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Kinetic studies of the pyrolysis of sewage sludge by tga and comparison with fluidized beds
Author(s) -
Dümpelmann Ralf,
Richarz Werner,
Stammbach Marc R.
Publication year - 1991
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450690418
Subject(s) - pyrolysis , fluidized bed , sewage sludge , isothermal process , thermogravimetric analysis , kinetic energy , residence time (fluid dynamics) , waste management , particle size , particle (ecology) , materials science , thermodynamics , fluidized bed combustion , fluidization , environmental science , heat transfer , chemical engineering , chemistry , environmental engineering , sewage , organic chemistry , geotechnical engineering , engineering , physics , geology , oceanography , quantum mechanics
The pyrolysis of sewage sludge was examined by thermogravimetric analysis using different heating rates, particle sizes and final temperatures. A semi‐empirical model was developed with four global consecutive/competitive reactions to volatile and solid products including also a heat balance. This model was extrapolated to isothermal reactor conditions and compared to experimental data on fluidized bed pyrolysis. Depending on the particle size and reactor temperature, about 90% of the maximum conversion in a fluidized bed takes place under external heat transfer control, the rest under kinetic control. Incomplete conversion occurs at short particle residence times, which were calculated approximately by the model.