Rosen Dinkov

LUKOIL Neftohim Burgas JSC · Head of quality branch/Chief process engineer

A comprehensive investigation of a highly complex petroleum refinery (Nelson complexity index of 10.7) during the processing of 11 crude oils and an imported atmospheric residue replacing the design Urals crude oil was performed. Various laboratory oil tests were carried out to characterize both crude oils, and their fractions. The results of oil l...

An expected increase in the demand for aviation transport service will result in the deterioration of the environment and human health, respectively, due to extra greenhouse gas (GHG) emissions. Concerns from EU institutions about the issue have led to legislation initiatives and, later, to development of Regulation (EU) 2023/2405 for the reduction...

Citation: Shiskova, I.; Stratiev, D.; Tavlieva, M.; Nedelchev, A.; Dinkov, R.; Kolev, I.; van den Berg, F.; Ribagin, S.; Sotirov, S.; Nikolova, R.; et al.

The compatibility of constituents making up a petroleum fluid has been recognized as an important factor for trouble-free operations in the petroleum industry. The fouling of equipment and desalting efficiency deteriorations are the results of dealing with incompatible oils. A great number of studies dedicated to oil compatibility have appeared ove...

The vacuum residue hydrocracker naphtha (VRHN) is a chemically unstable product that during storage changes its colour and forms sediments after two weeks. It cannot be directly exported from the refinery without improving its chemical stability. In this research, the hydrotreatment of H-Oil naphtha with straight run naphtha in a commercial hydrotr...

The refractive index is an important physical property that is used to estimate the structural characteristics, thermodynamic, and transport properties of petroleum fluids, and to determine the onset of asphaltene flocculation. Unfortunately, the refractive index of opaque petroleum fluids cannot be measured unless special experimental techniques o...

Twelve crude oil blends prepared from seven individual crude oils and an imported atmospheric residue were characterized through a true boiling point (TBP) distillation analysis and their density. When comparing the measured TBP fraction yields with those estimated through the application of the additive blending rule, it was found that, for four c...

The Urals and Siberian vacuum residues are considered difficult to process in the ebullated bed hydrocracking because of their increased tendency to form sediments. Their achievable conversion rate reported in the literature is 60%. Intercriteria analysis was used to assess data from a commercial vacuum residue hydrocracker during processing blends...

The exactitude of petroleum fluid molecular weight correlations affects significantly the precision of petroleum engineering calculations and can make process design and trouble-shooting inaccurate. Some of the methods in the literature to predict petroleum fluid molecular weight are used in commercial software process simulators. According to stat...

Forty-eight crude oils with variations in specific gravity (0.782 ≤ SG ≤ 1.002), sulphur content (0.03 ≤ S ≤ 5.6 wt.%), saturate content (23.5 ≤ Sat. ≤ 92.9 wt.%), asphaltene content (0.1 ≤ As ≤ 22.2 wt.%), and vacuum residue content (1.4 ≤ VR ≤ 60.7 wt.%) were characterized with HTSD, TBP, and SARA analyses. A modified SARA analysis of petroleum t...

165 crude oils with viscosity, density, and molecular weight variation in the range 0.54 – 24135cP; 0.746 – 1.016 g/cm³; 117–579 g/mol respectively were examined for viscosity prediction using eight available in the literature models and three more, developed in this work models. The best empirical model was that of Sinha et al., 2020 with % AAD (a...

The intercriteria analysis developed on the base of intuitionistic fuzziness and index matrices was applied to evaluate processing data of the LUKOIL Neftohim Burgas H-Oil ebullated bed vacuum residue hydrocracker with the aim of revealing the reasons for increased fouling registered during the 3rd cycle of the H-Oil hydrocracker. It was found that...

The use of hydrocracked and straight-run vacuum residues in the production of road pavement bitumen requires a good understanding of how the viscosity and softening point can be modeled and controlled. Scientific reports on modeling of these rheological properties for hydrocracked and straight-run vacuum residues are scarce. For that reason, 30 str...

This study analyzes the performance of the LUKOIL Neftohim Burgas (LNB) fluid catalytic cracking unit (FCCU) after commissioning of the H-Oil vacuum residue hydrocracker. It makes a parallel with the performance of the LNB FCCU experiencing high catalyst losses long before the commissioning of the H-Oil hydrocracker, revealing that the operation of...

This paper summarises the experience gained in LUKOIL Neftohim Burgas refinery with the production of road asphalt from blends containing straight run and hydrocracked vacuum residues. The effect of diluting of the bitumen blends with fluid catalytic cracking gas oils and H-Oil heavy vacuum gas oil (HVGO) and straight run vacuum gas oil (SRVGO) is...

Four nonlinear regression techniques were explored to model gas oil viscosity on the base of Walther's empirical equation. With the initial database of 41 primary and secondary vacuum gas oils, four models were developed with a comparable accuracy of viscosity calculation. The Akaike information criterion and Bayesian information criterion selected...

Evolution of ebullated bed industrial hydrocracking atmospheric and vacuum tower bottoms from 2015 (start-up) until now is analysed in terms of applicability of residue for production of road pavement bitumen. Increased conversion in this money-maker (cheap vacuum residue feed and marginal naphtha and gasoil products) unit is in line with the drivi...

Three H-Oil gas oils, heavy atmospheric gas oil (HAGO), light vacuum gas oil (LVGO), heavy vacuum gas oil (HVGO), and two their blends with hydrotreated straight run vacuum gas oils (HTSRVGOs) were cracked on two high unit cell size (UCS) lower porosity commercial catalysts and two low UCS higher porosity commercial catalysts. The cracking experime...

Four straight run vacuum residual oils (SRVRO) and five H-Oil hydrocracked vacuum residual oils (H-Oil VTB) and their blends were oxidized in a laboratory autoclave reactor. It was found that the addition of H-Oil VTB to the SRVRO increases the oxidation rate of the SRVRO, which leads to a higher rate of asphaltenes formation, and subsequently high...

10 gas oils and one deasphalted hydrocracked vacuum residue obtained from ebullated bed vacuum residue hydrocracking have been cracked in a laboratory advanced catalyst evaluation unit on a commercial fluid catalytic cracking (FCC) catalyst. It was found that the 11 secondary heavy oils obey second order reaction kinetics. The relations between gas...

H-Oil residual oils obtained during processing of vacuum residua originating from nine crudes and one imported atmospheric residue in LUKOIL Nefto-him Burgas H-Oil hydrocracker were diluted with high saturate lower sulfur distillates, and high aromatic FCC gas oils. The content of the sediments formed in H-Oil hydrocracker streams can be increased...

The LUKOIL Neftohim Burgas vacuum residue hydrocracking has increased the vacuum residue conversion from 55 to 93% as a result of a proper feed selection, optimal catalyst condition, and the use of a Mo nanodispersed catalyst. It was found that the feed colloidal instability index estimated from the feed saturates, aromatics, resins, and asphaltene...

Rheological property viscosity of H-Oil Unconverted hydrocracked vacuum residue (HCVR) has been followed from the start-up of the H-Oil hydrocracker in LNB refinery in 2015 till June of 2020. It has varied by a factor of ten while the vacuum residue conversion has varied between 58 and 88%. Increasing H-Oil vacuum residue conversion is associated b...

The restrictive factor for maximisation of Unconverted vacuum tower bottom (UVTB) from ebullated bed hydrocracking process – H-Oil technology in bitumen production is its low resistance to hardening, determined by using a Rolling thin film oven (RTFO). The limitation in LUKOIL Neftohim Burgas (LNB) industrial production is up to 37% UVTB in blends...

Investigation on the properties of fluid catalytic cracking (FCC) slurry oil (SLO) at different conversion levels and the impact of FCC SLO processing on H-Oil vacuum residue hydrocracking performance and on the subsequent performance of the FCC unit was carried out in this paper. Analysis of FCC SLO samples taken at different FCC conversion levels...

26 vacuum residual oils (VROs) were characterised and hydrocracked in the LUKOIL Neftohim Burgas H-Oil ebullated bed unit. The VRO properties: contents of saturates, sulphur, nitrogen, and asphaltenes were found to affect both feed reactivity and its propensity to form sediments during hydrocracking. The saturates, nitrogen and asphaltenes contents...

The results of hydrocracking of several vacuum residual oils obtained in a pilot plant, in a laboratory Robinson Mahoney reactor unit, and in the commercial LUKOIL Neftohim Burgas ebullated bed H-Oil hydrocracker were discussed. It was found that during increasing of vacuum residue conversion by decreasing liquid hourly space velocity (LHSV) the as...

This study focuses on investigating the conversion behaviour of vacuum residue and blends with heavy VGO (480–540°C) and atmospheric residue (340°C+), three fractions originating from the same Russian export blend crude oil (REBCO), in a laboratory ebullated bed hydrocracking pilot plant unit and in the LUKOIL Neftohim Burgas commercial H-OilRC hy...

In relation to constant requirement for reduction of sulphur level and low demand for fuel oil, this study presents an approach for utilization of unconverted vacuum tower bottom (UVTB) from ebullated bed hydrocracking process – H-Oil technology in bitumen production. The conducted kinetic study shows slower softening point increase for crude blend...

The gasoline blending prediction models available in the open literature: Linear method, Ethyl method, Stewart method, Zahed method, and Twu method were tested on 25 gasoline blends prepared from 14 components used by LUKOIL Neftohim Burgas (LNB) refinery to produce commercial gasoline grades. The performed tests with these models showed prediction...

Start-up of the new H-Oil vacuum residue hydrocracker was accompanied by a lot of technical and process issues. Nevertheless only after an year of operation as a result of joint efforts of operator (LNB), technology supplier (Axens), and catalyst supplier (Criterion) the LNB H-Oil unit performance was significantly improved.The conversion and the y...

This work deals with reactivity of heavy oil SARA (saturates, aromatics, resins, asphaltenes) fractions during thermal and catalytic cracking, and the relations of heavy oil SARA composition to conversion level in both thermal and catalytic cracking. It was found that reactivity decreases in the order: saturates > aromatics > resins > asphaltenes....

The modern heavy oil conversion technologies are generally based on two processes: catalytic cracking and thermal cracking. They are the backbone of the modern refining business. Considering that the feedstock quality is the single variable that most affects the heavy oil conversion unit performance, and that the heavy oils are very complex mixture...

This paper summarizes the results of multiple experiments performed in the LUKOIL Neftohim Burgas Research laboratory related to the issue of high values of hot filtration test (HFT) of the residue H-Oil hydrocracking residual oil products. After the start-up of the new residue H-Oil hydrocracker in the LUKOIL Neftohim Burgas refinery during the se...

This project presents the procedure for determination of forty-five organic compounds in sour wastewater. The procedure is based on liquid-liquid extraction followed by gas chromatography. The analytical method with gas chromatography-mass spectrometry was used for identification of composition of the sour wastewaters with origin from ebullated bed...

Thirty-four heavy oils originating from the four main groups of crude oils around the world—I group: light, low sulfur (30–400 API; S ≤ 0.5% mass); II group: light sulfur (30–400 API; S = 0, 5–1.5% mass); III group: heavy, high sulfur (15–300 API; S = 1.5, 3.1% mass); IV group: extra heavy, high sulfur (150 API, S ≥ 3% mass)—were investigated for d...

A data base of 140 diesel fuels having cetane number in the range 10 ? 70 points and the physical properties: density at 15?C, and distillation characteristics according to ASTM D-86 T10%, T50%, and T90% was used to develop new procedures for prediction of diesel cetane number by application of the least squares method (LSM) using MAPLE software, a...

This work presents a study on feasibility to predict saturates plus mono-nuclear aromatic hydrocarbons content in vacuum gas oils from readily available physical properties and the empirical methods: n-d-M, API, Total, Conoco Phillips (COP), and that of Goosens. As a result of a wide literature search 44 vacuum gas oils (VGO) having saturate plus m...

Thirteen vacuum residual oils originating from Russia, Middle East, Asia, and South America were thermally cracked in a modified high-temperature–high-pressure batch autoclave reactor. It was found that the colloidal stability of the vacuum residual oils expressed by S-value was the dominant factor that affected the residue thermal reactivity. SARA...

The objective of present work is to develop appropriate kinetics and computational methods to measure briefly in laboratory test the storage terms of biodiesels and their blends with conventional diesel fuels. It is known that biodiesel fuels are characterised by biological and oxidative instability, which is determined by their chemical compositio...

Residue fluid catalytic cracking (RFCC) process can be used to process residual oils whose Conradson carbon is no higher than 6%. The single variable with the largest effect on RFCC unit performance is feed quality. An investigation showed that the yields of gasoline, light cycle oil (LCO), and coke correlated with the content of saturates, aromati...

Nalco's visbreaker optimisation program (Conversion Plus™II) was implemented on the visbreaker unit at Lukoil Neftohim Burgas refinery, Bulgaria. The treatment package was specifically designed by coupling unique laboratoryprocessability characteristics of visbreaker feed with actual unit operational observations. Laboratory processing of visbreake...

A database, containing some 76 diesel fractions (from laboratory and commercial units), was compiled at the LUK01L Neftohim Bourgas refinery to evaluate and select the most accurate correlation to predict the cetane number of diesel fractions. The database was used also for the development of two new correlations, which improve the accuracy of CN p...

Evaluation of opportunity to raise Euro V diesel production by increasing fluid catalytic cracking (FCC) light cycle oil (LCO) production was carried at the Lukoil Neftochim Bourgas, Bulgaria (LNB) refinery. The FCC LCO (IBP-360 °C) production was investigated in the FCC conversion range between 69 and 83 wt.% and LCO initial boiling point (IBP) be...

37 diesel fuels from different origins, with different aromatic contents and different molecular weights (boiling ranges) were in-vestigated with the aim of developing corre-lations between cetane index and amniotics content in diesel fuels. It was found that cetane number (CN) and cetane index (CI) correlate with total aromatic content of die-sel....

Cold flow properties and oxidation stability of near zero sulfur diesel from Ural crude oil and fatty methyl esters (FAME) from different origin and their blends were studied in this work. It was found that undercutting the petroleum diesel to obtain arctic diesel deteriorates its oxidation stability and anti-oxidant addition is required to keep th...

Four heavy diesel fractions (FBP according to ASTM D-2887 of about 420 °C), one lower boiling middle distillate fraction (FBP according to ASTM D-2887 of 310 °C) and kerosene fraction (FBP according to ASTM D-2887 of 271 °C) obtained from the Lukoil Neftochim Burgas (LNB) process units during the processing of Russian Export Crude Blend (REBCO) alo...

Changes in the fuel oil product specification (change of fash point specif cation from 110 C open cup to 60 °C in closed cup) led to a change in the operating mode of the main fractionator in the Visbreaking Process Unit of Lukoil Neftochim Burgas (LNHB). Following these changes a significant variation was observed in the visbreaking residue specif...

Cited By (since 1996):1, Export Date: 18 October 2014

The determination of fatty acid methyl esters (FAMEs) by gas chromatography is one of the most common analyses performed in biodiesel research. By using the potential of the capillary gas chromatography, the flame ionisation detector and the non-polar column was developed fast, efficient and reproducible method for determination of fatty acid methy...

Five different crude oils originating from Russia, Kazahstan, Azerbaidjan, and Iraq, were analyzed for their distillation characteristics in accordance with the methods: ASTM D-86, D-2892, and D-5236. Naphtha, kerosene, diesel and vacuum gas oil fractions obtained from these crude oils by their fractionation on a true boiling point (TBP) apparatus...

Naphtha streams from distillation of Ural crude oil, middle distillate hydrotreaters, vacuum gas oil hydrotreater and visbreaker have been characterised with the aim to evaluate the most appropriate way for their processing in the refinery. It was found that their octane ratings (RON) varied between 42 and 72. Their sulphur content varied between 3...

The influence of crude quality on refining profit was studied. Five samples of crude oil, which are representatives of the four basic types of crude available to refiners around the world (light-sweet, light-sour, heavy-sour crude, and extra-heavy), were considered, i.e., Brent Blend, Russian Export Blend, Kuwait Export, Maya. As profit from refini...

Fourteen type crude oils originated from USA, Mexico, Africa, Middle East, Russia, Canada,Colombia, Ecuador, and Venezuela having density and sulfur in the range API = 12.1 ÷ 40.8; S =0.4 ÷ 3.3% and total acid number varying in the range TAN = 0.1 ÷ 3.72 mg KOH/g oil havebeen investigated. The studied crude oils have been classified into four group...

The main obstacle in biodiesel/conventional diesel blends acceptance worldwide seems to be its poor oxidative stability. Low resistance towards oxygenation is due to the fatty constituent in the blend. Even low concentrations of biodiesel (5%, 10% and 20%) can contribute to sticky, viscous and polymeric deposits formation after several months of st...

Recently, a study was conducted to evaluate the predictability of four different correlations using various gas oils and blends with residual heavy oils obtained from the Lukoil Neftochim Bulgaria (LNB) vacuum distillation and visbreaking units. As a result, it found that one viscosity test at an arbitrary temperature and Singh's correlation can pr...

This work evaluates the influence of the Lukoil Neftochim Bulgaria FCC unit variables on FCC gasoline qualitywhile employing an octane-barrel catalyst. It was found that research octane number of the FCC gasoline directlycorrelated with the riser outlet temperature (ROT). FCC gasoline was found to consist of higher octane low boiling(that boil in t...

Benzene is toxic air pollutant and that’s why is set a constraint to 1% (v/v) in gasoline. Refiners have to lower benzene in its gasoline pool components. High benzene contributors are reformate and FCC gasoline. Worldwide practice is to optimize the reformate benzene content. Some light crude oils, like Samgori from Georgia contain more fraction w...

Catalytic cracking in fluidized bed is one of the most complicated and difficult processes in the sense of understanding. The reason for this is due to the fact, that change of one single parameter is related with changes of one or several parameters, which is consequence of utilities system balance. Statistic data processing from manufacturing FCC...

Cloud point (CP) and cold filter plugging point (CFPP) of 20 diesel range boiling fractions from different origin (both straight run and conversion effluents) were tested respectively by EN ISO 3015 and EN 116. Their values were calculated by using Khan's formula and CP was also calculated by means of a commercial process simulator. The accuracy of...