Hydrogenation of aromatic hydrocarbons over nickel–tungsten sulfide catalysts containing mesoporous aluminosilicates of different nature

The hydrogenation of naphthalene, toluene, and 2-methylnaphthalene used as model compounds; the hydrodearomatization of the methylnaphthalene fraction; and the hydrocracking of oil sludge over Ni–W sulfide catalysts supported on BEA/TUD, BEA/SBA-15, and ZSM-5/SBA-15 composites containing SBA-15 and TUD mesoporous silicates have been studied. Catalytic tests have been conducted in an autoclave at 300–400°C and an initial hydrogen pressure of 50–90 atm. It has been found that the highest activity is exhibited by the catalyst based on the ZSM-5/SBA-15 (1) composite prepared by the double-templating synthesis and characterized by a specific surface area of 400 m²/g and an acidity of 409 μmol/g. Thus, in the case of dearomatization of the methylnaphthalene fraction at 300°C and an H₂ pressure of 50 atm, the content of diaromatic compounds has decreased from 99.0 to 53.4%, while the amount of sulfur compounds has decreased almost 15-fold. The hydrocracking of oil sludge over NiW/ZSM-5/SBA-15 (2) at 400°C and an H₂ pressure of 90 atm has led to an increase in the content of light fractions to 52%.     

W 对 W-Ni2P/SBA-15催化剂结构及二苯并噻吩氢脱硫性能的影响

 以硝酸镍为镍源,磷酸氢二铵为磷源,介孔分子筛 SBA-15为载体,采用共浸渍法制备Ni₂P/SBA-15前驱体,再将一定量的偏钨酸铵水溶液引入,采用程序升温还原制备了一系列 W-Ni₂P/SBA-15催化剂。采用 XRD、N₂吸附-脱附、NH₃-TPD 和 XPS 表征了催化剂的结构,并评价了催化剂的二苯并噻吩加氢脱硫活性。结果表明,W-Ni₂P/SBA-15催化剂中均只存在Ni₂P物相;催化剂的比表面积和孔体积随着W含量的增加先增大后减小;强酸量和总酸量都随W含量的增加有明显增加;W的加入使得催化剂表面的 Ni^δ+含量有所降低,而 P^δ-含量有所增加;在大于360℃时,催化剂对二苯并噻吩具有很好的深度加氢脱硫活性,并且以直接脱硫生成联苯的脱硫机理为主。     

硫化行为对Ni2P/SBA-15催化剂结构和加氢脱硫性能的影响

以介孔分子筛SBA-15为载体、硝酸镍为镍源、磷酸氢二铵为磷源,等体积浸渍法制备了Ni2P/SBA-15催化剂前驱体,然后在H2流中程序升温还原,得到Ni2P/SBA-15催化剂,再用CS2溶液对催化剂进行了硫化处理,制备出了硫化态xCS2-Ni2P/SBA-15催化剂。采用XRD、N2吸附-脱附、XPS对催化剂的结构进行了表征,对催化剂的二苯并噻吩加氢脱硫活性进行了评价,考察了硫化条件对催化剂结构和二苯并噻吩加氢脱硫催化活性的影响。结果表明,xCS2-Ni2P/SBA-15催化剂的物相有Ni2P、Ni12P5、Ni3S2,催化剂的比表面积随硫化溶液中CS2质量分数的增加有一定程度的增加,催化剂表面的Ni以Niδ+和Ni 2+形式存在,P以Pδ-和P5+形式存在。采用5%CS2硫化溶液硫化的催化剂对二苯并噻吩加氢脱硫具有最高的催化活性,380℃时二苯并噻吩的转化率可达99.3%。硫化过程形成的Ni3S2活性物相对二苯并噻吩的转化和直接脱硫都有利。     

Kinetics and mechanisms of the catalytic thermal cracking of asphaltenes adsorbed on supported nanoparticles

The production of heavy and extra-heavy oil is challenging because of the rheological properties that crude oil presents due to its high asphaltene content. The upgrading and recovery processes of these unconventional oils are typically water and energy intensive, which makes such processes costly and environmentally unfriendly. Nanoparticle catalysts could be used to enhance the upgrading and recovery of heavy oil under both in situ and ex situ conditions. In this study, the effect of the Ni-Pd nanocatalysts supported on fumed silica nanoparticles on post-adsorption catalytic thermal cracking of n-C7 asphaltenes was investigated using a thermogravimetric analyzer coupled with FTIR. The performance of catalytic thermal cracking of n-C7 asphaltenes in the presence of NiO and PdO supported on fumed silica nanoparticles was better than on the fumed silica support alone. For a fixed amount of adsorbed n-C7 asphaltenes (0.2 mg/m2), bimetallic nanoparticles showed better catalytic behavior than monometallic nanoparticles, confirming their synergistic effects. The corrected Ozawa– Flynn–Wall equation (OFW) was used to estimate the effective activation energies of the catalytic process. The mechanism function, kinetic parameters, and transition state thermodynamic functions for the thermal cracking process of n-C7 asphaltenes in the presence and absence of nanoparticles are investigated.     

金属助剂对Ni2P/SBA-15催化剂结构及二苯并噻吩加氢脱硫性能的影响

 以介孔分子筛SBA-15为载体,硝酸镍为镍源,磷酸氢二铵为磷源,采用共浸渍法制备了 P/Ni 摩尔比为0.8的 Ni₂P/SBA-15催化剂,然后添加 Li、Na、K、Mg、Ca、Sr 和 Ba 等金属助剂,制备了一系列不同金属助剂的M-Ni₂P/SBA-15(其中M为 Li、Na、K、Mg、Ca、Sr 和 Ba)催化剂。采用 XRD 对该系列催化剂的结构进行了表征,并以二苯并噻吩质量分数为1%的二苯并噻吩/十氢萘溶液为模型化合物,在微型固定床反应器上评价它们的加氢脱硫(HDS)性能。结果表明,M-Ni₂P/SBA-15催化剂的活性相为 Ni₂P。不同的金属助剂对催化剂性能的促进作用不同,其中碱土金属Ca能够明显地提高 Ni₂P/SBA-15催化剂的 HDS 活性,Ca 质量分数为3.5%的Ca-Ni₂P/SBA-15催化剂的 HDS 活性最好。在反应压力3.0 MPa、反应温度360℃的条件下,3.5%Ca-Ni₂P/SBA-15催化剂催化的二苯并噻吩 HDS 的转化率达到98.6%。不同金属助剂以不同方式影响加氢脱硫反应的机理。       

Effect of reaction temperature and hydrogen donor on the Ni0@graphene-catalyzed viscosity reduction of extra heavy crude oil

Ni⁰@graphene nanocomposites were prepared via a solvothermal method and used as the catalysts for the viscosity reduction of extra heavy crude oil. Higher graphene content in Ni⁰@graphene nanocomposite has an adverse effect on its catalytic activity. The addition of tetralin and higher reaction temperature can obviously promote the catalytic activity. The catalyst accompanied by hydrogen donor can attain a viscosity reduction rate of 84.3% after the catalytic reaction under 280°C for 24 h and reduce the viscosity of crude oil from 174,219 to 27,352 mPa s (measured at 50°C).     

Fe0/Graphene Nanocomposite as a Catalyst for the Viscosity Reduction of Heavy Crude Oil

Fe⁰/graphene nanocomposites were prepared via a thermal polymerization method and used as a catalyst to reduce the viscosity of heavy crude oil. The nanocomposites were characterized by X-ray diffraction, transmission electron microscopy, N₂ adsorption-desorption isotherms and thermal analysis. Their performance on the aquathermolysis of heavy crude oil was assessed in an autoclave. Under the reaction conditions of 200°C and 24 h, the viscosity of the oil was remarkably reduced when the catalysts were added.     

Gasoline- and diesel-like products from heavy oils via catalytic pyrolysis

Heavy oil is less expensive than light crude oil, but heavy oil is more expensive to obtain light oil products. Conventional light crude oil resources are decreasing, therefore heavy oil resources will be needed more in the future. There are huge differences from field to field for heavy oil deposits. In terms of final productive use, heavy oil is considered as an unconventional resource. Heavy oil upgrading depends on four important factors: catalyst selection, heavy oil classification, process design, and production economics. Heavy and extra-heavy oils are unconventional reservoirs of oil. Globally, 21.3% of total oil reserves are heavy oil. Heavy oil is composed of long chain organic molecules called heavy hydrocarbons. The thermal degradation of the heavy hydrocarbons in heavy oil generates liquid and gaseous products. All kinds of heavy oils contain asphaltenes, and therefore are considered to be very dense material. The most similar technologies for upgrading of heavy oils are pyrolysis and catalytic pyrolysis, thermal and catalytic cracking, and hydrocracking. The amount of liquid products obtained from pyrolysis of heavy oil was dependent on the temperature and the catalyst. Pyrolytic oil contains highly valuable light hydrocarbons as gasoline and diesel components range. The constant increase in the use of crude oils has raised prices of the most common commercial conventional products and consequently seeking for new alternative petroleum resources, like some unconventional oil resources, becomes an interesting issue. The mass contents of gasoline, diesel, and heavy oil in the crude oil are 44.6%, 38.3%, and 17.1%, respectively. The gasoline yield from the heavy oil catalytic (Na₂CO₃) pyrolysis is higher than the diesel efficiency for all conditions. The yield of gasoline products increases with increasing pyrolysis temperature (from 230°C to 350°C) and percentage of catalyst (from 5% to 10%). The yields of gasoline-like product are from 21.5% to 39.1% in 5% catalytic run and from 32.5% to 42.5% in 10% catalytic run. The yields of diesel-like product are from 9.3% to 29.8% in 5% catalytic run and from 15.5% to 33.7% in 10% catalytic run.     

Fischer-Tropsch synthesis in a slurry reactor in the presence of nanosized cobalt catalysts synthesized in situ in a hydrocarbon medium

Fischer-Tropsch synthesis in a slurry reactor at a pressure of 20 atm and a temperature of 220–300°C in the presence of 100Co : 2Pd : (5–50)Al₂O₃ and 100Co : 2Pd : (20–50)ZrO₂ (parts by weight) catalysts in situ synthesized in a hydrocarbon medium has been studied. The catalysts were prepared by the decomposition of cobalt salts and promoters in melted petroleum paraffin P-2 at 300°C and in situ reduced with hydrogen. It has been found that the nanocatalyst containing 20 parts by weight of ZrO₂ exhibits the highest activity in the Fischer-Tropsch synthesis and provides the yield of liquid products of 70 g/m³ at a CO conversion of 80%.     

Efficient ozonation of reverse osmosis concentrates from petroleum refinery wastewater using composite metal oxideloaded alumina

Novel Mn–Fe–Mg-and Mn–Fe–Ce-loaded alumina(Mn–Fe–Mg/Al_2O_3 and Mn–Fe–Ce/Al_2O_3) were developed to catalytically ozonate reverse osmosis concentrates generated from petroleum refinery wastewaters(PRW-ROC). Highly dispersed 100–300-nm deposits of composite multivalent metal oxides of Mn(Mn~(2+)), Mn~(3+),and Mn~(4+), Fe(Fe~(2+))and Fe~(3+) and Mg(Mg~(2+)), or Ce(Ce~(4+)) were achieved on Al_2O_3 supports. The developed Mn–Fe–Mg/Al_2O_3 and Mn–Fe–Ce/Al_2O_3 exhibited higher catalytic activity during the ozonation of PRW-ROC than Mn–Fe/Al_2O_3, Mn/Al_2O-3, Fe/Al_2O_3, and Al_2O_3. Chemical oxygen demand removal by Mn–Fe–Mg/Al_2O_3-or Mn–Fe–Ce/Al_2O_3-catalyzed ozonation increased by 23.9% and23.2%, respectively, in comparison with single ozonation.Mn–Fe–Mg/Al_2O_3 and Mn–Fe–Ce/Al_2O_3 notably promoted áOH generation and áOH-mediated oxidation. This study demonstrated the potential use of composite metal oxide-loaded Al_2O_3 in advanced treatment of bio-recalcitrant wastewaters.     

Hydrogen production by catalytic methane decomposition over Ni,Co, and Ni-Co/Al2O3 catalyst

Hydrogen is a chief source of energy. Catalytic decomposition produces hydrogen and carbon. In this work, x%M/Al₂O₃ (where M is Ni, Co and combined Ni-Co, and x is 10%, 15%, and 30%) has been successfully employed as a catalyst. The effect of activation temperature and active metal type and loading on catalyst perfomance was investigated. The catalysts were characterized with BET, XRD, TPO, TPR, TEM, XPS, and Raman. The results displayed that the 30%Co/Al₂O₃ catalyst activated at 500°C provided the greatest catalytic performance toward methane conversion. 30%Co/Al₂O₃ catalyst activated at 500°C formed amorphous carbon.     

Hydrotreating of vacuum gas oil on modified Ni–Mo/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> catalysts

The effect of the introduction of P₂O₅ into Ni–Mo/Al₂O₃ catalysts on their activity in the hydrotreating of vacuum gas oil has been studied. As the support, γ-Al₂O₃ prepared from aluminum hydroxide AlOOH powder of the TH-100 brand (Sasol) has been used. The catalytic properties of the catalysts obtained have been examined in the hydrotreating of vacuum gas oil in a continuous-flow unit under hydrogen pressure. The amounts of sulfur and polycyclic aromatic hydrocarbons, the hydrocarbon group composition, and the carbon residue of the feedstock and the hydrotreating product have been determined. The catalysts after testing have been studied using differential thermal analysis in combination with thermogravimetry (DTA–TGA); the influence of the amount of the modifier on the catalytic activity and coking of the catalysts has been shown.     

Comparative thermal study of heavy crude oils by DSC

Crude oil represented 50% of primary energy consumption in the world at the beginning of this decade. For each reservoir existent of conventional petroleum or gas there is three times the amount of heavy crude oil in the planet. The present work investigates the thermal behavior of three heavy crude oils from Brazilian basins. It was possible to make an interesting comparison for the same petroleum due to the use of different DSC equipment, especially for the extra heavy crude oils. The petroleum sample with the lowest °API exhibited the highest value for specific heat capacity between all studied samples.     

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.     

EFFECT OF IRON CATALYST ON THE COMPOSITION OF OIL FROM COAL LIQUEFACTION

ABSTRACT

The effect of two iron catalysts, red mud and CGS S-G, as well as C0-Mo/AI₂O3 and Ni-Mo/Al₂03 commercial catalysts on the composition of oil derived from the liquefaction of Japanese subbituminous coal have been investigated comparatively by conventional autoclave experiments at 440 and 450^°C under initial hydrogen pressure of 85kg/cm² G with tetralin to coal weight ratio of 3. From the results obtained at 450^°C, total conversion and the yield of gas revealed almost same level with four catalysts, but the oil product from molybdenum catalysts showed higher yield than that from iron catalysts. CGS S-G catalyst also showed higher yield of oil product than red mud catalyst. Reaction behavior of two iron catalysts were also tested by solvent recycle mode experiments.     

Ni~(2+)和Sn~(2+)改性的SO_4~(2-)/ZrO_2固体超强酸催化剂对稠油的降黏性能

稠油黏度高的特性使其开采难度较大。为降低胜利油田稠油的黏度,制备了金属离子(Ni2+和Sn2+)改性的SO42-/ZrO2固体超强酸催化剂,考察了这两种催化剂对稠油的降黏性能。实验结果表明,Ni2+和Sn2+改性的SO24-/ZrO2固体超强酸催化剂能在较低的温度下催化稠油降黏,在反应温度240℃、压力3~4MPa、反应时间24h、稠油与催化剂质量比100∶0.05的条件下,稠油的黏度由0.319Pa.s分别降至0.135Pa.s和0.163Pa.s,降黏率达57.7%和48.9%。反应后,稠油中的饱和烃含量增加,芳烃、胶质和沥青质含量减少,杂原子S和N的含量降低。同时发现,水的存在对稠油降黏不利。     

Co-hydrotreating of straight-run diesel fraction and vegetable oil on Co(Ni)-PMo/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> catalysts

The process of co-hydrotreatment of straight-run diesel fraction (DF) and vegetable oil (VO) on Co(Ni)-PMo/Al₂O₃ catalysts prepared from H₃PMo₁₂O₄₀ and cobalt (nickel) citrate has been studied. It has been shown that under conditions close to those in the industry, the complete conversion of fatty acid triglycerides (FATG) is achieved on the catalysts of both types to give an ultraclean hydrotreating product in a 97% yield and a cetane number of 5 points above that of the hydrotreating product of the DF alone. The degree of hydrodesulfurization (HDS) is reduced more significantly on the Co-PMo/Al₂O₃ catalyst than in the case of Ni-PMo/Al₂O₃. The catalysts are more susceptible to deactivation in the hydrotreating of the blended feedstock containing VO. The Co-PMo/Al₂O₃ sample is less stable than Ni-PMo/Al₂O₃. Examination of the spent catalysts by transmission electron microscopy has shown that the average particle length of the active phase of Co-PMo/Al₂O₃ increases, whereas this increment for Ni-PMo/Al₂O₃ is insignificant, indicating higher stability of particles of the NiMoS phase. Thus, the co-hydrotreating of petroleum fractions and vegetable oil is more reasonable to carry out on NiMo/Al₂O₃ catalysts.     

Characterization of Al2O3–ZrO2 Mixed Oxide Supported Mo Hydrotreating Catalyst

Abstract

A series of molybdenum catalysts supported on Al₂O₃–ZrO₂ mixed oxide containing 50% ZrO₂ and 50% Al₂O₃ were prepared by incipient wetness technique and characterized by BET surface area, X-ray diffraction, temperature programmed reduction and oxygen chemisorption. The catalytic activities for hydrodesulphurization (HDS), hydrogenation (HYD), and hydrocracking (HYC) were determined using thiophene, cyclohexene, and cumene as model compounds, respectively. Results indicate that up to 8 wt% Mo loading, the catalyst is well dispersed and crystallite growth occurred beyond this loading. Also both oxygen uptake and catalytic activities increase with Mo loading up to 8 wt% and then decreases at higher loading. A linear correlation was obtained between oxygen uptake and all catalytic activities and the correlation coefficients obtained suggest that the order of catalytic activities for HDS, HYD, and HYC is: HDS > HYD > HYC. Furthermore, the catalytic activities of the mixed oxide supported catalyst for HDS, HYD, and HYC were higher than those supported on pure alumina and pure zirconia. The incorporation of 3% Co on 8% Mo catalyst was determined to result in enhanced activity for HDS, HYD, and HYC.     

Hydrogen treatment of vacuum gas oil on sulfide catalysts: Influence of composition and porous structure

Three samples of γ-Al₂O₃ with different textural characteristics have been synthesized from AlOOH powders (Sasol). Ni(Co)Mo/Al₂O₃ catalysts have been prepared by single impregnation of the γ-Al₂O₃ samples with solutions of active ingredients. The morphology of the active phase of the sulfided samples has been studied by high-resolution transmission electron microscopy. The catalytic activity has been measured with the use of vacuum gas oil (VGO) as a feedstock at temperatures of 360, 390 and 420°C. After catalytic activity measurements, the catalysts have been investigated by means of differential thermal and thermographic analysis (DTA-TGA). Textural characteristics of the catalysts in the oxide and sulfide forms have been determined, including those after the measurement of activity in VGO hydrotreating. The textural characteristics of the samples have been shown to correlate with the extent of the hydrogenation reactions of aromatic hydrocarbons and hydrodesulfurization. The highest hydrogenating and hydrodesulfurizing activity has been displayed by the sample on the support with the largest specific surface area and the smallest effective pore radius.     

Catalytic Performance of Modified HZSM-5/Al2O3 Catalysts for Nonhydrodewaxing

The HZSM-5/Al₂O₃ molecular sieve catalyst was modified by phosphoric acid, tetraeth-oxysilane, tetrabutyl titanate, and boric acid, respectively. Properties of modified catalysts are characterized. The results show that the specific surface area declines and the acid density increases after modification of the catalysts, and the strong acid strength of Si/HZSM-5/Al₂O₃ catalyst enhanced. Modified catalysts performances are evaluated on fixed bed reactor using hydrocracking tail oil from a refinery as raw material. Results show that the Si/HZSM-5/Al₂O₃ catalyst has better catalytic dewaxing effect and stability than the other modified catalysts.