21 research outputs found
Assessment of ambient air quality in the port of Naples
Two experimental monitoring campaigns were carried out in 2012 to investigate the air quality in the port of Naples, the most
important in southern Italy for traffic of passengers and one of the most important for goods. Therefore, it represents an
important air pollution source located close to the city of Naples. The concentrations of sulfur dioxide (SO2), nitrogen dioxide
(NO2), and BTEX (benzene, toluene, ethylbenzene, and xylenes) in the air were measured at 15 points inside the Naples port area
through the use of passive samplers. In addition, a mobile laboratory was positioned in a fixed point inside the port area to
measure continuous concentration of pollutants together with particulate matter, ambient parameters, and wind direction and
intensity. The pollution levels monitored were compared with those observed in the urban area of Naples and in other
Mediterranean ports. Even though the observation time was limited, measured concentrations were also compared with limit
values established by European legislation. All the measured pollutants were below the limits with the exception of nitrogen
dioxide: its average concentration during the exposition time exceeded the yearly limit value. A spatial analysis of data,
according to the measured wind direction and intensity, provided information about the effects that ship emissions have on
ambient air quality in the port area. The main evidence indicates that ship emissions influence sulfur dioxide concentration more
than any other pollutants analyze
Evaluation of Emission Factors for New Technology S. I. Euro 4 Cars
This research attempted to analyze the environmental impact of two available non-conventional vehicle technologies, highlighting the benefits in terms of emissions and fuel consumption reduction with respect to conventional vehicles. Moreover, tests were compared with predicted emissions of the conventional gasoline technology provided by the kinematic model developed. Results show that cold start strongly affects the emissions of CO, THC and NOX, which become very low during hot driving cycle. The existing emission model cannot be used to obtain a satisfactory prediction for hybrid car. But it could be proved that KEM emission model allows us to predict emission factor for conventional car and compressed natural gas. However, it is concluded that new experimental campaign with new technological cars might be interesting for future model developments
Emissions and energy consumption of a plug-in hybrid passenger car in Real Driving Emission (RDE) test
Abstract In the next years, the number of circulating plug-in hybrid electric vehicles was expected to increase worldwide. Hybrid electric/gasoline powertrain is considered a promising solution to meet the future goals of greenhouse gas emission reduction by road transport sector. This paper investigates the emissive and energetic behaviour of a plug-in hybrid electric passenger car over on road testing. Measurements of CO, CO2, NOx exhaust emissions and of main electric motor parameters were carried out by using portable emission measurement system over urban, rural and motorway routes in Naples (Italy). Routes were selected for complying with European Real Driving Emission (RDE) legislation. Moreover, an additional urban route, characterised by strong road grade and non-RDE compliant, was investigated. RDE test allowed to assess the influence of the battery state of charge, hybrid mode (charge sustaining and charge depleting), road grade and vehicle air conditioning on the exhaust emission and energy consumption. An overall advantage of charged battery and charge depleting mode was observed in terms of CO2 emissions and fuel consumption. CO and NOx emissions are strongly influenced by driving when the vehicle's internal combustion engine starts. When it occurs in motorway patterns, CO and NOx peak emissions are observed at tailpipe. Pure electric driving, with consequent zero emissions, are guaranteed over urban strong uphill when battery is full charged
Evaluation of organic micropollutants and fine particles in vehicle exhausts and in ambient air
The incredible increasing of the number of vehicles circulating in the Italian cities, occurred in the last fifteen years, is the main reason for still considering the traffic as the most important source of gaseous and particle pollutants in the urban atmosphere. The large volume of on road vehicles balances and deletes the positive effects in terms of exhaust emissions coming from the recent technological improvements regarding the engine combustion efficiency, the fuel quality and the after-treatment device performances. The urban air quality, in fact, is still greatly influenced by the elevated traffic volume, whose negative effects on the air pollution are made worse by the type of driving pattern enforced to the vehicle in a congested traffic situation. The most critical pollutant are represented by particulate matter and organic compounds, generally indicated as organic volatile compounds, which include carcinogenic species. Due to very dangerous effects of such pollutants for human health and environment, it is very important both to characterise the pollution source in terms of quantity and quality of emissions at the exhaust of the several in-use vehicle technologies and to establish the real contribution of road traffic to ambient air pollutant concentrations. This experimental work is aimed to carry out a comprehensive characterisation of volatile organic compounds and fine particles (in terms of mass, number and PAHs content) at the vehicle exhaust and in the ambient air, and to find a correlation between the exhaust pollution source and the air pollution in several traffic urban sites in Napoli. The methodology applied to realize this research plan involved two parallel experimental programmes: one aimed to measure exhaust emissions and the other to evaluate ambient air concentrations. Vehicle exhaust emission factors were evaluated by executing experimental tests on chassis dynamometer on a fleet including 20 in use vehicles, each characterised by a different engine technology and type approval stage. For the air quality monitoring, in situ sampling were realised in several sites of Napoli city: urban and sub-urban sites and road tunnels. Particulate and PAHs analyses were carried out both in vehicle exhaust and in ambient air, whereas BTEXs measurements were realized only in ambient air. One of the most relevant result was that, taking into account the traffic composition in the urban area of Napoli, the PTWs cover a not negligible role in the particulate urban air pollution. The road tunnels present the highest concentrations of BTEX and particulate, followed by the urban traffic sampling sites and the sub-urban ones. Due to many needed assumptions, a weak quantitative correlation was found between the air concentrations and exhaust emission rates produced by the real monitored traffic. More reliable correlations come from a qualitative analysis of pollutants measured in air and at the exhaust. A very good correlation was observed between the PAH ratios and BTEX ratios evaluated in both ambient air and exhaust emissions
Bioethanol/gasoline blends for fuelling conventional and hybrid scooter. Regulated and unregulated exhaust emissions
The aim of this experimental activity was to evaluate the influence of ethanol fuel on the pollutant emissions measured at the exhaust of a conventional and a hybrid scooter. Both scooters are 4-stroke, 125 cm3 of engine capacity and Euro 3 compliant. They were tested on chassis dynamometer for measuring gaseous emissions of CO, HC, NOx, CO2 and some toxic micro organic pollutants, such as benzene, 1,3-butadiene, formaldehyde and acetaldehyde. The fuel consumption was estimated throughout a carbon balance on the exhaust species. Moreover, total particles number with diameter between 20 nm up to 1 ÎŒm was measured. Worldwide and European test cycles were carried out with both scooters fuelled with gasoline and ethanol/gasoline blends (10/90, 20/80 and 30/70% vol). According to the experimental results relative to both scooter technologies, the addiction of ethanol in gasoline reduces CO and particles number emissions. The combustion of conventional scooter becomes unstable when a percentage of 30%v of bioethanol is fed; as consequence a strong increasing of hydrocarbon is monitored, including carcinogenic species. The negative effects of ethanol fuel are related to the increasing of fuel consumption due to the less carbon content for volume unit and to the increasing of formaldehyde and acetaldehyde due to the higher oxygen availability. Almost 70% of Ozone Formation Potential is covered by alkenes and aromatics
Influence of Performance Packages on Fuel Consumption and Exhaust Emissions of Passenger Cars and Commercial Vehicles under WLTP
The transportation sector is responsible for about 16% of worldwide greenhouse gas emissions. Despite efforts for a sensible reduction by means of new technologiesâ development, the average age of a vehicle fleet is 12.3 years in the European Union. In light of this, actions aiming at improving the efficiency of circulating vehicles can prove effective in the short to mid-term. Introducing performance packages in standard fuels could allow a reduction in the CO2 emissions of whole vehicle fleets without any modification to powertrain. Such a kind of additive is generally used in premium fuels; deposit control additives can reduce or control the deposits at intake valves and at nozzle holes with benefits for the fuel efficiency and exhaust emissions. Further improvements in combustion phasing can be achieved with cetane/octane improver. This paper aims to assess the influence of two performance packages on the exhaust emissions and fuel consumption of five vehicles set to be as representative as possible of circulating Italian passenger cars and light commercial fleet vehicles (LCVs). Based on the literature datasets, three Euro 4 vehicles were selected with a mileage representative of each single vehicle class: two passenger cars (one spark ignition and one diesel) and an LCV. Further, two diesel Euro 6 vehicles, a passenger car and an LCV, were tested to investigate the effect of fuel additives on the combustion of vehicles compliant with current homologation regulation. Exhaust emissions and fuel consumption were experimentally estimated on a chassis dynamometer over a worldwide harmonized light vehicles test cycle (WLTC) in a climate-controlled laboratory. Each vehicle was preliminarily tested when running with base fuel, then a 3000 km clean-up stage was performed using the additive package. Finally, WLTC tests were repeated. Results demonstrated the efficiency of the performance packages with a reduction between 1.2% (diesel Euro 6 passenger car) and 8.1% (diesel Euro 4 passenger car) in fuel consumption. Similar trends were found for CO2 emissions. Further, a sensible reduction in THCs, CO and PM was found for each vehicle class
Emission factors and fuel consumption of CNG buses in real driving conditions
This paper describes the results of an experimental campaign carried out on three urban buses fuelled by natural gas, aimed at measuring pollutant emissions and fuel consumption in real driving conditions. The buses, used for public transport in three Italian cities, were equipped with a Portable Emission Measurement System. Emission tests were performed over the routes on which the buses operate in their service, and cold start emissions were also investigated. The results showed that the differences in CO and NOx emissions can be attributed to the calibration of the fuel supply system. PM emissions were low and similar to those reported in the literature for other CNG buses, while CO2 and fuel consumption were affected by the driving cycle. Cold start strongly impacted CO and NOx emissions because of the effect of temperature on catalytic converter efficiency, with cold over-emissions strongly dependent on ambient and coolant temperatures at engine start
Experimental Comparative Study on Performance and Emissions of E85 Adopting Different Injection Approaches in a Turbocharged PFI SI Engine
This study examines the effects of ethanol and gasoline injection mode on the combustion performance and exhaust emissions of a twin cylinder port fuel injection (PFI) spark ignition (SI) engine. Generally, when using gasoline–ethanol blends, alcohol and gasoline are externally mixed with a specified blending ratio. In this activity, ethanol and gasoline were supplied into the intake manifold into two different ways: through two separated low pressure fuel injection systems (Dual-Fuel, DF) and in a blend (mix). The ratio between ethanol and gasoline was fixed at 0.85 by volume (E85). The initial reference conditions were set running the engine with full gasoline at the knock limited spark advance boundary, according to the standard engine calibration. Then E85 was injected and a spark timing sweep was carried out at rich, stoichiometric, and lean conditions. Engine performance and gaseous and particle exhaust emissions were measured. Adding ethanol could remove over-fueling with an increase in thermal efficiency without engine load penalties. Both ethanol and charge leaning resulted in a lowering of CO, HC, and PN emissions. DF injection promoted a faster evaporation of gasoline than in blend, shortening the combustion duration with a slight increase in THC and PN emissions compared to the mix mode