Bharat Petroleum (India)

This study examines the corrosion behavior of natural gas pipelines through electrolyte-based simulations and computational fluid dynamics (CFD) modeling of gas–liquid multiphase flow, focusing on the synergistic effects of hydrogen sulfide (H₂S) and carbon dioxide (CO₂) in aqueous environments. Corrosion initiates at a water concentration of 1250 mg L⁻¹ under 40 kg cm⁻² pressure, decreasing to 1000 mg L⁻¹ as pressure increases to 200 kg cm⁻². Elevated pressure enhances electrochemical activity, gas solubility, and acidity, thereby intensifying corrosion. At lower H₂S levels, the formation of a protective iron sulfide (FeS) layer stabilizes the pH and reduces corrosion rates, whereas temperatures exceeding 30 °C compromise the protective integrity of both FeS and iron carbonate (FeCO₃) films. CFD results reveal that corrosion severity is influenced by hydrodynamic conditions, particularly in regions with thin water films and high shear stress. In horizontal pipelines, the 60° elbow exhibits the thickest water film (55 µm) and highest shear stress (~13 Pa), followed by the 90° (54 µm, ~13 Pa) and 30° elbows (52.2 µm, 9.57–11.0 Pa), whereas straight sections maintain significantly thinner films (0.11–1.10 µm). In the vertical plane, the 45° elbow demonstrates the greatest corrosion susceptibility, with the thickest water film (68.6 µm) and shear stress (~15 Pa). Overall, elevated pressure, temperature, and flow turbulence promote localized corrosion by enhancing gas dissolution and disrupting protective surface films.

Human arterial blood pressure follows a circadian rhythm, where pressure is highest during the day and lowest during the night. Patients with hypertension can have either a preserved rhythm or a dampened rhythm with a lower day-to-night difference, called "dippers" and "nondippers," respectively. Spironolactone, eplerenone, and the newer finerenone are mineralocorticoid receptor antagonists (MRAs) used for patients with resistant hypertension. In this study, we describe the 24h diurnal cycle in blood pressure in mice with and without hypertension to test whether high blood pressure induced a nondipping phenotype. Moreover, we tested whether the 3 MRAs affected the 24h cycles in blood pressure in the mice. Radiotelemetry devices were used to monitor blood pressure continuously in freely roaming mice (n = 19). Hypertension was induced by l -nitroarginine methyl ester ( l -NAME, 1 g/L) dissolved in the drinking water. A dipping phenotype was acknowledged if the nocturnal reduction in blood pressure was >10%. The 3 MRAs were administered orally once daily. Significant 24h rhythms were identified in blood pressure and 89% of the mice had a dipping phenotype at baseline. Only 42% of the hypertensive mice were dippers ( P > 0.05 vs. baseline). The MRAs at the doses tested did not change the 24h rhythm in blood pressure, and they did not restore a dipping phenotype in the nondipping hypertensive mice. Thus, l -NAME causes hypertension in mice and induces a "nondipper" phenotype in most of the mice. Spironolactone, eplerenone, or finerenone at the selected doses do not change arterial blood pressure in hypertensive mice.

This study presents a sustainable process for the production of L-lactic acid from rice straw, an abundant agricultural residue. Rice straw was subjected to dilute acid pretreatment, followed by enzymatic hydrolysis to convert cellulose into glucose, which was subsequently fermented to produce lactic acid. An integrated process for in situ lactic acid removal during high cell density fermentation using nonsterile resin was studied. A systematic approach was adopted to study the adsorption characteristics of the resin and the impact of impurities present in the fermentation broth on the resin performance to improve the yield and purity of the lactic acid in downstream processing. An overall process yield of 77% and purity of 89% were achieved, representing a 39% improvement over conventional pH strategies, with 94% reduction in salt generation compared to conventional precipitation methods and productivity of 1.19 g/(L h), superior to recent literature values of 0.329–0.430 g/(L h).

This study presents a comprehensive evaluation of VG30 bitumen modified with char derived from the co-pyrolysis of groundnut shells (GS) and plastic wastes, including high-density polyethylene, low-density polyethylene, and polypropylene. Char-modified bitumen samples were prepared with incremental char dosages ranging 3% to 15% by weight, and systematically assessed for their physical, mechanical, and chemical properties in accordance with relevant Indian Standards. The results revealed a consistent decline in specific gravity across all series—from 0.980 to 0. 0.9640. Penetration values decreased from 46 to 31 (0.1 mm), signifying enhanced stiffness, while ductility reduced from 104 cm to 35 cm for HDPE induced biochar. Softening point improved significantly, reaching up to 67.25 °C for GS + HDPE-modified binders at 15%, approaching VG40 (50 °C) performance. Absolute viscosity at 60 °C increased from 3087.86 Poise (control) to 6147.15 Poise, while kinematic viscosity at 135 °C rose from 380 cSt to 706.02 cSt, confirming superior high-temperature resistance and deformation stability. FTIR spectroscopy identified notable interactions between char functional groups and the bitumen matrix, particularly in GS + HDPE composites, suggesting chemical compatibility. Phase separation analysis demonstrated excellent storage stability up to 12% char content. ANOVA results confirmed that both char type and dosage significantly influenced viscosity and softening point, with GS + HDPE identified as the most effective blend. Furthermore, Marshall stability tests on DBM Grade II mixes with optimized char blends showed superior load-bearing and flow characteristics. Overall, the study demonstrates the improved performance of bitumen modified with co-pyrolyzed agro-plastic char, promoting viable infrastructure through the valorization of agricultural and plastic wastes.

In the current era of energy transition, the developmentof syntheticfuel production pathways has revolutionized the prospects for sustainingcarbon-based hydrocarbon fuels in the transportation sector. Notably,technologies such as Power-to-X (PTX) and biofuels have emerged aspromising solutions, fostering cleaner fuels with reduced carbon intensity.However, it is imperative to note that synthetic fuels like e-gasoline,e-ATF, and e-diesel generated via PTX methods, along with biofuels,may possess distinct physiochemical properties compared to their conventionalcrude oil-derived counterparts. Achieving the requisite fuel quality,performance standards, and adherence to stringent environmental regulationsdemands the incorporation of environmentally friendly additives. Thisreview aims to offer a comprehensive review of potential green additivesfor use in synthetic and biofuels, ensuring that they meet necessaryfuel properties and performance criteria. This approach not only addressesthe immediate need for cleaner transportation fuels but also alignswith the global imperative of achieving net-zero emissions targets.

Environmental regulations restrict the use of high-sulphur petroleum coke as a solid fuel due to the emission of a substantial amount of sulphur oxides (SOx) upon combustion. Therefore, the free sulphur present in petroleum coke needs to be reduced to achieve lower SOx emissions. This paper describes a novel and efficient method for the trapping of free sulphur in petroleum coke during its formation from vacuum residue in the presence of an additive. Among the various additives tested, calcium oxide (10 wt%) was found to be most effective for maximum trapping of free sulphur in petroleum coke. This sulphur-trapped petroleum coke reduces SO2 emissions by 67% upon combustion; hence, it can be used as a better fuel than regular high-sulphur petroleum coke. Thus, by replacing regular petroleum coke with this newly developed sulphur-trapped petroleum coke, environmental pollution can be reduced significantly.

Summary In this paper, we investigate the role of asphaltenes derived from heavy crudes, which dictates the behavior of crude mix properties for hassle-free downstream refinery operation. Combined characterization techniques such as proton nuclear magnetic resonance (1H-NMR), cross-polarization magic-angle-spinning carbon-13 (CP/MAS 13C)-NMR, heteronuclear single-quantum coherence (HSQC), Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) are used for the detailted study of Ratwai and Ras Gharib (RG)-derived asphaltenes to validate their structural role in selecting the optimal crude mix. As per our investigation, when the polyaromatic core of asphaltene structures are less substituted, the availability of aromatic hydrogen is more; it exhibits a stable crude mix as compared to heavy crudes that have more aromatic core substitution, despite the crudes possessing similar asphaltene content and physicochemical properties. This finding is further extended to West Canadian (WC) and Belayim (BL) heavy crudes for operational suitability. In this study, the key feature is to develop a CP/MAS 13C-NMR-based robust and quick characterization technique that could potentially become a prescreening method to assess crude oil compatibility and its various blend processability in the refinery system. Other characterization techniques, such as 1H-NMR, HSQC, FTIR, TGA, and XRD, would corroborate and confirm the reliability of the data obtained by CP/MAS 13C-NMR.