Changes in the reaction regime during low-temperature oxidation of coal in confined spaces |
| |
Authors: | Yulong Zhang Jianming Wu Liping Chang Junfeng Wang Zhengfeng Li |
| |
Institution: | 1. Key Laboratory of Coal Science and Technology, Taiyuan University of Technology, Ministry of Education and Shanxi Province, Taiyuan 030024, People''s Republic of China;2. College of Mining Technology, Taiyuan University of Technology, Taiyuan 030024, People''s Republic of China |
| |
Abstract: | A study of the initial stage of the low-temperature oxidation of coal is important, not only for the prevention for fires in coal industry, but also in reducing emissions of hazardous gases. A batch reactor was introduced and a series of simulated experiments of coal oxidation was carried out in this paper. The time-dependent rates of CO emission and oxygen consumption during oxidation experiments of coal samples with different particle size ranges were obtained simultaneously from the measurements of CO and O2 concentration in the reactor. The experimental results show that the rate of CO emission presents three stages in the duration of coal oxidation. Based on the rates of oxygen consumption, the reaction order and reaction rate were obtained from the reaction rate equation. These results indicate that the reaction regime switches during coal oxidation in confined spaces. The initial decrease of reaction rate is due to the decrease of the active sites in coal. While the decrease of reaction rate in the following period of coal oxidation is attributed to the reaction-inhibition mechanism of oxidation products. And it is mainly represented by the chemisorption sequence of coal oxidation. The oxidative activity of coal can be restored when the oxidation products are evacuated. A mechanism of low-temperature oxidation of coal in confined spaces was also suggested. |
| |
Keywords: | Coal Low-temperature oxidation Reaction regime Confined spaces |
本文献已被 ScienceDirect 等数据库收录! |