Recently, the issues regarding the growing consumption of fossil fuel and resource depletion are becoming more serious all over the world. Besides, environmental regulations on exhaust gases from vessels, vehicles, power plants and so on are being tightened more. To save fuel and cope with environmental regulations on exhaust emissions, active studies on eco-friendly fuel development are in progress, but there is a lack of studies on emulsified oil, which mixes water and heavy oil in a marine boiler.
Accordingly, this study experimented the reduction effect of special emulsified oil mixed with an emulsifier at a content ratio of 0%, 5%, 15% and 25% between Bunker-C oil and water when themanufactured oil was applied to the marine boiler. Also, the ingredients of the manufactured emulsified oil and the distribution state of water droplets were analyzed.
According to the result of the experiment measured within the scopeof this study, nitrogen oxide(NOx) and sulfur oxide(SOx) reduced by up to 50.9% and 55.4% respectively. At an average oxygen concentration of 4%, nitrogen oxide(NOx) and sulfur oxide(SOx) reduced by up to 31.41% and 37.47% respectively, which means the manufactured emulsified oil was excellent in reducing exhaust gases.
Oxygen(O 2 ) increased by 4.2% and carbon monoxide(CO) and carbon dioxide(CO 2 ) decreased by up to 63.8% and 2.1% respectively. The temperature of exhaust gases decreased by up to 14.3% and combustion loss ratio was less than nearly 0.03, but combustion performance was relatively good, compared to the moisture content.
When the water droplet distribution state of the manufactured emulsified oil was analyzed, it was revealed that water and fuel oil were evenly emulsified at a mean diameter of around 2μm.
The marine boiler used in this study is a fixed type in which proportional control of supplied air is impossible according to complete combustion conditions.
In conclusion, it s anticipated that if emulsified oil applies to a rotary-type boiler that allows proportional control according to optimum combustion conditions, a greater reduction effect could be obtained.