PEI/MEA 功能化二氧化硅对模拟沼气中二氧化碳的增强吸附。
Enhanced Adsorption of Carbon Dioxide from Simulated Biogas on PEI/MEA-Functionalized Silica.
机构信息
College of Resource and Environment, Northeast Agricultural University, Harbin 150030, China.
College of Arts and Sciences, Northeast Agricultural University, Harbin 150030, China.
出版信息
Int J Environ Res Public Health. 2020 Feb 24;17(4):1452. doi: 10.3390/ijerph17041452.
A series of efficient adsorbents were prepared by a wet-impregnation method for CO separation from simulated biogas. A type of commercially available silica, named as FNG-II silica (FS), was selected as supports. FS was modified with a mixture of polyethyleneimine (PEI) and ethanolamine (MEA) to improve the initial CO adsorption capacity and thermal stability of the adsorbents. The influence of different adsorbents on CO adsorption performance was investigated by breakthrough experiments. Scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), and N adsorption-desorption isotherm were used to characterize the silica before and after impregnating amine. Additionally, the thermal stability of adsorbents was measured by differential thermal analysis (TDA). Silica impregnated with mixtures of MEA and PEI showed increased CO adsorption performance and high thermal stability compared with those obtained from silica impregnated solely with MEA or PEI. With a simulated biogas flow rate of 100 mL/min at 0.2 MPa and 25 °C, FS-10%MEA-10%PEI exhibited a CO adsorption capacity of ca. 64.68 mg/g which increased by 81 % in comparison to FS-20%PEI. The thermal stability of FS-10%MEA-10%PEI was evidently higher than that of FS-20%MEA, and a further improvement of thermal stability was achieved with the increasing value of PEI/MEA weight ratio. It was showed that MEA was able to impose a synergistic effect on the dispersion of PEI in the support, reduce the CO diffusion resistance and thus increase CO adsorption performance. Additionally, if the total percentage of amine was the same, FS impregnated by different ratios of PEI to MEA did not exhibit an obvious difference in CO adsorption performance. FS-15%PEI-5%MEA could be regenerated under mild conditions without obvious loss of CO adsorption activity.
通过浸渍法制备了一系列高效吸附剂，用于从模拟沼气中分离 CO。选择一种市售的硅石，命名为 FNG-II 硅石（FS）作为载体。FS 用聚乙烯亚胺（PEI）和乙醇胺（MEA）的混合物进行改性，以提高吸附剂的初始 CO 吸附容量和热稳定性。通过穿透实验研究了不同吸附剂对 CO 吸附性能的影响。扫描电子显微镜（SEM）、傅里叶变换红外光谱（FTIR）和氮气吸附-脱附等温线用于表征浸渍胺前后的硅石。此外，通过差示热分析（TDA）测量了吸附剂的热稳定性。与仅浸渍 MEA 或 PEI 的硅石相比，浸渍 MEA 和 PEI 混合物的硅石表现出更高的 CO 吸附性能和更高的热稳定性。在模拟沼气流速为 100 mL/min、0.2 MPa 和 25°C 的条件下，FS-10%MEA-10%PEI 的 CO 吸附容量约为 64.68 mg/g，与 FS-20%PEI 相比增加了 81%。FS-10%MEA-10%PEI 的热稳定性明显高于 FS-20%MEA，并且随着 PEI/MEA 重量比的增加，热稳定性进一步提高。结果表明，MEA 能够在载体中促进 PEI 的分散，降低 CO 扩散阻力，从而提高 CO 吸附性能。此外，如果胺的总百分比相同，用不同比例的 PEI 和 MEA 浸渍的 FS 在 CO 吸附性能方面没有明显差异。FS-15%PEI-5%MEA 可以在温和条件下再生，而 CO 吸附活性没有明显损失。
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