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生物质化学工程 ›› 2022, Vol. 56 ›› Issue (5): 23-29.doi: 10.3969/j.issn.1673-5854.2022.05.004

• 研究报告 • 上一篇    下一篇

脱气预处理条件对木质活性炭比表面积和孔容积分析结果影响初探

马名哲1, 孙康1,*(), 孙昊1, 张燕萍1, 林冠烽2, 魏安国3   

  1. 1. 中国林业科学研究院 林产化学工业研究所; 江苏省生物质能源与材料重点实验室; 国家林业和草原局林产化学工程重点实验室 林木生物质低碳高效利用国家工程研究中心; 江苏省林业资源高效加工利用协同创新中心, 江苏 南京 210042
    2. 福建农林大学 材料工程学院, 福建 福州 350003
    3. 福建芝星炭业有限公司, 福建 南平 353100
  • 收稿日期:2021-06-12 出版日期:2022-09-30 发布日期:2022-09-27
  • 通讯作者: 孙康 E-mail:sunkang0226@163.com
  • 作者简介:孙康, 研究员, 博士, 主要从事生物质炭基材料的基础与应用研究; E-mail: sunkang0226@163.com
    马名哲(1997—), 男, 黑龙江黑河人, 研究实习员, 本科, 主要从事炭质材料制备及吸附研究工作
  • 基金资助:
    中国林科院中央级公益性科研院所基本科研业务费专项资助(CAFYBB2018GD002-04)

A Preliminary Study of the Degassing Pretreatment Effect on the Specific Surface Area and Pore Volume of Woody Activated Carbon

Mingzhe MA1, Kang SUN1,*(), Hao SUN1, Yanping ZHANG1, Guanfeng LIN2, An'guo WEI3   

  1. 1. Institute of Chemical Industry of Forest Products, CAF; Key Lab. of Biomass Energy and Material, Jiangsu Province; Key Lab. of Chemical Engineering of Forest Products, National Forestry and Grassland Administration; National Engineering Research Center of Low-Carbon Processing and Utilization of Forest Biomass; Jiangsu Co-Innoration Center of Efficient Processing and Utilization of Forest Resource, Nanjing 210042, China
    2. School of Materials Engineering, Fuijan Agriculture and Forestry University, Fuzhou 350003, China
    3. Fujian Zhixing Carbon Iudustry Co., Ltd., Nanping 353100, China
  • Received:2021-06-12 Online:2022-09-30 Published:2022-09-27
  • Contact: Kang SUN E-mail:sunkang0226@163.com

摘要:

在测定木质活性炭比表面积和孔容积前, 先对活性炭进行脱气预处理, 研究预处理条件(脱气温度和脱气时间)对活性炭的比表面积和孔容积的影响, 并将所测结果与仪器推荐条件下所测结果进行对比分析。研究结果表明: 脱气温度和脱气时间对于物理法木质活性炭比表面积和孔容积分析结果影响较小, 这是因为物理法活性炭制备温度高, 官能团少, 结构以微孔为主, 吸附类型以物理吸附为主, 吸脱附速度较快。物理法活性炭预处理条件以脱气温度150 ℃脱气3 h为宜, 相较于ASAP 2460使用说明所推荐的350 ℃和24 h的预处理条件, 明显缩短预处理时间, 降低电耗, 提高了检测效率。脱气温度和脱气时间对化学法木质活性炭比表面积和微孔分析结果影响较大, 适宜的预处理条件为300 ℃脱附12 h。主要是因为磷酸法活性炭制备温度较低, 杂原子较多, 表面化学基团丰富, 发生物理吸附的同时易发生化学吸附, 需要较高的温度和较长的时间才能脱气完全, 当脱气温度过高时, 孔道内的吸附质发生炭化形成炭质微粒堵塞孔道, 同时部分物理吸附在更高的活化能下转化为化学吸附, 使分析结果有所下降。

关键词: 活性炭, 比表面积, 孔容积

Abstract:

Before determining the specific surface area and pore volume of woody activated carbon, the activated carbon was pre-treated with degassing, and the effect of pre-treatment conditions(desorption temperature and desorption time) on the specific surface area and pore volume of activated carbon was investigated. The obtained results were compared with those measured under the recommended conditions of the instrument. The results showed that the desorption temperature and time had little influence on the specific surface area and pore volume of physical activated carbon. It was owing to the preparation temperature of physical activated carbon was high few functional groups, the structure was mainly microporous, the adsorption type was mainly physical adsorption, and the adsorption and desorption speeds were fast. The optimum pretreatment condition of physical activated carbon was desorbed at a temperature of 150 ℃ for 3 hours. Compared with the pretreatment conditions of 350 ℃ and 24 hours recommended in the instruction manual of ASAP 2460, pretreatment time was significantly shortened, the power consumption was reduced, and the detection efficiency was improved. The degassing temperature and time had a great influence on the specific surface area and micro-pore of chemical wood activated carbon, and the suitable pretreatment condition was 300 ℃ for 12 h. The main reason was that the preparation temperature of activated carbon by phosphoric acid method was relatively low, and there were many heteroatoms and the surface chemical groups. Physical and chemical adsorption were easy to occur simultaneously, which required higher temperature and longer time for degassing. When the degassing temperature was too high, the adsorbate in the pores would be carbonized to form carbonaceous particles that blocked the pores. At the same time, part of the physical adsorption would be converted into chemical adsorption at a higher activation energy, which would reduce the analysis results.

Key words: activated carbon, specific surface area, pore volume

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