ABSTRACT
Gasification process is being developed to produce a clean and efficient gas flue from fuels such as coal, biomass, and solid/liquid wastes for power generation. In this work, a biomass gasification kinetic model that can predict reaction temperature, gasification performance, and gas composition has been developed for a circulating fluidized bed (CFB). Experimental data from a CFB power plant have been used to validate the model. It is confirmed that the addition of steam is important for increasing the hydrogen concentration and syngas caloric value. Based on the predicted results, an optimal condition is suggested for air and steam gasification in the CFB gasifier.
KEYWORDS:
Nomenclature
a | = | decay constant (dimensionless) |
Ar | = | Archimedes number (dimensionless) |
dp | = | particle diameter (mm) |
Dr | = | riser internal diameter (m) |
Ee | = | energy from energetic components (MJ) |
Ef | = | energy from feedstock (MJ) |
g | = | acceleration due to gravity (m/s2) |
Ug | = | superficial gas velocity (m/s) |
Umf | = | minimum fluidization velocity (m/s) |
Ut | = | terminal particle velocity (m/s) |
y | = | axial distance from the distributor (m) |
yd | = | height of the dense bed in the riser (m) |
Greek symbols
= | solids holdup | |
= | solid holdup in the dense bed of the riser | |
= | solid holdup at uniform flow | |
= | cross-sectional average solids holdup at dilute region | |
= | gas viscosity (Pa s) | |
= | gas density (kg/m3) | |
= | particle density (kg/m3) | |
= | solid circulation rate (kg/m2s) |
Acknowledgement
This work was partly supported by key funding projects for visiting scholars of Research Center for Social Development in Rural Areas of Anhui University (No. 2016cxy001).