The Impact of MMT Gasoline Additive on Exhaust Emissions and Fuel Economy of Low Emission Vehicles (LEV)

Author(s):  
Jack D. Benson ◽  
Gregory Dana
2000 ◽  
Author(s):  
K. M. Jefferd ◽  
J. S. Rogerson ◽  
D. E. Copp ◽  
R. L. Brundle ◽  
M. A. Huntly

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4034
Author(s):  
Paolo Iodice ◽  
Massimo Cardone

Among the alternative fuels existing for spark-ignition engines, ethanol is considered worldwide as an important renewable fuel when mixed with pure gasoline because of its favorable physicochemical properties. An in-depth and updated investigation on the issue of CO and HC engine out emissions related to use of ethanol/gasoline fuels in spark-ignition engines is therefore necessary. Starting from our experimental studies on engine out emissions of a last generation spark-ignition engine fueled with ethanol/gasoline fuels, the aim of this new investigation is to offer a complete literature review on the present state of ethanol combustion in last generation spark-ignition engines under real working conditions to clarify the possible change in CO and HC emissions. In the first section of this paper, a comparison between physicochemical properties of ethanol and gasoline is examined to assess the practicability of using ethanol as an alternative fuel for spark-ignition engines and to investigate the effect on engine out emissions and combustion efficiency. In the next section, this article focuses on the impact of ethanol/gasoline fuels on CO and HC formation. Many studies related to combustion characteristics and exhaust emissions in spark-ignition engines fueled with ethanol/gasoline fuels are thus discussed in detail. Most of these experimental investigations conclude that the addition of ethanol with gasoline fuel mixtures can really decrease the CO and HC exhaust emissions of last generation spark-ignition engines in several operating conditions.


Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1046
Author(s):  
Maksymilian Mądziel ◽  
Tiziana Campisi ◽  
Artur Jaworski ◽  
Giovanni Tesoriere

Urban agglomerations close to road infrastructure are particularly exposed to harmful exhaust emissions from motor vehicles and this problem is exacerbated at road intersections. Roundabouts are one of the most popular intersection designs in recent years, making traffic flow smoother and safer, but especially at peak times they are subject to numerous stop-and-go operations by vehicles, which increase the dispersion of emissions with high particulate matter rates. The study focused on a specific area of the city of Rzeszow in Poland. This country is characterized by the current composition of vehicle fleets connected to combustion engine vehicles. The measurement of the concentration of particulate matter (PM2.5 and PM10) by means of a preliminary survey campaign in the vicinity of the intersection made it possible to assess the impact of vehicle traffic on the dispersion of pollutants in the air. The present report presents some strategies to be implemented in the examined area considering a comparison of current and project scenarios characterized both by a modification of the road geometry (through the introduction of a turbo roundabout) and the composition of the vehicular flow with the forthcoming diffusion of electric vehicles. The study presents an exemplified methodology for comparing scenarios aimed at optimizing strategic choices for the local administration and also shows the benefits of an increased electric fleet. By processing the data with specific tools and comparing the scenarios, it was found that a conversion of 25% of the motor vehicles to electric vehicles in the current fleet has reduced the concentration of PM10 by about 30% along the ring road, has led to a significant reduction in the length of particulate concentration of the motorway, and it has also led to a significant reduction in the length of the particulate concentration for the access roads to the intersection.


Author(s):  
Sandro P. Nüesch ◽  
Anna G. Stefanopoulou ◽  
Li Jiang ◽  
Jeffrey Sterniak

Highly diluted, low temperature homogeneous charge compression ignition (HCCI) combustion leads to ultra-low levels of engine-out NOx emissions. A standard drive cycle, however, would require switches between HCCI and spark-ignited (SI) combustion modes. In this paper a methodology is introduced, investigating the fuel economy of such a multimode combustion concept in combination with a three-way catalytic converter (TWC). The TWC needs to exhibit unoccupied oxygen storage sites in order to show acceptable performance. But the lean exhaust gas during HCCI operation fills the oxygen storage and leads to a drop in NOx conversion efficiency. Eventually the levels of NOx become unacceptable and a mode switch to a fuel rich combustion mode is necessary in order to deplete the oxygen storage. The resulting lean-rich cycling leads to a penalty in fuel economy. In order to evaluate the impact of those penalties on fuel economy, a finite state model for combustion mode switches is combined with a longitudinal vehicle model and a phenomenological TWC model, focused on oxygen storage. The aftertreatment model is calibrated using combustion mode switch experiments from lean HCCI to rich spark-assisted HCCI and back. Fuel and emissions maps acquired in steady state experiments are used. Two depletion strategies are compared in terms of their influence on drive cycle fuel economy and NOx emissions.


Author(s):  
Myoungjin Kim ◽  
Sihun Lee ◽  
Wootae Kim

In-cylinder flows such as tumble and swirl have an important role on the engine combustion efficiencies and emission formations. In particular, the tumble flow, which is dominant in-cylinder flow in current high performance gasoline engines, has an important effect on the fuel consumptions and exhaust emissions under part load conditions. Therefore, it is important to know the effect of the tumble ratio on the part load performance and optimize the tumble ratio of a gasoline engine for better fuel economy and exhaust emissions. First step in optimizing a tumble flow is to measure a tumble ratio accurately. In this research the tumble flow was measured, compared and correlated using three different measurement methods: steady flow rig, 2-Dimensional PIV, and 3-Dimensional PTV. Engine dynamometer test was performed to find out the effect of the tumble ratio on the part load performance. Dynamometer test results of high tumble ratio engine showed faster combustion speed, retarded MBT timing, higher exhaust emissions, and a better lean burn combustion stability. Lean limit of the baseline engine was expanded from A/F=18:1 to A/F=21:1 by increasing a tumble ratio using MTV.


Author(s):  
Alex Oliveira ◽  
Junfeng Yang ◽  
Jose Sodre

Abstract This work evaluated the effect of cooled exhaust gas recirculation (EGR) on fuel consumption and pollutant emissions from a diesel engine fueled with B8 (a blend of biodiesel and Diesel 8:92%% by volume), experimentally and numerically. Experiments were carried out on a Diesel power generator with varying loads from 5 kW to 35 kW and 10% of cold EGR ratio. Exhaust emissions (e.g. THC, NOX, CO etc.) were measured and evaluated. The results showed mild EGR and low biodiesel content have minor impact of engine specific fuel consumption, fuel conversion efficiency and in-cylinder pressure. Meanwhile, the combination of EGR and biodiesel reduced THC and NOX up to 52% and 59%, which shows promising effect on overcoming the PM-NOX trade-off from diesel engine. A 3D CFD engine model incorporated with detailed biodiesel combustion kinetics and NOx formation kinetics was validated against measured in-cylinder pressure, temperature and engine-out NO emission from diesel engine. This valid model was then employed to investigate the in-cylinder temperature and equivalence ratio distribution that predominate NOx formation. The results showed that the reduction of NOx emission by EGR and biodiesel is obtained by a little reduction of the local in-cylinder temperature and, mainly, by creating comparatively rich combusting mixture.


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