水蒸气活化法制备椰壳活性炭的研究  

PREPARATION OF ACTIVATED CARBON FROM COCONUT SHELL WITH STEAM ACTIVATION

作　　者：王宁[1] 苏伟[1] 周理[1] 周亚平[2] 

机构地区：[1]天津大学化工学院化工研究所 [2]天津大学理学院化学系,天津300072

出　　处：《炭素》2006年第2期44-48,共5页Carbon

基　　金：国家自然科学基金重点项目(20336020)

摘　　要：以炭化椰壳为原料,以水蒸气为活化剂制备活性炭,系统分析了水蒸气流量、活化时间、蒸气用量等因素对活性炭性能的影响。结果表明:在活性炭未被过度活化的条件下,活性炭烧失率的大小可以直接反映出其比表面积。活化时间和水蒸气用量是影响活性炭制备成本的两个重要因素,提高水蒸气流量可以缩短活化时间,但会使水蒸气用量增大。孔径分布计算结果显示,活性炭的孔径基本都集中在2nm以下,烧失率越高,活性炭的孔径分布就越宽。Activated carbons were prepared from coconut shell using steam activation. Adsorption isotherms of nitrogen at—196℃ had been measured. Surface area of the carbons was determined from Dubinin—Radushkevich （D—R） equation rather than the BET equation for all the adsorption isotherms had the properties of type—Ⅰ. Using the simplified local density （SLD） model as the local adsorption isotherm in a pore,and summing up the amount adsorbed over a definite range of pore sizes,the pore size distribution of a sample was determined on fitting the model to the experimental adsorption isotherm. The results showed that carbons with surface area greater than Ⅰ 500 m^2 · g^（-1） and pore size lower than 2nm could be produced at 900℃ for 1～4h. The carbon with higher degree of burn—off had a wider distribution. Activation time could be reduced by increasing steam flow,but more steam had to be consumed. In most cases,bothe the adsorption ability and surface area were increased as the degree of burn—off was improved.

关 键 词：活性炭 椰壳 水蒸气活化 孔径分布 

分 类 号：TQ424.1[化学工程]