Refining of oil

See also: Refining

The refining of oil indicates the whole of the treatments and transformations aiming at extracting from oil the maximum of products with high commercial value. According to the had aim, in general, these processes are joined together in a refinery. The Raffinerie is the place where one treats oil to extract the marketable fractions.

The Oil, which is a mixture of various bituminous materials, to be usable in the various branches of industry and the combustion engines, must undergo a series of various treatments. Very often, the quality of a crude depends largely on its origin. According to its origin, its color, its Viscosity, its content of Sulfur, its Not of flow, its content of minerals vary. Also, the structure of each refinery must take account of all these factors.

Moreover, one refinery must be conceived to treat a rather broad crude range. Of course, there exist refineries designed to treat only one gross, but they are particular cases where the resource estimated out of crude is rather important.

There exist simple or complex refineries. The simple refineries are only made up of a few treatment units while the complex refineries have some much more.

Indeed, according to the aim had and the place where the refinery is, according to also the nature of the crudes treated (for example gross BTS or HTS, gross Naphténique or Aromatique) the structure of the refinery to build is different; according to also the local potential needs the refinery can be very simple or very complex. Often in Europe, in the United States and generally in areas where the requirements out of fuels are high, the structure of the refineries is complex. On the other hand in the developing countries, this structure is rather simple.

The oil, once arrived at the refinery, is stored in vats of big size. In general one stores oil with low sulfur content (BTS) separated from that with high sulfur content (HTS). It is the same in the treatment. According to the market demand at the moment “, one initially treats you in a cycle with oil BTS before passing in a cycle HTS in order to avoid the pollution of products BTS by those of the HTS. If it is the opposite case, the products resulting from the treatment during a few hours, if it is necessary, are directed towards vats of products HTS to be reprocessed.

Structure of a refinery

Simple refinery

The simple refineries often have a unit of:

Complex refinery

The complex refineries can have, in addition to the units above, other units such as:

  • the catalytic Cracking or (FCC Fluid Catalytic Cracking)
  • the Viscoréducteur ( visbreaking ),
  • the Isomerization,
  • the Polymerization,
  • the Cracking with the vapor or Steam cracking,
  • the Blowing of bitumen.
  • the Coking (coking)

in this case one says that one is in major Conversion (deep conversion). These techniques are employed more and more, because of market evolution: oils available on the market tend to becoming heavier, tandis the request moves towards the " top of the baril" : the market of the heavy fuels is reduced (partly because they are often replaced by the Natural gas) while fuel consumption cars does not cease growing.

Units of refining (Refining units)

We do not claim to give here, in the various treatment units which we will describe, all details on the chemical reactions allowing the transformation of a product into another product, nor strict operating conditions in the operation of these units. The detailed mechanisms of these reactions will make, later, the object of articles separated unnecessarily not to overload the awareness of the oil world.

Distillation

Atmospheric distillation (Topping links)

Atmospheric distillation is a process which consists in separating the fractions from hydrocarbons contained in oil, from/to each other. It is the first stage of the refining, and the very first oil refineries were summarized about with a fractionating column. It is based on the difference of the boiling points of each pure product contained in oil. Indeed each pure hydrocarbon has chemical and physical characteristics specific. For example:

  • methane boils with -161,4 °C,

  • the ethane boils with -88,6 °C,
  • propane boils with -42,2 °C
  • butane boils with -0,6 °C
  • pentane boils with 36,3 °C
  • the hexane boils with 69 °C
It is thus other chemical properties of the pure substances, for example:

the chemical formula:

  • the general formula of these saturated hydrocarbons is CnH2n+2 , formula in which the index N represents the number of carbon atoms contained in the molecule.

  • the general formula of unsaturated hydrocarbons having a double connection is CnH2n , formula in which the index N represents the number of carbon atoms contained in the molecule. Example: the ethylene C2H4 .

  • the general formula of unsaturated hydrocarbons having triple connection is CnH2n-2 , formula in which the index N represents the number of carbon atoms contained in the molecule. Example: the acetylene C2H2 .

The crude oil bought on one of the worldwide markets must answer more or less waiting of the needs for the refiner. This crude oil, as it was known as front, is a mixture of several hundreds of different products, energy of methane to the bituminous residue having different physicochemical characteristics. Such as it is there is hardly utility to have some because it is very right good to be useful in an oil lamp. In order to separate these products between them and to make products really usable of them, one employs physicochemical processes of separation which one calls the refining.

We said in the preceding articles ( to see: Oil ) which there exist all kinds of crudes:

  • paraffinic,
  • naphtenic,
  • aromatic,

who can be:

  • TBTS (very low sulfur content),

  • BTS (low sulfur content),
  • MTS (average sulfur content),
  • HTS (high sulfur content)
  • THTS (very high sulfur content)

and the involved tools (treatment units) are not always adapted to treat all these crudes because with their construction, they are not dimensioned to include all this crude range.

As regards refining, it is not easy to explain the various operations of treatment with simple terms. As far as possible, we try to do it parallel between these operations and those usually used by other industries but it is rare.

The refining consists in initially using the physical characteristics of each component contained in the mixture such as the boiling point to separate them and extract from the primary fractions.

This operation is called distillation. Just like in the home distiller, one heats oil in a closed column which one calls the atmospheric column fractionating and the difference in boiling point of the involved components and the vaporization of the more or less light fractions, one collects at various levels of the column of the fractions of products light, intermediate, average and heavy.

Distillation is known as “atmospheric” because it is done with the environmental pressure in a column provided with a certain number of perforated plates and provided with valves, in general from 30 to 50 plates. After this first distillation, the residual part is sent in another column, less high and comprising less plates than one calls the column of flash distillation .

Indeed, this residual fraction, called “residue atmospheric” contains hydrocarbons with long chains and more the chains are long plus them are fragile, of which likely to be divided into several pieces if the heating continues under the atmospheric pressure.

In order to avoid these inopportune cuts of chains, one makes the separation of the products of this atmospheric residue under a relative vacuum corresponding to a pressure of approximately 40 mm of mercury (the atmospheric pressure corresponds to 760 mm of mercury). This relative vacuum makes it possible to lower the boiling point of the components, therefore these products should less be heated. As it was known as higher, oil is a mixture of hydrocarbons, and atmospheric distillation does not seek to separate the pure substances from/to each other, but only to separate them in fractions. It is also the first stage in the treatment of oil.

Here is more detailed unfolding:

The crude which arrives, passes through a first Train of exchangers to be heated at the good temperature (towards 110 °C), then it is freed of salt if it contains much salt in a unit of “desalting” where, by fresh water addition and from an electrostatic field, this crude is discharged from its salt.

The crude passes then in a second train of exchangers, then a furnace where its temperature is carried to approximately 360 °C. It enters afterwards the first fractionator (atmospheric fractionating column). It is a plate column provided with caps and valves.

As the crude arrives under a high pressure and that the column is under atmospheric pressure, there is a brutal relaxation which one calls “flash” involved products.

This brutal relaxation evaporates out of vapor the light fraction of the crude containing of the light components towards the high part of the column, called “section of correction” . A second fraction, heavier, condenses in the form of liquid and fall to the bottom, into the lower portion of the column known as “section of exhaustion” , at the bottom of the column.

To carry out the exchange of matter, bases of any fractionation by distillation, the ascending vapors must come into circulating contact with the downward liquid fraction to counter-current the column.

To this end, part of the liquid obtained in top of the column by vapor condensation which reaches that point is reinjected in the form of backward flow at the head column. Its progressive vaporization causes the condensation of an appreciably equal number of molecules (of parts) heavier which retrogress towards the immediately lower plates.

In washing thus, by transfer of heat and mass, the ascending vapors, the liquid going down grows rich by all the heavy components. The vapor phase which goes up towards the higher plates absorbs on the contrary all the light components and the concentration of those is increasingly large in this phase.

It is established kind in the column, from top to bottom, an increasing variation in temperature since this one rises with 110 °C in top of column to reach 350 °C in bottom of column. The exchange of matters between vapor and liquid what is called constitutes the Taux of backward flow .

More the “rate of backward flow” is high, better is the separation of the various products. This rate turns in general around 7 in the atmospheric column.

By the side rackings, placed at the good places throughout the height of the column, one at the head collects column the lightest fraction containing liquid gases and naphtha, then a little low of the kerosene, gas oil light, gas oils means and heavy and finally of the atmospheric residue.

The laterally tapped fractions are subjected, moreover, with a complementary fractionation called “stripping” in called additional columns “strippers”, in order to eliminate the still dissolved light fractions. This is done by steam injection, with counter-current.

The residue can be used directly in the manufacture of commercial heavy fuels or undergoes a new distillation called distillation under-vacuum.

Of course, all these fractions which one has just tapped with the atmospheric fractionating column result from a primary separation and all will be used as loads (to some extent like raw materials) ( feedstock ) to feed from other treatment units of the refinery.

The cylindrical form, fractionating column itself, consists of perforated plates of holes and provided with caps and valves. These plates are placed the ones with the top of the others. In general, the number of plates is of forty (between 30 and 50 depend on the crude range which one wants to treat with it). The column has an entry which is located a little at the top of the bottom of the column for the arrival of the crude to treat. In addition, this column comprises various exits (or rackings ) to extract the various products during distillation.

The site of the entry of the crude as well as the site of the exits of the fractions are not randomly made, but are calculated so as to be able to treat a crude range of various qualities.

For rackings of products, at the head of the column, one finds the launch of gases and the light products which form the cut total naphtha. On the side of the column, and from top to bottom one finds racking:

  • of the kerosene,
  • of the light gas oil,
  • of the average gas oil,
  • of the heavy gas oil

and in bottom of column the exit

  • of the atmospheric residue.

After this pretreatment, all the tapped fractions will be used as loads (feedstocks) to feed the other treatment units downstream. We will examine these units on the basis of the fraction lightest i.e. that tapped at the head atmospheric fractionating column.

Treatment of the fraction naphtha (Naphtha treatment)

Hydro-treating (Hydrotreating)

The naphtha fraction, left at the head column contains a mixture of all gases and total naphtha (final point (PF) of boiling 180 °C, or 150 °C if the requirements in kéro are high). Before making separation in various small fractions, one will pass this naphtha in a unit of hydro-treating in order to remove all the sulfur which it contains.

This unit consists of a loop conveying of the hydrogen, pressurized by a compressor, through an engine containing a catalyst. This one facilitates the transformation of the sulfur compounds into H2S, easier to evacuate. The reaction being consuming hydrogen, a supplement is made permanently, in general since the unit of catalytic, producing reforming of hydrogen. The gasoline and formed H2S are separate in successive separating balloons, in which one will tap a gas rich in hydrogen returned in the loop and a gasoline rich in H2S. The gasoline is then strippé: it is thus removed from H2S which is evacuated at the head of the strippor, in the form of acid gases treaties in the units of amines.

This reactional concept of loop is identical for the units of gas oil HDS.

Indeed, sulfur is a very corrosive product and the catalysts contained in other units will be destroyed and become inactive in the passing of the sulfur products. In addition, the other commercial products extracted from this naphtha such as propane, butane should not either contain sulfur or sulfur compounds.

Also, before splitting this naphtha in narrower cuts, one removes the sulfur, contained in this fraction, by making it combine with hydrogen to form hydrogen sulfide of H2S formula, which leaves towards a Claus unit to make liquid sulfur of it. One can also keep the cut total naphtha such as it is without making new fractionations and to use it like charges for the cracker with the vapor.

Hydrogen used comes from the catalytic unit of reforming.

Naphtha stabilizer (naphtha stabilizer)

The fraction of total naphtha resulting from the hydro-treating and removed from its sulfur is sent like charges in a stabilizer (or fractionator). This column functions with a rate of backward flow very high under a pressure of about 5 to 10 bars in order to eliminate all gases and to adjust the vapor tension of the cut naphtha. To the exit of this unit, all the gases C4- (i.e. butane and all gases lighter than this one) are sent towards the “gas seedling” to be treated.

In the stabilizer (still called debutanizer ) the naphtha which remainder is separate in two fractions: the light naphtha and the heavy naphtha . The first has a final point of distillation of 80 °C (or of 100 °C) and the last can have a final point of distillation of 150 °C or 180°C according to whether one seeks to have a short kéro or a long kéro.

Indeed if one needs to manufacture a great quantity of kerosene, in this case, one cuts naphtha to 150 °C, in the contrary case, one fixes the final point of distillation at 180 °C and sometimes even with 185-190 °C.

The light naphtha is sent to storage as bases of mixture (or English blendstock) to be used later in the manufacture of the fuels.

The heavy naphtha is sent then in load (feedstock) to feed the unit of “catalytic reforming”

It should be announced here that the naphtas light, heavy and total stabilized can also be sent in load (liquid or vapor) to the vapocraquor.

Treatment of the cut kerosene (Kero treatment)

Hydro-treating (Hydrotreating)

According to the needs for the moment, the refiner can fix the initial point of cut of the kerosene with 150 °C or 180 °C. The final point of distillation of this cut is in general of 225 °C but can also go up to 250 °C. If this cut is resulting from a crude TBTS (Very Low Sulfur Content), it is useless to treat it. If it is resulting from a crude containing of sulfur, one sends this cut towards the unit of hydro-treating in order to remove all sulfur that this one contains. This one, in the presence of hydrogen, will form hydrogen sulfide which will be sent towards the network of gas Riche in H2S and envoy in load of a unit Claus (Safeguard of the environment).

Treatment of softening (ex: Merox Links)

Another process to eliminate the sulphuretted products contained in the kerosene is the treatment in a unit of softening (sweetening) as for example MEROX (MEROX is the name of a process to soda). This process is used only for cuts containing few products sulphuretted particularly mercaptans. In this process, contrary to the hydro-treating, one does not eliminate the sulfur contained in the cut but one makes it complex . Indeed one transforms the corrosive mercaptans into noncorrosive disulfides. Those are not eliminated and remain in the cut but do not have any more aggressiveness. The extractive MEROX, alternative of process MEROX, make it possible to eliminate formed disulfides.

The kerosene, removed from its sulfur, is sent to storage to be used in the manufacture of the JET A-1, carburizing for the planes.

The technical specifications of the JET A-1 are rather severe in particular from the point of view congelation, a little less on the level of the sulfur content of the product. The international standards for the freezing point of the JET A-1 are of -47 °C. Indeed, to 11.000 meters of altitude, the outside temperature can go down up to -65 °C, and one easily imagines the consequences for a plane if the fuel froze in the tanks!

Hydrodesulfurization of the cuts gas oil (Hydrodesulfurization)

Gas oil (light or average) resulting from atmospheric distillation, if it comes from a rough TBTS is sent such as it is to the storage of intermediate products which will be used for the various mixtures.

On the other hand, if it is resulting from a sulfurous crude (MTS or HTS), it must pass like charges with hydrodesulfurization to desulphurize it. As in the hydro-treating, hydrodesulfurization is a treatment hydrogen in the presence of catalyst in order to transform the sulfur contained in the gas oil into hydrogen sulfide (H2S) and this gas is sent in a unit of absorption to the amines. In this one, H2S is washed with the DEA in an absorber. The washed gas is sent to the network fuel-gas of the refinery, the DEA charged in H2S is treated in a regenerator: it is distilled there, H2S is recovered at the head column. It is sent towards a " machine with soufre" , based on the Claus process to make liquid sulfur of it. Let us note that the hardening of the legislation concerning the rejections with the atmosphere involves the installation of an additional treatment downstream from the sulfur factories, the TGT (treatment of gases of tail), which still look further into the conversion of H2S and improve quality of the rejections.

Distillation under-vacuum (Vacuum Links)

In bottom of atmospheric fractionating column, there remains a residue whose initial point is of 380 °C (sometimes pi is of 390-400 °C). As it was known as at the beginning, all the objective of the refining is directed towards the transformation, by various processes, hydrocarbon components with long chains in components with short chains containing a number of carbon, if possible, in the surroundings of C8 - C10 . This to have the maximum of light fractions with high commercial values.

In the United States, the majority of the refineries have this objective, to manufacture the maximum of gasoline and Jet A1, because the market needs American of these two products are enormous.

Thus the flash distillation is a first stage tending to going towards this objective.

The atmospheric residue is sent like charges at the entry with the vacuum column. Indeed, all the hydrocarbon components which cannot be tapped in the atmospheric column, without undergoing a thermal phenomenon of Craquage, because of their too high point of boiling to the atmospheric pressure, are distilled here under a relative vacuum. The vacuum column is only made up from 8 to 20 plates or garnishing (or an alternation of both), functioning under a pressure of about 40 mm of Hg (mercury) (the atmospheric pressure is equal to 760 mm of Hg).

Here the vaporization of the load is supported by a steam injection and the vacuum is carried out using a series of ejectors with vapor.

Therefore, one can tap at the exit of the vacuum column of:

  • Gas oil under-vacuum,

  • light Distillate under-vacuum,
  • heavy Distillate under-vacuum,
  • Residue under-vacuum.

The first two fractions can be used as complements in the various mixtures of end products, but also like loads for a catalytic unit of cracking (e.g.: the FCC ( Fluid Catalytic Cracking )). As for the residue under-vacuum it will be used as load to the viscoreductor. Here it should be also announced that one can also send the atmospheric residue as charges with viscoreductor if this one is too viscous.

Conversion

Alkylation

Alkylation is an operation which makes the synthesis of paraffins ramified starting from isobutane and light olefins to have fuel components with high octane number. It is the opposite operation of a cracking. The reaction is made in liquid phase in the presence of a catalyst which can be sulphuric acid ( SO4H2 ) or hydrofluoric Acid ( FH ). The compound obtained is indicated under the name dalkylat in the oil jargon and which enters the composition of the gasolines.

Isomerization (Isomerization)

Isomerization is an operation which makes it possible to transform a linear paraffin into isomer paraffin with an aim of increasing its octane number. The load of a unit of isomerization is light naphtha (C5-C6). The compound obtained is indicated under the name disomérat in the oil jargon, and which enters the composition of the gasolines.

See the Leitartikel on the chemical reactions of isomerization: Isomerism

Catalytic reforming (Catalytic Reforming or Cat Reforming)

The catalytic reforming aims to transform the naphtenic components into aromatic components with top Number octane as a basis being used for the mixture of the gasolines. The unit of reforming is primarily made up of a series of three engines containing of catalyst and a fractionator being used to separate the various products at the exit from the engines. This catalyst is very sensitive to the presence of sulphuretted and nitrogenized products, also the load of reforming must be of sulfur, nitrogen and their derivatives.

The reaction occurs under high pressure and at high temperature of about 550 °C with production from hydrogen coming from the naphtenic molecules. It is an endothermic reaction. Indeed, the connections in the naphtenic molecules open and release from hydrogen and these molecules give rise to aromatic molecules whose leader is the Benzène. The benzene is an aromatic hydrocarbon which is appeared as a hexagon having 3 double connections whose chemical formula is C6H6 .

In the unit it is by dehydrogenation partial of cyclohexane ( C6H12 ) that one obtains benzene. Opposite the representation of the general reaction of dehydrogenation in the engines in the presence of catalyst.

The load of the unit can come from various units such as the heavy naphtha of atmospheric distillation after passage to the hydro-treating or of the hydrocracker.

On the outlet side of the fractionator one finds the products following:

  • Hydrogen
  • Fuel gas
  • Cut Propane/Butane
  • Cut pentane
  • Reformat, which uses the composition of the gasolines

Hydrogen is used for the hydro-treating and hydrodesulfurization, Fuel gas is sent to the network fuel gas, Cut C3/C4 is sent in load towards the gas seedling, The cut pentane as well as the reformat are sent to storage to be used as a basis for the mixtures of fuels.

Catalytic cracking in fluid bed ( Catalytic Cracking or Cat Cracking )

Catalytic cracking in fluid bed is a process of refining the purpose of which is to transform, in the presence of a catalyst, the heavy cuts with long carbohydrate chains out of light cuts to be used in the manufacture of the fuel. As always, the objective is to have the maximum of products with high commercial value.

In the presence of catalyst, high temperature (450 to 550 °C) and with atmospheric pressure, one breakage large hydrocarbon molecules to have small molecules having a high octane number.

The first catalysts were consisted thealuminated ones whose acid character activates the rupture of the bonds between the carbon atoms. These catalysts were improved by incorporation of the molecular sieves and rare earths. Thus the operations of cracking can be led to less high temperatures under normal pressure. The deposits of coke constitutes a principal technological problem to solve because it imposes a permanent regeneration of catalyst.

The industrial process often used, comes from the United States, it is “FCC” (1) or “Fluid Catalytic Cracking” . It is based on the use of a fluid catalyst bed. The catalyst, of a size of some 50 micrometers approximately, is in suspension in the load, which, after pre-heating, is injected into the engine in gas form.

The effluents, removed from the catalyst drives by means of a “cyclone” , are sent in the fractionator. Here in this process, the catalyst runs out in a continuous way, towards the regenerator in which the air for combustion is puffed up, then turns over to the engine. For this reason one calls Fluid Catalytic Cracking

The loads which feed the FCC come from the flash distillation, they are the distillates light and heavy under-vacuum. After passage of the loads in the engines, the whole of the products resulting passes in a fractionator and at the exit one can collect the following products:

  • the fuel gas which is directed towards the network fuel gas,

  • the cut C3/C4 which will be treated with the gas seedling, this cut contains much olefin such as butadiene and butylenes.
  • the total gasoline of FCC which, after desulphurization, will be used in the manufacture of the fuels,
  • the light gas oil of FCC will be used to manufacture the driving gas oil or the gas oil of heating,
  • the heavy gas oil of FCC will be used in the manufacture of the fuel.

(1) Registered trade name , therefore nontranslatable in French

From the cracked gases which contain much olefin, one can, by alkylation (polymerization), to carry out the gasoline synthesis with high octane number.

Hydrocraquage (Hydrocracking)

The hydrocraquage is a process making it possible to convert heavy oil Distillates into light cuts with high commercial value. This process is implemented under a strong temperature of order 250 to 450 °C and a strong hydrogen pressure (between 50 and 150 bars), in the presence of a fixed-bed catalyst.

At this temperature, there are cracking of the long molecules and appearance of the olefinic molecules. But in the presence of hydrogen under high pressure, there is hydrogenation partial of these olefins and also of aromatic formed. Heavy intermediaries are at the origin of the formation of coke. It is necessary to also announce that with this process, the hydrogen consumption is rather important, about 200 to 700 m ³ of H2/m3 of load.

The industrial process often used comes from the USA, it is the hydrocraquor of Rafter.

The loads used in this process are light and heavy distillates under-vacuum as well as heavy distillate of viscoreductor.

Differences between catalytic Cracking in fluid bed and Hydrocraquage. Catalytic Cracking in fluid bed withdraws carbon with the cracked load and gives mainly gasolines and olefins (propylene, butylene) which interest chemistry. The hydrocraquage adds hydrogen to the cracked load all while desulphurizing it and gives mainly gazoil for the diesel and of the kerozene for the planes.

The hydrocraquor indirectly emits gases with greenhouse effect during manufacture of hydrogen starting from natural gas in a Steam Methane Reforming . Catalytic Cracking in fluid bed emits gases with greenhouse effect during regeneration of catalyst by combustion of the coke deposited on this last.

Catalytic Cracking in fluid bed uses a catalyst reads some circulating whereas Hydrocraqueur works fixed-bed.

The hydrocraquor must be stopped to renew catalyst contrary to catalytic Cracking in fluid bed.

Contrary to the hydrocraquor, the mode of use of a catalyst in bed circulating in catalytic Cracking makes it possible this catalyst to be regenerated and makes it possible catalytic Cracking in fluid bed to make major conversion by developing Atmospheric Residues, name given to the bottom of turn not vaporized of atmospheric distillations.

The effluents resulting from the unit and after fractionation are:

  • fuel gas directed towards the fuel gas network,
  • cut C3/C4; this cut contains a good quantity of olefin (butadiene and butylenes),
  • light naphtha being used with the mixtures as fuels,
  • the heavy naphtha used like charges with reformor,
  • the kerosene for pool kéro,
  • the gas oil for pool gas oil,
  • the residue for pool fuel.

Viscoréduction (Visbreaking)

As always, here one seeks to transform the residues into light cuts to have a better valorization. In order to reduce the viscosity of the heavy cuts and the viscous residues, one uses a process called viscoréduction (visbreaking) the purpose of which is to partly transform the heavy products into light products and to reduce the viscosity of the residue at the same time. Indeed, it is a " cracking thermique" of atmospheric residue or under-vacuum, with severity, in general, moderate. The various processes of visbreaking operate in liquid phase between 450 and 500 °C under a pressure ranging between 5 and 20 bars.

The loads which feed this unit of refining come from distillations atmospheric and under-vacuum and of catalytic cracking, it is:

  • the atmospheric residue,
  • the residue under-vacuum,
  • heavy gas oil of FCC.

At the exit of the unit, one finds a whole product range following:

  • fuel gas (is sent to the network fuel gas)
  • cut C3/C4 (is directed towards the gas seedling)
  • wild gasoline of visbreaking (is directed towards the HDT (hydro-treating))
  • light distillate of visbreaking (is sent to hydrodesulfurization)
  • heavy distillate of visbreaking (is sent in load towards the hydrocraquor)
  • the residue of visbreaking (is sent to the pool of fuel or bitumen).

Blowing of the bitumens (Asphalt blowing)

The bitumen is a product which adheres in the majority of usual materials: hone, concrete, wood, cement, metal, glass, etc It is an excellent heat insulator, dielectric and phonic and it is flexible. The bitumen is presented in a viscous form, in fact more or less viscoelastic of black color. It is composed of a mixture of hydrocarbons of raised molecular weight, which belongs to the three following groups:

  • paraffinic,
  • naphtenic,
  • aromatic.

In general, the bitumen consists of 80 to 85% of carbon and 10 to hydrogen 15%. It is made of two parts of which one is insoluble (the Asphaltènes) and the other soluble one (the Maltènes).

The bitumen is presented in the form of a colloidal system. But if there are sufficient aromatic molecules in the part maltenes , asphaltenes can then be flocculates. This system can be regarded as a " gel" which confers on the bitumen its elastic properties. It is in particular the case of the bitumens known as " soufflés" or " oxydés" .

The bitumen left such as it is the units of refining is too soft to be used for the road coatings. Also to make it harder, one carries out his blowing. The process is neither more nor less one dehydrogenation partial and a polymerization of the bitumen with oxygen in air.

Indeed, while making pass the air through the bitumen under high temperature (240 to 260 °C), there is partial dehydrogenation and the oxygen contained in the puffed up air forms bridges oxygenates with the hydrocarbon chains and it is formed three-dimensional networks by polymerization. The reaction is more or less exothermic and the temperature in the tower of blowing never exceeds 300°C under penalty of appearance of the phenomenon of " craquage". The hardness of the bitumen obtained can be controlled by the time of passage of the air, because more there are bridges oxygenates harder is the bitumen.

Thus one obtains more or less hard bitumens according to the market needs. The hardness of the bitumen is defined by their penetrability (1) minimal and maximum. The harder the values of penetrability are small, is the bitumen. The official specifications envisage 5 qualities:

  • 20/30 hardest,
  • 40/50,
  • 60/70,
  • 80/100,
  • 180/220

These bitumens are especially used in the construction and the maintenance of the roadways, in hydraulic work, and industry (paper mill, sealing).

(1) the " pénétrabilité" is defined and is expressed by the depth in 1/10 mm to which a vertical needle in a matter sample under operating conditions well penetrates defined of:

    • load = 100 gr.,
    • time = 5 seconds,
    • temperature = 25 °C.

The rough with bitumen are heavy crudes coming from Venezuela (Boscan, Bachaquero, Lagunillas and Tia Juana) or from the Middle-East (Safaniya (or heavy Arab) and Kuwait).

Additional units

Gas Seedling

In order to separate propane from butane and fuel gas, all the C3/C4 cuts coming from the other treatment units pass by the gas seedling. The gas seedling is quite simply a fractionator. The loads can come from:

  • catalytic Reformeur,
  • stabilizing Naphtha,
  • Fluid catalytic cracking (FCC),
  • Viscoréducteur,
  • Hydrocraqueur,
  • Craqueur with the vapor.

At the exit of the gas seedling one finds oneself with:

  • fuel gas (which is sent to the network fuel gas),
  • propane (which is sent to the storage),
  • butane (which is sent to storage and which will be used partially for the mixture of fuels).

To eliminate the mercaptans contained in liquefied petroleum gases (LPG), one makes use of the molecular sieves which are then regenerated, by passage to against current, on heated hydrogen.

Treatment the amines

For the gas cleaning of refinery, in order to remove the sulfur compounds (at the origin of the bad smells) and in particular H2S, poison, one subjects to these gases a treatment the amines. The process is based on the chemical absorption of the hydrogen sulfide in an aqueous solution containing of diethanolamine. Then, by heating, one eliminates the hydrogen sulfide and one thus regenerates the active aqueous solution which one reinjects in the absorber.

This process is also used to purify the hydrogen of recycles units of hydro-treating to thus increase by it the pressure partial of hydrogen.

Petrochemistry

Vapocraquage (Steam cracking)

This process of refining is rather a process used in Pétrochimie, but the refiner benefits from it to recover under products such as C3, C4, C5 and the raffinat to be used in the composition of the fuels.

Indeed, the objective of this process is to produce ethylene ( C2H4 ) and Propylène ( C3H6 ) which are bases in the manufacture of the Polyéthylène and of the Polypropylène by polymerization.

The load used is naphtha coming from the refinery or bought outside.

A vapocraquor is a unit of petrochemistry being used to manufacture ethylene and propylene two products essential in the manufacture of polyethylene and polypropylene, two known plastics.

As we said previously, in the oil industry one always seeks to maximize the production of the matters with high commercial value and the fact of breaking the long chains to obtain shorter chains is a useful and advantageous objective.

It should be noted that the ethylene and the propylene exist only seldom in great quantities in nature because nature does not like the unstable states. Indeed, in term of chemistry one says that these products are Insaturés i.e. the connections being used to connect the atoms of carbon (or coal in simple term) between them are double, some carbon atoms contained are not connected to a sufficient number of hydrogen atoms.

As these products are “unsaturated” by nature, and like nature horror of the vacuum has (the absence of hydrogen atom leaves a “vacuum (atomic)” in these products), they tend to be saturated while collecting is other atoms of hydrogen or of the atoms of oxygen and for this reason it is not frequent to find them in nature.

The petrochemical operation consists in taking a cut heavy naphtha containing of saturated hydrocarbons having long hydrocarbon chains (attention all is relative, previously we spoke about long chains for the gas oils and the residues, those have chains of several tens of carbon atoms. Here the number of carbon atoms does not exceed ten).

The unit functions at very high temperature and low pressure. One introduces this cut naphtha into the vapocraquor who has a series of engines. Inside this unit reigns a very high temperature, about 500 °C with 600 °C and in the presence of the steam (about 50/50 in weight) which reduces the “time of residence” and avoids the coke formation. Under these conditions, the hydrocarbon molecules of naphtha are divided into several pieces giving rise to liquid gases, ethylene, propylene, butadiene, isobutylene and other products unsaturated as well as a cut called “raffinat” used like component of the fuels.

According to the quality of naphtha, one obtains outputs (productions) of more or less high ethylene and propylene. Indeed, to have good propylene and ethylene yields, it is recommended to have “paraffinic” loads well because the structure of these two products are paraffinic chains. As it was known as in the preceding articles (see Pétrole), an oil can be paraffinic (contain many paraffins, chains linear without cycle), naphtenic (cycles with simple connections), or aromatic (cycles with double connection).

To have an idea, at the exit of the unit, there is an output of about 25% to ethylene 30%, of propylene 15%, the remainder is consisted methane, gasoline rich in aromatic and of C4 sent towards the unit of extraction of the aromatic ones.

Naphtha is not the only load feeding a vapocraquor. Any molecule relatively long and likely to be divided into several fragments is good to be “cracked”. Thus one can also use gas oils and distillates like some aromatic compounds like loads.

The ethylene resulting from the vapocraquage is used in the manufacture of ethanol and, (VC) ethylbenzene, vinyl chloride ethylene oxide. To summarize let us see a little the diagram in the sequence of the birth of the new products starting from ethylene:

The products resulting from the C2H4 ethylene are

  • of the Chloride vinyl

  • of the ethylbenzene
  • of ethylene the Oxide
  • of the ethanol (or ethanol)
  • of polyethylene

With vinyl chloride one frabric:

  • of the polychloride of vinyl which gives:
  • of the plastics.

Ethylbenzene gives two products: Styrene and Rubber SBR.

Styrene one transforms it by polymerization:

Rubber SBR one obtains:

  • of rubber resins

Ethylene oxide ( (CH2) 2O ) (very explosive because assoiffé of oxygen) gives:

  • of the ethylene glycol which itself, combined with:
  • the Terephtalic acid which gives:
  • of the polyester fibers,

The ethanol gives directly:

  • of the solvent

Polyethylene gives directly:

  • of plastic films

The ethylene oxide ( (CH2) 2O ) is a very unstable product because of “the non-saturation” of its chemical structure and explodes immediately in the presence of oxygen, i.e. he seeks to fill the atomic vacuum of his structure by collecting the oxygen atoms in air. In 1957, an ethylene oxide master engine exploded in Antwerp (Belgium) making several deaths and the soufflé of the explosion moved a mass spectrometer (of more than one hundred tons) several tens of meters. The ethylene glycol is also useful in manufacture of antifreezes.

It is the same for propylene except that the diagram is packed more because this one contains a carbon atom moreover. The propylene resulting from the vapocraquor will give rise to certain a number of other new products.

The products resulting from the C3H6 propylene are

Acrylonitrile one draws:

Isopropanol one manufactures:

  • of solvents,

From propylene oxide one manufactures:

  • of the Polyurethane which gives:
  • of the plastics,

Propylene-glycol one can manufacture:

  • of the Toluene di-isocyanate (TDI) which, itself, gives:
  • of the Polyether S which gives to the end:
  • of the detergents.

Alcohol oxo one draws from the phtalic anhydride which, itself gives:

  • of plasticizers.

We will not describe here all the chains of new products resulting from the effluents at the exit of the vapocraquor such as butadiene, isobutylene, normal butylene and isoprene (see further: Extraction of aromatic). Of course these last four generate themselves of tens of other products used in industry as elastomers, plasticizers or adhesives.

Obviously, all manufacture of these new products requires the presence of petrochemistry, of the varied petrochemical units, the reactions with other components which it is too complex to explain in a simple way.

Polymerization (Polymerization)

Generally, the Polymérisation is a process which makes it possible to build, starting from the bases liquid or gas, of the three-dimensional networks giving of the multi-purpose plastics (Plastomère S).

Thus starting from ethylene or of propylene, one manufactures polyethylene or polypropylene, which are what is called Polymère S , plastic used in the form of film. Polymerization is done in the presence of catalyst which initiates the reaction.

In the oil industry, it is rather a process of " Petrochemistry ".

In the refining, one can also carry out a polymerization of the products in C4 in order to obtain a product with high octane number, but in this case there is a polymerisate .

Extraction of aromatic (Aromatics Extraction)

The C4 cut and the gasolines coming from other units (cracking with the vapor, FCC, hydrocraquage) and after hydro-treating, are rich in aromatic products such as:

  • the Cumène,

  • the Benzene,
  • the Toluene,
  • the Orthoxylene,
  • the Paraxylene.

By processes of extraction, using solvents like the diméthylsulfoxide and butane for example, one recovers these products which one treat then, very often by oxidation and/or hydrogenation, to obtain:

  • of the Nylon 6 and the Nylon 6.6,

  • of the Detergent S,
  • of the Plasticizer S,
  • of the Insecticidal S,
  • of the plastic S,
  • of the resins and
  • of the polyester fibers.

Products resulting from the cumene C6H5CH (CH3) 2

Thus the cumene, by oxidation gives:

Cyclohexanol gives on the one hand Adipic acid and on the other hand Cyclohexanone:

  • the adipic acid gives Hexaméthylène diamine which, combined together gives:

    • of Nylon 6.6

The phenoplasts give directly:

  • of the plastics.

The nonylphénol gives with the Polyéther:

  • of the detergents

Products resulting from the C6H6 benzene

The benzene can generate, after various reactions:

One obtains, starting from the maleic anhydride of plasticizers.

The ethylbenzene gives

  • styrene bases, which itself, by polymerization gives
    • polystyrene which is:
      • of the plastic.

The cyclohexane gives

The alkylbenzene by reaction with sulphuric Acid ( SO4H2 ) generates:

  • of the detergents

The chlorobenzene produced:

  • of the insecticides

the diphényl produced:

  • of the Dowtherm

Products resulting from C6H5CH3 toluene

From toluene one can obtain:

  • of the phenol by oxidation

  • of the Toluene di-isocyanate
  • of solvent directly.

The toluene di-isocyanate combined with propylene glycol gives:

  • of the Polyuréthane S which are plastics

Products resulting from orthoxylene C6H4 (CH3) 2

  • Note:: in developed formula, orthoxylene has the two radicals CH3 side by side on two contiguous tops of the hexagon.

The Orthoxylene, by oxidation, provides:

  • of the phtalic Anhydride which can react with alcohols in C8 to give:
    • of the plasticizers
  • the same phtalic anhydride can combine with the Diol S to give birth:
    • with the resins.

Products resulting from paraxylene C6H4 (CH3) 2

  • Note:: in developed formula, paraxylene has the two radicals CH3 on two opposite tops of the hexagon.

The Paraxylene, by oxidation, gives:

  • of the Terephtalic acid which, combined with ethylene oxide gives birth:

Units of mixtures (Blending units)

The mixtures (Blending)

The intermediate products resulting from the units of refining are seldom commercial products (except the naphtas and some other products) and cannot be sold such as they are. To be marketable, those are mixed in variable proportions according to the technical specifications of the end products. These technical specifications can be national or international specifications and obey precise definitions based on standards (ASTM, NF and IP).

For the national specifications, (at least in France) those are enacted by the Ministry for Finances and the Management of the Fuels (Ministry for Industry) of the country, while the international specifications are subjected to standards enacted by the international organizations. As for the products used by the army, the army of each country has its own requirements.

Thus for certain countries, one uses only fuels without lead while for other countries one continues to put lead tétra-éthyl (PTE). It is the same for the other products, gas oil without sulfur, or with little sulfur.

In refinery, to make mixtures, one uses dosing apparatuses with automatic check which one posts for each product entering the final composition, the percentages fixed in advance. Once the mixture is made, one carries out an analysis at the laboratory in order to stick to more close with the awaited specifications. Very often, in order to save the components and/or the additives, these specifications are respected but with properties slightly lower than the standards.

At the exit of the units of mixtures, one finds a whole product range marketable whose pricipaux products are the following:

  • of propane
  • of butane,
  • of light naphtha,
  • of heavy naphtha,
  • of the fuel car,
  • of high-grade petrol,
  • of the kerosene,
  • of the Jet A1,
  • of the driving gas oil,
  • of the gas oil of heating,
  • of the gas oil marinades,
  • fuel BTS,
  • of the fuel MTS,
  • of the fuel HTS,
  • of the bitumen of various hardnesses

there exists also fuel gases and combustible fioule used by the refinery itself.

The lubricants (Lubricants or Lube oils)

Concurrently to these quoted products, it is necessary to also announce the existence of a class of very advantageous products for the refiner: it is the class of the lubricants. The lubricants have as a crucial role to reduce friction between two metal bodies, but their functions extend much more:

  • To reduce frictions,

  • To fight the premature wear of the bodies and the parts moving in the machines,
  • To take part in thermal balance by absorbing part of the produced calories,
  • To contribute, by their fluidity, with the sealing with gases and the liquids,
  • To eliminate the impurities produced by the machines allowing to prolong the life of those.

To obtain basic oils from which one manufactures oils finies' for engines, one takes the atmospheric residue which one passes to distillation under-vacuum. Then one makes undergo a whole series of treatments as follows:

  • distillation under-vacuum --> residue under-vacuum,

  • de-asphalting with propane,
  • treatment the Furfuryl alcohol (or another selective solvent) to extract the aromatic ones,
  • treatment the Methyl-éthyl-ketone (MEK) (or another selective solvent) to extract paraffins and waxes,
  • finishing treatments:
    • hydrofinissage,
    • clarification of oils,
    • stabilization of oils.

With these basic oils one adds various additives to manufacture finished oils for engines. Here the addition of additives is not used as arguments of publicity or sale, but meets needs for precise functions during the use of oils. It is necessary thus to keep in the spirit that here, exceptionally, the additives meet real needs of performance. These additions are the results of long research to the labotatoires.

Without going into the details, it should be known that there are three lubricant big classes:

  • oils and greases for spark-ignition engines,
  • oils and greases for industry,
  • oils and greases marine.

It is thanks to the lubricants that a mark can be distinguished from another mark and attract new customers. Thus it is by this way that a mark can build its reputation and keep faithful customers in spite of competition.

Technical specifications of the products (Products specifications)

The products, once mixed starting from the bases (or blendstocks), are marketable. But those must have technical specifications (physical and chemical) corresponding to the standards enacted by the Law, or by the profession itself. For certain products, in order to keep an good image of mark of these products, the oil company itself can manufacture products exceeding some little the enacted standards, by adding various additional additives.

It is thus normal that each marketable product has physical and chemical characteristics which are clean for him. But in the manufacture of the products, the refiner is unable to respect, with the letter, these characteristics. Also, instead of fixing values for those, one creates minimal and maximum limits for each one of these characteristics.

As the oil industry is, for all the countries, without any exception, an enormous financial manna, here like elsewhere, one creates several stages in the specifications in order to be able to put taxes and taxes of all the kinds.

In France, initially, one considers that any oil product is a produced importation . Thus there is a first category of specifications which one calls " specifications douanières." . Then there is a whole series of other specifications whose complete listing follows:

  • customs Specifications ,

  • administrative Specifications ,
  • inter-union Specifications ,
  • internal Specifications ,
  • particular Specifications .

Without wanting to go too much into the details of these specifications which interest only the specialists concerned, let us say that the first two categories allow at the state to take a whole series of taxes and taxes, the third category relates to the profession itself, fourth is made for the brand image of the oil company itself and the last makes it possible the companies particularly to look after their important customers .

It should be also announced that for the products delivered to the army of the country, this one can define (and require) particular specifications.

One sees that there does not exist, for an unspecified oil product, only one series of specifications, but a whole range of features.

In order to determine the values of these characteristics and to make quality controls products before their marketings, each refinery has an analysis laboratory. This one follows, in all the phases of manufacture of the products, the evolution and/or the changes in the characteristics. At the end of the chain, and before the marketable product is put on the market, it is at the analysis laboratory that returns the responsibility to give or not green light in this marketing.

It is the laboratory which in the final analysis delivers the compliance certificate of the product before its marketing. In the event of dispute on behalf of the customers, it is still the laboratory which will play the part of expert in agreement with that of the customer, who, in general, is an independent laboratory.

Concerning the audit process of the characteristics, the laboratories must follow quite precise standards, worked out by approvals national (or international), such as:

  • ASTM ( has merican S ociety for T esting M aterials)

  • NF ( NR elms F rançaises)
  • IP ( I nstitute off P etroleum)

We will give hereafter, for example, some principal characteristics:

  • Densité15/4 (specific gravity60°F/60°F) : it is the report/ratio of the density (the report/ratio masses on volume) product with 15 °C compared to that of measured water with 4°C. Indeed, with 4°C, the density of pure water is equal to 1, i.e. 1 liter of water at this temperature weighs 1 very round kg. Limits MINIMAL and MAXIMUM. It is an important characteristic and it is given for all the saleable products.

  • sulfur Content (sulfur content) (expressed in % mass); as it was known as on several occasions, sulfur and its compounds are very corrosive and corrode metals in the feeding circuits of the fuels. It is thus prohibited everywhere. Also it is a characteristic important to determine. In all logic, for each product one puts a MAXIMUM sulfur limit.

  • Number octane NOR (octane number (RON)) ; this characteristic determines the quality of an automobile fuel. Here the limit is a MINIMAL limit.

  • Distillation (distillation) : it is a characteristic to determine in order to know the behavior of a product under the aspect " carburation" .

For that, one distills the product with the normal pressure and by collecting the volumes distilled at each specific temperature (before 70 °C, before 140 °C and before 195 °C), one determines the quality of the product:
    • the item 10% distilled before 70 °C characterizes the facility of the cold start.
    • the item 50% distilled before 140 °C characterizes the flexibility in the recoveries, because this point indicates a good speed in the evaporation of the gasoline.
    • it point 95% distilled before 195°C wants to say that the fuel does not contain too many harmful heavy products to the engine (risk of coke formation) and gives to the engine a greater longevity.

  • Viscosity (viscosity) : it is the resistance which oppose, molecules of an unspecified liquid, with a force tending to move them. The viscosity of a body decreases when the temperature increases, consequently, viscosity must, always to be given, with a temperature. Without this one, its value does not have any significance. In practice, one determines kinematic viscosity in cSt with 20 °C (fuel domesticates), with 40°C (gas oils) with 50 °C and 100 °C (heavy fuels). There exist two viscosities:

    • the dynamic viscosity absolute, expressed in Poise ,
    • the kinematic Viscosité which is expressed in stores , but generally into Centistoke (cSt). The limit can be MINIMAL or MAXIMUM or both. The values can be given in various practical units:

      • centistoke (cSt)

      • degrees Engler (°E)
      • second Redwood
      • Saybolt Furol
      • Saybolt Universal
      • mm ² /s

  • Index of cetane (cetane index) : this index is comparable with the octane number for the gasolines, but here one measures the ease of ignition fast of the product (gas oils). It is measured with an engine similar to engine CFR. Measurement is done by comparison with a mixture of reference of cetane (this one ignites very well) and of alphamethylnaphtalene which does not ignite spontaneously. For this characteristic, the limit is MINIMAL.

  • Not flash (flash not) : it is the temperature to which the vapors released by the product explode during the application of a flame. The limit is MINIMAL.

  • Point freezing (freezing not) : it is an important characteristic for the Jet Fuel, it is the temperature in °C measured at the time when the first crystals appear. The limit is MAXIMUM.

  • Not of flow (for point) : it is determined by the lowest temperature to which, in the " standardized conditions " a liquid preserves a sufficient fluidity. The limit is MINIMAL.

  • Not of disorder (cloud not) : it is the temperature to which, the product gives a turbid aspect, when one cools it under standardized conditions. The limit is MAXIMUM.

  • limiting Température of filterability (TLF) is the temperature to which, by reduction in the temperature of the product, this one does not manage any more to cross a filter whose characteristics are defined by standards set in advance, while being aspired by a controlled depression. The limit is MAXIMUM.

These characteristics are important, but there is the different one such as corrosion on a copper foil for the fuels, the content of mercaptans (or RSH) for the Jet Fuel, PONA (% in volume of Paraffins, Oléfines, Naphtènes and Aromatic) for heavy naphtha, penetrability, the point of flow, the temperature of softening (ball-ring) for the bitumens, the content of sediments, ashes, heavy metals…

Only the analysis laboratory of the refinery is responsible for the analyzes and its results.

  • external Bond : ASTM (in English)

  • external Bond : ASTM (in English)
  • external Bond : External AFNOR
  • Bond : IP (in English)

The park of storage (Storage)

Generally, where there is oil, there is always a park of storage. Indeed, one finds storage with the places of production, the oil terminals, departure and arrival of the gas pipelines and pipelines and thus in the refineries.

There exists always a park of storage in each refinery. According to the complexity of the refinery, the number of storage vats varies. For each load, for each intermediate and finished product, there is a whole series of vats of various sizes. In for certain products to be reprocessed more there are vats of Slop or vats of Contaminats .

The vats are of two kinds: the vats with floating roof and those with roof fix . At the first, the roof floats and follows the level of the product, while at the last, the roof is fixed.

As propane and butane are gases liquid under pressure, one puts them in Cigare S for propane and of the Sphère S for butane.

As for the crudes, there exist vats for crudes BTS and of the vats for crudes HTS. Indeed, the crudes with low sulfur content are more expensive with the purchase and the products resulting from those are more expensive also with the sale. The number of crude vats depends on capacity for treatment on the refinery. In general, by decantation, the crudes always leave a viscous deposit ( called " slop" ) at the bottom of the vats which should be purged from time to time.

In order to save the construction of the vats, one can also use certain vats to put two different intermediate products, but nevertheless rather close from the characteristics point of view of.

For the end products, according to the market needs, the number of vats is high for certain products and weak for some others.

Apart from the refinery, if the configuration of the ground is favorable, existence of the impermeable underground layers, one digs cavities in the basement to store oil products there. Thus the company Géostock has many of these cavities which it rents with the independent refiners and other users. But the refiners themselves have participations in the capital of Géostock.

To have underground cavities, one seeks saliferous formations, one digs with the wanted depth, then one carries out scrubbing. For that, a casing is installed with two concentric tubes, the external tube must be at the top of the salt plug and the interior tube must be at the base. One injects fresh water and one evacuates the brine, one continues this operation until dimensions of the cavity reach desired volume.

Then, one replaces this casing by a casing of exploitation and one injects the product to be stored under pressure. Other cavities which the saliferous cavities can be used, since the basement lends itself to it: excavated galleries, unused mines.

Thus one finds, in France, of storages of ethylene to Viriat close to Lyon, with Manosque for the storage of crudes, with Small-Crown for the C3/C4, with Lavera for the LPG (liquefied petroleum gas) (LPG, Liquefied Petroleum Gas), and May-on-Flowering ash close to Caen.

Underground storage has several advantages:

  • Discretion,

  • Fire protection,
  • Environmental protection,
  • Esthetic,
  • Saving in investments,
  • Profitability vis-a-vis the distortion of the seasonal requests,
  • convenient Stocks of reserves.

Means of reception and forwarding (Reception & forwarding means)

In order to be able to take delivery of the crudes to be treated and certain products to be reprocessed, and to dispatch the products manufactured towards the places of consumption, it is always envisaged means of reception and forwarding in a refinery.

These means are many and variable depending on the localization of the refinery. If this one is in seaside, it is especially by sea route that the crudes arrive and that the products are dispatched. If it is close to a navigable river by barges and small tankers, it is this means which is used. On the other hand if the refinery is inside the grounds, one can consider various fashions of reception and forwarding: by rail, by tankers, pipeline.

Thus the refinery of Grandpuits is fed out of crudes by the pipeline the Harbor-Grandpuits, and the forwarding of the products is done by barges, by rail and by tankers. It is the same for the refinery of Feyzin which is fed by the pipeline South-European SPSE. On the other hand in Lavéra, the refinery is fed starting from the storage of the oil terminal through a small pipeline. It is the same for the refinery of Yanbu and that of Aramco with Dahran in Saudi Arabia.

In Paris region, the small crude production with Chailly-in-Beer is conveyed in Grandpuits by tankers. For the reception as well as for forwarding, all the means of transport are provided with meters and after counting, received or dispatched volumes are brought back to the normal density ( D15/4 ) to be entered.

See too

Internal bonds

External bonds

  • French Petroleum Institute
  • French Union of oil industries, association of French oil industry
  • the quotation of oil to New York Stock Exchange
  • an explanatory site set up by Total a very useful site for all to know about fossil energies and more particularly about oil…
  • the gate of oil

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