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磷酸法木质素基活性炭活化过程研究 |
Study on H3PO4 activation process of lignin-based activated |
投稿时间:2020-02-17 修订日期:2020-04-20 |
DOI: |
中文关键词: 玉米芯木质素 活性炭 磷酸活化 活化机理 |
英文关键词: lignin activated carbon H3PO4 activation activation mechanism |
基金项目:国家自然科学基金项目(面上项目,重点项目,重大项目) |
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中文摘要: |
以玉米芯木质素为原料,采用磷酸活化法制备木质素基活性炭。结合FTIR、低温氮吸附、拉曼光谱等表征手段,探究了不同活化温度(300~600℃)及磷酸/木质素质量比(1:1~3:1)对活性炭孔隙结构的影响,并探究磷酸活化木质素的反应机理;对比研究了有无磷酸作用下木质素受热过程中气体产物的变化规律;实验结果表明,磷酸降低了木质素中官能团的断键温度,使得CO、CO2和CH4的生成温度降低;促进了高温下(>500℃)木质素半焦的缩聚,使高温下H2生成量增多;中孔和微孔在350℃以上开始发展,在500℃孔隙最为发达,温度的进一步升高使得孔体积减小;磷酸/木质素比增大可以提高中孔率。在活化温度500℃和磷酸/木质素比2~3条件下,制得活性炭比表面积达1046m2/g,收率55%。 |
英文摘要: |
Corncob lignin has been used to prepare Activated Carbons (ACs) by H3PO4 activation. Combine with the FTIR, low temperature N2 adsorption and Raman spectra, investigate the effects of different activation temperature (300~600℃) and mass ratio(1:1~3:1) on the pore structures of ACs and activation mechanism. Study on the evolution of gas products during the heating of lignin with or without H3PO4. The results indicate that the presence of H3PO4 lower the functional groups’ bond-cleavage temperature, thus lower the forming temperature of CO, CH4, CO2. Besides, H3PO4 also facilitates the aromatization of biochar at high temperature (>500℃), hence improves the H2 concentration. Mesoporous and microspores develop around 350℃, reach the maximum at 500℃. A higher temperature will leads to an over aromatization, results in the decreasing of pore volume. A larger mass ratio may induce a higher mesoporous volume. With the activation temperature at 500℃ and H3PO4/lignin mass ratio at 2~3, the BET surface of ACs reaches 1046m2/g, yield 55%. |
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