Coker Gas Oil Research Articles

Production of Marine Fuel Components by Extraction Treatment of Vacuum Gasoils and Gasoils from Secondary Oil Refining Processes (A Review)

Data on the extraction of aromatic hydrocarbons and of sulfur- and nitrogen-containing compounds from model systems with selective solvents, ionic liquids, and deeply eutectic solvents are discussed. The results of the extraction treatment of light and heavy vacuum gasoils and of visbreaker and delayed coker gasoils are presented. The extraction treatment of vacuum gasoils and gasoils from secondary oil refining processes allows the sulfur content of the raffinate to be reduced to less than 0.5 wt %, which meets the requirements to marine fuels used in open sea. The treatment of visbreaker and especially delayed coker gasoils is considerably more efficient than that of vacuum gasoils. The degree of removal of nitrogen-containing components and polyaromatic compounds with dimethylformamide or N-methylpyrrolidone as an extractant is higher than that of sulfur-containing compounds.

Application of advanced correlative approaches to modeling hydrogen solubility in hydrocarbon fuels

In petroleum and petrochemical refineries, having precise knowledge regarding H2 solubility in hydrocarbon fuels and feedstocks is critical. In this study, the hydrogen solubility in hydrocarbon fuels was estimated using genetic programming (GP) and group method of data handling (GMDH), two exemplary robust advanced models for generating correlation. To do this, 445 observations derived from labratory findings on hydrogen solubility in 17 different hydrocarbon fuels such as bitumen, atmospheric residue, heavy coking gas oil, heavy virgin gas oil, light virgin gas oil, straight run gas oil, shale fuel oil, dephenolated shale fuel oil, diesel, hydrogenated coal liquid, coal liquid, and coal oil, over a large interval of P- operating pressures and T-temperatures were collected. Temperature, pressure, as well as density at 20 °C, molecular weight, and weight percentage of carbon (C) and hydrogen (H) in hydrocarbon fuels, were used as input parameters in developing robust correlations. The outcomes showed the GMDH approach is more precise compared to the GP, with a root mean square error (RMSE) of 0.053302 and a determination coefficient (R2) of 0.9641. Additionally, sensitivity analysis showed that pressure, followed by temperature and H (wt%) of hydrocarbon fuels, has the greatest impact on hydrogen solubility in hydrocarbon fuels. Ultimately, the Leverage method's results suggested that the GMDH model could be relied on to predict hydrogen solubility in hydrocarbon fuels.

ЭКСТРАКЦИОННАЯ ОЧИСТКА ТЯЖЕЛОГО ГАЗОЙЛЯ ЗАМЕДЛЕННОГО КОКСОВАНИЯ С ИСПОЛЬЗОВАНИЕМ ЭКСТРАКЦИОННОЙ СИСТЕМЫ N-МЕТИЛПИРРОЛИДОН – ГЕПТАН

The article presents the results of the extraction purification of heavy delayed coking gas oil with mass ratios of N-methylpyrrolidone with 2 % mas water to raw materials as 0.5 : 1, 0.75 : 1, 1 : 1, and in the presence of heptane at mass ratio to raw materials as 0.3 : 1 and temperature of 40 оC. It was found that the introduction of heptane into the extraction system with N-methylpyrrolidone leads to an increase in the yield of raffinate due to an increase in the selectivity of the release of polyaromatic hydrocarbons. However, due to the presence in the gas oil of delayed coking of sulfur compounds of not only aromatic nature, but also saturated thiacyclanes and dialkylsulfides forming systems close to ideal with heptane, the efficiency of gas oil desulfurization decreases.

Нефтепродукты для северных территорий на основе процесса замедленного коксования

Possible risks of summer and inter-season fuel overproduction at the Russian Federation oil refineries are reviewed. Comprehensive analysis of properties of coking light gas oil narrow fractions hydrotreated at hydrogen pressure of 80 atm is conducted. Dependences of changes in density, cloud point, chilling point, content of aromatic hydrocarbons, sulfur and nitrogen on weighting of fraction composition are considered. Based on the received data the components of jet fuel, winter and summer diesel fuel were compounded from narrow fractions. Received blends are analyzed for compliance with the requirements of corresponding GOSTs. The possibility to receive jet fuel, winter and summer diesel fuel from light coking gas oil at hydrogen pressure of 80 atm is shown.

Experimental investigation of sulfur distribution and yields of liquid fuel and petroleum coke produced by thermal cracking of vacuum residues

In the present work, an experimental study was conducted to investigate the sulfur distribution in the products during thermal degradation of vacuum residues at different operating conditions. In this regard, three vacuum residues with different sulfur contents were selected. The effects of main operating conditions such as pressure and temperature on products yields and properties were studied. The results show that for sulfur distribution, which is indicated as the ratio of the amount of sulfur in each product to the initial mass of sulfur in the feed, increasing temperature will be followed by increased sulfur distribution in liquid fuel and reduced sulfur distribution in petroleum coke. Furthermore, effects of reaction temperature on yields of light coker gasoil (150–350 °C) as well as heavy coker gasoil (350–500 °C), as the dominant fractions of thermal cracking products, were evaluated using simulated distillation method.

Deep hydrodesulfurization of gas oils with high sulfur content: Experiment and kinetic modeling

The hydrodesulfurization of straight-run gas oils (SRGO-HS) with high content of sulfur (about 2 wt%) and its mixture with light coker gas oil (CGO) has been studied over CoMo/Al2O3 catalyst using a trickle bed down-flow reactor at the 335–365 °C, H2/HC − 300 Nm3/m3, LHSV − 0.8–2.5 h−1 and 3.5–5.1 MPa. The possibility of ultra-low sulfur diesel (<10 ppmS) production using feedstocks with sulfur content exceeding 2 wt% was demonstrated under conditions simulating industrial one. To predict the effect of process parameters on the amount of sulfur in products four kinetic models with different insight into the reactivity of individual S-containing compounds were considered. The first model is simplified kinetics based on power law rate equations, taking into account overall sulfur content, the second group includes LHHW type rate equations. The models 3 and 4 take into consideration the difference in the reactivity of sulfur-containing components. Model 3 classifies the total sulfur into two subgroups Se (easy reactive compounds) and Sr (refractory sulfur compounds - dibenzothiophene and its derivatives). In Model 4 the group Sr is divided into three more subgroups. Kinetic rate parameters i.e. frequency factors, apparent activation energies, and adsorption enthalpies, were estimated by fitting the experimental data obtained using the SRGO-HS/CGO feedstock to the models. All kinetic models predicted the experimentally determined conversions of sulfur with a relatively good accuracy (±20%). The kinetic models were verified by comparing the simulation results with the experimental data obtained using the other oil fractions (SRGO-LS) with lower content of sulfur (1.05 wt%). A better agreement was observed between the experiments and prediction by models 3 and 4.

Synthesis of mesoporous TiO2-Al2O3 composites supported NiW hydrotreating catalysts and their superior catalytic performance for heavy oil hydrodenitrogenation

Mesoporous TiO2-Al2O3 composites with different Ti/Al molar ratios were successfully synthesized via pre-hydrolysis co-precipitation method and the corresponding NiW supported hydrotreating (HDT) catalysts were prepared via incipient wetness co-impregnation method. The effects of Ti modification on the physicochemical properties of the prepared supports and catalysts were determined by the characterization techniques such as XRD, FTIR, N2 physical adsorption–desorption, SEM-EDS, ICP-OES, NH3-TPD, H2-TPR, HRTEM and XPS. Finally, quinoline, indole and coker gas oil (CGO) were used respectively as probes to investigate the Ti modification on the hydrodenitrogenation (HDN) performances of the corresponding catalysts. The results show that the TiO2-Al2O3 samples synthesized by the pre-hydrolysis co-precipitation method achieved the level of molecular composition, and the crystalline structures, pore properties and acidity properties of the TiO2-Al2O3 supports varied with the Ti/Al molar ratios. Ti modification can modulate the interaction between the active metals and the supports (MSI), and promote the formation of more so-called “type II” NiWS active phases. Furthermore, the existence of Ti3+ species in catalysts NiW/TA1 and NiW/TA2 enhanced the sulfidation degrees of active metals and weakened the bond energy between the active metals and sulfur atoms and further promoted the formation of more coordinatively unsaturated sites (CUS). The catalytic assessment results show that the HDN activities of the catalysts were effectively improved after Ti modification and the improvement was largely due to the promotion of the cleavage of the C(sp3)-N bond of basic nitrides and the C(sp2)-N bond of non-basic nitrides. The NiW/TA1 catalyst exhibited the highest performance in the HDT process of heavy oil, with a 15.8% and 12.4% improvement in HDN rate and hydrodesulfurization (HDS) rate compared with the unmodified catalyst, respectively, which was mainly attributed to its suitable pore properties, moderate MSI, large number of CUS, moderate stacking and highest active metal sulfidation degree of the active phase.

Изменение свойств узких фракций в процессе гидроочистки легкого газойля коксования

Currently, the main products of the delayed coking plant in the Russian Federation (after hydrotreating) are gasoline and diesel fuel summer. The paper presents the results of a study of the properties of narrow fractions of coking gas oil and hydrotreated coking gas oil, which showed the prospect of organizing production based on the coking process of more marginal aviation kerosene and winter diesel fuel. The separation of products into narrow 20 degree fractions was carried out on an automatic distillation unit AUTOMAXX 9100. The dependences of nitrogen, sulfur, aromatics, density, and low-temperature properties on the boiling temperatures of narrow fractions of the composition of light coking gas oil and hydrotreated light coking gas oil have been studied. Analysis of the properties of narrow fractions of hydrotreated light coking gas oil has shown the theoretical possibility of obtaining fractions of jet fuel and winter diesel fuel on its basis, instead of summer diesel fuel.

Hydrodesulfurization reactions group kinetics of “vacuum gas oil–deasphalted vacuum residues–heavy coker gasoil” feedstock in the presence of a Ni6–PMonW12-n/γ-Al2O3 catalysts

Hydrodesulfurization reactions group kinetics of “vacuum gas oil–deasphalted vacuum residues–heavy coker gasoil” feedstock in the presence of a Ni6–PMonW12-n/γ-Al2O3 catalysts

Nitrogen compounds removal from oil-derived middle distillates by MIL-101(Cr) and its impact on ULSD production by hydrotreating

Oil-derived middle distillates (straight-run gas oil and mixture with light cycle oil and coker gas oil) for Ultra-Low Sulfur Diesel (ULSD) production by HyDroTreating (HDT) were pretreated by selective Nitrogen Organic Compounds (NOC) adsorption. Highly crystalline Metal-Organic Framework (MOF) MIL-101(Cr) prepared with propylene oxide (proton scavenger) as textural improver was used to that end. MOF was characterized by N2 physisorption, X-ray diffraction, thermal analysis, infrared, Raman and UV-vis spectroscopies, and electron microscopy (SEM and HR-TEM). NOC removal was carried out at room temperature and atmospheric pressure, the adsorbent being easily regenerable under mild conditions. Extruded MOF efficiently removed NOC from real feedstocks to concentrations ~ 80 ppm which allowed ULSD production at much milder conditions to those used during pristine feedstocks HDT. Operating temperature could be significantly diminished (from 350 to 330 °C, at 56 kg cm−2 (5.77 MPa), LHSV = 1.5 h−1, H2/oil = 2500 ft3 bbl−1 (445 m3 m−3)) which could notably prolong cycle life of NiMo/Al2O3 formulation used.

Изучение изменения фракционного состава при гидроочистке под высоким давлением легкого газойля коксования

Slavneft-YANOS PJSC plans to commission delayed coking unit in 2025, and the key task is to increase the depth of oil refining and increase the share of high-margin petroleum products. As a result of evaluating the change of 95% of the diesel fuel boiling point during hydrotreatment at high hydrogen pressure, it was concluded that it is possible to expand the fractional composition of light coker gasoil at expense of heavy coker gasoil.

Synthesis of sulfur-doped porous carbon from heavy coker gas oil and its application in CO2 capture

Elemental sulfur is used to cross-link heavy coker gas oil (HKGO) with only 0.44 wt% olefinic hydrogen content in the absence of solvent; subsequent pyrolysis yields sulfur-doped porous carbon with Brunauer–Emmett–Tell (BET) surface area (s.a.) around 1714–1785 m2 g−1.

Hydrogen-donated thermal upgrading of Venezuela extra-heavy oil: identifying the role of hydrogen donor

A natural hydrogen donor, i.e., a subfraction of the coker gas oil, was used in thermal upgrading of the Venezuela extra-heavy oil. The role of hydrogen donor was quantitatively studied by a combination of thermogravimetric analysis and differential scanning calorimetry. The hydrogen donation was clearly evidenced and reliably evaluated by comparing the experimental and calculated thermal parameters. The mutual interactions between the heavy oil and the hydrogen donor extended the coke induction period (from 19 to 25 min), inhibited the thermal evaporation of the hydrogen donor, and resulted in a stronger endothermic effect in the pyrolysis stage.

Production of Low -Sulfur Marine Fuel

This paper presents the results of testing a catalyst system developed for the demetallization and desulfurization of vacuum gas oil and heavy coker gas oil mixture at a pressure of 6 MPa, a temperature of 360-370°C, and a feed volumetric rate of 1 h-1 for obtaining a product having a sulfur content of 0.05 wt.%. The composition of RMB 30 marine fuel is developed with the application of a distillate fraction obtained from secondary processes and a depressant-dispersant additive in order to bring the pour point to the requirements of GOST32510-2013.

Effect of operating conditions on HDS of CGO blended middle distillate

Abstract The utilization of heavier stream of petroleum hydrocarbon such as coker gas oil (CGO) via diluting with straight run gas oil (SRGO) (blended feed: SRGO and CGO; 30/70) in order to enhance the middle distillate pool of fuel (heating oil, diesel fuel, jet fuel, and kerosene). Usually, CGO fraction has a propensity to retain refractory sulfur, nitrogen and aromatics compounds. The former two elements are mainly associated with the aromatic sulfur and nitrogen compounds (i.e., refractory). Hence, a systematic study was conducted with the variation of hydrotreating operating conditions to convert sulfur, nitrogen, and aromatic compounds. The performance was carried out in a fixed bed bench-scale reactor unit, using a commercial CoMo/Al2O3 (catalyst X) catalyst after sulfidation. The CGO has a significantly higher amount of nitrogen, aromatic, and refractory sulfur compounds than that of SRGO, which makes this blend more challenging. Hence, the operating conditions have been investigated to remove sulfur and nitrogen compounds and improve the cetane index during the hydroprocessing. The variation in operating conditions is to achieve 450 ppmS in the hydrotreated product using CGO and SRGO blend as a feedstock. The conversion of sulfur and nitrogen compounds indicated that hydrodesulfurization (HDS) is selectively higher than hydrodenitrogenation (HDN) where hydrogenation played a crucial role in their selectivities at high conversion. The hydrogenation function also relates to the cetane index that decreases with increasing aromatic content. The degree of inhibition (HDS and cetane index) depends on the feed composition (nitrogen and aromatics) that consumes a large amount of hydrogen. Conclusively, beyond 90% of HDS conversion, most of the sulfur compounds are refractory, which requires a stronger hydrogenation function to remove steric-hindrance from the refractory molecule.

Effect of Retarding Components on Heavy Oil Catalytic Cracking and Their Corresponding Countermeasures

Heavy oil could be classified into two parts: one is the easy cracking part, which is the main source of liquid hydrocarbon transportation fuels and industrial chemicals, and the other is the refractory cracking part, which is failed to be cracked by the present technologies and has negative effects on upgrading. Therefore, the efficient method to obtain a higher conversion of heavy oil is needed for the heavy oil processing industry. Coker gas oil (CGO), used as an example of heavy oil, is supposed to be hard to process during fluid catalytic cracking (FCC). The structural information in the molecular level of basic nitrogen compounds, nonbasic nitrogen compounds, and condensed aromatics in feedstock and liquid products from FCC was investigated. The coked catalysts in the catalytic cracking reaction of CGO were characterized. The results showed that these compounds, especially basic ones, are more difficult to crack, which are preferentially chemisorbed on the surface of the catalyst leading to less acid sites for other easy cracking hydrocarbons and the decrease of the activity of catalysts. Physical solvent removal and chemical catalytic adsorption were used to pretreat heavy oil, and the result indicated that either physical solvent removal or chemical catalytic adsorption is a good way to avoid the retarding effects of refractory cracking components, and better product distributions can be obtained.

Influence of the Pore Structure of a Catalyst for Demetallization of Petroleum Feedstock on the Process Results

Demetallization of a mixture of vacuum gas oil with heavy coker gas oil on CoMo/γ-Al2O3 catalysts with different pore structures was studied, and the influence of the catalyst pore structure on the process results was demonstrated. For the demetallization catalysts to be effective, their pore size should be restricted not only from below but also from above. When using samples with broad pores, effects of the hydrodesulfurization and hydrodemetallization inhibition can arise owing to adsorption of supramolecular structures of heavy residues, in particular, of asphaltenes.

Study of the Influence Exerted by Addition of Coker Gas Oil to Straight-Run Gas Oil on the Process of Hydrotreating in the Presence of CoMo/Al2O3 Catalyst

Behavior of the CoMo/Al2O3 catalyst was experimentally studied in the course of hydrotreating of a straight-run gas oil with high content of sulfur (>2 wt %) and its mixture (up to 30 wt %) with light coker gas oil in the temperature range 335–365°C and liquid hour space velocity of feedstock deliver of 0.8–2.5 h−1. It was shown that addition of gas oil to the straight-run gas oil in hydrotreating under the conditions corresponding to the working conditions of the existing domestic hydrotreating installations [L-24-5, L-24-6, L(Ch)-24-7] has oppositely directed effects, depending on temperature and feedstock delivery rate. For example, the additives lead in the temperature range 335–350°C to an increase in the content of sulfur in hydrotreating products. At a temperature of 365°C, better sulfur-related parameters are reached in processing of feedstocks containing light coker gas oil. The observed dependences are accounted for as follows: the dilution of the straight-run gas oil by addition of light coker gas oil leads to a decrease in the content of difficulty converted sulfur-containing compounds, but makes larger the content of nitrogen-containing compounds inhibitors of the hydrodesulfurization reaction, the influence of which on the reaction rate becomes weaker with increasing temperature.

Introduction of heavy diesel fractions of primary and secondary refining processes in the production of light oil products

In order to increase the yield of light oil products, it is proposed to use the following heavy fractions obtained by JSC Angarsk Petrochemical Company in the course of oil refining as components for lowviscosity marine fuel: light coker gas oil, heavy diesel fractions removed from vacuum columns of primary-oilrefining units, heavy diesel fractions obtained from atmospheric columns and vacuum distillates of various fractional compositions. The results of tests conducted according to standardised procedures showed that an introduction of depressor (VES-410D) and depressor-dispersing (VES-410DDP) additives into the components of low-viscosity marine fuel significantly depresses the pour points of these components. In this article, the authors propose depressor and depressor-dispersing additives, as well as determine their optimal concentrations for high depression rates allowing the pour point to be reduced to a standardised value for the compound composition using heavy diesel fractions of primary and secondary refining processes. In addition, the authors determined the optimal basic formulation of the low-viscosity marine fuel including products of primary and secondary oil processing with heavy fractional composition. A number of commercial depressordispersing additives were tested using this basic formulation in order to explore alternatives and study the additives market. Five of these commercial additives provide good chemmotological indicators for lowviscosity marine fuel (including low-temperature characteristics, filterability and sedimentation stability) and can be recommended for further industrial use. The optimal composition of the mixtures was modelled on the basis of the obtained data, allowing a determination of the most rational technology for producing low-viscosity marine fuel in conformity with regulatory requirements.

Molecular-Level Insights into Coker/Straight-Run Gas Oil Hydrodenitrogenation by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

This paper aims to understand the reactivity of different nitrogen species during the catalytic hydrodenitrogenation (HDN) of a mixture of straight-run gas oil and coker gas oil. Effluents at different HDN conversions were analyzed by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR/MS), with electrospray ionization (ESI). Positive ESI (ESI(+)) allows a selective ionization of basic nitrogen compounds, whereas negative ESI (ESI(−)) leads to selective ionization of neutral nitrogen compounds. FT-ICR/MS in ESI(+) or (−) mode generates distributions of the nitrogen compounds in the basic and neutral class, respectively, according to their carbon number and double bond equivalent (DBE), which is related to the degree of aromaticity and the number of rings. The evolution of the DBE distribution and the carbon number distribution as a function of HDN conversion gives rich information concerning the main reaction pathways and the reactivity of different nitrogen species. For the basic compound...