膨胀珍珠岩负载碳纳米管膜的表征及其对甲苯吸附性能初探

Characterization of expanded perlite supported carbon nanotube films and their toluene adsorption properties

为了解决传统颗粒型吸附剂压降过大,传质效率低等问题,采用化学气相沉积法(CVD),以樟脑为前驱体在膨胀珍珠岩表面成功合成了碳纳米管(CNT)膜,构成了具有梯度多孔结构的膨胀珍珠岩碳纳米管膜(CNTs/Perlite)复合材料。结果表明,当生长温度和时间分别为800℃和40 min,樟脑用量为2 g时,合成的CNT生长密度高、热稳定性强、表面缺陷结构少。同时系统研究了甲苯在不同CNT与CNTs/Perlite比例下构成的结构化床层上的吸附透过行为。结果表明,结构化固定床层(1.5 cm CNT+0.5 cm CNTs/Perlite)的无效床层厚度由1.028降低为0.984 cm,床层利用率从48.6%提高为50.8%,传质速率k¢从0.0416提高到0.0596 min^(-1)。作为一种梯度孔结构材料,膨胀珍珠岩碳纳米管膜能够显著降低床层阻力,提高传质速率,为工业应用提供了一种新思路。

In order to solve the problems of high pressure drop and low mass transfer efficiency of traditional granular adsorbents,carbon nanotube(CNT)films were synthesized on expanded perlite surface via chemical vapor deposition(CVD)using camphor as precursor to form expanded perlite carbon nanotubes membrane(CNTs/Perlite)composites with gradient porous structure.The results show that when the growth temperature and time are 800℃ and 40 min respectively,and the amount of camphor is 2 g,the synthesized CNT has high growth density,strong thermal stability and less surface defect structure.Meanwhile,adsorption and permeation behaviors of toluene on the structured bed with different CNT and CNTs/Perlite ratios was studied systematically.The results show that the length of unused bed Lub(1.5 cm CNT+0.5 cm CNTs/Perlite)is reduced from 1.028 to 0.984 cm,the bed utilization is increased from 48.6% to 50.8%,and the mass transfer rate k'is increased from 0.0416 to 0.0596 min^(-1).Expanded perlite carbon nanotube films as a gradient pore structure material can significantly reduce bed resistance and increase mass transfer rate,which provides a new idea for industrial application.