Vacuum residue

Crude oil topped at 260°C or atmospheric residue or vacuum residue... 

The distillation continues to a boiling point corresponding an atmospheric boiling point of about 535°C. The remaining material is called vacuum residue. 

Finally, other methods are used to obtain simulated distillation by gas phase chromatography for atmospheric or vacuum residues. For these cases, some of the sample components can not elute and an internal standard is added to the sample in order to obtain this quantity with precision. 

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. 

Feedstock Paraffinic crude Naphthenic crude Vacuum distillate Vacuum residue Deasphalted atmospheric residue... 

Characteristics Atmospheric residue (Arabian light) Vacuum residue (VR) Visbroken residue (on VR) LCO (low sulfur) HCO (low sulfur)... 

Solvent deasphalting. This is an extraction of the heaviest fractions of a vacuum residue or heavy distillate. The extract is used to produce the bitumen. The separation is based on the precipitation of asphaltenes and the dissolution of the oil in an alkane solvent. The solvents employed are butane or propane or a butane-propane mixture. By selecting the proper feedstock and by controlling the deasphalting parameters, notably temperature and pressure, it is possible to obtain different grades of bitumen by this process. 

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. 

Processing Vacuum Residue by Solvent Extraction (Deasphalting) (Biedermann et al., 1987)... 

Deasphalting is a liquid-liquid separation operation that extracts the last of the easily convertible hydrocarbons from the vacuum residue. Solvents enipl ec) are light paraffins propane, butane, and pentane. The yimd In deasphalted oil increases with the molecular weight of the solvent, but its quality decreases. 5 uxct... 

The visbreaking process thermally cracks atmospheric or vacuum residues. Conversion is limited by specifications for marine or Industrial fuel-oil stability and by the formation of coke deposits in equipment such as heaters and exchangers. 

Applied to vacuum residue, its purpose is to reduce the viscosity of the feedstock to a maximum so as to minimize the addition of light diluents for production of fuel-oil for industrial uses. 

The coking process produces electrode quality coke from vacuum residues of good quality (low metal and sulfur contents) or coke for fuel in the case of heavy crude or vacuum residue conversion having high impurity levels. 

Feedstocks are light vacuum distillates and/or heavy ends from crude distillation or heavy vacuum distillates from other conversion processes visbreaking, coking, hydroconversion of atmospheric and vacuum residues, as well as deasphalted oils. 

The residue hydroconversion process applies to both atmospheric and vacuum residues. 

The conversion products, other than gas and hydrogen sulfide (H2S), are essentially a gasoline fraction that, after pretreatment, will be converted by catalytic reforming an average quality distillate fraction to be sent to the gas oil pool and an atmospheric residue or vacuum distillate and vacuum residue whose properties and impurity levels (S, N, Conr. 

Conversions of atmospheric residues are 20 to 35 weight % and 50 to 65% on vacuum residue. 

Feedstock 50/50 vol. % light and heavy Arabian crudes Atm. residue Vacuum residue... 

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. 

Intermediate feedstock preparation processes such as direct hydroconversion of vacuum residues, solvent deasphalting, improved coking will also make their appearance. 

Residues (petroleum), heavy coker and light vacuum Residues (petroleum), catalytic reformer fractionator Residues (petroleum), hydrodesulphurized atmospheric tower Residues (petroleum), topping plant, low sulphur Residues (petroleum), heavy coker gas oil and vacuum gas oil Residues (petroleum), thermal cracked... 

SFC Petroleum wax Atmospheric and vacuum residues Lube oil additives Open tubular FID... 

After cooling, unreacted ethylenediamine is neutralized in a cooling mixture with the absolute ethanolic hydrochloric acid, filtered off from any components that are insoluble in ethanol and approximately two-thirds of the solvent filtered off under suction in a water jet pump vacuum. Residual quantities of ethylenediamine dihydrochloride are precipitated in fractions by the careful addition of ethyl methyl ketone, after which the imidazoline hydrochloride is separated off by the addition of dry ether. Following repeated recrystallization from ethanol ether, 2-[0(-(2,6-dichlorophenoxy)ethyl] -A -imidazoline hydrochloride is obtained in the form of small white crystals melting at 221°C to 223°C. 

Residues containing high levels of heavy metals are not suitable for catalytic cracking units. These feedstocks may be subjected to a demetallization process to reduce their metal contents. For example, the metal content of vacuum residues could be substantially reduced by using a selective organic solvent such as pentane or hexane, which separates the residue into an oil (with a low metal and asphaltene content) and asphalt (with high metal content). Demetallized oils could be processed by direct hydrocatalysis. 

Recycle ratio, vol/vol feed, % Yields Vacuum residue 10-100... 

The teed to the cat cracker in a typical refinery is a blend of gas oils from such operating units as the crude, vacuum, solvent deasphalting, and coker. Some refiners purchase outside FCC feedstocks to keep the FCC feed rate maximized. Other refiners process atmospheric or vacuum residue in their cat crackers. In recent years, the trend has been toward heavier gas oils and residue. Residue is most commonly defined as the fraction of feed that boils above 1,050°F (565 C). Each FCC feed stream has different distillation characteristics. 

Metals, such as nickel, vanadium, and sodium, are present in crude oil. These metals are concentrated in the heavy boiling range of atmospheric bottoms or vacuum residue, unless they are carried over with the gas oil by entrainment. 

Processing residue or purchased feedstocks. Sometimes, the option of processing supplemental feed or other components, such as atmospheric residue, vacuum residue, and lube oil extract, is a means of increasing the yields of higher-value products and reducing the costs of raw material by purchasing less expensive feedstocks. 

The use of RFCC will continue to grow, particularly in regions of the world where atmospheric or vacuum residue contains low levels of contaminants. Careful regenerator and feed injection designs are important in ensuring a successful operation. 

Residue is the residual material from the processing of raw crude (for example, vacuum residue and not vacuum resid). 

Texaco gasification is based on a combination of two process steps, a liquefaction step and an entrained bed gasifier. In the liquefaction step the plastic waste is cracked under relatively mild thermal conditions. This depolymerisation results in a synthetic heavy oil and a gas fraction, which in part is condensable. The noncondensable fraction is used as a fuel in the process. The process is very comparable to the cracking of vacuum residues that originate from oil recycling processes. 

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