二苯并噻吩的加氢脱硫反应研究综述

加氢脱硫是一种比较成熟的生产工艺,已在原油精制中普遍使用了多年.随着原油质量变差和更严格的环境法规的应用(例如,需要降低燃料中的硫含量),人们对该工艺不断更新.在实现燃料低硫水平方面,特别重要的是一类特殊化合物如:二苯并噻吩、4-甲基二苯并噻吩和4,6-二甲基二苯并噻吩所造成的受阻问题.在使用现有催化剂加氢精制时,二苯...     

芬顿试剂光氧化二苯并噻吩的研究

采用UV芬/顿系统应用于光氧化二苯并噻吩(DBT)的研究。结果发现UV/芬顿系统的脱硫效果不错,反应的最优条件:Fe2+质量浓度为12 mg/L,H2O2的体积分数20%,最佳pH为3~5。Fe2+/C2O4体系比Fe2+体系具有更强的催化活性。     

二硫代二乙酸合成方法的改进

不用碘,在彭特盐(NaOOC—CH_2—S·SO_3Na)溶液中滴加硫化铵和盐酸制备二硫代二乙酸.     

NiW/Al2O3催化剂上二苯并噻吩的加氢脱硫宏观动力学

以二苯并噻吩(DBT)为含硫模型化合物,在实验室中压滴流床反应装置中研究了工业NiW/Al2O3催化剂RN-10上的加氢脱硫反应的动力学规律,详细考察了工艺条件:氢分压2.4～4.5 MPa、氢油比150～700(v/v)、液时空速(WHSV)15～60 h-1、反应温度300～380C对DBT转化率的影响.实验结果表明:提高反应温度可大大提高DBT的转化率,但反应温度达到330℃后,再提高反应温度,对DBT转化率的提升有限;在较高氢分压的条件下,DBT的转化率受氢分压的影响很小;当氢油比较小时,随着氢油比的提高,DBT转化率逐渐增加,但当氢油体积比大到一定程度(500)时,继续增大氢油比对脱硫率几乎没有影响.采用修正了的2级反应动力学模型对实验数据进行拟合,求得了二苯并噻吩加氢脱硫反应的表观活化能为75.95 kJ·mol-1.经检验,模型计算结果与实验结果能较好地吻合.     

二苯并噻吩分子印迹复合膜的脱硫

以聚丙烯膜为基膜,经多巴胺氧化和硅烷化处理后,以表面印迹法制备二苯并噻吩分子印迹复合膜.以红外光谱及扫描电镜对复合膜进行结构表征,以静态吸附脱硫实验进行脱硫性能表征,结合自制的吸附-解吸耦合脱硫装置进行实验.红外光谱与扫描电镜显示实验制得的复合膜印迹效果良好.静态吸附结果表明,表面聚合比溶液聚合平衡吸附量增加了66％,...     

柠檬酸促进NiMoP催化剂上二苯并噻吩脱硫反应

车用燃油中的含硫化合物是大气主要污染物SOx的主要来源,降低燃油中该类化合物含量是减少汽车尾气SOx排放量的重要保障。燃油加氢脱硫技术是满足这一环保要求的最重要手段,技术的关键是研制高效加氢脱硫催化剂。通过在NiMoP浸渍液中添加不同含量的柠檬酸,制备一系列NiMoP/Al₂O₃催化剂,以二苯并噻吩为模型化合物,考察催化剂在制备过程中添加柠檬酸对NiMoP/Al₂O₃催化剂加氢脱硫性能的影响。结果表明,柠檬酸的加入能够提高催化剂的加氢脱硫性能,明显改善NiMoP/Al₂O₃催化剂的加氢性能。     

磷化物催化剂体系下二苯并噻吩加氢反应网络研究

为考察二苯并噻吩在磷化物体系下催化加氢的反应网络,以分子筛SBA-15为空白载体,利用等体积浸渍制取了一系列磷化物催化剂,Ni/P摩尔比为1.25,对不同Ni金属担载量的磷化物催化剂的性质进行了分析。采用含有1%二苯并噻吩的模型化合物为原料进行加氢脱硫试验,利用20 m L连续固定床加氢精制装置对制备的磷化物催化剂进行了活性评价。结果表明,相对于商业催化剂,低温和磷化物催化剂体系下二苯并噻吩具有更高的转化率,280℃转化率可达80%以上;碱性氮化物喹啉的存在抑制了二苯并噻吩加氢反应,转化率在320℃时由接近100%降至70%左右,此条件下,产物中联苯以及环己烷基苯的选择性随温度变化不大,二苯并噻吩大部分通过直接脱硫路径进行转化。评价结果显示,磷化物催化剂具有更高的氢解活性和更好的直接加氢脱硫效果。     

二氯二茂锆合成方法的改进

二氯二茂锆是Kaminsky型催化体系的主催化剂,该类催化剂催化烯烃高聚的活性和等规度都很高[1],催化烯烃齐聚亦有文献报道[2,3]。二氯二茂锆也是Negishi试剂的主要组分,该试剂可用于分子内双烯的成环反应和分子间炔烃与烯烃的成环反应[4～6]。Murray报道了二氯二茂锆的合成方法,但产率较低[7];Reid等报道的合成方法虽产率较高但操作复杂,条件苛刻[8～10]。为了简化操作,缩短反应时间,提高产率,本文对合成方法进行了研究和改进。1　实验部分1.1　反应原理Na,THF室温-Na ZrCl4,甲苯室温Cp2ZrCl21.2　主要仪器与试剂XRC-1型显微熔点测定…     

微波辐射下二苯并噻吩的氧化脱除研究

以磷钼酸铬盐为催化剂、过氧化氢为氧化剂,研究了微波辐射加热下模拟汽油中二苯并噻吩的氧化脱除。分别考察了催化剂用量、氧化剂用量、反应温度和反应时间对氧化脱硫的影响。当m（Catalyst）：m（Oil）为7．1mg·g^-1、V（30％H2O2）：V（Oil）为50mL·L^-1、反应温度为80℃、反应时间为50min时、n（磷钼酸）：n（CrCl3）为1：1和1：2,二苯并噻吩脱除率分别达到93．5％和91．2％。     

二苯并噻吩在Ni-Mo-W/γ-Al2O3上加氢脱硫机理的研究

研究了二苯并噻吩(DBT)在Ni-Mo-W/γ/Al2O3上的加氢脱硫(HDS)反应产物分布、可能的反应网络以及温度对产物分布的影响,揭示了HDS反应的可能机理.研究发现,DBT在Ni-Mo-W/γ-Al2O3上的HDS反应主要通过直接氢解路径和加氢路径进行,且后者的速率是前者的两倍.考察了芳烃(萘)、硫化物(硫化氢)和氮化物(喹啉)三种物质对DBT在Ni-Mo-W/γ-Al2O3催化剂上HDS反应的影响,结果表明,芳烃对反应有较弱的抑制作用,并且对两个路径的抑制作用相当.氮化物喹啉对反应有较强的抑制作用,其主要是通过竞争吸附作用抑制加氢路径.硫化物H2S对反应也有一定的抑制作用,其抑制直接氢解脱硫路径,但对加氢路径有一定的促进作用.     

A key intermediate in the platinum-mediated hydrodesulfurization of dibenzothiophene

The thiaplatinacycles, [PtL2(C,S–C₁₂ H₈S)] and [PtL₂(C,S–C₁₃H10S)] (L = PEt₃, PMe₃; L₂=Ph₂PCH₂ CH2PPh₂), obtained from oxidative insertion of [Pt⁰Ln] into dibenzothiophene and 4-methyldibenzothiophene are hydrodesulfurized by reaction with hydrogen (toluene, 20 atm, 100°C) to biphenyl and 3-methylbiphenyl, respectively; addition of acidic alumina improves the reaction. These observations link the model systems and the latest generation of commercial second-stage HDS catalysts. This revised version was published online in July 2006 with corrections to the Cover Date.     

含硅烃基氯化锡的合成及其结构表征

用四（烃硅基亚甲基）锡和四氯化锡按不同的物质的量比进行反应,合成了相应的三烃基一氯化锡、二烃基二氯化锡和一烃基三氯化锡。讨论了影响反应的主要因素,并使用高效液相色谱对反应的进程进行跟踪检测。通过^1HNMR和元素分析,确定了这些化合物的结构。生物活性试验的初步结果显示,含硅二烃基二氯化锡对肺癌细胞SPC-A-1具有较好的体外抗癌活性。     

碳酸甲苯酯的合成及光谱研究

通过苯酚和碳酸二甲酯的酯交换反应合成了碳酸甲苯酯,采用减压精馏对其进行了分离提纯,得到纯度>99.5%的碳酸甲苯酯;运用红外光谱、紫外光谱、核磁共振氢谱以及质谱对其结构进行了表征,并对其光谱数据进行了解析。     

Hydrodesulfurization of dibenzothiophene on alumina-supported molybdenum nitride

An alumina-supported molybdenum nitrided catalyst was prepared and tested to determine its activity and selectivity during the hydrodesulfurization of dibenzothiophene. The nitrided catalyst was extremely active for the selective C-S bond breakage of dibenzothiophene to produce biphenyl.     

钛硅分子筛光催化氧化二苯并噻吩的研究

采用液固相同晶取代法和微波法合成了Ti-β,Ti-NaY和Ti-MCM-41a,并通过红外和紫外-可见漫射对样品进行表征。以二苯并噻吩为研究对象,考察了钛硅分子筛的光催化活性。结果发现,钛硅分子筛具有很好的光催化性能,光催化氧化脱硫的活性顺序为:Ti-MCM-41a>TS-1>Ti-NaY>Ti-β。10 mL模型油为基准的最佳反应条件为:钛质量分数,Ti-β为0.37%,Ti-NaY为3.7%和Ti-MCM-41a为5.325%;催化剂用量,Ti-NaY为0.05 g,Ti-β为0.05g,Ti-MCM-41a为0.04 g,H2O2用量(氧硫摩尔比):Ti-NaY为5.33∶1,Ti-β和Ti-MCM-41为12.39∶1。     

Effect of supercritical deposition synthesis on dibenzothiophene hydrodesulfurization over NiMo/Al2O3 nanocatalyst

The synthesis of two NiMo/Al₂O₃ catalysts by the supercritical carbon dioxide/methanol deposition (NiMo‐SCF) and the conventional method of wet coimpregnation (NiMo‐IMP) were conducted. The results of the physical and chemical characterization techniques (adsorption–desorption of nitrogen, oxygen chemisorption, XRD, TPR, TEM, and EDAX) for the NiMo‐SCF and NiMo‐IMP demonstrated high and uniform dispersed deposition of Ni and Mo on the Al₂O₃ support for the newly developed catalyst. The hydrodesulfurization (HDS) of fuel model compound, dibenzothiophene, was used in the evaluation of the NiMo‐SCF catalyst vs. the commercial catalyst (NiMo‐COM). Higher conversion for the NiMo‐SCF catalyst was obtained. The kinetic analysis of the reaction data was carried out to calculate the reaction rate constant of the synthesized and commercial catalysts in the temperature rang of 543–603 K. Analysis of the experimental data using Arrhenius' law resulted in the calculation of frequency factor and activation energy of the HDS for the two catalysts. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

青藤碱与羟丙基-β-环糊精的包合作用研究

通过溶液共混法制备青藤碱-羟丙基-β-环糊精包合物,纯化后利用体视显微镜观察包合物的结晶形态,通过差热示重扫描、红外光谱、X射线粉末衍射及核磁共振等方式对包合物进行性质分析,并通过相溶解度法计算包合物的包合常数。结果表明青藤碱-羟丙基-β-环糊精包合物性质发生明显变化,羟丙基-β-环糊精能显著增加青藤碱的溶解度,青藤碱-羟丙基-β-环糊精包合物是一种稳定的新物质,青藤碱与HP-β-CD形成的包合物的包合分子比为1∶1,其包合常数为150.0。     

Biodesulfurization of dibenzothiophene using recombinant Pseudomonas strain

BACKGROUND: The sulfur content in crude oil available from various sources ranges from 0.03 to values as high as 8.0 wt%. These high quantities of sulfur must be removed before the crude oil is processed because combustion of this oil would result in severe environmental pollution, such as acid rain. Due to high utility and operating costs, the conventional hydrodesulfurization process (HDS) is considered to be uneconomic. The biotechnological option, biodesulfurization (BDS) seems an attractive low cost, environmentally benign technology. RESULTS: This paper reports the development of a recombinant strain of bacteria designed by introducing desulfurizing, dsz genes containing plasmid pSAD 225‐32, which was isolated from Rhodococcus erythropolis IGTS8 into a gram negative solvent‐tolerant bacterium, Pseudomonas putida (MTCC 1194). This recombinant bacterium can desulfurize the dibenzothiophene (DBT) in the sulfur selective 4S‐pathway. It has been observed that for the same concentration of DBT, the recombinant strain's growth rate is greater than that of the parent strain. Increasing the concentration of DBT resulted in an increase of lag phase as well as decreased growth rate, which shows that the bacteria is following substrate inhibition type kinetics. This genetically modified bacterium can desulfurize 73.1% of 1.2 mmol L^?1 DBT (dissolved in ethanol) in 67 h of cultivation time using growing cells. CONCLUSIONS: It is concluded that further research in this area of biodesulfurization using genetically modified organisms may remove the bottlenecks presently in the way of commercialization of the BDS process. Copyright © 2007 Society of Chemical Industry     

青藤碱与羟丙基-β-环糊精的包合作用

通过溶液共混法制备青藤碱-羟丙基-β-环糊精包合物,纯化后利用体视显微镜观察包合物的结晶形态,通过差热示重扫描、红外光谱、X射线粉末衍射及核磁共振波谱等方法对包合物进行性质分析,并通过相溶解度法计算包合物的包合常数。结果表明,青藤碱、羟丙基-β-环糊精包合后性质发生明显变化,羟丙基-β-环糊精能显著增加青藤碱的溶解度,包合物中青藤碱与羟丙基-β-环糊精包合分子个数比为1∶1,其包合常数为150.0 L/mol,反应的吉布斯自由能为-12.41 kJ/mol。     

Effect of plasticizers in poly(vinyl alcohol)‐based hybrid solid polymer electrolytes

Hybrid solid polymer electrolyte films consisting of poly(vinyl alcohol) (PVA), poly(methyl methacrylate) (PMMA), LiBF₄, and ethylene carbonate/propylene carbonate (EC/PC) were prepared with a solvent‐casting technique. The complexation was investigated with Fourier transform infrared and X‐ray diffraction. The ionic conductivities of the electrolyte films were determined with an alternating‐current impedance technique for various temperatures in the range of 302–373 K. The maximum conductivity value, 1.2886 × 10^?3 S/cm, was observed for a PVA–PMMA–LiBF₄–EC complex. Thermogravimetry/differential thermal analysis was performed to ascertain the thermal stability of the electrolyte with the maximum conductivity value. For an examination of the cyclic and reversible performance of the film, a cyclic voltammetry study was carried out. The surface morphology of the EC‐and PC‐based electrolytes was examined with scanning electron microscopy. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2794–2800, 2003