Ariyanto Teguh, Masruroh Kuni, Pambayun Gita Yunita Sri, Mukti Nur Indah Fajar, Cahyono Rochim Bakti, Prasetya Agus, Prasetyo Imam
Department of Chemical Engineering, Faculty of Engineering, Universitas Gadjah Mada, 55281 Yogyakarta, Indonesia.
Carbon Material Research Group, Department of Chemical Engineering, Universitas Gadjah Mada, 55281 Yogyakarta, Indonesia.
ACS Omega. 2021 Jul 15;6(29):19194-19201. doi: 10.1021/acsomega.1c02545. eCollection 2021 Jul 27.
The separation of CO/CH using porous carbon can be increased by the presence of a functional group of nitrogen on the carbon surface. This study explores the potential of porous carbon derived from the palm kernel shell (C-PKS) impregnated with a deep eutectic solvent (DES), which is one of the chemicals containing a nitrogen element. The DES was composed of a quaternary ammonium salt of choline chloride (ChCl) and a hydrogen bond donor of alcohol. Three alcohols of 1-butanol (-ol), ethylene glycol (-diol), and glycerol (-triol) were employed to study the effects of a number of hydroxyl groups in the separation performance. The research steps included (i) the preparation of DES-impregnated porous carbon synthesized from the palm kernel shell (DES/C-PKS), (ii) characterization of the material, and (ii) a separation test of CO/CH with a breakthrough system. Materials were characterized using scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDX), N-sorption analysis, and Fourier transform infrared (FTIR) spectroscopy. SEM images showed a significant morphological difference of pristine carbon and DES/C-PKS. There was a significant decrease in the range of 67-73% of a specific surface area with respect to pristine carbon, having initially 800 m/g. However, the N element on the carbon surface increased after impregnation treatment, which was shown from the intensity of the FTIR graphs and EDX analysis. Adsorption isotherm revealed that DES/C-PKS could enhance up to 1.6 times the adsorption capacity of CO at 1 atm and 30 °C while increasing the selectivity of CO/CH up to 125%. The breakthrough experiment showed that all DES/C-PKS materials displayed a better performance for the separation of CO/CH, indicated by a longer breakthrough time and enhancement of CO uptake. The best separation performance was achieved by DES/C-PKS using glycerol as a hydrogen bond donor with 15.4 mg/g of CO uptake or equivalent to 95% enhancement of the uptake capacity compared to pristine porous carbon. Also, the cycling test revealed that DES/C-PKS can be used repetitively, which further highlights the efficiency of the material for the separation of CO/CH.
通过在碳表面存在氮官能团，可以提高使用多孔碳分离CO/CH的效果。本研究探讨了浸渍有深共熔溶剂（DES）的棕榈仁壳衍生多孔碳（C-PKS）的潜力，DES是含氮元素的化学品之一。DES由氯化胆碱季铵盐（ChCl）和醇类氢键供体组成。使用1-丁醇（-ol）、乙二醇（-二醇）和甘油（-三醇）三种醇来研究羟基数量对分离性能的影响。研究步骤包括：（i）制备由棕榈仁壳合成的浸渍DES的多孔碳（DES/C-PKS），（ii）对材料进行表征，以及（iii）使用突破系统对CO/CH进行分离测试。使用扫描电子显微镜（SEM）结合能量色散X射线光谱（EDX）、N吸附分析和傅里叶变换红外（FTIR）光谱对材料进行表征。SEM图像显示原始碳和DES/C-PKS存在显著的形态差异。相对于初始比表面积为800 m²/g的原始碳，比表面积在67 - 73%范围内显著降低。然而，浸渍处理后碳表面的N元素增加，这从FTIR图谱的强度和EDX分析中可以看出。吸附等温线表明，DES/C-PKS在1 atm和30°C下可将CO的吸附容量提高至1.6倍，同时将CO/CH的选择性提高至125%。突破实验表明，所有DES/C-PKS材料在CO/CH分离方面表现出更好的性能，表现为更长的突破时间和CO吸收量的增加。使用甘油作为氢键供体的DES/C-PKS实现了最佳分离性能，CO吸收量为15.4 mg/g，与原始多孔碳相比，吸收容量提高了95%。此外，循环测试表明DES/C-PKS可以重复使用，这进一步突出了该材料在CO/CH分离方面的效率。
