Deep desulfurization of diesel by selective oxidation using amphiphilic paradodecatungstate catalyst

An amphiphilic paradodecatungstate catalyst, [(C₁₈H₃₇)₂N(CH₃)₂]₉[NaH₂W₁₂O₄₂] was prepared and characterized by Fourier transform infrared spectroscopy, UV–visible spectrum, differential thermal analysis, and thermogravimetric analysis. The amphiphilic catalyst exhibits very high catalytic activity that dibenzothiophene (DBT) in model diesel can be oxidized into dibenzothiophene sulfones using hydrogen peroxide as an oxidant. The reactivity of sulfur compounds decreased in the order of DBT > 4,6-DMDBT > BT > 5-MBT. The reaction rates of these sulfur compounds are sensitive to the electron density on sulfur atoms and the steric hindrance of the substituted groups of sulfur compounds. The sulfur level of a commercial diesel after desulfurization can drop from 200 ppm to about 12 ppm.     

相转移催化剂对催化柴油氧化脱硫作用的数学模型

经过顺序氧化反应动力学方程、相转移催化剂强化作用数学模型方程和萃取相平衡方程的推导,确定了催化柴油氧化萃取脱硫数学模型方程。研究表明,呈指数函数形式的相转移催化剂作用数学模型具有较高的计算精度。通过模型参数估值确定了氧化速率常数的频率因子和活化能、相平衡常数、相转移催化剂作用模型参数,建立了脱硫率数学模型。模型预测显示,柴油脱硫率随着氧化时间延长呈先提高后降低的趋势;氧化时间较短时,柴油脱硫率随相转移催化剂用量提高而增大,但氧化时间较长时的情况相反;柴油脱硫率随着氧化溶液体积分数增大或萃取剂与油比增大均呈提高的趋势。     

Ti-MWW分子筛催化叔丁基过氧化氢氧化脱硫

以Ti-MWW为催化剂,考察了不同氧化剂对分别含有苯并噻吩、二苯并噻吩和4,6-二甲基二苯并噻吩等有机硫化物模拟油品氧化反应的影响,结果表明,叔丁基过氧化氢对有机含硫化合物的氧化活性明显高于过氧化氢水溶液。以叔丁基过氧化氢为氧化剂,三种噻吩类含硫化合物氧化的难易顺序为二苯并噻吩> 4, 6-二甲基二苯并噻吩> 苯并噻吩,其氧化活性顺序与含硫化合物中硫原子的电子云密度和空间位阻有关。考察了Ti-MWW/叔丁基过氧化氢催化氧化体系对成品柴油的催化氧化脱硫,结果表明,成品柴油中的含硫化合物可被有效地氧化脱除,在优化的反应条件下,经过两次氧化、萃取后,成品柴油中的总硫含量从1015μg/mL降低至11μg/mL,总脱硫率达到99%。     

功能化酸性离子液体催化柴油氧化脱硫的研究

以功能化酸性离子液体为催化剂,30%双氧水为氧化剂,将加氢柴油中的含硫化合物氧化为相应的砜类物质,并用N-甲基吡咯烷酮（NMP）萃取一次。同时考察了反应温度、反应时间和催化剂用量等因素对氧化脱硫反应的影响,得出最佳反应条件为,3mL油样（硫的质量分数为200×10-6）、1.5g酸性离子液体、 0.3mL H2O2、 25℃,3.5h、VNMP/Vdiesel=1∶1,脱硫率可达到86.7%,柴油硫的质量分数仅为25×10-6左右,反应结束后,可通过简单的倾倒将油样和催化剂分离,重复使用5次,其催化活性变化不大。     

Adsorptive desulfurization of diesel with mesoporous aluminosilicates

Mesoporous aluminosilicates (MAS) bearing microporous zeolite units and mesoporous structures were synthesized by the hydrothermal method. Adsorptive desulfurization ability of model oil and hydrotreated diesel was studied. The effects of template concentration, crystalization time and calcination time were investigated. The desulfurization ability of adsorbents was improved by transitional metal ion-exchanging. The adsorptive desulfurization of diesel was carried out on a fixed-bed system. The results show that the adsorptive capacity is MAS>MCM-41>NaY. The improvement of desulfurization ability of MAS by Cu⁺ is more significant than that of Ag⁺. Supported by National Basic Research Program of China (Grant No. 2006CB202507), National High-tech R&D Program (Grant No. 2006AA02Z209), and the National Natural Science Foundation of China (Grant No. 20806086)     

银离子修饰的介孔磷钨酸/二氧化硅催化剂氧化脱硫性能研究(英文)

采用银修饰介孔磷钨酸/二氧化硅(mesoporous HPW/SiO2)催化剂,并研究了其在模拟柴油和真实柴油氧化脱硫反应中的催化性能.通过银修饰介孔HPW/SiO2,结合银离子对有机硫化物的选择吸附性和HPW对有机硫化物的催化氧化活性,以达到选择氧化脱硫的目的.模拟柴油分别采用石油醚、苯、1-辛烯和二苯并噻吩配制,当银离子与HPW的摩尔比为2时,催化剂具有最高的选择催化氧化活性.采用N2 吸附-脱附、XRD、UV-vis和EDS表征了银修饰的介孔HPW/SiO2催化剂,结果表明,银物种分散均匀且以Ag+形式存在.真实柴油的脱硫研究表明,相比介孔HPW/SiO2催化剂,修饰的催化剂介孔Ag2-HPW/SiO2脱硫率提高了4.6%,初始硫含量为1800×10-6的直馏柴油能被脱除至228×10-6,脱硫率为87.3%.介孔Ag2-HPW/SiO2催化剂具有良好的再生性能,经再生处理后,Ag的损失量极少,其三次脱硫率达到84.8%.     

乳液催化剂存在下空气辅助甲酸氧化法使油品脱硫(英文)

Catalytic oxidative desulfurization(ODS) of model oil and commercial oil samples was investigated using an air-assisted performic acid oxidation system with a phase transfer or emulsion catalyst comprising a quaternary ammonium salt-based heteropolyoxometalate.Different emulsion catalysts with a Keggin type heteroployoxometalate anion(containing W,Mo,and V) and cetyltrimethylammonium bromide cation were prepared and characterized by X-ray fluorescence,Fourier transform infrared spectroscopy,and scanning electron microscopy.[C16H33N(CH3)3]3[PW9Mo3O40] was the most effective catalyst in the current oxidation system,which reduced the sulfur content of the model oil from 1275 μg/g to 57 μg/g.The reactivity order of different model sulfur compounds was thiophene < dibenzothiophene < 4,6-dimethyldibenzothiophene. The ODS of model sulfur compounds followed first order kinetics with apparent activation energy from 29 to 27 kJ/mol.The catalysts also performed efficiently in the ODS of the industrial oil samples,including untreated naphtha,light gas oil,heavy gas oil,and Athabasca oil sands derived bitumen,for which sulfur removal rates were 83%,85%,68% and 64%,respectively.     

柴油在超声波/Cu2+/H2O2中的氧化脱硫

为了实现生产低硫柴油和超低硫柴油的目标,以超声波为外加能源,构筑超声波/类Fenton试剂的柴油氧化脱硫反应体系,考察了水相pH值和超声功率这两个参数对柴油氧化脱硫效果的影响。实验结果表明,当类Fenton试剂的水相pH值为2.00左右时,其脱硫效果较好;无超声波下H2O2、类Fenton试剂、超声波/H2O2及超声波/类Fenton试剂的柴油氧化脱硫反应符合表观一级反应动力学规律。超声波功率的提高对氧化脱硫有明显的促进作用,这主要是由于功率的增加,有助于加速空穴的形成与内爆,从而促进反应的进行。     

Selective oxidation of sulfurs and oxidation desulfurization of model oil by 12-tungstophosphoric acid on cobalt-ferrite nanoparticles as magnetically recoverable catalyst

Silica-coated CoFe2O4 nanoparticles were prepared and used as a support for the immobilization of 12-tungstophosphoric acid, to produce a new magnetically separable catalyst. This catalyst was characterized using X-ray diffraction, wavelength-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, laser par-ticle size analysis, and vibrating sample magnetometry. The catalyst showed high activity in the selective oxidation of thioethers and thiophenes to the corresponding sulfones under mild condi-tions. The catalytic activity of the nanocatalyst in the oxidative desulfurization of model oil was investigated. The effect of nitrogen-containing compounds on sulfur removal from the model oil was also evaluated. The catalyst showed high activity in the oxidative desulfurization of diesel. The cata-lyst can be readily isolated from the oxidation system using an external magnet and no obvious loss of activity was observed when the catalyst was reused in four consecutive runs.     

柴油催化氧化脱硫新技术

柴油催化氧化脱硫技术不需高温高压、不耗费氢气、设备投资少等优点,是一项很有前景的脱硫技术。本文介绍了柴油氧化脱硫的机理,重点概述了近年来国内外柴油催化氧化脱硫技术所取的最新成果,并分析了各种氧化脱硫体系的最佳工艺条件和各自的优缺点。     

超声强化过氧化氢/三氯乙酸催化氧化柴油深度脱硫研究

选择H₂O₂一三氯乙酸作为催化氧化脱硫反应体系,砜类氧化产物用极性溶剂从柴油中萃取分离,研究了剂油体积比、有机酸用量、氧化反应温度、氧化反应时间等工艺参数对脱硫率的影响。在此基础上,引入功率超声为反应提供能量,并考察了超声频率、超声功率、超声时间等因素对脱硫效果的影响,从而确定最佳操作条件为,反应温度70℃,反应时间60min,三氯乙酸与过氧化氢体积比为1∶1,氧化剂与柴油体积比为1∶10,超声频率40kHz,超声功率200W,超声时间30min。萃取后柴油脱硫率可达97.5%,脱硫油收率94.0%。     

介孔硅胶在柴油氧化-吸附组合脱硫中的应用研究

以硅胶(SG)为吸附剂,采用自制的双亲催化剂与H₂O₂组成的催化氧化体系将柴油进行氧化,利用固定床动态吸附法考察了硅胶性质、氧化过程及吸附条件等对硅胶吸附脱硫性能的影响,并对硅胶进行了表征。小角XRD和氮气吸脱附结果表明,实验所用硅胶具有介孔结构。吸附脱硫实验结果表明,在油剂比(柴油与吸附剂的体积比)相同时,氧化-吸附脱硫过程脱硫率明显高于吸附脱硫过程脱硫率;选用硅胶作吸附剂,吸附温度为40℃,吸附空速为6.0 h^-1时脱硫效果较好,当油剂比为1时,脱硫率高达94.57%,且该介孔硅胶具有较大的吸附硫容,随油剂比增大下降缓慢,当油剂比增大到15时,脱硫率仍达85.89%。     

银离子修饰的介孔磷钨酸/二氧化硅催化剂氧化脱硫性能研究

采用银修饰介孔磷钨酸/二氧化硅（mesoporous HPW/SiO₂）催化剂,并研究了其在模拟柴油和真实柴油氧化脱硫反应中的催化性能。通过银修饰介孔HPW/SiO₂,结合银离子对有机硫化物的选择吸附性和HPW对有机硫化物的催化氧化活性,以达到选择氧化脱硫的目的。模拟柴油分别采用石油醚、苯、1-辛烯和二苯并噻吩配制,当银离子与HPW的摩尔比为2时,催化剂具有最高的选择催化氧化活性。采用N₂ 吸附-脱附、XRD、UV-vis和EDS表征了银修饰的介孔HPW/SiO₂催化剂,结果表明,银物种分散均匀且以Ag⁺形式存在。真实柴油的脱硫研究表明,相比介孔HPW/SiO₂催化剂,修饰的催化剂介孔Ag₂-HPW/SiO₂脱硫率提高了4.6%,初始硫含量为1800×10^-6的直馏柴油能被脱除至228×10^-6,脱硫率为87.3%。介孔Ag₂-HPW/SiO₂催化剂具有良好的再生性能,经再生处理后,Ag的损失量极少,其三次脱硫率达到84.8%。     

车用燃料油氧化脱硫技术进展

概述了应用于车用燃料油的多种脱硫技术,主要包括加氢脱硫、催化裂化脱硫、吸附脱硫、萃取脱硫、生物脱硫等,并详细介绍了氧化脱硫技术及其脱硫机理。氧化脱硫技术主要包括：含硫化合物的氧化和分离两个步骤,从原子结构上来看,硫原子比碳原子多5个3d轨道,使得含硫化合物更容易接受氧原子而被氧化,通过氧化剂将有机硫化合物氧化成砜类,就能增加其极性,使其更容易溶于极性溶剂,从而达到与烃类分离的目的。与其他脱硫技术相比氧化脱硫技术的投资少,操作条件温和且不消耗氢气,对加氢脱硫难以脱除的二苯并噻吩(DBT)类化合物有较高的脱硫效率,能达到超深度脱硫的要求。     

CuWO4/SBA-15催化剂的制备及其光催化氧化脱硫性能

以CuWO_4为活性组分、SBA-15介孔分子筛为载体,制备CuWO_4/SBA-15催化剂,利用XRD、N_2吸附-脱附、FT-IR、UV-vis、SEM、EDS和TEM对催化剂进行表征分析;以二苯并噻吩(DBT)的十二烷溶液为模拟油,研究了CuWO_4/SBA-15的光催化氧化脱硫(PODS)性能。结果表明,CuWO_4/SBA-15保持了载体高度有序的二维六方介孔结构,活性组分分布均匀,且随负载量增加,其比表面积、孔径和孔容依次减小。与CuWO_4相比,CuWO_4/SBA-15的UV-vis吸收边界蓝移,禁带宽度增加。以二苯并噻吩(DBT)的十二烷溶液为模拟油,评价催化剂的光催化氧化脱硫(PODS)性能。当CuWO_4与SiO_2质量比为0.07,催化剂用量为3%,O/S物质的量比为10∶1,剂油体积比为1∶1,光照反应100 min时,催化剂脱硫率最高,可达到81.5%,明显高于CuWO_4,催化剂重复使用六次后,活性没有明显下降。在PODS反应过程中,·OH和h~+是反应的主要活性物种。     

TEMPO/HCl/NaNO2 catalyst: a transition-metal-free approach to efficient aerobic oxidation of alcohols to aldehydes and ketones under mild conditions

Hydrochloric acid, a very inexpensive and readily available inorganic acid, has been found to cooperate exquisitely with NaNO(2)/TEMPO in catalyzing the molecular-oxygen-driven oxidation of a broad range of alcohol substrates to the corresponding aldehydes and ketones. This transition-metal-free catalytic oxidative conversion is novel and represents an interesting alternative route to the corresponding carbonyl compounds to the metal-catalyzed aerobic oxidation of alcohols. The reaction is highly selective with respect to the desired product when carried out at room temperature in air at atmospheric pressure. Notably, the use of very inexpensive NaNO(2) and HCl in combination with TEMPO for this highly selective aerobic oxidation of alcohols in air at ambient temperature makes the reaction operationally and economically very attractive. The results of mechanistic studies, performed with the aid of electrospray ionization mass spectrometry (ESI-MS), are presented and discussed. TEMPO, TEMPOH, and TEMPO(+) were observed in the redox cycle by means of ESI-MS. On the basis of these observations, a mechanism is proposed that may provide an insight into the newly developed aerobic alcohol oxidation.     

Deep desulfurization by oxidation using an active ionic liquid‐supported Zr metal–organic framework as catalyst

In this study, a Zr metal–organic framework (UIO‐66) was synthesized with zirconium tetrachloride and terephthalic acid using the solvent method. Then various masses of 1‐methylimidazolium‐3‐propylsulfonate hydrosulfate (PSMIMHSO₄) were supported on the UIO‐66 as catalysts, which were used for catalytic oxidative desulfurization. Sulfur removal using 400 mg of 40% PSMIMHSO₄ supported on the UIO‐66 of greater than 94% was obtained at 313 K for 20 min with an O/S molar ratio of 7:1. The results obtained in this work could provide useful information for the design of water‐stable metal–organic frameworks with permanent porosity in applications of catalytic oxidative desulfurization. Copyright © 2014 John Wiley & Sons, Ltd.     

Temperature responsive polymer-supported TEMPO: An efficient and recoverable catalyst for the selective oxidation of alcohols

This study aimed to combine the advantages of homogeneous catalysis and heterogeneous catalysis by immobilizing TEMPO into a water-soluble temperature responsive polymer. The supported TEMPO was water soluble and displayed excellent activity in the selective oxidation of alcohols below the LCST and can be easily recovered.     

DESs/SG催化剂的制备及其氧化脱硫性能

通过溶胶-凝胶法将脯氨酸基低共熔溶剂负载到硅胶上制得DESs/SG型催化剂。采用FT-IR、XRD、SEM/EDS及N₂吸附-脱附等手段对催化剂的结构进行表征。结果发现,低共熔溶剂可以成功负载到硅胶中,硅胶的比表面积和孔体积有所下降,而孔径增大。以DESs/SG为吸附剂和催化剂,H₂O₂为氧化剂,研究其对模拟油中的二苯并噻吩的脱除性能,考察了低共熔溶剂负载量、反应温度、n(H₂O₂)/n(S)比、催化剂用量、含硫化合物的类型以及催化剂循环使用次数对脱硫效率的影响。结果表明,在最优脱硫条件下,DESs/SG对二苯并噻吩、4,6-二甲基二苯并噻吩和苯并噻吩的脱硫率分别为97%、96. 5%和46. 4%;催化剂循环使用九次后,催化脱硫效率仍高达89. 4%。     

CeOx doping on a TiO2-SiO2 supporter enhances Ag based adsorptive desulfurization for diesel

In this work, the impact of CeO_x doping on a TiO₂-SiO₂ supporter on the Ag based adsorptive desulfurization for Chinese standard diesel was studied. The dispersion and valence states of Ce, Ti and Ag species were characterized, and the impact of Ce doping was investigated. The results indicated that Ce species and Ti species were dispersed evenly on the surface of SiO₂ via a novel co-impregnation method. Following CeO_x doping, the Ag species were in the form of oxides (about 5nm) instead of metallic Ag particles (about 35nm), which is due to the large amount of coordinative unsaturated sites provided by the interaction between CeO_x and TiO₂, as well as the oxidation-reduction property of CeO_x. The Ag in the active oxide state (Ag₂O₂) and dispersed evenly on the supporter could interact with sulfur compounds more favorably, and therefore showed a good performance in the adsorptive desulfurization. In both static batch and dynamic breakthrough desulfurization tests, Ag-CeO_x/TiO₂-SiO₂ was proved to be a more efficient adsorbent compared with Ag-TiO₂-SiO₂. It was found that the desulfurization performance of Ag-TiO₂-SiO₂ exhibited an excellent improvement (22.5%) after being doped with CeO_x. In the static equilibrium tests, the equilibrium sulfur capacity of Ag-CeO_x/TiO₂-SiO₂ was up to 5.38mg/g for CN-II diesel (sulfur content 952.9mg/kg) and the sulfur content of the CN-IV diesel (sulfur content 39.0mg/kg) after desulfurization was less than 10mg/kg, which could meet the CN-V standard.