BI-OPTIMIZATION OF DURABILITY AND RHEOLOGICAL PERFORMANCE OF OIL WELL CEMENT SLURRY USING LOCALLY SOURCED EXTENDER

Bentonite used during drilling and cementing operations in Nigeria are imported into the country despite the availability of this raw material, which will increase the Gross Domestic Products (GDP) of this country if properly processed and utilized instead of imported bentonite. This investigation evaluated the performance of three selected Nigerian bentonites sourced from the South-Western part of Nigeria for oil well-cementing operation. The raw and beneficiated samples from each location were prepared and characterized using X-ray Fluorescence (IVT-20 XRF) to determine the elemental composition of each sample pre and post beneficiation. The beneficiated sample with properties close to that of Wyoming bentonite was chosen for the oil well cement slurry analysis. The measured parameters used in the analysis of the suitability of local samples used in oil well-cementing operation were compressive strength and rheological properties. Box-Behnken Design (BBD) was used for the study of the optimum quantity of bentonite required for cementing specification and bi-optimization values for both the comprehensive and rheological properties. The results of this investigation showed that all local clay samples in raw form failed the specification of the American Petroleum Institute (API). After beneficiation, Ibeshe Bentonite (IB) had the highest sodium content and the ratio of the exchangeable cations, 190% increment in sodium-ion was recorded in IB after beneficiation and the slurry yield of IB (2.7 ft3 per sack) was greater than that of  Wyoming Bentonite 1.9 ft3 per sack) when both are subjected to the same experimental condition. Bi-optimization models predicted optimum experimental conditions with an accuracy of between 0.35 and, 1.26 % for both comprehensive and rheological parameter

Synthesis, characterization, and adsorptive performance of titanium dioxide nanoparticles modified groundnut shell activated carbon on ibuprofen removal from pharmaceutical wastewater

In this study, Titanium dioxide Nanoparticles (TiO2 NPs) were biosynthesized using the extract of Cola nitida (Kola nut) pod as a reducing agent. The synthesized TiO2 NPs were impregnated on the surface of Groundnut Shell Activated Carbon (GNSAC) to produce TiO2-NPs-GNSAC, and its performance on the removal of ibuprofen from pharmaceutical wastewater was investigated. The two adsorbents (GNSAC and TiO2-NPs-GNSAC) were characterized using proximate analysis, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), Brunauer-Emmett-Teller (BET), and Energy Dispersive X-ray (EDX). Physical properties such as moisture content, ash content, and volatile matter content were also determined. The combined effects of three independent variables (temperature, time, and adsorbent dosage) were evaluated in a batch study designed through Box Behnken Design (BBD) of the Response Surface Methodology (RSM) for experimental design, analysis, and process optimization. Regeneration examinations were conducted for three cycles. The proximate analysis showed that GNSAC and TiO2-NPs-GNSAC have 63.21 and 71.11 % of carbon, respectively, which could be attributed to the high organic content in Groundnut Shell (GNS). BET analysis proved that the adsorbents (GNSAC and TiO2-NPs-GNSAC) were mesoporous with mean pore sizes of 6.046 and 5.353 nm, respectively. At optimum conditions of 0.62 g/L, 30 °C and 30 min for adsorbent dosage, temperature, and time, respectively, 68.53 % of ibuprofen was removed using GNSAC, while 81.78 % of ibuprofen was removed at optimum adsorbent dosage, temperature, and time of 0.5 g/L, 30 °C, and 50 min, respectively, using TiO2-NPs-GNSAC. Langmuir isotherm best described the equilibrium data using GNSAC and TiO2-NPs-GNSAC, with maximum monolayer adsorption capacities of 40.82 mg/g and 55.56 mg/g, respectively. Pseudo second-order kinetic model was more suitable to predict the experimental data. The mean free energy (E) values of 0.345 and 0.746 KJ/mol obtained for ibuprofen adsorption onto GNSAC and TiO2-NPs-GNSAC indicate that the mechanism of adsorption of ibuprofen follows the physisorption process. Based on the thermodynamic investigation of the current process, it can be concluded that the adsorption of ibuprofen by the prepared activated carbon (GNSAC and TiO2-NPs-GNSAC) was a spontaneous and endothermic process. Additionally, the adsorbent was successfully regenerated three times, and it was able to perform the adsorption and desorption processes well. Hence, the results of this work suggest that the activated carbon prepared from groundnut shell is a suitable adsorbent for the adsorption of ibuprofen from pharmaceutical wastewater

A Multi-objectives regression, optimization and risk assessment of profitability indicators of the simulation of mini Liquefied Petroleum Gas (LPG) dispensing unit

In this study, simulation of a mini Liquefied Petroleum Gas (LPG) dispensing unit was conducted using ASPEN HYSYS and the operation of both compressor and pump were validated theoretically. The effect of the economic parameters (Total Annual Sales (TAS), Total Production Cost (TPC), Fixed Capital Investment (FCI) and interest rate (r)) on the behaviour of three profitability indicators (Net Present Value (NPV), Return on investment (ROI) and Internal Rate of Return (IRR)) were modelled and optimized using Box Behnken Design (BBD). The uncertainty of the developed models was determined using Oracle Crystal Ball (ORB). The optimum economic parameters, TAS of ₦48,830,600, FCI of ₦37,422,000, TPC of ₦35, 053,000 and r of 5.4% predicted optimum profitability indicators are ROI of 34.6%, NPV of ₦98,993,580.25 and IRR of 34.15% for 15 years’ investment plan. An interaction of the economic parameters showed that for NPV to be positive, TAS value should be greater than ₦42.5 million and the TPC should be less or equal to ₦36 million. The profitability analysis suggested that this investment will pay back in 2.36 years. Given that the demand of LPG is on the increase and therefore, this LPG plant will be a long term investment with a good return on investment