Reduction of Harmful Emissions from Domestic Power Generator Usage in Nigeria - A Tribological Approach

Abstract

Worldwide concern for the release of harmful emission from Internal Combustion (IC) engines requires the optimization of the quantity of fuel used, types of fuel blend used and type of lubrication utilized. In Nigeria, the electrical power requirements of many households rely more on alternative sources such as Solar systems and fossil fuel-powered generators. The use of these generators is known to produce exhaust fumes that are harmful to humans and the environment. This study investigated the effect of using two different commercially available lubricating oils for gasoline-fueled power generators for domestic applications in comparison to used oils. These are SAE 40 and SAE 20W50. The effect of Boron additive on the two oil brands and used oils (or aged oils) at different speeds on emission from the exhaust stream from the generator was investigated. This is to provide a better understanding of the behavior of Boron additive with SAE 40, SAE 20W50, and aged oils. The study also compared results of torque and emission measurements from oils containing boron to oils without the Boron additives at different speeds. The instruments used to carry out the measurement are a digital tachometer, torque meter (contact type), and 5-gas exhaust analyzer. Results from this study indicated a general decrease in torque with increased speed for all the lubricating oils. This is in agreement with the results of similar studies on torque outputs from IC engines with increasing speeds. However, oils lubricated with Boron additives minimized this loss at a different speed more in SAE 20W50, SAE 40 than in used oils. Carbon monoxide emission from these results indicated that generators lubricated by aged oils are highest at all speed ranges irrespective of Boron additive inclusion. Cleanliness from a gasoline-powered generator is possible if Boron additive is added to lubricating oils. The concentration of NOx emission was found to rise considerably only when operated at the highest speed for aged oils. The results of this study indicated that tribofilms formed by boron-containing oils played a role in preventing torque reduction or power loss and CO emissions from power generators for domestic use. This behavior was attributed to the friction-reducing boric acid and wear resistance borate glass contained within the trilayer. However, tribofilms formed by used oils on tribological parts of the engine gave poor torque reduction results in comparison to that provided by fresh oils. This indicated that when lubricating oils in power generators used in homes are aged beyond the recommended interval for replacement, substantial power loss and harmful emissions are released to the surroundings.