摘要
以气化稻壳炭(GRHC)为原料,KOH为活化剂制备活性炭,研究了不同活化温度和碱炭比对活性炭得率、比表面积、孔径分布以及碘值的影响。利用全自动气体吸附分析仪、X射线衍射仪、傅里叶变换红外光谱仪、扫描电镜等仪器对活性炭的理化性质进行表征,并通过吸附等温线、吸附动力学探讨其对甲基橙的吸附机制。结果表明:活化时间为1 h时,随着活化温度和碱炭比的增加,活性炭得率逐渐下降,比表面积和碘吸附值呈先增加后减少的趋势;气化稻壳炭制备活性炭的最佳工艺为碱炭比2∶1、活化温度800℃、活化时间1 h,此条件下制备的活性炭得率41.73%、比表面积1829.09 m^2/g,总孔容1.007 cm^3/g、碘吸附值1984.85 mg/g、甲基橙饱和吸附量为217.87 mg/g。气化稻壳活性炭对甲基橙的吸附过程与Langmuir和Freundlich模型相关性都良好(R2>0.99),吸附动力学更加符合准二级动力学模型。
Potassium hydroxide(KOH)was used as activating agent to prepare activated carbon with gasified rice husk char(GRHC)as raw material.The effects of activation temperature and mass ratio of KOH to char on the specific surface area,pore diameter distribution and iodine value of activated carbon were investigated.The physicochemical properties of activated carbon were characterized by automatic gas adsorption analyzer,X-ray diffraction,Fourier transform infrared spectrometer,and scanning electron microscope,et al.The adsorption mechanism of methyl orange was studied by adsorption isotherm and adsorption kinetics.The results showed that when the activation time was 1 h,the yield of activated carbon decreased gradually with the increase of activation temperature and alkali-carbon ratio,and the specific surface area and iodine adsorption value increased first and then decreased.The optimal conditions for preparation of activated carbon were mass ratio of KOH to char 2∶1 and activation temperature of 800℃.Under these conditions,the specific surface area,total pore volume,iodine value and saturated adsorption value of methyl orange reached their maximum values of 1829.09 m^2/g,1.007 cm^3/g,1984.85 mg/g and 217.87 mg/g,respectively and the yield of activated carbon was 41.73%.The adsorption process of methyl orange by activated carbon was highly correlated with Langmuir and Freundlich models(R2>0.99),and the adsorption kinetics was more consistent with the pseudo-second-order kinetic model.
作者
吴有龙
徐嘉龙
马中青
蔡伟
刘晓欢
钱俊
WU Youlong;XU Jialong;MA Zhongqing;CAI Wei;LIU Xiaohuan;QIAN Jun(School of Engineering,Zhejiang Provincial Collaborative Innovation Center for Bamboo Resources and High-Efficiency Utilization,Zhejiang A&F University,Hangzhou 311300,China)
出处
《生物质化学工程》
CAS
2021年第1期31-38,共8页
Biomass Chemical Engineering
基金
浙江省自然科学基金资助项目(LQ19E060009)
中国科协“青年人才托举工程”项目(2018QNRC001)
浙江省大学生科技创新活动计划暨新苗人才计划(2019R412042)。
关键词
气化稻壳炭
氢氧化钾法
比表面积
活性炭
甲基橙
吸附
gasified rice husk char
KOH method
specific surface area
activated carbon
methyl orange
adsorption
