Papers by Author: S.J. Ojolo

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: In this work, a comparative study of biogas production from poultry droppings, cattle dung, kitchen waste, fruit waste and vegetable waste was done under the same operating conditions. 3kg of each waste was mixed with 9kg of water and loaded into the 5 constructed digesters. Biogas production was measured using water displacement method for a period of 40 days and at an average temperature of 30.5oC. Results indicated that poultry droppings produced 0.0332dm3/day, cow dung produced 0.0238dm3/day, Kitchen waste produced 0.0080dm3/day, vegetable waste produced 0.0066dm3/day and fruit waste with 0.0022dm3/day. It is concluded that poultry droppings produced more biogas because it contains more nutrients and nitrogen compared with plant and other animal waste