金属复合催化剂对煤气化的暂态动力学研究

采用阶跃扰动技术进行了金属复合催化剂对煤气化的暂态动力学研究。根据实验结果推导得出了该反应过程是催化剂表面富氧活性部位先与煤焦反应生成一个CO分子，然后此CO分子从催化剂表面脱附，接着催化剂吸附气态的CO2生成一个CO并且夺得一个氧原子实现自身还原的过程，在此基础上建立了煤的催化气化的物料平衡方程组，对各步骤的反应速率常数进行了求解，在本文采用的实验条件下，各反应步骤的反应速率常数分别为0.0703 mol·g-1·min-1·kPa-1;0.0959 mol·g-1·min-1·kPa-1;0.00539 mol·g-1·min-1·kPa-1;0.0321mol·g-1·min-1·kPa-1。由此得出了该反应历程的控制步骤为CO2的吸附步骤等历程信息。

STUDIES ON CARBON GASIFICATION KINETICS WITH THE CATALYSIS OF METAL COMPOUNDS BY USING TRANSIENT TECHNIQUES

The step-response transient kinetics techniques have been used for the exploration of the carbon gasification mechanism with the catalysis of metal compounds. According to the experimental results the reaction mechanism of gasification is proposed: firstly, the catalyst releases an oxygen atom from its rich-oxygen site to combine with a carbon atom and create a CO, then the CO molecule desorbs from the catalyst surface; next, the catalyst absorbs a CO2 molecule; and finally on the catalyst surface another CO molecule is created and the original rich-oxygen site gets an oxygen atom. On the basis of gasification process the material balance equations were built, which were solved by using numerrical integral methods and the reaction rate constants for four steps were obtained: they are 0.0703mol·g-1·min-1·kPa-1, 0.0959mol·g-1·min-1·kPa-1, 0.00539 mol·g-1·min-1 and 0.0321 mol·g-1·min-1·kPa-1 respectively. It can be concluded that the absorption of CO2 onto the catalyst is the control step of gasification process.