TY - JOUR
T1 - SO3 formation under oxy-CFB combustion conditions
AU - Duan, Lunbo
AU - Duan, Yuanqiang
AU - Sarbassov, Yerbol
AU - Li, Yanmin
AU - Anthony, Edward J.
N1 - Funding Information:
The authors gratefully acknowledge financial support of this research by the National Natural Science Foundation of China ( 51206023 ).
PY - 2015/12/1
Y1 - 2015/12/1
N2 - Due to the enrichment of SO2 and H2O, SO3 formation during oxy-fuel circulating fluidized bed (CFB) combustion may significantly increase over the air fired case and this requires special attention in terms of safety consideration. In an attempt to better elucidate the formation mechanism of SO3 under oxy-fuel CFB conditions, homogenous and heterogeneous experiments were performed using a small vertical tube reactor to model the SO3 formation condition in the back pass channels and then the mechanism deduced was further validated by tests and measurements using a pilot-scale 50kWth oxy-fuel CFB combustor with wet flue gas recycle. Results show that replacing N2 by CO2 does not change the SO3 formation levels while the addition of water enhances SO3 formation. The increased O2, SO2, H2O concentrations along with increasing temperature are favorable for enhancing SO3 formation over the range of tested parameters. Fe2O3, CuO and V2O5 are shown to be able to catalyze SO2 conversion to SO3 under oxy-fuel atmosphere; of these V2O5s catalyzing ability is the strongest. Fly ash can either catalyze the SO3 formation or absorb SO3, depending on the temperature and the alkalinity of the ash. The results from the pilot plant burning bituminous coal demonstrate that SO3 concentration in the flue gas is about 4.5 times higher during oxy-fuel combustion than that under air combustion.
AB - Due to the enrichment of SO2 and H2O, SO3 formation during oxy-fuel circulating fluidized bed (CFB) combustion may significantly increase over the air fired case and this requires special attention in terms of safety consideration. In an attempt to better elucidate the formation mechanism of SO3 under oxy-fuel CFB conditions, homogenous and heterogeneous experiments were performed using a small vertical tube reactor to model the SO3 formation condition in the back pass channels and then the mechanism deduced was further validated by tests and measurements using a pilot-scale 50kWth oxy-fuel CFB combustor with wet flue gas recycle. Results show that replacing N2 by CO2 does not change the SO3 formation levels while the addition of water enhances SO3 formation. The increased O2, SO2, H2O concentrations along with increasing temperature are favorable for enhancing SO3 formation over the range of tested parameters. Fe2O3, CuO and V2O5 are shown to be able to catalyze SO2 conversion to SO3 under oxy-fuel atmosphere; of these V2O5s catalyzing ability is the strongest. Fly ash can either catalyze the SO3 formation or absorb SO3, depending on the temperature and the alkalinity of the ash. The results from the pilot plant burning bituminous coal demonstrate that SO3 concentration in the flue gas is about 4.5 times higher during oxy-fuel combustion than that under air combustion.
KW - Homogeneous and heterogeneous reactions
KW - Oxy-fuel CFB combustion
KW - Pilot-scale testing
KW - SO formation
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U2 - 10.1016/j.ijggc.2015.10.028
DO - 10.1016/j.ijggc.2015.10.028
M3 - Article
AN - SCOPUS:84947804109
SN - 1750-5836
VL - 43
SP - 172
EP - 178
JO - International Journal of Greenhouse Gas Control
JF - International Journal of Greenhouse Gas Control
ER -