Study on the thermal stability of 2-hexyne, 1-pentyne, ethyl isocyanide, and n-butyl isocyanide as sulfur-free gas odorants

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• 作者：Yasushi Oka ; Toru Yoshida ; Takeshi Kondo ; Shunsuke Ito and Katsumi Katoh
• 关键词：Thermal stability ; Sulfur ; free odorant ; 2 ; hexyne ; 1 ; pectyne ; Ethyl isocyanide ; n ; butyl isochianide
• 刊名：Journal of Thermal Analysis and Calorimetry
• 出版年：2010
• 出版时间：January, 2010
• 年：2010
• 卷：99
• 期：1
• 页码：9-14
• 全文大小：421.2 KB

文摘

In Japan, tert-butyl mercaptan (TBM) is mainly employed as an odorant of LPG. However, the sulfur component in TBM gives the adverse effect for environment and human body and/or has a negative impact on reforming catalyst of fuel cell and other types of cogeneration systems. In this way, the development of sulfur-free odorant is expected. This study focuses on the thermal stability and combustibility of 2-hexyne, 1-pentyne, n-butyl isocyanide (BIC), and ethyl isocyanide (EIC) that is expected as the candidate odorants. As the result of DSC measurement, the comparison of T _DSC indicated that 2-hexyne and 1-pentyne are more thermally stable than BIC and EIC. However, in 2-hexyne and 1-pentyne, the slight exothermic peaks were observed at lower temperature region before those main exothermic peaks. In 2-hexyne, copper or aluminum increased the heat amount of that slight exothermic peak observed before main peak. In 1-pentyne with zinc, T _DSC was approximately decreased to 279 ¡ãC from 337 ¡ãC of 1-pentyne alone. As the results of ARC measurement, in the presence of oxygen, the exothermic heat of 2-hexyne and 1-pentyne was observed at approximately 50–100 ¡ãC. This heat release may be corresponding to the slight heat release observed by DSC, and it thought to be results from the reaction with atmospheric oxygen. In this way, for the practical application of 2-hexyne and 1-pentyne as odorants, it is important to suppress the invasion of oxygen in the cylinder to low as much as possible in respect of the storage of the candidate odorant. As a result of thermal equilibrium calculation, even if either candidate odorant is added at about 100 ppm, there is little influence on propane combustibility from the adiabatic flame temperature, species of combustion gas and their yields.