疏水型核壳沸石13X@SiO2的制备及其捕集高湿烟道气中CO2的研究

Since water adsorption is much stronger than CO2 adsorption on zeolite 13X, the CO2 adsorption capacity of zeolite 13X decreased a lot in the presence of water vapor. In this work an attempt will be made to make zeolite 13X hydrophobic.The approach of synthesizing zeolite 13X@SiO2 core-shell composite structures will be adopted followed by external surface modification by silanes to achieve hydrophobicity. The materials will be characterized by x-ray diffraction, scanning and transmission electron microscopy, thermo-gravimetric and gas chromatography-mass spectrometry, etc. The mechanisms of synthesizing zeolite 13X@SiO2 composites will be investigated, followed by optimizing the silylation processes of preparing hydrophobic zeolite composites. Finally, the kinetics and thermodynamics of gas separation processes will be also discussed. The capture cost will be decreased dramatically using the as-synthesized hydrophobic zeolites as adsorbents, which has important theoretical and practical significance for the reduction of greenhouse gases emission.

针对沸石13X在高湿烟道气中受水蒸气影响分离CO2失效的问题，本课题拟对一种新型疏水型核壳沸石13X@SiO2进行探索研究。拟首先在沸石表面包覆一层具有丰富羟基的壳层材料，再采用有机硅烷对核壳沸石进行硅烷化改性，获得一种兼具高疏水性、高CO2吸附性能的新型疏水型核壳沸石13X@SiO2。借助XRD、SEM、TEM、TGA、气相色谱质谱联用仪等先进测试手段，深入探索核壳沸石13X@SiO2的形成机理，探明硅烷化条件对疏水型核壳沸石结构、性能的影响机制，对其动态分离高湿CO2的吸附热力学及动力学进行系统研究，为利用疏水型核壳沸石为吸附剂变压吸附分离高湿烟道气中CO2提供理论依据和技术支撑。本课题的成功实施将大大降低变压吸附捕集CO2技术在燃煤电厂等高湿CO2排放源的应用成本，对于CO2温室气体的减排具有重要的理论和实际意义。