太阳能吸附制冷用复合吸附剂制备及其吸附机理探讨

PREPARATION AND ADSORPTION MECHANISM OF COMPOSITE ADSORBENTS ON SOLAR POWERED ADSORPTION REFRIGERATION

以乙醇为吸附质,选取13X分子筛、凹凸楱土和氯化锶等为主要吸附材料,通过混合法制备了一系列有着优良吸附能的复合吸附剂。测定了乙醇在主要吸附材料和自制复合吸附剂上的吸附量,用TG DTA法对主要吸附材料的热稳定性和自制吸附剂DTA脱附乙醇峰端温度进行了分析。对吸附剂原料复合比例和扩孔剂种类等制备条件进行了实验研究。结果表明:自制复合吸附剂比单一吸附材料对乙醇有着更大的吸附能力;DTA分析的脱乙醇峰端温度明显低于单一吸附材料;加入扩孔剂E1或E2,可增加自制复合吸附剂孔容和孔径,改善其吸附性能;自制复合吸附剂对乙醇的吸附量显著高于活性炭。其中,M4 0003和M1 0001复合吸附剂对乙醇的平衡吸附量约为活性炭的2 5～4倍;M1 0001—乙醇工质对的吸附制冷量是活性炭—乙醇的2～6倍。对吸附剂复合的机理初步探讨表明:增加复合吸附剂弱吸附中心数,可降低其脱附温度。

Alcohol as adsorbate, 13x molecular sieve, concavo-convex earth and strontium chloride as main adsorption materials, a series of composite adsorbents with excellent adsorption performance were prepared through mixed method. Adsorption capacities of self-regulating composite adsorbents for alcohol were determined. Thermal stability of main adsorption material and desorption peak temperature of self-regulating composite adsorbents for alcohol were analyzed by TG-DTA method. Preparation conditions, such as composite proportion of adsorption material and varieties of pore size expanding, were experimentally researched. The results showed that: adsorption capacities of composite adsorbents made of several kinds of adsorption material are bigger than that of single adsorption material. Adding pore size extenders, such as El or E2, pore volume and pore size of the composite adsorbents could be increased, and adsorption capacities were improved. Adsorption capacities of self-prepared composite adsorbents for alcohol are higher than that of activated carbon. Adsorption capacities of the composite adsorbents of M4-0003 and MI-0001 for alcohol are about 2.4-4 times than that of activated carbon. Adsorption cooling volume of Ml-0001 for alcohol are about 2-6 times than that of activated carbon for alcohol. Peak temperature of desorption alcohol of composite adsorbents is lower than that of single adsorption material. Preliminary study on the composite mechanism of absorbents showed that the numbers of weak adsorption centers increase with lowering desorption temperature of the composite adsorbents.