Chigozie Francolins Uzoh

The efficient separation of water from crude oil remains a critical operation throughout petroleum production, transportation, and processing. During production and handling, intensive mixing, pres...

This study investigates the rheological behavior, functional group chemistry, and hole-cleaning performance of water-based drilling muds formulated with Xanthan gum and Ogbonno (Irvingia gabonensis) as viscosifiers. Four mud samples were prepared: Sample A (Xanthan gum 2 g), Sample B (Ogbonno 2 g), Sample C (Xanthan gum 2 g + Ogbonno 2 g), and Sample D (Ogbonno 6 g). Aging tests revealed a substantial viscosity decline for Sample A (67% over 5 days) but a more stable profile for Sample B, indicating Ogbonno’s superior temporal stability, while density remained largely unchanged across all samples. Rheological measurements fitted to the Herschel–Bulkley model showed distinct flow characteristics: Sample A exhibited strong pseudoplasticity and high hole-cleaning potential, Sample B near-Newtonian behavior, Sample C high yield stress with reduced shear-thinning, and Sample D a balanced combination of consistency and shear-thinning. Hole-cleaning capacity, ranked from highest to lowest, was Sample A > Sample D > Sample C > Sample B. FTIR analysis confirmed hydroxyl and ether functional groups in both viscosifiers, supporting hydration and viscosity for cuttings suspension. Xanthan gum exhibited higher carboxylate and glycosidic content, enhancing gel strength and shear-thinning, while Ogbonno showed strong O–H and C=O absorption bands, indicating effective water-binding and gel formation. These findings demonstrate that careful selection and concentration of viscosifiers, informed by both rheological and molecular properties, can significantly improve cuttings transport and suspension in water-based drilling fluids.

The major problem of crude oil (CRO) transport through pipelines is wax crystallization and deposition. Flow improvers are added to waxy CRO in order to reduce handling cost. Bio-based flow improvers derived from cheap renewable resources are attractive as cost-effective, eco-friendly alternatives to the conventional additives. Soybean oil (SBO) and castor oil (CAO) was derivatized and applied as bio-based flow improver for waxy CRO. The SBO, CAO and the CRO used in this study were characterized for their fatty acid using a gas chromatograph equipped with a flame ionization detector (FID). Effectiveness of SBO and CAO as flow improver was studied in terms of flowability (% viscosity reduction) and rheological (% gel strength reduction) properties at four operational variables: temperature (30–40 °C), additive concentration (0.1–1.9v/v), shear rate (30–100 rpm), gelling time (0.2–10 min). Experiments were conducted as per central composite design (CCD), and the data was used for model building. Optimization via response surface methodology (RSM) was studied where percentage (%) viscosity and gel strength reduction were monitored as responses from the finding equations of the CCD. The effect of SBO and CAO as a flow improver on the CRO was analyzed in comparison with Xylene. The bio-based treated CRO showed a remarkable improvement in flow characteristic of the CRO. The transition to the optimum % viscosity reduction of 82.58% (SBO), 87.71% (CAO), and 85.25% (Xylene) were achieved at a temperature of 30^oC, additive concentration of 0.1(v/v), gelling time of 5.1 min and the shear rate of 65 rpm for SBO and CAO, but 82.2 rpm for xylene. Similarly, the optimum % gel strength reduction of ≥ 94% for SBO and CAO, but for 95% (Xylene) were achieved at a temperature of 33^oC, additive concentration of 0.1(v/v) for SBO and CAO but 0.56 for xylene, gelling time of 10 min for SBO and CAO but 9.38 for xylene and the shear rate of 30 rpm for SBO, 45.46 for CAO and 43.73 for xylene. Corresponding experiments conducted with these optimal conditions show that the actual results of % viscosity (82.58, 87.71 and 85.25%) and % gel strength (94.36, 94.89 and 95.79%) for SBO, CAO and xylene respectively, were in reasonable agreement with the theoretical results of RSM % viscosity (85, 83 and 87%) and % gel strength (95, 96.5 and 98%) for SBO, CAO and xylene, respectively. The study demonstrated the potential of bio-based additives as viable alternatives to conventional flow improvers for waxy crude oil.

Alkyd resin polycondensation process has been subjected to extensive theoretical, mathematical, experimental and simulation research because of inadequate kinetic models. The analysis of the alkyd resin polycondensation process is outstandingly essential for the design and development of new resins suitable for a broad range of application. However, experimental methods do not only consume time but burdensome, clumsy and costly. Researchers have, therefore, introduced mathematical modeling to control the alkyd reactor polycondensation processes and to investigate and improve the fundamental understanding of the dynamics of the polymerization process, to design new alkyd resin in a shorter time with comparatively lower cost. The latest developments in the mathematical and simulation technologies that have been reported for the alkyd reactor polycondensation kinetics were reviewed. The scope of this review includes the modeling and simulation techniques used for alkyd resin polycondensation processes and future challenges.

Uncoated urea, when applied to crops is susceptible to losses from volatilization, leaching, nitrous emission and water eutrophication. Plants require varying quantities of nutrients during different stages of growth; they need smaller amounts during infancy and larger amounts during the development of roots, stalk and stem. In this research, controlled release coated urea (CRCU) was synthesized via encapsulation with starch- polyvinyl alcohol biocomposite (St-PVOH). Lag, constant and decay release characteristic of the CRCU were simulated using different empirical models as a function of coating thickness. Structural elucidation and morphology of the raw urea and CRCU were determined using FTIR and SEM analytical techniques, respectively. FTIR confirm esterification reaction for St-PVOH. The SEM image of the raw urea appears rough and have fine openings while that of CRCU possesses a seemingly decrease in membrane porosity, ordered and uniform layer. This characteristic qualifies the CRCU as a semi-permeable membrane. Simulation results revealed that coating thickness of 4.3 and 6.4 are best desirable in designing a CRCU for plant at infancy stage, root, and stalk and stem development. Overall, sigmoidal law shows best robust prediction to expanded varying coating thicknesses.

Efficiency of electrocoagulation process for the removal of heavy metals (Pb²⁺, Mn²⁺, and Co²⁺) from simulated wastewater was investigated using iron electrode pair at five operational variables: pH (2–10), current density (0.076–0.189 A/cm²), inter‐electrode distance (3–7 cm), solution temperature (30–70°C), and charging time (5–20 min). Experiments were conducted as per central composite design (CCD), and the data was used for model building. Algorithmic optimization via hybrid response surface methodology (RSM)–genetic algorithm (GA)–particle swarm optimization (PSO) was studied where Pb²⁺, Mn²⁺, and Co²⁺ removal efficiency were monitored as responses from the finding equations of the CCD. Transition to the optimum removal (≥90%) of Pb²⁺, Mn²⁺, and Co²⁺ ions was achieved with current density of 0.19 A/cm², solution temperature of 70°C, mean electrode distance of 3 cm and pH of 6.6 and charging time of 25 min for PSO relative to GA and RSM. Corresponding experiments conducted with the global optimal conditions show that the actual results (98.5, 90, 99%) were in reasonable agreement with the theoretical results of RSM (94.09, 90.82, 85.08%), GA (102.08, 87.91, 101.55%), and PSO (100.58, 90.91, 101.05%) for Pb²⁺, Mn²⁺, and Co²⁺, respectively. The mean error indices of 6.43, 2.83, and 1.73% for RSM, GA, and PSO, respectively, indicate that PSO guarantees best convergences to true optimal.