硅胶和改性硅胶的吸附解吸特性  

ADORPTION AND DESORPTION PROPERTIES OF SILICA GEL AND MODIFIED SILACA GEL

作　　者：刘岩 马春元 张梦 LIU Yan;MA Chunyuan;ZHANG Meng(School of Energy and Power Engineering,Shandong University,National Engineering Laboratory of Coal-fired Pollutants Emission Reduction,Jinan 250061,China)

机构地区：[1]山东大学能源与动力工程学院燃煤污染物减排国家工程实验室,济南250061

出　　处：《离子交换与吸附》2018年第4期289-297,共9页Ion Exchange and Adsorption

基　　金：国家自然科学基金（21307075）;国家重点研发计划（2017YFB0602902）.

摘　　要：硅胶-水工质对以清洁环保、解吸温度低等优势广泛应用于太阳能吸附式制冷系统中,采用浸渍法对硅胶进行改性,通过电子扫描显微镜（SEM）观察细孔（A型）、中孔（B型）、粗孔（C型）和复合（C型/CaCl2）硅胶的表面形貌,采用称重法测定硅胶-水的吸附等温线,采用程序升温脱附技术测定水分子在硅胶上的脱附曲线并计算水的脱附活化能和脱附热。实验结果表明,A型硅胶在较低相对湿度下易吸附,C型硅胶在较高相对湿度下易吸附,B型硅胶介于两者之间,CaCl2的嵌入使C型/CaCl2硅胶表面更加粗糙且其吸附量明显增大。当相对湿度为70%时,C型硅胶的脱附活化能和脱附热最小,C型/CaCl2硅胶的吸附量最大。对于太阳能吸附式制冷系统,在太阳能充足地区可提供的热量较多,选取吸附量最大的C型/CaCl2硅胶作为吸附剂;在太阳能不充足的地区,选取脱附活化能和脱附热最小的C型硅胶作为吸附剂。Silica gel-water working fluid pairs is widely used in solar adsorption refrigeration system with the characteristics of clean and environmental protection and low desorption temperature. The method of impregnation is used to modify the silica gel. The surface morphology of micropore （type A）, mesopore （type B）, macropore （type C） and recombination （type C/CaCl2） silica gel were observed by scanning electron microscope （SEM）. The adsorption isotherms of silica gel were measured by weighing method. The desorption curves of water on silica gel were measured by the temperature programmed desorption and the desorption activation energy and desorption heat of water were calculated. The experimental results show that the type A silica gel is easy to adsorb at low relative humidity, and the type C silica gel is easy to adsorb at high relative humidity, and the type B silica gel is in between. The surface structure of type C/CaCl2 silica gel has became rougher and its adsorption is significantly increased with the immersion of CaCl2. While the relative humidity is 70%, the desorption activation energy and desorption heat of C type silica gel are the lowest, and the adsorption capacity of C/CaCl2 silica gel is the largest. For the solar adsorption refrigeration system, the type C/CaCl2 silica gel with maximum adsorption is selected as adsorbent in areas with sufficient solar energy, and the type C silica gel with the smallest desorption activation energy and desorption heat is selected as adsorbent in areas with insufficient solar energy.

关 键 词：硅胶-水 吸附等温线 脱附曲线 脱附活化能 脱附热 

分 类 号：TK511.3[动力工程及工程热物理—热能工程]