發電機引擎使用廢食用油生質柴油排氣FPM2.5、CPM與PM上水溶性離子及金屬特性

FPM2.5, CPM, and PM-bound water-soluble ions and metals emitted from a diesel engine generator fueled with WCO-biodiesels

許智明(Xu Zhi-Ming)

指導教授 ： 李嘉塗 ； 陳瑞仁

國立屏東科技大學/工學院/環境工程與科學系所/碩士(2020年)

https://doi.org/10.6346/NPUST202000232

摘要

至今，以生質柴油為替代燃料之研究大多著重於柴油引擎尾氣中可過濾性total-PM(Total Filterable Particulate Matter, TFPM)，而有關排氣中可過濾性細微粒(Fine Filterable Particulate Matter，FPM2.5)及凝結性微粒(Condensable Particulate Matter，即CPM)特性之相關研究甚少，此可能導致低估柴油引擎尾氣之健康風險。此外，目前世界各國已有完善且嚴格道路用柴油引擎(如：柴油小客車、重型柴油車…等)尾氣污染物排放標準；而非道路用柴油引擎(如：發電機)之數量雖然較道路用柴油引擎少，然其尾氣至今尚無任何污染排放規範。本研究以石化柴油(D100)中添加20%及40%廢食用油生質柴油(以W20及W40表示)為燃料，進行排氣FPM2.5及CPM採樣，以探討其做為引擎發電機替代燃料時排氣FPM2.5、CPM與PM上水溶性離子及金屬特徵。
研究結果顯示：與D100相較，發電機引擎3.0 kW負載下使用W20及W40時排氣FPM2.5濃度隨生質柴油添加比增加而有明顯遞減(分別減少8.3及10.6 mg/Nm3)；使用W20時排氣有機CPM濃度雖有些微增加(+0.8 mg/Nm3)、然無機CPM濃度則降低較多(–1.44 mg/Nm3)，致其Total-CPM濃度較D100時降低；使用W40時排氣無機CPM及有機CPM濃度均增加，致其Total-CPM濃度較D100時明顯增加。與D100相較，使用W20時排氣總PM濃度有降低(減少17%)，而使用W40時排氣總PM濃度則上升(增加16%)；與D100相較，使用W20及W40時排氣CPM/FPM2.5值均增加，且隨生質柴油添加比提高其比值有增加。與D100相較，使用W20及W40時排氣FPM2.5、無機CPM、有機CPM及總PM上所測水溶性離子總濃度及各PM上水溶性離子含量均有減少，且均隨生質柴油添加比增加而遞減(除W20之無機CPM濃度外)；排氣PM上水溶性離子均主要分佈於無機CPM上(佔82%)、有機CPM(佔13%)次之、FPM2.5上最少(佔5%)。與D100相較，使用W20及W40時排氣FPM2.5、無機CPM及有機CPM上ΣMetals濃度隨生質柴油添加比增加而降低。使用D100、W20及W40各油品時其排氣FPM2.5、無機CPM及有機CPM上金屬大致以Na、Mg、Al、K、Ca、Fe、Zn及Sn為主；排氣PM上金屬均主要分佈於無機CPM上(佔54.5%)、有機CPM(佔25.9%)次之、FPM2.5上最少(佔19.6%)。使用D100、W20及W40時排氣PM上非致癌有毒金屬(Al、Cr及Mn)風險及致癌金屬(Cr及Ni)風險均在可接受範圍。

關鍵字

柴油引擎發電機 ； FPM2.5 ； CPM ； 水溶性離子 ； 金屬

並列摘要

Most of the researches using biodiesel as a diesel alternative have focused on the emissions of total filterable particulate matter (TFPM) from the diesel engines so far. However, little concern has been to investigating the characteristics of filterable fine particulate matter (FPM2.5) and condensable particulate matter (CPM) emission from diesel engines, which might underestimate the health risk of diesel engine exhaust. Additionally, the emission regulations of road diesel engines, such as light-duty diesel vehicles, heavy-duty diesel vehicles etc., have been well established; however, the emissions of nonroad diesel engines (e.g. diesel engine generators), have not been regulated presently, because their amount are less than on-road ones. In the current study, the testing fuels were prepared by adding 20 and 40% of waste cooking oil (WCO) into conventional diesel (D100) to form W20 and W40, respectively. The emission of FPM2.5 and CPM were then collected from a diesel engine generator to analyze the effect on the characteristics of their mass concentrations, soluble ions, and metal contents by using alternative fuels.
Results show that the FPM2.5 concentrations were obviously reduced 8.3 and 10.6 mg/Nm3 when replacing D100 by W20 and W40, respectively, at 3.0 kW operation. The inorganic-CPM emission slightly increased by 0.8 mg/Nm3 when using W20, while that of organic-CPM decreased by 1.44 mg/Nm3. Therefore, the overall CPM (Total-CPM) emission from using W20 was lower than that from using D100. On the other hand, the inorganic- and organic-CPM both increased when W40 was used and caused the significantly higher Total-CPM levels than using D100. The TFPM emission concentrations for using W20 and W40 were reduced by 17% and 16%, respectively, in comparison to using D100. Additionally, the CPM/FPM2.5 increased along with the addition fractions of WCO and it was higher when the engine was fueled with W20 or W40 than with D100. For soluble ions, the ion contents on each and the sum of FPM2.5, inorganic- and organic-CPM, and TFPM decreased with the WCO addition fraction, except the inorganic-CPM by using W20. Specifically, the soluble ions mainly distributed on the inorganic-CPM (82%), followed by organic-CPM (13%), and FPM2.5 (5%). The concentrations of metal components (ΣMetals) on FPM2.5, inorganic-, and organic-CPM, decreased with the WCO addition fraction. The dominant metals of FPM2.5, inorganic-, and organic-CPM were Na, Mg, Al, K, Ca, Fe, Zn, and Sn despite the use of different fuels. The total metal distribution on inorganic-CPM was 54.5%, on organic-CPM 25.9%, and on FPM2.5 19.6%. Fortunately, the excess noncancer risk caused by Al, Cr, and Mn and lifetime cancer risk by Cr and Ni both stayed in the acceptable range on PM for all the tested fuels.

並列關鍵字

diesel engine generator ； FPM2.5 ； CPM ； water-soluble ions ； metals

參考文獻

Abdul, K.S.M., Jayasinghe, S.S., Chandana, E.P., Jayasumana, C., De Silva, P.M.C., 2015. "Arsenic and human health effects: A review." Environmental Toxicology and Pharmacology, Vol. 40, No.3, pp. 828-846.

Amiri, M., Sadighzadeh, A., Falamaki, C., 2016. "Experimental parametric study of frequency and sound pressure level on the acoustic coagulation and precipitation of PM2. 5 aerosols." Aerosol and Air Quality Research, Vol. 16, pp. 3012-3025.

Atmanli, A., 2016. "Comparative analyses of diesel–waste oil biodiesel and propanol, n-butanol or 1-pentanol blends in a diesel engine." Fuel, Vol. 176, pp. 209-215.

Agarwal, A. K., and Das, L. M., 2000, "Biodiesel development and characterization for use as a fuel in compression ignition engines." Journal of Engineering for Gas Turbines and Power, Vol. 123, pp. 440-447.

Agency for Toxic Substances and Disease Registry (ATSDR)., 2004a. Toxicological Profile for Copper.