Fuels alternate emissions

TABLE 12-13. Alternative Fuel Emission Levels from a Dl Engine Compared to Diesel EURO II Limits... 

Keywords Air quality, Alternative fuels, Emission-control technologies, Transport, Vehicle emissions... 

Wolf, G. T., and Frosch, R, A., Impact of alternative fuels on vehicle emissions of greenhouse gases, j. Air Waste Manage. Assoc. 41(12) 1172-1176 (December 1991). 

In the United States, in particular, recent legislation has mandated sweeping improvements to urban air quality by limiting mobile source emissions and by promoting cleaner fuels. The new laws require commercial and government fleets to purchase a substantial number of vehicles powered by an alternative fuel, such as natural gas, propane, electricity, methanol or ethanol. However, natural gas is usually preferred because of its lower cost and lower emissions compared with the other available alternative gas or liquid fuels. Even when compared with electricity, it has been shown that the full fuel cycle emissions, including those from production, conversion, and transportation of the fuel, are lower for an NGV [2]. Natural gas vehicles offer other advantages as well. Where natural gas is abundantly available as a domestic resource, increased use... 

Compressed Natural Gas (CNG) an alternative fuel for motor vehicles considered one of the cleanest because of low hydrocarbon emissions and its vapors are relatively non-ozone producing. However, vehicles fueled with CNG do emit a significant quantity of nitrogen oxides. 

Fuel cycle emissions are all the emissions involved in producing, transmitting, and using an alternative fuel. For example, for hydrogen made from natural gas, there would be emissions of CO, and nitrogen... 

Most urban rail service is electric-powered and most urban bus service is diesel-powered, although diesel rail and electric bus operations do exist, as noted above. The efficiency and environmental impacts of electricity depend gi eatly on the source of electric power. Although electric vehicles produce no tailpipe emissions, generation of electricity can produce significant emissions that can travel long distances, Eor example, coal-powered electricity plants produce particulate emissions that travel halfway across North America, Urban buses also can be powered by a variety of alternative fuels. 

In the longer term, more exotic technologies, such as fuel cells powered by hydrogen, may be feasible. These technologies are fai from being economically feasible, but rapid progress is being made. However, as conventional vehicles become cleaner, the relative emissions-reduction benefits from alternative fuels declines. 

Beer T, Morgan G, Lepszewicz 1, Anyon P, Edwards 1, Nelson P, Watson H, Williams D (2001) Comparison of transport fuels life-cycle emission analysis of alternative fuels for heavy vehicles. CSIRO (Commonwealth Scientific and Industrial Research Organization), Australia... 

Automotive emission control, 10 30-67 for alternative fuels, 10 59-60 alternative systems, 10 58-59 catalytic converter chemical reactions and surface chemistry, 10 46—50 catalytic converter design, 10 39—46 diesel engine, 10 60-62 emission control system, 10 38-39 emission regulation and testing, 10 31-35... 

Chapter one is an overview of the energy evolution. It introduces the technology and emission issues, safety, and alternative fuels such as natural gas, hydrogen gas, methanol, ethanol and fuel cell power. 

Methanol also seems to biodegrade quickly when spilled and it dissolves and dilutes rapidly in water. It has been recommended as an alternative fuel by the EPA and the DOE, partly because of reduced urban air pollutant emissions compared to gasoline. Most methanol-fueled vehicles use a blend of 85% methanol and 15% gasoline called M85. Building a methanol infrastructure would not be as difficult as converting to hydrogen. While methanol can be produced from natural gas, it can also be distilled from coal or even biomass. In the 1980s, methanol was popular for a brief time as an internal-combustion fuel and President Bush even discussed this in a 1989 speech. 

In the first half of the 21st century, alternative fuels could achieve greater emissions and gas savings at lower cost, reducing emissions in... 

Irrespective of the fuel supply chain, alternative fuels have generally lower tailpipe emissions in terms of local pollutants (such as NO, CO, S02, VOC and particle emissions) than conventional gasoline and diesel engines for instance, natural gas completely eliminates particle emissions synfuels are manufactured with very low sulphur and aromatic contents alcohol-based fuels have high octane numbers, which... 

A combined comparative WTW analysis of specific global emissions and fuel supply costs is typically presented in a pathway portfolio analysis. Portfolio analysis helps to identify rapidly those alternative fuels and drive trains, or combinations of these, which can lead to the highest specific GHG emission savings. 

Well-to-wheel analysis is a specific form of life-cycle analysis (LCA). In contrast to WTW analysis, LCA typically also takes factors other than global GHG emissions of a product or an energy carrier into consideration (such as air pollutants), including provision of all construction materials for the necessary processing plants and, furthermore, plant decommissioning. The full detail of a general LCA analysis is not needed at the level of policy discussion to reach a broad consensus on alternative fuels or drive systems. As a subset of WTW analysis, well-to-tank (WTT) analysis is often used to separate environmental or economic effects of fuel supplies and drive systems. 

In Section 7.3, process-specific technical information on alternative fuels, which is needed for the WTW analysis is presented, and in Section 7.4 drive-system-specific data are provided, which are then merged in a WTW analysis of complete energy chains in comparison in Section 7.5. In reality, the potential number of realistic alternative fuel chains and drive system combinations is much larger. Owing to limited space, a set of most relevant processes is presented. A separate section (7.6) discusses the resource utilisation of the energy chains presented in Section 7.5. Section 7.7 finally combines specific GHG emissions for relevant alternative fuel supply chains with specific costs in a portfolio analysis. 

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