2025-11-25 カリフォルニア大学リバーサイド校（UCR）
＜関連情報＞
- https://news.ucr.edu/articles/2025/11/25/study-finds-lower-emissions-higher-ethanol-gasoline
- https://www.sciencedirect.com/science/article/abs/pii/S0016236123014497
カリフォルニア州のエタノール混合壁の拡大：E10とE15の排出量比較 Expanding the ethanol blend wall in California: Emissions comparison between E10 and E15
Tianbo Tang, Cavan McCaffery, Tianyi Ma, Peng Hao, Thomas D. Durbin, Kent C. Johnson, Georgios Karavalakis
Fuel Available online: 2 June 2023
DOI:https://doi.org/10.1016/j.fuel.2023.128836
Highlights
- Increasing the blend wall to E15 will not affect NOx emissions.
- Particulate emissions will be reduced with higher ethanol.
- Larger fraction of sub-23 nm particles with higher ethanol blending.
- Strong acetaldehyde increases with ethanol, but mixed monoaromatic hydrocarbon emissions.
- Greater life cycle GHG benefits with E15 than E10.
Abstract
This study assessed the potential of increasing ethanol content in California reformulated gasoline (CaRFG) by investigating the exhaust emissions from a fleet of 20 light-duty vehicles. A baseline CaRFG E10 (10% ethanol by volume) fuel was splash blended with denatured ethanol to create a E15 fuel. Each vehicle/fuel combination were exercised over triplicate Federal Test Procedure (FTP) cycles on a chassis dynamometer. Our results showed no statistically significant fuel effect on nitrogen oxide (NOx) emissions for E15, whereas total hydrocarbons (THC), non-methane hydrocarbons (NMHC), and carbon monoxide (CO) showed either marginally or statistically significant reductions for E15. Particulate matter (PM) and solid particle number emissions were positively impacted by ethanol, exhibiting statistically significant reductions. Acetaldehyde and ethanol emissions responded strongly with ethanol across the fleet of 20 vehicles, while formaldehyde emissions did not show a statistically significant effect. Monoaromatic species and 1,3-butadiene showed mixed results, with ethylbenzene and the xylene isomers showing strong fuel differences. Although no strong differences were found for carbon dioxide (CO2) emissions, E15 showed life cycle greenhouse gas (GHG) emissions savings when compared to E10.
