Mathematical Model of a Tiny Fluid in Porous Media. Spilled Oil as a Case Study

A dynamic model for the movement of spilled oil through a porous medium was developed. The equation being non-linear partial differential equation and parabolic forms, was thus solved numerically with the adoption of the Crank Nicholson finite difference scheme. A mathematical algorithm to solve this system of equation was developed and implemented into simulation program. The graph of the concentration against axial distance (height), concentration against radial distance at different time were plotted from simulation results obtained which shows decrease in the concentration of solute (contaminant) through the media

OPTIMIZATION OF BIODIESEL PRODUCTION FROM WASTE FRYING OIL OVER ALUMINA SUPPORTED CHICKEN EGGSHELL CATALYST USING EXPERIMENTAL DESIGN TOOL

An optimization of the biodiesel production from a waste frying oil via a heterogeneous transesterification was studied. This present study is also aimed at investigating the catalytic behaviour of the alumina supported eggshell (ASE) for the synthesis of biodiesel. A synthesized ASE catalyst, at various mixing ratios of alumina to eggshell, was investigated and exhibited a better activity for the reaction when the eggshell and alumina were mixed via incipient wetness impregnation in 2 : 1 proportion on a mass basis and calcined at 900 °C for 4 h. The as-synthesized catalyst was characterized by basicity, BET, SEM, EDX, and FTIR. The 2k factorial experimental design was employed for an optimization of process variables, which include catalyst loading, reaction time, methanol/oil molar ratio and reaction temperature and their effects on the biodiesel yield were studied. The optimization results showed that the reaction time has the highest percentage contribution of 40.139% while the catalyst loading contributes the least to the biodiesel production, as low as 1.233 %. The analysis of variance (ANOVA) revealed a high correlation coefficient (R2 = 0.9492) and the interaction between the reaction time and reaction temperature contributes significantly to the biodiesel production process with percentage contribution of 14.001 %, compared to other interaction terms. The biodiesel yield of 77.56% was obtained under the optimized factor combination of 4.0 wt.% catalyst loading, 120 min reaction time, 12 : 1 methanol/oil molar ratio and reaction temperature of 65 °C. The reusability study showed that the ASE catalyst could be reused for up to four cycles and the biodiesel produced under optimum conditions conformed to the ASTM standard

Development and Characterization of a Composite Anthill chicken Eggshell Catalyst for Biodiesel Production from Waste Frying Oil

The primary aim of this research is to synthesis composite anthill-chicken eggshell catalyst, which is characterized and employed for the synthesis of biodiesel from waste frying oil. The as-synthesized catalyst was characterized using various characterization techniques, such as Xray fluorescence (XRF), Fourier transform infrared radiation (FTIR), Brunauer–Emmett–Teller (BET) analysis, scanning electron microscopy (SEM), and Basicity. The influence of different reaction parameters on the catalytic reaction, reaction time, catalyst loading and reaction temperature in the range of 50–75°C were studied at fixed methanol/oil ratio of 6:1. The experimental data obtained showed that at reaction time of 2 h, catalyst loading of 5 wt% and reaction temperature of 60°C, the biodiesel yield was 70%. The synthesized catalyst was found to convert low-grade oil into biodiesel via a single-step transesterification process, and its activity has the potential for improvement

Adsorption of hexavalent chromium from aqueous solution by Leucaena leucocephala seed pod activated carbon: equilibrium, kinetic and thermodynamic studies

This study is initiated to launch an activated carbon derived from Leucaena leucocephala seed pod as an adsorbent for the removal of hexavalent chromium from aqueous solution. The prepared activated carbon was characterized by proximate analysis, Brunauer-Emmett-Teller (BET) surface area measurement, scanning electron microscopic-energy dispersive X-ray (SEM-EDX) spectroscopy and Fourier transform infrared (FTIR) spectroscopy. The effects of various variables, initial Cr(vi) concentration, contact time, adsorbent dosage, temperature and pH, which influence the adsorption process, were investigated. Equilibrium adsorption isotherms, kinetic and thermodynamic behaviour of the process were studied. The pH at point of zero charge (pHpzc) of 5.20 suggested that surface of the activated carbon was positively charged for pH below the pHpzc, attracting anions. The obtained results showed that 100 min contact time, 1.0 g adsorbent dose, 45 °C temperature and solution pH of 6.0 resulted in maximum Cr(vi) uptake. The experimental data better fitted to the Langmuir isotherm with monolayer adsorption capacity of 26.94 mg/g. The kinetic analysis revealed that pseudo-second-order model fitted well to the acquired experimental data. The thermodynamic behaviour of Cr(vi) adsorption onto activated carbon was found to be spontaneous and endothermic in nature

Optimization of adsorption of Cr(VI) from aqueous solution by Leucaena leucocephala seed shell activated carbon using design of experiment

Abstract The activated carbon from Leucaena leucocephala seed shell was prepared by chemical activation, characterized and used as adsorbent for the removal of hexavalent chromium [Cr(VI)] from aqueous solution via batch mode adsorption. The variables affecting the adsorption process, initial adsorbate concentration, pH, adsorbent dosage and temperature were optimized using central composite design (CCD) of the response surface methodology (RSM) at fixed contact time of 60 min. Equilibrium adsorption isotherm and kinetic were also studied. The analysis of variance (ANOVA) revealed that all the variables studied had significant effects on the removal efficiency of Cr(VI). The obtained data showed that 71.49 mg/L initial Cr(VI) concentration, 4.22 solution pH, 0.57 g adsorbent dosage and 26.2 °C temperature resulted in 95.62% adsorption. Equilibrium adsorption isotherm and kinetic studies showed that Freundlich isotherm and pseudo-second-order kinetic model fitted well to the experimental data. The activated carbon from Leucaena leucocephala seed shell was found to be efficient for Cr(VI) adsorption

Response surface methodology approach to optimization of process parameter for coagulation process of surface water using Moringa oleifera seed

Recent researches have linked the use of synthetic coagulant for treatment of water with some neurodegenerative and neurotoxic diseases. In view of this, this study focused on the use of an eco-friendly natural coagulant, Moringa oleifera seed for the treatment of surface water. In order to obtain lowest turbidity of surface water, optimization of process variable affecting the coagulation of water was carried out using Response Surface Methodology (RSM). Four parameters were varied viz. settling time, agitation time, agitation speed and Moringa oleifera seed extract (MOSE) concentration and their effects on the turbidity of the surface water were established. The data obtained was fitted to a quadratic model which was also validated. The model predicted lowest turbidity of 5.49 NTU with optimal condition of 120 min of settling time, agitation speed of 100 rpm, 10 min of agitation time and 3 g/l of MOSE concentration. The condition was verified in replicates and turbidity of 5.51 NTU was obtained. The result obtained from this study could be applied to industrial scale for treatment of water. Keywords: Moringa oleifera, RSM, Surface water, Optimization, Coagulatio

An overview of chemical enhanced oil recovery: recent advances and prospects

Despite the progress made on renewable energy, oil and gas remains the world’s primary energy source. Meanwhile, large amounts of oil deposits remain unrecovered after application of traditional oil recovery methods. Chemical enhanced oil recovery (EOR) has been adjudged as an efficient oil recovery technique to recover bypassed oil and residual oil trapped in the reservoir. This EOR method relies on the injection of chemicals to boost oil recovery. In this overview, an up-to-date synopsis of chemical EOR with detailed explanation of the chemicals used, and the mechanism governing their oil recovery application have been discussed. Challenges encountered in the application of the various conventional chemical EOR methods were highlighted, and solutions to overcome the challenges were proffered. Besides, the recent trend of incorporating nanotechnology and their synergistic effects on conventional chemicals stability and efficiency for EOR were also explored and analysed. Finally, laboratory results and field projects were outlined. The review of experimental studies shows that pore-scale mechanisms of conventional chemical EOR is enhanced by incorporating nanotechnology, hence, resulted in higher efficiency. Moreover, the use of ionic liquid chemicals and novel alkaline–cosolvent–polymer technology shows good potentials. This overview presents an extensive information about chemical EOR applications for sustainable energy production

Application of Polymers for Chemical Enhanced Oil Recovery: A Review

Polymers play a significant role in enhanced oil recovery (EOR) due to their viscoelastic properties and macromolecular structure. Herein, the mechanisms of the application of polymeric materials for enhanced oil recovery are elucidated. Subsequently, the polymer types used for EOR, namely synthetic polymers and natural polymers (biopolymers), and their properties are discussed. Moreover, the numerous applications for EOR such as polymer flooding, polymer foam flooding, alkali–polymer flooding, surfactant–polymer flooding, alkali–surfactant–polymer flooding, and polymeric nanofluid flooding are appraised and evaluated. Most of the polymers exhibit pseudoplastic behavior in the presence of shear forces. The biopolymers exhibit better salt tolerance and thermal stability but are susceptible to plugging and biodegradation. As for associative synthetic polyacrylamide, several complexities are involved in unlocking its full potential. Hence, hydrolyzed polyacrylamide remains the most coveted polymer for field application of polymer floods. Finally, alkali–surfactant–polymer flooding shows good efficiency at pilot and field scales, while a recently devised polymeric nanofluid shows good potential for field application of polymer flooding for EOR