【作者】 丁保宏；

【导师】 臧树良； 何品刚；

【作者基本信息】 华东师范大学 ， 分析化学， 2011， 博士

【摘要】 随着日益严格环保法规的不断出台和原油重质化、劣质化趋势的不断扩大,燃料油中硫、氮以及芳烃的脱除成为一个亟待解决的重要问题。生产低硫含量、低芳烃特别是多环芳烃含量、高十六烷值和低密度的清洁柴油成为提高柴油质量的方向,对我国柴油质量的提高将会具有极为重要的现实意义。因此迫切需要研制具有高效加氢脱硫、加氢脱氮以及加氢脱芳烃的催化剂来满足油品深度加氢处理的需求。近年来对高效深度加氢精制催化剂的研究开发主要集中在寻找活性更高的组分和更优良的载体。复合氧化物载体不仅可以把不同氧化物的优势互补,方便地调变载体性质,还可能产生单一氧化物不具备的新性质,成为国内外学者关注的热点。本论文首次分别采用共沉淀法和溶胶凝胶法制备了SiO2-TiO2-ZrO2复合氧化物载体。采用共浸渍法将活性组分Mo、P负载在SiO2-TiO2-ZrO2载体上,合成了负载型MOP/SiO2-TiO2-ZrO2催化剂。采用X射线衍射、N2物理吸附、吡啶吸附红外光谱、扫描电镜等技术对其进行了表征；以噻吩、萘和喹啉为模型化合物,在小型固定床反应器上考察了催化剂的加氢脱硫、加氢脱芳和加氢脱氮性能；研究了复合氧化物中原料配比以及焙烧条件等对SiO2-TiO2-ZrO2复合氧化物结构的影响。探索以不同Si/Ti/Zr原子比的SiO2-TiO2-ZrO2复合氧化物为载体制备的催化剂在柴油加氢精制中应用的可行性,为开发具有较高活性和选择性的载体以及催化剂提供了科学依据。主要研究结果如下：1.共沉淀法制备三元复合氧化物SiO2-TiO2-ZrO2(Sx)把配方均匀设计应用到催化剂载体的原料比考察中,全面考察了Si. Ti、Zr原子比对载体性质以及催化剂活性的影响,成功制备了介孔SiO2-TiO2-ZrO2三元复合氧化物。该复合氧化物为介孔材料,颗粒直径约60 nm,其表面结构和孔结构较单一载体以及二元复合载体有一定程度的提高。当焙烧温度为500℃, n(Si)/n(Ti)/n(Zr)=0.163/0.809/0.028时,载体的晶体结构最为明显,表面结构最优,S11比表面积可达384.47m2/g,孔容0.72 cm3/g,孔径26.2 nm,是典型大比表面积的介孔材料。载体具有良好的晶相稳定性和热稳定性。Si、Ti、Zr原子比对复合氧化物的表面结构有较大影响,可以根据需要通过调节Si、Ti、Zr的原子比来调控复合氧化物的表面性质。2.溶胶凝胶法制备三元复合氧化物SiO2-TiO2-ZrO2(S15-x)SiO2-TiO2-ZrO2三元复合氧化物颗粒的形貌呈四边或五边形,颗粒直径约50 nm,其表面结构和孔结构较单一载体以及二元复合载体有一定程度的提高。Si、Ti、Zr原子比对复合氧化物的表面结构有较大影响,因此可以根据需要通过调节Si、Ti、Zr原子比来调控复合氧化物的表面性质。当焙烧温度为500℃、n(Si)/n(Ti)/n(Zr)=0.163/0.809/0.028时,载体S15-11的比表面积可达315 m2/g,孔容0.33cm3/g,孔径12.0nm,是典型大比表面积的介孔材料。该复合氧化物具有良好的晶相稳定性和热稳定性。3. MoP/SiO2-TiO2-ZrO2催化剂(Cx和C15-x)的制备与表征MoP/SiO2-TiO2-ZrO2催化剂的活性组分与载体间存在着适宜的相互作用,活性组分在载体上完全均匀分散。SiO2-TiO2-ZrO2载体负载活性组分后,表面性质变化较大,比表面积和孔容较大幅度下降,但孔径有所增加；催化剂C15-X比表面积比催化剂Cx比表面积下降的幅度更快。催化剂MoP/SiO2-TiO2-ZrO2据有相对良好的表面性质：C11的比表面积为291m2/g、孔容0.65cm3/g、孔径28.4nm；C15-11的比表面积为175m2/g、孔容0.21cm3/g、孔径15.6nm；800℃下焙烧后,催化剂MoP/Si02-TiO2-ZrO2的晶体结构无明显差异,具有良好的热稳定性；催化剂MoP/SiO2-TiO2-ZrO2的比表面积和孔容均随焙烧温度的升高而降低,但是在700℃仍然能维持较大的比表面积和孔容,说明催化剂的结构热稳定性良好。4.MoP/SiO2-TiO2-ZrO2催化剂的活性评价Si、Ti、Zr原子比对MoP/SiO2-TiO2一ZrO2催化剂的加氢精制活性影响较大。但由于载体中三种组分之间相互作用的复杂性,这种影响的趋势不够明显,各组分可以根据需要在一定范围内调变组成,得到加氢活性良好的催化剂。共沉淀和溶胶凝胶两种方法制备的SiO2-TiO2一Zr02复合氧化物都是新型加氢精制催化剂的优良载体。11号配比的催化剂加氢精制活性最为理想：C11的HDS达99.8%、HAD为78.2%、HDN为91.7%；C15-11的HDS为99.6%,HDA为80.0%,HDN可达92.5%。在试验条件下催化剂C11的HDS最佳99.8%；C5的HDA最佳达到82.9%；C2的HDN最佳达92.8%。三元载体SiO2-TiO2-ZrO2应用于加氢精制催化剂后具有比二元载体TiO2-SiO2、TiO2-ZrO2、TiO2-Al2O3更加优良的活性,C11的HDS率提高11～27%、HDN率提高6-16%、HDA率提高2-18%；C15-11的HDS率提高13～25%、HDN率提高11～19%、HDA率提高9～20%。催化剂的最佳活性组分负载量为20%。对C11、C15-11进行了1200小时长周期稳定性实验,加氢脱硫活性一直保持稳定,说明两种方法制备的催化剂稳定性良好、寿命较长。用C11、C15-11处理实际油品,结果表明两种催化剂都具有具有良好的柴油加氢精制性能：HDS基本都在96%以上；HAD基本在65%以上；HDN都在85%以上；十六烷值提高12～17个单位。说明两种催化剂具有良好的工业应用前景。5.MoP/SiO2-TiO2-ZrO2催化剂的原位还原及加氢工艺条件MoP/SiO2-TiO2-ZrO2催化剂的最佳原位还原条件：还原气压力1.0MPa；还原气流量100.0mL/min;升温速率小于5℃/min;还原终温600℃。通过单条件实验得到MoP/SiO2-TiO2-ZrO2催化剂加氢脱芳的最佳工艺条件为：反应温度为340℃、空速为2h-1、反应压力4.0Mpa、氢油比500。通过正交试验确定MoP/SiO2-TiO2-ZrO2催化剂加氢脱硫最佳工艺条件为：反应温度380℃,空速2h-1,氢油体积比500,氢分压4 MPa。各因素对催化活性的影响顺序为：反应温度>氢分压>体积空速>氢油体积比。更多还原

【Abstract】 In view of more stringent environmental legislations and expanding continue of crude oil and heavy qualitative inferior trend in the fuel oils, sulfur, nitrogen and aromatic’s removal from oil have becoming an important problem to be resolved. It has become direction of raiseig the diesel production low sulfur, low aromatics especially polyaromatic hydrocarbon, high hexadecane value and low density clean diesel quality. It will have important practical significance to improve the quality of our diesel.It is very urgently to develop efficient refine catalysts to meet aromatic oil depth hydrotreating requirements.In recent years the research and development of depth efficient catalyst hydrotreating mainly focus on the components and active higher more excellent carrier.Composite oxide has become the focus in domestic and foreign scholars,it can not only the carrier of complementary advantages of different oxide and modulation carrier properties easily, but also produce a new properties single oxide doesn’t have.In the thesis, The composite oxide support of SiO2-TiO2-ZrO2 was prepared by coprecipitation method and sol-gel method for the first time.Active components MoP were co-impregnated on the support to form MoP/SiO2-TiO2-ZrO2 catalyst. And then characterized by XRD, nitrogen absorption, infrared spectroscopy of absorbed pyridine and scanning electron microscope; In a fixed bed reactor,The hydrofining activities of the catalysts were tested on a model compound of thiophene, naphthalene and quinoline; The influence of raw material’s ratio and baking conditions on the structure of the SiO2-TiO2-ZrO2 composite oxid were examined.The feasibility of the composite oxide as the support of diesel hydrofining catalyst was examined.The main research results are as follows:1. Ternary composite oxide of SiO2-TiO2-ZrO2 (Sx) prepared by coprecipitation methodTernary composite carrier of SiO2-TiO2-ZrO2 was prepared by coprecipitation method successfully. the recipe uniform design was applicated in investigation of Carrier’s raw material ratios.The composite oxide is mesoporous material, particle diameter is about 60 nm.Compared with single and binary composite oxide,SiO2-TiO2-ZrO2 composite oxide’s specific surface area, the thermal stability and crystal stability are obviously improved.When roasting temperature is 500℃and the nsi/nTi/nzr ratio is equal to 0.163/0.809/0.028, the crystal structure is most obvious and the surface structure is optimal,the specific surface can get 384.47 m2/g,pore volume is 0.72 cm3/g and the aperture is 26.2nm; It is typical mesoporous materials with large specific surface. Carrier has good crystalling phase stability and thermal stability.Si/Ti/Zr atomic ratio of composite oxide has great influence on the surface structure,the Surface properties of composite oxide can be controlled by adjusting the Si, Ti, Zr atomic ratios.2. The SiO2-TiO2-ZrO2 ternary composite oxide(S15-x) prepared by sol-gel methodThe SiO2-TiO2-ZrO2 ternary composite oxide is quadrilateral or pentagons, particle diameter is about 50 nm.Compared with single and binary composite oxide,SiO2-TiO2-ZrO2 composite oxide’s specific surface area, the thermal stability and crystal stability are obviously improved.Si/Ti/Zr atomic ratio of composite oxide has great influence on the surface structure,the Surface properties of composite oxide can be controlled by adjusting the Si/Ti/Zr atomic ratios.When roasting temperature is 500℃, nsi/nTi/nzr atoms ratio is equal to 0.163/0.809/0.028,the specific surface is 315 m2/g,pore volume is 0.33 cm3/g and the aperture is 12.0nm; It is typical mesoporous materials with large specific surface.The composite oxide has good crystalling phase stability and thermal stability.3. Preparation and Characterization of MoP/SiO2-TiO2-ZrO2 Catalyst (Cx and C15-x)There exists Appropriate interactions between the active components and carrier,and the active component equably dispersed totally on the carrier.SiO2-TiO2-ZrO2’surface properties have taken place great changes after loading active components,the specific surface area and pore volume dropped greatly, but aperture increase.The specific surface area of C15-x dropped more faster than Cx.Catalyst MoP/SiO2-TiO2-ZrO2 has good surface properties relatively:C11’s specific surface is 291 m2/g,pore volume is 0.65 cm3/g and the aperture is 28.4 nm; C15-11’s specific surface is 175 m2/g,pore volume is 0.21 cm3/g and the aperture is 15.6nm;The crystal structure of the catalyst MoP/SiO2-TiO2-ZrO2 have no significant difference after roasted on 800℃,this indicate that the catalyst has thermal stability.The MoP/SiO2-TiO2-ZrO’s specific surface area and pore volume decline with the raising temperature.But it can remain large specific surface area and catalyst structure under the 700℃,this indecate that the catalyst has good thermal stability.4.Evaluation activity of catalysts MoP/SiO2-TiO2-ZrO2The effect of Si/Ti/Zr atomic ratio on hydrofining performance is big.But because the complexity of the interaction between the trend of this kind of influence, the effect isn’t absolutely,each component can not absolutely according to need within the scope of certain and modulation components, get catalysts hydrogenation with good activity.SiO2-TiO2-ZrO2 composite oxides prepared by coprecipitation and sol-gel method are all excellent carrier of novel Hyrorefining catalyst.C11 has the best hydrotreating activity:HDS is 99.8%、HDA is 78.2 %、HDN is 91.7%;To C15-11:HDS is 99.6%、HDA is 80.0%、HDN is 92.5 %; Under the experimental conditions,Catalyst C11’HDS can reach 99.8%,C5 has the best HAD,82.9%;C2 has the best HDN,93.8%.Ternary carrier SiO2-TiO2-ZrO2 has more excellent activity than binary carrier in hydrotreating.The best active component load is 20%.Long cycle stability tests have been done on C11 and C15-11 for 1200 hours, hydrodesulfurization performance are stability,it indicated that two kinds of catalysts are stability and long service life.Processing actual oil with C11 and C15-11,two kinds of catalysts show good diesel hydrotreating performance,HDS is above 96%,HAD is above 65%,and HDN is above 85%. Hexadecane value increase 12-17 units. This means that two catalysts possess good industrial application foreground.5. In situ reduction and hydrogenation process conditions of MoP/SiO2-TiO2-ZrO2 catalystTo MoP/SiO2-TiO2-ZrO2 catalyst,the favorable conditions of the in situ reduction are as follows:total pressure 1.0 MPa、H2 flow rate 100.0 ml/min, heating rate≤5℃/min, and reduction temperature 600℃.The favorable conditions of the HDA were getten through single condition experiments:reaction temperature is 340℃, airspeed is 2 h-1, reaction pressure is 4.0 Mp, oil-hydrogen ratio is 500. The favorable conditions of the HDS were getten Through an orthogonal test:reaction temperature is 380℃, airspeed is 2h-1, reaction pressure is 4.OMp and oil-hydrogen ratio is 500.The influence order of each factor to the catalytic activity:reaction temperature>reaction pressure>airspeed>oil-hydrogen ratio.更多还原