Determination of intrinsic rate constants of the CaO–CO2 reaction
Determination of intrinsic rate constants of the CaO–CO2 reaction
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DOI：
10.1016/j.ces.2007.08.055
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发表时间：
2008
影响因子：
4.7
通讯作者：
P. Sun;J. Grace;C. Jim Lim;Edward J. Anthony
中科院分区：
文献类型：
--
作者：
P. Sun;J. Grace;C. Jim Lim;Edward J. Anthony
用常压热重分析仪(ATGA)和加压热重分析仪(PTGA)研究了两种脱硫剂的CaO-CO2反应速率常数。用颗粒模型确定了速率控制步骤。本征反应速率与CO_2分压呈不同的级数关系，当CO_2分压超过∼10kPa时，一级反应变为零级。在加压条件下，没有观察到进一步的速率提高，这是由两步Langmuir机制解释的。测得石灰石和白云石的活化能分别为29±4和24±6kJ/mol。
The rate constant of the CaO–CO2reaction was studied for two sorbents using an atmospheric thermogravimetric analyzer (ATGA) and a pressurized thermogravimetric analyzer (PTGA). A grain model was used to determine the rate-controlling steps. The intrinsic rate was found to have a variable order with respect to CO2partial pressure, with a first-order reaction changing to zero-order dependence when the CO2partial pressure exceeded ∼10kPa. No further rate enhancement was observed under pressurized conditions, which was explained by a two-step Langmuir mechanism. The activation energies were 29±4 and 24±6kJ/mol for the limestone and dolomite tested.