Xie Yu, Zhang Yanqiong, Zhuang Chunji, Hu Xuyong, Zhao Yinke, Huang Hui, Dong Ziwen
Ningbo University of Technology, Ningbo, Zhejiang 315211, China.
Zhejiang Institute of Tianjin University, Ningbo, Zhejiang 315201, China.
ACS Omega. 2023 Jul 28;8(31):28758-28768. doi: 10.1021/acsomega.3c03568. eCollection 2023 Aug 8.
The dilution inerting process of multi-component flammable gaseous mixtures is an important emergency disposal technology that has been widely applied in the explosion-proof field of flammability gases (vapors). In this study, we examined the flammability limits (LFLs and UFLs) of mono and binary alkane mixtures of methane, ethane, and propane when nitrogen is used for dilution inerting. The HY12474B explosion limit test device was used to determine the flammability limits, and the obtained data were compared with the literature data and Chatelier's law. Additionally, the sensitivity coefficient of the chemical reaction chain for LFLs and UFLs of the binary alkane mixtures was analyzed. The minimum inerting concentration (MIC) of methane was found to be sequentially higher than that of ethane and propane when using nitrogen for dilution inerting, and the MIC of the binary alkane mixtures follows the rule of methane/ethane > methane/propane > ethane/propane. Chemical kinetics calculation revealed that the maximum positive sensitivity coefficient of methane/ethane, methane/propane, and ethane/propane are both R5 H + O ↔ O + OH, and the reaction with the maximum negative sensitivity coefficients are both R34 H + O(+M) ↔ HO(+M) and R43 CH + H(+M) ↔ CH(+M), respectively. The limiting oxygen concentration (LOC) for both mono alkane and binary alkane mixtures ranged between 10 and 13%. The region of the triangular flammability diagram for methane and ethane was greater than the regions for methane/ethane and methane/propane. In contrast, propane had a smaller region compared to other mono alkane or binary alkane mixtures.
多组分可燃气体混合物的稀释惰化过程是一项重要的应急处置技术，已在可燃气体（蒸气）防爆领域得到广泛应用。在本研究中，我们考察了用氮气进行稀释惰化时甲烷、乙烷和丙烷的单组分及二元烷烃混合物的可燃极限（下限和上限）。使用HY12474B爆炸极限测试装置测定可燃极限，并将所得数据与文献数据及查特里尔定律进行比较。此外，还分析了二元烷烃混合物可燃下限和上限的化学反应链敏感系数。发现用氮气进行稀释惰化时，甲烷的最小惰化浓度依次高于乙烷和丙烷；二元烷烃混合物最小惰化浓度遵循甲烷/乙烷＞甲烷/丙烷＞乙烷/丙烷的规律。化学动力学计算表明，甲烷/乙烷、甲烷/丙烷和乙烷/丙烷的最大正敏感系数均为R5 H + O ↔ O + OH，最大负敏感系数的反应分别为R34 H + O(+M) ↔ HO(+M)和R43 CH + H(+M) ↔ CH(+M)；单组分和二元烷烃混合物的极限氧浓度（LOC）在10%至13%之间；甲烷和乙烷的三角形可燃图区域大于甲烷/乙烷和甲烷/丙烷的区域；相比之下，丙烷的区域比其他单组分或二元烷烃混合物的区域小。
