【作者】 张丽；

【导师】 魏小兰； 徐雪青；

【作者基本信息】 华南理工大学 ， 化学工程， 2012， 硕士

【摘要】 吸附式干燥因具有高的干燥速率，低的能源消耗，显著的节能优势和品质保持功能而被作为干燥除湿设备中的首选干燥方式。其中除湿器是干燥设备中的心脏元件，而决定除湿器除湿效率的核心部件是负载有高效除湿材料的转轮芯。为了达到高效的除湿效率要求除湿材料必须具有以下优点：1.为拓展吸附式除湿设备的应用领域，要求水吸附材料能够在相对湿度低于20%的环境中仍然具有良好水汽吸附性能。2.为提高除湿设备的除湿效率，要求水吸附材料必须在高相对湿度环境也具有大的吸附能力。3.为降低吸附除湿能耗，要求水吸附材料能够在不高于100°C的条件下，快速高效脱附。4.为使水吸附材料可以在长时间的水热热湿交变服役环境下保持高效的除湿效果，要求材料具有良好的水热稳定性。以上四个条件缺一不可。为了更加满足吸附式设备对除湿材料的要求，本文先采用沸石纳米自组装法在碱性条件下来合成了硅铝材料。用N2吸附-脱附来表征样品的比表面积、孔径分布和孔容；TEM、SEM观察样品孔道结构和形貌的孔道分布；XRD了解样品内部孔道有序度和孔壁的晶化程度；IR获知样品的骨架结构；使用化学分析法和XPS来分别测定样品主要元素含量和表面元素含量与元素的组成状态；用DVS和重量法测定样品在25°C不同湿度下的吸附-脱附和再生性能；用水热处理测定所合成材料的稳定性。结果显示，合成的硅铝材料含有有序的微孔和介孔的多级孔结构，且其比表面积高达1010m2·g1。对合成过程中原料硅铝比、微晶化过程中微晶化时间和微晶化温度的研究，探索出了最佳的合成条件。当硅铝比较低、微晶化时间较短和微晶化温度较低时，合成的多级孔结构材料的吸附水性能在相当湿度RH为30%和90%时分别高达214.6mg·g1和552.9mg·g1。在相对湿度RH小于20%时，该材料的吸附水汽性能明显好于3A型、MCM-41和SBA-15；在相对湿度RH大于30%，合成材料的吸附水汽性能是3A型的2倍；由于样品的脱附活化能小，再生温度低，它可利用普通的太阳能进行再生；同时该合成的材料还具有良好的水热稳定性。为了使材料的水热稳定性增加，本课题在以上的合成过程中还采用水蒸气辅助来使孔壁晶化，从而达到长的使用寿命的目的。通过改变蒸汽温度和硅源，研究出了最佳的合成条件。XRD显示合成的材料不仅存在明显的高度有序的微孔和介孔，且还存在晶化了的孔壁。当相对湿度低于30%时，等温水吸附曲线说明在蒸汽辅助下制备的材料具有很好的水吸附能力，它是只采用沸石纳米自组装法合成的材料的2倍，是传统的3A型沸石分子筛的3倍。更多还原

【Abstract】 Due to high drying rate, low energy consumption, a significant energy-saving advantages and maintaining the quality in the adsorption drying, the adsorption drying is as the preferred drying method for drying dehumidification equipment. The dehumidifier is the heart of the element in drying equipment, while the core member deciding dehumidifier dehumidifying efficiency is the runner core being loaded with efficient desiccant material. In order to achieve efficient dehumidification efficiency the desiccant material must have the following advantages:1. For expanding the application fields of the adsorption type dehumidifying equipment, the water adsorbent material is still having a good water vapor adsorption performance in the environment of relative humidity lower than20%.2. For the purpose of enhancing the dehumidifying efficiency of the dehumidifying device, water adsorbent material must have a large adsorption capacity in a high relative humidity environment.3. In order to reduce energy consumption in desiccant, it requires that the water in adsorbent material is rapidly and efficiently desorbed under the conditions of not higher than100℃.4. The efficient dehumidification effect can be maintained under the service environment of the prolonged water chattering and wet alternating, it is necessary that the materials have good hydrothermal stability. The above four conditions are indispensable.More to meet the requirements of desiccant material in the adsorption equipment, the zeolite nano self-assembly were used in this paper to synthesis low ratio of Si and Al of materials in alkaline conditions. N2adsorption-desorption characterized the surface area, pore size distribution and pore volume; The TEM and SEM observed the structure of pore and morphology; XRD understood ordered degree in internal pore of the sample and the degree of crystallization of the pore walls; IR informed of the skeletal structure of the sample; Chemical analysis method evaluated the content of major elements in the sample; XPS measured chemical composition and chemical state of the surface of the sample; DVS and gravimetric method determined water vapor adsorption and regeneration of samples at25℃in different relative humidity; TPD calculated the desorption activation energy of sample; The hydrothermal treatment knew the stability of the synthesized material. The results showed the low Si/Al materials had micro porous and mesoporous order structure, and their specific surface area were up to1010m2·gH1. The optimal synthetic conditions were discovered by altering raw ratio of Si and Al, time of microcrystalline, and temperature of microcrystalline in the synthesis process. When the aluminosilicate was relatively low, the time of microcrystalline shorter and temperatures of microcrystalline lower, the performance in water of adsorption for the synthetic material of the multi-stage pore structure in a considerable humidity RH of30%and90%was respectively up to214.6mg·gH1and552.9mg·gH1. When the relative humidity RH was less than20%, the performance of the adsorption of water vapor of the material was significantly better in the3A-type, MCM-41and SBA-15; the relative humidity RH was greater than30%, the performance of the adsorption of water vapor of the synthetic material was two times as many as3A-type; The activated energy of desorption on the sample was small, the regeneration temperature was low, it could use a common solar to regenerate; At the same time the synthetic material also had good hydrothermal stability.In order to increase the hydrothermal stability of the material, in the above synthesis process, the subject also used steam-assisted to enhance crystallization of hole wall, so as to achieve a long service life. The optimum synthesis conditions were developed by changing the temperature of vapor and the silicon source. XRD showed that the synthetic material was not only highly ordered micro porous and mesoporous structure, but also existed the hole wall of crystallization. When the relative humidity was below30%, the sorption isotherm explained the materials prepared in the steam assisted had a good water adsorption capability, whose capability was two times as many as A-type zeolite the synthetic material by only using zeolite nano-assembly method, and three times as many as A-type zeolite the traditional type3A zeolite molecular sieve.更多还原