柴油加氢脱芳烃的集总动力学模型的分析研究

为了改善柴油的燃烧性能以及减少尾气污染,要求柴油向低硫、低芳烃、低密度方向发展。开发优良的加氢脱芳烃催化剂对于油品质量升级和清洁燃料生产有着重要意义。芳烃加氢反应动力学研究的主要应用就是指导工艺优化、通过动力学参数的内在联系反映出催化剂的性能,为催化剂的研制提供依据,以及与反应器相结合,为反应器的设计开发提供理论依据。结合 PA/MA 的比例以及原料氮含量对指前因子的关联修正,建立了柴油加氢脱芳烃的集总反应动力学模型,并验证了模型参数和检验模型的合理性。建立的模型可以为不同操作条件下芳烃加氢反应的预测及工艺条件优化提供准确的理论计算数据,同时也可为指导新催化剂的研制提供一定的理论基础。     

超临界流体技术制备生物柴油的研究进展

综述了超临界流体技术制备生物柴油的最新研究进展。介绍了反应机理和反应动力学、工艺操作条件、原料中的水和游离脂肪酸、共溶剂和附加催化剂对酯交换反应的影响,并提出了超临界流体技术的优势、存在问题以及发展方向。     

葵花籽油制备生物柴油的研究

介绍了在碱催化剂作用下以葵花籽油与甲醇反应生成生物柴油的工艺条件,考察了醇油摩尔比、催化剂用量、反应温度、反应时间等条件对反应的影响,采用正交实验的方法得出最佳的反应条件:醇油摩尔比6:1、催化剂用量0．9％、反应温度60℃、反应时间50 min。对所得到生物柴油的主要性能与柴油进行对比,其指标均符合0#矿物柴油标准。     

微波辅助玉米油基生物柴油制备及酯化反应动力学

以玉米油和甲醇为原料、浓硫酸作催化剂,微波辅助制备生物柴油,研究了反应时间、反应温度、催化剂体积及微波功率对玉米油酯化率的影响,在单因素实验基础上优化制备工艺,考察了酯化反应的动力学. 结果表明,微波辅助制备玉米油基生物柴油的最佳条件为反应温度72.0℃、时间17.5 min、催化剂用量为玉米油体积的8.5%和微波功率200 W,该条件下酯化率可达77.6%. 酯化反应级数为1.28,活化能Ea=1.79 J/mol,酯化反应的动力学方程为r=8.214e?1.792/RTC1.28 .     

典型碳氢化合物水蒸气重整制氢研究进展

  烃水蒸气重整是目前获取氢能源的重要方法之一,而甲烷、汽油和柴油作为典型烃类原料可满足于不同规模氢能源的需求。本文重点从催化剂、反应工艺和反应机理及动力学三个方面对甲烷、汽油和柴油蒸汽重整制氢进行介绍和评述。指出甲烷重整制氢镍基催化剂的改性和反应器设计以及反应条件的优化是其必然的发展趋势,汽油和柴油重整制氢催化剂未来设计必须具备高抗硫性和抗积炭性。此外,需加强甲烷、汽油和柴油蒸气重整制氢的机理和动力学研究。     

生产超低硫柴油的加氢脱硫催化剂级配技术

为了解决柴油超深度加氢脱硫过程受热力学平衡限制问题,更好地发挥不同类型催化剂的优势,在中型实验装置上,采用固定压力等级和空速的实验方法,考察了加氢反应活性好的W-Mo-Ni型催化剂和烷基转移反应活性好的Mo-Co催化剂对原料的适应性以及不同级配方式的加氢脱硫、脱氮效果。系统总结了原料、反应条件等对催化剂类型及其级配方式的影响,并建立了能够比较全面反映原料性质、反应条件和催化反应路径等对柴油超深度加氢脱硫反应影响的综合性的动力学模型。动力学模型计算结果表明,采用W-Mo-Ni/Mo-Co级配催化剂体系能够合理利用加氢反应器内不同区域反应条件的差异,达到更好的反应效果,并得到了工业应用结果的支持。     

柴油加氢脱硫反应路径影响机理研究进展

文章主要介绍了柴油馏分中难脱除的二苯并噻吩类（DBTs）硫化物存在的加氢脱硫反应路径,其中DDS和HYD是目前研究较多的主要反应路径。总结了催化剂活性助金属、硫化氢、氮化物以及氢分压对加氢脱硫反应路径选择性的影响并探究其影响机理。     

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.     

镁基固体催化剂催化酯交换反应制备生物柴油研究进展

生物柴油是一种重要的可再生能源,非均相催化甘油酯酯交换反应制备生物柴油是当前的研究热点,而高活性的非均相催化剂则是非均相催化工艺的核心。镁基催化剂由于其原料来源广泛、价格低廉,受到了广泛关注。综述近年来镁基催化剂催化酯交换反应制备生物柴油的研究进展,重点介绍了镁基催化剂制备方法、组成、结构、反应条件等对催化酯交换反应活性的影响,并探讨了镁基催化剂目前存在的不足以及今后的发展方向。     

催化柴油管式液相加氢反应动力学模型

针对国内某石化公司提出的催化柴油管式液相加氢新工艺,在压力为6.5 MPa,温度为623.15 K,进口混氢量为0.42%(质量分数)的条件下,以RS-2000为催化剂进行了初步小试实验研究。根据实验结果建立了催化柴油管式液相加氢反应动力学模型,主要包括脱硫(HDS)、脱氮(HDN)和芳烃加氢饱和反应的动力学模型以及氢耗方程。用MATLAB软件求解模型参数并将模型计算结果与实验值进行比较,两者吻合良好。最后用所建模型预测了该实验条件下的多点补氢过程,结果表明,补氢点数以及每点补氢量的多少对反应结果都有很大影响,可为新工艺的进一步研究提供参考。     

Deep hydrodesulphurization and hydrogenation of diesel fuels on alumina-supported and bulk molybdenum carbide catalysts

Deep hydrodesulphurization (HDS) of diesel fuels has been carried out on P (Ni)-promoted or non-promoted Mo₂C-supported γ-Al₂O₃ and bulk Mo₂C under standard industrial conditions (613 K, 3 MPa). The effect of the promoter was investigated for different feedstocks on HDS and hydrogenation (HYD) with very low levels of sulfur. The temperature effect was also followed. The HDS conversion indicates that phosphorus promoted alumina supported carbide catalysts are as active as a commercial Co-Mo/Al₂O₃ catalyst for low levels of sulfur in the feed. Furthermore, the refractory compounds such as 4,6-dimethyldibenzothiophene are only transformed on molybdenum carbide catalyst in industrial conditions for hydrotreated gas oils. With gas oils with less than 50 wt ppm in sulfur, phosphorus promoted molybdenum carbide catalysts become more active than commercial catalysts for the HYD of the aromatic compounds and the HDS or the HDN of the feedstock.     

V-Mo based catalysts for oxidative desulfurization of diesel fuel

Catalytic oxidative desulfurization (ODS) of a Mexican diesel fuel on a spent HDS catalyst, deactivated by metal deposits, was carried out during several reactive-batch cycles in order to study the catalytic performance to obtain low sulfur diesel. To explain catalytic activity results, Mo and/or V oxides supported on alumina pellets were prepared and evaluated in the ODS of a model diesel using tert-butyl hydroperoxide (TBHP) or H₂O₂ as oxidant. The catalytic results show that V-Mo based catalysts are more active during several ODS cycles using TBHP. The performance of the catalysts was discussed in terms of reduced species of vanadium oxide, prevailing on the catalysts, which increase the sulfone yield of refractory HDS compounds (DBT, 4-MDBT and 4,6-DMDBT).     

油品深度加氢脱硫催化研究进展

汽油深度脱硫的关键是在脱硫同时避免辛烷值的下降和汽油收率的损失;柴油深度脱硫的关键是对反应活性最低的4,6-二甲基苯并噻吩类化合物中硫原子的脱除,并克服原料中多环芳烃和含氮物以及产物中H2S对脱硫效果的抑制作用.本文概述了汽油和柴油深度脱硫催化剂在工业应用方面的研究进展,综述了加氢脱硫催化剂基础研究方面的最新动态;强调了在分子和原子水平上认识加氢脱硫催化剂微观结构和反应机理对研发超高活性及选择性深度脱硫催化剂的指导作用.     

An overview of new approaches to deep desulfurization for ultra-clean gasoline, diesel fuel and jet fuel

This review discusses the problems of sulfur reduction in highway and non-road fuels and presents an overview of new approaches and emerging technologies for ultra-deep desulfurization of refinery streams for ultra-clean (ultra-low-sulfur) gasoline, diesel fuels and jet fuels. The issues of gasoline and diesel deep desulfurization are becoming more serious because the crude oils refined in the US are getting higher in sulfur contents and heavier in density, while the regulated sulfur limits are becoming lower and lower. Current gasoline desulfurization problem is dominated by the issues of sulfur removal from FCC naphtha, which contributes about 35% of gasoline pool but over 90% of sulfur in gasoline. Deep reduction of gasoline sulfur (from 330 to 30 ppm) must be made without decreasing octane number or losing gasoline yield. The problem is complicated by the high olefins contents of FCC naphtha which contributes to octane number enhancement but can be saturated under HDS conditions. Deep reduction of diesel sulfur (from 500 to <15 ppm sulfur) is dictated largely by 4,6-dimethyldibenzothiophene, which represents the least reactive sulfur compounds that have substitutions on both 4- and 6-positions. The deep HDS problem of diesel streams is exacerbated by the inhibiting effects of co-existing polyaromatics and nitrogen compounds in the feed as well as H₂S in the product. The approaches to deep desulfurization include catalysts and process developments for hydrodesulfurization (HDS), and adsorbents or reagents and methods for non-HDS-type processing schemes. The needs for dearomatization of diesel and jet fuels are also discussed along with some approaches. Overall, new and more effective approaches and continuing catalysis and processing research are needed for producing affordable ultra-clean (ultra-low-sulfur and low-aromatics) transportation fuels and non-road fuels, because meeting the new government sulfur regulations in 2006–2010 (15 ppm sulfur in highway diesel fuels by 2006 and non-road diesel fuels by 2010; 30 ppm sulfur in gasoline by 2006) is only a milestone. Desulfurization research should also take into consideration of the fuel-cell fuel processing needs, which will have a more stringent requirement on desulfurization (e.g., <1 ppm sulfur) than IC engines. The society at large is stepping on the road to zero sulfur fuel, so researchers should begin with the end in mind and try to develop long-term solutions.     

Control of hydrodesulfurization and hydrodearomatization properties over bimetallic Pd-Pt catalysts supported on Yb-modifed USY zeolite

Increasingly stringent regulations on the removal of aromatic and sulfur compounds in diesel fuel require the development of new catalysts and processes. Here, control of hydrodesulfurization (HDS) and hydrodearomatization (HDA) properties was studied by preparing bimetallic Pd-Pt catalysts supported on ytterbium-modified ultrastable Y (USY) zeolite by impregnation and subsequent calcination under different temperatures. Catalytic performances of the prepared catalysts, such as HDS of 4,6-dimethyldibenzothiophene (4,6-DMDBT) and HDA of tetralin, were investigated in a high-pressure continuous-flow reactor. With changing calcination temperature, the HDS activity is only slightly affected, although the maximum HDS conversion was obtained at 300°C. In contrast, the HDA activity decreased significantly, with hydrogenation selectivity remaining relatively constant as confirmed by the weak variation of the trans-decalin to cis-decalin ratio. A low calcination temperature of 200°C simultaneously favored both deep HDS and deep HDA, whereas a high calcination temperature of 500°C favored selective HDS reactions with minimal HDA reactions (i.e. saving of expensive hydrogen). These results clearly indicate that the selectivity of HDS to HDA can be controlled by simply changing the calcination temperature of Pd-Pt/Yb/USY zeolite catalysts.     

TiO2-SiO2复合氧化物的理化性质及其对柴油加氢精制性能的影响

采用溶胶-凝胶法结合CO₂超临界流体干燥技术制备了不同Ti/Si原子比的TiO₂-SiO₂复合氧化物（TS-n）,考察了Ti/Si原子比、焙烧温度对复合氧化物比表面积、孔结构、酸性及原子结合状态的影响,通过重油催化裂化柴油加氢精制反应考察了以TS-1、TS-4为载体的催化剂脱硫性能的差异.结果表明,TiO2经SiO2复合改性后,热稳定性和晶态稳定性大幅度提高;TiO₂-SiO₂复合氧化物的酸性及原子间的相互作用与Ti/Si原子比有直接的关系;载体的晶态组成及酸性和催化剂的酸性对催化剂的加氢脱硫性能有显著影响,复合氧化物中锐态型TiO₂的存在强化了载体与金属组分之间的相互作用,提高了催化剂的加氢脱硫活性,不同类型的酸性中心对柴油中不同类型的硫化物具有不同的脱除能力,Bronsted 酸中心较多的催化剂对结构简单的硫化物脱除能力强,Lewis酸中心较多的催化剂对结构复杂的硫化物有较好的脱除效果.     

Comprehensive two-dimensional gas chromatography for basic and neutral nitrogen speciation in middle distillates

The molecular knowledge of nitrogen compounds in diesel feedstocks has become a key issue in the development of hydrotreatment processes, especially for ultra-low sulfur diesel production. Indeed, nitrogen species have a strong impact on the hydrodesulfurization (HDS) pathway, since basic nitrogen is known to poison acidic sites of HDS catalysts.Since conventional methods only allow a poor degree of information, the increased separation power of comprehensive two-dimensional gas chromatography (GC × GC-NCD) was used in this study to obtain a detailed overview of nitrogen compounds by type (basic/neutral), by family and by carbon breakdown in diesel and liquefied coal samples. Partially hydrogenated compounds such as tetrahydrocarbazole and tetrahydroquinoline derivatives could even be detected in liquefied coal samples as well as diesel from ebullated bed conversion units. Comparison of GC-NCD with GC × GC-NCD for quantitative determination of nitrogen compounds by family was achieved in a first step. These results demonstrate the superiority of GC × GC to allow for a comprehensive characterization of nitrogen compounds in diesel and related samples in one injection. Furthermore, nitrogen speciation by GC × GC-NCD technique allows identifying most nitrogen species in conventional diesel or liquefied coal samples, with no use of mass spectrometry.GC × GC-NCD was also applied to a wide range of diesel feedstocks obtained from distillation, cokefaction, FCC, ebullated bed hydroconversion units to correlate nitrogen species to the origin of the feedstocks or distillation end points, giving interesting indications on reaction mechanisms involved in the processes.     

有机含氮化合物对深度加氢脱硫反应的影响

从燃料油中含氮化合物和含硫化合物特点出发,介绍了含氮化合物对加氢脱硫（HDS）催化剂活性、选择性以及失活等性能的影响。研究表明,含氮化合物主要通过与含硫化合物在催化剂表面的竞争吸附,强烈抑制HDS催化剂活性。含氮化合物对含硫化合物加氢（HYD）和氢解（HYG）两条并行反应路径均有抑制作用,但对HYD反应路径的抑制作用更为强烈。含氮化合物还能通过毒化催化剂酸中心进而影响催化剂HDS活性和选择性,而其在催化剂表面的强烈吸附也是引发催化剂结焦和失活的重要因素。     

Oxidative Desulfurization of Hydrocarbon Fuels

New requirements for very low sulfur content (10 ppm) in liquid motor fuels demand novel approaches for ultra-deep desulfurization. For production of near-zero-sulfur diesel and low-sulfur fuel oil, removal of refractory sulfur compounds, like 4,6-dimethyldibenzothiophene and other alkyl-substituted thiophene derivatives, is necessary. Elimination of these compounds by hydrodesulfurization (HDS) requires high hydrogen consumption, high pressure equipment, and new catalysts. Various oxidative desulfurization processes, including recent advances in this field for diesel fuels, and the drawbacks of this technology in comparison with HDS are examined and discussed. It is shown that the oxidation of sulfur compounds to sulfones with hydrogen peroxide allows for production of diesel fuels with a sulfur content of 10 ppmw or lower at atmospheric pressure and room temperature. The gas phase oxidative desulfurization of sulfur compounds with air or oxygen is feasible at atmospheric pressure and higher temperatures: 90–300 °С and offers better economic solutions and incentives.     

Deep desulfurization of full range and low boiling diesel streams from Kuwait Lower Fars heavy crude

Information on feed quality and, in particular, various types of sulfur compounds present in the diesel (gas oil) fractions produced form different crudes and their HDS reactivities under different operating conditions are of a great value for the optimization and economics of the deep HDS process. This paper deals with deep desulfurization of gas oils obtained from a new heavy Kuwaiti crude, namely, Lower Fars (LF) which will be processed in the future at Kuwaiti refineries. Comparative studies were carried out to examine the extent of deep HDS, and the quality of diesel product using two gas oil feeds with different boiling ranges. The results revealed that the full range diesel feed stream produced from the LF crude was very difficult to desulfurize due to its low quality caused by high aromatics content (low feed saturation) together with the presence of high concentrations of organic nitrogen compounds and sterically hindered alkyl DBTs. The low-boiling range gas oil showed better desulfurization compared with the full range gas oil, however, deep desulfurization to 50 ppm sulfur was not achieved even at a temperature as high as 380 °C for both feeds. The desulfurized diesel product from the low-boiling gas-oil feed was better in quality with respect to the S, N and PNA contents and cetane index than the full-range gas-oil feed.