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We investigated the occurrence of microplastics in samples of borehole drinking water and sediments obtained from borehole sites in Lagos Island, Nigeria. The samples were digested with hydrogen peroxide, pretreated, and filtered through a polytetrafluoroethylene membrane. The filtered microplastics were examined/analyzed under an attenuated total reflection Fourier-transformed infrared device, to quantify the microplastics. The results showed the presence of microplastics in drinking water and sediments from the sites, with plastic concentrations ranging from 206 to 1691 items m

Non admixed Natural gas-fuelled diesel engines are usually associated with harsh engine emissions as well as low performances at moderate to high engine loads. However, the use of Moringa biodiesel as additive in hydrogen-compressed natural gas (HCNG) is a viable novel strategy for reducing toxic emissions such as hydrocarbons and nitrogen oxides in CI engines. In this study, five hybrid HCNG–Moringa biodiesel (MB) oil samples labelled A–E were analysed for their abilities to improve the overall performance of a CI engine (Petter PH1W diesel engine). The fuels had a fixed volume by volume hydrogen : carbon ratio of 87:13% respectively, and the HCNG–MB hybrid samples consisted of 0, 5, 7, 10 and 13 %v/v MB for samples A, B, C, D and E, respectively. At higher engine loads (i.e. 58%–100%), the engine performance improved thus giving higher BTEs in the range of 19–33.9% for all the fuel blends relative to the BTE (15.1%–19%) of the unblended HCNG fuel; this confirms the suitability of MB as an additive for improving the brake thermal efficiency of CI engines; there were also reductions in HC, O2, CO2, CO and NOx emissions for all the MB–HCNG fuels relative to the case of the unblended HCNG fuel. At optimum condition, the fuel that gave the best results in terms of the aforementioned engine characteristics is the MB–HCNG fuel blend having 10% MB.

This research aims to test the suitability of a blend of Camelina sativa biodiesel and acetylated diethyl ether as fuel for compression ignition (CI) engines in terms of engine emission, performance, and combustion properties. A Kiloskar TV 1 diesel engine was used to test the fuel samples: Camelina sativa biodiesel (71% v/v) and dimethyl ether blend (29% v/v) (CD), Camelina sativa biodiesel (71% v/v), diethyl ether (20% v/v), and acetylene (9% v/v) (CDA), and conventional diesel. Based on the analyses, the CDA and CD gave higher BTEs of 4.8 and 3.7% than the diesel fuels. The heat release rates (HRRs) were higher than those recorded for the conventional diesel with a longer combustion duration for the blends. Moreover, the CDA fuel gave the lowest CO2, HC, CO, smoke, and NOx emissions. The resulting peak emissions for the blends are in the following increasing order: unburnt HC (CDA (97)

The adoption of nanodoped membranes in the areas of gas stream separation, water, and wastewater treatments due to the physical and operational advantages of such membranes has significantly increased. The literature has shown that the surface structure and physicochemical properties of nanodoped membranes contribute significantly to the interaction and rejection characteristics when compared to bare membranes. This study reviews the recent developments on nanodoped membranes, and their hybrids for carbon capture and gas separation operations. Features such as the nanoparticles/materials and hybrids used for membrane doping and the effect of physicochemical properties and water vapour in nanodoped membrane performance for carbon capture are discussed. The highlights of this review show that nanodoped membrane is a facile modification technique which improves the membrane performance in most cases and holds a great potential for carbon capture. Membrane module design and material, thickness, structure, and configuration were identified as key factors that contribute directly, to nanodoped membrane performance. This study also affirms that the three core parameters satisfied before turning a microporous material into a membrane are as follows: high permeability and selectivity, ease of fabrication, and robust structure. From the findings, it is also observed that the application of smart models and knowledge-based systems have not been extensively studied in nanoparticle-/material-doped membranes. More studies are encouraged because technical improvements are needed in order to achieve high performance of carbon capture using nanodoped membranes, as well as improving their durability, permeability, and selectivity of the membrane.

Value-focused thinking is often designed to focus our decision on the essential activities that must occur prior to solving a decision problem. This approach was adopted by the Nigerian government in the fiscal legislation for Deep Offshore and Inland Basin Production Sharing Contract (DOIBPSC) Act enacted in 1999 and the subsequent amendment of 2020. One major item of interest in the amended Act is the introduction of royalty by price to enable the government to capture windfall in high oil price spike. This study evaluates the new fiscal regime to ascertain its attractiveness and impact of contractor take. Four features (royalty, cost recovery, tax oil, and profit oil) of the PSC contract terms were used to determine contractor and government takes from the transactions. This study adopted the full range of oil prices captured in the amended DOIBPSC Act in addition to the current market price of oil estimation. Six ranges of oil price ($ 20/bbl, $ 30/bbl, $ 40/bbl, $ 80/bbl, $ 120/bbl, $ 160/bbl) were used to cover the five royalty sliding scales adopted in the amended DOIBPSC and the current oil price during this study which is ≤ $ 20/bbl. From the econometric analysis, estimates from the unit root tests revealed that the time series data are mixture of I(0) and I(1) series. The ARDL/bound cointegration test result shows that all the integrated variables are cointegrated at a 5% level. Analysis of the impact of the price sliding royalty regime on the contractors’ take shows that in both the long run and the short run, the price sliding (royalty by price) regime had a negative impact on the contractors’ take. The short-run impact of the royalty level and the regime change on the contractor’s take is high and significantly negative. This is expected as the design of the royalty regime is based on long term benefits. Keywords: Deepwater fiscal system; Royalty regimes; Production sharing contract; Oil and Gas; Long and short runJEL Classifications: P28, O22, O38DOI: https://doi.org/10.32479/ijeep.11244

Corrosion of mild steel via chemical reaction in a corrosive environment is a problematic occurrence that is very common in oil and gas industries. Corrosion constitutes a huge part of the total costs in the production of oil and gas. Corrosion inhibitors have found interest in the scientific domain because they are mainly understood by their chemical complexes and formulations. Their utilization in small amount on metal surface used in oil and gas industries can help shield the metal from corrosion devoid of any significant alteration in the concentration of the corrosive media in the environment. An effort was made to study the possibility of using calf thymus gland DNA (CTGDNA) inhibitor in chlorine induced mild steel for possible usage in piping in oil and gas industry. The SEM micrograph shows that the adsorption of the CTGDNA biomacromolecules coat on the mild steel surfaces functions as a protection against HCl corrosive solution. Electrochemical study and weight loss analysis showed that the inhibitor efficiency (70.48 and 72%, respectively) of the tested DNA (CTGDNA) in HCl acidic corrosion environment for the mild steel was high at 1.5 M of HCl. The inhibitor efficiency decreased with increasing HCl concentrations. The open circuit potential (OPC) revealed that the mild steels got corroded until the end of the immersion. The intensities of XRD peak substantiate the existence of corrosion products of FeCl2.

Enhanced oil recovery techniques are deployed to subsequently improve oil production having already employed primary or secondary recovery techniques or both methods simultaneously. Literature have shown that salinity impacts on oil recovery due to wettability alteration, but grain size which is closely related to the mechanical behavior and petrographical properties is also one of the main parameters controlling the phenomenon. There is need to investigate the effect of these two parameters in oil recovery. This study considered the effects of water salinity in the range of 0 to 20,000 ppm and sand grains of 45 to 300 μm on oil recovery. Flooding experiments and statistical analyses of the designed experiment was used to determine the residual oil saturation. The properties of sand samples such as bulk and pore volumes, porosity as well as, wet and dry weight for the various groups were also analyzed. Gauss-Newton algorithm with Levenberg-Marquardt modifications were the numerical scheme executed in MATLAB to formulate residual oil saturation model. The optimum percentage recovery for the core flooding experiment in each groups are 82.4%, 81.1%, 79.4%, 81.1% and 78.8% for A4, B4, C4, D4 and E5 respectively. Based on the experimental results, the 300 μm sand grains and salt concentration of 15,000 ppm should be used for operations in this reservoirs because, those conditions guarantee oil recovery as high as 82%. High oil recoveries correspond to low residual oil saturation and vice-versa. The recovered residual oil percentage had no direct correlations with the net dry and wet weights of the samples. The 45-micron grains had the least pore volume and it was observed that the percentage recoveries had no direct correlations with the core sample weights. During validation of the formulated residual oil saturation model, the model gave a good prediction of the experimental data within the 95% confidence interval, and from the statistical analyses, residual oil saturation decreased with decrease in water salinity. Thus, the larger the size of a grain, the lower its superficial area exposed to the wetting and non-wetting fluids which subsequently impacts on oil recovery.

Different concentrations of Citrus aurantium with deoxyribonucleic acid as additive (Citrus aurantiumDNA) were co-deposited with nickel via electrodeposition. The coatings were formed in an aqueous nickel bath with the incorporation of Citrus aurantiumDNA concentrations at different temperatures, and the influence of the acid and the temperature on the microstructure of the coatings was studied. The data via adsorption isotherms were also analyzed. The characteristics of the morphological structure of the coatings were examined by scanning electron microscopy. The results demonstrated that Citrus aurantiumDNA additives were evenly dispersed on the mild steel surface during the nickel coatings deposition; a current density of 1.5 A/dm3 used during the electrolysis process was favourable in attaining the maximum coating efficiency (~70%) at 25°C and 20 mg/L of Citrus aurantiumDNA. The optimum temperature for electroplating was found to be 25°C. The data spawned from the adsorption Freundlich and Langmuir isotherms showed two preferred temperatures: i.e. 25 and 40°C via the former and 55 and 70°C via the latter. The thermodynamic assessment confirms that the adsorption mechanism of the Citrus aurantiumDNA additive in a Ni electrolyte solution on mild steel in an HCl solution is physisorption at the investigated temperatures. X-ray diffraction revealed some broad peaks signifying an amorphous structure at all Citrus aurantiumDNA concentrations.

The ever-increasing CO2 emission has necessitated the search for suitable technologies for CO2 utilization at a low cost. Recently, a novel concept called reactive gas electrosorption (RGE) for energy harvesting from CO2 emission, which could boost the efficiency of a thermal power plant by 5% was proposed by Hamelers and coworkers. The concept involves mixing of air stream with a low CO2 concentration with a stream of high CO2 concentration in an alkaline aqueous electrolyte. However, this concept is faced with the challenges of designs specific for CO2-electrolyte, and inadequate performance of the electrode materials. Therefore, this study showcases electricity generation opportunities from CO2 via RGE and discussed challenges and prospect. The study reveals that the drawback relating to the electrode could be solved using heteroatom doped traditional carbon materials and composite carbon-based materials, which has been successfully used in capacitive cells designed for desalination. This modification helps to improve the hydrophilicity, thereby improving electrode wettability, and suppressing faradaic reaction and co-ion repulsion effect. This improvement could enhance the charge efficiency, sorption capacity durability of electrodes and reduce the energy loss in RGE. Moreover, intensification of the membrane capacitive deionization (MCDI) process to obtain variances like enhanced MCDI and Faradaic MCDI. Hybrid capacitive deionization (HCDI) is also a promising approach for improvement of the capacitive cell design in RGE. This intensification can improve the electrosorption capacity and minimize the negative effect of faradaic reaction. The use of alternative amine like Piperazine, which is less susceptible to degradation to boosting CO2 dissolution is also suggested.

Contaminated natural gas when carelessly handled, often poses human and equipment related problems ranging from lung and skin infections to corrosion, equipment fouling/failure and reduction in gas quality owing to the presence of acid gases. In this work, four natural gas (NG) samples were treated to remove CO2 and H2S using 10–50% Di-Ethanolamine (DEA) solutions mixed with 5% w/w 0.1 M calcium hydroxide. The treatment process gave increased acid gas removal at increased DEA concentrations. Based on the simulation results, cost effective treatment of the gas samples, require 0.1 M Ca(OH)2 and DEA mixed solutions in the range of 27.4–30%. The optimum mixture concentration for the gas treatment was found to be 30% Ca(OH)2-DEA hybrid solution with feed gas flow rate of 830 kscf/h. In terms of pressure energy consumption, pumping the hybrid mix at 830 kscf/h will save pressure energy as compared to pumping the feed gas at 1024.58 kscf/h since the lower and upper limit feed gas flow rates gave similar results. The optimum pressure for NG treatment was found to be in the range of 2–2.7 bar (2–2.7*105 kgm−1 s−2). Keywords: Absorption, Acid gas, Gas treatment, Process optimization, Process simulation

Conventional methods of eliminating water from crude oil such as the chemical injection have both economic and environmental impacts; thus, this study proposed an economic and environmentally friendly demulsifier. The bottle test method was used to study the performance of the natural extract and commercial demulsifier on a crude oil sample. The GC-MS profile of the extract was in agreement with previous reports on composition of oil extracted from rice bran using hexane, ultrasound assisted extraction and conventional solvent extraction with ethanol. Varying degrees of saturated and unsaturated fatty acids as well as retention times as observed, was a function of total time of scanning, according to NIST08 library of mass spectra. The performance of the demulsifier was expressed in terms of percentage of water separated from 100 ml samples of the oil samples. For both the demulsifiers, the performance increased with increase in volume of the demulsifier, separation time and operating temperature. The extracted demulsifier performed better than the chemical demulsifier under all the experimental conditions adopted in this study. Based on the parametric evaluation, it was observed the results from software corroborated the results obtained from experiments in terms of the observations of the combined effect of temperature and volume which showed the most significant influence on demulsification of the emulsified crude. The highest efficiency of the bio-demulsifier was obtained with a volume of 5 mL of the extract, at a temperature of 70°C and separation time of 60 min. A water separation efficiency of 85.6% was obtained as compared to the chemical demulsifier, which gave an efficiency of 80.2%.

In a bid to complement the lost reserves from fossils, recent advances in research are tailored towards producing hydrogen as an alternative source of fuel which is aimed at fostering a globally sustainable and reliable energy-economy. In this work, hydrogen was produced from formic acid (FA) using a new technology that involves the use of copper nanoparticles (CuNPs) supported on triethanolamine. The CuNP-catalysts of variant concentrations (i.e. 0.6–1.2 M) were synthesized using the conventional chemical deposition method. Also, a novel approach that bothers on the application of the Differential Method of Analysis (DMA) was used in determining the kinetic parameters for the FA-dehydrogenation. Based on the results, the volume of H2 produced varied with time, pH, concentration and catalyst-size. At 6 h, the 1 M CuNPs gave the highest volume (815 mL) of hydrogen with corresponding pH, particle size and approximate conversion of 3.19, 1.5 nm and 100% respectively, whereas, over extended periods i.e. over 6 h, the approximate volume-conversions of FA increased insignificantly for all catalysts. According to the investigation, the optimum CuNP-catalyst concentration required to produce 815 mL H2 in 6 h is 1 M. The decomposition was a first-order-type with a rate constant (k-value) of 1.0041 s−1.

Adsorption of caffeine from an aqueous solution was carried out using Velvet Tamarind-Pericarp, activated with H

Naturally occurring radioactive materials (NORMs) and the presence of toxic metals in drilling fluids/their additives have raised research interests in recent times owing to the risks associated with the exposure times for drillers of petroleum wells. In this study, two drilling fluids A and B were formulated, while two other Mud Samples C and D were obtained from drilled shale and shale-sand formation zones. All four fluids were collected and analyzed for the presence of radioactive and heavy metals. Lead (Pb), mercury (Hg), cadmium Cd), zinc (Zn), chromium (Cr), aluminum (Al), arsenic (As), nickel (Ni), and copper (Cu) were detected in the mud samples. The heavy metal contents of the mud samples are in the following decreasing order of magnitude Hg > Pb > Cd > Cr. In Samples A–D, Hg, Pb, Cr, and Cd were found to have significant concentrations, and the concentrations of these metals increased in the mud samples after they were used for drilling. The concentration of Hg was above the permissible limit. Also, the concentrations of Pb, Cu, As, and Al found in Mud Samples A and B can cause skin irritations over long-term exposures, while Cd, Hg, Zn, and Ni present in the samples were within levels that can cause lung infections or immune breakdown when ingested over long periods. The quantities of Cd, Hg, and Cu detected in Mud Samples C and D can cause skin irritations over long-term exposures, while those of As, Zn, Ni, and Al were seen to have the potential to cause dermal infections/diseases. Based on the results obtained, the cancer risk for the drilling crew lies within 1.1 × 10−3 - 7.7 × 10−3 HQ. The highest dose rate, radium release, and external hazard index were obtained for Mud Sample C whose radium equivalent was judged to be far below the critical safe limit for the drillers. The radium equivalent activity for the two field mud samples (C and D) were estimated to be 27.467 and 22.978 Bq kg−1, respectively, which is the maximum activity obtained for the analyzed samples. The maximum radium equivalent activity for Mud Sample C was estimated as 27.48 Bq kg−1 with a corresponding external hazard index of 0.7. Based on the analysis, there is a significant correlation between the concentration of heavy metals and the radionuclides found in the mud samples.

Vapour compression systems are designed to use refrigerants and lubricants for smooth performance. However, recent advances in nanoparticles research have led to the use of Cu and Ag-nanoparticles (AgNPs and CuNPs) as compressor fluid modifiers. In this study, several concentrations of AgNO3 and CuSO4 solutions were adopted in synthesizing nanoparticles for use in a compressor oil. The optimum Coefficient of Performance and cooling effect of the system were observed at optimum concentrations of 0.08 and 1.6 M for the Ag- and CuNP- lubricating oils, respectively, thus giving better cooling effects than the ordinary Copeland 46B oil. At optimum conditions, the weakly acidic CuNP-oil performed better than the weakly alkaline AgNP-oil with cooling temperatures of −8 and 2.3 °C, respectively. Equilibrium concentrations for both particulate oils were found to be 0.08 and 2.7 M at the same yield stress of 2 lb./100 ft2, while the lubricities of the oils ranged from 0.119–0.154, 0.134–0.155 and 0.156–0.180 for the CuNP-, AgNP- and Copeland 46B oils, respectively. Since lower lubricities are indicative of better lubrication, it then implies that the CuNP-oils gave the best lubricities. An increase in the motor speed gave a corresponding increase in the torque generated as well as, the lubricity coefficients and lubricities of all the oils. Enthalpy changes ranged from 70.3–520 Jg/mol for the 1.1–2.1 M CuNP-oils, although, it was very high (4523.5 Jg/mol) for the 2.7 M CuNP-oil which may be due to the superficial distribution of copper as well as its large surface area to charge ratio at the oil surface, thus making it a better conductor of heat relative to the AgNP-oils. For the AgNp-oils, the enthalpy changes were very small i.e. from −1.012 – 1.2957 Jg/mol whereas, it was 523 Jg/mol for the Copeland oil. Furthermore, the least power consumption was obtained for the CuNP-oils.

The current state of aerosols retention and loading over West Africa requires urgent consideration to avert environmental disaster which include telecommunication degeneration. Research show that atmospheric aerosol leads to high light signal absorption. In this paper it is proposed that atmospheric aerosols are impactful on tropospheric radio wave propagation at a certain aerosol loading condition. Sokoto, Nigeria was considered because of its proximity to Sahara Desert. It is located on longitude 5.15°E and latitude 15.05°N on the sahelian plain. Analytical and statistical model were used to estimate the aerosols retention and loading respectively. The chaotic solution of the particulate influence on signal was numerically proven. Aerosols retention and loading effect on surface temperature was significant. The speed of the particulate distribution clearly show that atmospheric aerosols are impactful on tropospheric radio wave propagation. It was observed that tropospheric radio wave propagation depends on the volume of aerosols loading not on the attenuation due to particulate velocities. Hence, the continued signal attenuation of tropospheric radio wave propagation due to atmospheric aerosols in high prone areas must be considered during signal budgeting.

A Nonlinear Regression Analytical model was used to simulate the corrosion rate of CO2 flowing through a pipeline at different operating conditions. The model was formed by applying the simple current-resistance relationship which was further simplified to obtain an appropriate expression for estimating the corrosion rate of a pipeline in relation to the partial pressure of the gas at different temperatures (30–37 °C). Field conditions were validated against simulated results and based on the findings, the model proved to be an accurate tool for determining the corrosion rate of CO2 for curvilinear pipe of 3 km length transporting fluids having similar gas composition. Based on the estimated corrosion rates, the model's accuracy lies in the range of 96–99%. Also, from the results, there seem to be an approximate linear relationship/positive correlation between the corrosion rate of CO2 and, the system temperature and CO2 partial pressure.

In recent times, graphene, a super-carbon-based nanomaterial, has spurned research interests because it is the most important of the list of available carbon nanomaterials, has distinct properties, has significant impact in human lives, is biodegradable, and finds application in various disciplines, including physics, chemistry, engineering, biomedicine, biotechnology, etc. It is a two-dimensional monolayer material characterized by sp2 hybridized carbon atoms arranged in a honeycomb lattice/hexagonal array. Its usefulness or functionality is enhanced by the ease with which it undergoes chemical modification to suit a particular application. The new technology behind the synthesis of graphene and its derivatives is benign (green), which complements its wide use. For future applications, its prospective use requires detailed understanding of the technology behind its formation. Its kinetics, anticorrosion properties and photoluminescence mechanism, and how they compare favorably with those of carbon and polymer nanodots (nanoparticles) are also currently being experimented. There are enormous justifications why graphene has gained alarming interest in the fields of science and engineering and some of them include its outstanding carrier mobility, transconductivity, ultimate thickness, and stability. In this chapter, the following subsections shall focus on the nature, chemical structure, properties, synthesis, and applications of graphene and its composites.

Microbialcorrosionoftheexternalsurfaceofcarbonsteelpipeswasinvestigatedusingsodiumtungstate,sodium nitrite and zinc nitrite as individual and combined inhibitors. The study involved carbon steel pipes in contact with Acidithiobaccillus thiooxidan. Inhibitor efficiencies were determined and the optimum inhibitor concentration required to effectively limit the corrosive effect of the microbe was 51–52g/L for the best inhibitor. Also, despite the limiting effect of sodium nitrite in its other inhibitor formulations, its presence in the mixture of all three components, improved the performance of the other two chemicals giving the best inhibition efficiency of 85.68%.

The structural complexities in lanthanum cuprates family were revisited with the aim of understanding factors that structurally triggers long-range repulsive Coulomb interactions. In this study, polycrystalline samples of La2SrDyCu2Oy (LSDCO) were prepared via solid-state synthesis using high purity chemicals. The X-ray diffraction experiment revealed an unusual structural anomaly in the [2 0 5] and [2 1 3] planes of the crystal lattice. The lattice system was further probed using the Niggli-reduced cell at gamma = 6.0678. It was observed that grain boundaries leading to electron trapping originates from the CuO2 plane while the mesoscopic phase separation is controlled by the cell type and axial value in the x- and y-axes of the crystal lattice. Although the research partly supports popular findings that the main positive lobes of LSDCO are centered on the z-axis, it observed that the negative lobe is located in a ring-like structure along the X Y plane. This result is particularly interesting because it shows the likely origin of broken symmetry in LSDCO sample. The ion bombardment analysis shows that the LSDCO electron-phonon ratio was 8:5. The microstructural analysis of the LSDCO sample was observed to have magnetic field strength of 1.5 kA/m. LSDCO sample possess enormous structural mystery that may interest further studies beyond superconductivity.

The presence of carbon dioxide (CO2) in oilfield produced water, which could be natural or intentionally injected component in oil and gas production, is extremely corrosive to pipelines and tubing...

Bitter leaf and Fenugreek seed oils were extracted from their parent seed plants for use as corrosion inhibitors for mild steel in HCl. Corrosion measurements were taken at a time interval of 72 h. The Fenugreek seed oil gave 90% efficiency with a regression coefficient of 0.99 in terms of its ability to resist HCl corrosion, while the bitter leaf oil extract gave a corrosion inhibition efficiency of 87% with a regression coefficient of 0.84. Based on analyses, the adsorption of the extracts to mild steel obeyed better, the Langmuir adsorption isotherm. From the calculated ∆Gs, the adsorption of Fenugreek and bitter leaf oils on the surface of the mild steel as corrosion inhibitors, were found to be clearly descriptive of physiosorption and chemisorption respectively. Furthermore, the FLE and BLE adsorption behavior on the mild steel can be described as that of mixed-type inhibitor. Based on the phytochemical test conducted, the better performance of the FLE relative to the BLE may be as a result of terpenoids which are present in the FLE.