Аннотация:
Coal combustion remains to be one of the main energy sources in the world, despite the
agile actions towards alternative energy sources. According to International Energy Agency
demand for coal as for an energy source has been increasing since the commencement of the
technology, and yet is to escalate in the following decades. However, despite the maturity of the
coal combustion process it has some drawbacks that put this technology under debate. The main
disadvantages are emission of air pollutants (CO, CO2, NO, SO2) and low efficiency of the process,
mainly caused by coal quality. Hence a need for flexible optimization tool for the coal combustion
has emerged.
Due to numerous advantages industrial coal combustion mainly takes place in fluidized
bed reactors. Various configurations of coal combustion process have been reported up to this
point, which involved alteration of combustion environment (air/oxy-fuel), fuel type (pure
coal/blend of coal with biomass), operating pressure (atmospheric/pressurized). This work studies
aforementioned configurations and makes an attempt to develop a model capable of incorporating
these configurations without major changes in input values.
This study offers coal combustion simulation model built on Aspen Plus V11 with novel
process unit FLUIDBED (Fluidized Bed) and validated with experimental data of several
literature. The developed model has been designed taking into consideration both kinetics of the
occurring chemical reactions and hydrodynamics of fluidized bed rig. At the moment of study
completion, incorporation of fluidized bed for coal/blend fuel combustion as an individual unit in
Aspen Plus was very limited in the literature.
The study was performed by completing several consecutive stages: modelling of coal
combustion in FLUIDBED, validation of the model based on data from literature, utilization of
validated model to observe behavior of Ekibastuz coal, incorporation of biomass/coal blend fuel
into model, optimization of the process for various conditions.