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Download fileSequestration of Flue Gas CO2 by Direct Gas–Solid Carbonation of Air Pollution Control System Residues
journal contribution
posted on 2012-12-18, 00:00 authored by Sicong Tian, Jianguo JiangDirect gas–solid carbonation reactions of residues from
an air pollution control system (APCr) were conducted using different
combinations of simulated flue gas to study the impact on CO2 sequestration. X-ray diffraction analysis of APCr determined the
existence of CaClOH, whose maximum theoretical CO2 sequestration
potential of 58.13 g CO2/kg APCr was calculated by the
reference intensity ratio method. The reaction mechanism obeyed a
model of a fast kinetics-controlled process followed by a slow product
layer diffusion-controlled process. Temperature is the key factor
in direct gas–solid carbonation and had a notable influence
on both the carbonation conversion and the CO2 sequestration
rate. The optimal CO2 sequestrating temperature of 395
°C was easily obtained for APCr using a continuous heating experiment.
CO2 content in the flue gas had a definite influence on
the CO2 sequestration rate of the kinetics-controlled process,
but almost no influence on the final carbonation conversion. Typical
concentrations of SO2 in the flue gas could not only accelerate
the carbonation reaction rate of the product layer diffusion-controlled
process, but also could improve the final carbonation conversion.
Maximum carbonation conversions of between 68.6% and 77.1% were achieved
in a typical flue gas. Features of rapid CO2 sequestration
rate, strong impurities resistance, and high capture conversion for
direct gas–solid carbonation were proved in this study, which
presents a theoretical foundation for the applied use of this encouraging
technology on carbon capture and storage.