凹土基5A分子筛的合成及正构烷烃吸附分离的研究

发布时间：2018-03-17 17:28

  本文选题：凹凸棒土　切入点：A分子筛　出处：《石油化工》2017年09期 　论文类型：期刊论文

【摘要】：以廉价易得的凹凸棒土为原料,采用水热合成法,通过优化原料配比、晶化温度和晶化时间等条件,制备了凹土基5A分子筛吸附剂。采用XRD、SEM、N_2吸附-脱附等方法对合成的5A分子筛微观结构进行表征;并应用于正构烷烃的吸附分离,测定了吸附正己烷(n-C_6)和正庚烷(n-C_7)有机蒸汽的静态吸附速率曲线和吸附等温线。表征结果显示,合成的5A分子筛中既有微孔又有一定的中孔,晶体颗粒直径达到纳米级,呈现规整的立方晶体形貌。实验结果表明,在n(SiO_2)∶n(Al_2O_3)=2.3、n(Na_2O)∶n(H_2O)=12∶600(试样B)、晶化温度为85℃、晶化时间为4 h的条件下,制备的5A分子筛晶粒更加规整、比表面积更大、吸附速率更快,对n-C_6,n-C_7的静态饱和吸附量最大,分别为149 mg/g和144 mg/g。
[Abstract]:Using attapulgite which is cheap and easy to get as raw material, hydrothermal synthesis method was adopted, and the conditions such as ratio of raw material, crystallization temperature and crystallization time were optimized. The adsorbents of attapulate-base 5A molecular sieve were prepared. The microstructure of the synthesized 5A molecular sieve was characterized by XRDX SEMN _ 2 adsorption-desorption, and applied to the adsorption and separation of n-alkanes. The static adsorption rate curves and adsorption isotherms of adsorbed n-hexane n-C6) and n-heptane n-C7) organic vapor have been determined. The characterization results show that the synthesized 5A molecular sieve has both micropores and mesoporous pores, and the diameter of crystal particles reaches nanometer level. The morphology of cubic crystal is regular. The experimental results show that under the conditions of nSiOS-2: Al2O3 / 2. 3 / nNa2O3: nA2O1: 12: 600 (sample BU, crystallization temperature is 85 鈩，

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