减压条件下氯化锌活化油茶果壳活性炭的制备工艺

Preparation of Activated Carbons from Oiltea Shell Promoted by Zinc Chloride in Vacuum

以油茶果壳为原料,以氯化锌为活化剂,在减压条件下热裂解制备活性炭。探讨氯化锌溶液的质量分数、体系压力、活化温度、活化时间对活性炭吸附性能的影响;通过低温氮气吸-脱附表征了样品的比表面积及孔结构,采用红外光谱仪分析了样品的表面官能团。得到制备该活性炭的最佳工艺条件为:氯化锌溶液的质量分数为60%、料液比1∶3(即每毫克固体物料加入3 m L液体物料,下同)、体系压力为0.05 MPa、活化温度为450℃、活化时间为1 h,在该条件下得到的活性炭碘吸附值为1 120 mg/g,亚甲基蓝吸附值为373.16 mg/g,比表面积为2 023.15 m2/g,总孔体积为2.34 cm3/g,平均孔径为4.63 nm。减压条件下制备的活性炭具有优良的吸附性能。

Activated carbons were prepared by thermal cracking of oiltea shell under vacuum condition using zinc chloride as activating reagent. The factors affecting the adsorption properties of activated carbons were studied, including the mass fraction of zinc chloride solution, system pressure, activation time and activation temperatures. The surface area and porosity characteristics were determined through the analysis of N2 adsorption-desorption isotherms. The functional groups on the surface were analyzed by FTIR spectroscopy. The results show that the optimized conditions for the preparation of activated carbon are as follows ： mass fraction of zinc chloride solution of 60% , material-to-liquid ratio of 1 ： 3 （g：mL）, system pressure of 0. 05 MPa, activation temperature of 450 ℃ and activation time of 1 h. The iodine absorption value and methylene blue absorption value of the prepared activated carbon are 1 120 mg/g and 373.16 mg/g, respectively. The surface area is 2 023.15 m2/g and total porous volume is 2.34 cm3/g with an average porous diameter of 4. 63 nm. The activated carbons prepared under vacuum condition have good absorption performance.