Hydroconversion Processes Research Articles

Development of bimetallic Ru/Ni/SBA-16 catalysts for catalytic hydrogenation of bio-based furfural to 2-methylfuran and furfuryl alcohol

In this work, an efficient bimetallic catalyst was developed to serve as a key factor for the successful hydrogenation of biomass-derived furfural (FF) to the high-value-added chemicals, namely 2-methylfuran (2- MF) and furfuryl alcohol (FA). The bare SBA-16 (SB-16) and Rux/Niy/SBA-16 (RuxNiySB-16) catalysts with different weight percentages (x = 0.2, 0.4, 0.6, 0.8, 0.9 wt% and y = 0.8, 0.6, 0.4, 0.2, 0.1 wt%) were prepared through an in situ hydrothermal method. Characterization using XRD, FT-IR, FE-SEM, EDS, XPS, Pyridine FT-IR, and HR-TEM analysis confirmed the chemical and physical properties of the catalyst. To investigate the catalytic hydrogenation of FF to 2-MF using 2-propanol (2-PrOH) over RuxNiySB-16 catalysts, various reaction parameters such as reaction temperature, time, catalyst loading, and alcohol ratio have been carried out. Among the catalysts tested, the Ru0.8Ni0.2SB-16 catalyst demonstrated outstanding performance under mild reaction conditions, achieving 100% conversion of furfural and an impressive selectivity of 88% towards 2-MF. The high selectivity of 2-MF can be attributed to the combined influence of metal and acid sites on the catalyst surface. Notably, the most active Ru0.8Ni0.2SB-16 catalyst stability was confirmed through five recycling tests, as there was no significant leaching of Ru and Ni. The Ru0.8Ni0.2SB-16 catalyst showed the highest stability based on the recycling test results. The excellent properties of these RuxNiySB-16 catalysts are suitable for various industrial applications, including furfural hydrogenation and other hydroconversion processes.

Catalytic hydroconversion processes for upcycling plastic waste to fuels and chemicals

This review provides an overview of catalytic hydroconversion processes including hydrocracking, hydrogenolysis and hydrodeoxygenation for upcycling of plastic wastes into fuels and valuable chemicals.

Effective parameters of Mo recovery from spent homogeneous nanocatalyst in slurry phase hydroconversion processes

Molybdenum sulfide nanoparticles have an important role in catalytic behavior of hydroconversion catalyst. The extraction of Mo is a crucial issue because of great consumption, environmental regulations, high cost and depletion of high grades resources. In this work, Plackett-Burman design as a screening method is used to analyze the effects of six variables with the intent to increase the efficiency of molybdenum recovery from homogenous nanocatalysts in the slurry phase hydroconversion processes. These variables consist of leaching temperature, oxidation temperature, leaching time, oxidation time, hydrogen peroxide concentration, and ammonium carbonate concentration. This design offers the significant role of parameters that determining optimum recovery conditions for achieving the cost-efficient, shorter duration and more environmentally friendly process. The results show that the leaching time, hydrogen peroxide concentration, and ammonium carbonate concentration are effective parameters on molybdenum concentration with a degree of confidence of 95%. Based on the obtained results, the influences of leaching and oxidation temperatures and oxidation time were negligible. A linear model was obtained to predict operation conditions by effective parameters for estimating recovery. The maximum recovery is achieved at minimum leaching time (20 min), minimum hydrogen peroxide concentration (10 vol %) and maximum ammonium carbonate concentration (7 wt %).

THE MANAGEMENT OF SPENT CATALYST OF HYDROCONVERSION PROCESSES IN ASEAN REFINERIES

Catalytic processing is a keystone of today’s petroleum refining. The catalytic processes applied in the potreleum industry are generally large scale. In today’s operating climate of increased attentiveness toward environmental and safety issues, spent catalyst management options have became an important consideration for refiners. A catalyst deactivation determines how it can be handled after it is discharged from the processing unit. The type of the catalyst and its condition (whether it is considered hazardous) often determines the disposal route selected. Because of the self-heating and leaching problems associated with spent hydrotreating catalyst,it is recommended that refiners ship their spent catalysts to what is called “true recycles”. The U.S. Environmental Protection Agency (EPA), for example, is in the process of reevaluating the designation of spent hydroprocessing catalyst as an hazardous waste. Out of 3,837 MBPSD total crude oil currently processed in ASEAN (Brunai Darussalam, Indonesia, Malaysia, Philippenes, Singapore, Thailand, not including Vietnam, Laos and Myanmar) arround 61 percent volume is passed through catalytic processes (included hydroconversion processes 58 vol.%) to produce various fuel components such as gasoline and diesel oil. These hydroconversion processes use about 3,279 tons of catalyst with about 28 tons per day of spent catalyst. The present paper discusses briefly a survey on the management of spent catalyst of hydroconverion processes in ASEAN refineries and some aspects of catalyst poisoning of major hydroconversion processes in petroleum refinery. A survey on the management of spent catalyst from hydroconversion processes in ASEAN refineries is described in this paper.

Micro-/mesopores confined ultrasmall Cu nanoparticles in SBA-15 as a highly efficient and robust catalyst for furfural hydrogenation to furfuryl alcohol

The main difficulty in the liquid phase furfural hydrogenation process is the control of the selectivity to the target product among the possible ones. When copper catalysts are used, they often suffer from low stability in liquid medium. Herein, we report a general preparation method based on glycine-assisted in situ autocombustion to synthesize Cu supported catalysts. This method could lead to highly active, selective and stable catalysts in the liquid phase furfural hydrogenation. The resulting 10Cu-SBA-GLY catalyst (10 wt% Cu on SBA-15) could achieve a complete conversion of furfural to furfuryl alcohol under mild reaction conditions. Further, neither Cu leaching nor Cu NPs sintering were observed during the 5-run recycling tests, and the loss of conversion and selectivity stays below 3%. Such exceptional features make these Cu-SBA-GLY catalysts potential for the industrial applications not only in furfural hydrogenation but also in other hydroconversion processes.

Techno-economic analysis of used cooking oil to jet fuel production under uncertainty through three-, two-, and one-step conversion processes

Abstract The application of renewable jet fuel is an eco-friendly technique that can reduce greenhouse gas emissions. Based on existing commercial processes, this study aimed to evaluate the hydro-conversion processes for producing renewable jet fuel. Three process scenarios were compared, in which the feedstock used cooking oil (UCO) is converted to hydroprocessed renewable jet fuel (HRJ) and its byproducts. Then, the investment feasibility of the three processes was evaluated through an economic analysis and predicted by an uncertainty analysis. The results show that if the main product (HRJ) is the profit target, one-step conversion is the best choice. However, if we consider the overall economic benefits, the three-step conversion method is more suitable with an average more 11.94% chance of profiting than the one-stage under uncertain analysis, which means it is a considerably competitive approach with lower risk and only 0.31 $/L of minimum selling price of jet fuel (MJSP), because it has the advantages of a wider range application and higher value of byproducts which reduce the risk of a single factor contribution. From the sensitivity analysis, jet fuel price is the key factor which contributes 75–82% for one- and two-stage processes, but UCO price in three-stage process reach nearly 50%. In addition, due to the economic scale, scaling up the plant capacity will lead higher economic benefits. Therefore, an efficient UCO recovery system and three-stage process are the keys for the industrial development aspect through the value-chain analysis under uncertainty.

Biojet from Hydroconversion of Camelina Oil Mixed with Straight Run Gas Oil

In the current research study camelina non edible oil (CO) was used as renewable feedstock for production of jet fuel by hydroconversion processes. The vegetable oil was mixed with straight run gas oil (SRGO) at 10, 15 and 20 % ratio. The hydrotreating experiments were carried out in micropilot plant flow reactor over NiMo/Al2O3 catalyst at 350oC and 380oC, 80 bar pressure 1h-1 and 1.5 h-1 liquid hourly space velocity (LHSV). The research focuses on the influence of the SRGO-CO ratio, temperature and LHSV on the yields and the physiochemical properties of the biojet (160-300oC) obtained. The hydrotreating reactions which occur during the process, produce 36-45% wt jet yields but bad flow properties due to the n-paraffins with 13-20 carbon atoms in molecules obtained from hydrogenation of vegetable oil. These characteristics can be corrected by hydroisomerisation. The results show that the hydrotreatment of CO and SRGO-CO mixtures are an alternative for biofuel production with characteristics similar to jet fuel.

Recirculation and Regeneration of Molybdenum-Containing Ultradispersed Catalysts in the Hydroconversion Processes of Carbon-Containing Raw Materials: A Review

It was shown that hydroconversion processes with the use of ultradispersed molybdenum-containing catalysts are promising lines in the production of motor fuels from different forms of organic raw materials. Molybdenum disulfide is the catalytically active form regardless of the method of introduction and the composition of precursors used. This fact makes it possible to develop the general principles of the extraction of molybdenum compounds from the residues of the hydroconversion of organic raw materials. The known data on methods used for the extraction and regeneration of Mo-containing compounds in the hydrotreating of heavy charges and from molybdenite-containing minerals were generalized.

Tracing the Compositional Changes of Asphaltenes after Hydroconversion and Thermal Cracking Processes by High-Resolution Mass Spectrometry

With heavy crude oil refining on the rise, upgrading strategies are fundamental to yield high-value products. Hydroconversion and thermal cracking are well-established and widely used upgrading processes for heavy oils’ distillation cuts and residues. Recognizing molecular changes in these fractions after upgrading, particularly of asphaltenic compounds, is fundamental to understand and optimize the processes. In this work, we follow compositional changes in the asphaltene fraction of a Colombian heavy crude, after hydroconversion and thermal cracking, using high-resolution mass spectrometry. The liquid products from the upgrading processes were fractionated into maltenes and residual asphaltenes, with yields between 33% and 38% in maltenes from the original asphaltene feedstock. Contoured plots of double bond equivalents versus carbon number and van Krevelen diagrams show maltenic fractions exhibiting lower aromaticity, smaller molecular size, fewer heteroatomic species, and higher content of alkyl side ...

Sediment Formation in Residue Hydroconversion Processes and Its Correlation to Asphaltene Behavior

In this work, the link between asphaltene stability and sediment formation in hydroprocessing of residua is evaluated using two recently developed techniques for asphaltene characterization (Asphaltene Solubility Profile and Solubility Fractions). Several feeds as well as products coming from commercial units and pilot plants are examined in terms of asphaltene content and asphaltene stability. The results obtained confirm the relationship between stability, structural asphaltene characteristics, and sediment formation in products. It was found that stability, asphaltene content, and nature of the feeds are key factors in sediment formation. Two sets of correlations were found: those that correlate sediment with product characteristics and those that correlate sediment with feed characteristics and operational conditions. Both sets of correlations include asphaltene solubility characteristics and content as key parameters. These findings indicate that proper asphaltene characterization of feeds can help to reduce fouling in operating units by facilitating feed selection and adjustment of operational conditions. Additionally, it has been shown that the two proposed methods can be used to monitor sediment formation during hydroconversion as well as to evaluate solvents for blending in a fast and simple way compatible with a refinery lab environment.

Toward a better understanding of residue hydroconversion catalysts using NiMo catalysts supported over silica grafted Al2O3

The aim of this work was to investigate the influence of the catalyst acidity in vacuum residues hydroconversion processes. To achieve this goal, a grafting procedure was applied in order to incorporate silicon at the surface of alumina carriers. The corresponding NiMoP catalysts with different silicon amounts in the support were evaluated in order to assess the conversion rate and mechanism of a Safaniya vacuum residue in a batch reactor at 370°C. A multi-techniques set of analyses was used, in order to characterize both the sulphided active phase (TEM, XPS, IR-CO, model molecules test) and acidity (IR-CO, model molecules tests). We also confirm that support texture was not modified by the incorporation of silicon.Grafting procedure allows to both control textures but also hydrogenation rate, the one being assessed by toluene hydrogenation. In addition, acidity strength of the catalysts was slightly increased. Nevertheless, it remains obvious that nickel disponibility (i.e. in surface of the catalyst) must be affected with higher concentration of silicon. It leads to significant modifications in the active phase features. As a matter of fact, NiMoP catalysts with same texture, same hydrogenating power, but also different level of acidity reveal no change in conversion (χ370+ and χ540+ and HDAsC7) or hydrogenation performance (HDS, HDV). Nevertheless, it is proved that acidity can enhance the cracking of aliphatic chains of asphaltenes without increasing their aromaticity. It could provide an original way of cracking of asphaltenes different from the well known thermal mechanisms. This new way of transformation opens the way to a complete change of reactivity over the whole HDT processes.

Application of nanocatalytic systems for deep processing of coal and heavy petroleum feedstock

The specific features of the catalysis of deep processing (hydrogenation and gasification) of coal and hydroconversion of heavy petroleum feedstock are considered. It has been shown that it is reasonable to use new catalyst forms and catalyst introduction methods for the processing of these raw materials in view of their specific composition and properties (large size of molecules, thermal instability, and the presence of inorganic compounds in the feedstock). In particular, a dispersion of nanosized spherical particles of MoS2 in a liquid hydrocarbon medium is an effective catalyst for the coal hydrogenation and heavy-oil hydrocon-version processes. Gaseous alkali metal hydroxides have been proposed for the gasification of solid fuels. The mechanisms of the formation of catalyst systems and some of their properties are discussed.

Stepwise Structural Characterization of Asphaltenes during Deep Hydroconversion Processes Determined by Atmospheric Pressure Photoionization (APPI) Fourier Transform Ion Cyclotron Resonance (FT-ICR) Mass Spectrometry

The compositional analysis (speciation) of heavy oil products is a key step to improve our understanding of hydrotreatment processes and reaction mechanisms. Thus, detailed characterization of polar fractions, such as asphaltenes, should be considered. Here, we employ atmospheric pressure photoionization Fourier transform ion cyclotron mass spectrometry to monitor the evolution of the asphaltene hydrocarbon and sulfur families in deep hydrotreatment processes (fixed and ebullated beds). The results suggest that the complexity of the asphaltenic fractions (in terms of chemical polydispersity) is drastically lowered with increased process severity. In either fixed or ebullated beds, the evolution of the sulfur species is quite similar in class composition, aromaticity (DBE/carbon number ratio), and polycondensation (DBE). The compositional changes are marked by a drastic increase in aromaticity to highly polycondensed dealkylated aromatic structures. Asphaltene disaggregation followed by a dealkylation of t...

Towards Comprehensive Hydrocarbons Analysis of Middle Distillates by LC-GCxGC

The detailed characterization of middle distillates is essential for a better understanding of reactions involved in refining processes. Owing to a higher resolution power and an enhanced sensitivity, but especially to a group-type ordering in the chromatographic plane, comprehensive two-dimensional gas chromatography (GCxGC) offers unsurpassed characterization possibilities for petroleum samples. However, GCxGC fails to totally discriminate naphthenes from unsaturates occurring in hydrotreated diesel samples. This article aims at promoting the implementation of LC-GCxGC for the quantitative determination of hydrocarbon distribution in middle distillates, including naphthenes. In this configuration, liquid chromatography (LC) enables the separation of hydrocarbons into two fractions (viz., saturated and unsaturated) before the subsequent analysis of each fraction by GCxGC. In this paper, the choice of GCxGC conditions in order to achieve the separation and identification of hydrocarbons by chemical class is discussed; under these conditions, naphthenes are separated according to the number of saturated rings. For the first time, the presence of di-, tri-, and tetra-naphthenes resulting from the hydroconversion of aromatics can clearly be evidenced. A quantitative procedure for the determination of the distribution of hydrocarbons, including the distribution of naphthenes according to the number of saturated rings, is also proposed and discussed in detail. LC-GCxGC is found to provide an unequalled degree of information that will widely contribute to a better understanding of hydroconversion processes.

Catalytic Properties of Single Layers of Transition Metal Sulfide Catalytic Materials

Single layer transition metal sulfides (SLTMS) such as MoS2, WS2, and ReS2, play an important role in catalytic processes such as the hydrofining of petroleum streams, and are involved in at least two of the slurry‐catalyst hydroconversion processes that have been proposed for upgrading heavy petroleum feed and other sources of hydrocarbon fuels such as coal and shale oils. Additional promising catalytic applications of the SLTMS are on the horizon. The physical, chemical, and catalytic properties of these materials are reviewed in this report. Also discussed are areas for future research that promise to lead to advanced applications of the SLTMS.

Factorial design for the evaluation of the influence of preparation parameters upon the properties of dispersed molybdenum sulfide catalysts

Oil-soluble molybdenum precursors such as naphthenates are used as additives for the hydroconversion of heavy petroleum residues. Under the conditions of hydroconversion processes, molybdenum naphthenate yields molybdenum sulfide and, simultaneously, a carbonaceous phase is produced. The complex solid resulting from the interaction of these phases exhibits a high surface area, outstanding catalytic activity and stability. These properties are attributed to the presence of the carbon phase. The present work consists in a systematic investigation of the influence of compositional and physical parameters upon the composition, surface area and catalytic properties of dispersed molybdenum sulfides generated in a pure synthetic medium representative of crude oil. A factorial design, based upon previous results concerning the nature of the catalytic precursor, has been elaborated. The following parameters have been considered in the present study: nature of the solvent (aromatic or aliphatic), nature of the sulfiding reagent, temperature, concentration of the precursor, residence time. It has been established that the nature of the solvent (aromatic or aliphatic) and the sulfiding reactant had a significant influence on the properties. An interactive effect between the nature of the sulfiding reagent and the concentration of the precursor has been evidenced.

Hydroconversion of resids with dispersed molybdenum catalysts derived from phosphomolybdates

Phosphomolybdic acid (PMA) and cobalt, nickel and potassium phosphomolybdates have been found very active catalyst precursors for the conversion of coal- and petroleum-derived resids when they are impregnated onto coal and Al 2O 3. They are mostly stable up to 400–450°C in the presence of He and H 2, but significant change in stability occurs in the presence of H 2S, transforming these materials into an active form of catalyst. Their solubility in water provides highly dispersed catalysts in the reaction media. PMA and these bimetallic materials were tested at the concentration of 15, 150 and 1500 mg Mo per kg feed for reaction times of 30 and 90 min, and compared to a commercial NiMo/Al 2O 3 catalyst (AKZO-60). In the 30 min reactions, increasing Mo concentration did not provide a significant improvement in resid conversions compared to the non-catalyzed case. However, in the 90 min reactions, improvements were observed in conversion of coal and Mayan resids to distillate boiling below 525°C. The results indicate that thermal reactions play an important role in the 30 min reactions, and catalytic reactions resulting in increased resid conversions become more important in the 90-min reactions. Higher conversions with nickel phosphomolybdate supported on Al 2O 3 were observed with Mayan resid compared with coal resid. Nickel phosphomolybdate has been found to have promising catalytic activity for hydroconversion processes.

Transformation of phosphomolybdates into an active catalyst with potential application in hydroconversion processes

Conversion of phosphomolybdates under typical hydroprocessing conditions were investigated since they are known to be transformed into active catalysts for hydroconversion processes. This paper reports the reaction of phosphomolybdic acid (PMA), nickel phosphomolybdate (NiPM), cobalt phosphomolybdate (CoPM) and potassium phosphomolybdate (KPM) in He, H 2 and H 2S–H 2 at temperatures up to 450°C. The phosphomolybdates sulfided at 300, 350, 400 and 450°C were analyzed by FT-IR, Raman, XRD and XPS. These phosphomolybdates are stable in both He and H 2 until they lose their crystalline water. However, in the presence of H 2S, sulfur is incorporated into the structure rapidly. Although sulfur incorporation up to 300°C is low, it increases considerably as the sulfidation temperature increases. The S/Mo ratios in the sulfided materials show that sulfur uptakes into the structures are less than two for PMA, NiPM and CoPM whereas it was 2.1 for KPM at a sulfidation temperature of 450°C. Spectroscopic analyses suggest that the products from the sulfidation of phosphomolybdates may be NiO or CoO, MoS 2, P 2O 3 or K 4P 2O 7 and a molybdenum oxide (MoO x ) or a molybdenum oxysulfide (MoO x S y ), The oxidation state of Mo decreased to 3.8+, 4.8+, 4.6+ and 5.4+ at 300°C, and 3.8+, 4.2+, 4.2+ and 4.4+ at 450°C for the sulfided PMA, NiPM, CoPM and KPM materials, respectively. Results indicate that the active catalyst in hydroconversion processes does not resemble the Keggin anion. The active catalysts may be a mixed oxisulfides and some bulk metal sulfides.

99/03997 Dispersed anion-modified metal-promoted iron oxide catalysts for hydrotreatment and hydroconversion processes: Pradhan, V. R. et al. US 5,866,501 (Cl. 502-338; B01J23/74), 2 Feb 1999, Appl. 609,759, 23 Feb 1996, 13 pp

99/03997 Dispersed anion-modified metal-promoted iron oxide catalysts for hydrotreatment and hydroconversion processes: Pradhan, V. R. et al. US 5,866,501 (Cl. 502-338; B01J23/74), 2 Feb 1999, Appl. 609,759, 23 Feb 1996, 13 pp

Modelling and simulation of a multiphase fluidized bed reactor by variational principles

This paper shows the study of a computational fluid dynamics approach through the investigation and evaluation of the intrinsic characteristics of the optimization associated with the variational principle method when applied to a multiphase fluidized bed reactor modelling and simulation operating in a slurry bubble column mode. The optimization criterion associated in the method is based on the minimization of the amount of energy. The variational method has advantages in modelling and fitting parameters (constants) of equations in the critical regions of the flow, where other methods may not give good results, and regions under the influence of the equipment wall or other disturbences. The disadvantage of this method is that there is no general method applicable in all processes, just for particular cases. The type of reactor evaluated is employed in hydroconversion and hydrotreatment processes. There are few experimental results available in the literature for real situations. The simulated computational results are compared with the experimental results from the literature of an fluidized system formed by water-air-glass spheres. Also, computational results are compared with the result obtained for a hydroconversion reactor solved by means of the finite volume method. The results obtained show that the variational method is capable of simulating a multiphase fluidized bed reactor as well as other methods. This show that it is possible to explore the optimization characteristics of the variational principles.