【作者】 王亮；

【导师】 李春虎；

【作者基本信息】 中国海洋大学 ， 海洋化学工程与技术， 2011， 博士

【摘要】 世界各国对柴油中硫含量的法规限制日益严格,所以柴油的深度脱硫已经成为重要的研究课题。目前降低柴油中硫含量的方法主要有加氢脱硫和非加氢脱硫,加氢脱硫（HDS）技术能够有效地脱除柴油中大部分含硫化合物,但是很难脱除二苯并噻吩及其衍生物,因此,世界各国致力于开发新的脱硫技术。其中,氧化脱硫因其具有反应条件温和、非临氢操作等特点,被认为是最有前途的脱硫技术。本文中选用鄂尔多斯半焦作为催化剂载体,催化剂采用等体积浸渍法制备,即将具有keggin结构的磷钨酸负载在活化后的半焦之上制备成磷钨酸/半焦催化剂,并采用BET、FTIR、NH3-TPD、XRD、SEM和TG-DTA等分析手段对负载型磷钨酸催化剂进行比表面、孔结构和酸强度、晶相结构和热稳定性等表征。然后以磷钨酸/半焦为催化剂,30%H₂O₂为氧化剂,span60为表面活性剂,对FCC柴油中的有机含硫化合物进行催化氧化脱除。考察了反应温度、反应时间、氧化剂用量、催化剂用量和表面活性剂用量等操作条件对脱硫率的影响,用微库伦仪测定FCC柴油的脱硫率来评价催化剂的催化活性,用气相色谱测定氧化脱硫前后FCC柴油中含硫化合物成分的变化,同时探索了连续化操作条件下FCC柴油的氧化脱硫规律,最后,对模型化合物DBT的氧化脱硫条件进行了优化,并初步讨论了DBT和FCC柴油的氧化反应动力学。表征结果表明:催化剂的keggin结构保持不变;磷钨酸以微晶粒子簇状态高度均匀分散在载体表面或者进入到孔道内部;催化剂酸强度随着负载量的增加有所增加;催化剂有很好的热稳定性。通过对FCC柴油进行氧化脱硫研究,得出FCC柴油脱硫率影响因素的主次顺序为:氧化剂用量>HPW/Sc2用量>反应时间>反应温度>Span60用量;从而得到最佳氧化反应条件为:反应温度为60℃,反应时间为60min,HPW/Sc2用量为1wt.%,氧化剂用量[H₂O₂]/[S]=3,Span60为0.36wt%。对氧化后的FCC柴油采用萃取方法脱除其中含硫化合物,选择90%的NMP作为萃取剂,对萃取比（萃取剂和FCC柴油的体积比）、萃取温度、萃取时间等影响因素进行考察,通过研究得出萃取反应的最佳操作条件为萃取比1:1、萃取时间10min、萃取温度25℃,此时,FCC柴油脱硫率79.38%,收率为98%;对氧化后的FCC柴油采用吸附方法脱除其中含硫化合物,选择CuO作为脱硫剂,脱硫率可以达到86.03%。模型化合物的氧化脱硫研究表明,芳烃、烯烃和含氮化合物对模型化合物的脱除存在影响,其影响顺序是:喹啉>环乙烯>苯,模型化合物的反应活性顺序为:DBT>4,6-DMDBT>BT,且DBT和FCC柴油的氧化反应均表现为一级反应动力学。对于HPW/Sc2催化剂和回收的HPW/Sc2催化剂运用SEM、FT-IR、UV-Vis DRS进行表征。结果表明:再生的催化剂与新鲜的催化剂有着相一致的红外谱图和紫外谱图,再生的催化剂仍保持着的keggin结构,并且再生的催化剂具有跟新鲜催化剂相近的催化活性;萃取剂NMP通过蒸馏回收再利用,与新鲜萃取剂相比,经回收后的NMP,脱硫率下降6.5%。更多还原

【Abstract】 Deep desulfurization of diesel has become an important research subject due to the increasing regulations of reducing sulfur content in most countries. At present, the main adopted way to reduce sulfur content in diesel is hydrodesulfurization （HDS） and non-hydrodesulfurization, hydrodesulfurization （HDS） can effectively remove the majority of sulfur-containing compounds in diesel, but it is difficult to remove DBT and its derivatives. Therefore, the world is devoted to the development of new technologies, among them, Oxidative desulfurization is considered to be one of the most promising desulfurization methods for its mild reaction condition and high efficiency.In this study, the lignite semi-coke from Ordos Inner Mongolia is selected as carrier to prepare catalysts, phosphotungstic acid /semi-coke, phosphotungstic acid supported on semi-coke with various phosphotungstic acid loading, are prepared by impregnation, In addition, BET、FTIR、NH3-TPD、XRD、SEM and TG-DTA are employed to analyze the surface area, pore structure, functional groups, acid intensity, crystal structure and thermal stability of the supported phosphotungstic acid catalyst. With phosphotungstic acid /semi-coke as catalyst, 30%hydrogen peroxide as oxidant and span60 as surfactant, organic sulfur compounds are removed from FCC diesel by a catalytic oxidation method. The effect of reaction temperature, reaction time, the amount of catalyst, the amount of span60 and the amount of hydrogen peroxide on desulfurization are investigated. The quantification of sulfur in the reaction products are conducted by microcoulometry analysis （WD-2K）, the sulfur compounds in the original liquid fuels and the desulfurized are analyzed by GC-950. The oxidative desulfurization of FCC diesel is also explored in the continuous operation conditions. At last, the oxidation process conditions of DBT are optimized, reaction kinetics of oxidation of DBT and FCC diesel are studied.The results of characterization show that the Keggin structure of catalysts remains unchanged, Phosphotungstic acid disperse on the support or into the inner hole in the form of micro-crystalline cluster, the acid strength of catalysts increases a little when the increase of loading, catalysts show good thermal stability. Oxidative desulfurization on the FCC diesel is conducted. The result shows that the order of the influence factors for the sulfur removal efficiency is: the amount of hydrogen peroxide> the amount of HPW/Sc2 > reaction time > reaction temperature> the amount of Span60, the optimum reaction conditions are as follows: reaction temperature at 60℃, reaction time 60min, 1wt% of HPW/Sc2, [H₂O₂]/[S]=3, 0.36wt% of Span60.Sulfur compounds in oxidized FCC diesel are removed by extraction, the NMP of 90%used as extraction agent, the three important factors, extraction time, extraction temperature and the volume ratio of extraction agent to FCC diesel are investigated, the best extraction condition is: the volume ratio of extraction agent to FCC diesel is 1:1, extraction time 10min, extraction temperature 25℃, the sulfur removal efficiency and the yield of the oil are 79.83% and 98.0%, sulfur compounds in oxidized FCC diesel are removed by adsorption, CuO is selected as adsorbent, the sulfur removal efficiency can come up to 86.03%.The result of model compounds experiment indicates that aromatic hydrocarbon, olefins and nitrogen compounds have influence on the removal of model compounds, and the sequence of them influence from big to small is quinoline, cyclohexene, benzene; the oxidation reactivities of model compounds decrease in the order of DBT>4,6-DMDBT>BT. The oxidation reaction of DBT and FCC diesel fits well with pseudo-first-order reaction kinetics.The fresh and regenerated HPW/Sc2 catalyst are characterized by means of SEM, FT-IR and UV-Vis DRS. The results show that FT-IR spectra and UV-Vis DRS spectra of fresh and regenerated catalysts are almost the same, and the catalyst maintains the structure of Keggin. The regenerated catalyst demonstrates the same catalytic activity as the fresh catalyst; the used extractants are recycled by distillation. The sulfur removal efficiency is reduced by 6.5% with recycled NMP.更多还原