【作者】 周二鹏；

【导师】 赵地顺；

【作者基本信息】 天津大学 ， 工业催化， 2008， 博士

【摘要】 随着人们环保意识的不断增强及原油硫含量的增大,汽车尾气所带来的污染越来越成为人们关注的焦点,生产满足环境保护要求的清洁燃料汽油越来越重要,所以世界各国对燃料油品中的硫含量提出了非常严格的要求。与其他脱硫技术相比,氧化脱硫新技术可以在常温常压,不消耗氢气的条件下使用;另外,还能够有效的脱除传统方法较难脱除的噻吩类硫化物,并且具有脱氮功能;反应副产物为有机硫化物,可以作为潜在的工业原料;反应过程中二氧化碳排放量少,系环保型工艺过程,因此具有广泛的应用前景。本文通过石家庄炼油厂生产的FCC汽油含硫化合物的检测,制定了以H₂O₂为氧化剂,杂多酸或有机酸为催化剂,在季铵盐相转移催化剂的作用下的催化氧化脱除模型化合物中噻吩的研究方案。对季铵盐相转移催化剂阴阳离子及其结构对氧化脱硫率的影响进行了系统研究,提出在季铵盐相转移催化剂作用下噻吩的氧化机理及最终产物,模型化合物脱硫率达到93.1%。以噻吩为模型化合物,在自制杂多酸季铵盐催化下,以H2O2为氧化剂,对模型化合物氧化脱除噻吩工艺进行了系统研究。自制催化剂具有较高的催化氧化活性,能够有效减小反应系统相间阻力,促进噻吩的氧化反应顺利进行。提出了该催化剂催化氧化脱除模型化合物中噻吩的反应机理。以噻吩为模型化合物,自制铁酸锌负载磷钨酸为催化剂,以H2O2为氧化剂,对模型化合物氧化脱除噻吩工艺进行了系统研究。负载型磷钨酸催化剂催化活性中心突出,分布均匀,克服了磷钨酸直接作为催化剂比表面小,反应后不易回收等缺点。通过对模型化合物氧化脱除噻吩的研究分析,制定了FCC汽油以H₂O₂为氧化剂,杂多酸或有机酸为催化剂,在季铵盐相转移催化剂的作用下的氧化脱硫实验方案。季铵盐类相转移催化剂能够降低水油两相间的相间阻力,其阳离子还能与过氧杂多阴离子结合,避免了溶剂化效应,提高了杂多酸催化剂的催化活性;确定了相转移催化氧化脱除FCC汽油中含硫化合物的反应机理及最终产物,FCC汽油脱硫率达到83.6%。更多还原

【Abstract】 A considerable attention had been focused on automobile-exhaust pollution due to the increasingly content of sulfur in crude oil and the recognition of environmental consciousness. Strict regulations limiting the sulfur content had been introduced in some countries. Conventional hydrodesulfurizaiton technology if used for this process needed severe operating conditions, such as high hydrogen pressure and reaction temperature, which were unfavorable for commercial purpose. Much interest, therefore, had been focused on oxidative desulfurization technology, which could be operated on moderate conditions and reaction could be processed without consuming hydrogen. In addition, it had following advantages: (1) the nitrogen compounds and substituted thiophenes could be removed; (2) the side-product was organic sulfide, which may be used as industrial material; (3) it was an environment protection technique due to the decreasing emission of carbon dioxide.In this text, the oxidative desulfurization of thiophene as a model compound was studied over the system combined by the catalyst of heteropoly acids, the oxidant H2O2 and quaternary ammonium salt phase-transfer catalyst. The influence of cation of quaternary ammonium salt phase-transfer catalyst and the structure on the oxidative-desulfurization rate was investigated. It was shown that the desulfurization rate was up to 93.1%. The oxidation mechanism of thiophene and the final product of oxidative desulfurization were discussed.The processing conditions of oxidative desulfurization of thiophene were studied over the system combined by catalyst of heteropoly acids- quaternary ammonium salt, and the oxidant H2O2. The results showed that the catalyst was active because it could decrease the interfacial resistance and facilitate the oxidative desulfurization. The processing conditions of oxidative desulfurization of thiophene were investigated over the system combined by catalyst of zinc ferrite supporting on phosphotungstic acid, and the oxidant H2O2. It was shown that the active centre of catalyst was increased and distributed equably by increasing the specifics surface area of catalyst.According to the above analysis, the oxidative desulfurization of FCC was studied over the system combined by the catalyst of heteropoly acids, the oxidant H2O2 and quaternary ammonium salt phase-transfer catalyst. It was shown that the desulfurization rate was up to 83.6%. Quaternary ammonium salt phase-transfer catalyst could decrease the resistance of water-oil interface; its cation could combine with over-oxygen-heteropoly anion, and avoid the solvent effect, thus the activity of heteropoly acids catalysts increased. The oxidation desulfurization mechanism of FCC and the final product were determined.更多还原