Gasoline properties

Proper prediction of the octane of refinery blends is important because octane has traditionally been one of the most expensive gasoline properties... 

Starting January 1998, the EPA s Complex Model went into effect. The Complex Model provides a set of equations that predict VOC, NO, and toxic emissions, using eight gasoline properties. These properties are RVP, oxygen, aromatics, benzene, olefins, sulfur, E200. 

TABLE 3-8. Effect of Ethanol Addition on Gasoline Properties... 

Properties for M85 and E85 extrapolated from M100, E100, and gasoline properties, except where noted. 

Ignatius, J., Jarelin, H., and Lindquist, P., Use of TAME and heavier ethers to improve gasoline properties, Hydrocarbon Processing, Feb. 51—53 (1995). 

The effects of gasoline properties and composition on regulated emissions (HC, CO and NO c) are complex and there are large variations in sensitivity between vehicles. Much work has been done, but there is a clear need for further work in Europe, especially on sulfur effects and aromatics/distillation. This will be covered in the new EPEFE programme. 

Effect on Gasoline Properties. The naphtha fed to the reforming reactor contains alkylcyclopentanes. These compounds can be isomerized, and then almost immediately they undergo dehydrogenation to an aromatic. One example is the conversion of methylcyclopentane (MCP) to benzene (B). The overall reaction is shown in (Scheme 3). 

Effect on Gasoline Properties. The isomerization of a paraffin rearranges the molecule without changing the density. There is a large increment in the octane number of the gasoline, upon paraffin isomerization. For example, in the case of ra-hexane, there is an increase of more than 60 octane numbers when isomerized to any isohexanes (see Table 1). 

Effect on Gasoline Properties. The re-paraffins are the main components of the feed reformers. The transformation of these low-octane number compounds into aromatics is the most important reaction in a reformer, since it produces the largest increases in the octane number (see Table 1), making it possible to obtain a product with octane number well above 80. The increase in octane number is larger for heavier paraffins. 

Effect on Gasoline Properties. The hydrocracking reaction is the C—C bond breaking catalyzed by the acid function. In this reaction, either a paraffin molecule is broken into two molecules of lower molecular weight, or a naphthene ring is opened. The aromatics are very difficult to be hydrocracked under normal reforming conditions. 

Gasoline Properties Using NIR SMLR model Spectroscopy PLS ... 

Sixteen different reformulated gasoline blends were tested with the current and older vehicles. Key reformulated gasoline properties were set at two levels. These properties included aromatics content, MTBE concentration, olefins level and 90% evaporation temperature, a measure of fuel boiling range. 

Stokes, G. M., Wear, C. C., Suarez, W., Young, G. W., (1990), "Impact of Operational and Catalytic Effects on FCC Gasoline Properties", NPRA Paper AM90-10, San Antonio. 

Christensen, E., Yanowitz, J., Ratcliff, M., McCormick, R.L., 2011a. Renewable oxygenate blending effects on gasoline properties. Energy Fuels 25 (10), 4723—4733. 

---