Crude Oil Content Research Articles

Effects of gradually increasing drying temperatures on energy aspects, fatty acids, chemical composition, and in vitro ruminal fermentation of acorn.

Acorns are commonly used to meet energy, protein, and mineral needs of livestock in various parts of the world. However, since acorns have quite a high moisture content at harvest, they should be stored as dried to prevent loss of nutrients and spoilage throughout storage periods. The aim of this study is to determine the drying kinetics, color, energy aspects, crude protein, crude ash, crude oil, fatty acid composition, ADF, NDF, condensed tannin, and mineral composition properties of acorns dried at gradually increasing drying temperatures. Drying processes were carried out in an air-convective dryer at temperatures of 40, 60, 80, 100, and 120 °C. The Logistic model was identified as the best model for describing current drying conditions. Increasing drying temperatures reduced L* (lightness) values and increased thermal efficiency and effective moisture diffusion values. In terms of energy efficiency, the best outcomes were achieved at 80 °C and 120 °C drying temperatures. Drying temperatures had highly significant effects on nutritional traits of acorn samples. Increasing drying temperatures increased fiber content, gas-methane production, and energy values and reduced crude protein and oil contents. Some minerals decreased and some others increased with increasing drying temperatures. Increasing drying temperatures caused slight changes in fatty acid compositions. In terms of animal drying and feeding characteristics, it was determined that a drying temperature of 80 °C was ideal for acorn drying.

Influence of bioaugmentation in crude oil contaminated soil by Pseudomonas species on the removal of total petroleum hydrocarbon

This study aimed to carry out the bioaugmentation of crude oil/motor oil contaminated soil. The mixture of novel strains Pseudomonas aeruginosa PP3 and Pseudomonas aeruginosa PP4 were used in this bioaugmentation studies. The four different bioaugmentation systems (BS 1–4) were carried out in this experiment labelled as BS 1 (Crude oil contaminated soil), BS 2 (BS 1 + bacterial consortia), BS 3 (Motor oil sludge contaminated soil), and BS 4 (BS 3 + bacterial consortia). The total petroleum hydrocarbon (TPH) was investigated for monitor the effectiveness of bioaugmentation process. The highest TPH removal rate was recorded on BS 4 (9091 mg Kg -1) was about 67% followed by 52% on BS 2 (8584 mg Kg -1) respectively. The percentage of biodegradation efficiency (BE) of residual crude and motor oil contaminated soil were evaluated by GCMS analysis and the results showed that 65% (BS 2) and 83% (BS 4) respectively. Further the bioaugmented soil was subjected to the plant cultivation (Lablab purpureus) and the results revealed that the L. purpureus was rapidly grown in the systems BS 4 and BS 2 than the system BS 1 and BS 2 which was due to the lesser biodegradation of the crude oil contents. In resultant, it can be concluded that the soil was suitable for the cultivation of plant. Overall, this study revealed that the selected bacterial consortia were effectively degraded the hydrocarbon and act as a potential bioremediator in the hydrocarbon polluted soil in a short period.

Occurrence characteristics and influential factors of movable oil in nano-pores by molecular dynamics simulation

CO2-enhanced oil recovery (CO2-EOR) technology has shown great application potential in the development of tight reservoirs. Since the proportion of nano-pores in tight oil reservoirs exceeds 77%, it is necessary to further study the occurrence state of crude oil in nano-pores. In this paper, the molecular dynamics simulation was applied to study the adsorption and diffusion behaviors of multi-component crude oil in quartz (hydrophilic) nano-pores. Besides, the density discretization method was used to investigate the occurrence characteristics of crude oil, the proportion of movable fluid in nano-pores, and the effects of CO2 and polar molecules (C3H6O) on the adsorption characteristics of crude oil. The simulation results showed that the adsorption state of crude oil in the quartz nano-pores was in the form of 4 adsorption layers with a thickness of 0.45 nm each. In nano-pores, the oil molecules with longer molecular chains were more likely to aggregate and adsorb on the quartz surface. Among them, polar oil molecules have the strongest adsorption capacity on the quartz surface. Moreover, the crude oil potential energy and the self-diffusion coefficient gradually increased from the vicinity of the quartz wall and tended to be stable in the free layer. Meanwhile, the content of movable crude oil gradually augmented with the increasement of nanometer pore width and temperature. Furthermore, the pressure had little effect on the density distribution of crude oil in the pores. In contrast, the temperature had a more significant effect on the density distribution of the adsorption layer. At last, due to the more substantial adsorption capacity of CO2 on the rock surface, the crude oil adsorbed initially on the rock surface would be stripped off by CO2, converting from irreducible oil to moveable oil.

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.

Using special additives for decreasing the asphaltene content of missan crude oil

In crude oil, asphaltene is one of the fractions that may be dissolved in aromatics like benzene or toluene but cannot be dissolved in alkanes like n-heptane, n-pentane, or petroleum ether (a mixture of alkane compounds). A typical difficulty in oil recovery and refinery processes is asphaltene precipitation, which happens when the oil stream's pressure, composition, or temperature change. So, the stability of asphaltene in crude oil needs to be looked at to find out how likely it is to form asphaltene so that it can be stopped and high treatment costs can be reduced. In the present study, saturate, aromatic, resin and asphaltene (SARA) analysis of Missan heavy crude oil from the (Omar River Field) was performed. Three additives were used to show their effect on asphaltene at different concentrations and temperatures. The additives included nanoparticles (nano ferric oxide red, nano silica oxide, and a mixture of nano silica and ferric oxide red) and the polymer fiberglass. The concentrations of the additives of the nanoparticles were (200 ppm, 3533 ppm, a867 ppm), (1667 ppm, 6667 ppm, 10000 ppm, and 16667 ppm) and (24000 ppm, 40000 ppm, and 48000 ppm) of nano-silica, ferric oxide red, and a mixture of nano silica and ferric oxide red, respectively, while fofiberglassss, 3733 ppm, 7066 ppm, 10400 ppm, and 13733 ppm) and measured at temperatures (5, 25, and 45oC) The best read I got was when it was used. 4.249% from origin to 6.375% after treating the percentage of asphaltene with 48000 ppm of ferric oxide red and nanoo-silica.

Application of multiple linear and polynomial regression in the sustainable biodegradation process of crude oil

Statistical regression models have been applied in various biotechnical applications to determine the relationship between response and conditional factors as well as to facilitate prediction. This research focuses on sustainable biodegradation process of crude oil using native and recombinant microbial strains to alleviate the significant environmental threat posed by crude oil contamination. This sustainable process is energy and cost-efficient compared to the traditional measures adopted in the extermination of the contaminated soil due to crude oil. The reaction of the wild and recombinant microbial strains to biodegradation rate was detected in the experimental study. These experimental data were used to develop multiple linear regression (MLR) and polynomial regression models (PR). The coefficient of determination, or R2 value, was used to validate the constructed models. The PR model had a high R2 of 0.863, whereas the MLR model had a low value of 0.495. The PR model provided the best match, and it also explains the impact of conditioning factors on the biodegradation rate. To summarize, the recombinant microbial strain yielded a better biodegradation rate with increasing incubation days at lower crude oil contents.

Synchronous pressing and refining after solid-phase preadsorption technology as a new method for rapeseed oil preparation

A new method for rapeseed oil preparation named synchronous pressing and refining after solid-phase preadsorption technology was investigated. Rapeseed and adsorbents were first mixed evenly to form premixes, and the product oils were then obtained by direct pressing and filtering. The phospholipid content, acid value, a* value, chlorophyll, carotene, polyphenol contents of crude oil increased, while L* and b* values decreased with increasing squeezing chamber temperature. A moderate adsorbent dosage and temperature could improve the refining effects. Silicon dioxide had the highest dephosphorization and deacidification rates of 95% and 42%, respectively, when the dosage was 30 g/kg at 130 °C. Activated clay decreased the chlorophyll and carotene contents by 75% and 38%, respectively. Sucrose fatty acid ester had dephosphorization and deacidification rates of 67s% and 41%, respectively. Ascorbic palmitate had a dephosphorization rate of 74% and retained polyphenols intactly. This technology would not affect the oil yield and could decrease the peroxide value of rapeseed oil. It realized the simultaneous completion of pressing and refining with the advantages of a short preparation time and environmental sustainability.

Desulphurization of crude oil using caustic soda: process modelling and optimization

The stringent environmental regulations on sulfur content of crude oil and refined products have necessitated the desulphurization of the natural resource. In this study, caustic desulphurization process using NaOH aqueous solution was applied to Nigerian crude oil sample containing 3.4995% sulfur content. The influence of process variables such as NaOH solution concentration, reaction temperature, and reaction time were modeled and optimized using central composite design of the response surface methodology. Based on the modeling results, the R2 and adjusted R2 values of 0.976 and 0.955, respectively, indicated that the model properly fitted the experimental data, implying the accuracy of the model prediction. The maximum predicted desulphurization rate of 58.3% was estimated under optimal conditions of 3 M NaOH solution concentration, 50 °C reaction temperature, and 30 minutes reaction time at a desirability of 1. The removal efficiency and economic feasibility of the process indicated that desulphurization of crude oil using NaOH aqueous solution should be recommended for use in the petroleum and petrochemical industries.

Development of free water knock-out tank by using internal heat exchanger for heavy crude oil

Reactivation of an old oil well can be explicitly calculated to maximize crude oil production. The biggest challenge with the activation process is the crude oil content in old wells, which is not feasible to meet the specified minimum standards. In the case of the Bunian oil field, Indonesia, the crude oil produced has high water content. It causes a decrease in the quality of production and also hinders production capacity. The production scheme applied to the Bunian field has a storage tank that functions to reduce water content using the gravity method, but this is less effective. Let’s modify the storage tank into a heat exchanger tank through the engineering design process and labeled it as a free water knockout tank (FWKO). The FWKO is made of a multi-pass tube heat exchanger. The experiments are conducted through three phases’ tests before deciding the final design. From the test, the change in water content is varied with temperature differences of the working fluid and crude oil. The lowest water content is obtained at 0.5 % at final tests. After analyzing the characteristic of each test result, the final design is taken by adjusting the suitable working fluid temperature and pressure. Finally, by using suitable parameters, the average water content of crude oil is decreased up to the minimum requirement (<0.1 %). The design of FWKO is considered simple with an excellent performance and can adapted easily. The FWKO able to process crude oil with water content <20 %, where it suitable for waxy oil well. The working fluid can be processed both in liquid and gas state. Furthermore, the heating source for the working fluid is gained from the gas flare by using thermic heater. Thus, it does not require an extra heating source for the heat exchanger

Biochemical composition of some <i>Melissa</i> L. and <i>Alcea</i> L. species introduced in Absheron

The article provides data on the study of the biochemical composition of the species Melissa officinalis, Alcea rugosa, A. kusariensis, A. hyrcana, A. rosea. Research were carried out in natural conditions and in Absheron, in cultural conditions on the experimental site of the Central Botanical Garden of the Azerbaijan National Academy of Sciences. The climate of Apsheron is mainly moderately hot and dry, subtropical and belongs to the semi-desert type. Gray-brown soils are widespread in the Central Botanical Garden. Of the studied species, two species, A. kusariensis and A. hyrcana, are rare species and listed in the “Red Book” of Azerbaijan. A. kusariensis is a rare endemic species of the Caucasus. A. hyrcana is a rare species in Azerbaijan. Determined primary moisture, hygroscopic moisture, the amount of dry matter, raw ash, raw fat and protein in the composition of the species. It was revealed that by the end of the growing season, the composition of the M. officinalis species decreases in crube ash, initial and hydroscopic moisture, while the amount of crude oil and protein increases. Compared to the underground part, the chemical composition of the aboveground part of the Alcea rugosa species is richer. Comparison of samples of this species growing in nature and in culture showed that the mass of raw ash and crude oil was higher in natural conditions, and the mass of protein was higher in cultured samples. Among the studied species, the prevalence of crude oil content was observed in A. hyrcana (4,35 %) and A. rosea (4,25 %) species, in A. kusariensis in terms of crude ash content (21,0 %), and in protein content in A. rugosa (22,5-28,19 %).

Application of near infrared spectroscopy in sub-surface monitoring of petroleum contaminants in laboratory-prepared soils

ABSTRACT This study was conducted to determine the suitability of near-infrared (NIR) spectroscopy for subsurface monitoring of crude oil contaminants in different soil types under different moisture conditions. Calibration tests, carried out in both wet and dry soils, with crude oil contents 5–30% indicate an inverse relationship between spectra and oil content with R2 values ≥0.98 for dry soil mixtures. A derived index termed “Oil Index” was generated by calculating a spectral ratio between the main oil peak in the NIR region and a spectrally inactive part of the spectrum within the visible region. It was used in a series of experiments designed to test whether NIR probes could yield useful information about the movement of oil through different soils. Synthetic crude oil was dropped into a series of soil samples of different particle size distribution and moisture content. Analyses of the 3D distribution of values of the Oil Index demonstrate that it is possible to estimate and map synthetic crude oil concentration in the subsurface of the soil samples. Results showed that while the Oil Index provided a reasonable estimation for oil concentration in dry samples, this was not the case for wet samples, although the Index was useful in understanding the pattern of movement of oil contaminant in wet soils. The work indicates that this technique may enhance field investigation of oil contamination, providing an accurate in-field technique.

Valorization of Carapa procera Oil and Evaluation in vitro of Antimalarial Activity of Its Bitter Content

Aims: To extract the bitter content of Carapa procera oil and to evaluate the antimalarial activity of its bitter content.
 Study Design: Experimental research.
 Place and Duration of Study: Department of Chemistry (University of Kinshasa) and National Institute for Biomedical Research, between December 2016 and June 2018.
 Methodology: The seeds of C. procera were collected in the Kwilu region (Democratic Republic of Congo). A standardized method of Soxhlet was used for the extraction and determination of the oil content. The bitter content of C. procera oil was removed by liquid-liquid extraction. Organoleptic sensory analyzes have used a test of the effectiveness of debittering.
 The in vitro antimalarial activity of bitter content, extracts, crude oil and the debittered oil on Plasmodium falciparum were evaluated according to the method of maturation test of trophozoites into schizonts.
 Results: Quality indexes such as acid values (12.72 and 2.72 mg KOH/g), saponification values (190.36 and 193.12 mg KOH/g), peroxide values (5.26 and 19.66 meq O2/Kg), and iodine values (69.09 and 68.63 g I2/100 g) was determined for crude oil and debittered oil respective antimalarial activity was evaluated. Crude oil and bitter content showed respectively significant antimalarial activity with IC50 values of 3.44 and 0.30 µg/mL.
 Conclusion: The elimination of the bitter content does not affect the quality of C. procera oil. These results were, for the most part, in accordance with the codex alimentarius for edible oils. Concerning the antimalarial activity, according to RITAM, C. procera crude oil could present probable antimalarial activity against P. falciparum (3.44 μg/mL), low value compared to that of the bitter content.

Analysis and Research on the Automatic Control Systems of Oil–Water Baffles in Horizontal Three-Phase Separators

The three-phase separator is one of the most important pieces of equipment in the combined station of the oilfield. The control level of the oil–water interface directly affects the energy consumption of the subsequent production of the combined station and the effect of oil, gas and water separation. In order to avoid these situations, the Siemens PLC control system, configuration software WinCC and MATLAB were used. The OPC technology is used to connect communication between WinCC and MATLAB, and the genetic algorithm in MATLAB is used to obtain the optimal separation height of the oil–water interface under the produced liquid in different periods. Subsequently, through the Siemens PLC system and WinCC configuration software, the automatic control of the three-phase separator is achieved, and finally the water content of crude oil is significantly reduced. The system provides a visual interface function. In the future, it will also provide an effective simulation platform for the theoretical research and design of an automatic control system of an oilfield combined station.

Chemical Composition, Antioxidant Capacity And Total Phenolic Content of Hazelnuts Grown In Different Countries

Hazelnut providing the macro-and micronutrients is a constituent of the healthy diet. Hazelnut, one of the most consumed treenut, is produced in the different countries. The geographical origin influences the chemical composition and the biological activity in the several plant foods. The purpose of this study is to evaluate the chemical composition, the antioxidative capacity and total phenolic content of the hazelnut kernels obtained from the different countries, including Azerbaijan, Chile, Italy, and Turkey. The hazelnut kernels were examined for crude oil, ash, moisture, and protein contents. The refractive index, iodine value, and fatty acid composition of the hazelnut oils were identified. In addition, the hazelnut oil, the kernels, and the defatted kernels were tested for their antioxidative activities and total phenolic contents. Protein contents of the hazelnuts from different countries were similar. The largest oil yield was determined in the hazelnut kernels from Chile and Turkey (62.35 ± 0.51 % and 62.29 ± 0.46 %, respectively). While the oil from Turkish hazelnut kernels showed the highest oleic acid content (84.09 ± 0.17 %), Azerbaijan hazelnut oil had the lowest oleic acid content (78.10 ± 0.48). The highest phenolic content was detected in the hazelnut kernels from Azerbaijan. Although the lowest phenolic content was observed in the hazelnut kernels from Turkey, the most potent antioxidative capacity was determined in the Turkish hazelnut kernels, their oil, and their defatted form. It can be concluded that the Turkish hazelnut kernels could contain high amounts of the fat-soluble antioxidants in addition to the water-soluble phenolic antioxidants. The results suggested that the hazelnuts exhibited different chemical composition, antioxidant capacity, and phenolic content depending on their origin.

Modeling the impact of reducing sulfur content of liquid fuels consumed by power plants on the air quality of Kuwait using AERMOD

As part of Kuwait’s plan to meet the country’s long-term sustainability goals, a new refinery is being constructed with an objective of desulfurizing crude oil (CO) and heavy fuel oil (HFO) to a low sulfur content, S% (approximately 1% by mass). Since Kuwait’s electric power system relies heavily on CO and HFO for electricity generation, the air quality impacts of this change in sulfur content should be investigated. In this work, three scenarios were examined and compared to the base case. The hourly SO2 emissions of each scenario were simulated using an air quality model (AERMOD) to determine the spatial and temporal SO2 dispersion for the year 2014. The three scenarios were developed based on lowering the sulfur content to 1% for HFO only, CO only, and both HFO and CO. The study results indicated that the annual SO2 emissions were reduced by 75.6%, 12.5% and 82.7% for the first, second and third scenarios, respectively, compared to the base case scenario. The daily averages of SO2 emissions of the first, second and third scenario were 57.7%, 12.4% and 70.1% lower, respectively, compared to the base case. The reductions in the maximum region wide one-hour average SO2 concentrations reached 47.4%, 24% and 54.1% for the first, second and third scenarios, respectively, compared to the base case. The numbers of hourly SO2 exceedances were reduced by about 94%, 54% and 100% for the first, second and third scenarios, respectively, compared to the base case (7361 hourly SO2 exceedances). The results of this analysis show the benefits of reducing the sulfur content of CO and HFO as mitigation strategy to reduce high ambient SO2 concentrations.

The influence of the viscosity of crude oil on liquid-dynamic noise characteristics in the volute shell of oil transfer pump

This paper aims to study the influence of the viscosity of crude oil on the liquid-dynamic noise characteristics using ANSYS Fluent. The RNG k-ɛ model is used for simulating the static pressure distribution characteristics of crude oil in the centrifugal pump. The LES S-L model is used for simulating the transient characteristics of crude oil in the centrifugal pump. The results show that the viscosity of crude oil is the primary factor affecting the static pressure distribution and the transient characteristics of crude oil in the centrifugal pump. The lower the viscosity of the crude oil is, the greater the change in static pressure is. The maximum static pressure peak appears nearby the tongue of oil transfer pump. The static pressure critical viscosity affecting the inner wall of the volute shell is 1728mPa.s. According to the viscosity test data provided by related literature, A 3-step mathematical characterization model is proposed to describe the relationship between the viscosity and the corresponding water content of crude oil. It can be used to compute the crude oil viscosity parameter as a given value in ANSYS Fluent program. The maximum relative deviation is 2.62%. A transmit method is proposed by heating up the pre-stable and post-stable crude oil twice to keep the viscosity constant in the whole progress of crude oil transmit. It will be beneficial to energy saving.

The effect of different medium-chain fatty acids, calcium butyrate, and salinomycin on performance, nutrient utilization and gastrointestinal tract of chicken of Polish Green-Legged Partridge hen

Abstract The present study aimed to determine the effect of diets supplemented by feed additives, on the growth performance and digestive tract functioning in chicken of Green-Legged Partridge hen (GLPH). Two types of diets were used. Both the “low-digestible” (LD) diet characterized by high level of crude fiber and lard, and the “high-digestible” (HD) diet characterized by low content of crude fiber and soybean oil were supplemented by different additives such as 0.34% DM (dry matter) salinomycin, 0.30% DM medium-chain triglycerides (MCT), 1.00% DM calcium butyrate (CB), or 0.85% DM medium-chain fatty acids (MCFA). The experiment was conducted on 960 one-day-old male chickens of GLPH, randomly divided into 10 treatment groups. One group consisted of 12 replications (each with 8 birds). Chickens fed HD diet presented significantly higher body weight gain (BWG) in 15–56 days and also 0–56 days of experiment and lower feed conversion ratio (FCR) during whole time (0–56 days) of experiment (P<0.05). Addition of CB and MCFA did not affect the differences in BWG (15–56; 0–56 days) and FCR (15–56 days) in comparison with the control diet. Significant interaction between the type of diet and additives (P<0.05) was observed for feed intake (FI) throughout the experiment. The highest FI was found on LD diet with CB. On LD diet, all additives resulted in significantly worse nitrogen retention, however, on HD diet, it was observed only for salinomycin. The additives had no impact on fat digestibility when chickens were fed HD diet. There was significant (P<0.05) lower-fat digestibility when LD diet with MCT, CB, and MCFA was used. The greatest value of nitrogen-corrected apparent metabolizable energy (AMEN) was found on HD diet (P<0.05). The addition of MCT, CB, and MCFA increased the percentage share of ileum, and MCT also significantly increased the percentage share of the liver. The lactic acid bacteria and C. perfringens counts were lower on HD diet (P<0.05). The addition of MCT and CB increased the count of lactic acid bacteria in caeca (P<0.05). Many interactions between experimental factors in this experiment showed that the efficacy of using different feed additives depends on the type of diet. The results suggest that MCFA may be the most beneficial feed additive for GLPH chicken as an alternative for antibiotic growth promoters (AGP).

Choline chloride-based deep eutectic solvents for ultrasonic-assisted oxidative desulfurization of actual heavy crude oil

Deep eutectic solvents (DESs) are acquiring increasing interest as ionic liquid analogues because of their wide application, low-cost characteristics and environmentally friendly. In this study, choline chloride-based (ChCl) as a type of DESs were synthesized using polyethylene glycol (PEG), and applied to reduce sulfur content of actual heavy crude oil with sulfur content 37900 ppm (3.79 wt%). The synthesized DESs were characterized using Fourier-transform infrared spectroscopy (FTIR), as well as viscosity and density measurements. The DESs were evaluated for extractive ultrasound-assisted oxidative desulfurization (EUAODS), with 30 wt% H2O2 as the oxidant and formic acid as the catalyst. This study looked at the effects of oxidative desulfurization (ODS) and single ODS under ultrasonic treatment. Different systems for DESs were tested to find the desulfurization selectivity of the better reaction system; and it was found that extractive desulfurization (EDS) removed 24.57% of the sulfur, followed by extractive and ultrasonic-assisted desulfurization (EUADS) at 26.78%, then ODS at 37.28%, with ultrasonic-assisted oxidative desulfurization (EUAODS) providing the best result of 62%. According to the comparison trials, combining DESs with ultrasonic treatment improved processing. This study contributes to the body of information on the use of ultrasonic treatment in heavy crude oil desulfurization.

Experimental study on wax removal and viscosity reduction of waxy crude oil by Ochrobactrumintermedium

To investigate the influence of microbial wax removal and viscosity reduction technologies on the fluidity of waxy crude oil, this study took the waxy crude oil from China's Daqing Oilfield as the experimental object for microbial wax removal and viscosity reduction experiment. First, utilizing standard strain screening and culture protocols, a high-efficiency microbial strain H-1 (Ochrobactrum intermedium) was proposed from in situ soil. The single factor experiment and multi-factor response surface analysis were then utilized to optimize the temperature, initial pH value of the medium, and NaCl mass concentration needed for the strain's growth. Oil displaced activity and emulsification tests were used to evaluate the biosurfactants produced by the metabolism of strain H-1, and Fourier transform infrared spectroscopy was used to identify the types of biosurfactants. Finally, the application effect of strain H-1 on wax removal and viscosity reduction of waxy crude oil were clarified through the wax crystal morphology, wax content, and viscosity of waxy crude oil. The research findings indicated that strain H-1 produced best at a temperature of 38.5 °C, pH value was 7.1 and the mass fraction of NaCl was 0.64%. The lipopeptide biosurfactant produced by strain H-1 can displace oil. Additionally, strain H-1 has a high emulsifying capacity, with a 61.25% emulsifying coefficient. After 7 days of treatment with the strain H-1, the wax crystal morphology of the waxy crude oil changed from a large-sized aggregated to a small-sized sparse condition, and the wax content of the waxy crude oil fell by 38.67%. The viscosity reduction rate of strain H-1 to waxy crude oil was consistently greater than 30% over the temperature range of 30–42 °C, with the greatest rate of 42.38% at 39 °C. The preceding results demonstrate that strain H-1 can degrade the wax components of waxy crude oil, lower the crude oil's low temperature viscosity, and then improve the crude oil's low-temperature fluidity.

Experimental analyzing the effect of n-heptane concentration and angular frequency on the viscoelastic behavior of crude oil containing asphaltene

Asphaltene often produces problems in upstream and downstream sections of crude oil transportation and processing equipment. These issues are directly related to the asphaltene precipitation in transportation pipelines, separation columns, heat exchangers, and storage tanks. This research investigates the impact of angular frequency and n-heptane concentration on asphaltene precipitation and rheological behavior of two oil samples from the Mansouri oil field in Iran, i.e., 23 and 71. The viscosity tests revealed that these oil samples and their mixtures with n-heptane exhibit Newtonian behavior. Moreover, increasing the n-heptane concentration increases the asphaltene precipitation and dramatically decreases crude oil viscosity. The frequency tests revealed that the presence of n-heptane has an unfavorable effect on crude oil’s viscoelastic behavior. Therefore, it is necessary to find the optimum range of angular frequency and n-heptane concentration to minimize the asphaltene content of crude oil and provide them with appropriate viscoelastic behavior. Increasing the angular frequency continuously increases all oil samples’ loss modulus and strengthens their liquid-like manner. The experimental results confirmed that the angular frequency higher than 33.6 rad/s and 75% volume concentration of n-heptane is the best condition for the oil sample of 23. On the other hand, the angular frequency higher than 23.4 rad/s and 75% volume concentration of n-heptane is the best condition for the oil sample of 71. In these conditions, the oil samples of 23 and 71 not only have appropriate viscoelastic behavior, but they also experience 97.2% and 96.3% reductions in their viscosity, respectively.