Study on Apparent Kinetics of the Reaction between Sulfuric and Hydriodic Acids in the Iodine–Sulfur Process
Study on Apparent Kinetics of the Reaction between Sulfuric and Hydriodic Acids in the Iodine–Sulfur Process
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DOI：
10.1002/kin.20796
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发表时间：
2013-09
影响因子：
1.5
通讯作者：
Nanqin Li;Ping Zhang;Songzhe Chen;Laijun Wang;Jingming Xu
中科院分区：
文献类型：
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作者：
Nanqin Li;Ping Zhang;Songzhe Chen;Laijun Wang;Jingming Xu
碘-硫（IS）热化学制氢是利用核反应堆提供的高温过程热最有前途的方法之一。该过程包括形成闭合循环的三个反应：本生反应，其中碘、水和二氧化硫反应形成硫酸和碘碘酸（HI）; HI分解;和硫酸分解。然而，H2SO 4和HI之间的副反应可能干扰IS闭合循环的操作。对于最佳工艺条件，应检查H2SO 4和HI之间的反应动力学。在这项工作中，进行了初步的动力学研究。采用初始反应速率法测定了硫酸与HI反应的表观反应级数和速率常数等动力学参数。对于I-，表观反应级数约为1.77，而H+和SO 42-的级数分别为7.78和1.29。在85 ± 1°C时的表观速率常数约为2.949 × 10−11 min−1（mol/L）−9.84。H+浓度对反应速率的影响比SO 42-和I-的影响更显著。这些基础数据为相关的工艺设计和进一步的动力学研究提供了有用的信息。
The iodine–sulfur (IS) thermochemical process for hydrogen production is one of the most promising approaches in using high-temperature process heat supplied by a nuclear reactor. This process includes three reactions that form a closed cycle: the Bunsen reaction, in which iodine, water, and sulfur dioxide react to form sulfuric acid and hydriodic acid (HI); HI decomposition; and sulfuric acid decomposition. However, the side reactions between H2SO4 and HI may disturb the operation of the IS closed cycle. For optimal process conditions, the reaction kinetics between H2SO4 and HI should be examined. In this work, a preliminary kinetic study was conducted. Using the initial reaction rate method, the kinetic parameters of the reaction between sulfuric acid and HI, such as the apparent reaction orders and rate constant were determined. For I−, the apparent reaction order was approximately 1.77, whereas the orders for H+ and SO42− were 7.78 and 1.29, respectively. The apparent rate constant at 85 ± 1°C was approximately 2.949 × 10−11 min−1 (mol/L)−9.84. The H+ concentration had more significant influence on the reaction rate than those of SO42− and I−. Such basic data provide useful information for related process design and further kinetics study.