摘要
选择了水蒸气活化椰壳活性炭(AC-11、AC-12、AC-13),磷酸活化粉末状活性炭(AC-21、AC-22),以及KOH活化石油焦高比表面积活性炭(AC-31、AC-32)7种以常见方法制备的,比表面积在800~3500 m^(2)/g范围的活性炭,研究了2种I_(2)/KI质量比对活性炭碘吸附值测定结果的影响,并分析了活性炭比表面积和孔隙结构对碘吸附值的影响。研究结果显示:活性炭的比表面积越大、中孔越发达、中孔分布越宽,I_(2)/KI质量比对活性炭碘吸附值的影响就越大,m(I_(2))∶m(KI)为1∶1.5下测试样品AC-31的碘吸附值与其在m(I_(2))∶m(KI)为1∶2条件下的差值能达到140 mg/g;对于碘吸附值在800 mg/g左右的微孔型活性炭AC-13,2种比例测试得到的差值几乎可以忽略不计,也就是说旧版和新版的木质和煤质活性炭标准得到的活性炭碘吸附值差别很小。在活性炭碘吸附值测试条件下,吸附碘有效孔隙主要集中在0.8~1.5 nm之间。对于椰壳活性炭等微孔型活性炭,其比表面积值与碘吸附值差别不大,具有一定程度的等效性。I_(2)/KI质量比影响的实质是二者的比例变化决定了碘标准溶液中单质碘的起始浓度,从而影响了活性炭的碘吸附值。
This study investigated the effects of two different I_(2)/KI mass ratios on the iodine adsorption value of activated carbon prepared by seven common methods,with specific surface area ranging from 800 to 3500 m^(2)/g,including steam-activated coconut shell activated carbon(AC-11,AC-12,AC-13),phosphoric acid-activated powdered activated carbon(AC-21,AC-22),and KOH-activated petroleum coke high specific surface area activated carbon(AC-31,AC-32).The influence of specific surface area and pore structure of activated carbon on iodine adsorption value was analyzed.The results show that,activated carbons with a larger specific surface area,developed mesopore structure,and wide mesopore distribution,exhibited a more significant effect of the I_(2)/KI mass ratio on the iodine adsorption value.The difference between the iodine adsorption value of the test sample AC-31 under m(I_(2))∶m(KI)=1∶1.5 and that under m(I_(2))∶m(KI)=1∶2 could reach 140 mg/g.For microporous activated carbon AC-13 with iodine adsorption value around 800 mg/g,the difference between the two testing methods was almost negligible,which suggested that the difference between the activated carbon iodine adsorption value obtained by the old and new versions of wood and coal activated carbons iodine adsorption value testing standards was very small.Under the condition of activated carbon iodine adsorption value test,the pore sizes of activated carbon that effectively adsorb iodine molecules were mainly between the range of 0.8-1.5 nm.For microporous activated carbon such as coconut shell activated carbon,the value of the specific surface area was not much difference from the iodine adsorption value,with a certain degree of equivalence.The essence of the I_(2)/KI mass ratio influence was that the change of the ratio of the two determines the starling concentration of elementary iodine in the iodine stardard solution,which affected the iodine adsorption value of activated carbon.
作者
张莉
左宋林
王子庆
ZHANG Li;ZUO Songlin;WANG Ziqing(College of Chemical Engineering,Nanjing Forestry University,International Innovation Highland of Forest Products Chemistry and Materials,Jiangsu Key Laboratory of Agri-forest Biomass,Nanjing 210037,China;Zhejiang Ruineng Carbon Material Technology Co.,Ltd.,Deqing 313200,China)
出处
《林产化学与工业》
CAS
CSCD
北大核心
2023年第6期57-64,共8页
Chemistry and Industry of Forest Products
基金
国家重点研发计划资助项目(2019YFB1503804)。
关键词
活性炭
碘吸附值
碘和碘化钾质量比
比表面积
孔结构
activated carbon
iodine adsorption value
mass ratio of iodine and potassium iodide
specific surface area
pore structure
