| Summary: | Behavior of combustion process in the fuel bed on the grate, is
characterized by different thermochemical conversion stages, each with
significantly different temperatures, and the reacting conditions. This simple
analysis of combustion processes taking place on the grate is a useful
information for understanding of the paths of pollutants formation and
destruction as well. The large fixed bed reactor was used for obtaining the
experimental results of straw combustion. The fixed bed reactor contains a
column of biomass fuel that is ignited at the top and with air entering through
the grate from the bottom, measurements are performed while the ignition front
proceeds downwards. The influence of inlet air flow velocity and temperature,
moisture content in the fuel and oxygen concentration in the inlet air on
combustion parameters such as ignition front velocity (kg/(m2·s)), temperature,
and gas species concentration during combustion is presented based on
measurements of in-bed temperatures along the bed and different gas
compounds (O2, CO2, CO and NO) over the bed. A 1-D transient
heterogeneous model was used for straw combustion in a fixed bed. The
processes included in the model comprise: moisture evaporation, biomass
pyrolysis, heterogeneous reaction of char forming CO and CO2, homogeneous
reactions of CO, H2, CH4, CxHy and tar, heat and mass transfer between the gas
and solid phases. The model provided detailed structure of the ignition flame
front, gas species... [to full text]
|
|---|
