Emissions From Light-Duty Passenger Cars Fueled With Ternary Blend of Gasoline, Methanol, and Ethanol

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Chuanzhen Zhang ◽  
Yunshan Ge ◽  
Jianwei Tan ◽  
Lan li ◽  
Zihang Peng ◽  
...  

In this study, the emissions from three passenger cars with gasoline, methanol, ethanol, and their blend were tested. The results show that the CO and HC emissions from the exhaust of the vehicles fueled with E7.5/M7.5 decrease compared with those from the vehicles fueled with the gasoline, E10 or M15, while NOx emissions increase by 7.5–25.8%. Formaldehyde and acetaldehyde are found higher for the vehicles fueled with E7.5/M7.5, whereas a series of volatile compounds become lower. Evaporative emissions of the vehicles fueled with E7.5/M7.5 were higher than those of the vehicles fueled with gasoline, by a range of 16.39–28.28%.

Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1125
Author(s):  
Hui Mei ◽  
Lulu Wang ◽  
Menglei Wang ◽  
Rencheng Zhu ◽  
Yunjing Wang ◽  
...  

On-road exhaust emissions from light-duty vehicles are greatly influenced by driving conditions. In this study, two light-duty passenger cars (LDPCs) and three light-duty diesel trucks (LDDTs) were tested to investigate the on-road emission factors (EFs) with a portable emission measurement system. Emission characteristics of carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOx) emitted from vehicles at different speeds, accelerations and vehicle specific power (VSP) were analyzed. The results demonstrated that road conditions have significant impacts on regulated gaseous emissions. CO, NOx, and HC emissions from light-duty vehicles on urban roads increased by 1.1–1.5, 1.2–1.4, and 1.9–2.6 times compared with those on suburban and highway roads, respectively. There was a rough positive relationship between transient CO, NOx, and HC emission rates and vehicle speeds, while the EFs decreased significantly with the speed decrease when speed ≤ 20 km/h. The emissions rates of NOx and HC tended to increase and then decrease as the acceleration increased and the peak occurred at 0 m/s2 without considering idling conditions. For HC and CO, the emission rates were low and changed gently with VSP when VSP < 0, while emission rates increased gradually with the VSP increase when VSP > 0. For NOx NOx emission rates were lower and had no obvious change when VSP < 0. However, NOx emissions were positively correlated with VSP, when VSP > 0.


2011 ◽  
Vol 45 (39) ◽  
pp. 7053-7063 ◽  
Author(s):  
David C. Carslaw ◽  
Sean D. Beevers ◽  
James E. Tate ◽  
Emily J. Westmoreland ◽  
Martin L. Williams

Author(s):  
Sanjana Ahmad ◽  
David L. Greene

Since 1975, the fuel economy of passenger cars and light trucks has been regulated by the corporate average fuel economy (CAFE) standards, established during the energy crises of the 1970s. Calls to increase fuel economy are usually met by a fierce debate on the effectiveness of the CAFE standards and their impact on highway safety. A seminal study of the link between CAFE and traffic fatalities was published by R. W. Crandall and J. D. Graham in 1989. They linked higher fuel economy levels to decreases in vehicle weight and correlated the decline in new car weight with about a 20% increase in occupant fatalities. The time series available to them, 1947–1981, includes only the first 4 years of fuel economy regulation, but any statistical relationship estimated over such a short period is questionable. This paper reexamines the relationship between U.S. light-duty vehicle fuel economy and highway fatalities from 1966 to 2002. Cointegration analysis reveals that the stationary linear relationships between the average fuel economy of passenger cars and light trucks and highway fatalities are negative: higher miles per gallon is significantly correlated with fewer fatalities. Log–log models are not stable and tend to produce statistically insignificant (negative) relationships between fuel economy and traffic fatalities. These results do not definitively establish a negative relationship between light-duty vehicle fuel economy and highway fatalities; instead they demonstrate that national aggregate statistics cannot support the assertion that increased fuel economy has led to increased traffic fatalities.


Author(s):  
Parisa Bastani ◽  
John B. Heywood ◽  
Chris Hope

The U.S. Department of Transport and EPA have recently proposed further regulation of the light-duty vehicle corporate average fuel economy and GHG emissions for model years 2017 to 2025. Policy makers are setting more stringent targets out to 2025 in a context of significant uncertainty. These uncertainties need to be quantified and taken into account systematically when evaluating policies. In this paper, a stochastic technology and market vehicle fleet analysis is carried out, using the STEP (Stochastic Transport Emissions Policy model), to assess the probability of meeting the proposed CAFE targets in 2016 and 2025, and identify factors that play key roles in the near and midterm. Our results indicate that meeting the proposed targets requires (a) aggressive technological progress rate and deployment, (b)aggressive market penetration of advanced engines and powertrains, (c) aggressive vehicle downsizing and weight reduction, and (d) a high emphasis on reducing fuel consumption. Three scenarios are examined to assess the likelihood of meeting the proposed targets. The targets examined here, 32.5 and 34.1 mpg in 2016 and 44 and 54.5 mpg in 2025, are reduced from the nominal CAFE values after allowing for the various credits in the proposed rulemaking. The results show that there is about a 42.5% likelihood of the passenger cars average fuel economy falling below 32.5 mpg and a 5.3% likelihood of it exceeding 34.1 mpg in 2016, and about a 4% chance of it exceeding 44 mpg in 2025, under the plausible-ambitious scenario. Under the EPA/DOT preferred alternative scenario, the likelihood of passenger cars average fuel economy meeting or exceeding 34.1 mpg in 2016 and 44 mpg in 2025 increases to about 74% and 34.5% respectively. The probability of meeting these combined CAFE targets drops to less than 1% in both near and mid terms, once light trucks are included in the mix. This analysis quantifies the probability of meeting the targets therefore to enable risk-based contingency planning, and identifies key drivers of uncertainty where further strategic research is needed.


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