摘要
以硅溶胶和十八水硫酸铝为硅铝源,按 n(Na_2O):n(Al_2O_3):n(SiO_2):n(H_2O)=16:1:16:210配制具有高稳定性、高活性和高流动性的液态导向剂。导向剂老化特定时间后,加入一定最的稀硫酸溶液,在强搅拌条件下制成 FAU 型沸石合成凝胶。该凝胶于373 K 下进行晶化,在α-Al_2O_3载体的外表面合成了较小晶粒的 FAU 型沸石膜。用X射线衍射和扫描电子显微镜表征FAU 型沸石膜的晶体结构和表面形貌。通过渗透蒸发实验研究 FAU 型沸石膜的孔道结构对其传递特性的影响。实验研究表明,高活性导向剂是 FAU 型沸石膜在载体表面进行生长的主要原因。导向剂的老化时间、老化温度和加入量对 FAU 型沸石膜的表面形貌、晶体尺寸和渗透性能的影响较大。较长的老化时间、较低的老化温度和较大的导向剂加入量均有利于小晶粒 FAU 型沸石膜的生成。渗透蒸发实验结果表明,小晶粒 FAU 型沸石膜在提纯1,3-丙二醇的过程中具有比大晶粒膜更高的1,3-丙二醇/丙三醇的分离选择性。
Liquid crystallization directing-agent with high stability, high activity and good fluidity for FAU type zeolite crystallite was first prepared from silica sol and Al2（SO）3 · 18H2O by keeping n（Na2O） ： n（Al2O3） ： n（SiO2） ： n（H2O） at 16 ： 1 ： 16 ： 210. After aging for a specific period, at a specific temperature, appropriate amount of diluted sulfuric acid solution was added into the above directing-agent under stirring to form a uniform gel for FAU type zeolite membrane. At 373 K, FAU type zeolite membrane was prepared on a pretreated α-Al2O3 tubular support. XRD and SEM were used to investigate crystal structure and morphology of the membrane. Single-gas permeation test was designed to study permeation properties of the membrane. Results indicated that directing-agent is decisive factor for growth of membranes. Aging time, aging temperature and adding amount of directing-agent strongly influence the morphology, crystal size and permeation property of the membrane. Prolonging aging time, lowering aging temperature and increasing amount of crystallization directing agent are preferable to synthesize FAU type zeolite membrane. According to pervaporation experiment, FAU type zeolite membrane exhibits much higher 1,3-propanediol/glycerol separation selectivity than membrane of larger crystals.
出处
《石油化工》
EI
CAS
CSCD
北大核心
2008年第10期1009-1014,共6页
Petrochemical Technology
关键词
FAU型沸石膜
膜分离
渗透蒸发
导向剂
FAU type zeolite membrane
membrane separation
pervaporation
directing-agent
