微波辐射紫茎泽兰制备优质活性炭的研究

以紫茎泽兰为原料,碳酸钾为活化剂,采用超声波浸渍,微波辐射法制备活性炭.研究了浸渍方式与时间、微波功率、微波辐射时间、剂料比对活性炭吸附性能和得率的影响.得到了本实验条件下的优化工艺条件:超声波浸渍20min、120℃脱水2h,微波功率700W、微波辐射时间12min、剂料比1.25∶1.优化工艺条件下制备的活性炭碘吸附值为1470.27mg/g,亚甲基蓝吸附值为300mL/g,得率为16.35%.浸渍时间极大的缩短,微波辐射时间只有传统法活化时间的1/15左右,活性炭的吸附指标超过了国标GB/T 13803.1-1999和GB/T 13803.2-1999一级品的标准,其中碘吸附值是国家一级标准的1.47倍,亚甲基蓝吸附值是国家一级标准的2.73倍.同时,测定了该活性炭氮吸附,其BET比表面积为1540.97m2/g,总孔容为0.7393mL/g,并通过DFT表征了活性炭的孔径分布,结果表明该活性炭为微孔型活性炭.

STUDY ON THE PREPARATION OF ACTIVATED CARBON FROM EUPATORIUM ADENOPHORUM SPRENG BY MICROWAVE RADIATION

A series of activated carbons were prepared with eupatorium adenophorum Spreng as raw materials and potassium carbonate as activating agent, using Ultrasound impregnating and microwave radiation procedure. The effect of process variables such as the method and time of impregnating, the ratio of K2CO3 to eupatorium adenophorum Spreng, microwave power and microwave radiation time on the yield and adsorption properties of activated carbon were systematically studied. The optimum conditions for preparing activated carbon by ultrasound-microwave were obtained: drying for 2h after ultrasound impregnating 20min, microwave power was 700W, microwave radiation time was 12min and the ratio of K2CO3 to eupatorium adenophorum Spreng was1.25:1. The yield of the activated carbon was 16.35% when the methylene blue adsorption reached 300ml/g and the iodine number was 1470.27mg/g.The impregnating time is shorten greatly, the activating time is about 1/15 of traditional method. The adsorption properties of the obtained activated carbon exceed the first-graded of GB/T 13803.1-1999 and GB/T 13803.2-1999. The iodine number and methylene blue adsorption is 1.47 and 2.73 times of that the first grade product specified in the National Standard. Furthermore, the activated carbon in optimum technology was tested by nitrogen adsorption at 77K. The surface area of the carbons was estimated by BET, pore volume was estimated by the adsorption volume when p/p0 was 0.99 and the porous structures were investigated by Density Function Theory. The BET surface area and total pore volume are 1540.97m2/g and 0.7393mL/g, respectively. The results show that the activated carbon is predominantly microporous.