Density naphtha

Density Difference Between Particle and Liquid. Separation cannot take place if A6 = 0. Some mineral oils have the same density as water at room temperature. If it is heated to 80°C, the reduction of the density of water is less than that of the mineral oil, resulting ia the water becoming heavier. Therefore separation is possible. Dilution of a Hquid by a solvent, eg, molasses by water or heavy oil by naphtha, results ia lower density and lower viscosity of the Hquid. Solvent stripping takes place at a later stage. 

Liquid fuels for ground-based gas turbines are best defined today by ASTM Specification D2880. Table 4 Hsts the detailed requirements for five grades which cover the volatility range from naphtha to residual fuel. The grades differ primarily in basic properties related to volatility eg, distillation, flash point, and density of No. 1 GT and No. 2 GT fuels correspond to similar properties of kerosene and diesel fuel respectively. These properties are not limited for No. 0 GT fuel, which allows naphthas and wide-cut distillates. For heavier fuels. No. 3 GT and No. 4 GT, the properties that must be limited are viscosity and trace metals. 

Thiophene (C4H4S) is representative of the organic sulfur compounds that are hydrogenated in the commercial hyditodesulfurization of petroleum naphtha. Estimate both the combined and effective diflfusivities for thiophene in hydrogen at 660 °K and 3.04 MPa in a catalyst with a BET surface area of 168 m2/g, a porosity of 0.40, and an apparent pellet density of 1.40 g/cm3. A narrow pore sized distribution... 

A naphtha is desulfurized by reducing its thiophene content with hydrogen at 660 K and 30 atm.The reaction is apparently first order with k = 0.3 cc thiophene/(g catalyst)(sec). The catalyst particle diameter is 0.35 cm, true density 2.65 g/cc, specific surface 180 m2/g, porosity 40%. In an... 

In addition, a method of petroleum classification based on other properties as well as the density of selective fractions has been developed. The method consists of a preliminary examination of the aromatic content of the fraction boiling up to 145°C (295°F), as well as that of the asphaltene content, followed by a more detailed examination of the chemical composition of the naphtha (bp < 200°C < 390°F). For this examination a graph is nsed that is a composite of cnrves expressing the relation among the percentage distillate from the naphtha. 

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. 

Liquid products contain sulfur and nitrogen and must be hydroprocessed to improve quality. Separate hydroprocessing units for upgrading the naphtha, kerosene, and gas oil fractions can be used to optimize the overall process. Refined gas oil or diesel fuel is aromatic in character and contains more cycloparaffins than conventional crude oil. The resulting fuel is low in cetane number, high in density, and typically has very good low-temperature handling properties. 

As a rule of thumb one should approach a hydrocarbon spill (non-fire situation) under the assumption that the liquid is vaporizing (the vapors will be invisible) and that the liberated vapors are heavier than air unless proven otherwise. The expected conduct of a heavier-than-air vapor is for it to drop and spread at or below ground level much as a liquid would. The big difference is that a liquid will be visible and its boundaries well defined. One can expect that the invisible heavier-than-air vapor will settle and collect in low spots such as ditches, basements, sewers, etc. As the vapor navels, it will be mixing with the air, thus some portions of the cloud may be too rich to bum, other sections too lean, and still others well within the explosive range. Some typical vapor densities for petroleum products are 3 to 4 for gasoline, 2.5 for naphtha, and 1.1 for methanol. For comparison, the vapor density for hydrogen gas is 0.1. 

This is 2500 times faster than with gravity alone, but the residence time in the centrifuge would have to be about 20 minutes, which is not practical. To speed up the separation, naphtha is added to the level of 25%. This lowers the viscosity to about 4.5 mPa-s and lowers the density of the continuous phase to 0.88 g/mL. Note that now the water drops would sediment rather than cream under gravitational force, and while the emulsion density is much reduced, the absolute value of the density difference changes very little Ap = -0.07 g/mL originally, and becomes Ap = +0.09 g/mL The overall effect is to lower the viscosity by about two orders of magnitude. The droplet velocity now becomes (dx/dt)" = 1.1 cm/s, which yields a satisfactory residence time of about 8 seconds. 

Naphthalene (melting point 80.3°C, density 1.175, flash point 79°C) is very slightly soluble in water but is appreciably soluble in many organic solvents such as 1,2,3,4-tetrahydronaphthalene (tetralin), phenols, ethers, carbon disulfide, chloroform, benzene, coal-tar naphtha, carbon tetrachloride, acetone, and decahydronaphthalene (decalin). 

A new catalyst with long-term stability was developed for the aromatization of light naphtha. Our proprietary technique of steaming reduced acid site density of the external surface of the catalyst and minimized coke formation. The new catalyst enabled us to develop a new light naphtha aromatization (LNA) process using a conventional fixed bed unit. Idle heavy naphtha reformer can be converted to this process without large modification. 

Erionite has been synthesized at i00°-I50°C from a (Na,K) aluminosilicate gel with Si02/AUOs = 10. X-ray and electron diffraction results on the product show intergrowths of the related offretite structure, which is a large-pore zeolite. Adsorption capacity for n-hexane is consistent with the density but adsorption rates are far slower than for zeolite A. Adsorption rates for n-octane are even slower but still better than for natural erionite. Hydrocracking tests on a C /Cq naphtha show strong selectivity for converting normal paraffins to Cf gas, particularly propane. As temperature is increased, other components of the naphtha feed are cracked and selectivity decreases. 

The feedstocks (straight-mn naphtha (SRN) and a blend of SRN and hydrocracked naphtha) and hydrotreated products were analysed by ASTM methods for density, carbon, hydrogen, hydrocarbon and boiling point distribution. Total sulfur was determined by ASTM D-4045 method, mercaptan sulfur by the potentiometric method (ASTM D-3227 and UOP-212), disulfides by the UOP-202 method, polysulfides by polarography [1], and elemental sulfur by the UOP-286 method. The Perkin-Elmer gas chromatograph (Model 8700), equipped with a flame photometric detector (GC/FPD) and a DB-1 fused silica capillary column (30 m x 0.53 mm), was used for identification of individual sulfur compounds [2-6]. The sensitivity of the GC/FPD technique was maximized by optimizing the gas flow rates and temperature programming as presented elsewhere [1]. 

Analysis of the feedstocks, shown in Table 2, indicates that the density, refractive index and carbon content of the blend naphtha are higher than those of SRN. This was due to higher aromatics and naphthenes, lower alkanes and higher final boiling point. To study the effect of catalyst type on sulfitr compounds selectivity, the feedstock and products were characterized... 

The bitumen layer from the two separation processes is a similar density to water and also quite viscous. It contains some occluded water plus a small amount of mineral fines. By diluting this fraction with naphtha, in which the bitumen is soluble, the viscosity is decreased sufficiently to allow cleaner phase separation to take place. Phase separation, accelerated by centrifuging, produces separate streams of the wastewater (plus some mineral fines) and the naphtha solution of bitumen. Flash distillation of the naphtha solution then yields the crude bitumen product and recovers the naphtha for recycle. 

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,... 

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