School of Chemical and Metallurgical Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, Wits, Johannesburg, 2050, South Africa.
Environ Sci Pollut Res Int. 2019 Nov;26(32):32746-32758. doi: 10.1007/s11356-019-05953-x. Epub 2019 Jul 29.
Industrial hydrodesulfurization method has not been efficient for removal of dibenzothiophene (DBT) from petroleum distillates. Therefore, in this current study, adsorptive desulfurization (investigated in batch mode) was carried out using functionalized carbon nanotubes (FCNTs) to reduce the amount of DBT in a model diesel. Different techniques, such as, scanning electron microscope (SEM) equipped with energy-dispersive X-ray (EDX), were used to check the morphological structure and the elemental compositions of the adsorbent; Fourier transmission infrared (FTIR) was used to check the chemical functionalities of the adsorbent; and nitrogen physisorption at 77 K was used to check the surface area, pore size, and pore volume of the adsorbent. The results show that the FCNTs outperformed the non-functionalized carbon nanotubes (CNTs) during the desulfurization by about 10%, indicating the functionalization did improve the desulfurization performance of the CNTs. The % removal of DBT by the FCNTs and CNTs was 70.48 and 60.88%, respectively. It can be concluded that the acid treatment of CNTs enhanced its surface affinity for DBT, thus contributing to the improved adsorption performance of the adsorbent. The isotherm results show that Freundlich isotherm model described well the mechanism of the adsorption process for both CNTs and FCNTs. In addition, pseudo second-order kinetics describes the behavior of the adsorbents during the adsorption process. The results obtained in this study therefore show that functionalized CNTs could be efficient and potential adsorbent for removal of DBT in petroleum distillate (e.g., diesel), to meet up with the stringent policies regarding emission of sulfur oxides.
工业加氢脱硫方法对于从石油馏分中去除二苯并噻吩（DBT）的效果并不理想。因此，在本研究中，通过使用功能化碳纳米管（FCNTs）进行吸附脱硫（在间歇模式下进行研究），以减少模型柴油中二苯并噻吩的含量。使用了不同的技术，例如配备能量色散 X 射线（EDX）的扫描电子显微镜（SEM），来检查吸附剂的形态结构和元素组成；傅里叶变换红外（FTIR）用于检查吸附剂的化学官能团；77 K 下的氮气物理吸附用于检查吸附剂的表面积、孔径和孔体积。结果表明，在脱硫过程中，FCNTs 的表现优于非功能化碳纳米管（CNTs），约提高了 10%，这表明功能化确实提高了 CNTs 的脱硫性能。FCNTs 和 CNTs 对 DBT 的去除率分别为 70.48%和 60.88%。可以得出结论，对 CNTs 进行酸处理增强了其对 DBT 的表面亲和力，从而提高了吸附剂的吸附性能。等温线结果表明，Freundlich 等温线模型很好地描述了 CNTs 和 FCNTs 吸附过程的机制。此外，拟二级动力学描述了吸附剂在吸附过程中的行为。因此，本研究的结果表明，功能化 CNTs 可能是一种有效的、有潜力的吸附剂，可用于去除石油馏分（如柴油）中的 DBT，以满足有关硫氧化物排放的严格政策。
