The rate at which feedstock is added to the anaerobic digester (AD) reactor has to be adjusted for the growth rate of methanogens bacteria. Increase in biogas yield is as a result of improved mathanogens forming bacteria. Under loading and over loading of feedstock in the AD reactor has effect on methanogens forming bacteria. If more feedstock is added than the bacteria are able to degrade, the process will become acidic. Feedstock has to been fed to the reactor at a uniform rate and volume. If feeding pattern has to change, this must be done gradually so that bacteria can adapt to the new conditions. For optimum biogas yield, required amount of feedstock must be added to the AD reactor. The aim of this research work is to determine the effect of organic loading rate (OLR) on biogas yield from food waste, water hyacinth, cow dung, waste water from abattoir, poultry dropping and pig dung. The experimental set up comprises of single stage and three-stage continuous AD reactors. The same quantity and composition of feedstock were used and this was subjected to a variation of OLR 0.5 kg/m3(1.5 kg/m3, 2 kg/m3, 2.5 kg/m3, and 3 kg/m3). The experiment was conducted within a mesophilic temperature range of 36°C-37°C, percentage total solid (%TS) of 9.98% and percentage volatile solid (%VS) of 78%. pH meter was used to monitored the daily pH reading of the slurry. It was observed that the quantity of biogas yield from the feedstock increases with increasing organic load rate to the optimum value of 1.5 kg/m3and started decreasing above the optimum value for a single stage AD reactor but this was not the case for the three-stages continuous AD reactors that experienced continuous increase in biogas yield with a successive increase in OLR from 1-5 kg/m3-3.0 kg/m3.

In this study, three mediatorless chamber microbial fuel cells were built and experiments were carried out using a mixture of cow dung and water. The volume of the mixture in each cell was 5309440mm 3 and the ratio of the surface area of aluminum anode electrode to graphite rod cathode electrode was 2:1. The maximum open circuit voltage and current obtained was 0.73V and 10.87mA respectively. Maximum total voltage and current obtained for the period of 28 days under investigation was 14.4V and 168.1mA. The average total voltage and voltage drop during the period under investigation were 14.59V and 0.4V respectively. The average power rating per day produced from the each cell was 143.47mAH. This study has shown that cow dung is a potential substrate for energy generation using a single chamber Microbial Fuel Cell (MFC).

The purpose of this paper is to design a 10 million litre capacity petroleum storage tank for use in the oil industry in Nigeria with a view to overcoming the challenges associated with the loss of product due to evaporation. The tank having diameter and height of 27.4m and 17.5m respectively was designed to have two relief valves; a primary valve which would ensure that the product vapour pressure within high-level (h2) in meters of the storage tank does not exceed the minimum acceptable pressure. The second relief valve is designed to relief due to a sudden increase in pressure as a result of a possible fire in the tank. To this end, the design made reference to the American Petroleum Institute Manual 650 (12th Edition) as a guide. Some fundamental considerations include tank shape, height, diameter and materials used. A corrosion allowance of 3mm was also considered.

Inappropriate disposal of Produced Water is one of the causes of degradation of the environment in the Niger-Delta. The effect on farmlands and aquatic life has been disastrous and this disposal continues because of lack of treatment equipment or inability to maintain treatment equipment. This work has developed a method for produced water treatment focusing on oil and salt removal. A small scale produced water treatment system was fabricated. The system’s processes were based on thermal energy; thermal phase separation was used for oil removal and humidification-dehumidification was used for salt removal. The water obtained at the various process stages was tested to ascertain the oil content and salinity. Results obtained showed that oil levels in the produced water dropped from 3034.28mg/l to 380.58mg/ after phase separation which is significant but not meeting the Department of Petroleum Resources (DPR) requirement. However, after the humidification – dehumidification process, it was reduced to 4.02mg/l which meets the DPR requirement of 10mg/l. The salinity also reduced from 887.50mg/l to 35mg/l, this meets DPR acceptable limits for land disposal of 600mg/l.

The purpose of this paper is to design a 10 million litre capacity petroleum storage tank for use in the oil industry in Nigeria with a view to overcoming the challenges associated with the loss of product due to evaporation. The tank having diameter and height of 27.4m and 17.5m respectively was designed to have two relief valves; a primary valve which would ensure that the product vapour pressure within high-level (h2) in meters of the storage tank does not exceed the minimum acceptable pressure. The second relief valve is designed to relief due to a sudden increase in pressure as a result of a possible fire in the tank. To this end, the design made reference to the American Petroleum Institute Manual 650 (12th Edition) as a guide. Some fundamental considerations include tank shape, height, diameter and materials used. A corrosion allowance of 3mm was also considered.