Crude oil separator

In an offshore oil production platform, a major accident occurred partly because pump seals failed and therefore an antifoaming agent was not delivered to a crude oil separator. The fact that the pump seals were defective should have been picked up during routine inspections, but the inspections were neglected because of production pressures. The failure to carry out the inspections was a latent error. 

I. C. Callaghan and A. S. Taylor. Fluorosilicone anti-foam additive composition for use in crude oil separation. Patent GB 2234978,1991. 

Table 10-2 gives the composition of a heptanes plus fraction of a crude oil. Separate the components into paraffins, naphthenes, and aromatics. Identify the number of carbon atoms in the paraffins and draw the structure of the naphthenes and aromatics. 

Isomers of ( )-[122]tetramantane, an inherently chiral alkane with a diamondlike cubic framework, were isolated from crude oil, separated, and characterized via X-ray diffraction, IR spectroscopy, ORD, and VCD [270]. The calculated ORD (B3LYP/6-31G(d,p)) is shown in Fig. 27 along with experimental data. Given the size of the basis sets used, and the fact that these alkanes do not have a traditional chromophore with intense valence excitations that can be made responsible for the... 

Fig. 8 Process intensification in water-in-crude oil separation under electric field with or without PHP variation of percentage separation immediately after passing through the electric field in the absence or presence of the sulfonated PHP. Electric field strength of 2.5 kV applied over a distance of 10 cm. (From Ref. l) (View this art in color at www.dekker.com.)...

Figure 8 Concentration of materials in crude oils separated by size-exclusion chromatography. (A) Volume fraction eluted each second (B) moles eluted each second. 1, Arun crude oil 2, North Slope crude oil. (Reprinted with permission Yeung ES (1986) Detectors for Liquid Chromatography. New York Wiley John Wiley Sons, Inc.)...

These compounds are separated into fractions via distillation (separation based on differences in boiling points). The refining of crude oil separates it into many commercial products. 

Knowledge of a crude oil s overall physical and chemical characteristics will determine what kind of initial treatment —associated gas separation and stabilization at the fi ld of production— transport, storage, and of course, price. 

The vapor pressure of a crude oil at the wellhead can reach 20 bar. If it were necessary to store and transport it under these conditions, heavy walled equipment would be required. For that, the pressure is reduced (< 1 bar) by separating the high vapor pressure components using a series of pressure reductions (from one to four flash stages) in equipment called separators , which are in fact simple vessels that allow the separation of the two liquid and vapor phases formed downstream of the pressure reduction point. The different components distribute themselves in the two phases in accordance with equilibrium relationships. 

The water content of crude oils is determined by a standardized method whose procedure is to cause the water to form an azeotrope with an aromatic (generally industrial xylene). Brought to ambient temperature, this azeotrope separates into two phases water and xylene. The volume of water is then measured and compared with the total volume of treated crude. 

The water and sediment contents of crude oils is measured according to the standard methods NF M 07-020, ASTM D 96 and D 1796, which determine the volume of water and sediments separated from the crude by centrifuging in the presence of a solvent (toluene) and of a demulsifylng agent Table 8.13 gives the bottom sediment and water content of a few crude oils. 

Simple conventional refining is based essentially on atmospheric distillation. The residue from the distillation constitutes heavy fuel, the quantity and qualities of which are mainly determined by the crude feedstock available without many ways to improve it. Manufacture of products like asphalt and lubricant bases requires supplementary operations, in particular separation operations and is possible only with a relatively narrow selection of crudes (crudes for lube oils, crudes for asphalts). The distillates are not normally directly usable processing must be done to improve them, either mild treatment such as hydrodesulfurization of middle distillates at low pressure, or deep treatment usually with partial conversion such as catalytic reforming. The conventional refinery thereby has rather limited flexibility and makes products the quality of which is closely linked to the nature of the crude oil used. 

Low Press. Production Separator Crude Oil Stabiliser Vessel Stabilised Crude Oil Pumps... 

Add 23 g. of powdered (or flake ) sodium hydroxide to a solution of 15 ml. (18 g.) of nitrobenzene in 120 ml. of methanol contained in a 250 ml. short-necked bolt-head flask. Fix a reflux water-condenser to the flask and boil the solution on a water-bath for 3 hours, shaking the product vigorously at intervals to ensure thorough mixing. Then fit a bent delivery-tube to the flask, and reverse the condenser for distillation, as in Fig. 59, p. 100, or Fig. 23(D), p. 45). Place the flask in the boiling water-bath (since methanol will not readily distil when heated on a water-bath) and distil off as much methanol as possible. Then pour the residual product with stirring into about 250 ml. of cold water wash out the flask with water, and then acidify the mixture with hydrochloric acid. The crude azoxybenzene separates as a heavy oil, which when thoroughly stirred soon solidifies, particularly if the mixture is cooled in ice-water. 

Place 50 g. of ammonium thiocyanate in a small round-bottomed flask and immerse a thermometer in the substance. Heat in an oil bath until the temperature rises to 170° and maintain it at this temperature for 1 hour. Allow the melt to cool and extract it with 60-70 ml. of hot water. Filter the solution and allow to cool when crude thiourea separates the unchanged ammonium thiocyanate remains in the solution. Filter ofiF the crude product and recrystallise it from a little hot water. The yield of thiourea, m.p. 172°, is 8 g. 

Straight Run Asphalt. In cmde-oil refining, the crude oil at 340—400°C is injected into a fractionating column (5,6,19,20). The lighter fractions are separated as overhead products and the residuum is straight-reduced asphalt. 

Natural Gas Natural gas is a combustible gas that occurs in porous rock of the earth s crust and is found with or near accumulations of crude oil. It may occur alone in separate reservoirs, but more commonly it forms a gas cap entrapped between petroleum and an impervious, capping rock layer in a petroleum reservoir. Under high-pressure conditions, it is mixed with or dissolved in crude oil. Natural gas termed dry has less than 0.013 dmVm (0.1 gaLlOOO fF) of gasoline. Above this amount, it is termed wet. 

Refining crude oil into useful petroleum products can be separated into two phases and a number of supporting operations. The first phase is desalting of crude oil and the subsequent distillation into its various components or "fractions." The second phase is made up of three different types of "downstream" processes combining, breaking, and reshaping. 

Atmospheric Distillation - The desalted crude oil is then heated in a heat exchanger and furnace to about 750°F and fed to a vertical, distillation column at atmospheric pressure where most of the feed is vaporized and separated into its... 

In addition to the distillation of crude oil coming into the refinery, stills of various designs are used in other types of service throughout the refinery. Cracked products are separated in distillation equipment which is very similar to an atmospheric crude pipe still. The principal difference is that these products are hot from the cracking operation, so that a fired heater is not required. 

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