Oxidative desulfurization of straight-run diesel fraction on vanadium–molybdenum catalysts

It has been shown that the most appropriate and simple process for desulfurization of motor fuels is the direct oxidation of sulfur compounds with atmospheric oxygen on heterogeneous catalysts based on transition metal oxides. The feasibility of oxidation of thiophene with atmospheric oxygen in a model mixture with dodecane over vanadium–molybdenum catalysts has been shown, as well as that of oxidative desulfurization of actual straight-run diesel fraction. The activity of a number of samples of oxidative of desulfurization catalysts has been examined, the composition of the most effective catalyst has been determined, and optimum process conditions have been found.     

铁酸锌负载磷钨酸催化氧化噻吩脱硫研究

以噻吩溶液为模型化合物,铁酸锌负载磷钨酸为催化剂,考察氧化时间、氧化温度、磷钨酸负载量、催化剂活化温度等工艺条件对脱硫率的影响。研究结果表明：催化剂上磷钨酸的最佳负载量（w）为13%、活化温度为250 ℃;适宜的反应条件为：反应温度40 ℃,反应时间210 min,氧化剂用量n(H2O2):n(S)=5。在上述条件下模型化合物的脱硫率达到90.1%。     

生产清洁汽柴油燃料脱硫工艺的进展

介绍了国外汽、柴油燃料含硫新规范和汽、柴油脱硫技术进展，包括催化裂化进料预处理，催化裂化脱硫催化剂和助剂的开发，加氢脱硫后处理，以及深度脱硫的新途径。     

直馏柴油选择催化氧化脱硫催化剂的制备与评价

制备了直馏柴油催化氧化脱硫催化剂苯甲酸锌、B2O3和复合催化剂FTS-1。以O2为氧化剂,考察了3种催化剂催化氧化直馏柴油中的硫化物的脱硫效果。研究结果发现,苯甲酸锌催化剂脱硫效果明显,脱硫后直馏柴油中的硫含量达到小于300μg/g的欧洲Ⅱ类排放标准;B2O3催化剂脱硫效果差,但萃取柴油的收率较高;复合催化剂FTS-1可选择催化氧化直馏柴油,抑制烃类化合物的深度氧化,降低氧化柴油的酸值,极大地改善了脱硫柴油的质量,提高脱硫柴油的收率。在搅拌转速700r/m in、苯甲酸锌质量分数0.15%、B2O3质量分数2%、反应温度150℃、氧气压力1.3M Pa、反应时间60m in的条件下,复合催化剂FTS-1脱硫后直馏柴油中硫含量可降到271μg/g,脱硫率达到87.8%。     

非加氢深度脱除燃料油中硫化物的研究进展

综述了非加氢深度脱除燃料油中硫化物的技术进展,主要包括吸附脱硫技术、萃取脱硫技术和氧化脱硫技术。吸附脱硫技术对硫化物的选择性较差,且很难达到深度脱硫目的;而萃取脱硫的溶剂选择较难,且萃取的硫化物类型较少以及溶剂回收较难,使得萃取脱硫技术难以实现工业化。氧化脱硫技术具有操作条件温和,操作费用低,脱硫率高,不产生二次污染等特点,尤其以钛硅分子筛为催化剂、双氧水为氧化剂对燃料油的氧化脱硫能达到较理想的效果,是近期最有希望实现工业化以及零硫目标的脱硫技术,但氧化剂的类型和催化剂还有待进一步改进。     

催化裂化柴油氧化萃取脱硫工艺研究

以氧气作氧化剂,甲酸作催化剂,N-甲基吡咯烷酮（NMP）作萃取剂,采用催化氧化反应与溶剂萃取相结合的方法对催化裂化柴油进行了氧化萃取脱硫实验。通过单因素实验考察了催化剂用量,催化氧化温度、时间、氧气压力及萃取剂的用量等对催化裂化柴油硫含量的影响。通过实验得出最适宜的脱硫条件为：反应温度80℃;反应时间90min;充氧压力0．6MPa;催化剂体积分数为10％。经催化氧化,柴油硫质量分数可从1694．2μg/g降到190．8μg/g,脱硫率达到88．7％;在剂油比为1．0和室温条件下,用NMP三级萃取,柴油硫质量分数为37．5μg/g,小于50μg/g,达到欧Ⅳ排放标准的要求。     

燃料油萃取脱硫技术研究进展

阐述了燃料油中硫化物萃取脱除的原理,综述了国内外萃取脱除燃料油中硫化物的技术进展。萃取脱硫法相对于其它脱硫方法具有操作简单、投资成本低和辛烷值损失小等优点。针对常规酸碱洗涤法和有机溶剂萃取法存在的问题,将新型的离子液体作为溶剂应用于燃料油脱硫的研究中具有非常大的发展前途;膜科学作为一门新的科学,近年来得到了深入的研究,运用膜萃取技术来脱除燃料油中的硫化物是今后科研工作者努力的方向之一;将其它方法与萃取脱硫法进行耦合也具有较大的发展前景。     

Study on Desulfurization of Gasoline by Electrochemical Oxidation and Extraction

In order to further reduce the sulfur content in gasoline, a new desulfurization process was proposed by using catalytic oxidation and extraction realized in an electrochemical fluidized reactor. The fluidized layer of loaded catalyst particles consisted of lead dioxide (PbO2) supported on activated carbon particles (PbO2/C) and the electrolyte was aqueous NaOH solution. The PbO2/C particle anodes could remarkably accelerate the electrochemical reaction rate and promote the electrochemical catalysis of sulfur compounds. The sulfur compounds were at first oxidized to sulfones or sulfoxides, which were then re- moved after extraction. The experimental results indicated that the optimal desulfurization conditions were as follows: The cell voltage was 3.2 V, the concentration of hydroxyl ions in electrolyte was 0.12 mol/L, and the feed rate was 300 mL/min. Under these conditions the concentration of sulfur in gasoline was reduced from 310 ppm to 70 ppm. Based on these experimental results, a mechanism of indirect electrochemically catalytic oxidation was proposed.     

Fabrication of oxygen-defective tungsten oxide nanorods for deep oxidative desulfurization of fuel

Owing to the increasingly serious environmental issues caused by the sulfur burnt in fuel, desulfurization has become an important topic. In this work, an amphiphilic oxygen-defective tungsten oxide was synthesized by a colloidal chemistry method. The amphiphilic property and oxygen defects were well characterized, and the structure of the oxygen-defective tungsten oxide catalyst was investigated. In addition, the catalyst was employed in oxidative desulfurization system of fuel, and deep desulfurization was achieved. It was found that the very high oxidative desulfurization performance of oxygen-defective tungsten oxide catalyst resulted from both the amphiphilic property and oxygen defects. This work can provide a strategy for preparation of highly active metal oxide catalysts with oxygen defects in oxidative desulfurization reaction of fuel.     

机动车燃油的脱硫技术及机理

介绍了世界燃油质量标准,简要报道了机动车用汽、柴油中硫化物的种类和含量,详细报道了燃油的加氢、生物、氧化和吸附脱硫机理及技术。噻吩类化合物占汽油总含硫量的83%,柴油中的硫主要以苯并噻吩及二苯并噻吩形式存在。吸附脱硫将会成为具有良好发展前景的燃油脱硫技术。插图6幅,数据表4张,参考文献37篇。     

三元低共熔溶剂促进球磨后高硫石油焦氧化脱硫

为实现高硫石油焦的有效脱硫使其“变废为宝”,本研究提出了一种基于机械球磨的高硫石油焦氧化脱硫新方法。首先使用球磨技术对高硫石油焦进行预处理,以增加石油焦的比表面积,暴露更多硫参与氧化。实验结果表明：与氧化钙共球磨后石油焦比表面积增加了8倍以上;在高硫石油焦球磨预处理的基础上,以苯磺酸基三元低共熔溶剂(DES)为反应溶剂及催化剂,30%双氧水(H₂O₂)为氧化剂,在70℃的温和条件下成功实现高硫石油焦的氧化脱硫,其硫质量分数可从4.46%降至2.09%。通过X射线衍射(XRD)、拉曼光谱(Raman)及扫描电子显微镜(SEM)探究了石油焦球磨及氧化脱硫前后结构的变化。通过傅里叶变换红外光谱(FT-IR)、X射线光电子能谱(XPS)以及XRD分析了石油焦中硫的转化。通过电子自旋共振(ESR)试验证实了苯磺酸基三元DES的催化作用。     

A Novel Technology for Desulfurization of FCC Diesel Fuels: Combination of Hydrogenation and Oxidation-assisted Ultrasound

Abstract

This new route that integrates with hydrodesulfurization (HDS) and ultra-sound-assisted oxidation desulfurization (UAODS) technology can be studied to decrease the sulfur content of high sulfuric FCC diesel fuel. In the integrating technology, the conventional HDS unit continues to produce below 500 μg/g hydrotreated diesel fuels, with UAODS unit used to make sulfur content below 50 μg/g, or even below 10 μg/g of diesel fuels. Since it has been discovered that cavitation can be originated from ultrasonic irradiation in water, ultrasound is an increasingly used tool to enhance chemical process rate. The addition of Fenton's reagent can enhance the sono-oxidative desulfurization efficiency for diesel fuels. UAODS has more advantages in removing thiophene and alkyl-thiophenes that are less reactive than other organosulfur species present in these hydrocarbon streams (e.g., alkyl sulfides, mercaptans) using HDS technology. The key to success is that the oxidative desulfurization process must be cost-effective versus the HDS revamp alternative available to refiners.     

Ultrasound assisted photocatalytic oxidative desulfurization of model diesel fuel

Ultrasound assisted photocatalytic oxidation technology is an efficient and gentle technology to remove the organic sulfur from diesel. The influence parameters of catalytic oxidation phase include catalyst dosage, reaction temperature, oxidation time, hydrogen peroxide to diesel fuel ratio and time of the extraction process. Furthermore, the comparison of the results under two conditions of ultrasound irradiation and mechanical agitation are also specially examined. The obtained results indicate that under the optimal condition, ultrasound assisted oxidative desulfurization (UAOD) is more efficient for sulfur removal which the desulfurization degree can be reached 99.47%.     

钛硅分子筛的合成与应用

简要介绍了钛硅石分子筛的合成方法和主要用途。合成方法包括水热合成法、同晶取代法及微波辐射法。钛硅沸石分子筛是性能优良的选择氧化催化剂,能使许多有机化合物选择氧化生成重要化工原料,包括苯及苯酚的羟基化,生成苯二酚和苯醌;丙烯环氧化生成环氧丙烷;酮氨肟化生成环己酮肟;苯胺氧化生成偶氮苯等及石化产品氧化脱硫,对产品性能无明显变化。     

Oxidation of Dibenzothiophene and Desulphurization of Diesel

In order to meet the future regulations, sulfur compounds have to be removed completely from fuels. A study was carried out on the process development for selective oxidation of DBT using a series of simple acid catalyst systems with hydrogen peroxide as oxidant. The sulfoxides and sulfones formed were extracted by adsorption over a silica gel column. The oxidation reactivity and mechanism were studied and explained. The optimized experimental conditions were extended to diesel for the oxidation of dibenzothiophene, 4-methyl dibenzothiophene, and 4,6-dimethyl dibenzothiophene. The sulfur reduction in diesel fuel to the desired level could be achieved using the simple mixed acid catalyst.     

燃料油氧化脱硫技术进展

综述了氧化脱硫技术中氧化剂和催化剂的研究进展。其中氧化剂包括高锰酸钾、氮化物（NO2和硝酸）、分子氧（臭氧、氧气和空气）、双氧水、有机过氧化物（过氧化叔丁醇、过氧化叔戊醇及过氧化环己酮）。催化剂主要介绍与双氧水相匹配的催化剂,分为液相催化剂和固相催化剂,液相催化剂包括甲酸、乙酸、乙酸酐或杂多酸磷钨酸;固相催化剂包括以金属氧化物为载体的固体催化剂,即WOx／ZrO2,负载在TiO2上的V2O5催化剂;以分子筛为载体的固体催化剂,即钛硅分子筛催化剂。并提出今后氧化脱硫醇技术的发展方向。     

Ozone-assisted oxidative desulfurization of light oil fractions

A catalytic system for oxidative desulfurization has been created, which is a transition metal salt bearing an organic ligand and capable of forming an active oxidative complex in the interaction with ozone and further oxidizing sulfur compounds present in fuel followed by the adsorption of the oxidation products on silica gel. In this case, a direct contact of ozone with the fuel is avoided, making the process safer. The effect of the reaction and ozonation conditions on the desulfurization process has been studied. Total sulfur content was decreased to 180 ppm for the straight-run gasoline fraction and to 900 ppm for the diesel fraction.     

One-Step Oxidation–Desulfurization of FCC Gasoline Catalyzed by Tungstophosphoric Acid

Abstract

The sulfur compounds in fluid catalytic cracked (FCC) gasoline were removed with a one-step oxidation–extraction method. Tungstophosphoric acid (HPWA), tert-butyl hydroperoxide (TBHP), and ethanol were used as catalyst, oxidant, and solvent, respectively. TBHP has a higher desulfurization degree and oil yield than hydrogen peroxide, and HPWA exhibited higher desulfurization degree and oil yield than the other kinds of acids. The one-step process has a higher desulfurization degree than the two-step process. The optimal operating parameters were obtained as follows: the catalyst amount was 5 wt%, the mole ratio of oxygen in the oxidant to the sulfur in the gasoline (O/S) was 10, the reaction temperature was 60°C, and the reaction time was 2 hr. Under these conditions, the desulfurization degree and yield of oil were both in the range of 85–90%.     

Polycrystalline Phase WO_3/g-C_3N_4 as a High Efficient Catalyst for Removal of DBT in Model Oil

The polycrystalline phase WO_3/g-C_3N_4 was synthesized under stirring using tungstenic acid(H_2WO_4) and graphitic carbon nitride(g-C_3N_4) as raw materials. The catalyst was characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),the Fourier transform infrared spectroscopy(FT-IR),and the Brunauer-Emmett-Teller analysis(BET). The polycrystalline phase WO_3/g-C_3N_4 was determined by XRD technique. The oxidative desulfurization process was investigated using WO_3/g-C_3N_4 as the catalyst, 30% hydrogen peroxide(H202) as the oxidant, and 1-butyl-3-methylimidazolium tetrafluoroborate([bmim]BF4) ionic liquids(ILs) as the extractant. The operating conditions, including H_2WO_4 amount, IL dose, H_2 O_2 volume, temperature, catalyst dosage, and types of sulfur compounds,were systematically researched. The desulfurization rate could reach 98.46% for removing dibenzothiophene(DBT) from the model oil under optimal reaction conditions. In addition, the catalytic activity was slightly decreased after five recycles of catalysts. The reaction kinetics analysis shows that the oxidative desulfurization system was in accord with the first-order reaction kinetics equation. The mechanism of oxidative desulfurization was proposed.     

混合氧化物载体对反应吸附剂Ni/ZnO的影响

The effect of mixed oxide support on the performance of the reactive adsorption desulfurization (RADS) for Ni/ZnO was invested by using thiophene in model gasoline in a fixed bed reactor. A series of oxide supports of Ni/ZnO was synthesized by co-precipitation method and characterized by XRD, N2-adsorption, TPR and NH3-TPD. It was found that the desulfurization capacity of Ni/ZnO is enhanced greatly when active components were supported on proper mixed oxide. Ni/ZnO supported on oxides exhibits much higher desulfurization efficiency and sulfur adsorption capacity than unsupported Ni/ZnO and the synthesized Ni/ZnO-SA adsorbent exhibits the highest efficiency for thiophene removal. The higher desulfurization activity and sulfur capacity of Ni/ZnO supported on SiO2-Al2O3 with small particle size, high specific surface area and large pore volume promotes the highly dispersion of active metal phase and the transfer of sulfur to ZnO with lower mass transfer resistance. γ-Al2O3 can weaken the interaction of active phases and SiO2 as well as increasing greatly the amount of weak acid. Therefore, these oxides have a great influence on the structure and chemical properties of the catalyst.