Sour Crude Oil Research Articles

Efficient hybrid strategy for simultaneous design of refinery hydrogen networks and pressure swing adsorption unit

Refineries face increasing hydrogen demand due to the consumption of heavy and sour crude oil. This study presents a novel hybrid method to optimize hydrogen network configurations with a rigorous pressure swing adsorption (PSA) process model. This method utilizes Bayesian optimization to address the upper-level unknown constraints black-box optimization problem while employing deterministic algorithms to manage the lower-level nonlinear programming problem. Furthermore, infeasible regions are transformed into feasible ones by introducing a dummy stream, and the costs incurred during the transformation process are accurately calculated. The proposed method is validated using two literature cases. In Case 1, Bayesian optimization outperformed the Kriging model, resulting in a 7.84% reduction in total annual cost (TAC). In Case 2, a comparison of four search strategies revealed the developed two-phase strategy as the most effective one. This method offers a powerful and practical tool for optimizing real-world hydrogen networks with PSA processes.

Streamlining the biodesulfurization process: development of an integrated continuous system prototype using Gordonia alkanivorans strain 1B.

Biodesulfurization is a biotechnological process that uses microorganisms as biocatalysts to actively remove sulfur from fuels. It has the potential to be cleaner and more efficient than the current industrial process, however several bottlenecks have prevented its implementation. Additionally, most works propose models based on direct cultivation on fuel, or batch production of biocatalysts followed by a processing step before application to batch biodesulfurization, which are difficult to replicate at a larger scale. Thus, there is a need for a model that can be adapted to a refining process, where fuel is being continuously produced to meet consumer needs. The main goal of this work was to develop the first bench-scale continuous biodesulfurization system that integrates biocatalyst production, biodesulfurization and fuel separation, into a single continuous process, taking advantage of the method for the continuous production of the biodesulfurization biocatalysts previously established. This system eliminates the need to process the biocatalysts and facilitates fuel separation, while mitigating some of the process bottlenecks. First, using the bacterium Gordonia alkanivorans strain 1B, continuous culture conditions were optimized to double biocatalyst production, and the produced biocatalysts were applied in batch biphasic biodesulfurization assays for a better understanding of the influence of different factors. Then, the novel integrated system was developed and evaluated using a model fuel (n-heptane + dibenzothiophene) in continuous biodesulfurization assays. With this system strain 1B surpassed its highest biodesulfurization rate, reaching 21 μmol h-1 g-1. Furthermore, by testing a recalcitrant model fuel, composed of n-heptane with dibenzothiophene and three alkylated derivatives (with 109 ppm of sulfur), 72% biodesulfurization was achieved by repeatedly passing the same fuel through the system, maintaining a constant response throughout sequential biodesulfurization cycles. Lastly, the system was also tested with real fuels (used tire/plastic pyrolysis oil; sweet and sour crude oils), revealing increased desulfurization activity. These results highlight the potential of the continuous biodesulfurization system to accelerate the transition from bench to commercial scale, contributing to the development of biodesulfurization biorefineries, centered on the valorization of sulfur-rich residues/biomasses for energy production.

Decision Analysis to Avoid Unplanned Shutdown and Catastrophic Failure Due to Sour Crude Oil Processing in Crude Distillation Unit (CDU)

The Crude Distillation Unit (CDU) plays a pivotal role as the primary production unit in crude oil processing. Changes in the operational patterns of crude oil processing have unveiled potential issues that demand the refinery's capability to process Sour Crude. This type of crude oil contains relatively high impurity levels, with a Total Acid Number (TAN) of 0.3 Mg KOH/g and a sulfur content of 1.5 wt%. This has the potential to impact the remaining life and damage modes of equipment and pipes in the Preheater System due to an increase in corrosion rates. This study aims to identify the root causes and propose alternative solutions to address the possibility of damage, particularly leaks, in the Preheater system of the CDU. The focus is on preventing unplanned shutdowns and reducing the risk of catastrophic issues that may arise from the damage to the CDU's preheater system. These steps are crucial to ensuring the continuity of feed supply for secondary processes and valuable product stocks, essential for the operations of Refinery unit. The research employs Fault Tree Analysis (FTA) and Analytic Hierarchy Process (AHP) methods to evaluate several alternative solutions. The analysis results are expected to provide guidance in selecting the most effective and efficient solution, minimizing the risk of preheater system damage, and maintaining the optimal performance of the CDU.

The Effect of Nickel, Vanadium, Asphaltene, NSO and Sulfur on Crude Oil Quality

The Mishrif reservoir (Cenomanian - Turonian) in the Z, H, B and N oilfields in southern Iraq was investigated to clarify how nickel, vanadium, asphaltene, NSO and sulfur content affect the crude oil quality. The GC-Mass and ICP-MS analyses were used to provide fruitful hydrocarbon results. Classification of crude oil based on API gravity broadly indicates the oil's density and general properties. Typically, lighter crude oils are easier to refine, yield higher percentages of valuable products such as gasoline and diesel, and have a higher market value. Heavier crude oils require more processing and may yield more residual products, such as heavy fuel oil and asphalt. The Mishrif crude oil was classified as a medium sour crude oil containing high sulfur content (%) in Z oilfield (5.22), H oilfield (5.1), and B (5.12); more significant than those in N crude oil, which is classified a sweet based on less than 5% sulfur. The content of asphaltene, nickel, NSO, and vanadium affects the quality of crude oil and the market price because of its negative impact on refining processes, susceptibility to corrosion, and environmental damage later after fuel consumption and burning.

Microporous activated carbon catalyst for an efficient and deactivation resistive supercritical water upgrading process of sour crude oil

Microporous activated carbon catalyst for an efficient and deactivation resistive supercritical water upgrading process of sour crude oil

Technology solutions and challenges for marginal development of heavy oil fields in CuuLong basin, offshore Vietnam

The production of heavy oil at Dong Do field located in CuuLong basin is a success in the application of advanced technologies. Dong Do field is a marginal project in Vietnam, so its development requires to overcome several challenges, such as high water-cut from early stage, highly unconsolidated sandstone reservoir, flow assurance problems of sour and viscous crude oil, high power artificial lift system, and complex crude treatment at topsides, among others. Over the past decades, production technology application in heavy oil production has been widely deployed in the industry. Apart from the thermal method, the combination of gaslift and ESP technology makes the remarkable advances by enlarging the draw-down created over the conventional pumping lift in heavy oil projects. In fact, heavy oil production with a high flow rate has appeared water-coning in near wellbore region that made the water breakthrough early and water-cut increased rapidly. The pilot test of injecting diesel into heavy oil wells has been applied to producers with the positive results while significantly reduced water-cut comparing before wells shutin. This paper provides a thorough analysis of the new technologies that are applied to Dong Do field, highlighting its key difficulties and how they were resolved through a successful pilot and testing of the cutting-edge advanced solutions, improving the project reliability and thus motivating the consortium to move on to the new field. Also, the updated new heavy oil field schedule is described, highlighting the challenges to be faced during the next projects of marginal development.

Classification and determination of sulfur content in crude oil samples by infrared spectrometry

Determining and classifying the sulfur content of crude oil has long been of great importance because of its adverse economic and environmental effects. In this study, the total sulfur concentration in crude oil samples was determined and classified using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and chemometric methods. The methods designed for the analysis of crude oils are rapid, economical and non-destructive in the production process of the petroleum industry. Two sets of 70 and 31 samples in regression models were considered for the calibration and prediction sets, respectively. The calibration models were developed using the partial least squares regression model (PLS-R) and support vector machine regression model (SVM-R). Different pre-processing methods were also evaluated for the development of models. The preprocessing methods based on baseline correction, standard normal variate (SNV) and the auto scale were selected for regression and classification models. The use of SVM-R as a non-linear regression provided a model with significantly better root mean square error of prediction (RMSEP) values than the PLS-R model as a linear model. The ATR-FTIR spectral data were also applied by supervised classification method using the partial least squares-discriminant analysis (PLS-DA) and support vector machine-discriminant analysis (SVM-DA) for classifying crude oils based on sulfur content. The samples were classified into two classes according to the sulfur content into sweet and sour crude oil. The result of the classification found an accuracy of 96% and a classification error of 0.0384 for the prediction set in the PLS-DA algorithm. The results indicated that ATR-FTIR spectroscopy associated with multivariate calibration and classification models is a rapid and reliable approach for parallel quantification and qualification of the sulfur content present in crude oils.

Synthesis of refinery desulfurization solvent network with multi-stage solvent regeneration

Increasing process of sour crude oil and demand of low-sulfur oil products expand the desulfurization units in refineries, which raises the desulfurization solvent circulation as well as the energy cost for solvent regeneration. In this work, synthesis of desulfurization solvent network with multi-stage solvent regeneration is investigated to reduce the energy cost. Firstly, this work presents superstructures for desulfurization solvent network with regeneration considering one-stage structure, two-stage cascaded structure, and two-stage parallel structure, respectively. Next, mathematical models for the three cases are formulated as nonlinear programming problems where the objective function aims to minimize the total energy consumption. Finally, a case study is conducted to illustrate the proposed method. The results show that the two-stage structures reduce more energy costs than the one-stage structure by 7.65% and 8.46%, respectively, which means that two-stage regeneration is more attractive. Besides, the parallel structure is better than the cascaded structure, because the energy requirement for solvent regeneration is more sensitive to the outlet concentration of hydrogen sulfide than the inlet concentration.

Neural network supported flow characteristics analysis of heavy sour crude oil emulsified by ecofriendly bio-surfactant utilized as a replacement of sweet crude oil

The present study was carried out to assess the replacement of the sweet crude oil (SWCO) with the natural additive surfactant (NAS) namely Madhuca latifolia for the emulsification of heavy sour crude oil (SOCO) in order to facilitate eco-friendly transportation. In this study, the flow characteristics of SOCO were investigated with and without emulsification with SWCO and NAS. Both additives were blended in 10 to 15 percent (by volume) in heavy sour crude oil. The rheological properties of the SOCO suspension were measured by a rheometer ranging from 0 to 500 s−1 for shear rate ranges. The temperature scale was taken as 32±9 °C throughout the investigation. The rheological properties of sour crude oil including steady-state behavior, yield stress, viscosity, thixotropic properties, and other non-uniform steady characteristics were studied during the experimentation. Dynamic light scattering and optical microscopy were employed to investigate the morphology and the distribution of the wax in the SOCO and its emulsions. The flowability of SOCO and its emulsions was evaluated by Fourier transform infrared spectroscopy i.e. FTIR. The flow properties of SOCO were found non-Newtonian at low temperatures and its viscosity was decreased with an increase in temperature. Rheological results demonstrate that the addition of Madhuca latifolia and SWCO caused a reduction in the viscosity of SOCO. However, the viscosity of SOCO was decreased more by the emulsification with Madhuca latifolia as compared to SWCO. However, the CC, CH, and CO bonds are disintegrated in the presence of the Madhuca latifolia functional group.

Desulfurization of sour crude oil using an invasive weed adsorbent: An efficient, eco-friendly, and ultra-low-cost option

Desulfurization is a technology commonly used by refineries to mitigate the environmental burden caused by toxic gas emissions from hydrocarbon fuels. Expanding global population will increase liquid fuel demand by 20% between 2018 and 2050, with a total consumption of 240 quadrillion British thermal units (Btu) in 2050. Conventional catalytic Hydrodesulfurization (HDS) accounts for high cost and severe operating conditions (high temperature, pressure, catalyst poisoning and H2S safety). While studies have shown that adsorptive desulfurization (ADS) is highly effective in the removal of organic sulfur, limitations in the regeneration of adsorbent and selection of adsorbent with suitable structure to remove organic sulfur compounds exist. On the other hand, Prosopis juliflora, the world's most threatening invasive weed causes multifaceted environmental problems. The present study offers a novel solution that addresses both these issues contributing to climate change. Desulfurization of sour crude oil sample is performed using chemical-free, non-activated charcoal obtained from invasive weed species as adsorbent. XRD analysis showed amorphous structure and FTIR analysis confirmed the presence of CC bending functional group of the adsorbent. Adsorption-desorption isotherm showed presence of mesopores with pore diameter of 2.718 ​nm. Kinetic study findings reported 46% removal of total sulfur. GCMS findings showed efficient removal of some organic sulfur, including 100% removal of dibenzothiophene 4-methyl -. The equilibrium data is best represented by Freundlich isotherm. ICP-OES tests indicate the removal of toxic elements as well. The cost of the adsorbent is USD 0.12628 per kg, the lowest among all the adsorbents known thus far. The present study describes a novel, ultra-low cost, efficient, eco-friendly, desulfurization process that implements a chemical-free, non-activated adsorbent, achieves synergy, and offers multi-dimensional benefits to the environmental development. To our knowledge, this is the first study to characterize desulfurization of sour crude oil using an invasive weed.

Conceptual approach for simultaneous targeting and design of refinery desulfurization solvent network

With the increasing supply of sour crude oil and rising demand of low-sulfur fuel oil products, desulfurization becomes important in refineries, leading to notable energy cost for desulfurization solvent regeneration. This paper presents the integration of desulfurization solvent network and develops a systematic targeting and design method in order to improve the overall solvent utilization. First, the desulfurization solvent sink/source and desulfurization solvent network are defined referring to the characteristics of desulfurization units. Next, a novel problem table method is developed to identify the minimum fresh solvent consumption and design the desulfurization solvent network simultaneously. A case study is conducted to provide quantitative insights in designing desulfurization solvent network and saving fresh desulfurization solvent. Such integration reduces the fresh solvent consumption by 25% and has a good practicability.

Mathematical modeling and experimental study of sulfur removal process from light and heavy crude oil in a bed occupied by ferric oxide nanocatalysts

The elimination of hydrogen sulfide from the crude oil considered as an important process in the oil refineries which reduces sulfur concentration of crude oil Application of nanocatalysts in the elimination of sulfur from oil considered as a modern method. In this research, the ferric oxide nanocatalyst with diameter of 54 to 91 nanometers has been used in the refinement of sour crude oil. In this work, the theoretical equations have been driven in order to investigate the sour oil desalination process in a nanocatalytic bed, mathematically. Several experiments have been designed to evaluate the process of hydrogen sulfide separation from sour crude oil. Two different types of crude oil have been used in this research. The API of heavy crude oil is 18.6 and the API of light sample is 33.4. The effects of various operational parameters such as operating conditions, geometric parameters have been studied in this study. In addition, the effect of nanocatalyst size variation on the sweetening process is evaluated. Based on the obtained results, temperature of 55 °C and pressure of 1.6 bar have been introduced as optimal temperature and pressure, respectively. Also, the experimental data show that the maximum amount of sulfur compounds is separated from sour oil when the diameter of the catalytic bed is 2.5 cm. • In this study, two samples of light and heavy oil have been sweetened. • Ferric oxide nano catalyst was used for sweetening. • Operating and geometric conditions of laboratory tower have been studied. • Results show that temperature of 55 °C and pressure of 1.6 bar are the best operating condition.

Safety Considerations by Synergy of HAZOP/DMRA with Safety Color Maps—Applications on: A Crude-Oil Processing Industry/a Gas Transportation System

A collaborative framework by the synergy of Hazard and Operability (HAZOP) process and the Decision-Matrix Risk Assessment (DMRA) in association with safety-color mapping (SCM) is presented, in order to identify critical points and prioritize risks, and also to visualize the occupational safety and health (OSH) situation, at the workplaces (i) of a sour crude-oil processing industry (SCOPI), and (ii) of a measurement and regulatory station (MRS) in a gas transportation system (GTS), situated in Greece. Firstly, the conventional HAZOP analysis is executed in order to identify the potential fault causes of abnormal conditions (deviations) in the plants. The application of the DMRA-modus is valuable to rank the identified risks (hierarchy of risks). In view of the results, both of the HAZOP pattern (for identifying the hazards) and also the DMRA one (for assessing and ranking the risks), SCMs have been derived for the specific workplaces of the SCOPI and the MRS/GTS station, which could be a precious means for safety managers to appraise the urgency of investing limited budgets in measures preventing particular types of deviations, and also protecting the employees.

Multivariate Calibration of Sulfur in Sour Crude Oils via Near-Infrared Spectra

Regular supplies of crude oils during a nominal two-year period were used to develop and test partial least squares (PLS) multivariate models for determining sulfur based on near-infrared (NIR) spectra. Several models built automatically by chemometrics software were selected for testing in a series of cross validations and via large, independent prediction data sets. Three “annual” multivariate models were created in this manner, comprising the spectra acquired in 2017, 2018, and 2019, with each of them tested with the remaining two sets used for independent predictions. One of those three models performed best in terms of combined calibration and prediction errors, with the other two being suboptimal either because of the higher calibration errors or because of the limited predictive abilities. This is followed by creating three biannual models with the respective remaining set used for the prediction. Updating the models in this manner largely proved beneficial primarily due to alleviating the issues seen in the suboptimal models. The overall prediction error based on the analysis of about 1300 industrially relevant samples and across two years of acquisitions steadily indicates the prediction error of about 0.1 wt % for crude oils with the average content of ∼3 wt % of sulfur.

Nitrogen Protection as Anticorrosion and Fireproofing Measure in the Use of Sour Crude Oil Storage Tanks

The results of using a nitrogen protection system for 15 years in a sour crude oil storage park equipped with Hazmat class II and III vertical storage tanks with a stationary roof without pontoons are analyzed. Under nitrogen protection conditions, the rate of localized corrosion of the inner surface of the roof of raw and commercial crude oil storage tanks is 0.013–0.015 mm/year, which is ∼100 times lower than the rate of corrosion under natural gas phase conditions inside the tank. Continuous operation of the nitrogen protection system ensures fire and explosion safety of the tanks. Interruptions in the nitrogen protection do not have any practical effect on the efficiency of through perforation of the roof until the end of the regulated service life of the tanks, but increase fire and explosion hazard due to the formation of pyrophoric corrosion deposits.

Upgrading Siberian (Russia) crude oil by hydrodesulfurization: Kinetic parameter estimation in a trickle-bed reactor

Abstract Hydrodesulfurization (HDS) of sour crude oil is an effective way to address the corrosion problems in refineries and is an economic way to process sour crude oil in an existing refinery built for sweet oil. Siberian crude oil transported through the Russia-China pipeline could be greatly sweetened and could be refined directly in local refinery designed for Daqing crude oil after the effective HDS treatment. In this study, the HDS of Siberian crude oil was carried out in a continuous flow isothermal trickle-bed reactor over Ni-Mo/γ-Al2O3. The effects of temperature, pressure and LHSV were investigated in the ranges of 320–360 °C, 3–5 MPa and 0.5–2 h−1, keeping constant hydrogen to oil ratio at 600 L ∙ L−1. The HDS conversion could be up to 92.89% at the temperature of 360 °C, pressure of 5 MPa, and LHSV of 0.5 h−1, which is sufficient for local refineries (> 84%). A three phase heterogeneous model was established to analyze the performance of the trickle-bed reactor based on the two-film theory using Langmuir-Hinshelwood mechanism. The order of sulfur component is estimated as 1.28 and the order of hydrogen is 0.39. By simulating the reactor using the established model, the concentration of H2, H2S and sulfur along the catalyst bed are discussed. The model is significantly useful for industrial application with respect to reactor analysis, optimization and reactor design, and can provide further insight of the HDS of Siberian crude oil.

Is the leadership of the Brent-WTI threatened by China’s new crude oil futures market?

The recent listing of a new crude oil futures contract on the Shanghai International Energy Exchange (INE) has reopened the debate over whether crude oil produced in different countries or locations constitutes a unified world oil market. The aim of this paper is to study the information flows among Brent, West Texas Intermediate (WTI) and the new Medium Sour Crude Oil (SC) futures contract listed on INE futures markets to assess whether the trading of this new futures contract has altered the dominant role of the most traded oil benchmarks in the world. A multiple regression model identifies the Brent futures market as the most influential market in the oil price discovery process, while WTI appears to be the most sensitive. Furthermore, we have observed that SC does not influence any market and it is only sensitive to Brent news, even though WTI is the most heavily traded futures contract. Therefore, the launch of the SC futures contract has not yet altered the dominant role of Brent over WTI.

Upgrading Siberian (Russia) crude oil by hydrodesulfurization in a slurry reactor: A kinetic study

Hydrodesulfurization (HDS) of sour crude oil is an effective way to address the corrosion problems in refineries, and is an economic way to process sour crude oil in an existing refinery built for sweet oil. In the current study, the HDS of Siberian crude oil was carried out in a slurry reactor. The Co–Mo, Ni–Mo, and Ni–W catalysts supported on γ-Al 2 O 3 were compared at the temperature of 340 °C and the pressure of 4.5 MPa. The HDS activity follows the order of Co–Mo > Ni–Mo > Ni–W at a high concentration of H 2 S, and the difference between Co–Mo and Ni–Mo becomes insignificant at a low concentration of H 2 S. The influence of reaction temperature 320–360 °C and reaction pressure 3–5.5 MPa was investigated, and both play a positive role in the HDS reaction. A kinetic model over Ni–Mo/Al 2 O 3 in the slurry reactor was established. The activation energy is estimated as 60.34 kJ·mol −1 ; the orders of sulfur components and hydrogen partial pressure are 1.43 and 1.30, respectively. The kinetic parameters are compared with those in a trickle-bed reactor, implying that the mass transfer is greatly enhanced in the slurry reactor. The back mixing effect is present in the slurry reactor and can be reduced by a multi-stage design, which would lead to higher reactor efficiency in industrial application. • Sweetening Siberian crude oil (HDS) meets the requirement of local refinery in Daqing. • A kinetic model over Ni–Mo/Al 2 O 3 in the slurry reactor is established. • The orders of sulfur component and hydrogen are 1.43 and 1.30, respectively. • The activation energy is 60.34 kJ ∙ mol −1 . • Mass and heat transfers are enhanced in the slurry reactor.

Extraction Separation of Sulfur Compounds From Crude Oils in a Flow-Through Mode

A flow-through method is proposed for the separation of sulfur compounds from sulfur and sour crude oils by solvent extraction using centrifugal extractors. The effectiveness of using various organic (tetrahydrofuran, pyridine, methanol, ethanol, acetone, dimethylformamide, and acetonitrile) and inorganic (mineral acids, NaOH) extractants for the extraction of sulfur-containing compounds from crude oils of the Ashal’chinskii and Romashkinskii deposits is estimated. It is shown that methanol and dimethylformamide are most effective for extracting sulfur from crude oils. The use of additional sample preparation, which consists in the ultrasonic and/or magnetic processing of oil in combination with its oxidation and heating, increases the efficiency of extraction of sulfur-containing compounds by 20–40%. It is shown that the choice of extractant composition for the extraction of sulfur compounds is determined by the physicochemical properties and composition of the oil.

An expanded HAZOP-study with fuzzy-AHP (XPA-HAZOP technique): Application in a sour crude-oil processing plant

An integrated Hazard and Operability (HAZOP) study with the Decision Risk-Matrix (DRMA) and the Fuzzy-Analytical Hierarchy-Process (FAHP) is suggested as an alternative approach to identify and prioritize potential hazards in a sour crude-oil processing plant, located in the prefecture of Eastern Macedonia region in Greece. Therefore, the aim of our work is the development and application of the expanded FAHP-HAZOP-DRMA approach (XPA-HAZOP) in this industry. Firstly, the conventional HAZOP-analysis is applied for identifying the potential fault causes of abnormal circumstances in the plant. With the combination of HAZOP with DRMA for assessing the risks, the Fuzzy-AHP process is then introduced in order to broaden HAZOP-study and prioritize the hazards of the plant. The proposed XPA-HAZOP technique could be a functional tool for the decision makers about: (i) the ranking of hazards, compared to conventional HAZOP, and (ii) the emergency of investing restricted budget in actions preventing particular type of deviations.