Specific gravity naphtha

Properties. The properties of the Hquid fuel oil produced by the SRC-II process are iafluenced by the particular processiag coafiguratioa. However, ia geaeral, it is an oil boiling between 177 and 487°C, having a specific gravity of 0.99—1.00, and a viscosity at 38°C of 40 SUs (123). Pipeline gas, propane and butane (LPG), and naphtha are also recovered from an SRC-II complex. 

When simple Hquids like naphtha are cracked, it may be possible to determine the feed components by gas chromatography combined with mass spectrometry (gc/ms) (30). However, when gas oil is cracked, complete analysis of the feed may not be possible. Therefore, some simple definitions are used to characterize the feed. When available, paraffins, olefins, naphthenes, and aromatics (PONA) content serves as a key property. When PONA is not available, the Bureau of Mines Correlation Index (BMCI) is used. Other properties like specific gravity, ASTM distillation, viscosity, refractive index. Conradson Carbon, and Bromine Number are also used to characterize the feed. In recent years even nuclear magnetic resonance spectroscopy has been... 

The data from the density (specific gravity) test method (ASTM D1298 IP 160) provides a means of identification of a grade of naphtha but is not a guarantee of composition and can only be used to indicate evaluate product composition or quality when used in conjunction with the data from other test methods. Density data are used primarily to convert naphtha volume to a weight basis, a requirement in many of the industries concerned. For the necessary temperature corrections and also for volume corrections, the appropriate sections of the petroleum measurement tables (ASTM D1250 IP 200) are used. 

The selection of steam cracker feedstock is mainly driven by market demand as different feedstock qualities produce different olefins yields. One of the commonly used feed quality assessment methods in practice is the Bureau of Mines Correlation Index (BMCI) (Gonzalo et al., 2004). This index is a function of average boiling point and specific gravity of a particular feedstock. The steam cracker feed quality improves with a decrease in the BMCI value. For instance, vacuum gas oil (VGO) has a high value of BMCI and, therefore, is not an attractive steam cracker feed. The commonly used feedstocks in industry are naphtha and gas oil. 

Some specific gravities of common petroleum liquids are 1 to 1.1 for asphalt, 0.8 for gasoline, and 0.6 for naphtha. 

For the specific case of a naphtha of specific gravity = 0.713 and an atmospheric gas oil with specific gravity di s 0.841, a Linde study compares the performance obtained in the same fiimace with these two feedstocks, at different treatment severities, a concept defined in this case by the weight ratio of the propylene to ethylene produced (Fig. ZIO). 

Diluting these emulsions of heavy oils with light solvents—e.g., kerosene, solvent naphtha, benzene, etc.—reduces the specific gravity of the oil phase of the emulsions below that of water and lowers the vis-... 

A shell and tube cooler in an aromatics complex cools 26,200 Ib/h of naphtha (specific gravity 0.78, viscosity 0.007 cP). The cooler has 347 tubes, 16 ft long, 3/4 inch diameter. If the naphtha is on the tube side, estimate the tube side pressure drop. 

Correlative methods have long been used as a way of dealing with the complexity of various petroleum fractions, including naphtha. Relatively easy to measure physical properties such as density (or specific gravity) (ASTM D-2935 ASTM D-3505, ASTM D-4052) are also required. Viscosity (ASTM D-88, ASTM D-445, ASTM D-2161, IP 71), density (ASTM D-287, ASTM D-891, ASTM D-941, ASTM D-1217, ASTM D-1298, ASTM D-1555, ASTM D-1657, ASTM D-2935, ASTM D-4052, ASTM D-5002, IP 160,... 

Commercial naphthas are complex mixtures of a large number of different isomers and are generally characterized by specific gravity and boiling curves (TBP curves or ASTM D86). The relevant properties of different straight run naphthas are reported in Table VIII. The sulphur content is usually lower than 2% and nitrogen is in the order of a few ppm. Light and heavy naphthas are... 

Naphtha feed is often characterized using PINA analysis that simply is the weight % of K-paraffin, Ao-paraffin, naphthene and aromatic compounds. If the typical commercial indexes (specific gravity, PINA analysis and TBP curves or ASTM D86) are used properly, it is possible to empirically derive detailed naphtha composition by referring to the four different hydrocarbon classes and only to a limited number of reference components within each class. In fact, the PINA information indicates the relative abundance of the four different classes directly. The specific gravity and boiling curve allow the specification of the initial and final cuts of the hydrocarbon mixture as well as the relative presence and distribution of the reference pseudo components inside each fraction. 

In addition, a method of petroleum classification has been developed that is based on other properties as well as the density of selected fractions. The method consists of a preliminary examination of the aromatic content of the fraction boiling up to 145°C as well as that of the asphaltene content, followed by more detailed examination of the chemical composition of the naphtha (b.p. <200°C). For this examination, a graph (a composite of curves expressing the relation between percentage distillate from the naphtha, the aniline point, refractive index, specific gravity, and the boiling point) is used. The aniline point after acid extraction is included in order to estimate the paraffin-naphthene ratio. 

Toluene, CeHs.CHs, is obtained from coal-tar. It is formed in appreciable quantities when kerosene is heated under pressure (Rittman process, 30), and when the higher homologues of benzene, such as the xylenes, cumenes, etc., are boiled with anhydrous aluminium chloride. The latter process was used to some extent during the war to make toluene from solvent naphtha (421). Toulene boils at 111° and has the specific gravity 0.865 ( ). It may be prepared by the use of the general methods which have been described. 

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