Reduced-emission vehicles

Emission Control Technologies. The California low emission vehicle (LEV) standards has spawned iavestigations iato new technologies and methods for further reducing automobile exhaust emissions. The target is to reduce emissions, especially HC emissions, which occur during the two minutes after a vehicle has been started (53). It is estimated that 70 to 80% of nonmethane HCs that escape conversion by the catalytic converter do so during this time before the catalyst is fully functional. 

List the alternatives that are possible to replace present automobiles with vehicles, or systems, that will reduce emissions of VOCs, NO, and CO,... 

Public concerns about air quality led to the passage of the Clean Air Act in 1970 to amendments to that act in 1977 and 1990. The 1990 amendments contained seven separate titles covering different regula-toiy programs and include requirements to install more advanced pollution control equipment and make other changes in industrial operations to reduce emissions of air pollutants. The 1990 amendments address sulfur dioxide emissions and acid rain deposition, nitrous oxide emissions, ground-level ozone, carbon monoxide emissions, particulate emissions, tail pipe emissions, evaporative emissions, reformulated gasoline, clean-fueled vehicles and fleets, hazardous air pollutants, solid waste incineration, and accidental chemical releases. 

Air quality suffers from this increasing congestion as well. Motor vehicles create the majority of air quality problems in urban areas, so for cities to comply with stringent ambient air quality standards, they will have to reduce motor vehicle emissions. Trucking accounts for only 4 percent of the U.S. motor vehicle fleet, yet can easily be responsible for 30 to 40 percent of the air quality problems because, in comparison to automobiles, the fleet is far older, is driven far more miles each year, and the emissions per vehicle are far greater. 

Transportation - production of gasoline and diesel from petroleum, fuel additives for greater efficiency and reduced emissions, catalytic converters, plastics to reduce vehicle weight and improve energy efficiency. 

West European production capacity for MTBE is estimated at 3.61m tonne, unchanged since 1998. In 1999, west European production, at around 3m tonne, represented an 83% operating rate. Consumption was considerably lower at 2.2m tonne. Europe s new gasoline specification, which came into force in January 2000, has lifted consumption to an estimated 2.7m tonne in 2000. MTBE is used to boost octane in gasoline and to promote cleaner burning and reduce harmful vehicle emissions. Demand to meet 2000 gasoline specifications in Europe boosted prices from 250 US dollars/tonne mid-1999 to touch 600 US dollars/tonne fob Rotterdam briefly in June 2000. There is increasing likelihood that the California ban on the use of MTBE, due to come into effect end 2002, will lead to further bans in the US marketplace. 

By 2010, Tier 2 standards should further reduce vehicle emissions by extending regulations to larger SUVs and passenger vans. The use of gasoline with a lower sulfur content will also reduce emissions and it also makes it easier to build cars that can achieve further reductions. These standards should allow new U.S. cars to be extremely free of air pollutants. But, the Clean Air Act does not cover vehicle C02 emissions. Many new cars are called near zero emissions by their manufacturers and may have tailpipe emissions cleaner than some urban air. Hydrogen fuel cell vehicles will have almost no emissions besides some water vapor and would be much cleaner. 

Issues of greenhouse-gas emissions and local air pollution, coupled with the increase in oil and gasoline prices, are triggering renewed interest in electric vehicles as a means to reduce emissions, improve the fuel economy of the present automobiles and reduce depletion of oil resources (CERA, 2008a 2008b Deutsche Bank, 2008). 

DOD is interested in new or novel advanced power and propulsion systems that will reduce fuel consumption, improve performance, extend vehicle range, reduce emissions, and reduce support costs. The Navy and Army are considering hybrids for ships, land vehicles, helicopters, and battlefield power requirements. 

Because of the low-sulfur, -nitrogen, and -aromatic content of Fischer-Tropsch fuels, there is renewed interest in these products. In two recent studies, Fischer-Tropsch diesel was evaluated and compared to an ultra-low sulfur California diesel and to a 49 cetane number, low-sulfur diesel. In the two studies, carbon monoxide, nitrogen oxide, hydrocarbon, particulate, and carbon dioxide emissions were reduced in vehicles fuels by Fischer-Tropsch diesel. The fuel economy, however, was also reduced. The low aromatic content and high concentration of waxlike hydrocarbons in Fischer-Tropsch diesel can lead to the need for special handling and treatment of the fuel to prevent gelling when used in cold-temperature conditions. 

Rueff, R. M The Cost of Reducing Emissions from Late-Model High-Emitting Vehicles Detected via Remote Sensing, J. Air Waste Manage. Assoc., 42, 921-925 (1992). 

Ce02-supported noble-metal catalysts such as Pt, Pd and Rh are of interest because of their importance in the so-called three-way converter catalysts (TWC), designed to reduce emissions of CO, NOx and uncombusted hydrocarbons in the environment and to purify vehicle-exhaust emissions. Such catalysts are also of current interest in steam reforming of methane and other hydrocarbons. Conventional practical catalysts for steam reforming consist of nickel supported on a ceramic carrier with a low surface area and are used at high temperatures of 900 C. This catalyst suffers from coke formation which suppresses the intrinsic catalyst activity. Promoters such as Mo are added to suppress coke formation. Recently, Inui etal(l991) have developed a novel Ni-based composite... 

Inserted into the exhaust system of vehicles, catalytic converters can reduce emissions of carbon monoxide and hydrocarbons by up to 90 per cent. The first catalytic converters used mainly platinum, but now palladium is the predominant catalytic metal. The metals are dispersed as tiny particles on a supporting framework of porous aluminium oxide (alumina) (Fig. 18). 

For diesel vehicles reductions in engine-out NOx emissions are harder to achieve, mainly due to the high combustion temperatures and oxygen-rich operational regime of the engine. Moreover, the effects of engine adjustments are limited due to a trade-off between NOx and particulate matter (PM) combustion-related measures which aim to reduce emissions of one pollutant (e.g. NOx) lead to an increase in emissions of the other (PM), and vice versa. Engine calibration is usually determined by the need to balance emissions of the two pollutants and to maximise fuel efficiency. Alternatively, emissions of either NOx or PM can be... 

The rationale of introducing natural gas in road traffic is primarily to reduce emissions. Several factors should be considered when making a decision on putting up an alternative fuel system. LNG is prone to be preferred by heavy vehicles only when payload is important as is the case for large distribution fleets like buses and trucks that operate within reasonable distance from the filling station. Whereas CNG turns better out for small, light vehicles when the routes are not fixed, and payload is no issue. 

Approaches to reduced motor vehicle emissions from cars fall into four categories ... 

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