本研究為探討台灣地區行駛中四行程機車實車使用酒精汽油之適用情況，針對不同比例乙醇，分別以未添加及添加10％及30％體積比於台灣現有兩公司(T公司、F公司)市售九五無鉛汽油中(E10、E30)做為基本實驗用燃料。以四行程機車，在不同行駛速度：怠速惰轉、30及50km/hr操作條件下，針對每種燃料油之引擎排放傳統性污染物CO、HC及CO2進行採樣分析。
研究結果顯示，所有未添加酒精之市售汽油機車引擎於怠速惰轉條件下所排放之CO、HC及CO2之濃度均高於混摻10％及30％乙醇之油品所排放之污染物濃度。實驗結果中未混摻之T95-E0及F95-E0所排放CO平均濃度為2.44、3.82％，較市售九五無鉛汽油混摻10％乙醇所排放CO平均濃度為1.15％（T95-E10）、1.84％（F95-E10）及混摻30％乙醇所排放CO平均濃度為0.35％（T95-E30）、0.78％（F95-E30）平均濃度為高。顯示混摻乙醇之無鉛汽油可獲得較佳之污染減排效果。
比較兩款市售油品添加乙醇在不同行駛速度下研究結果中：顯示行駛速度30km/hr測試條件下CO平均濃度分別為0.12、0.1％；50km/hr測試條件下CO平均濃度皆為0.1％，皆比未混摻之T95-E0及F95-E0所排放CO平均濃度有極大的削減量，以上的結果顯示T公司與F公司於乙醇混摻30％行駛於50km/hr條件下，CO污染排放均有顯著降低的情況。
關鍵字：酒精汽油、怠速、汽油引擎、乙醇 Abstract
This study was aimed to access the generation or depletion of air pollutants including carbon monoxide, hydrocarbons and carbon dioxide emitted from the exhaust of 4-stroke motor engine simulating idling, 30 and 50 km/hr, respectively, cruising speed conditions. The commercial 95-LFG were purchased and obtained from two petroleum companies, CPC and Formosa, in Taiwan. Alcohol, the purity higher than 99.5%, was used as fuel additive blended with two target gasolines in 10, 30% vol. to test in this study.
The results of those data reveal that the emission concentration of CO, HC and CO2 of commercial 95-LFG fuels all are higher than with blending alcohol fuels. Among different blending gasolines, the exhausts of CO average concentration of T95-E30 and F95-E30 (0.35% and 0.78%, respectively) have much lower emission potentials. Adding more alcohol in commercial 95-LFG will increase the combustion efficiency in single spark motor engine.
In compare with the CO concentration emitted from these target fuels blending with cruising speeds. Higher cruising speed, T95-E30 and F95-E30 all will reduce more CO under 50 km/hr than 30 km/hr. However, even adding more alcohol in commercial 95-LFG still have more CO emission potential under idling condition.
Keyword: alcohol, idling, single spark motor engine.
