應用AERMOD模式評估都會區車輛使用酒精汽油之有害空氣污染物影響

Characterize Air Toxics Impacts from Ethanol-blended Gasoline Vehicles in Urban Area by AERMOD Modeling

蔡欣汝(Hsin-Ru Tsai) ； 蔡俊鴻(Jiun-Horng Tsai)

《燃燒季刊》 102期 (2018/08) Pp. 14-26

https://doi.org/10.30041/CQ.201808_(102).0003

摘要

本篇文章乃應用空氣擴散模式探討於都會區使用酒精混和汽油對有害空氣污染物環境濃度之可能影響。研究以苯及甲醛為評估物種；討論車種包括汽油小客車、營業小客車、汽油小貨車、二行程及四行程機車等汽油車；測試油品為乙醇含量15 vol%之酒精混合汽油（E15）與市售（95無鉛汽油）等二種。應用MOBILE排放模式及本土化參數推估選定車種之有害空氣污染物排放係數，再利用AERMOD模式模擬研究區域環境大氣有害空氣污染物濃度。共有四個模擬情境，包括基準情境（使用市售油）及三個控制情境（不同比例車輛使用E15油品），以探討不同策略下對環境大氣有害空氣污染物濃度之影響程度。排放推估結果顯示，汽油車使用E15為燃油時較使用95無鉛汽油有較低之苯及甲醛排放，機車使用E15為燃油所致之苯及甲醛排放較汽油小客車或汽油小貨車為低。AERMOD模擬結果顯示，管制情境對都會區市中心之有害空氣污染物濃度有最大改善，與基準情境比較，三種控制情境所致市區環境苯年平均濃度分別降低57%、3%及6%；甲醛年平均濃度則於控制情境一及三分別降低46%、4.6%，控制情境二則些微增加0.28%。整體而言，汽油車使用酒精混和汽油可降低尾氣排放所致之苯及甲醛濃度，特別是機車使用E15酒精汽油，同時反應至都會區環境有害空氣污染物年平均濃度改善。

關鍵字

汽油車 ； 酒精混和汽油 ； 有害空氣污染物 ； 空氣擴散模式

並列摘要

The possibility of using ethanol-blended gasoline as fuel for vehicles and air quality management tools has increased in several counties. This study investigated the potential impact on ambient air concentration caused by organic air toxics from gasoline vehicles while using ethanol-blended gasoline as fuel in an urban area in Taiwan. Two test fuels were used in this study, one ethanol-gasoline blend, containing 15% ethanol by volume (E15), and the other one is commercial unleaded gasoline (G95). Emission factors of air toxics from gasoline vehicles, including passenger cars and motorcycles, were estimated by MOBILE model and local parameter input. The ambient air concentration of organic air toxics was simulated by AERMOD model in the urban area. A total of four scenarios have been conducted in this study including one base case and three E15 cases. Two carcinogenic air toxics are as target pollutants, benzene and formaldehyde, to show the ambient air concentration on those four scenarios, respectively. Emission estimation shows a clear tendency of decreasing organic air toxics from on-road mobile sources while applying E15 instead of G95. Applying ethanol gasoline on motorcycle shows a lower emission of two air toxics than those in passenger cars. Simulation results from AERMOD showed that the great improvement of airborne organic air toxics was found in the down town area. Annual average concentrations of benzene at hot spot area could reduce 57%, 3%, and 6%, respectively, for Case 1, Case 2, and Case 3, compared with those of the base case (all vehicles use commercial gasoline (G95) as fuel). For formaldehyde, the variance of annual average concentrations at hot spot area are -46%, 0.28%, and -4.6%, respectively, for Case 1, Case 2, and Case 3, compared with those of the base case. The results indicate that introducing ethanol-gasoline blend into an urban area for instead of commercial gasoline, especially the case of E15 for motorcycle, could reduce the emission of benzene and formaldehyde as well as to improve ambient air concentration in down town area.

並列關鍵字

Gasoline vehicles ； ethanol-blended gasoline ； air toxics ； dispersion model