Liu Jinchang, Li Yaping, An Xiaoya, Shen Chenyang, Xie Qiang, Liang Dingcheng
School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China.
School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China.
Environ Res. 2022 Dec;215(Pt 1):114197. doi: 10.1016/j.envres.2022.114197. Epub 2022 Sep 1.
Wasted coal liquefaction residual was used to synthesize activated carbon fibers (ACFs) for CO capture, and the properties of the developed ACFs were optimized by adjusting the activation conditions, including the reaction temperature and soaking time. The yield, element distribution, pore structure, composition, functional group, morphology, and adsorption capacity of the as-synthesized ACFs were characterized by various apparatuses. In addition, static and dynamic adsorption experiments were conducted to investigate the adsorption capacity of CO in flue gas. The results revealed that the synthesized ACFs are mainly composed of carbon, accounting for more than 90% of the total elements. The specific surface area, pore volume, and pore width distribution of the prepared ACFs were optimized by changing the activation conditions, and ACFs with a specific surface area higher than 1400 m/g were successfully developed by activation at 950 for 3 h. The amount of micropores occupied more than 90% of the total pore volume. The pore width distribution dominated by micropores is beneficial for CO2 adsorption since the diameter of CO is 0.33 nm. From FTIR and XPS analysis, it is found that the main structure of ACFs is a carbon skeleton composed of polycyclic aromatic hydrocarbons with a small number of oxygen-containing functional groups. The adsorption isotherm of ACFs for CO conforms to the Langmuir model, indicating that the adsorption process of CO by ACFs can be attributed to monolayer adsorption. Both the specific surface area and oxygen-containing functional groups have crucial effects on the adsorption capacity of CO. The dynamic adsorption experiment determined that ACFs-920-3 had the highest adsorption capacity for CO in flue gas, and adsorption equilibrium was achieved after 7 min of adsorption. The adsorption process of CO in flue gas by the as-synthesized ACFs fits well with the pseudosecond kinetic model. The CO adsorption capacity of the obtained ACFs remained unchanged after 10 cycles of adsorption. A high-value-added route for synthesizing ACFs for CO capture using CLR as a raw material was developed.
废煤液化残渣被用于合成用于捕获二氧化碳的活性炭纤维（ACF），并通过调整活化条件（包括反应温度和浸泡时间）来优化所制备ACF的性能。采用多种仪器对合成的ACF的产率、元素分布、孔结构、组成、官能团、形态和吸附容量进行了表征。此外，进行了静态和动态吸附实验以研究ACF对烟气中二氧化碳的吸附容量。结果表明，合成的ACF主要由碳组成，占总元素的90%以上。通过改变活化条件优化了所制备ACF的比表面积、孔体积和孔宽分布，在950℃活化3小时成功制备出比表面积高于1400 m²/g的ACF。微孔数量占总孔体积的90%以上。以微孔为主的孔宽分布有利于二氧化碳吸附，因为二氧化碳的直径为0.33纳米。通过傅里叶变换红外光谱（FTIR）和X射线光电子能谱（XPS）分析发现，ACF的主要结构是由含有少量含氧官能团的多环芳烃组成的碳骨架。ACF对二氧化碳的吸附等温线符合朗缪尔模型，表明ACF对二氧化碳的吸附过程可归因于单层吸附。比表面积和含氧官能团对二氧化碳的吸附容量都有至关重要的影响。动态吸附实验确定ACF-920-3对烟气中二氧化碳的吸附容量最高，吸附7分钟后达到吸附平衡。合成的ACF对烟气中二氧化碳的吸附过程与准二级动力学模型拟合良好。所制备的ACF经过10次吸附循环后，二氧化碳吸附容量保持不变。开发了一种以CLR为原料合成用于捕获二氧化碳的ACF的高附加值路线。
