改性活性碳纤维对CO2的吸附性能

为了进一步提高活性碳纤维的CO₂吸附量和抗水性能，采用浸渍法将活性碳纤维进行改性处理，得到一系列改性样品，并对其进行了SEM和FTIR表征。研究了活性碳纤维种类、浸渍试剂（NaOH溶液、ZnCl₂溶液及离子液体）等对吸附剂孔结构、CO₂吸附量、循环使用性和抗水性能的影响，并探讨了CO₂在改性活性碳纤维内的动力学吸附扩散行为。研究结果表明：改性活性碳纤维的CO₂吸附性能和抗水性能均显著改善，其中CO₂最高吸附量达24.4%（0.1MPa和25℃），吸湿率减小到1.33%，且具有良好的吸附/脱附循环使用性。均相扩散模型（HSDM）描述了实时吸附数据，此模型能够较好地反映CO₂在样品内的扩散行为，改性活性碳纤维仍能保持良好的扩散速率，扩散系数D_s值数量级为10^-5m²/s，与空白活性碳纤维相当。

CO2 adsorption performance of modified activated carbon fibers

In order to increase the CO₂ adsorption capacity and to improve the water resistance of activated carbon fibers, a series of modified activated carbon fibers were prepared by impregnation method, and characterized by using scanning electron microscopy (SEM) and infrared spectroscopy (FTIR). The effects of the activated carbon fibers types and the immersion reagents (NaOH solution, ZnCl₂ solution and ionic liquid) on the pore structure, CO₂ adsorption capacity, cycling performance and water resistance of the adsorbents were studied. The adsorption kinetics and diffusion behaviors of CO₂ in the modified activated carbon fibers were also discussed. The results show that the CO₂ adsorption and water resistance of the modified activated carbon fibers are significantly improved, and the maximum adsorption capacity of CO₂ is 24.4% (0.1MPa and 25℃), and the moisture absorption rate was reduced to 1.33%. The adsorbents also performed well during the adsorption/desorption cycles. The homogeneous diffusion model (HSDM) was used to describe the real-time adsorption data, and reflected the diffusion behavior of CO₂ in the samples quite well. The modified activated carbon fiber can still maintain a high diffusion rate with the diffusion coefficients D_s at a level of 10^-5 m²/s, equivalent to that of the blank activated carbon fibers.