直接噴射柴油引擎使用生質柴油之多環芳香族化合物排放特性研究

The Emissions of Polycyclic Aromatic Hydrocarbons from a Direct Injection Diesel Engine Using Biodiesel

徐正(Cheng Hsu)

指導教授 ： 吳中興

國立臺灣大學/生物資源暨農學院/生物產業機電工程學研究所/碩士(2005年)

https://doi.org/10.6342/NTU.2005.10294

摘要

移動污染源一直是製造空氣污染的主要來源，而柴油引擎更是其大宗，本論文探討直接噴射柴油引擎在使用超級柴油與純生質柴油兩種燃料在各種操作條件下所排放廢氣，並對其加以收集、萃取、分析，以了解廢氣中多環芳香族碳氫化合物（PAHs）的種類和濃度。量測結果顯示在使用超級柴油全負載時柴油引擎在扭力最大時所排放之PAHs總重量濃度最高；結果也指出在低轉速時則以低苯環數PAHs為主；而在高轉速時，致突變性和致癌性之PAHs化合物排放量和毒性最強的BaP則有增多的趨勢。在排放個別PAHs成份中，其Phe濃度值明顯比其他成份高出很多；在其他成份中，通常以Nap、Pyr的濃度較高。
在改用生質柴油全負載時柴油引擎也在扭力最大時所排放之PAHs總重量濃度最高，而在各種類的比較上，結果指出在使用生質柴油後，致癌性化合物有明顯的減少，而揮發性化合物則減少較少。在排放個別PAHs成份中，其Nap濃度值明顯比其他成份高出很多；在其他成份中，通常以Phe、Pyr、BaP濃度較高。我們同時也發現致癌性化合物不論使用超級柴油或是生質柴油都會隨著轉速的提高，而呈現增加的趨勢。
而隨著馬力的增大、油耗的增加、排氣溫度的上升，則會致使致癌性化合物大量的生成。使用生質柴油後，可比使用超級柴油減少約30%~40%的PAHs總排放量，而致癌性PAHs則減少約30﹪~50﹪，這也印證生質柴油的確能有效的減低PAHs的排放。

關鍵字

柴油引擎 ； 超級柴油 ； 生質柴油 ； PAHs

並列摘要

Nowadays mobile source was always the major cause of air pollution producing, diesel engine especially. In this work, a direct injection diesel engine using different fuels, low sulfur diesel and pure biodiesel, was operated under different conditions and the emission which contained different types and different concentrations of polycyclic aromatic hydrocarbons (PAHs) was collected, extracted and analyzed. The result showed that at the 100% throttle, the maximum PAHs emission diesel occurs when engine is operated at the maximum torque,and using the low sulfur diesel. It also showed that the majority of exhaust is low molecular weight PAHs when the engine was at low speed range operation.The exhaust of mutation and carcinogen PAHs compounds and the most toxic BaP have the trend of increasing on high rotating speed. Apparently the concentration of Phe was higher than other compounds in emission and Nap and Pyr were usually in the majority in the remained compounds.
When biodiesel was used, the result revealed that maximum torque of diesel engine was operated at full load exhausted the maximum mass concentration of PAHs. The result showed that after biodiesel was used, the concentration of carcinogens would decrease obviously, and the amount of PAHs also decreased, but less than the former. Apparently the concentration of Nap in PAHs emission is higher than other compounds, but the major compositions in other components are Phe, Pyr and Bap. These result showed that whether low sulfur diesel or biodiesel were used, the increasing tendency of the concentration of carcinogen PAHs would increase with the engine speed.
With the increasing horsepower, oil consumption and emission temperature would cause the gradual generation of carcinogens. After biodiesel was used, 30 to 40% decrease of the total PAHs emissions, and 30 to 50% decrease of carcinogens PAHs than these when the low sulfur diesel was used, this also indicates that PAHs emission can be effectively reduced by using biodiesel.

並列關鍵字

Diesel engine ； low sulfur diesel ； biodiesel ； PAHs

參考文獻

1. Abbass, M. K., 1987, “The Aging of Lubricating Oil, The Influence of Unburnt Fuel and Particulate SOF Contamination”, SAE, 87285.

2. Abbass, M. K., 1991, “ The Survivability of Diesel Fuel Components in the Organic Fraction Particulate Emission from an IDI Diesel”, SAE, No. 910487.

3. Abdul Monyem, Jon H.Van Gerpen., 2001, “The Effect of Biodiesel Oxidation on Performances and Emission”,Biomass and Bioenergy,Vol.20

4. AL-Widyan, M.I., Tashtoush,G.,Abu-Qudais,M., 2002, “Utilization of Ethyl ester of Waste Vegetable Oils as Fuel in Diesel Engines”, Fuel Processing Technology, 76, pp.91-103.

5. Bagley,S.T., Gratz,L.D., Johnson,J.H.,McDonald,J.F., 1998, “Effect of an Oxidation Catalytic Converter and a Biodiesel Fuel on the Chemical, Multagenic, and Particle Size Characteristics of Emission from a Diesel Engine”, Environmental Science and Technology,32, pp.1183-191.