Hydrocracking Of Gas Oil Research Articles

Impact of lanthanum ion exchange and steaming dealumination on middle distillate production using nanosized Y zeolite catalysts in hydrocracking reactions.

In the field of hydrocracking reactions, achieving optimal middle distillate yields remains a persistent challenge with commercially available zeolite Y catalysts. This limitation is attributed to challenges related to diffusion constraints within the catalyst. In response, we present a promising solution not only to these problems but also to the challenges encountered in nanosized Y zeolites when attempting to generate acidic sites within their structure and when analyzing their performance in vacuum gas oil hydrocracking. NiMo catalysts based on nanosized Y zeolites with different crystal sizes exchanged with lanthanum, effectively address diffusion issues and significantly enhance catalyst performance compared to dealuminated nanosized and commercial Y zeolite under the same reaction conditions. The catalysts were characterized by TGA, ICP-OES, XPS, N2 physisorption, FT-IR for pyridine acidity, TEM-mapping, and the 3-methyl thiophene reaction to test the hydrogenating capacity. Surface analysis and microscopy showed greater porosity in the catalysts with smaller zeolites and different arrangements of their components. The catalysts based on steamed protonated nanosized Y zeolites with a larger size and lanthanide nanosized Y zeolite with a smaller size yielded more middle distillates. Research provides a comprehensive analysis, providing a correlation between the catalytic performance and the size of the nanosized Y zeolite.

Hierarchical submicrosized Y zeolites prepared by sequential desilication–dealumination post-synthesis modification and their catalytic performance in vacuum gas oil hydrocracking

The desilication-dealumination process allowed the production of structurally more stable submicrometric Y zeolites with hierarchical porosity and high crystallinity.

Post‐Synthetic Ensembling Design of Hierarchically Ordered FAU‐type Zeolite Frameworks for Vacuum Gas Oil Hydrocracking

AbstractZeolites hold importance as catalysts and membranes across numerous industrial processes that produce most of the world's fuels and chemicals. In zeolite catalysis, the rate of molecular diffusion inside the micropore channels defines the catalyst's longevity and selectivity, thereby influencing the catalytic efficiency. Decreasing the diffusion pathlengths of zeolites to the nanoscopic level by fabricating well‐organized hierarchically porous architecture can efficiently overcome their intrinsic mass‐transfer limitations without losing hydrothermal stability. We report a rational post‐synthetic design for synthesizing hierarchically ordered FAU‐type zeolites exhibiting 2D‐hexagonal (P6mm) and 3D‐cubic (Ia d) mesopore channels. The synthesis involves methodical incision of the parent zeolite into unit‐cell level zeolitic fragments by in situ generated base and bulky surfactants. The micellar ensembles formed by these surfactant‐zeolite interactions are subsequently reorganized into various ordered mesophases by tuning the micellar curvature with ion‐specific interactions (Hofmeister effect). Unlike conventional crystallization, which offers poor control over mesophase formation due to kinetic constraints, crystalline mesostructures can be developed under dilute, mild alkaline conditions by controlled reassembly. The prepared zeolites with nanometric diffusion pathlengths have demonstrated excellent yields of naphtha and middle‐distillates in vacuum gas oil hydrocracking with decreased coke deposition.

Post-Synthetic Ensembling Design of Hierarchically Ordered FAU-type Zeolite Frameworks for Vacuum Gas Oil Hydrocracking.

Zeolites hold importance as catalysts and membranes across numerous industrial processes that produce most of the world's fuels and chemicals. In zeolite catalysis, the rate of molecular diffusion inside the micropore channels defines the catalyst's longevity and selectivity, thereby influencing the catalytic efficiency. Decreasing the diffusion pathlengths of zeolites to the nanoscopic level by fabricating well-organized hierarchically porous architecture can efficiently overcome their intrinsic mass-transfer limitations without losing hydrothermal stability. We report a rational post-synthetic design for synthesizing hierarchically ordered FAU-type zeolites exhibiting 2D-hexagonal (P6mm) and 3D-cubic (Ia d) mesopore channels. The synthesis involves methodical incision of the parent zeolite into unit-cell level zeolitic fragments by in situ generated base and bulky surfactants. The micellar ensembles formed by these surfactant-zeolite interactions are subsequently reorganized into various ordered mesophases by tuning the micellar curvature with ion-specific interactions (Hofmeister effect). Unlike conventional crystallization, which offers poor control over mesophase formation due to kinetic constraints, crystalline mesostructures can be developed under dilute, mild alkaline conditions by controlled reassembly. The prepared zeolites with nanometric diffusion pathlengths have demonstrated excellent yields of naphtha and middle-distillates in vacuum gas oil hydrocracking with decreased coke deposition.

Coprocessing Partially Hydrodeoxygenated Hydrothermal Liquefaction Biocrude from Forest Residue in the Vacuum Gas Oil Hydrocracking Process

Coprocessing Partially Hydrodeoxygenated Hydrothermal Liquefaction Biocrude from Forest Residue in the Vacuum Gas Oil Hydrocracking Process

Combining USY and ZSM-23 in Pt/zeolite hydrocracking catalyst to produce diesel and lube base oil with improved cold flow properties

The effect of the combined use of three-dimensional large-pore USY zeolite and one-dimensional medium-pore ZSM-23 zeolite to enhance the cold flow properties of hydrocracking products was studied. Based on the results of monozeolite catalysts testing in hexadecane hydroconversion, the compositions of bizeolite catalysts for vacuum gas oil hydrocracking were selected. The catalyst compositions were selected, considering that both zeolite components operate in a similar temperature range and contribute to hexadecane conversion. It has been shown that due to an appropriately selected combination of USY and ZSM-23 zeolites in the catalyst, both zeolites perform together, complementing each other, which ensures good conversion of both n-alkanes and isoalkanes during vacuum gas oil hydrocracking. As a result, it is possible to significantly improve the cold flow properties of the obtained hydrocracking products while maintaining the activity and selectivity for the target products of Pt/USY-ZSM-23 catalyst at the level of conventional Pt/USY catalyst. The cold filter plugging point of the diesel fraction decreases from −10 to less than −44 °C and the pour point from −17 to less than −50 °C. The pour point of lube base oil decreases from 23 to less than −27 °C. The improvement of the cold flow properties is accompanied by only a slight worsening of the other important product characteristics, such as diesel fraction cetane index and lube base oil viscosity index.

Catalytic advances in vacuum gas oil hydrocracking

Hydrocracking still maintains the pivotal role in the industry owing to the production of highly demanded transportation fuels. Having comprised pretreatment of VGO, comparative research onrecent catalysts, this review paper provides athorough picture about all consecutive steps in the hydrocracking process of vacuum gasoil. Discussing recovery of VGO from vacuum residue with minimum sulfur content, the focus was put on the catalyst characterizations and their influence on the conversion of VGO, the yield of middle distillate, gasoline as well asnaphtha. Both zeolite and amorphous catalysts have undergone a comparative analysis interms of their hydrocracking properties as well as catalytic activities during provided conditions. The article also examines the process of hydrocracking of vacuum gas-oil from Baku oils with the participation of modified aluminosilicate catalyst containing Ni, Mo to obtain high-quality raw materials for environmentally friendly diesel fuel and catalytic cracking process. The hydrocracking process of vacuum gas-oil conducted at 3-8 MPa pressure, 400-450 °C temperature range, in a flow-type Hungarian unit with a reactor capacity of 200 ml. During the investigations of temperature on hydrocracking process it was revealed that, when temperature rises from 400 to 460 °С the yield of diesel fraction increases from 35 to 50% wt. The yield of gasoline fraction constitutes 0-6% wt. and the produce of residue fraction decreases from 65% to 45%. With increasing of temperature from 400 °C to 450 °C the amount of sulphur decreases from 0.01% to 0.005% in composition of diesel fraction. Keywords: vacuum gasoil; hydrocracking; diesel fraction; alumosilicate; catalyst; hydrodesulfurization.

Исследование процесса гидрокрекинга вакуумного газойля в присутствии цеолитсодержащего катализатора, модифицированного переходными металлами

The article presents the results of hydrocracking of vacuum gas oil. The effect of volume rate on the course of the process has been studied. The study of the effect of the volumetric velocity on the hydrocracking of the vacuum gas oil at a pressure of 5 MPa and at a temperature of 440°C shows that the favorable volumetric velocity is between 0.8–1.0 h–1. As the volume ratio increases from 1.5 to 2 h–1, the amount of sulfur and unsaturated hydrocarbons increases in the diesel fraction, while the yield of the diesel fraction decreases. The density of the diesel fraction and the boiling point of 50% increase.

Effect of rare earths on acidity of high-silica ultrastable REY zeolites and catalytic performance of NiMo/REY+Al2O3 catalysts in vacuum gas oil hydrocracking

A series of low-sodium ultrastable Y zeolites (SiO 2 /Al 2 O 3 ≈ 25) partially exchanged with different amounts of rare earth ions (RE 2 O 3 = 0.55–3.32 wt%) was prepared and characterized by XRD, IR spectroscopy, elemental analysis, N 2 adsorption, as well as 29 Si and 27 Al NMR. The effect of RE content on the number and relative strength of acid sites of REY zeolites was studied by IR spectroscopy of absorbed CO and pyridine. The increase in the RE content in the zeolites leads to a decrease in the concentration of strong Brønsted acid sites (BAS) in faujasite cages (bridged Si–O(H)–Al groups), especially the concentration of stronger BAS associated with Si–O(H)–Al groups polarized by extra-framework aluminum species. At the same time, the concentration of less acidic OH groups connected with extra-framework ions increases possibly due to the formation of additional RE–O(H)–Al groups. The total number of BAS in all the samples remains close. An increase in the RE 2 O 3 content from 0.55 to 3.32 wt% decreases almost by half the ratio of strong BAS in faujasite cages to less acidic extra-framework BAS. The catalytic performance of NiMo/(30 wt% REY + 70 wt% Al 2 O 3 ) catalysts was evaluated in hydrocracking of vacuum gas oil. The enhanced hydrocracking activity and selectivity to middle distillates are mainly achieved due to the optimal acidity of the zeolites. • Synthesis of USY zeolites (Si/Al≈12.5) exchanged with different amount of RE ions. • Strong BAS/less acidic extraframework BAS ratio decreases with RE content increase. • Stronger BAS (Si–O(H)–Al groups polarized by EFAL species) are exchanged first. • Additional BAS are associated with the formation of RE–O(H)–Al groups in supercages. • NiMo/REY + Al 2 O 3 with optimal acidity exhibits improved hydrocracking performance.

Impact of Feedstock Properties on the Deactivation of a Vacuum Gas Oil Hydrocracking Catalyst

The aim of this study was to understand the impact of vacuum gas oil (VGO) properties on the deactivation rate of a hydrocracking catalyst (nickel–molybdenum sulfide dispersed on a carrier containing USY zeolite). For this purpose, two hydrotreated feeds of different densities, organic nitrogen (∼120–150 ppmw) and aromatic content, were hydrocracked under operating conditions that favor catalyst deactivation, that is, high temperature (T = 418 °C) and high space velocity (LHSV = 3 h–1). The catalyst performance was followed by measuring the VGO conversion (370 °C+ petroleum cut) and determining the apparent kinetic constants for the main hydrocracking reactions (cracking, hydrodenitrogenation, hydrodesulfurization, and aromatics hydrogenation). The experiments were stopped after different times on stream (either 6 or 30 days) in order to assess the evolution of the catalyst as a function of time. The spent catalysts, obtained from three different reactor locations, were characterized by elemental and textural analyses and by thermogravimetry to investigate the quantity and nature of the coke formed. Catalytic tests with different model compounds (toluene and n-heptane) were carried out to determine the residual activity of the hydrogenating and acid catalyst functions. It was found that, at the evaluated conditions, both the nature and the content of organic nitrogen and aromatics compounds of the feedstock have a determinant role in the deactivation rate. Organic nitrogen determines the ratio between available metal and acid sites. The aromatics generate coke precursors on the available acid sites. Both factors play a coupled role that promotes coke deposition on the catalyst surface, which leads to an increase in the deactivation rate on top of the end boiling point of the feed.

Исследование закономерностей и разработка модели процесса гидрокрекинга вакуумного газойля

In this work, the regularities of the vacuum gasoil hydrocracking process were studied, which include: determination of the key components of the reacting mixture and key reactions, studying the thermodynamic regularities, identification of the regularities of the influence of technological parameters on the transformation of the key reacting components. The model of the process was developed.

Сравнение результатов моделирования процесса ректификации нефтяных фракций с использованием реальных и псевдокомпонентов

Today the stable work of a petrochemical plant and its installations, as well as its efficiency, mostly depends on the reliable and optimal operation of technological equipment. It is very common that technological equipment complexes do not work in an optimal mode, despite the fact that they are controlled by modern automated control systems. If the equipment is stopped for any reason, then no best technology or management systems can compensate for the economic costs and losses that arise in the event of equipment downtime. The solution to this problem is to create computer models that allow you to cover the technological equipment from a single point of view and conduct a number of necessary experiments without resorting to existing equipment. The computer model of the rectification unit is implemented when modeling the section of the technological scheme for the production of liquid fuel of the vacuum gasoil hydrocracking unit.

Practical Application of Hierarchical Beta Zeolite in a Vacuum Gas Oil Hydrocracking Catalyst

AbstractA hierarchical Beta zeolite has been successfully mass‐prepared hydrothermally and dynamically in a pilot‐scale autoclave by an economical and simple process with low‐cost raw materials. The characterization results indicated that the pilot‐scale hierarchical Beta zeolite has the same textural, structural, and acidic properties like the bench‐scale sample. Moreover, the catalyst composed of the pilot‐scale hierarchical H‐Beta zeolite showed higher activity and selectivity to the middle distillate than that containing microporous Beta zeolite in catalytic hydrocracking of vacuum gas oil (VGO) evaluated by an industrial pilot installation in running of 3000 h, due to the increased accessibility and the reduction of diffusion constraint of large molecules to acid sites in the Beta zeolite framework.

Computational Fluid Dynamic Modeling and Simulation of Hydrocracking of Vacuum Gas Oil in a Fixed-Bed Reactor

A four-lump computational fluid dynamic (CFD) model was proposed for the investigation of vacuum gas oil hydrocracking in a trickle-bed reactor. The experiment was conducted at 360–390 °C and 146 bar in the reactor at three different flow rates. It was found that the modeling predictions of vacuum gas oil cracking agreed well with the experimental measurements. Furthermore, the developed model analyzed the effects of the feed flow rate in the reactors on the concentration distribution and product yield. The maximum yields of the products including distillate (31%), naphtha (14%), and gas (3%) were obtained at the lowest feed flow rate. However, the feed flow rate enhancement from 0.1568 to 0.2059 kg·h–1 led to the increasing feed concentration and reducing the product concentration at the outlet of the reactor. The latter phenomenon was happened due to the decreasing feed residence time with the increasing mass flow rate.

Improved understanding of reaction kinetic identification problems using different nonlinear optimization algorithms

The correct answer regarding which nonlinear optimization algorithm should we use for a given problem is that “it depends.” In this paper, we would like to add that “it depends, but use multiple programs whenever possible.” Here we consider 23 algorithms, implemented in MATLAB, evaluating their performance both on a lumped kinetic model for vacuum gas oil hydrocracking and a few-step kinetic model for ethane pyrolysis; the former particularly raised our interest as the kinetic parameters have no reference values in such models. We can use the results of such a study to estimate model variance; moreover, the statistical analysis of the identified minimum values can also quantify the parameter uncertainty. We can also identify key operating conditions where the applied kinetic model shows the highest sensitivity to the identified parameters, opening up the possibility to further reduce the uncertainty by targeting additional experimental work or by refining the identification problem.

Impact of H-Oil vacuum residue hydrocracking severity on fluid catalytic cracking unit performance

The performance of both ebullated bed H-Oil vacuum residue (VR) hydrocracking and fluid catalytic cracking (FCC) of vacuum gas oils (VGO) is interrelated. The increase of H-Oil unit reaction temperature maximizes VR conversion and augments the aromaticity and density of the hydrocracked heavy oils. The FCC of VGO blends that contain more aromatic H-Oil VGOs is featured by a lower VGO conversion. It was found in this study that the reactivity of the H-Oil heavy oils depends on their molecular weight (T50) instead on their aromatics content as observed during catalytic cracking of straight run VGOs reported in other studies.

Citric Acid-Treated Zeolite Y (CY)/Zeolite Beta Composites as Supports for Vacuum Gas Oil Hydrocracking Catalysts: High Yield Production of Highly-Aromatic Heavy Naphtha and Low-BMCI Value Tail Oil.

Citric acid-treated zeolite Y (CY) and zeolite beta were mechanically mixed to obtain composite zeolites (CY-Beta) with various zeolite beta contents. The composite zeolites were used as the acid components of hydrocracking catalyst supports. The physical and chemical properties of the supports and catalysts were analyzed by N2 adsorption-desorption, XRD, SEM, and NH3-TPD. The mechanical mixing of CY and zeolite beta does not destroy the textual properties of the original zeolites. However, the acidity of the composite zeolite does not fit the linearly calculated value of the two zeolites because some of the acid sites are covered or reacted with other acid sites during the mixing process. In addition, weak acid sites favor the high yield of tail oil with low BMCI value. Compared with the CY-based and beta-based catalysts, the conversion and light oil yield of the CY-Beta-based catalyst was increased. The conversion, light oil yield, and petrochemical yield of the Ni-W/20CY-Beta(20)/ASA catalyst are 78.15, 65.0, and 83.7%, respectively. The BMCI value of the tail oil is 4.7, and the aromatic potential content (APC) of heavy naphtha (boiling point 65–177°C) is 42%. The 1,500 h pilot plant test of Ni-W/20CY-Beta(20)/ASA at 350°C, 7.0 MPa, 2.0 h−1 LHSV, and 800 H2/oil (v/v) shows that the activity remains stable during the 1,500 h evaluation. The heavy naphtha (APC about 41.0) yield of 41.2 illustrates that the catalyst has the ability to aromatize and cyclize the light fractions. The yield of diesel is about 25% with a cetane index (CI) of 59.2; the frozen point is lower than −45°C, and the cold filter plugging point is −35°C, demonstrating the isomerization performance for middle distillations. The yield of tail oil is 14.9% with a BMCI of 4.4, showing the high hydrogenation performance of the catalyst to transform the un-cracked tail oil to saturated hydrocarbon in order to reduce the BMCI value.

Reduction of lumped reaction networks based on global sensitivity analysis

In case of complex chemical systems in that many reactions occur between high numbers of species, it is often necessary to use some form of lumping in order to obtain a simpler kinetic model whose parameters can actually be determined from the available data. Designing a lumped reaction network, however, involves dealing with great degrees of freedom. One has to define the actual pseudocomponents, the reactions that take place in the system and finally, reliable kinetic parameters have to be identified for these reactions. This often results in high uncertainties regarding these kinetic models as well as in their limited usability in carrying out experimental design or other process engineering tasks. This point of interest is more often not get discussed than it is. The key idea of this paper is that the uncertainty of lumped kinetic models can be significantly diminished by reducing the size of the reaction network while also preserving the ability of the model to describe the observed behavior of the given system. To that end, we applied and evaluated five different global sensitivity analysis methods based on their performance, using the case studies of real plastic waste pyrolysis and vacuum gas oil hydrocracking. We point out that these tools can be effectively used to construct lumped reaction networks with fewer parameters to be estimated with narrower confidence intervals.

Phosphorous-Modified Beta Zeolite and Its Performance in Vacuum Gas Oil Hydrocracking Activity

The present work reports the synthesis of beta zeolite and its modification with phosphorous in different percentages of P2O5 (1 and 5%) and vacuum gas oil (VGO) hydrocracking (HCK) conversion and ...

Scale-up of a NiMoP/γAl2O3catalyst for the hydrotreating and mild hydrocracking of heavy gasoil

This contribution shows the acquired experience during the scale-up of a NiMoP/γAl2O3catalyst employed for the hydrotreating and mild hydrocracking of heavy gasoil. Three different strategies were adopted for preparing catalyst batches at pilot scale. They consisted on co-impregnation ofγ-alumina extrudates with aqueous solutions containing Ni and Mo salts and phosphoric acid in one or two successive steps. The textural, chemical composition, mechanical strength, metallic surface dispersion and elemental radial distribution profile properties were influenced by the impregnation procedure employed. The co-impregnation with diluted Ni, Mo and P solutions in two successive steps is the best way to prepare the catalyst. This procedure provides a catalyst that exhibits better physico-chemical properties and catalytic activity profile than the other impregnation methods investigated. Heat and mass transfer limitations became very important when preparing catalysts in large quantities. The diffusion intra-particle and extra-particle was observed influenced by the density and viscosity properties of the metallic solution, the liquid-solid contact angle, the reactivity of phosphate, polymolybdate and phosphomolybdate species with the alumina surface hydroxyl groups, the raise of temperature produced in the solid particles during the initial impregnation step and the porosity properties of the catalyst support. It was concluded that the fine control of the metal distribution on the alumina surface during the impregnation is crucial for producing highly active uniform catalysts.