農用輕型四行程引擎使用添加乙醇及正丁醇92無鉛汽油排氣粒狀物特性

Characteristics of particulate matter emitted from an agricultural four-stroke light-duty petrol engine fueled with 92 unleaded gasoline with ethanol and n-butanol additives

李承學(LI CHENG-HSUEH)

指導教授 ： 蔡仁雄 ； 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(2022年)

https://doi.org/10.6346/NPUST202200175

摘要

有關農用引擎動力設備(Agricultural Engine Powered Machines，簡稱AEPMs)排放空氣污染物對操作者健康之影響值得加以重視，然有關AEPMs排氣之研究至今仍少。為釐清AEPMs排氣污染物特性，本研究以國內農用機械數量最多之動力噴霧機(HONDA GX50)為試驗對象，於7000 rpm最大輸出功率1.5 kW負載下使用100% 92無鉛汽油(以G100表示)、90% 92無鉛汽油+10%乙醇(以Et10表示)、80% 92無鉛汽油+20%乙醇(以Et20表示)、90% 92無鉛汽油+10%正丁醇(以Bu10表示)及80% 92無鉛汽油+20%正丁醇(以Bu20表示)等五種混合燃料，探討其排氣總粒狀物(Total Particulate Matter，簡稱TPM)及其粒狀物(Particulate Matter，簡稱PM)上元素碳(Elemental Carbon，簡稱EC)、有機碳(Organic Carbon，簡稱OC)、水溶性離子及金屬等成分特性。
研究結果顯示：噴霧機7000 rpm操作下使用G100、Et10、Et20、Bu10及Bu20時，其排氣TPM濃度由高至低依序為G100 > Bu10 > Et10 > Bu20 > Et20，且會隨乙醇及正丁醇添加比提高而下降。與G100相較，噴霧機引擎使用Et10、Et20、Bu10及Bu20時，其排氣TPM濃度依序可削減15.3、39.7、11.4及23.4%。無論使用何種油品，噴霧機引擎排氣TPM濃度約有六成是由TC所貢獻，OC/EC值之平均為1.14±0.28。與G100相較，噴霧機引擎使用Et20時對排氣TPM上TC、OC及EC有最佳減量效果(分別可削減51.0、51.0及51.0%)，而使用Bu20時次之(分別可削減36.1、30.3及42.0%)。排氣TPM上ΣIons濃度由高至低依序為G100 > Bu10 > Et10 > Bu20 > Et20；而排氣TPM上ΣIons含量由高至低依序為Bu20 (7.69%) > Et10 (7.58%) > Bu10 (7.24%) > G100 (7.12%) > Et20 (6.94%)，排氣TPM mass約有7.3%是由水溶性離子所貢獻。無論使用何種油品，TPM上水溶性離子大致上以Na+、NH4+、Cl-及NO3-等4離子為主。與G100相較，使用Et10及Et20時排氣TPM上ΣIons濃度之削減率分別為21及37%，而使用Bu10及Bu20時其削減率則分別為15及25%。然使用使用乙醇及正丁醇添加之混合汽油時，其排氣TPM上ΣIons含量皆隨添加比提高而增加。排氣TPMs上ΣMetals濃度由高至低依序為Bu10 > Bu20 > G100 > Et20 > Et10；而排氣TPM上ΣMetals含量由大至小依序為Et20(28.4%) > Bu20(28.2%) > Bu10(22.1%) > G100(18.2%) > Et10(13.2%)，排氣TPM濃度約有22%是由金屬所貢獻。無論使用何種油品，噴霧機排氣TPM中均以Na、Mg、Al、K、Ca、Fe及Zn等金屬為主要貢獻物種；而ΣMetals中Major metal、Submajor metal及Minor metal Fraction之平均值依序分別為96.7、3.13及0.49%。與G100相較，使用Et10及Et20時引擎排氣TPM上ΣMetals排放均有降低，且隨乙醇添加比例提昇(10%→20%)，引擎排氣TPM上ΣMetals排放量有隨之增加的現象；而使用Bu10及Bu20時，引擎排氣TPM上ΣMetals排放則略有增加，且隨正丁醇添加比的提昇其排氣ΣMetals排放稍有增加。

關鍵字

四行程引擎 ； 乙醇 ； 正丁醇 ； 排氣總粒狀物 ； 碳成分 ； 金屬

並列摘要

The impact of air pollutants emitted by agricultural engine powered machines (AEPMs) on the operator health is clearly worth considering. However, there have been few studies focusing on the exhaust of AEPMs. In order to specialize the pollutant characteristics in AEPMs’ exhaust, this study tested a power sprayer (HONDA GX50), which stood for the largest number of agricultural machinery in Taiwan. We also tested five gasoline-ethanol (Et)/butanol (Bu) blends, including the pure 92-octane-unleaded gasoline (G100), Et10, Et20, Bu10 and Bu20 (number: the additive fraction in gasoline blend) used for the engine operation at 7000 rpm with the maximum output power (1.5 kW). Furthermore, the total particulate matter (TPM) and their elemental carbon (EC), organic carbon (OC), water-soluble ions and metal contents were measured.

The magnitude of TPM concentrations emitted from the sprayer was in the order G100 > Bu10 > Et10 > Bu20 > Et20, indicating a negative relationship between the TPM level and Et/Bu additions. Using Et10, Et20, Bu10, and Bu20, could reduce TPM emissions by 15.3%, 39.7%, 11.4% and 23.4%, respectively, from using G100. About 60% of the TPM concentration in the sprayer engine exhaust was contributed by TC (average OC/EC = 1.14±0.28) by using various fuels. The sprayer engine using Et20 had the most and the same reduction of TC, OC and EC in TPM (51.0%) from using G100. Additionally, the second place was taken by using Bu20, which reduce 36.1% TC, 30.3% OC, and 42.0% EC. The ΣIon concentrations on TPM for the tested fuels followed the order G100 > Bu10 > Et10 > Bu20 > Et20; while this order was Bu20 (7.69%) > Et10 (7.58%) > Bu10 (7.24%) > G100 (7.12%) > Et20 (6.94%) for the mass contributions of ΣIons on TPM. About 7.3% of TPM mass was contributed by the water-soluble ions. The water-soluble ions on TPM were dominated by Na+, NH4+, Cl- and NO3-, regardless of the difference in fuel composition. Compared with G100, the reduction rates of ΣIons concentration in TPM were 21%, 37%, 15% and 25% by using Et10, Et20, Bu10 and Bu20, respectively. However, the contributions of ΣIons to the TPM increased with an increasing addition of ethanol or butanol. The concentrations of ΣMetals in TPMs for the tested fuels followed the order Bu10 > Bu20 > G100 > Et20 > Et10, while the order was Et20 (28.4%) > Bu20 (28.2%) > Bu10 (22.1%) > G100 (18.2%) > Et10 (13.2%) for the ΣMetals contributions to the TPM mass. About 22% of TPM concentration was contributed by metals. The main TPM containing metals were Na, Mg, Al, K, Ca, Fe and Zn, for all the tested fuels. The averages of major, sub-major and minor metal fractions in theΣMetals were 96.7%, 3.13% and 0.49%, respectively. Using Et10 and Et20 blends reduced the emission of ΣMetals in TPM from using G100, while the ΣMetals levels increased with the increase of ethanol addition (from 10% to 20%). On the other hand, the uses of Bu10 and Bu20 slightly increased the ΣMetals emissions in TPM. The ΣMetals levels increased with an increasing ratio of n-butanol additive.

並列關鍵字

four-stroke engine ； ethanol, n-butanol ； n-butanol ； total particulate matter in the exhaust ； carbonaceous content ； metal content

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