Reduction of pollutant emissions and promotion of energy efficiencies on diesel engines fueled with biodiesel and emulsified diesel

• Main Authors: Yuan-Chung Lin, 林淵淙
• Other Authors: Wen-Jhy Lee
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/05819667768453885676

博士 === 國立成功大學 === 環境工程學系碩博士班 === 94 === The recent energy crisis caused the cost of fuel to rise dramatically. Thus, some people have used fishing boat fuel oil (FBFO) instead of premium diesel fuel (PDF) because of the price difference between FBFO and PDF, despite the increased risk of environmental pollution. Light cycle oil (LCO) can be added to PDF to reduce the consumption of diesel, but the sulfur and aromatic content in LCO are higher than those of PDF. The fraction of LCO being added in the PDF should be strictly regulated due to the maximum allowed sulfur (0.035wt%) and total aromatic contents (35wt%) in diesel fuel in Taiwan. A proper alternative energy source can slow down the impact of the energy crisis and alternative fuels such as biodiesel are being considered in many countries owing to increased environmental awareness and the rising price of diesel. Developing alternative diesel fuels is driven by the necessity to reduce the environmental impact of emissions without modifying engines. Biodiesel is produced from animal fats or vegetable oils with methanol or ethanol as the catalyst by transesterification reaction. Using biodiesel instead of diesel reduces fuel consumption. Recently, studies of water-in-oil emulsions in conventional liquid fuel engines have confirmed that the water in emulsified diesel plays an important role in the combustion process. Water emulsification has a potential to slightly improve the brake efficiency and to significantly reduce the formation of thermal NO, soot, hydrocarbons and PM in diesel engines with no worsening of specific fuel consumption. Besides, emulsified diesel also reduces the heat flux, the metal temperatures, thermal loading and the wear-metal debris in the crankcase oil of emulsified diesel. The characteristics of polycyclic aromatic hydrocarbons (PAHs) in the exhaust of diesel engines fueled with fishing boat fuel oil, light cycle oil, palmbiodiesel, paraffinic biodiesel and emulsified diesel were investigated. PAHs samples including both gas- and particle-phases were collected and twenty one individual PAHs were analyzed primarily by a gas chromatography/mass spectrometer (GC/MS). The objective of this study is to set up the data bank for the calculation of total amount of PAHs emission, the PAHs dispersion modeling and the assessment of PAHs control. The major conclusions of this study are as follows : 1.TDVs (traveling diesel vehicles) illegally using FBFO had a significant impact on the total amounts of PAHs emissions from mobile sources and hence deserve more attention. 2.If the maximum percentage of LCO being added to PDF was 3.5% in Taiwan, it would result in an 80.4 % and a 201 % increase in emissions of total PAHs and total BaPeq, respectively. These results strongly suggest that LCO used in traveling diesel vehicles significantly influences PAHs emissions. Therefore, the fraction of LCO being added in the PDF should be strictly regulated. 3. Palm-biodiesel is such an oxygenated fuel that can improve combustion efficiency in diesel engines, but adding more than 50% palm-biodiesel fraction to premium diesel fuel causes incomplete combustion in the diesel-engine generator and impedes the release of energy from the fuel. The modification of diesel engines is needed for high fraction of biodiesel blends in the future. 4.There was no significant difference in unusual operations and damage from deposits inside the chamber or in the inferior condition of the engine oil after 300 hrs (18,000 km) operation of engines by using palmbiodiesel-PDF blends or paraffinic-palmbiodiesel blends instead of PDF fueled on HDDEs. 5.Emulsified diesel and bio-solution did decrease PAHs, PM and SOF emissions from the exhaust of diesel generators and improve combustion efficiency and save energy effectively via adding bio-solution. With the increasing price of diesel, emulsified diesel containing NOE-7F has the potential for commercial application.