TiO_2载体在柴油加氢脱硫中的应用进展

从改变催化剂载体性质的角度出发,介绍了TiO2作为柴油加氢脱硫催化剂载体的优越性,综述了TiO2载体的成型及其在柴油加氢脱硫过程中的应用状况。TiO2载体的成型已取得了很大的进展,基本可满足柴油加氢精制过程对载体的要求。提高以TiO2为载体的柴油加氢脱硫催化剂的性能主要有以下几种方法:(1)采用镧、铈等过渡金属对载体进行改性;(2)采用助剂对催化剂进行修饰;(3)采用大比表面积的纳米TiO2或TiO2纳米管作为载体。今后的发展方向仍将致力于TiO2成型载体性能的提高以及高活性Co(Ni)Mo/TiO2催化剂制备新方法的研究上,以适应柴油深度加氢脱硫的要求。     

复合SiO_2-Al_2O_3载体制备及其在柴油深度加氢脱硫中的应用

采用不同方法制备系列复合SiO_2-Al_2O_3载体,以等体积浸渍法负载硝酸镍和钼酸铵溶液制得加氢脱硫催化剂。通过BET、XRD和NH3-TPD对载体进行表征,并以直馏柴油为原料,考察不同载体对催化剂加氢脱硫活性的影响。结果表明,以硅质量分数27%的Si-Al-2载体负载浸渍液制得的催化剂具有较高的加氢脱硫活性,346℃可以将柴油中的硫含量脱除至小于10μg·g-1,加氢脱硫活性较对比剂有很大提高。     

柴油加氢脱硫RS-1100催化剂的工业生产与应用

中国石油化工股份有限公司石油化工科学研究院为进一步提高柴油加氢脱硫催化剂性能,降低催化剂成本,增强市场竞争力,成功开发了新型NiMo类柴油超深度加氢脱硫RS-1100催化剂,并进行了工业生产,获得成功应用。中国石油化工股份有限公司济南分公司工业应用结果表明,RS-1100催化剂在较低反应温度下具有较高的脱硫、脱氮活性,能够满足生产国Ⅲ和国Ⅳ标准柴油要求。中国石油化工股份有限公司沧州分公司工业应用结果表明,RS-1100催化剂具有良好的加氢脱硫和加氢脱氮活性,能够满足生产国Ⅲ标准柴油要求,并有进一步提高油品质量的空间。     

加氢法与生物法联合脱除催化柴油有机硫探索实验

由于存在空间位阻,二苯并噻吩(DBT)及其烷基化衍生物(Cx-DBT)中的硫原子很难与加氢催化剂接触.因此,作为柴油脱硫的主要工艺,加氢催化对于柴油中的主要有机硫化物DBT和Cx-DBT的脱除率比较低,难以实现深度脱硫.针对硫质量分数为3 358 μg/g的催化柴油,采用加氢脱硫与生物脱硫相结合的办法进行处理后,催化柴油的硫质量分数降低到20μg/g以下,使用气相色谱-原子发射仪对柴油脱硫前后的硫分布进行检测,发现2种工艺的结合能有效地脱除催化柴油组分中绝大多数的DBT和Cx-DBT,显示出良好的应用前景.     

柴油深度脱硫中的反应工程问题及对策

柴油深度脱硫受到3个反应工程问题的限制:一是反应速率级数对总硫浓度呈二级,因此在硫浓度很低时加氢脱硫速率极慢;二是4,6-二甲基二苯并噻吩(4,6-DMDBT)的甲基取代基有空间位阻,需采取先加氢、后氢解的途径;三是脱硫反应受到硫化氢的抑制作用,特别在硫浓度很低时,硫化氢的抑制作用更加明显。为了获得超低硫柴油(<50μg/g),根据反应工程原理,气液逆流加氢操作是一种有效的方式。     

Deep hydrodesulfurization of diesel fuel: Design of reaction process and catalysts

Deep hydrodesulfurization (HDS) of diesel fuel oil was designed based on the recognition that alkyl dibenzothiophenes such as 4-methyl-and 4,6-dimethyldibenzothiophenes were the main target for deep HDS. Multi-stage and fractional HDS were very effective to achieve satisfactory HDS in terms of both sulfur level and fluorescent color of desulfurized oil. Catalysts with the selective hydrogenation of refractory sulfur species in major aromatic partners and isomerization-disproportionation of their alkyl groups prior to HDS were also designed to promote the desulfurization of such sulfur species.     

Kinetics toward mechanism and real operation for ultra-deep hydrodesulfurization and hydrodenitrogenation of diesel

As the hydrodesulfurization (HDS) of diesel achieves ultra-deepness, our understanding of its kinetics is still far from in-depth. Therefore, herein, two lumped kinetic models for the ultra-deep hydrodesulfurization (UHDS) and hydrodenitrogenation (HDN) are established based on experiments under a wide range of operating conditions. Meanwhile, a four-lump kinetic model of the aromatic hydrosaturation (AHS) is erected. Our kinetic models disclose thermodynamic decisiveness in UHDS, which is unreachable beyond a temperature upper limit or a pressure lower limit. We also reveals the unexpected temperature dependence of organonitrogen inhibition to HDS, for less than 300°C this inhibition becomes even more potent despite nitrogen removal by HDN reactions. Subsequently, the HDS kinetics of total sulfur are deciphered as multi stages existed in the whole reaction coordinate. Accordingly, a four-stage conceptual model involving mechanism and rate laws is proposed to better understand organonitrogen inhibition, thermodynamics, and kinetics in UHDS.     

Biodiesel from safflower oil and its application in a diesel engine

Safflower seed oil was chemically treated by the transesterification reaction in methyl alcohol environment with sodium hydroxide (NaOH) to produce biodiesel. The produced biodiesel was blended with diesel fuel by 5% (B5), 20% (B20) and 50% (B50) volumetrically. Some of important physical and chemical fuel properties of blend fuels, pure biodiesel and diesel fuel were determined. Performance and emission tests were carried out on a single cylinder diesel engine to compare biodiesel blends with petroleum diesel fuel. Average performance reductions were found as 2.2%, 6.3% and 11.2% for B5, B20 and B50 fuels, respectively, in comparison to diesel fuel. These reductions are low and can be compensated by a slight increase in brake specific fuel consumption (Bsfc). For blends, Bsfcs were increased by 2.8%, 3.9% and 7.8% as average for B5, B20 and B50, respectively. Considerable reductions were recorded in PM and smoke emissions with the use of biodiesel. CO emissions also decreased for biodiesel blends while NO_x and HC emissions increased. But the increases in HC emissions can be neglected as they have very low amounts for all test fuels. It can be concluded that the use of safflower oil biodiesel has beneficial effects both in terms of emission reductions and alternative petroleum diesel fuel.     

Preparation and catalytic performance of modified kaolin clay with big pore for the hydrodesulfurization of diesel

A kind of metakaolin materials with big pores was prepared from natural kaolin clays. The prepared metakaolin was introduced into alumina as composite support for hydrotreating application. A series of nickel–tungsten catalysts (NiO 2.9 wt%, WO₃ 27.2 wt%) supported on alumina-metakaolin, alumina-titania and bare alumina also were prepared. Electron microprobe analysis including SEM and TEM, BET and temperature programmed desorption of NH₃ were used for the samples characterization. Their hydrodesulfurization (HDS) activity for diesel were evaluated and compared. The results showed that NiW/alumina-metakaolin had excellent HDS activity and alumina-metakaolin support could be a good candidate support for hydrotreating catalysts.     

A theory of ultradeep hydrodesulfurization of diesel in stacked‐bed reactors

Hydrodesulfurization catalysts have two types of active sites for hydrogenation and hydrogenolysis reactions. While hydrogenation sites are more active for desulfurizing refractory sulfur species, they are more susceptible to organonitrogen inhibition than hydrogenolysis sites. In contrast, hydrogenolysis sites are more resistant to organonitrogen inhibition but are less active for desulfurizing refractory sulfur species. This dichotomy is exploited to develop an ultradeep hydrodesulfurization stacked‐bed reactor comprising two catalysts of different characteristics. The performance of such a catalyst system can be superior or inferior to that of either catalyst alone. A mathematical model is constructed to predict the optimum stacking configuration for maximum synergies between the two catalysts. The best configuration provides the precise environment for the catalysts to reach their full potentials, resulting in the smallest reactor and minimum hydrogen consumption. Model predictions are consistent with experimental results. A selectivity‐activity diagram is developed for guiding the development of stacked‐bed catalyst systems. © 2017 American Institute of Chemical Engineers AIChE J, 64: 595–605, 2018     

柱撑粘土在加氢脱硫中的应用研究

以柱撑粘土为载体,制备了Mo-Ni／A1-Fe-PILC和Mo—Ni／AbPILC加氢脱硫催化剂,在50m愀型固定床反应评价装置中对FCC汽油进行加氢脱硫研究。结果表明：Mo-Ni／A1-Fe-PILC和Mo-Ni／A1-PILC2种催化剂具有较好的加氢脱硫效果,脱硫率达到75％以上,最佳的工艺条件为反应温度340℃,反应压力6．0MPa,空速为4．0h-1。     

TiO2及其复合载体在加氢脱硫中的应用研究进展

本文对TiO2载体的应用情况作了综述,并对TiO2与传统载体的使用性能进行对比,指出了TiO2载体的优势和存在的问题,并提出了解决问题的方法。     

汽油和柴油中含硫化合物加氢脱硫反应机理研究进展

环境保护意识的大幅度提升促使车用燃料质量标准日益严格,为实现汽油和柴油中硫含量不断降低的目标,迫切需要研发超深度脱硫技术.目前加氢脱硫技术是大规模工业化应用的关键技术,其核心是高效催化剂的研制.介绍了FCC汽油及柴油中所含各类硫化物的加氢脱硫反应路径,主要讨论了其中难以脱除的噻吩类、苯并噻吩类、二苯并噻吩类和4,6-二...     

微波合成锂皂石的结构与性能及其应用

天然形成的锂皂石资源中国非常稀少，为了满足化妆品、牙膏及特种涂料等行业对锂皂石的大量需求，同时为了解决以往合成锂皂石采用高温高压的高能耗方法的问题，采用微波场作用在常压条件下以水热法合成了锂皂石。经XRD和化学成分分析表明其与天然锂皂石具有极好的吻合性。镁和硅的物质的量比在0.45～0．76，可合成透明性好、纯度高的锂皂石。一般情况下，其阳离子交换容量越大，其粘度也越大。经在牙膏中应用实验表明，合成锂皂石与羧甲基纤维素（CMC）混合后可大大地改善牙膏的膏体性能。     

RFCC柴油非加氢精制技术及其应用

采用多种非加氢手段对RFCC柴油进行精制。在油品中加入少量酚类或胺类物质能终止自 由基链反应;某些活性固体物质对碱性氮有良好的吸附能力;在极性环境中能进一步萃取含氮、硫杂质。 四种复合非加氢技术精制的柴油指标达GB252-2000标准要求。     

Synthesis and catalytic performance of novel hierachically porous material beta-MCM-48 for diesel hydrodesulfurization

Novel hierachically porous material Beta-MCM-48 was successfully synthesized from Beta zeolite seeds by two-step hydrothermal crystallization method using Cetyltrimethylammonium Bromide as the mesostructure directing agent. Beta-MCM-48 composite synthesized at the optimization conditions possessed Beta microporous structure and cubic Ia $ \overline{ 3} $ 3 ¯ d mesoporous structure simultaneously. Meanwhile, the acidity of Beta-MCM-48 was similar to Beta zeolite and higher than MCM-48 mesoporous material. A series of Al₂O₃-Beta-MCM-48 supported NiMo catalysts with different Beta-MCM-48 contents were prepared by the incipient-wetness impregnation method. The catalytic performances were evaluated using DaQing Fluid Catalytic Cracking diesel as feedstock in a high pressure microreactor. Hydrodesulfurization results indicated that NiMo/Al₂O₃-Beta-MCM-48 catalyst exhibited better activities than that of NiMo/Al₂O₃ traditional catalyst. NiMo/Al₂O₃-Beta-MCM-48 catalyst obtained the highest activity as the Beta-MCM-48 content in the support was 20 wt %, and the corresponding sulfur content of the hydrotreated product reached to 23.02 μg g^?1.     

改性杏壳活性炭的制备及其在柴油脱硫中的应用

以杏壳活性炭为原料,分别经过10%和37%的硝酸以及盐酸改性后得到10%HNO_(3)-GAC、37%HNO_(3)-GAC、10%HCl-GAC、37%HCl-GAC;通过负载钴离子得到Co/GAC。采用SEM和FT-IR对改性活性炭的成分和结构进行分析表征,并以苯并噻吩为溶质、正己烷为溶剂配制硫质量分数为0.1%的模型油。将多种活性炭在相同的条件下对模型油进行脱硫并选取最佳脱除剂,结果表明,Co/GAC的脱硫效果最好。通过单因素分析得Co/GAC单变量情况下的最佳条件,选择Co/GAC作为脱除剂采用响应面法优化脱除柴油中的硫化物,在脱除时间、剂油比、pH值的单因素基础上,以响应面实验模型验证的方法,确定工艺优化参数。其最优条件是:脱除时间3.4 h,剂油比0.08,pH=3.5。在此条件下,脱硫率为55.4%。选取Freundlich模型和Langmuir模型两种吸附等温线对298 K条件下Co/GAC吸附模型油中硫过程中的数据进行拟合,拟合结果表明,Langmuir模型可以更好的描述Co/GAC吸附模型油脱硫过程。     

多元复合柴油的制备和应用

综述多元复合柴油的特性和制备,简单阐述多元复合柴油在柴油车上的应用,多元复合柴油是一种微乳状液,它的作用已引起许多科学家的重视,有良好的推广应用前景。     

Characterizations of surfactant synthesized from Jatropha oil and its application in enhanced oil recovery

Surfactants are frequently used in chemical enhanced oil recovery (EOR) as it reduces the interfacial tension (IFT) to an ultra‐low value and also alter the wettability of oil‐wet rock, which are important mechanisms for EOR. However, most of the commercial surfactants used in chemical EOR are very expensive. In view of that an attempt has been made to synthesis an anionic surfactant from non‐edible Jatropha oil for its application in EOR. Synthesized surfactant was characterized by FTIR, NMR, dynamic light scattering, thermogravimeter analyser, FESEM, and EDX analysis. Thermal degradability study of the surfactant shows no significant loss till the conventional reservoir temperature. The ability of the surfactant for its use in chemical EOR has been tested by measuring its physicochemical properties, viz., reduction of surface tension, IFT and wettability alteration. The surfactant solution shows a surface tension value of 31.6 mN/m at its critical micelle concentration (CMC). An ultra‐low IFT of 0.0917 mN/m is obtained at CMC of surfactant solution, which is further reduced to 0.00108 mN/m at optimum salinity. The synthesized surfactant alters the oil‐wet quartz surface to water‐wet which favors enhanced recovery of oil. Flooding experiments were conducted with surfactant slugs with different concentrations. Encouraging results with additional recovery more than 25% of original oil in place above the conventional water flooding have been observed. © 2017 American Institute of Chemical Engineers AIChE J, 63: 2731–2741, 2017     

Sulfidation of an aluminum-nickel-molybdenum catalyst and its activity in thiophene hydrodesulfurization

We consider the interaction of H₂S with the molybdenum component of the catalyst using an Mo₇O₂₄H₁₂ cluster as an example. At 200–300°C, SH groups substitute for OH groups of the molybdenum component. Intense reduction of the molybdenum component starts at 300°C. The reaction of hydrogen with the molybdenum component at 300°C generates Mo-H hydride groups, Mo⁵⁺ ions, and anionic vacancies; these vacancies are filled in by sulfur anions produced by the dissociation of hydrosulfuric acid. An NiMoO₄ crystal phase is reduced and completely sulfided at 300°C. Mo₇O₂₄H₁₂ clusters are sulfided only partially; complete substitution by sulfur does not occur in them even at 600–650°C. We consider the thiophene hydrodesulfurization scheme on molybdenum oxysulfide in the presence of nickel, as well as the scheme of this reaction on MoS₂ in the absence of nickel. We conclude that hydrodesulfurization and hydriding occur at the same sites. Catalytically active surface sites in Mo₇O _x S _y + Ni, MoS₂ + Ni, and MoS₂ structures are alike. A common feature of these structures is the existence of Mo-H⁻ and MoSH⁻ basic sites. The difference between them lies in the nature of proton-donor sites: in MoS₂, proton donors are Mo-S-H⁺ groups, whereas in nickel-containing structures, nickel crystallites reacting with hydrogen are generators of protons and hydride ions.