Analysis of clean coal technology in Nigeria for energy generation

Abstract: An analysis of clean coal technologies for the recovery of energy from Nigerian coals was carried out. The coal mines studied are Onyeama, Ogwashi, Ezimo, Inyi, Amasiodo, Okaba, Lafia-Obi, Owukpa Owukpa, Ogboyoga and Okpara. The estimated reserves of the ten coal deposit amount to 2.1 Gt, which is about 84 % of the total coal reserves of the country 2.5 Gt of coal Nigeria. The key clean coal technologies studied are Ultra-Supercritical Combustion (USC), Supercritical-Fluidised Bed Combustion (FBC), Integrated Gasification Combined Cycle (IGCC) and Coal bed Methane (CBM) and the results were compared with conventional subcritical pulverised fuel combustion (PF). The total potential energy recovery from these technologies are: PF 5800 TWh, FBC 7250 TWh, IGCC 7618 TWh, and USC 8519 TWh. This indicates an increase of about 31% in the total electricity generation if USC technology is used instead of the conventional sub-critical PF technology..

Determination of Optimum Conditions for the Production of Activated Carbon Derived from Separate Varieties of Coconut Shells

Activated carbons were produced from coconut shells of tall and dwarf tree varieties. The activated carbon from the tall tree variety was initially synthesized using 1 M concentration of each of ZnCl2, H3PO4, and KOH solutions. From the adsorptive tests conducted using methylene blue solution, the activated carbon produced with H3PO4 gave the best absorbance and adsorptive performance. Coconut shells of dwarf tree variety were then obtained and treated with same mass of coconut shells of the tall tree variety using varied concentrations of the acid in order to determine whether the optimum concentration and temperature for producing carbon black from the coconut shells are distinct or similar for both varieties. The process was also modelled using the Differential Response Method (DRM) in order to determine the yields and adsorptive performances of the activated carbons by varying the carbonization temperature and concentration. The results from experiment and the developed mathematical model were both found to be in agreement giving the optimum concentration of phosphoric acid and pH for producing activated carbon to be 0.67 M and 2.07 for the tall tree variety and 1 M and 1.98 for the dwarf variety at optimum temperatures in the range of 450–575°C and 575°C, respectively

Three-Dimensional FDTD Simulation of Biomaterial Exposure to Electromagnetic Nanopulses

Ultra-wideband (UWB) electromagnetic pulses of nanosecond duration, or nanopulses, have been recently approved by the Federal Communications Commission for a number of various applications. They are also being explored for applications in biotechnology and medicine. The simulation of the propagation of a nanopulse through biological matter, previously performed using a two-dimensional finite difference-time domain method (FDTD), has been extended here into a full three-dimensional computation. To account for the UWB frequency range, a geometrical resolution of the exposed sample was $0.25 mm$, and the dielectric properties of biological matter were accurately described in terms of the Debye model. The results obtained from three-dimensional computation support the previously obtained results: the electromagnetic field inside a biological tissue depends on the incident pulse rise time and width, with increased importance of the rise time as the conductivity increases; no thermal effects are possible for the low pulse repetition rates, supported by recent experiments. New results show that the dielectric sample exposed to nanopulses behaves as a dielectric resonator. For a sample in a cuvette, we obtained the dominant resonant frequency and the $Q$-factor of the resonator.Comment: 15 pages, 8 figure

Improving mechanical and thermal properties of graphite–aluminium composite using Si, SiC and eggshell particles

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Assessment of the Performance of Osmotically Driven Polymeric Membrane Processes

The universal water scarceness and the extensive ordeals with energy cost in conjunction with the undesirable ecological effects have advanced the improvement of novel osmotically driven membrane processes. Membrane processes which are osmotically driven are developing type of membrane separation procedures that apply concentrated brines to separate liquid streams. They are adaptable in various applications; hence, allow them to be an attractive substitute for drug release, wastewater treatment and the production and recovery of energy. Although, internal concentration polarization (ICP) occurs in membrane practises which are osmotically driven as a consequence of hindered diffusion of solute in a porous stratum, their interest has even increased. Here we review two natural membrane processes that are osmotically driven; Forward osmosis (FO) and Pressure retarded osmosis (PRO). Thus, the major points are as follows: 1) it was highlighted in this review, that the major developments in FO process, important for the process efficiency is to choose a suitable membrane and draw solution. 2) The recent evaluation, understanding and optimizing the activities of fouling throughout the osmotic dilution of seawater employing FO was discussed. 3) Recent advancements of FO in the application of food processing was reviewed. 4) It was highlighted that the main concept of PRO for power generation is the energy of mixing that offers great assessment of the nonexpansion work which could be generated from mixing; nonetheless, the development of effective membranes with appropriate arrangement and performance is needed for the advancement of PRO process for power generation. 5) One major challenge of osmotically driven membrane processes, most recent developments and model development to predict their performances were discussed

Protein - Sparing Activity of Lipid and Carbohydrate in the Giant African Mudfish, H. longifilis Diets

In two different experiments on lipid and carbohydrate requirement, H. longifilis was fed diets containing 13.68% to 24.66% of lipid, 17.00% to 20.86% of carbohydrates for 56 days. There was positive response in terms of growth of H. longifilis in the various diets fed in the experiments. There was significant variation (P<0.05) in the specific growth rate (SGR), food conversion ratio (FCR), protein efficiency ratio (PER), apparent net protein utilisation (ANPU) and percentage survival (PS) in the fish fed varying lipid levels. As for the fish fed varying levels of carbohydrates, there was no significant variation (P>0.05) in the SGR and FCR but there was significant variation (P<0.05) in the PER, ANPU and PS. The protein/lipid ratio was 1.58 while the protein/carbohydrate ratio was 2.22. These ratios are very important in the formulation of H. longifilis feed for optimal growth of fish in that protein is spared for growth while the lipid and carbohydrate portions of the diet are used for energy production. @JASE

Fakunle,et al,Paste Production Paste Production From Synodontis Membranaceus Using Different Percentages of Ginger (Zingiber officinale)

Abstract: Synodontis membranaceus was subjected to fermentation (34 +-3 o C) for a period of 4-weeks (one month) with varying concentrations of ginger (5%, 10%, 15%, 20%) and 20% salt as spices to produce paste. The samples were analyzed for proximate composition, pH, microbial load and organoleptic properties at the beginning and end of the fermentation. Results showed steady increase in nutrients such as crude fat, ash, and NFE (nitrogen free extract) but decrease in crude fibre. There were fluctuations in the crude protein of the fermented fish samples. There was an increase in the microbial load of the fermented fish and a slight decrease in the moisture content. The organoleptic test showed preference for taste, aroma, and overall acceptability for fish fermented with 20% ginger

Mechanical property prediction of SPS processed GNP/PLA polymer nanocomposite using artificial neural network

The quality and performance of composite-based materials are functions of their mechanical properties. Hence, a scientific basis is needed for the determination of the feasible combination of process parameters that will bring about excellent mechanical properties. This study examines the potential of artificial neural network (ANN) for the prediction of mechanical properties, namely density and hardness of graphene nanoplatelet (GNP)/polylactic acid (PLA) nanocomposite developed under various operating conditions of spark plasma sintering (SPS) technique. A back-propagation having a 2-12-2 architecture and Levenberg–Marquardt algorithm was developed to predict the mechanical performance in terms of density and hardness property of GNP/PLA nanocomposites. The predictions of the modelled results were compared with those of the experimental value obtained. The model gave a low root-mean-squared error and performed well with the correlation coefficient (R) for both outputs; density (0.95497) and hardness (0.9832) found to be close to 1. The results of the predicted data were discovered to be very consistent with the values obtained from the actual experimental test result. Thus, our study confirmed the efficiency of a well-trained ANN system in estimating the density and hardness property of SPSed GNP/PLA nanocomposites. Hence, the ANN technique is a reliable decision-making tool capable of reducing the excessive cost incurred in experimental characterisation for newly developed polymer composites. This will serve as a decision-making tool for manufacturing industries where SPS techniques will be employed for processing GNP/PLA polymer nanocomposite