Li Qing-En, Zhang Bing J, Lyu Shu-Shen, Qi Zhiwen
School of Materials Science and Engineering, Guangdong Engineering Center for Petrochemical Energy Conservation, The Key Laboratory of Low-carbon Chemistry & Energy Conservation of Guangdong Province, Sun Yat-Sen University, Xiaoguwei Island, Panyu District, Guangzhou 510006, P. R. China.
Max Planck Partner Group at the State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China.
ACS Omega. 2023 Aug 29;8(36):32752-32764. doi: 10.1021/acsomega.3c03563. eCollection 2023 Sep 12.
Spontaneous combustion characteristics are important issues for the safe operation of the wet-modified activated carbon drying process. The spontaneous combustion characteristics of activated carbon modified via liquid phase impregnation were fully investigated in this study. The modified activated carbon was prepared using columnar activated carbon and 4-amino-1,2-butanediol solution. Physical properties and surface functional group analyses were performed for activated carbon before and after modification. The ignition temperature of activated carbon before and after modification was then characterized using the methods of GB/T20450-2006, thermogravimetry-derivative thermogravimetry (TG-DTG), and TG-mass spectrometry (TG-MS). At the same time, the activation energy of activated carbon before and after modification was calculated by using thermodynamic analysis. Furthermore, a new self-designed test platform was introduced to investigate the spontaneous combustion characteristics of wet-modified activated carbon under the drying temperatures of 150, 175, 180, and 210 °C. The results show that the specific surface area of Brunauer, Emmett, and Teller (BET) is decreased by 368 m·g, the total volume of pore size is decreased by 0.17 cm·g, and the content of oxygen-containing functional groups is decreased by 0.071 mmol/g compared with row activated carbon. The ignition temperatures of the sample before modification characterized by the three methods are 483, 596, and 599 °C, respectively. The ignition temperatures of the sample after modification are 489, 607, and 611 °C, respectively. The activation energy of the modified activated carbon is increased by 35 kJ/mol compared to the original activated carbon. It is concluded that the temperature that triggers the modified activated carbon combustion during the drying process is between 175 and 180 °C, and the heat is mainly gathered at the longitudinal center of the combustion chamber through the investigation of spontaneous combustion experiments. The results in this study can contribute to safe production to prevent combustion in the process of modifying activated carbon during the drying process.
自燃特性是湿法改性活性炭干燥过程安全运行的重要问题。本研究对液相浸渍改性活性炭的自燃特性进行了全面研究。采用柱状活性炭和4-氨基-1,2-丁二醇溶液制备改性活性炭。对改性前后的活性炭进行了物理性质和表面官能团分析。然后采用GB/T20450-2006方法、热重-微商热重（TG-DTG）和TG-质谱（TG-MS）对改性前后活性炭的着火温度进行了表征。同时，通过热力学分析计算了改性前后活性炭的活化能。此外，引入了一个新的自行设计的试验平台，研究了在150、175、180和210℃干燥温度下湿改性活性炭的自燃特性。结果表明，与原活性炭相比，Brunauer-Emmett-Teller（BET）比表面积降低了368 m²/g，孔径总体积降低了0.17 cm³/g，含氧官能团含量降低了0.071 mmol/g。用三种方法表征的未改性样品的着火温度分别为483、596和599℃。改性后样品的着火温度分别为489、607和611℃。改性活性炭的活化能比原活性炭增加了35 kJ/mol。通过自燃实验研究得出，干燥过程中引发改性活性炭燃烧的温度在175至180℃之间，热量主要聚集在燃烧室的纵向中心。本研究结果有助于安全生产，防止干燥过程中改性活性炭过程中的燃烧。
