兰炭基活性炭的制备工艺优化及吸附性能研究

以榆林某公司的兰炭为原料,KOH粉末为活化剂制备活性炭。通过改变活化过程中时间、温度、炭碱比等因素,从而探究活性炭的碘吸附能力。通过响应曲面优化处理活性炭制备过程中活化因素,从而确定最佳工艺。采用比表面积测定,红外光谱分析,扫描SEM电镜等对活性炭结构及性能表征进行分析结果表明,上述活化条件都会影响活性炭吸附能力和孔隙结构。当活化过程中的温度达到750℃,时间为0.5 h,炭碱比为1:3的时候,KOH的活化效果最佳,所制样品的碘吸附值最大且为1 162.91 mg/g,其BET比表面积可达655.15m2/g,Langmuir比表面积为908.22 m2/g。通过红外分析可知活性炭与预处理兰炭原料红外光谱图走势极其相似,只是活性炭出现了较强的芳基烷基醚C-O伸缩振动峰。通过扫描显微电镜分析可知与原料兰炭相比,活性炭样品组织表面非常粗糙并且有大量的孔隙出现,样品结构非常疏松。

Preparation and Adsorption Properties of Semi-coke Based Activated Carbon

Taking semi-coke of a Yulin company as raw material, KOH powder as activator, acticvated carbon was prepared. The iodine adsorption capacities of different activated carbon samples prepared under different activation time, temperature, carbon-alkali ratio and other factors were investigated. The optimal process was determined by optimizing the activation factors during the preparation of the activated carbon by the response surface. The structure and properties of activated carbon were analyzed by specific surface area measurement, infrared spectroscopy, scanning SEM and so on. The results show that the activation conditions can affect the adsorption capacity and pore structure of activated carbon. When the activation temperature is 750℃, the time is 0.5 h and the ratio of carbon to alkali is 1: 3, the activation effect of KOH is the best, and the iodine adsorption value of the sample is 1162.91 mg/g, the BET specific surface area is up to 655.15 m2/g, Langmuir specific surface area is 908.22 m2/g. The infrared spectra show that the infrared spectrum of the activated carbon is very similar to one of the pretreated semi-coke raw material, but the activated carbon has a strong aryl alkyl ether C-O stretching vibration peak. The microstructure of the activated carbon sample is very rough and a large number of pores appear on the surface of the activated carbon sample, and the sample structure is very loose.