Abstract: The article reveals the spontaneous ignition characteristic of activated carbon(AC)as well as its key influencing factors in order to avoid or reduce the spontaneous ignition risk of AC in the process of storage and transportation.The AC samples were successfully prepared with cottonwood powder as carbon precursor and zinc chloride as activated agent at temperature from 300℃ to 700℃,and the variation of spontaneous ignition temperature with the activation temperature was also investigated.The microstructure and surface functional groups of AC samples were characterized by X-ray diffraction(XRD)and Fourier transform infrared(FT-IR)spectra and the thermostability was studied by simultaneous thermal analyzer(STA).The results show that activation temperature has a great influence on the spontaneous ignition temperature of AC samples.Spontaneous ignition becomes easier if decreasing the activation temperature,which is attributed to the gradual increase of the quantities or varieties of surface functional groups of AC.It is also confirmed that the DSC and TG curves of the AC samples tend to shift to the high-temperature region with the activation temperature increasing.In other words,a higher activation temperature in the preparation process is beneficial to reduce the spontaneous ignition risk of AC.

Key words: activated carbon, activation temperature, spontaneous ignition temperature, surface functional group

摘要： 研究揭示活性炭的自燃性质及其关键影响因素,有助于避免和降低活性炭在储运过程中的自燃危险性。以杨木粉为原料,氯化锌为活化剂,在300~700℃活化温度下制备了活性炭,并考察了自制活性炭的自燃温度随活化温度的变化规律。用X射线衍射和傅里叶红外光谱研究了样品的微观结构及表面官能团特征;用STA同步热分析仪研究了活性炭的热稳定性。研究表明,活化温度对活性炭自燃性有显著影响;活化温度越低,活性炭表面官能团种类越多、含量越大,越容易自燃;随活化温度的升高,活性炭的DSC和TG曲线均向高温区移动,活性炭趋于稳定,不易自燃。适当提高活化温度,有利于降低活性炭的自燃危险性。

关键词: 活性炭, 活化温度, 自燃温度, 表面官能团