Effects of Temperature and Catalysts on CO2 Gasification of Sawdust Charcoal
WANG Yan-jie, YING Hao, YU Wei-jin, SUN Kang
2014, 48 (3):
The effects of temperature (850, 900, 950, 1000 ℃) and catalysts (CaCO3 and K2CO3) on CO2 gasification of sawdust charcoal were investigated using thermal gravimetric analyzer and tubular reactor. Higher temperature had stimulative effect on the reactivity of sawdust charcoal reacting with CO2. With the increase of temperature from 850℃ to 1000 ℃, the CO content of gaseous product increased from 28.86 % to 54.45 %, and the heating value rised from 4.50 MJ/m3 to 7.95 MJ/m3. Meanwhile, the CO2 content decreased from 64.34 % to 36.54 %. With the sawdust charcoal sample of 2 g after gasification, the solid product decreased from 1.32 g to 0.79 g. The catalysts also had positive effects on CO2 gasification of sawdust charcoal that the CO content and heating value of gaseous product and reactivity were enhanced. And the CO2 content in gaseous product and solid product were decreased by the addition of CaCO3 and K2CO3. However, the catalytic effect of K2CO3 was more effective than that of CaCO3. The hybrid reaction model was applied to investigate the kinetics of sawdust charcoal CO2 gasification with different catalysts in this literature and the temperature range was 850-1 000 ℃. With the addition of CaCO3 and K2CO3, the activation energy and pre-exponential factor were lowered, the activation energy of charcoal without catalyst, charcoal with CaCO3 and charcoal with K2CO3 were 94.509, 81.740, 50.271 kJ/mol, and the pre-exponential factor were 1 208.428, 428.825, 19.965 min-1, respectively.
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