Abstract In this study, different micro/mesoporous silica gel (MMSG) materials were prepared by mixed sol-gel process of polyethylene imine (PEI) and silicate. The developed materials were used to explore the optimal conditions for hexamethyldisiloxane (L2) removal in dynamic adsorption experiments. MMSG prepared using the conditions of pH = 3 and mPEI = 1.0 g was observed to be the optimum adsorbent for L2, which demonstrated an adsorption capacity of 367.1 ± 9.5 mg·g−1 using 83.82 mg·L−1 of L2 with dry N2 as the carrier gas. In addition, the influence of adsorption temperature and L2 inlet concentration were also investigated using dynamic adsorption experiments. Characterization of the MMSG material was carried out using several physical and chemical techniques, such as XRD, SEM and N2-BET. The results concluded that the L2 adsorption capacities were strongly related to the textural development of MMSG, especially the pore volume and surface area of micro/mesopores. Finally, MMSG regeneration could be easily achieved via heating at 100 °C, and its adsorption capacity for L2 was observed to be stable in the subsequent continuous dynamic adsorption experiments. These results indicated that the developed MMSG material represents a promising siloxane removal adsorbent for biogas up-gradation.

中文翻译：

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聚乙烯亚胺调控微孔/介孔硅胶提高硅氧烷去除率

摘要 本研究采用聚乙烯亚胺（PEI）和硅酸盐的混合溶胶-凝胶工艺制备了不同的微/介孔硅胶（MMSG）材料。开发的材料用于探索在动态吸附实验中去除六甲基二硅氧烷 (L2) 的最佳条件。观察到使用 pH = 3 和 mPEI = 1.0 g 的条件制备的 MMSG 是 L2 的最佳吸附剂，使用 83.82 mg·L-1 的 L2 和干燥的 N2 证明其吸附容量为 367.1 ± 9.5 mg·g-1作为载气。此外，还使用动态吸附实验研究了吸附温度和 L2 入口浓度的影响。MMSG 材料的表征使用几种物理和化学技术进行，例如 XRD、SEM 和 N2-BET。结果表明，L2 吸附能力与 MMSG 的结构发展密切相关，尤其是微孔/中孔的孔体积和表面积。最后，通过在 100°C 加热可以轻松实现 MMSG 再生，并且在随后的连续动态吸附实验中观察到其对 L2 的吸附容量是稳定的。这些结果表明，开发的 MMSG 材料代表了一种有前途的用于沼气升级的硅氧烷去除吸附剂。