孔结构优化对渣油加氢脱金属剂的影响研究

介绍了孔结构优化对渣油加氢脱金属剂的影响。为提高脱金属剂的脱金属活性以及长周期运行稳定性,首先以工业参比失活脱金属剂的失活行为做指导,提出自制脱金属剂设计优化思路;随后在脱金属剂载体制备过程中,加入薄膜胶溶剂和高聚合度扩孔剂并调节水含量成功制备出具有更多大孔分布、更大孔容的载体。与工业参比脱金属剂相比,自制脱金属剂载体具有更多的300 nm孔分布,孔容提高约50%。自制脱金属剂对镍、钒总脱除能力比工业参比脱金属剂高2%~3%,并具有优异的长周期运转稳定性。自制脱金属剂有着更好的渣油加氢反应性能和稳定性,有较好的应用前景。     

中低温煤焦油加氢过程中沥青质组成与性质

以中低温煤焦油为原料,采用小型固定床连续加氢反应装置进行2 500 h全馏分加氢实验,研究煤焦油加氢沥青质组成与性质随加氢反应器运行时间延长的变化规律。结果表明:随反应时间的延长,催化剂活性逐渐降低,煤焦油沥青质脱除率降低,加氢沥青质S和N杂原子含量以及Fe和Ca金属含量均增加,脱除率均降低,在一定温度范围内,提高反应温度可以提高煤焦油沥青质加氢转化性能,但也促进大分子量的沥青质生成;此外,随反应时间的延长,加氢沥青质芳香度(f_A)增大,H和C原子比降低,说明加氢沥青质缩合度提高,另外,加氢沥青质分子量逐渐增大,甚至超过原生沥青质,说明部分沥青质发生缩聚反应;反应后期,沥青质缩聚反应加剧,金属Fe和Ca易沉积在催化剂上,催化剂失活严重。     

渣油加氢催化剂金属沉积的研究进展

随着原油日益变重,渣油加氢技术在炼油工业中得以迅速发展。分析渣油中金属存在形式及其结构特点,论述金属在催化剂上的沉积形式及其分布,讨论渣油性质、工艺条件以及催化剂性质对金属沉积的影响。通过讨论与分析,指出金属沉积物是渣油加氢催化剂失活的主要原因,但对金属在催化剂上的沉积机理以及沉积物形式存在争议。胶质与沥青质中金属含量较高,在加氢脱金属过程中,渣油中沥青质和胶质含量以及结构变化对于催化剂上金属沉积的影响有待研究。反应温度和反应压力对金属沉积规律的影响也需要进一步深入研究,尤其是H₂（H₂S）在脱金属反应过程中的作用机理。     

柴油催化加氢脱芳烃研究进展

论述了柴油加氢脱芳烃的催化剂体系、芳烃加氢反应机理和工艺方法。该催化剂体系包括贵金属催化剂和非贵金属催化剂两种类型,其中贵金属催化剂的脱芳烃效果较非贵金属催化剂要好。柴油加氢脱芳烃大多采用两段加氢工艺,将贵金属和非贵金属催化剂结合使用可以取得良好的脱芳烃效果。增强脱芳烃催化剂的抗硫性能也成为现今研究重点,载体的性质对加氢脱芳烃催化剂的催化性能有很大的影响,开发新载体和新材料成为今后加氢脱芳烃催化剂的研究趋势。     

Modeling residue hydrotreating

In this paper a kinetic model for the residue hydrotreating is presented. The model considers kinetics, adsorption and diffusion inside the hydrodemetallization catalyst pellets. The diffusion is described by the Stefan–Maxwell equations extended for starkly different sized molecules, due to molecular size of residue molecules large distribution. Effective diffusion coefficients vary with porosity and tortuosity evolution due to volume constraints in the catalyst pellets. The model's kinetic and thermodynamic parameters were estimated from a set of experiments carried out in a batch reactor with a Middle East vacuum residue. A comparison between experimental and simulated metal profiles inside the catalyst exhibit the slow diffusion, validating the importance of adding mass transfer phenomena and considering volume constraints even in a macroporous demetallization catalyst.The model was validated by other tests performed in the same reactor using the same vacuum residue, but with different catalysts. The differences in the catalyst pore size allowed to predict all the hydrotreatment yields, showing diffusion is a crucial factor.     

煤焦油加氢精制和加氢裂化催化剂的研究进展

阐述了催化剂中活性金属和助剂的种类及含量对催化剂性能的影响;总结了活性金属和助剂对金属-载体相互作用、催化剂酸分布以及催化剂表面性质的影响机制。指出制备一个性能优良的催化剂应从两方面入手,首先是制备一个性能优良的载体,要求它具有合适的孔分布和酸分布, 负载的金属应具有较高的分散度和还原性能。探讨了适于煤焦油的加氢处理催化剂,主要是防止催化剂的中毒、积炭、失活,并且协调各种催化剂同步失活,以利于整个装置运行周期的延长。旨在为煤焦油加氢精制和加氢裂化催化剂研究（设计）提供一定的理论指导,避免焦油加氢精制和加氢裂化催化剂研究和开发的盲目性。     

Alumina-silica binary mixed oxide used as support of catalysts for hydrotreating of Maya heavy crude

Alumina-silica binary mixed oxide support is used to prepare catalysts for hydrotreating of Maya heavy crude. Support is prepared by urea hydrolysis. Sequential incipient wetness and co-impregnation techniques are employed for preparation of catalysts. Ammonium heptamolybdenum is used as precursor of MoO₃. Catalysts are characterized by X-ray diffraction (XRD), temperature-programmed reduction (TPR) and the pore size distribution. Hydrodemetallation (HDM), hydrodesulfurization (HDS), hydrodenitrogenation (HDN), and asphaltene conversion (HDAsp) reactions are studied on these catalysts. One reference catalyst is also taken for comparison. Coke and metals depositions on spent catalysts are measured. The catalyst deactivation rate is also studied. The X-ray diffraction (XRD) results reveal that molybdenum atoms are well dispersed into CoMo catalyst, whereas MoO₃ crystalline phases are found in PCoMo and PNiMo catalysts. TPR reduction profiles are different for different catalysts. The laboratory made catalyst is reduced at one temperature, whereas the reference catalyst shows two reduction profiles. The reference catalyst shows the highest activities among four catalysts. The highest HDM and HDAsp activities of the reference catalyst may be due to its bigger pore diameter. The presence of TiO₂ in the reference catalyst enhances HDS and HDN activities. The CoMo catalyst shows higher activities than those of PCoMo and PNiMo catalysts. The presence of crystalline MoO₃ causes for lower activities of catalysts PCoMo and PNiMo.     

Catalytic hydrotreatment of heavy liquids prepared from coals of different rank

Heavy liquids prepared from a bituminous, a sub-bituminous and a brown coal were hydrotreated with commercial and titania-supported nickel-molybdenum catalysts to examine the reactivity and selectivity of the catalysis in relation to catalyst structure and catalytic functions. Liquids from the sub-bituminous and the brown coals behaved very similarly in the depolymerization scheme of conversion from preasphaltene to asphaltene, where the titania-supported catalysts exhibited preferential activity for the preasphaltene fraction with only limited conversion of the asphaltene fraction. The commercial catalyst showed no preferential selectivity in spite of the similar reaction scheme. Preasphaltene from the bituminous coal behaved in a contrasting manner on both catalysts, requiring the ring-opening reaction as deduced from the structural analyses in the same conversion without any preference for asphaltene. The effect of solvent composition was examined in some tests in order to improve conversion.     

Development and application of ex-situ presulfurization technology for hydrotreating catalysts in China

The development and application of ex-situ presulfurization (EPRES) technology for hydrotreating catalysts has been reviewed in the present article. The studies in laboratory scale and commercial practice indicated that the adoption of the EPRES catalyst in industrial application can significantly enhance the degree of presulfurization of metal oxide components, shorten the start-up period, and effectively reduce the environmental impact as well as the danger of start-up procedure in industrial hydrotreating unit. This catalyst has been proved to be versatile for different types of hydrogenation reactions. Different types of active site models are also discussed for better understanding the nature of presulfurized catalysts.     

俄罗斯渣油加氢处理技术开发与工业应用

俄罗斯是我国最大原油供应国之一,俄罗斯渣油中硫、氮、残炭、金属含量均较高,无法直接进入催化裂化装置加工,需要进行渣油加氢处理。本文利用核磁、傅里叶变换高分辨质谱等技术手段对俄罗斯渣油分子结构进行了详细表征,并根据其性质和分子结构特点,对PHR系列催化剂及级配进行适应性优化改进,开发形成了俄罗斯渣油加氢处理技术。工业应用结果表明,开发的俄罗斯渣油加氢处理技术具有非常出色的原料适应性和活性稳定性,能够实现俄罗斯渣油中S、N、Ni、V深度脱除和残炭深度转化,催化剂运行时间达到19416h,1t催化剂加工处理原料油达到6000t,均比设计值高62%。通过分析加氢渣油中未被脱除的氮化物分子形态,提出了实现技术持续优化改进的方向。     

Cracking behavior of asphaltene in the presence of iron catalysts supported on mesoporous molecular sieve with different pore diameters

Cracking of a mixture of petroleum asphaltene and 10 wt% Fe catalyst supported on mesoporous molecular sieve (SBA-15) possessing a hexagonal array of uniform mesopores has been studied with a fixed bed reactor at 573 K under atmospheric He. When average pore diameter of Fe/SBA-15 is varied between 4.5 and 15 nm, asphaltene conversion increases almost linearly with increasing pore diameter up to 12 nm and reaches 65%, though the increment is small beyond this value. On the other hand, yield of maltene formed is almost independent of the diameter and less than 15% but greatly improved by using pressurized H₂ in place of He. Although pore volumes of all Fe/SBA-15 catalysts decrease by mixing with feed asphaltene, the extent of the decrease is larger for the catalyst with a larger pore diameter, which shows that higher asphaltene conversion may arise from the presence of larger amounts of asphaltene molecules held inside the larger mesopores. The N₂ adsorption measurements reveal that pore structures of Fe/SBA-15 catalysts are almost unchanged after cracking and subsequent re-calcination to remove deposited coke. The X-ray diffraction analysis and temperature programmed oxidation after cracking suggest that Fe species are highly dispersed inside the mesopores and present as the sulfided phases at the outermost layer.     

渣油中沥青质的存在形态及其加氢转化反应

沥青质是渣油的重要组成部分,是渣油加氢反应过程中的转化难点。文章在叙述沥青质化学结构表征方法的基础上,讨论了沥青质的结构组成及其在渣油中的存在形态,并对渣油加氢转化反应过程中沥青质的转化行为和反应机理进行了论述。     

Hydrogenation of brown coal. 3. Roles of hydrogen and hydrogen-donor solvents in systems catalysed by iron and tin compounds

The role of hydrogen and hydrogen-donor solvents in the liquefaction of a Victorian brown coal without added catalyst and in the presence of iron-and tin-based catalysts has been studied. Results of an investigation of the effect of temperature and pressure on the conversion parameters, of independent studies of asphaltene hydrogenation, and of work with model ethers are described. A mechanism is tentatively proposed to describe the role of iron, tin and iron-tin catalyst systems based upon these results.     

有机配体对加氢处理催化剂的影响进展

简述了近些年来有机配体对加氢处理催化剂的影响研究情况。添加有机配体可以提高加氢处理催化剂活性,从有机配体对加氢处理催化剂的制备及硫化过程的影响角度对文献的研究结果进行了综述,并对有机配体的作用机理进行了分析讨论。文中总结指出,有机配体与活性金属、载体的作用改变了金属与载体的相互作用,影响了金属组分的分散和硫化,从而有利于高活性CoMoS相的生成。     

Effect of phosphorus on activity of hydrotreating catalyst of Maya heavy crude

The effect of phosphorus on physical properties of the catalyst and on activity of hydrotreating of Maya crude was studied in this work. Catalysts were prepared by the co-impregnation method. Alumina-titania binary oxide was used as a support material. The presence of phosphorus in the catalyst decreases the percentage of micropores, and it results in a decrease of specific surface area. Temperature program reduction (TPR) shows that phosphates reduce metal support interaction. It leads to the formation of polymolybdate phases in expense of strongly bonded tetrahedral molybdates. At higher P loading, polymolybdates may be present with quasi crystalline MoO₃. However, the TPR experiment is not sufficiently sensitive to distinguish several phases present on the catalysts used by the authors. A slight increment of HDM activity is observed, but HDS activity is lower in the P containing catalyst compared with the P free catalyst. The changes of physical properties of the spent catalysts are mainly due to the coke formation on the catalyst. The presence of phosphorus on hydrotreating catalysts inhibits coke formation during the hydrotreating reaction.     

FF-46再生催化剂在航煤加氢装置中的应用

FF-46是抚顺石油化工研究院开发的高活性加氢处理催化剂,该催化剂具有较高的脱硫、脱氮活性,工业运转后的催化剂经再生后同样具有较好的活性。主要介绍FF-46再生催化剂在扬子石化航煤加氢装置的使用情况。从催化剂选型、装填、活化、航煤初期生产情况、经济效益等几个方面做出了分析,证明FF-46再生催化剂可用于航煤加氢装置,在航煤产品质量达到国标要求的前提下,既使FF-46再生催化剂得到充分合理利用,又大幅度节省新催化剂采购费用,并拓宽了加氢裂化预处理催化剂再生后的使用范围。     

首套南疆渣油加氢装置长周期运行难点及对策

该套渣油加氢装置为首套加工南疆油的渣油加氢装置,由于南疆油中难溶沥青质含量较高,其转化率较低,装置分馏系统低温部位易出现沥青质析出积垢,精制渣油外输压降增大,导致该装置被迫降负荷生产,换热器结垢后精制渣油与原料油换热器换热效果下降,反应加热炉入口温度下降,增加了反应加热炉的负荷,直接影响装置长周期运行,通过各种措施的有效实施,装置运行周期得到延长。     

延迟焦化脱金属剂的开发与应用

针对辽河超稠油金属含量高,残炭、胶质、沥青质含量高的特点,研究开发了焦化脱金属剂。主要介绍了焦化脱金属剂的特点和试验室评价、工业试验及现场应用情况。     

Deactivation of hydrodesulfurization catalysts by metals deposition

Primary causes of deactivation of hydrodesulfurization catalysts are partial poisoning of the interior pore surface and pore-mouth plugging by deposition of metals from organo-metallic compounds in the reactor feed. A model is developed to account for both causes of deactivation. It can be used to predict which occurs first: complete surface poisoning or pore-mouth plugging. Equations are formulated for catalyst activity as a function of time for demetallization and also for desulfurization. The results depend upon particle geometry and geometry of deposited species, Thiele moduli for demetallization and desulfurization, and relative rates of desulfurization on fresh and partially poisoned catalytic surfaces. The treatment is for a single, isothermal catalyst particle.     

Study of accelerated deactivation of hydrotreating catalysts by vanadium impregnation method

The main causes of catalysts deactivation for hydrotreating are coking and metals deposition. In this present work, accelerated deactivation of hydrotreating catalysts was studied. In this respect, vanadium which is deposited with nickel during hydrotreating reaction was impregnated into the fresh hydrotreating catalyst. Different percentage of vanadium was impregnated and their hydrodemetalization (HDM) and hydrodesulfurization (HDS) activities were studied in bench-scale reactor of heavy crude oil. Accelerated deactivations for both HDM and HDS were observed on vanadium impregnated catalysts. The rate of HDS deactivation was faster than that of HDM reaction. The rapid deactivation of HDS may be due to the coverage of active sites by impregnated vanadium atom. The deactivation is slower when the V loading is low; but above 10 wt% loading a rapid deactivation is observed. A comparison of deactivation is made in between normal deactivation and the deactivation by vanadium impregnation. It was found that deactivation by vanadium impregnation is lower than that of normal deactivation. It suggests that at initial stage the formation of coke causes deactivation of the catalyst whereas at later stage when metals sulfides deposition is quite high, these sulfides take part in deactivation.