Catalytic Performance of Aquathermolysis and Viscosity Reduction of Heavy Oil over a WO_(3)/ZrO_(2) Solid Acid

Tungstated zirconia(WO_(3)/ZrO_(2))solid acid catalysts with different WO_(3) contents were prepared by a hydrothermal method and then used in the catalytic aquathermolysis of heavy oil from Xinjiang.The WO_(3)/ZrO_(2) solid acid catalyst was characterized by a range of characterization methods,including X-ray diffraction,NH3-temperature programmed desorption,and pyridine infrared spectroscopy.The WO_(3) content of the WO_(3)/ZrO_(2) catalysts had an important impact on the structure and property of the catalysts.When the WO_(3) mass fraction was 20%,it facilitated the formation of tetragonal zirconia,thereby enhancing the creation of robust acidic sites.Acidity is considered to have a strong impact on the catalytic performance of the aquathermolysis of heavy oil.When the catalyst containing 20%WO_(3) was used to catalyze the aquathermolysis of heavy oil under conditions of 14.5 MPa,340℃,and 24 h,the viscosity of heavy oil decreased from 47266 to 5398 mPa·s and the viscosity reduction rate reached 88.6%.The physicochemical properties of heavy oil before and after the aquathermolysis were analyzed using a saturates,aromatics,resins,and asphaltenes analysis,gas chromatography,elemental analysis,densimeter etc.After the aquathermolysis,the saturate and aromatic contents significantly increased from 43.3%to 48.35%and 19.47%to 21.88%,respectively,with large reductions in the content of resin and asphaltene from 28.22%to 25.06%and 5.36%to 2.03%,respectively.The sulfur and nitrogen contents,and the density of the oil were significantly decreased.These factors were likely the main reasons for promoting the viscosity reduction of heavy oil during the aquathermolysis over the WO_(3)/ZrO_(2) solid acid catalysts.

甲烷低温活化机理及其参与的化学反应研究进展

基于甲烷在400~600℃时与其他烃类原料共反应可出现低温活化现象,综述了此过程中甲烷的不同活化机理和反应路径,总结了甲烷在低温活化后参与的重质油改质反应、烯烃加氢反应、低碳烃芳构化反应以及含氧化合物的脱氧芳构反应等不同类型反应的特征、共反应助剂的作用和催化剂的催化作用等方面的研究进展。总结发现,虽然甲烷与其他原料共反应过程的活化机理和参与路径不同,但均可认为甲烷在其他大分子烃类的促进下发生低温活化并参与到相关反应中,起到供氢、增碳和优化产物分布等作用。尤其是在甲烷参与的芳构化反应过程中,甲烷的参与可以起到改善产物分布、提高甲基侧链产物选择性等多方面的作用,这可为甲烷低成本利用技术的开发提供良好的研究基础。

活性金属对含甲烷氛围稠环芳烃加氢转化性能的影响

在Hβ分子筛上负载不同活性金属制备了系列催化剂,利用GC、XRD、N2吸附-脱附、Py-IR、NH_(3)-TPD等方法对催化剂进行了表征,并以萘为模型化合物,考察了催化剂在CH_(4)-H_(2)混合气氛下对稠环芳烃加氢裂化反应过程的影响。实验结果表明,负载的活性金属均可以均匀分散在Hβ分子筛表面,促进萘加氢开环,萘转化率均达到80%以上。其中,Zn/Hβ,Cu/Hβ,Co/Hβ催化剂的主要产物为甲苯和二甲苯,表明CH_(4)被活化并参与了反应,提高了含甲基侧链芳烃的加氢裂化产物选择性。尤其是Zn/Hβ催化剂,在CH_(4)-H_(2)气氛下,表现出高液相收率和高苯-甲苯-二甲苯混合物选择性,分别为91.34%和56.78%。研究结果可为重质油和天然气资源的高效利用提供新的方向。

Selective Hydrogenation of Polycyclic Aromatics to Monocyclic Aromatics over NiMoC/HβCatalysts in a Methane and Hydrogen Environment

To obtain high yields of monocyclic aromatic hydrocarbons with methyl side chains,such as toluene and xylene,methane(CH_(4))can be introduced into the hydrocracking of polycyclic aromatic hydrocarbons.CH_(4)can participate in the reaction,supply methyl side chains to the product,and improve product distribution.In this study,the hydrogenation reaction of polycyclic aromatic hydrocarbons over a carbonized NiMo/Hβcatalyst in a CH_(4)and hydrogen(H_(2))environment was investigated to study the promotional effect of CH_(4)on the hydrocracking of polycyclic aromatics.Under conditions of 3.5 MPa,380℃,volume air velocity of 4 h^(-1),gas-oil volume ratio of 800,and H_(2):CH_(4)molar ratio of 1:1,the conversion rate of naphthalene was 99.97%,the liquid phase yield was 93.62%,and the selectivity of BTX were 17.76%,25.17%,and 20.47%,respectively.In comparison to the use of a H_(2)atmosphere,the selectivity of benzene was significantly decreased,whereas the selectivity of toluene and xylene were increased.It was shown that CH_(4)can participate in the hydrocracking of naphthalene and improve the selectivity of toluene and xylene in the liquid product.The carbonized NiMo/Hβcatalyst was characterized by a range of analytical methods(such as X-ray diffraction(XRD),ammonia-temperature-programmed desorption(NH3-TPD),hydrogen-temperature-programmed reduction(H_(2)-TPR),and X-ray photoelectron spectroscopy(XPS)).The results indicated that Ni and Mo carbides were the major species in the carbonized NiMo/Hβcatalyst and were considered to be active sites for the activation of CH_(4)and H_(2).After loading the metal components,the catalyst displayed prominent weak acidic sites,which may be suitable locations for cracking,alkylation,and other related reactions.Therefore,the carbonized NiMo/Hβcatalyst displayed multiple functions during the hydrocracking of polycyclic aromatic hydrocarbons in a CH_(4)and H_(2)environment.These results could be used to develop a new way to efficiently utilize polycyclic aromatic hydrocarbons and natural gas resources.

甲烷对稠环芳烃加氢裂化反应的促进作用

通过湿浸渍法制备负载型Zn-Ag/Hβ催化剂,采用XRD、SEM、XPS、Py-IR、NH_(3)-TPD和N_(2)吸附-脱附等手段进行表征。在稠环芳烃的加氢裂化反应过程引入甲烷,研究了甲烷对Zn-Ag/Hβ催化剂作用下稠环芳烃的加氢裂化反应过程的促进作用,并考察了甲烷引入比例、反应温度、反应压力等条件对稠环芳烃加氢反应萘转化率和苯、甲苯、二甲苯(BTX)等产物选择性的影响规律。结果表明:Zn-Ag/Hβ催化剂具有丰富的中强酸中心,负载金属Zn后分子筛存在Zn^(2+)和进入分子筛晶体骨架的Zn物种,总酸量降低且Lewis/Bronsted(L/B)酸量比增加;在反应压力3.5 MPa、反应温度400℃、体积空速4 h^(-1)、气/油体积比800、氢气和甲烷混合气氛的条件下,以萘为模型化合物在Zn-Ag/Hβ催化剂的作用下进行加氢裂化反应,萘转化率为99.82%,液体收率为80.88%;与氢气气氛下相比,BTX总选择性、苯、甲苯和二甲苯的选择性均显著提高。甲烷参与反应对提高BTX选择性和液相收率有利,促进了萘加氢裂化反应产物中含有甲基侧链产物的选择性,该研究结果为高效利用宝贵的重质油资源提供一个新的途径。

以竞赛为驱动项目为依托的化工设计基础课程教改研究——以西安石油大学为例

在工程教育专业认证的大背景下,化工设计基础课程作为化工专业教育核心课程,坚持以全国大学生化工设计竞赛为驱动来充分挖掘学生潜能,采用化工设计项目作品展示方式全面推动学生专业综合能力培养,并基于虚拟仿真实验教学平台、化工过程实景仿真实训装置以及现代化工设计手段开展丰富多彩的特色课程改革研究,以达到不断激发学生学习动机、优化课程考核方式、提升课程教学质量的目的。

分子筛改性对噻吩烷基化反应性能的影响

介绍了催化裂化(FCC)汽油中噻吩烷基化脱硫及其反应机理,综述了分子筛经水热处理、碱处理、酸处理、负载金属离子等不同改性方法改性后,对分子筛孔道结构、表面酸性以及催化FCC汽油中噻吩烷基化反应性能的影响。同时比较总结了上述各类改性方法的优缺点,以期对FCC汽油噻吩烷基化脱硫催化剂的研发提供有益的借鉴和指导。

无机铝源合成有序介孔氧化铝的影响因素研究

有序介孔氧化铝具有较大的比表面积、均匀且窄的孔径分布、有序的孔结构等特点,在多相催化反应及吸附分离过程中具有十分重要的应用价值,研究其合成及应用具有重要意义。以廉价的无机铝盐为铝源,结合模板剂,利用溶胶-凝胶法,通过改变模板剂的种类、老化时间和温度等影响因素,制备有序介孔氧化铝。采用多种测试技术对其结构进行表征,探讨不同反应条件对合成有序介孔氧化铝结构的影响规律。结果表明,以二正丙胺为模板剂,在40℃条件下老化48 h,可合成比表面积为324.80 m 2·g^(-1),孔容为0.62 cm 3·g^(-1),平均孔径为6.07 nm的介孔氧化铝,且孔径分布较窄,孔道有序性良好。

负载型磷化镍催化剂的制备及其催化应用

综述了近年来负载型磷化镍催化剂在制备方法(还原法、热解法和溶剂热法)、活性组分和载体改性及其催化应用方面的研究进展,并对比了各种制备方法的优缺点,其中还原法流程简单,但所用温度较高,时间较长;热解法所需温度较低,制备过程简单,但易于生成副产物水;而溶剂热法具有所需温度低,物相形成过程易控制等优点。负载型磷化镍催化剂由于其良好的加氢氢解及烷烃临氢异构化等反应性能,是一类更加廉价的新型催化剂,具有很好的发展前景。

中药有效成分对心肌细胞毒性作用机制的研究进展

心脏毒性评价是各类新药进入临床试验前必须考量的重要指标,然而具有心脏毒性中药的物质基础仍不明确,且不同中药有效成分对心肌细胞的毒性机制不尽相同,因此了解中药有效成分对心肌细胞的毒性及机制,对于中药药物安全评价以及对中药心脏毒性研究具有至关重要的作用.本文综述乌头碱、雷公藤甲素、蟾酥甾烯类物质和乙酰紫草素等中药有效成分对心肌细胞的作用及机制.

The Caustic Alkali-free Water Extraction Agents for Treating Inner Mongolia Oil Sands

The caustic alkali-free water extraction agents were studied for treating the oil sands excavated from Inner Mongolia, China. Several kinds of chemical reagents were evaluated, among which sodium carbonate(SC), sodium dodecyl benzene sulfonate(SD) and sodium chloride were confirmed as composite solutes. Their proportion was optimized by an orthogonal test. The optimum proportion of the composite agent covered 0.03% of SD, 0.50% of sodium chloride, 3.00% of SC, with the rest composed of water. The optimal operating condition was also confirmed. The oil sands were extracted at the following optimized conditions: a treating time of 15 min, a temperature of 80 ℃ and an extraction agent/feed ratio of 1:1, with the bitumen yield reaching more than 96%. The extraction agent after separation from the bitumen product can be recycled for reuse to carve out a good environmentally friendly route.

Effect of Sulfurization Temperature on Thioetherification Performance of Mo-Ni/Al_2O_3 Catalyst

The Mo modified Ni/Al_2O_3 catalysts were prepared and sulfided at different temperatures, and their catalytic activity for thioetherification of mercaptans and olefins(or dienes), hydrogenation of dienes and olefins in the thioetherification process using fluidized catalytic cracking(FCC) naphtha as the feedstock was investigated. In order to disclose the correlation between the physicochemical characteristics of catalysts and their catalytic activity, the surface structures and properties of the catalysts sulfided at different temperatures were characterized by the high resolution transmission electronic microscopy(HRTEM), X-ray photoelectron spectroscopy(XPS) and H2-temperature programmed reduction(H_2-TPR) technique. The results showed that an increase of sulfurization temperature not only could promote the sulfurization degree of active metals on the catalysts, but also could adjust the micro-morphology of active species. These changes could improve the catalytic performance of thioetherification, and hydrogenation of dienes and olefins. However, an excess sulfurization temperature was more easily to upgrade the ability of the catalyst for hydrogenation of olefins, which could lead to a decrease of the octane number of the product. It was also showed that a moderate sulfurization temperature not only could improve the catalytic performance of thioetherification and hydrogenation of dienes but also could control hydrogenation of olefins.