Papers by Author: A.O. Adelaja

Abstract: The study of internal chemical processes involving nitrogenous species forms an important part in the understanding of parameters which lower NO_x emission from combustion systems. The focus of this research is to numerically model the prediction of formation of pollutant emission in a continuous internal combustion engine (ICE), from finite rate chemical equilibrium equations. The main source of nitrogen in the chemical formation of NO_x is atmospheric, and a very small portion is caused by nitrogen compounds found in some fuels. A mathematical modeling was carried out with these equations using MATLAB simulation to predict the concentration of Nitric Oxide NO; a pollutant, at different flame temperatures and reaction timing of ICE. The temperatures under consideration vary from 1500K to 2300K. The concentration of the pollutant was evaluated by the analytical and numerical methods for a spark ignition engine at a temperature of 2000K; pressure of 1atm, considering a sample containing 78% of Nitrogen and 4% of Oxygen and 78% Nitrogen and 21% Oxygen held between zero to one second in the course of the combustion process, while the computer programme simulated between zero and 100seconds. The concentrations predicted were found to increase as the flame temperature, the combustion time increase as depicted on the results and as the percentage composition of Oxygen in the mixture increases, but reduces with increasing fuel nitrogen content.

Abstract: Most of the attempts made at designing shell and tube heat exchangers have been limited to thermal hydraulic design. This study however, considers both the thermal and mechanical design of the E-type shell and tube heat exchanger with the aid of computer programming. It involves developing a simple user-friendly computer programme for the heat transfer calculations and ensures that the computational time is kept minimal. The algorithm is designed such that after the conditions for the thermal analysis are satisfied, the programme automatically proceeds to the mechanical design. The programme written in Visual Basic was tested using a model and the simulated result presented.

Abstract: The need for renewable and environmentally friendlier energy sources has led to intensified efforts with respect to research in that area. One of such endeavours is the production of biofuels from various sources of vegetable oils. Therefore, this work is aimed at producing biodiesel from freshly prepared and clean palm kernel oil and groundnut oil making use of methanol and sodium hydroxide pellets in a base-catalysed trans-esterification reaction. 185g groundnut oil and 187g palm kernel was trans-esterified with 37g of methanol and 0.7g of NaOH pellets at 55°C operating temperature. The result gave a percentage conversion of 91.98% for groundnut oil feedstock and 16.18g of glycerol (i.e. soap) as bye product, while palm kernel oil feedstock gave a yield of 90.53% conversion and 15.20g of glycerol. The biodiesel retained the physical properties of the oil such as smell and colour. The density of the biodiesel from groundnut oil was found to be 850.80kg/m³ while that of palm kernel oil gave 848.0kg/m³. The kinematic and dynamic viscosities of groundnut oil bio-diesel were obtained to be 15.9mm²/s and 13.5 x 10^-3kgm^-1s^-1 while that of palm kernel gave 7.65mm²/s and 6.49 x 10^-3kgm^-1s^-1 respectively.

Abstract: The photovoltaic (pv) forced convection solar dryer comprises the solar collector, dryer and pv assemblies. It is designed for a continuous operation throughout the day. The direct solar irradiation is utilized during sunshine hours and it automatically switches power supply to the battery during cloud covers and non-insolation periods. The inclusion of a heat reservoir enables heat transfer to continue during this period. In this study, thermal and dryer analyses were done. Experimental investigations were carried out to evaluate the performance of the system by drying plantain chips. The useful power collected was found to be, 391.50W, collector efficiency, 65.6%, dryer efficiency, 39.6%, average drying rate during insolation, 0.0169kg/hr and total drying time was 23 hours. The maximum temperature attained was 55oC. The average drying non insolation period was 0.0112kg/hr. The capital cost is less than $350.

Abstract: This solar conversion system incorporates a suction fan powered by a solar PV module. Located at the outlet of the chamber is the d.c suction fan utilised to achieve forced air circulation without the use of external power supply like grid electricity, fossil fuel and battery. Simple thermal energy balance equations and heat transfer equations were employed in the design of the system. The operational efficiency of the collector is 83.2% and mass flow rate 1.58kg/min, the maximum temperature achieved in the chamber was 58oC. The system was used to dry vegetable, hydrophylum. The capital cost is less than $150.