Effect of thermal modification on desulfurization capacity of column activated carbon
SHE Xue-feng1, LIU Song-hao1, WANG Yan-jiang2, WANG Jian-fang2, WANG Jing-song1, XUE Qing-guo1
1. State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China; 2. Sintering Plant, Delong Steel, Xingtai 054000, Hebei, China
Abstract:Five kinds of modified activated carbons (AC-1 to AC-5) were obtained by thermal modification of columnar activated carbons at different temperatures under the protection of N2. The activated carbons (AC) before and after modification were placed in the condition containing SO2 and in the presence of water vapor and oxygen respectively for desulfurization experiment. The physical properties of activated carbon surface before and after modification were characterized by gas adsorption apparatus and scanning electron microscope. The experimental results show that when the modification temperature is 700-900 ℃, the desulfurization ability of the modified activated carbon increases with the increase of the modification temperature, when the modification temperature is 900 ℃, the desulfurization ability of the activated carbon is the strongest, when the modification temperature is 1 100 ℃, the desulfurization ability of the activated carbon decreases obviously. Gas adsorption apparatus of the proceeds of the BET the results of the analysis, and scanning electron microscopy the results show that activated carbon part was blocked in the process of heating channel is opened, increase its adsorption surface area, to improve the initial activated carbon desulfurization rate is good, but too high temperature will destroy the original structure of aperture, activated carbon in AC-4 and AC-5 samples of the desulfurization ability becomes poor. In addition, temperature-programmed desorption technology (TPD) was used to analyze the pH content of activated carbon samples from AC to AC-4. The results showed that there was a good proportional linear relationship between the ph content of strong alkali center on the surface of activated carbon and its desulfurization ability. By comparing the samples AC-2 and AC-3, it can be found that under the condition of little difference in the physical properties of activated carbon, the improvement of its desulfurization ability mainly benefits from the change of surface chemical properties, especially the enhancement of alkalinity. At the same time, through the Boehm titration and combined with Fourier transform infrared spectrometer (FTIR) of activated carbon samples AC and AC-3 the surface acidic functional groups of change were analyzed, and found that the thermal modified activated carbon surface carboxyl, lactone and decrease in the number of hydroxyl groups, shows that heat treatment can make the surface acidic functional groups of activated carbon decomposition, is helpful to promote its desulfurization ability.
佘雪峰, 刘松昊, 王延江, 王建芳, 王静松, 薛庆国. 热改性对柱状活性炭脱硫能力的影响[J]. 钢铁, 2022, 57(4): 130-137.
SHE Xue-feng, LIU Song-hao, WANG Yan-jiang, WANG Jian-fang, WANG Jing-song, XUE Qing-guo. Effect of thermal modification on desulfurization capacity of column activated carbon[J]. Iron and Steel, 2022, 57(4): 130-137.
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