本研究以一部符合國內三期法規標準,後端防制設備為氧化觸媒之全新重型柴油引擎,使用不同比例之生質柴油探討尾氣排放之揮發性有機物組成特徵與排放係數。實驗分兩部份,第一部分使用傳統純石化柴油 (D100) 和五種不同比例之生質柴油,包含添加比例為20% (B20)、40% (B40)、60% (B60)、80% (B80) 與100% (B100) 之油品,探討使用柴油及不同比例之生質柴油之VOCs排放特性;第二部份則以添加5% (B5) 之生質柴油進行1000 hr之引擎耐久測試,探討引擎耐久測試VOCs排放狀況。本研究將引擎架設於動力計上以美國暫態循環測試 (US Transient Cycle) 進行污染排放測試,以不鏽鋼採樣桶 (Canister) 採樣並以氣相層析質譜儀 (Gas Chromatograph / Mass Spectrometer, GC/MS)進行VOCs分析。研究結果顯示引擎使用生質柴油與D100相較,對排放CO及NOx平均皆有些微增量趨勢,THC與PM則有減量成效,TVOCs部分為皆有減量趨勢,其中以B40減量效果最佳,依排放係數大至小依序為D100 > B20 > B80 > B100 > B60 > B40,而使用生質柴油對排放VOCs族群之Aromatics及Carbonyls皆有減量成效,各族群依係數大小順序為Aromatics > Carbonyls > Alkanes > Alkenes > Others。在耐久測試方面,CO、THC、PM及TVOCs皆不會因為行駛時數之累積而產生劣化增加污染排放,而尾氣排放前三種主要化合物為Acetone、Acrolein及Benzene,耐久時數的累積對引擎排放VOCs族群比例亦無顯著影響。此外,柴油引擎在冷啟動時較熱啟動有更高的法定污染物及TVOCs排放係數。
In this study, VOCs (Volatile Organic Compounds) emissions from a heavy-duty diesel engine were measured by using biodiesels with various blending percentages. Pure diesel (D100) and 5 biodiesels with 20% (B20), 40% (B40), 60% (B60), 80% (B80) and 100% (B100) blending percentages are used as fuel to compare the emission characteristics. In addition, B5 (5% blending) is used for 1000 hr durability test. The diesel engine was installed on a dynamometer and US Transient Cycle test was performed for the emission measurement. VOCs samples were collected by canisters and were analyzed by GC/MS (Gas Chromatograph / Mass Spectrometer). The results show that using biodiesel can reduce THC, PM and TVOCs emissions, but CO and NOx are increased in comparison with D100. TVOCs emission is reduced by using biodiesel and B40 has the highest reduction rate. The emission factors from highest to lowest are D100 > B20 > B80 > B100 > B60 > B40. Aromatics and Carbonyls are also reduced by using biodiesel. The emission factors from highest to lowest in sequence by VOCs''s groups are Aromatics > Carbonyls > Alkanes > Alkenes > Others. The result of durability test show that the emissions of TVOCs, CO, THC, PM and VOCs would not increase after long term driving. In addition, the criteria air pollutants and VOCs emissions are higher for cold star test than hot start test.