Sulfur distillation

Incompletely Characterized Carbon Sulfides. A poorly characterized black soHd, known as carsul, occurs as a residue ia sulfur distillation or as a precipitate ia molten Frasch sulfur (12,13). Although this material may approach the composition of a carbon sulfide, it is more likely also to contain some chemically bound hydrogen and possibly other elements. Carbon—sulfur surface compounds of the formula C S, where xis greater than 4,... 

FCOJ. Proper reconstitution of FCOJ is essential for valid taste panel results. Since orange juice flavor is of a rather delicate, mild, or light type, the water source used to reconstitute the concentrate must be relatively free of off-flavors, such as sulfurous. Distilled water should be used whenever practical. In addition, if the water used for reconstitution is placed in a refrigerator, walk-in cooler, etc. for chilling, care must be taken to have the water container covered securely to eliminate possible absorption of foreign flavors. And, of course, the reconstituted product itself, if being chilled prior to tasting, should be protected. 

The H-Oil process is a catalytic hydrogenation technique that uses a one-, two-, or three-stage ebullated-bed reactor in which considerable hydrocracking takes place during the reaction. The process is used to upgrade heavy sulfur-containing crude oils, residual stocks, and low-sulfur distillates, thereby reducing fuel oil yield. 

Allegedly, mustard received its name from its smell or taste (onion, garlic, mustard)38 or its color (which varies from yellow, to light tan, to dark brown). When mustard was first used by the Germans, the Allies called it Hun Stoffe (German stuff), abbreviated HS later, it became known as H. Mustard manufactured by the Levinstein process is also known as H it contains about 20% to 30% impurities (mostly sulfur). Distilled, or nearly pure, mus-... 

The "H-COAL" process was developed by Hydrocarbon Research Inc. to convert all types of coal to high octane gasoline, petrochemicals, LPG, low sulfur distillate fuels and low sulfur heavy boiler fuel oil. 

Sulfur in middle distillates is determined using much the same methodology as for gasoline. X-ray fluorescence is the technique of choice. For best results standards should be prepared in a matrix that matches the sample type. A variety of combustion-based approaches are also available, though their applicability to low sulfur distillates may be limited owing to poor sensitivity. 

The residue after sulfur distillation contained all the iron from the pyrite and also much sulfur. It was heaved out onto pot mountains and weathered there for twenty years. In this process two layers were formed - one lower, hard and salty one upper, loose as mold. The lower was iron(ii) sulfate, from which iron vitriol was prepared for use in textile dyeing. The upper layer contained iron oxide hydrate FeOOH, iron ocher, and was the raw material for the manufacture of red ocher paint. During the weathering processes in the pot mountains, sulfur dioxide was evolved, evilsmelling but disinfecting. In periods of plague in the country, prominent persons, such as those from the King s court in Stockholm, arrived at Dylta for protection on or near the pot mountains. 

Between 1850 and 1865, a sulfur distillation plant was built on the side of the volcano, but various attempts to mine sulfur from the crater failed. The highest... 

Strong acid (93 to 103 per cent) used at low temperatures (25 to 50 F) removes sulfur from gasolines, and aromatic hydrocarbons from burning oils or transformer oils, but the color is generally poorer when using fum> ing acid. Cooke and Hayford, in treating pressure distillate by the Stratford centrifuge process, foimd that 80 per cent acid produced a 0.2 per cent sulfur distillate whereas 104 per cent acid reduced the sulfur content to 0.07 per cent. 

Mass spectrometry allows analysis by hydrocarbon family for a variety of petroleum cuts as deep as vacuum distillates since we have seen that the molecules must be vaporized. The study of vacuum residues can be conducted by a method of direct introduction which we will address only briefly because the quantitative aspects are ek r metiy difficult to master. Table 3.6 gives some examples the matrices used differ according to the distillation cut and the chemical content such as the presence or absence of olefins or sulfur. 

Outside of their very high resistance to auto-ignition, the aviation gasolines are characterized by the following specifications vapor pressure between 385 and 490 mbar at 37.8°C, a distillation range (end point less than 170°C), freezing point (-60°C) and sulfur content of less than 500 ppm. 

Influence of the feed coke produced from distillation residue is less structured, less crystalline than that from a cracking residue. If the residue feeding the unit is highly contaminated with sulfur and metals, it is still coke, but is disqualified for certain applications. 

H2S is found with the reservoir gas and dissolved in the crude (< 50 ppm by weight), but it is formed during refining operations such as catalytic cracking, hydrodesulfurization, and thermal cracking or by thermal decomposition of sulfur[Pg.322]

The sulfides are chemically neutral they can have a linear or ring structure. For molecules of equal carbon number, their boiling points are higher than those of mercaptans they constitute the majority of sulfur containing hydrocarbons in the middie distillates (kerosene and gas oil). 

Note that the total sulfur levels are different from those appearing in Table 8.6 as a result of having different distillation ranges. 

Hydrogen chloride released dissolves in water during condensation in the crude oil distillation column overhead or in the condenser, which cause corrosion of materials at these locations. The action of hydrochloric acid is favored and accelerated by the presence of hydrogen sulfide which results in the decomposition of sulfur-containing hydrocarbons this forces the refiner to inject a basic material like ammonia at the point where water condenses in the atmospheric distillation column. 

The different cuts obtained are collected their initial and final distillation temperatures are recorded along with their weights and specific gravities. Other physical characteristics are measured for the light fractions octane number, vapor pressure, molecular weight, PONA, weight per cent sulfur, etc., and, for the heavy fractions, the aniline point, specific gravity, viscosity, sulfur content, and asphaltene content, etc. 

It is possible to calculate the properties of wider cuts given the characteristics of the smaller fractions when these properties are additive in volume, weight or moles. Only the specific gravity, vapor pressure, sulfur content, and aromatics content give this advantage. All others, such as viscosity, flash point, pour point, need to be measured. In this case it is preferable to proceed with a TBP distillation of the wider cuts that correspond with those in an actual refinery whose properties have been measured. 

Vacuum distillation of the atmospheric residue complements primary distillation, enabli r.ecoyery of heavy distillate cuts from atmospheric residue that will un r o further conversion or will serve as lube oil bases. The vacuum residue containing most of the crude contaminants (metals, salts, sediments, sulfur, nitrogen, asphaltenes, Conradson carbon, etc.) is used in asphalt manufacture, for heavy fuel-oil, or for feed for others conversion processes. 

Heavy residues are not always converted. The use of low sulfur light crude and crudes having a reduced ultimate residue (higher ratio of gasoline + distillates/vacuum residue) as well as natural gas utilization has been intensified. 

With brisk stirring 75mL Everclear (ethanol) is poured into the reaction flask then 75mL concentrated sulfuric acid is slowly added until incorporated. The rest of the distillation apparatus is connected and the solution slowly heated to about 140°C. Next, 150mL Everclear is dripped in slowly so as to match the approximate distillation output that one can see condensing over into the collection flask. The temperature must remain between 140-150 C. After all the ethanol has been added (which should have taken approximately 90 min) the distillate that has collected is washed with 5% NaOH solution then with water (remember that the ether will form the top layer here). The ether can then be dried through sodium sulfate and used or can be distilled to purify. 

To a mixture of 25 ml of water and 3 ml of 95% sulfuric acid were added 40 ml of DMSO. The mixture was cooled to 10°C and 0.20 mol of l-ethoxy-l,4-hexadiyne (see Chapter III, Exp. 51) was added with vigorous stirring in 15 min. During this addition, which was exothermic, the temperature of the mixture was kept between 20 and 25 0. After the addition stirring was continued for 30 min at 3S C, then 150 ml of water were added and six extractions with diethyl ether were carried out. The combined extracts were washed with water and dried over magnesium sulfate. Evaporation of the solvent in a water-pump vacuum, followed by distillation through a 25-cm... 

When benzene is prepared from coal tar it is contaminated thiophene from which it cannot be separated by distillation because of very similar boiling points Shaking a mixture of benzene and thiophene with sulfuric acid causes sulfonation of the thiophene ring but leaves benzene untouched The sulfonation product of thiophene dissolves m the sulfuric acid layer from which the benzene layer is separated the benzene layer is then washed with water and distilled Give the structure of the sulfonation product of thiophene... 

Aluminous and siliceous residues A 2% hydrofluoric acid solution followed by concentrated sulfuric acid rinse immediately with distilled water followed by a few milliliters of acetone. Repeat rinsing until all trace of acid is removed. 

This experiment describes a method for determining the acidity, reported as an equivalent molarity of H2SO4, of rain water. Because the volume of standard base needed to titrate a sample of rain water is small, the analysis is done by a standard addition. A 10.00-mL sample of nominally 0.005 M H2SO4 is diluted with 100.0 mL of distilled water and standardized by titrating with 0.0100 M NaOH. A second 10.00-mL sample of the sulfuric acid is mixed with 100.0 mL of rain water and titrated with the same solution of NaOH. The difference between the two equivalence point volumes... 

Polymerization. Paraldehyde, 2,4,6-trimethyl-1,3-5-trioxane [123-63-7] a cycHc trimer of acetaldehyde, is formed when a mineral acid, such as sulfuric, phosphoric, or hydrochloric acid, is added to acetaldehyde (45). Paraldehyde can also be formed continuously by feeding Hquid acetaldehyde at 15—20°C over an acid ion-exchange resin (46). Depolymerization of paraldehyde occurs in the presence of acid catalysts (47) after neutralization with sodium acetate, acetaldehyde and paraldehyde are recovered by distillation. Paraldehyde is a colorless Hquid, boiling at 125.35°C at 101 kPa (1 atm). 

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