葵花秆基活性炭的吸附性能研究

西安科技大学 化学与化工学院,陕西 西安 710054

葵花秆半焦; 活性炭; 亚甲基蓝; 吸附

Adsorption properties of sunflower stalk based activated carbon
LIU Yuan,HE Xin-fu,ZHAO Dan-dan,SONG Cheng-jian,REN Xiu-bin,ZHANG Ya-gang,ZHOU An-ning

(College of Chemistry and Chemical Engineering,Xi'an University of Science and Technology,Xi'an 710054,China)

sunflower stalk char; activated carbon; methylene blue; adsorption

DOI: 10.13800/j.cnki.xakjdxxb.2016.0216

备注

为进一步优化生物质基活性炭性能及开拓其应用领域,以葵花秆为原料,在N2气氛下通过管式炉热解制得生物质半焦,以该生物质半焦为前驱体,利用水蒸气活化制备了葵花秆基活性炭。采用扫描电子显微镜(Scanning electron microscope,SEM)、低温氮气吸附(Low temperature nitrogen adsorption,N2 adsorption)和亚甲基蓝(MB)吸附等方法对活性炭的结构和吸附性能进行了研究。结果 表明,葵花秆经过550 ℃热解可以得到19.25%的焦油、19.84%的热解气以及23.53%生物质半焦,半焦在800 ℃下,经过水蒸气活化可制得比表面积为576.05 cm2/g的葵花秆基活性炭,其对亚甲基蓝的吸附等温线符合Freundlich模型,吸附为颗粒内扩散过程控制,吸附动力学符合二级吸附动力学模型。葵花秆半焦经水蒸气活化可制备出吸附性能良好的活性炭。

In order to optimize the performance of biomass-based activated carbon and develop its applications,sunflower stalk as raw material could be converted to biomass char by pyrolysis through the tube furnace reactor under nitrogen atmosphere.Biomass char was used as a precursor to prepare activated carbon using steam as a physical activation agent.The activated carbon was characterized with Scanning electron microscope(SEM),Low temperature nitrogen adsorption(N2 adsorption)and methylene blue(MB)adsorption.The results show that sunflower stalk pyrolysis in 550 ℃,the yield of tar,gas and biomass chars is 19.25%,19.84% and 23.53%,respectively.Biomass activated carbon can be prepared from sunflower stalk char with steam activation at 800 ℃,and the surface area of biomass activated carbon is 576.05 cm2/g.The MB adsorption equilibrium on activated carbon can be described in terms of Freundlich isotherm,and the kinetics of methylene blue on activated carbon was fitted second order kinetic model.Using steam as activating agent,activated carbon with good adsorption properties could be prepared from sunflower stalk semi-coke.