| 蒲瀛州, 徐绍平, 王克超, 冯艳春, 王雯雯.磷酸法木质素基活性炭活化过程研究[J].,2020,60(4):349-357 |
| 磷酸法木质素基活性炭活化过程研究 |
| Study of phosphoric acid activation process of lignin-based activated carbons |
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| DOI：10.7511/dllgxb202004003 |
| 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: corncob lignin activated carbon phosphoric acid activation activation mechanism |
| 基金项目:国家自然科学基金资助项目(21376046). |
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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℃)及磷酸与木质素质量比(1~3)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;磷酸与木质素质量比增大可以提高中孔率.在活化温度500℃ 和磷酸与木质素质量比2~3条件下,制得活性炭比表面积达1046 m2/g,收率55%. |
| 英文摘要: |
| Corncob lignin is used to prepare lignin-based activated carbons (ACs) by phosphoric acid activation. The FTIR, low temperature N2 adsorption and Raman spectra are adopted to investigate the effects of activation temperature (300-600 ℃) and H3PO4 and lignin mass ratio (1-3) on the pore structures of ACs and activation mechanism. Comparative study is conducted on the evolution of gas products during the heating of lignin with or without H3PO4. The results indicate that the presence of H3PO4 lowers the functional groups′ bond-cleavage temperature, thus lowers the forming temperature of CO, CO2, CH4. Besides, H3PO4 also facilitates the aromatization of biochar at high temperature (>500 ℃), hence improves the H2 concentration. Mesopores and micropores develop above 350 ℃, and reach the maximum at 500 ℃. A higher temperature will lead to an over aromatization and result in the decreasing of pore volume. A larger H3PO4 and lignin mass ratio may induce a higher mesoporous volume. With the activation temperature of 500 ℃ and H3PO4 and lignin mass ratio of 2-3, the BET surface of ACs reaches 1 046 m2/g, and the yield is 55%. |
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