高比表面积铜藻基活性炭的制备及工艺优化

Preparation and optimization of high-performance activated carbons from Sargassum Horneri by chemical activation

以铜藻为原料,在对其进行元素含量、生化组成分析的基础上,分别采用ZnCl2活化法和H3PO4活化法制备活性炭,并以活性炭得率、碘吸附值、焦糖脱色率为指标,采用正交法考察了升温速率、活化温度、浸渍比(活化剂/铜藻质量比)等因素的影响,得到最佳工艺条件.同时,采用扫描电镜(SEM)、Brunauer-Emmet-Tller(BET)比表面积等方法分析活性炭特征.结果表明,铜藻原料粒度对制得的活性炭性能影响显著,106～180μm的颗粒较为适合.ZnCl2活化法制得的活性炭吸附性能明显优于H3PO4活化法;ZnCl2活化法的最佳工艺条件为:升温速率10℃.min-1、活化温度600℃、活化时间2h、浸渍比4,在保证活性炭得率超过30%的基础上,制备的活性炭比表面积为2314.58m2.g-1,碘吸附值为835.3mg.g-1,焦糖脱色率为110%,性能明显优于其他大型海藻原料所制备的活性炭,是陆地传统活性炭原料的有效补充.

Activated carbons were prepared from Sargassum Horneri by zinc chloride activation and phosphoric acid activation according to orthogonal method under nitrogen protection.Based on the analysis of elemental and biochemical compositions of Sargassum Horneri,the influence of several factors,including heating rate,activation temperature,activation time and impregnation ratio（the weight of activation agent to the weight of Sargassum Horneri） on the yield,iodine value,decolorization rate of caramel was investigated.Activated carbon prepared at the optimal condition was analyzed by Scanning Electron Microscopy（SEM）,Brunauer-Emmet-Tller（BET） surface area,and so on.The results indicated that zinc chloride is better than phosphoric acid in preparing Sargassum Horneri-based activated carbon.The size of particle obviously affects the iodine number of activated carbon,with 106~180 μm being the most optimal size.High performance activated carbons could be prepared by zinc chloride activation.Under the optimal condition of heating rate of 10 ℃ · min-1,activation temperature of 600 ℃,activation time of 2 h and impregnation ratio of 4,the yield could reach more than 30%,with the specific surface area of 2314.58 m2 · g-1,the iodine value of 835.3 mg · g-1,and the decolorization rate of caramel of 110%.Sargassum Horneri-based activated carbons perform better than those based on macro algae,which serve as good alternatives for traditional territorial activated carbon source.