Gasoline boiling point

Applications of IR analyzers include the measurement of ammonia, CO, C02, ethylene, hexane, methane, moisture, nitrous oxide, propane, and sulfur dioxide. NIR analyzers can detect the concentrations of benzene, caustic, cetane, gasoline boiling point, heating value, molecular weight, octanes, protein, and p-xylene. The measurement errors of these analyzers are IR—2% FS, NIR—1% FS. 

Eleven different groups of crude oils haye been defined according to the densities of their heavy gasoline cuts (100-200°C) and their residues with boiling points above 350°C as shown in Table 3.1. 

The resolution of capillary columns enables the separation of all principal components of a straight-run gasoline. The most frequently used stationary phases are silicone-based, giving an order of hydrocarbon elution times close to the order of increasing boiling point. 

This analysis, abbreviated as FIA for Fluorescent Indicator Adsorption, is standardized as ASTM D 1319 and AFNOR M 07-024. It is limited to fractions whose final boiling points are lower than 315°C, i.e., applicable to gasolines and kerosenes. We mention it here because it is still the generally accepted method for the determination of olefins. 

The accuracy depends on the fraction distilled it deviates particularly when determining the initial and final boiling points the average error can exceed 10°C. When calculating the ASTM D 86 curve for gasoline, it is better to use the Edmister (1948) relations. The Riazi and Edmister methods lead to very close results when they are applied to ASTM D 86 calculations for products such as gas oils and kerosene. 

Isopropyl Ether. Isopropyl ether is manufactured by the dehydration of isopropyl alcohol with sulfuric acid. It is obtained in large quantities as a by-product in the manufacture of isopropyl alcohol from propylene by the sulfuric acid process, very similar to the production of ethyl ether from ethylene. Isopropyl ether is of moderate importance as an industrial solvent, since its boiling point Hes between that of ethyl ether and acetone. Isopropyl ether very readily forms hazardous peroxides and hydroperoxides, much more so than other ethers. However, this tendency can be controlled with commercial antioxidant additives. Therefore, it is also being promoted as another possible ether to be used in gasoline (33). 

Evaporative emissions from vehicle fuel systems have been found to be a complex mixture of aliphatic, olefinic, and aromatic hydrocarbons [20,24,33]. However, the fuel vapor has been shown to consist primarily of five light paraffins with normal boiling points below 50 °C propane, isobutane, n-butane, isopentane, and n-pentane [33]. These five hydrocarbons represent the more volatile components of gasoline, and they constitute from 70 to 80 per cent mass of the total fuel vapor [24,33]. 

Class IB liquids with flashpoints below 73°F and boiling points at or above 100°F. Examples of Class IB flammable liquids are benzene, gasoline, and acetone (NFPA Diamond 3). 

Chemical Designations - Synonyms No common synonyms Chemical Formula Not pertinent. Observable Characteristics - Physical State (as shipped) Liquid Color. Colorless Odor Gasoline. Physical and Chemical Properties - Physical State at 15 XI and I atm. Liquid Molecular Weight Not pertinent Boiling Point at I atm. 58 - 275, 14 - 135, 287 - 408 Freezing Point Not pertinent Critical Temperature Not pertinent Critical Pressure Not pertinent Specific Gravity 0.71 - 0.75 at 15°C, (liquid) Vapor (Gas) Specific Gravity 3.4 Ratio cf Specific Heats cf Vapor (Gas) Not pertinent Latent Heat of Vaporization 130 - 150, 71 -81, 3.0 - 3.4 Heat of Combustion -18,720, -10,400, -435.4 Heat of Decomposition Not pertinent. 

Figure 2-77 shows how the weight distributions of the different molecular types vary during the fractional distillation of a naphthenic crude oil. Saturated aliphatic hydrocarbons (i.e., paraffins and naphthenes) are the predominant constituents in the light gasoline fraction. As the boiling point is raised, the paraffin content decreases, and the NSO content increases continuously. About 75 wt% of tbe residuum is composed of aromatics and NSO compounds. 

The reactor yield is then determined by performing a component balance. The amount of C5+ in the gasoline boiling range is calculated by subtracting the C4 and lighter components from the total gas plant products. Example 5-4 shows the step-by-step calculation of the component yields. The summary of the results, normalized but unadjusted for the cut points is shown in Table 5-4. 

Aromatic levels and carbon content of the gasoline also have a significant effect on the tailpipe emissions of HC and CO. Because of their high heat of vaporization and high boiling point (see Figure 10-1), aromatics do not vaporize readily. This is an incentive to minimize aromatics. 

Petroleum refining begins by fractional distillation of crude oil into three principal cuts according to boiling point (bp) straight-run gasoline (bp 30-200 °C), kerosene (bp 175-300 °C), and heating oil, or diesel fuel (bp 275-400 °C). Further distillation under reduced pressure then yields... 

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