. The modelling had the following aims:

combustion solid products (bottom ash, fly ash, deposits).

constituents (NOx, chlorine compounds, alkalis, etc.).

granulometric distribution on the process.

