【作者】 郭天祥；

【导师】 张谦温； 高俊斌；

【作者基本信息】 北京化工大学 ， 化学工程与技术， 2011， 硕士

【摘要】 随着我国经济的快速发展,市场对以乙烯和丙烯为代表的低碳烯烃的需求增长迅速,目前乙烯和丙烯的生产主要是通过蒸汽裂解技术,然而,随着丙烯衍生物需求量的激增,通过蒸汽热裂解的方法联产得到的丙烯产量已不能满足国内外市场上对丙烯日益增长的需要,此外,蒸气热裂解技术还存在着能耗和设备投资过高、裂解原料操作弹性差、环境污染较严重等问题,催化裂解技术发展可以很好地解决以上问题,因此催化裂解技术成为研究的热点,其核心主要是催化剂及其催化裂解工艺。本文合成了高岭土微球基质表面附晶生长ZSM-5的复合分子筛,并对其进行了XRD、SEM、NH3-TPD、BET表征；在小型固定床微反实验装置上,对该复合分子筛及其它机械混和分子筛/高岭土催化剂的催化裂解反应性能进行了考察,旨在探索和开发出一种多产低碳烯烃的催化剂。首先,以水玻璃、硫酸铝、正丁胺、浓硫酸等为原料通过水热合成出了ZSM-5分子筛,考察了ZSM-5分子筛合成条件的影响,详细考察了晶化温度、晶化时间、pH值、硅铝比、模板剂用量、n(H2O)/n(SiO2)比的影响,结果表明,当pH值为10,硅铝比为60,晶化时间为24h,晶化温度为180℃, n(H2O)/n(SiO2)=30,模板剂用量为5.5ml时,可以合成出较高结晶度的ZSM-5分子筛。其次,合成得到了高岭土微球基质的表面附晶生长ZSM-5复合分子筛,通过XRD、SEM、NH3-TPD、BET方法对附晶分子筛进行了表征,表征结果表明,在高岭土微球上成功地生长了更加微小的ZSM-5晶粒,大小约为3μm,成功地合成出了一种廉价的具有多级孔道结构的新型催化裂解催化剂。第三,在小型固定床微反实验装置上,以直馏柴油为反应原料进行了催化裂解微反活性评价实验,分别考察了HZSM-5、Hβ、HY分子筛与高岭土微球(WQ)机械混和催化剂及高岭土附晶ZSM-5复合催化剂在不同反应温度下的反应性能。结果发现从低碳烯烃收率来看,高岭土附晶ZSM-5复合分子筛>高岭土和ZSM-5分子筛机械混和催化剂>Hβ分子筛机械混和催化剂>高岭土和HY分子筛机械混和催化剂。第四,在小型固定床微反实验装置上,考察了不同类型分子筛、不同硅铝比的ZSM-5分子筛及高岭土附晶ZSM-5复合分子筛对正丁烷原料的催化裂解反应性能,并考察了不同质量空速及反应温度对产品分布的影响。结果表明：高岭土附晶ZSM-5复合催化剂的反应性能最好,在反应条件为：原料气质量空速为5h-1；反应温度为600℃时,正丁烷的转化率达到了89.71%,低碳烯烃收率达到40.46%,干气收率为38.49%。更多还原

【Abstract】 With developing our country economy fast, the requirement of the market for ethylene and propylene is growing rapidly. At present, the ethylene and propylene are producted by steam thermal cracking. However, the production of propylene by stream thermal cracking has been unable to meet with the growing market for the needs of propylene. In addition, there are still problems for steam thermal cracking. For example, energy consumpting and equipment investment is too high, the materials of cracking could choose the range of small, the environmental pollutions seriously and so on. Catalytic cracking technology could solve the above problems, so catalytic cracking technology is becoming a hot research, mainly in terms of process and catalyst.In this article ZSM-5 zeolite is synthesized on the surface of Kaolin microspheres successfully, and it was characterized by XRD、SEM、NH3-TPD、BET. It was studied in a small experimental device of fixed-bed microreactor with other catalysts of mechanical mixing zeolite/Kaolin, in order to explorate and develop a catalyst for light olefins.The first, ZSM-5 zeolite is synthesized in the hydrothermal system by the materials of waterglass,aluminumsulfate, butylanmine, sulfuric acid. The impact of ZSM-5 zeolite synthesis conditions is studied, studied in detail in the crystallization temperature, crystallization time, pH, Si/Al, the amount of template, the concentration. The results show that a higher crystallinity ZSM-5 zeolite can be synthesized, as the pH is 10, the Si-Al ratio is 60, the crystallization time is 24h, crystallization temperature is 180℃, n(H2O)/n(SiO2)=30, the amunt of template is 5.5ml.The second, ZSM-5 zeolite grew successfully on the surface of Kaolin microsphers, the ZSM-5 overgrowth on Kaolin was characterized by XRD、SEM、NH3-TPD、BET. The characterization results showed that the surface of Kaoline grew more microscopic crystal of ZSM-5, it is about 3μm, a new catalytic cracking catalysts with an inexpensive multi-channel had been successfully synthesized.The third, a diesel raw material occurred catalytic cracking in the small fixed bed micro-reactor, HZSM-5/WQ. Hβ/WQ.HY/WQ mechanical mixed catalysts of 5% 10% 15% three content mass fraction were studied at 500℃、550℃、600℃. The reactivity of the ZSM-5 overgrowth on Kaolin was studied at 500℃、550℃、600℃.The results showed that:The yield of propylene, the ZSM-5 overgrowth on Kaolin>ZSM-5/WQ mechanical mixed catalysts>β/WQ mechanical mixed catalysts>Y/WQ mechanical mixed catalysts.The forth,in the small fixed bed micro-reactor, n-butane as the reaction to raw materials, the gas speed in the raw materials and the temperature of reaction were studied on catalytic cracking reaction. Under certain conditions, compared to thermal cracking with quart sand as filler and catalytic cracking, the results showed that the ZSM-5 overgrowth on Kaolin had the best reaction performance. The optimal reaction condition was at mass flow speed of the n-butane 5h-1 and 600℃. The conversion was 89.71% at mass flow speed of the n-butane 5h-1 and 600℃, the yield of light olefins reached 40.46%, the yield of dry gas reached 38.49%.更多还原