Reformulated gasolines composition

The reduction in the lead content of gasoline and the introduction of reformulated gasoline have been very successful in reducing automobile emissions, due to changes in gasoline composition, with further improvements in fuel quality proposed for the early decades of this new millennium. These projections are accompanied by a noticeable and measurable decrease in crude oil quality, and the reformulated gasoline will help meet environmental regulations for emissions for liquid fuels but will be subject to continuous review because of the potential for environmental impact. 

Harley, R.A. and Coulter Burke, S.C. Relating liquid fuel and headspace vapor composition for California reformulated gasoline samples containing ethanol. Environ. Sci Technol, 34(19) 4088M094, 2000. 

Reformulated Gasoline (RFG) Gasoline that has its composition and/or characteristics altered to reduce vehicular emissions of pollutants, particularly pursuant to EPA regulations under the CAA. 

Shabtai, J.S., Zmierczak, W., and Chomet, E. (1997) Conversion of lignin to reformulated gasoline compositions. In Proceedings of the Third Biomass Conference of the Americas, (Ed. by Overend, R.P. and Chomet, E.), pp. 1037-1040. Elsevier Science Ltd., Oxford. 

Specific fuel compositions and components measured include iso-octane, xylene, methylcyclohexane, naptha and California reformulated gasoline. Additives examined include anti-oxidant No. 29 (2,6-Di-Tert-Butyl-4-methylphenol), anti-oxidant No. 22 (N, N -Di-Sec-Butyl-P-Phenylenediamine) and DMA-548. 

In this paper we describe some recent work done by Shell Research (which is submitted to the Tripartite Group) on the effects of gasoline composition and properties on vehicle emissions. In addition the manufacture of MTBE, a relatively new gasoline component and a major feature of US reformulated gasoline is reviewed. Catalysts appear to play an important role in both gasoline manufacture (illustrated for MTBE production) and gasoline end use (exhaust catalysis). 

In subsequent years, a new issue that bears on the composition of reformulated gasoline has surfaced. Concentrations of MTBE, presumably from gasoline leaks and spills that wash into natural waterways, have been found in drinking water. Because MTBE is not easily decomposed by natural processes or water treatment, it tends to remain where it has accumulated. It is reported to cause off tastes and odors in water. Also, it may be a carcinogen. In response to these concerns, a blue-ribbon panel of experts reviewed the evidence. In 2000, at their recommendation, efforts were begun to eliminate use of MTBE and promote further use of renewable oxygenates like ethanol. 

Reformulated gasoline Gasoline whose composition has been changed to reduce the percentage of olefins, aromatics, and sulfur and to add oxygenated compounds Reinforced plastics (composites) Plastics with fibers of a substance, such as graphite, imbedded in a polymer matrix Replication The process by which DNA is copied when a ceU divides... 

In the United States, measures to control the levels of automobile emissions and therefore of photochemical smog have become sophisticated since the first federal Clean Air Act of 1967. Modifications to the ICE have been extensive and included various redesigns of the combustion chamber, variations in the air-to-fuel ratio, reformulations of the composition of gasoline, the addition of the positive crankcase ventilation (PCV) valve to recirculate exhaust and underoxidized fuel gases through the combustion chambers, and the addition of carbon canisters that temporarily collect and then recirculate evaporated fuel from the gas tank and the fuel system. Some of these modifications have not always worked out as well as envisioned. For example, the 1990 modification to the Clean Air Act called for the addition of oxygenated... 

Shape-selective reactions have been extensively studied since zeohtes were first used in catalytic crackers during 1967" and Mobil has introduced several octane-boosting processes since 1968. ° Gasoline composition and octane number were reviewed when the Clean Air Act was passed in 1970. This mandated the phased removal of tetraethyl lead from gasoline as catalytic converters (see Chapter 11) were introduced to treat automobile exhaust gas. Octane boosting was the first in a series of measures that led to reformulated gasoline and improved exhaust emissions standards. 

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