【作者】 胡敏；

【导师】 姚虎卿； 梅华；

【作者基本信息】 南京工业大学 ， 化学工程， 2005， 硕士

【摘要】 硫醇普遍存在于大多数石油产品中,不仅具有恶臭,而且对于金属有较强的腐蚀性,同时也是一种自由基引发剂,严重影响油品的质量和安定性。因此,有必要将硫醇从石油产品中脱除。广泛应用的Merox 液-液脱硫醇法虽然是一种优良的脱硫醇方法,但脱臭过程中有大量废碱液排放,污染环境,且处理成本昂贵。因此在日益重视环境保护的今天,减少甚至取代该工艺中的液体碱,已成为重要的研究课题。而固体碱催化剂的使用可以避免大量废碱液的排放,并且具有与环境友好、产物易分离、反应条件温和、高选择性、无腐蚀等优点而日益受到人们的重视。本论文以氧化镁、氧化铝为原料制备镁铝复合氧化物固体碱催化剂,浸渍法负载活性组分磺化酞菁钴（CoPcS）制备固体碱脱硫醇催化剂,并在硫醇催化氧化反应中评价催化剂的活性,通过XRD、CO₂-TPD、FTIR、BET、SEM和XPS表征催化剂,讨论了不同的制备方法、不同镁铝比、活性组分磺化酞菁钴（CoPcS）的负载量、不同浸渍溶剂、助催化剂NiO、Fe₂O₃、CuO对催化剂活性和稳定性的影响。最后将催化剂应用于工厂液化气侧线脱硫醇过程,取代原有的液碱洗和水洗工艺,以观察该催化剂的催化寿命。在此基础上探讨在液化气脱硫醇过程中该催化剂的失活机理,为催化剂的再生和工业化应用作准备。通过研究得到以下结论: 1. MgO/Al₂O₃-CoPcS催化剂（由混合、浸渍法制备）相较于Mg（Al）O-CoPcS催化剂（由共沉淀、浸渍法制备）,在硫醇催化氧化反应中不仅具有较高的催化活性和稍好的催化寿命,并且在空气中具有较好的稳定性,不易吸附空气中的CO₂和H₂O而降低活性。MgO/Al₂O₃固体碱催化剂中Mg/Al摩尔比（即MgO和Al₂O₃的相对含量）对催化剂的催化活性影响较大。随着MgO含量的增加,催化剂表面的碱性增加,催化剂活性提高。但具有较高Mg/Al摩尔比的催化剂在空气中的稳定性相对较差。2. 活性组分CoPcS的负载量直接影响MgO/Al₂O₃-CoPcS催化剂的催化活性。更多还原

【Abstract】 A series of Mg-Al mixed oxide solid bases were prepared in this paper. After supported sulfonated cobalt phthalocyanine （CoPcS） the catalytic performance of these catalysts was evaluated in the mercaptan oxidation reaction. The samples were characterized by X-ray diffraction （XRD）, CO₂ temperature-programmed desorption （CO₂-TPD）, FTIR, surface area measurement （BET）, scanning electron microscope （SEM） and X-ray photoelectron spectroscopy （XPS）. The effect of preparation method, Mg/Al mole ratios, loading content of CoPcS, impregnation solutions and co-catalyst NiO, Fe₂O₃, CuO was discussed. The MgO/Al₂O₃-CoPcS catalyst was applied to the sweetening of liquefied petroleum gas （LPG） instead of the alkali and water washing process to observe the lifetime of the catalyst. On the base of the above research the deactivation mechanism of MgO/Al₂O₃-CoPcS catalyst during the sweetening of LPG was discussed which made preparations for the regeneration and industrial application of the catalyst. The experimental results show that: 1. MgO/Al₂O₃-CoPcS catalyst （prepared by mixing method） not only shows a better catalytic activity and lifetime in mercaptan oxidation reaction but has a better stability in air than Mg（Al）O-CoPcS catalyst （prepared by precipitation method）. Mg/Al mole ratio has a great effect on the activity. The catalytic activity is improved with the increase of Mg/Al mole ratio. However, the catalyst with high Mg/Al ratios is easier to adsorb CO₂ and H₂O in air, which results into the declining of the activity. 2. The loading content of CoPcS has an obvious effect on the catalytic activity of MgO/Al₂O₃-CoPcS catalyst. With the increase of CoPcS content the oxidation rate is accelerated. But the activity decreases as CoPcS content is overfull. In this paper the appropriate loading content of CoPcS is 1%. 3. MgO/Al₂O₃-CoPcS catalyst impregnated in methanol solution shows better catalytic activity than the catalysts impregnated in ethanol or water. MgO content in the catalyst has changed into Mg（OH）2 when the impregnation solution is water, which results into the great loss of the amount of basic sites. 4. MgO/Al2O3-CoPcS catalyst shows high initial activity and good stability in the application of sweetening of LPG. XRD、CO2-TPD、SEM and BET results reveal that the deactivation mechanism of catalyst is as follows: firstly the basic sites on the catalyst surface are poisoned by the acidic materials such as hydrogen sulfide in LPG. Secondly, the catalyst is poisoned by reaction product dithio-ether and reactant mercaptan. Thirdly, heavy oil and residual blocks the micropores of the catalyst, which results into the loss of surface area and speeds up the deactivation rate of catalyst. 5. Addition of NiO, CuO or Fe2O3 contributes to the improvement of the catalytic activity of MgO/Al2O3-CoPcS. The proper addition amount of the co-catalyst is 5～15 wt% （NiO）, 4～8 wt%（CuO） and 4～14 wt%（Fe2O3）. NiO or CuO increases the activity of the catalyst by increasing the basicity of the catalyst surface. However, the amount of basic sites and oxidation ability both increase as Fe2O3 is added in.更多还原