Distillate properties

Cetane Index A calculated value which incorporates fuel distillation properties and °API which can be used to approximate the cetane number of a fuel. This method, however, does not provide information on the performance provided by a cetane improver. 

Several patents discuss the use of Raman spectroscopy to determine the properties of finished products.93 94 For reformulated gasoline, some of these properties include sulfur, olefin, benzene, volatile organic carbon (VOC), nitrogen oxides (NOx), aromatic contents, total air pollutants (TAPs), Reid Vapor Pressure (RVP), distillation properties, motor and research octane numbers, and drivability. For the octane numbers, the accuracy of the Raman method was limited by errors in the reference method. 

The medium oil contains quite low sulfur, but has a slightly lower pour point compared with commercial heavy oil A. It is used as a boiler fuel for the sewage treatment plant in Niigata city. The heavy fraction contains quite low sulfur and is used in a paper and pulp factory in Niigata city. The distillation properties of the oils are shown in Figure 26.3. 

Attempts have been made to define or classify petroleum based on various distillation properties when combined with another property such as density. It has been suggested that a crude should be called asphaltic if the distillation residue contained less than 2% wax and paraffinic if it contained more than 5%. A division according to the chemical composition of the 250-300°C (480-570°F) fraction has also been suggested (Table 2.1). 

Usually seven fractions provide the basis for a reasonably thorough evaluation of the distillation properties of the feedstock ... 

The solvent, alone or in a mixture, with water added if necessary, is placed in counter-current contact with the feed, and carries off the aromatics. The introduction of a reflux helps to remove nearly all the non-aromatics. The solvent is regenerated by distillation or reextraction. Distillation is normally carried out in two steps. The first exploits the extractive distillation property, thus increasing the purity of the aromatics, by using the paraffins leaving at the top (light paraffins and entrained benzene) as a backwash reflux. In the second, the solvent is separated by simple distillation and liberates the pure aromatics. The yield in the operating conditions selected is always very high (Table 4.4). 

Distillation curve of a gasoline with carves for distillate properties... 

In testing the steam distillation properties of solvent mixtures a Dean and Stark still head is very useful. 

Classification Petroleum distillate Properties Negligible sol. in water m.w. 212 sp.gr. 0.773 (15.6/15.6 C) vise. 2.53 cSt vapor pressure < 0.5 mm Hg (38 C) b.p. 251-280 C pour pt. 7 C flash pt. (PMCC) > 120 C autoignition temp. 210 C Toxicology ACGIH TLV 5 mg/m (oil mist) LD50 (oral, rat) > 5 g/kg, (skin, rabbit) > 3.16 g/kg high vapor cones, may cause eye/respiratory tract irritation, headaches, dizziness, anesthesia, drowsiness, unconsciousness, other CNS effects death prolonged/repeated skin contact may cause irritation, dermatitis may cause eye irritation if aspirated, may cause miid to severe puimonary injury, death TSCA iisted... 

In this part will be discussed methods for estimating the yields and properties of the various products which can be produced off the atmospheric tower. The general method of attack will be to determine distillation properties of the desired products and apply these to the whole crude TBP curve in order to estimate volumetric yields. Volumetric yields are then used to obtain product gravities, molecular weights and other properties from the crude assay. There are many ways to define a product slate, but most of these are based on specifying certain ASTM distillation tern-... 

One of the advantages of GC-MS over an IR spectroscopic analyzer is the ability to measure distillation characteristics as well as predict other properties. There are several other materials that can be directly measured and reported. These include benzene, total aromatics, oxygenates, certain sulfur compounds and additives. The properties that can be predicted include (among others) cetane number and index, research and motor octanes, refractive index, distillation properties, aniline point, cloud point, pour point, volatility, flash point, density, conductivity, and viscosity [57]. 

Relative Bias—There exists a bias between the empirical results of distillation properties obtained by this test method and the true boiling point distillation curve obtained by Test Method D 2892. The amount of relative bias between the two test methods has not been determined. 

Absolute Bias—Since there is no accepted reference material suitable for determining the bias for the procedure in Test Method D 2892 in determining distillation properties of crude petroleum, bias cannot be determined. 

Chem. Descrip. Organic defoamer Uses Defoamer for protein and starch, distillation Properties Liq. sp.gr. 0.956 vise. 700 cps flash pt. (PMCC) > 300 F Mazu DF 203 [Emerald Foam Control]... 

We can add imports by clicking the Add Import button in the Imported Variables section. We add variables through the Variable Navigator interface. Since we are interested in the distillation properties of the each product stream, we select the Calculator section and the appropriate distillahon point (10%). We can add the same information for each stream as show in Figure 2.87. We add the 10% distillation point for each stream into the spreadsheet in Figure 2.88. 

Various classifications of petroleum are reported in the literature, which take into consideration crude oil properties, distillates properties, chemical structure, origin, etc. Given the great amount of effort that experts around the world have put into these definitions, it is not necessary to generate new criteria. 

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