Hydrocracking of Gudao Residual Oil with Dispersed Catalysts Using Supercritical Water-Syngas as a Hydrogen Source. Part II: The Comparison of Residue Hydrocracking in Different Hydrogen Sources

Different catalytical hydrogen sources were compared with molecular hydrogen gas in the hydrocracking of Gudao residue in the presence of catalysts (PMA). The results showed that alternative hydrogen sources were effective in catalytic hydroconversion of heavy oil. The hydroconversion of residue in supercritical water-syngas system showed similar results when performed with molecular hydrogen.     

Hydrocracking of Gudao Residual Oil with Dispersed Catalysts Using Supercritical Water-Syngas as a Hydrogen Source

Abstract:

Heavy oil upgrading is a very important process in the petroleum industry, but is very difficult because it has a high impurity content. A variety of heavy oil upgrading technologies have been developed in the world, including the catalytic hydrocracking process, which can process various heavy oils with a high yield of liquid products. Although this technology is one of the most widely used methods for upgrading heavy oil, the use of expensive molecular hydrogen is costly. The heavy oil upgrading technology with alternative hydrogen is very important. The catalytic hydroconversion of Gudao residue with different catalysts using water-syngas as an alternative hydrogen was investigated in this study. Hydrogen is provided in-situ for hydrocracking through the water-gas shift reaction (WGSR). The experimental results show that catalysts play a very important role in catalytic hydroconversion of Gudao residue using water-syngas as an alternative hydrogen. Addition of catalysts to residue was found to improve the distribution or properties of cracking products and inhibit the asphaltene or TI formation.     

Hydrocracking Gudao Residual Oil Using Supercritical Water-Syngas as Hydrogen Source in Suspension Bed. Part III: Water-Gas Shift Reaction

Abstract

The catalytic hydroconversion of Gudao residue in supercritical water-syngas system is a heavy oil upgrading technology. The hydrogen derived from water-gas shift reaction can be used for residue hydrocracking, so, it is important for studying the water-gas shift reaction that takes place in the hydrocracking system. Here, the water-gas shift reaction in the supercritical water-syngas system was investigated. The results showed that the water-gas shift reaction could be effectively increased with dispersed catalysts, and more than 80% CO was conversed in the initial processes.     

Hydrocracking of Gudao Residual Oil with Dispersed Catalysts Using Supercritical Water-Syngas as a Hydrogen Source

Heavy oil upgrading is a very important process in the petroleum industry, but is very difficult because it has a high impurity content. A variety of heavy oil upgrading technologies have been developed in the world, including the catalytic hydrocracking process, which can process various heavy oils with a high yield of liquid products. Although this technology is one of the most widely used methods for upgrading heavy oil, the use of expensive molecular hydrogen is costly. The heavy oil upgrading technology with alternative hydrogen is very important. The catalytic hydroconversion of Gudao residue with different catalysts using water-syngas as an alternative hydrogen was investigated in this study. Hydrogen is provided in-situ for hydrocracking through the water-gas shift reaction (WGSR). The experimental results show that catalysts play a very important role in catalytic hydroconversion of Gudao residue using water-syngas as an alternative hydrogen. Addition of catalysts to residue was found to improve the distribution or properties of cracking products and inhibit the asphaltene or TI formation.     

孤岛减压渣油在CO-SCW体系中催化加氢

对孤岛减压渣油在CO -SCW体系中加氢改质研究表明 ,利用CO与SCW发生的水 -气变换反应获得加氢所需氢源是可行的。在适宜的条件下 ,渣油在CO -SCW体系中改质可达到在H2 -SCW体系中改质同样的效果     

A study of structural transformations of asphaltene molecules during hydroconversion of vacuum residue at various temperatures in the presence of nanosized molybdenum disulfide particles

Elemental analysis, molecular mass, and ¹H NMR data are presented for vacuum residue asphaltenes and the products of vacuum residue hydroconversion in the presence of nanosized MoS₂ catalyst particles obtained “in situ” in the hydrocarbon medium. Structural group analysis of average asphaltene molecules has been performed and their structural units have been described. The main trends of change in the structural parameters of the molecules under the hydroconversion conditions and the effect of temperature on the character of these changes have been revealed.     

催化裂化柴油加工转化过程的经济性分析

立足柴油组分的分子结构，通过分析各类柴油原料和其加氢产品的组成关系，研究柴油组分加氢精制过程中的芳烃饱和反应规律，以及不同加氢深度对催化裂化柴油（简称LCO）回炼时裂化转化结果的影响，从经济性角度探讨LCO的不同加工路线。结果表明：LCO加氢精制生产国Ⅵ标准柴油的过程中，芳烃加氢饱和反应的耗氢量占反应总耗氢量的50%左右；LCO因其密度大、多环芳烃含量高，作为国Ⅵ车用柴油调合组分时需要深度加氢饱和芳烃，因而耗氢成本巨大，经济性极差；LCO选择性加氢-催化裂化组合（LTAG）工艺，LCO的加氢反应深度降低，耗氢成本大幅降低；可利用加氢转化制汽油、加氢转化制芳烃、加氢裂化混合掺炼、渣油加氢和催化裂化组合回炼等技术，实现富含芳烃的LCO资源的高效利用。     

EFFECT OF PREHYDROGENATION ON HYDROCONVERSION OF MAYA RESIDUUM,PART II: HYDROGEN INCORPORATION

ABSTRACT

Maya 650° F residuum (Maya AR) was prehydrogenated over a standard hydroprocessing catalyst. The 650°F residuum of this product lpar;HMaya ARrpar; and Maya AR were then separately hydroprocessed further at selected conditions. The products were examined by elemental, ¹H, and ¹³C NMR analyses to determine the how hydrogen was incorporated during processing.

For all processing steps, hydrogen was incorporated in capping fragments formed during cracking reactions, as well as in hydrogenation reactions, heteroatom removal, and hydrocarbon gas formation, but the distribution of the hydrogen was dependent upon the type and severity of the process: For the direct hydroconversion of Maya AR, 25 to 30% of the total hydrogen was incorporated for heteroatom removal and hydrocarbon gas formation. The remaining hydrogen was incorporated in hydrogenation and cracking reactions.

For the two-step hydroconversion process, 30 to 40% of the total hydrogen was incorporated for heteroatom removal and hydrocarbon gas formation. The remaining was primarily incorporated in hydrogenation reactions. Some was incorporated into cracking reactions in the moderate severity case, but almost none was seen in the low severity case.

The hydrogen incorporation during each specific processing step is discussed, along with an evaluation of the prehydrogenation step a residuum conversion process option. These results will be also compared to previously reported hydrogen incorporation measurements on other feeds and processing methods.     

Infrared Study of Hydrogen Bond Types in Asphaltenes

Abstract

The structural characteristics of asphaltenes are important to refiners for determining the yields from the residual fraction of crude oils and the operating parameters of the process units for deep conversion processes. In this article, we studied the hydrogen bonding distribution of four Saudi Arabian crude-oil-derived asphaltenes against the phenol solutions of various concentrations in carbon tetrachloride. In an attempt to explain relative hydrogen bonding capabilities of asphaltenes, OH peak intensity of phenol and enthalpies of hydrogen bond formation were used in combination with the content of heteroatoms (N, O, and S) in asphaltenes. The OH peak intensity of phenol depends on the presence of acidic and basic moieties or functional groups on the surface of asphaltenes. The results obtained show that the asphaltenes with high oxygen and low nitrogen contents have poor interaction with phenol, which indicates that oxygen might be incorporated as acidic hydroxyl groups in asphaltenes. In a similar way, asphaltenes with low oxygen and high nitrogen contents give high phenol interaction values. Piperidine was also tried to evaluate the hydrogen bonding capabilities of NH group with the asphaltenes. The trace metal and GPC molecular weight measurements showed that the Arab heavy asphaltenes possess highest molecular weights and maximum V and Ni contents.     

Kinetic Study on the Hydrocracking Reaction of Vacuum Residue Using a Lumping Model

Abstract

Based on the experimental hydrocracking of vacuum residue, a kinetic study using a lumping model was carried out to gain insight into the characteristics of catalytic reactions. The lumped species were the saturates, aromatics, resins, and asphaltenes (SARA) constituents in the residue (798 K⁺) fraction and gas, naphtha, kerosene, gas oil, vacuum gas oil, and coke in the products. The pyrite reaction favoring hydrocracking to lighter products was more temperature-dependent than that using a mixture of pyrite and active carbon. The kinetic study showed that the addition of active carbon to pyrite limited the transformation of resins to asphaltenes.     

Thermal Hydrocracking Kinetics of Chinese Gudao Vacuum Residue

Abstract

The thermal hydrocracking kinetics of Chinese Gudao vacuum residue was studied in a batch autoclave reactor. The temperature ranged in 390–435°C and the initial hydrogen pressure was 7.0 MPa at 20°C. Ammonium phosphomolybdate (APM) in its dispersed phase was the catalyst. The reaction products, gas, naphtha, atmospheric gas oil (AGO), vacuum gas oil (VGO) and coke, were separated during and after experiments, and their yields vs. reaction time were obtained, for four reaction temperatures: 390, 405, 420, and 435°C. The activation energy was calculated from a traditional kinetic model to be 218.6 kJ/mol. A new kinetic model was proposed in this work that allows for the calculation of activation energy with a minimum number of three tests, each at a different temperature. This is comparable to the traditional model which requires a minimum of 12 tests; a minimum of four tests for one temperature and a minimum of three temperatures. The activation energy calculated from the new model with four tests is 229.6 kJ/mol, only 5% greater than that obtained from the traditional model. The reaction rate constants obtained from this model are also consistent with those from the traditional model.     

全馏分高温煤焦油悬浮床加氢裂化中试试验

采用150 kg/d悬浮床加氢裂化中试装置,以全馏分高温煤焦油为原料,考察了反应温度、反应质量空速及反应压力对煤焦油加氢裂化反应性能及产物分布的影响。结果表明：升高反应温度和降低反应质量空速,均可以促进煤焦油中重油和沥青质的深度转化,气体和焦炭收率增加,重油收率降低,但过高的反应温度会降低轻油馏分收率;提高反应压力可以抑制气体和焦炭的生成,促进沥青质的加氢转化,保证了较高的轻油收率。在反应温度为465℃,反应压力为22 MPa,反应质量空速为0.5 h-1,氢气/原料油（体积质量比,L/kg）为1 500的最佳条件下,重油和沥青质的转化率分别达到26.05%和62.95%,轻油收率为77.42%,气体和焦炭收率为17.28%。     

Quantum-Chemical and Experimental Investigation of the Catalytic Activity of Nanosized Particles of Nickel-Promoted Molybdenum Disulfide in the Hydroconversion Process

The paper is devoted to the investigation of the catalytic properties of nickel-promoted molybdenum disulfide nanoparticles in the hydroconversion process. The formation of Mo and Ni compounds under hydroconversion conditions has been studied using chemical thermodynamics methods. Quantum-chemical calculations in the cluster approximation have confirmed the catalytic activity of Mo_nNi_mS_p nanoparticles in the reactions of hydrogen activation and aromatic-ring hydrogenation. It has been shown that the main role in the activation of hydrogen and the hydrogenation of aromatic rings is played by Mo- and Ni-containing active sites of the catalyst, respectively. To confirm theoretical assumptions, the yield of products of fuel oil hydroconversion on nanosized particles of the catalyst, nickel-promoted and in situ formed molybdenum disulfide, has been investigated. It has been shown that the promotion with nickel enhances the hydrogenating functions of the molybdenum-containing catalyst and lowers coke formation during hydroconversion.     

An Active Carbon Catalyst Prevents Coke Formation from Asphaltenes during the Hydrocracking of Vacuum Residue

Abstract

Active carbons were prepared by the steam activation of a brown coal char. The active carbon with mesopores showed greater adsorption selectivity for asphaltenes. The active carbon was effective at suppressing coke formation, even with the high hydrocracking conversion of vacuum residue. The analysis of the change in the composition of saturates, aromatics, resins, and asphaltenes in the cracked residue with conversion demonstrated the ability of active carbon to restrict the transformation of asphaltenes to coke. The active carbon that was richer in mesopores was presumably more effective at providing adsorption sites for the hydrocarbon free-radicals generated initially during thermal cracking to prevent them from coupling and polycondensing.     

塔河减压渣油浆态床加氢改质反应条件的考察

以塔河减压渣油为研究对象,通过高压釜反应模拟浆态床加氢反应过程,考察反应条件对塔河减压渣油加氢转化过程生焦率、转化率及产物分布的影响。结果表明,随反应温度的升高,渣油转化率及生焦随之增加;氢初压的提高对生焦有明显的抑制作用,起初渣油转化率随之降低,当超过8 MPa时略有增加;反应时间的增加对渣油转化率及生焦都有促进作用;催化剂的存在可以抑制生焦反应,同时在一定程度上也抑制了裂化反应,应控制适量。综合考虑,确定适宜的反应条件为：反应温度不宜高于430 ℃,氢初压7～8 MPa;反应时间40～60 min;催化剂的加入量2 000～6 000 mg/kg。     

Study of the Hydrogen Activation Reaction on Nanosized MoS<Subscript>2</Subscript> Particles under Hydroconversion Conditions

The mechanism of activation of a hydrogen molecule upon interaction with the surface of nanosized particles of the MoS₂ hydroconversion catalyst has been modeled using a quantum-chemical method of the density functional theory (DFT) with the hybrid functional B3LYP/dgdzvp in the cluster approximation. Two clusters, Mo₂S₄ and Mo₃S₆, have been considered as structural models of nanosized catalyst particles. It has been shown that the primary event of interaction of molecular H₂ with the catalyst surface is the chemisorption of hydrogen atoms on the molybdenum atom with H–H bond breaking. The local minima of the total electronic energy of the complexes in the chemisorption of hydrogen atoms on Mo and S atoms and the energy of the transition state between local minima have been found. It has been established that the stability of the complexes [Mo₃S₆…H₂] varies in the order: [···MoH₂] > [(S)H···(S)H] > [(Mo)H···(S)H] > [(Mo)H···(Mo)H] > [···SH₂].     

氢初压对渣油加氢产物胶体稳定性的影响及原因分析

在高温高压反应釜内,使用工业加氢转化催化剂对绥中36-1常压渣油进行了加氢反应,考察了氢初压对产物胶体稳定性的影响,并从产物的四组分组成、数均相对分子质量及胶质、沥青质的平均结构等方面对产生影响的原因进行了分析。结果表明,随着氢初压的升高,产物的稳定性先改善后略变差,其稳定性的改善可降低焦炭收率;产物的四组分中饱和分的含量增大,芳香分、胶质的含量变化不大,沥青质含量降低;芳香分、胶质的相对分子质量先增大后减小,沥青质的相对分子质量逐渐减小;胶质、沥青质的H/C原子比先增大后减小,芳香碳分率先降低后增大,二者结构性质的改变决定了产物胶体稳定性的变化趋势。     

DEVELOPMENT OF HIGH-PERFORMANCE HEAVY OIL HYDROCRACK1NG CATALYSTS: CHARACTERIZATION OF ATMOSPHERIC RESIDUE FEED

ABSTRACT

The characterization results of the atmospheric residue obtained from Saudi Arabian Light crude oil show the complex nature and composition of this material. The distillation results showed that about 50 percent of Arab Light crude is the atmospheric residue. The elemental analysis of the residue showed that high amount of carbon, sulfur and nitrogen is present along with heavy metals such as nickel and vanadium. The determination of hydrocarbon types by HPLC exhibited that 12% polars and 27% aromatics are present along with 6% asphaltenes. Nuclear magnetic resonance study conducted on the residue and its fraction provides a detailed composition in terms of aliphatic and aromatic nature of the residue and its fractions. The results showed that the residue contains 21% aromatic and 79% aliphatic carbon. The aliphatic carbon is present in saturates and as side chains of aromatic and polar molecules whereas the aromatic carbons are those in the ring structure. Asphaltenes separated from the residue were characterized for their different properties to understand its complexity. The use of electron spin resonance spectroscopy provides determination of the free radicals present in the residue. Asphaltenes were analyzed using the state-of-the-art high temperature high pressure electron spin resonance (ESR) technique in the temperature range 20 to 625 °C and at 30 and 50 bar hydrogen pressure. The ESR determination at 30 bar shows that me pressure was not enough to prevent the boiling of the asphaltene and thus a decrease in the spin concentration was observed beyond 350 °C temperature. The data at 50 bar pressure showed the adequacy of this pressure for ESR measurement. The PMRTA analysis of asphaltene showed a decrease in residual hydrogen with increasing temperature.     

氢初压对塔河沥青质加氢反应过程的影响

以十氢萘为溶剂,在高压釜内考察了氢初压对塔河常压渣油沥青质（正庚烷不溶物）加氢转化反应过程的影响。结果表明：氢初压由8.0 MPa增加到14.0 MPa时,(气体+汽油)收率增加,焦炭产率降低,而沥青质的转化率、柴油收率均先增加后降低,在12 MPa时出现最大值,渣油收率先降低后增加在12 MPa时出现最小值;在一定范围内,氢初压的增加有利于沥青质的加氢转化,但过高的氢初压会导致催化剂表面的油膜厚度增加,阻碍反应物向催化剂表面扩散,不利于沥青质的加氢反应;随着氢初压的增加,硫、氮脱除率增加,加氢后沥青质的平均相对分子质量降低,但变化幅度均随氢初压的增加而减小。     

CATALYTIC HYDROTREATMENT OF PETROLEUM RESIDUE

ABSTRACT

Iraqi reduced crude (350°C+) with a sulfur content of 4.3 wt% and a total metal content (Ni+V) of 141 WPPM was n-heptane deasphalted at specified conditions. The deasphalted oil (97.2 wt% of original residue) contains 4.1 wt% of sulfur and 103 ppm of metal. The original reduced crude and deasphalted oil were hydrotreated on a commercial Ni-Mo-alumina catalyst presulfided at specified conditions in a laboratory trickle-bed reactor. The reaction temperatures varied from 300 to 420°C with the liquid hourly space velocity (LHSV) ranging from 0.37 to 2.6 h^?1. Hydrogen pressure was kept constant throughout the experiments at 6.1 MPa, with a hydrogen/oil ratio of about 300 NLL^?1 (normal liters of hydrogen per liter of feedstock). Analysis for sulfur, nickel, vanadium and n-pentane asphaltenes were carried out for hydrotreated products from both the original residue and the deasphalted oil. The comparison of the results obtained for the hydrotreatment of deasphalted oil and original reduced crude indicates that the removal of sulfur, nickel and vanadium was higher for the deasphalted oil than those obtained for the non-deasphalted residue over the entire range of conversion. The exclusion of extremely high molecular weight asphaltenes by n-heptane deasphalting seems to improve the access of oil into catalyst pores resulting in higher desulfurization and conversion of the lower molecular weight asphaltenes. The sulfur content of n-pentane precipitated asphaltenes remained unchaneed with LHSV for various temperature for hydrotreated products produced from both deasphalted oil and original reduced crude.