关键词: 木屑炭, 二氧化碳气化, 温度, 催化剂, 动力学

Abstract: 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.

Key words: sawdust charcoal, CO₂ gasification, temperature, catalyst