低温下碳气化反应的动力学研究

Kinetic Study on Boudouard Reaction of Carbon at Low Temperature

利用恒速升温热重法对低温下碳的气化反应进行了研究。结果表明:低温条件下(<1073 K)碳的气化反应符合一级反应规律;减小颗粒度可以提高碳粉的气化性能,特别是当颗粒度减小到一定程度(D50=4μm)时效果尤为显著;催化剂能够提高碳粉的气化性能,使其等动力学温度降低,特别是当细化和催化同时作用时气化反应效率更高;活性炭的气化性能优于相同粒度的石墨粉;未添加催化剂的碳粉具有相似的气化机理;Li2CO3、Na2CO3、K2CO3具有相似的催化机理。

The Boudouard reaction of carbon at low temperature was investigated by means of thermogravimetric method at constant heating rate. The gasification reaction is of the first order reaction below 1 073 K. The rate of carbon gasification is improved with particle refining, especially to a certain size （D50 = 4μm）. Isokinetie temperature is decreased with addition of catalyst. The gasification of active carbon is better than that of graphite with the same size. Catalytic mechanisms of Boudouard reaction are similar with use of Li2CO3, Na2CO3 and K2CO3 as catalysts. Mechanism of gasification of various kinds of carbon without addition of any catalyst is similar.