EP3344732B1 - Method for the vacuum distillation of a hydrocarbon feed stock - Google Patents

Method for the vacuum distillation of a hydrocarbon feed stock Download PDF

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Publication number
EP3344732B1
EP3344732B1 EP16759779.8A EP16759779A EP3344732B1 EP 3344732 B1 EP3344732 B1 EP 3344732B1 EP 16759779 A EP16759779 A EP 16759779A EP 3344732 B1 EP3344732 B1 EP 3344732B1
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stream
vacuum distillation
flow
distillation column
heat exchanger
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German (de)
French (fr)
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EP3344732A1 (en
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Patrick COTTIN
Helene PITARD
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Technip Energies France SAS
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Technip France SAS
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    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G7/00—Distillation of hydrocarbon oils
    • C10G7/06—Vacuum distillation

Definitions

  • the present invention relates to a vacuum distillation process for a hydrocarbon feed.
  • US4261814 describes a process of the aforementioned type in which steam is used as the exhaust fluid.
  • WO2013 / 107738 describes another process which requires steam to obtain a satisfactory yield.
  • Such a process is intended in particular for the distillation of a charge of hydrocarbons comprising heavy compounds, having high boiling points.
  • the method is intended for the distillation of a feedstock resulting from the atmospheric distillation of crude oil.
  • the refining of crude oil generally involves atmospheric distillation in which temperatures are kept below 370 ° C - 380 ° C to prevent the high molecular weight components from undergoing thermal cracking and forming petroleum coke.
  • coke is particularly undesirable and is manifested in particular by fouling of the tubes in the furnace used to heat the charge of the distillation column.
  • vacuum distillation is carried out at very low pressures, generally between 13 mbar and 133 mbar (10 mmHg to 100 mmHg), to limit the temperature at the outlet of the oven and consequently limit the risk of cracking. and coke formation by lowering the temperatures required at the outlet.
  • a dewatering flux based on water vapor is introduced into the distillation column under the load, at the bottom of the distillation column. This exhaustion flow is recovered at the top of the column in the form of water vapor, mixed with residual hydrocarbons, then condensed before being treated in a downstream unit.
  • the highest withdrawal in the column from which the light vacuum distillation oils are taken has a non-negligible viscosity at room temperature, which is detrimental for the dimensioning of the air exchangers.
  • An object of the invention is to obtain a vacuum distillation process which has reduced consumption of utilities and a reduction in the size of certain equipment, while retaining at least as good separation performance.
  • the invention relates to a method according to claim 1.
  • a first installation 10 according to the invention is illustrated by the figure 1 .
  • This installation 10 is intended for the implementation of a first method according to the invention, for the vacuum distillation of a charge 12.
  • the installation 10 includes an oven 14 for heating the charge 12 and a depletion fluid, a vacuum distillation column 16, and bottom heat exchangers 18.
  • the installation 10 further comprises lateral withdrawals 20, 22, 24, and, respectively associated with each lateral withdrawal 20, 22, 24, of the respective heat exchangers 26, 28 and 30.
  • the installation 10 comprises '' other types of vacuum distillation arrangements (number of racking 20, 22, 24 variables, number of packing beds 43 variables, number of packing beds 41 variables).
  • the installation 10 includes a downstream heat exchanger 32, a vacuum generation unit 34, and a capacity 36 for condensate recovery.
  • the installation 10 comprises in this example an optional downstream separator 38 for recovering the exhausting fluid and a pump 40 for recycling the exhausting fluid.
  • the vacuum distillation column 16 has a first packing bed 43 whose role is to provide heat exchange over each racking 20, 22, 24, and whose liquid supply is provided by a first diffuser 44.
  • the vacuum distillation column 16 has, below each racking 20, 22, 24, a second packing bed 41, the role of which is to ensure fractionation and the supply of which is ensured by a second liquid diffuser 42.
  • the heat exchangers 26 and 28 are heat exchangers making it possible to cool part of the withdrawals 58 and 64.
  • the downstream heat exchanger 32 is a water exchanger, supplied with a flow of water at ambient temperature.
  • the heat exchangers 30 are air heat exchangers.
  • the vacuum generation unit 34 comprises a plurality of steam jet ejectors 45, mounted in series with each other, and for each ejector 45, a downstream water condenser 46. Depending on the desired vacuum level, the number of ejector stages in series may vary.
  • the unit 34 comprises three ejectors 45 in series and three condensers 46 interposed between the ejectors 45.
  • This charge 12 is for example a charge of liquid hydrocarbons, such as a residual oil charge from an atmospheric distillation.
  • the mass flow rate of the load 12 is generally between 100 t / h and 1000 t / h
  • the charge 12 comes either directly from the bottom of an atmospheric crude distillation column (generally of the order of 350 ° C) or from a storage tank (at a temperature for example of the order of 80 ° C) after reheating to a temperature of the order of 300 ° C.
  • the load 12 is first introduced into the oven 14 to be heated and advantageously vaporized there.
  • the temperature of the heated charge 50 at the outlet of the oven 14 is generally between 380 ° C and 420 ° C depending on the desired distillation performance and the TBP cutting point between the vacuum residue 79 and the vacuum distillate 20 (
  • TBP comes from “True Boiling Point”, an English term meaning “true boiling point.”
  • the cutting points cited represent the distilled fraction of crude oil at the temperatures indicated).
  • the partially vaporized charge 50 is then introduced into the vacuum distillation column 16 at a level N1 located in the flash zone above the bottom of the vacuum distillation column 16.
  • a flow of exhaustion fluid 52 consisting of hydrocarbons having a weighted average boiling point (mean in English or Tmav) between 150 ° C and 250 ° C ( typically of the order of 200 ° C), is introduced into the oven 14 to be heated and advantageously vaporized there.
  • This temperature Tmav is defined in the "Databook on hydrocarbons” written by JB Maxwell under the English expression "mean average boiling point”. The calculation of the temperature Tmav according to the method of JB Maxwell is also detailed in Pierre Wuithier's book “Petroleum - Refining and Chemical Engineering”, Volume 1 .
  • a kerosene from an atmospheric crude distillation having an initial TBP cutting point of between 145 ° C and 180 ° C and a final TBP cutting point of between 220 ° C and 250 ° C advantageously constitutes the exhausting fluid.
  • the exhaustion fluid 52 is completely vaporized and superheated before it is introduced into the bottom of the column 16. A portion of this exhaustion fluid is injected in liquid form into the radiation beam of the vacuum furnace as acceleration fluid in order to limit film temperatures in the tubes.
  • the flow of superheated exhaustion fluid 54 is introduced into the vacuum distillation column 16, at a level N2 situated below the last plate of a depletion zone 56 of the vacuum distillation column 16.
  • the flow of heated exhaustion fluid 54 rises through the plates of the exhaustion zone56 located between the levels N1 and N2 and evaporates the lighter fractions of the residue under vacuum.
  • the vacuum level at the top of the column is advantageously between 13 mbar and 40 mbar (10 mmHg and 30 mmHg), here substantially around 27 mbar (20 mmHg).
  • a first stream 58 of heavy vacuum distillate (“HVGO” or “Heavy Vacuum Gas Oil” in English) is taken laterally at a first racking 20 at a lower level N3 located above the level N1.
  • a first fraction 60 of the heavy vacuum distillate stream 58 is reintroduced into the column 16 through the second diffuser 42 associated with the withdrawal 20.
  • the rest of the heavy vacuum distillate stream 58 passes through a heat exchanger 26 and a second fraction 62 heavy distillate stream 58 from the heat exchanger 26 is reintroduced into the vacuum distillation column 16, through the first diffuser 44 associated with the withdrawal 20.
  • the rest of the stream constitutes the production 180 of heavy vacuum distillate from unity.
  • a second stream 64 of optional middle vacuum distillate (“MVGO” or “Medium Vacuum Gas Oil” in English) is sampled at the level of a second racking 22 at an average level N4 situated above the level N3.
  • MVGO middle vacuum distillate
  • a first fraction 66 of the optional vacuum distillate stream 64 is reintroduced into the vacuum distillation column 16 through the second diffuser 42 associated with the second draw-off 22.
  • the rest of the vacuum middle distillate stream 64 passes through a heat exchanger 28.
  • An optional second fraction 68 of the middle distillate current under vacuum 64 from the heat exchanger 28 is reintroduced into the vacuum distillation column 16, through the first diffuser 44 of the second racking 22.
  • the rest of the current constitutes the production 170 of medium vacuum distillate from the unit.
  • a third stream 70 of light vacuum distillate (“LVGO” or “Light Vacuum Gas Oil” in English) is sampled at the level of a third racking 24 at a high level N5 situated above the level N4, in the vicinity of the head of the vacuum distillation column 16.
  • a first fraction 72 of the light vacuum distillate stream 70 is reintroduced into the vacuum distillation column 16 through the second diffuser 42 associated with the third withdrawal 24.
  • the rest of the stream 70 passes through an air exchanger 30.
  • a second fraction 74 of the light vacuum distillate stream 70 from the heat exchanger 30 is reintroduced into the distillation column 16, through the first diffuser 44 of the third racking 24.
  • the rest of the stream constitutes the production 160 of light distillate vacuum from the unit.
  • a bottom stream 79 is recovered at the bottom of the vacuum distillation column 16 and passes through bottom heat exchangers.
  • a head stream 80 is drawn at the head of the column, under the effect of the suction produced by the vacuum generation unit 34.
  • the head stream 80 has a pressure equal to the column head operating pressure 16 and has a temperature generally between 60 ° C and 100 ° C.
  • the overhead stream 80 is then introduced into the downstream heat exchanger 32, to be partially condensed therein by heat exchange with the water flowing in the downstream heat exchanger 32.
  • the overhead stream 80 is thus separated into a gaseous flow of head 82 and a liquid flow from foot 84.
  • the overhead gas stream 82 is brought to the vacuum generation unit 34. It is introduced into a first ejector 45 where it is entrained by a flow of driving vapor 150. The mixture thus formed is introduced into the first condenser 46, to form a first condensate 86 and a first gas flow 88.
  • the first gas stream 88 is successively introduced into a second ejector 45, then into a second condenser 46, to form a second condensate 90 and a second gas stream 92.
  • the second gas stream 92 is then introduced into a third ejector 45, then into a third condenser 46, to form a third gas stream 94 of noncondensable combustible gas and a third condensate 96 available at a pressure slightly higher than atmospheric pressure.
  • the condensates 86, 90, 96 are recovered in a tank 36 and are separated into a stream of condensed hydrocarbons 98 and a stream of water to be treated 100.
  • the bottom liquid stream 84 contains the majority of the exhaust fluid introduced into the exhaust fluid flow 52 at the bottom of the vacuum distillation column 16. In fact, the boiling temperature of the exhaust fluid 52 is lower than that of the light vacuum distillate stream 70 and is higher than that of water vapor.
  • the exhausting fluid is however more easily condensable than water vapor. This allows the column to be operated at low pressure, as described above.
  • the bottom liquid flow 84 is introduced into the optional downstream separator 38 in equilibrium with the gas flow 82.
  • the fraction of foot 112 contains the majority of the exhaustion fluid. It is pumped into the pump 40 to form a stream 114 for recycling the exhaustion fluid.
  • a purge stream 116 is taken from the recycling stream 114 in order to reduce the amount of impurities and to keep a quality of recycle stream 114 constant and the quality of which will be as close as possible to the additional exhaustion stream 118.
  • purge current 116 generally represents between 5% by mass and 20% by mass of the bottom fraction 112 introduced into the pump 40.
  • the method is implemented without recycling with total purge (the absence of recycle flow being compensated for by an additional supplementary flow 118).
  • the rest of the recycling stream 114 is returned to the furnace 14 to form, with a supply stream 118 of exhaustion fluid, the flow 52 of exhaustion fluid.
  • the removal of the purge current 116 and the supply provided by the supply current 118 make it possible to renew the exhaustion fluid circulating in the process according to the invention. This guarantees the maintenance of a good quality of distillation, and a good aptitude for the condensation of the exhaustion fluid, by eliminating the lighter fractions possibly accumulated.
  • the flow rate of the exhaustion fluid flow 52 introduced into the distillation column 16 can be controlled, by adjusting the respective flow rates of the purge stream 116 and the feed stream 118.
  • Table 1 illustrates the results obtained by numerical simulation for the first process according to the invention, within the framework of the treatment of a hydrocarbon charge 12 with a mass flow rate equal to 666.7 t / h resulting from the distillation atmospheric of a “OURAL” type of crude.
  • the exhaustion fluid is kerosene from from an atmospheric distillation having a TBP cutting point 145 ° C-230 ° C, a molecular weight of 152 g / mol and a density at 15 ° C of 0.781.
  • the temperatures are higher at the top of the column 16, which allows a temperature of the flow 74 higher than in a conventional scheme.
  • the viscosity of the flow 74 is then reduced, reducing the size of the first air heat exchanger 30.
  • the size of the downstream heat exchanger 32 is reduced because there is no longer any water vapor to condense.
  • a portion 119 of the flow of drive fluid 52 is derived in the load 12 before its passage through the oven 14 or during this passage.
  • a second installation 130 according to the invention is illustrated on the figure 2 .
  • the second installation 130 is intended for the implementation of a second vacuum distillation process according to the invention.
  • downstream heat exchanger 32 of the second installation 130 is disposed directly in the distillation column 16, at the head of the column, above the upper bed 43 associated with the upper withdrawal. 30.
  • the downstream heat exchanger 32 is here a plate heat exchanger with low pressure drop (typically less than 7 mbar (5 mmHg), in particular of the order of 1.3 mbar (1 mmHg)).
  • the overhead vapors forming the overhead stream 80 from the distillation in the vacuum distillation column 16 penetrate into the heat exchanger 32 within the vacuum distillation column 16 from above.
  • the overhead current 80 condenses in the heat exchanger 32.
  • a gas flow 82 is extracted from the heat exchanger 32, to be brought to the vacuum generation unit 34 and a bottom liquid flow 84 is recovered at the bottom of the heat exchanger 32, to be brought into the downstream separator 38.
  • the table below illustrates the results obtained for the second process according to the invention, within the framework of the treatment of a hydrocarbon charge 12 with a mass flow rate equal to 666.7 t / h, resulting from the atmospheric distillation of a “OURAL” type of rough.
  • the exhaustion fluid is kerosene from an atmospheric distillation having a TBP cutting point 145 ° C - 230 ° C, a molecular weight of 152 g / mol and a density at 15 ° C of 0.781.
  • the process illustrated in figure 2 has an even lower pressure at the top of the column, for example less than 27 mbar (20 mmHg), and in particular between 13 mbar (10 mmHg) and 20 mbar (15 mmHg).
  • this diagram reduces the flow of exhausting fluid 52 necessary, while retaining a reduced heat exchange surface in the downstream heat exchanger 32, and in the exchangers 30.
  • the consumption of cooling water is also further reduced, given the lower quantity of exhaustion fluid to be condensed in the heat exchanger 32.
  • the exchanger 32 is located outside of the distillation column 16.
  • the performances of this variant lie between the performances obtained with the installation shown on the figure 1 and the performance obtained with the installation shown on the figure 2 .
  • a third installation 140 according to the invention is illustrated by the figure 3 .
  • the installation 140 comprises a second downstream heat exchanger 142 disposed downstream of the first downstream heat exchanger 32 located in the vacuum distillation column 16.
  • the second downstream heat exchanger 142 is disposed outside of the vacuum distillation column 16, and receives the gas flow 82 from the first downstream heat exchanger 32.
  • the second downstream heat exchanger 142 is a plate heat exchanger with low pressure drop (typically less than 7 mbar (5 mmHg), in particular of the order of 1.3 mbar (1 mmHg)). It is here provided with a boom 143 for spraying a stream of liquid hydrocarbons 144, typically a stream coming from the atmospheric distillation installation.
  • the stream of liquid hydrocarbons 144 is for example an atmospheric heavy distillate stream (“HAGO” or “Heavy Atmospheric Gas Oil” in English).
  • the third vacuum distillation process according to the invention differs from the second process in that the overhead flow 82 produced in the first downstream heat exchanger 32 is introduced into the second heat exchanger 142.
  • the head flow 82 is at least partially condensed on the one hand, thanks to the absorption generated by the introduction of the fluid 144, and on the other hand, by heat exchange with the water.
  • An additional condensate 146 is produced at the foot of the second downstream heat exchanger 142, the rest of the gas flow 82 being introduced into the vacuum generation unit 34, as described above.
  • the additional condensate is collected in capacity 36.
  • the table below illustrates the results obtained for the third process according to the invention, in the context of the treatment of a hydrocarbon charge 12 with a mass flow rate equal to 666.7 t / h resulting from the atmospheric distillation of a "OURAL" type raw.
  • the exhaustion fluid is kerosene.
  • the third method according to the invention further reduces the steam consumption of the vacuum generation unit 34.
  • the overall consumption of fuel in the process is further reduced, as well as the quantity of water to be treated 100 produced.
  • the methods according to the invention considerably reduce the consumption of utilities, in particular of cooling water and in water vapor, which reduces the operating costs of the installation, while retaining a process which makes it possible to achieve ambitious performances of recovery rate of distillates under vacuum.
  • the flow rate of supply current 118 in exhaustion fluid can be controlled independently of the nature and flow rate of the charge 12, and independently of the flow rate of recycling current 114. The latter making it possible to supply the quantity and the quality of exhaustion fluid 52 necessary for the quality of distillation.
  • the ratio between the mass flow rate of the exhausting fluid 52 introduced into the vacuum distillation column 16 and the mass flow rate of the net bottom stream 190 recovered from the bottom of the vacuum distillation column 16 (after derivation of a quenching current returned to the vacuum distillation column 16) is greater than 80 kg of exhaustion fluid per 1000 kg of net bottom current recovered at the bottom of the vacuum distillation column 16 and is in particular between 80 kg and 800 kg of exhaustion fluid for 1000 kg of net bottom current recovered from the bottom of the vacuum distillation column 16.
  • the quality of the depletion fluid 52 used consisting of a mixture of hydrocarbons having a weighted average boiling temperature (Tmav) of between 150 ° C and 250 ° C advantageously between 190 ° C and 210 ° C , is perfectly mastered in the process according to the invention.
  • Tmav weighted average boiling temperature
  • Such a fluid is optimal since it ensures efficient exhaustion of the charge 12, while being easily condensable at very low pressure at the top of the vacuum distillation column 16, and therefore recyclable through the liquid stream 114.
  • the fluid 52 has the advantage of being almost completely recovered in the column head stream 80. This allows recycling and avoids the extraction of exhaustion fluid 52 in the distillate streams 160, 170, 180 in particular in stream 160 of light vacuum distillate.
  • more than 95% by mass of the exhausting fluid 52 introduced into the vacuum distillation column 16 is recovered from the vacuum distillation column 16 in the stream 112 via the column head stream 80 after condensation.

Description

La présente invention concerne un procédé de distillation sous vide d'une charge d'hydrocarbures.The present invention relates to a vacuum distillation process for a hydrocarbon feed.

US4261814 décrit un procédé du type précité dans lequel de la vapeur est utilisée comme fluide d'épuisement. WO2013/107738 décrit un autre procédé qui nécessite de la vapeur pour obtenir un rendement satisfaisant.. US4261814 describes a process of the aforementioned type in which steam is used as the exhaust fluid. WO2013 / 107738 describes another process which requires steam to obtain a satisfactory yield.

Un tel procédé est destiné notamment à la distillation d'une charge d'hydrocarbures comprenant des composés lourds, présentant des points d'ébullition élevés. En particulier, le procédé est destiné à la distillation d'une charge résultant de la distillation atmosphérique du pétrole brut.Such a process is intended in particular for the distillation of a charge of hydrocarbons comprising heavy compounds, having high boiling points. In particular, the method is intended for the distillation of a feedstock resulting from the atmospheric distillation of crude oil.

Le raffinage du pétrole brut comprend généralement une distillation atmosphérique dans laquelle les températures sont maintenues inférieures à 370°C - 380 °C pour éviter que les composants de masse moléculaire élevée subissent un craquage thermique et forment du coke de pétrole.The refining of crude oil generally involves atmospheric distillation in which temperatures are kept below 370 ° C - 380 ° C to prevent the high molecular weight components from undergoing thermal cracking and forming petroleum coke.

La formation de coke est particulièrement indésirable et se traduit notamment par un encrassement des tubes dans le four servant à chauffer la charge de la colonne de distillation.The formation of coke is particularly undesirable and is manifested in particular by fouling of the tubes in the furnace used to heat the charge of the distillation column.

Du fait de la limitation de la température de chauffe, la distillation atmosphérique produit une huile résiduelle qui est recueillie à la partie inférieure de la colonne de distillation atmosphérique. Cette huile comporte des hydrocarbures qui présentent en général des points d'ébullition au-delà de 350 °C.Due to the limitation of the heating temperature, atmospheric distillation produces a residual oil which is collected at the bottom of the atmospheric distillation column. This oil contains hydrocarbons which generally have boiling points above 350 ° C.

Cette huile est alors distillée sous vide pour récupérer des distillats valorisables. À cet effet, la distillation sous vide est opérée à des pressions très faibles généralement comprises entre 13 mbars et 133 mbars (10 mmHg à 100 mmHg), pour limiter la température de sortie du four et par voie de conséquence, limiter le risque de craquage et de formation de coke en abaissant les températures requises en sortie .This oil is then distilled under vacuum to recover recoverable distillates. To this end, vacuum distillation is carried out at very low pressures, generally between 13 mbar and 133 mbar (10 mmHg to 100 mmHg), to limit the temperature at the outlet of the oven and consequently limit the risk of cracking. and coke formation by lowering the temperatures required at the outlet.

Pour réaliser ce niveau de vide, il est connu d'utiliser une unité de génération de vide comprenant plusieurs étages d'éjecteurs à jet de vapeur installés en série. Ces éjecteurs requièrent une consommation significative de vapeur motrice.To achieve this level of vacuum, it is known to use a vacuum generation unit comprising several stages of steam jet ejectors installed in series. These ejectors require a significant consumption of driving steam.

Par ailleurs, à ce niveau de vide, la condensation des hydrocarbures légers et de la vapeur d'eau récupérés en tête de colonne nécessite une consommation très importante en eau de refroidissement.Furthermore, at this vacuum level, the condensation of light hydrocarbons and water vapor recovered at the head of the column requires a very high consumption of cooling water.

Pour faciliter la distillation, un flux d'épuisement à base de vapeur d'eau est introduit dans la colonne de distillation sous la charge, au pied de la colonne de distillation. Ce flux d'épuisement est récupéré en tête de colonne sous forme de vapeur d'eau, mélangée aux hydrocarbures résiduels, puis condensé avant d'être traité dans une unité aval.To facilitate distillation, a dewatering flux based on water vapor is introduced into the distillation column under the load, at the bottom of the distillation column. This exhaustion flow is recovered at the top of the column in the form of water vapor, mixed with residual hydrocarbons, then condensed before being treated in a downstream unit.

Enfin, le soutirage le plus élevé dans la colonne où sont prélevées les huiles légères de distillation sous vide a une viscosité non négligeable à température ambiante, ce qui est pénalisant pour le dimensionnement des échangeurs à air.Finally, the highest withdrawal in the column from which the light vacuum distillation oils are taken has a non-negligible viscosity at room temperature, which is detrimental for the dimensioning of the air exchangers.

Un but de l'invention est d'obtenir un procédé de distillation sous vide qui présente une consommation en utilités diminuée et une réduction de la taille de certains équipements, tout en conservant des performances au moins aussi bonnes de séparation.An object of the invention is to obtain a vacuum distillation process which has reduced consumption of utilities and a reduction in the size of certain equipment, while retaining at least as good separation performance.

A cet effet, l'invention a pour objet un procédé selon la revendication 1..To this end, the invention relates to a method according to claim 1.

Suivant des modes particuliers de réalisation, le procédé selon l'invention comprend l'une ou plusieurs des caractéristiques des revendications 2 à 13 ou des caractéristiques suivantes, prise(s) isolément ou suivant toute combinaison techniquement possible :

  • il comprend la récupération d'un courant de fond net en bas de la colonne de distillation sous vide, le rapport entre le débit massique du fluide d'épuisement introduit dans la colonne de distillation sous vide et le débit massique du courant de fond net récupéré au fond de la colonne de distillation sous vide est supérieur à 80 kg de fluide d'épuisement pour 1000 kg de courant de fond net récupéré au fond de la colonne de distillation sous vide et est notamment compris entre 80 kg et 800 kg de fluide d'épuisement pour 1000 kg de courant de fond net récupéré au fond de la colonne de distillation sous vide;
  • plus de 95 % en masse du fluide d'épuisement introduit dans la colonne de distillation sous vide est extrait de la colonne de distillation sous vide via le courant de tête de colonne.
According to particular embodiments, the method according to the invention comprises one or more of the features of claims 2 to 13 or of the following features, taken in isolation or according to any technically possible combination:
  • it includes the recovery of a net bottom stream at the bottom of the vacuum distillation column, the ratio between the mass flow rate of the exhaust fluid introduced into the vacuum distillation column and the mass flow rate of the net bottom stream recovered at the bottom of the vacuum distillation column is greater than 80 kg of exhaustion fluid for 1000 kg of net bottom current recovered at the bottom of the vacuum distillation column and is in particular between 80 kg and 800 kg of fluid d 'exhaustion per 1000 kg of net bottom stream recovered from the bottom of the vacuum distillation column;
  • more than 95% by mass of the exhaust fluid introduced into the vacuum distillation column is extracted from the vacuum distillation column via the column overhead stream.

L'invention sera mieux comprise à la lecture de la description qui va suivre, donnée uniquement à titre d'exemple, et faite en se référant aux dessins annexés, sur lesquels :

  • la figure 1 est un schéma synoptique d'une première installation de distillation sous vide, destinée à la mise en œuvre d'un premier procédé selon l'invention ;
  • la figure 2 est une vue analogue à la figure 1, d'une deuxième installation de distillation sous vide, destinée à la mise en œuvre d'un deuxième procédé selon l'invention ;
  • la figure 3 est une vue analogue à la figure 1, d'une troisième installation de distillation sous vide, destinée à la mise en œuvre d'un troisième procédé selon l'invention.
The invention will be better understood on reading the description which follows, given only by way of example, and made with reference to the appended drawings, in which:
  • the figure 1 is a block diagram of a first vacuum distillation installation, intended for the implementation of a first process according to the invention;
  • the figure 2 is a view analogous to the figure 1 , a second vacuum distillation installation, intended for the implementation of a second method according to the invention;
  • the figure 3 is a view analogous to the figure 1 , of a third vacuum distillation installation, intended for the implementation of a third process according to the invention.

Dans tout ce qui suit, on désignera par les mêmes références un courant circulant dans une conduite et la conduite qui le transporte.In all that follows, the current references will denote a current flowing in a pipe and the pipe which transports it.

En outre, sauf indication contraire, les débits cités sont des débits massiques, les pressions sont données en millibars absolus.In addition, unless otherwise indicated, the flow rates quoted are mass flow rates, the pressures are given in absolute millibars.

Une première installation 10 selon l'invention est illustrée par la figure 1. Cette installation 10 est destinée à la mise en œuvre d'un premier procédé selon l'invention, pour la distillation sous vide d'une charge 12.A first installation 10 according to the invention is illustrated by the figure 1 . This installation 10 is intended for the implementation of a first method according to the invention, for the vacuum distillation of a charge 12.

L'installation 10 comporte un four 14 de chauffage de la charge 12 et d'un fluide d'épuisement, une colonne de distillation sous vide 16, et des échangeurs thermiques de fond 18.The installation 10 includes an oven 14 for heating the charge 12 and a depletion fluid, a vacuum distillation column 16, and bottom heat exchangers 18.

L'installation 10 comporte en outre des soutirages latéraux 20, 22, 24, et, associés respectivement à chaque soutirage latéral 20, 22, 24, des échangeurs thermiques respectifs 26, 28 et 30. Dans des variantes, l'installation 10 comporte d'autres types d'arrangements de distillation sous vide (nombre de soutirage 20, 22, 24 variables, nombre de lits de garnissage 43 variables, nombre de lits de garnissage 41 variables).The installation 10 further comprises lateral withdrawals 20, 22, 24, and, respectively associated with each lateral withdrawal 20, 22, 24, of the respective heat exchangers 26, 28 and 30. In variants, the installation 10 comprises '' other types of vacuum distillation arrangements (number of racking 20, 22, 24 variables, number of packing beds 43 variables, number of packing beds 41 variables).

L'installation 10 comporte un échangeur thermique aval 32, une unité 34 de génération de vide, et une capacité 36 de récupération de condensats.The installation 10 includes a downstream heat exchanger 32, a vacuum generation unit 34, and a capacity 36 for condensate recovery.

L'installation 10 comporte dans cet exemple un séparateur aval 38 optionnel de récupération du fluide d'épuisement et une pompe 40 de recyclage du fluide d'épuisement.The installation 10 comprises in this example an optional downstream separator 38 for recovering the exhausting fluid and a pump 40 for recycling the exhausting fluid.

Dans cet exemple, la colonne de distillation sous vide 16 présente, un premier lit de garnissage 43 dont le rôle est d'assurer un échange thermique au-dessus de chaque soutirage 20, 22, 24, et dont l'alimentation liquide est assurée par un premier diffuseur 44. La colonne de distillation sous vide 16 présente, au-dessous de chaque soutirage 20, 22, 24, un deuxième lit 41 de garnissage, dont le rôle est d'assurer un fractionnement et dont l'alimentation est assurée par un deuxième diffuseur de liquide 42.In this example, the vacuum distillation column 16 has a first packing bed 43 whose role is to provide heat exchange over each racking 20, 22, 24, and whose liquid supply is provided by a first diffuser 44. The vacuum distillation column 16 has, below each racking 20, 22, 24, a second packing bed 41, the role of which is to ensure fractionation and the supply of which is ensured by a second liquid diffuser 42.

Dans l'exemple représenté sur la figure 1, les échangeurs thermiques 26 et 28 sont des échangeurs thermiques permettant de refroidir une partie des soutirages 58 et 64. L'échangeur thermique aval 32 est un échangeur à eau, alimenté par un flux d'eau à température ambiante. Les échangeurs thermiques 30 sont des échangeurs thermiques à air.In the example shown in the figure 1 , the heat exchangers 26 and 28 are heat exchangers making it possible to cool part of the withdrawals 58 and 64. The downstream heat exchanger 32 is a water exchanger, supplied with a flow of water at ambient temperature. The heat exchangers 30 are air heat exchangers.

L'unité de génération de vide 34 comporte une pluralité d'éjecteurs à jet de vapeur 45, montés en série les uns des autres, et pour chaque éjecteur 45, un condenseur aval 46 à eau. En fonction du niveau de vide recherché, le nombre d'étages d'éjecteurs en série pourra varier.The vacuum generation unit 34 comprises a plurality of steam jet ejectors 45, mounted in series with each other, and for each ejector 45, a downstream water condenser 46. Depending on the desired vacuum level, the number of ejector stages in series may vary.

Dans l'exemple représenté sur la figure 1, l'unité 34 comporte trois éjecteurs 45 en série et trois condenseurs 46 interposés entre les éjecteurs 45.In the example shown in the figure 1 , the unit 34 comprises three ejectors 45 in series and three condensers 46 interposed between the ejectors 45.

Un premier procédé de distillation sous vide de la charge 12 dans l'installation 10 va maintenant être décrit.A first method of vacuum distillation of the charge 12 in the installation 10 will now be described.

Initialement, la charge 12 est fournie. Cette charge 12 est par exemple une charge d'hydrocarbures liquides, telle qu'une charge d'huile résiduelle provenant d'une distillation atmosphérique.Initially, the load 12 is supplied. This charge 12 is for example a charge of liquid hydrocarbons, such as a residual oil charge from an atmospheric distillation.

Le débit massique de la charge 12 est en général compris entre 100 t/h et 1000 t/h
La charge 12 est issue soit directement du fond d'une colonne de distillation atmosphérique de brut (généralement de l'ordre de 350°C) ou soit d'un bac de stockage (à une température par exemple de l'ordre de 80°C) après réchauffage jusqu'à une température de l'ordre de 300°C. La charge 12 est tout d'abord introduite dans le four 14 pour y être réchauffée et avantageusement vaporisée.The mass flow rate of the load 12 is generally between 100 t / h and 1000 t / h
The charge 12 comes either directly from the bottom of an atmospheric crude distillation column (generally of the order of 350 ° C) or from a storage tank (at a temperature for example of the order of 80 ° C) after reheating to a temperature of the order of 300 ° C. The load 12 is first introduced into the oven 14 to be heated and advantageously vaporized there.

La température de la charge réchauffée 50 à la sortie du four 14 est généralement comprise entre 380 °C et 420 °C en fonction des performances de distillation recherchées et du point de coupe TBP entre le résidu sous vide 79 et le distillat sous vide 20 (L'acronyme TBP provient de « True Boiling Point », terme anglais signifiant « point d'ébullition véritable ». Les points de coupe cités représentent la fraction distillée du brut aux températures indiquées).The temperature of the heated charge 50 at the outlet of the oven 14 is generally between 380 ° C and 420 ° C depending on the desired distillation performance and the TBP cutting point between the vacuum residue 79 and the vacuum distillate 20 ( The acronym TBP comes from “True Boiling Point”, an English term meaning “true boiling point.” The cutting points cited represent the distilled fraction of crude oil at the temperatures indicated).

La charge partiellement vaporisée 50 est ensuite introduite dans la colonne de distillation sous vide 16 à un niveau N1 situé dans la zone de flash au-dessus du fond de la colonne de distillation sous vide 16.The partially vaporized charge 50 is then introduced into the vacuum distillation column 16 at a level N1 located in the flash zone above the bottom of the vacuum distillation column 16.

Simultanément, et selon l'invention, un flux de fluide d'épuisement 52, constitué d'hydrocarbures présentant une température moyenne d'ébullition pondérée (mean average boiling point » en anglais ou Tmav) comprise entre 150°C et 250°C (typiquement de l'ordre de 200°C), est introduit dans le four 14 pour y être réchauffé et avantageusement vaporisé. Cette température Tmav est définie dans le « Databook on hydrocarbons » écrit par J.B. Maxwell sous l'expression anglaise « mean average boiling point ». Le calcul de la température Tmav selon la méthode de J.B. Maxwell est également détaillé dans l'ouvrage de Pierre Wuithier « Le Pétrole - Raffinage et Génie Chimique », Volume 1 .Simultaneously, and according to the invention, a flow of exhaustion fluid 52, consisting of hydrocarbons having a weighted average boiling point (mean in English or Tmav) between 150 ° C and 250 ° C ( typically of the order of 200 ° C), is introduced into the oven 14 to be heated and advantageously vaporized there. This temperature Tmav is defined in the "Databook on hydrocarbons" written by JB Maxwell under the English expression "mean average boiling point". The calculation of the temperature Tmav according to the method of JB Maxwell is also detailed in Pierre Wuithier's book “Petroleum - Refining and Chemical Engineering”, Volume 1 .

Un kérosène issu d'une distillation atmosphérique de brut ayant un point de coupe TBP initial compris entre 145°C et 180°C et un point de coupe TBP final compris entre 220°C et 250°C constitue avantageusement le fluide d'épuisement.A kerosene from an atmospheric crude distillation having an initial TBP cutting point of between 145 ° C and 180 ° C and a final TBP cutting point of between 220 ° C and 250 ° C advantageously constitutes the exhausting fluid.

Le fluide d'épuisement 52 est totalement vaporisé et surchauffé avant son introduction en fond de colonne 16. Une partie de ce fluide d'épuisement est injecté sous forme liquide dans le faisceau de radiation de four sous vide comme fluide d'accélération afin de limiter les températures de film dans les tubes.The exhaustion fluid 52 is completely vaporized and superheated before it is introduced into the bottom of the column 16. A portion of this exhaustion fluid is injected in liquid form into the radiation beam of the vacuum furnace as acceleration fluid in order to limit film temperatures in the tubes.

Le flux de fluide d'épuisement surchauffé 54 est introduit dans la colonne de distillation sous vide 16, à un niveau N2 situé en dessous du dernier plateau d'une zone d'épuisement 56 de la colonne de distillation sous vide 16.The flow of superheated exhaustion fluid 54 is introduced into the vacuum distillation column 16, at a level N2 situated below the last plate of a depletion zone 56 of the vacuum distillation column 16.

Le flux de fluide d'épuisement réchauffé 54 remonte à travers les plateaux de la zone d'épuisement56 situé entre les niveaux N1 et N2 et revaporise les fractions les plus légères du résidu sous vide.The flow of heated exhaustion fluid 54 rises through the plates of the exhaustion zone56 located between the levels N1 and N2 and evaporates the lighter fractions of the residue under vacuum.

Dans la colonne de distillation sous vide 16, le niveau de vide en tête de colonne est avantageusement compris entre 13 mbars et 40 mbars (10 mmHg et 30 mmHg), ici sensiblement autour de 27 mbars (20 mmHg).In the vacuum distillation column 16, the vacuum level at the top of the column is advantageously between 13 mbar and 40 mbar (10 mmHg and 30 mmHg), here substantially around 27 mbar (20 mmHg).

Un premier courant 58 de distillat lourd sous vide (« HVGO » ou « Heavy Vacuum Gas Oil » en anglais) est prélevé latéralement au niveau d'un premier soutirage 20 à un niveau inférieur N3 situé au-dessus du niveau N1.A first stream 58 of heavy vacuum distillate (“HVGO” or “Heavy Vacuum Gas Oil” in English) is taken laterally at a first racking 20 at a lower level N3 located above the level N1.

Une première fraction 60 du courant de distillat lourd sous vide 58 est réintroduite dans la colonne 16 à travers le deuxième diffuseur 42 associé au soutirage 20. Le reste du courant de distillat lourd sous vide 58 passe dans un échangeur thermique 26 et une deuxième fraction 62 du courant de distillat lourd 58 issue de l'échangeur thermique 26 est réintroduite dans la colonne de distillation sous vide 16, à travers le premier diffuseur 44 associé au soutirage 20. Le reste du courant constitue la production 180 de distillat lourd sous vide issue de l'unité.A first fraction 60 of the heavy vacuum distillate stream 58 is reintroduced into the column 16 through the second diffuser 42 associated with the withdrawal 20. The rest of the heavy vacuum distillate stream 58 passes through a heat exchanger 26 and a second fraction 62 heavy distillate stream 58 from the heat exchanger 26 is reintroduced into the vacuum distillation column 16, through the first diffuser 44 associated with the withdrawal 20. The rest of the stream constitutes the production 180 of heavy vacuum distillate from unity.

Un deuxième courant 64 de distillat moyen sous vide optionnel (« MVGO » ou « Médium Vacuum Gas Oil » en anglais) est prélevé au niveau d'un deuxième soutirage 22 à un niveau moyen N4 situé au-dessus du niveau N3.A second stream 64 of optional middle vacuum distillate (“MVGO” or “Medium Vacuum Gas Oil” in English) is sampled at the level of a second racking 22 at an average level N4 situated above the level N3.

Une première fraction 66 du courant optionnel de distillat moyen sous vide 64 est réintroduite dans la colonne de distillation sous vide 16 à travers le deuxième diffuseur 42 associé au deuxième soutirage 22. Le reste du courant de distillat moyen sous vide 64 passe dans un échangeur thermique 28. Une deuxième fraction 68 optionnel du courant de distillat moyen sous vide 64 issue de l'échangeur thermique 28 est réintroduite dans la colonne de distillation sous vide 16, à travers le premier diffuseur 44 du deuxième soutirage 22. Le reste du courant constitue la production 170 de distillat moyen sous vide issue de l'unité.A first fraction 66 of the optional vacuum distillate stream 64 is reintroduced into the vacuum distillation column 16 through the second diffuser 42 associated with the second draw-off 22. The rest of the vacuum middle distillate stream 64 passes through a heat exchanger 28. An optional second fraction 68 of the middle distillate current under vacuum 64 from the heat exchanger 28 is reintroduced into the vacuum distillation column 16, through the first diffuser 44 of the second racking 22. The rest of the current constitutes the production 170 of medium vacuum distillate from the unit.

Un troisième courant 70 de distillat léger sous vide (« LVGO » ou « Light Vacuum Gas Oil » en anglais) est prélevé au niveau d'un troisième soutirage 24 à un niveau haut N5 situé au-dessus du niveau N4, au voisinage de la tête de la colonne de distillation sous vide 16.A third stream 70 of light vacuum distillate (“LVGO” or “Light Vacuum Gas Oil” in English) is sampled at the level of a third racking 24 at a high level N5 situated above the level N4, in the vicinity of the head of the vacuum distillation column 16.

Une première fraction 72 du courant de distillat léger sous vide 70 est réintroduite dans la colonne de distillation sous vide 16 à travers le deuxième diffuseur 42 associé au troisième soutirage 24. Le reste du courant 70 passe dans un échangeur 30 à air. Une deuxième fraction 74 du courant de distillat léger sous vide 70 issue de l'échangeur thermique 30 est réintroduite dans la colonne de distillation 16, à travers le premier diffuseur 44 du troisième soutirage 24. Le reste du courant constitue la production 160 de distillat léger sous vide issue de l'unité.A first fraction 72 of the light vacuum distillate stream 70 is reintroduced into the vacuum distillation column 16 through the second diffuser 42 associated with the third withdrawal 24. The rest of the stream 70 passes through an air exchanger 30. A second fraction 74 of the light vacuum distillate stream 70 from the heat exchanger 30 is reintroduced into the distillation column 16, through the first diffuser 44 of the third racking 24. The rest of the stream constitutes the production 160 of light distillate vacuum from the unit.

Un courant de fond 79 est récupéré en bas de la colonne de distillation sous vide 16 et passe à travers des échangeurs thermiques de fond.A bottom stream 79 is recovered at the bottom of the vacuum distillation column 16 and passes through bottom heat exchangers.

Un courant de tête 80 est tiré en tête de la colonne, sous l'effet de l'aspiration produite par l'unité de génération de vide 34.A head stream 80 is drawn at the head of the column, under the effect of the suction produced by the vacuum generation unit 34.

Le courant de tête 80 a une pression égale à la pression d'opération de tête de colonne 16 et a une température comprise généralement entre 60 °C et 100°C.The head stream 80 has a pressure equal to the column head operating pressure 16 and has a temperature generally between 60 ° C and 100 ° C.

Le courant de tête 80 est ensuite introduit dans l'échangeur thermique aval 32, pour y être partiellement condensé par échange thermique avec l'eau circulant dans l'échangeur thermique aval 32. Le courant de tête 80 est ainsi séparé en un flux gazeux de tête 82 et un flux liquide de pied 84.The overhead stream 80 is then introduced into the downstream heat exchanger 32, to be partially condensed therein by heat exchange with the water flowing in the downstream heat exchanger 32. The overhead stream 80 is thus separated into a gaseous flow of head 82 and a liquid flow from foot 84.

Le flux gazeux de tête 82 est amené jusqu'à l'unité de génération de vide 34. Il est introduit dans un premier éjecteur 45 où il est entraîné par un flux de vapeur motrice 150. Le mélange ainsi formé est introduit dans le premier condenseur 46, pour former un premier condensat 86 et un premier flux gazeux 88.The overhead gas stream 82 is brought to the vacuum generation unit 34. It is introduced into a first ejector 45 where it is entrained by a flow of driving vapor 150. The mixture thus formed is introduced into the first condenser 46, to form a first condensate 86 and a first gas flow 88.

Le premier flux gazeux 88 est introduit successivement dans un deuxième éjecteur 45, puis dans un deuxième condenseur 46, pour former un deuxième condensat 90 et un deuxième flux gazeux 92.The first gas stream 88 is successively introduced into a second ejector 45, then into a second condenser 46, to form a second condensate 90 and a second gas stream 92.

Le deuxième flux gazeux 92 est alors introduit dans un troisième éjecteur 45, puis dans un troisième condenseur 46, pour former un troisième flux gazeux 94 de gaz combustible incondensable et un troisième condensat 96 disponible à une pression légèrement supérieure à la pression atmosphérique.The second gas stream 92 is then introduced into a third ejector 45, then into a third condenser 46, to form a third gas stream 94 of noncondensable combustible gas and a third condensate 96 available at a pressure slightly higher than atmospheric pressure.

Les condensats 86, 90, 96 sont récupérés dans une capacité 36 et sont séparés en un courant d'hydrocarbures condensés 98 et en un courant d'eau à traiter 100.The condensates 86, 90, 96 are recovered in a tank 36 and are separated into a stream of condensed hydrocarbons 98 and a stream of water to be treated 100.

Le flux liquide de pied 84 contient la majorité du fluide d'épuisement introduit dans le flux de fluide d'épuisement 52 au pied de la colonne de distillation sous vide 16. En effet, la température d'ébullition du fluide d'épuisement 52 est inférieure à celle du courant de distillat léger sous vide 70 et est supérieure à celle de la vapeur d'eau.The bottom liquid stream 84 contains the majority of the exhaust fluid introduced into the exhaust fluid flow 52 at the bottom of the vacuum distillation column 16. In fact, the boiling temperature of the exhaust fluid 52 is lower than that of the light vacuum distillate stream 70 and is higher than that of water vapor.

Le fluide d'épuisement est cependant plus facilement condensable que la vapeur d'eau. Ceci permet d'opérer la colonne à une pression faible, tel que décrit plus haut.The exhausting fluid is however more easily condensable than water vapor. This allows the column to be operated at low pressure, as described above.

Le flux liquide de pied 84 est introduit dans le séparateur aval 38 optionnel en équilibre avec le flux gazeux 82.The bottom liquid flow 84 is introduced into the optional downstream separator 38 in equilibrium with the gas flow 82.

La fraction de pied 112 contient la majorité du fluide d'épuisement. Elle est pompée dans la pompe 40 pour former un courant 114 de recyclage du fluide d'épuisement.The fraction of foot 112 contains the majority of the exhaustion fluid. It is pumped into the pump 40 to form a stream 114 for recycling the exhaustion fluid.

Un courant de purge 116 est prélevé dans le courant de recyclage 114 pour diminuer la quantité d'impuretés et conserver une qualité de courant de recycle 114 constante et dont la qualité sera la plus proche possible du flux d'épuisement d'appoint 118. Le courant de purge 116 représente généralement entre 5% massique et 20% massique de la fraction de pied 112 introduite dans la pompe 40. En variante, le procédé est mis en œuvre sans recyclage à purge totale (l'absence de débit de recycle étant compensé par un débit supplémentaire d'appoint 118).A purge stream 116 is taken from the recycling stream 114 in order to reduce the amount of impurities and to keep a quality of recycle stream 114 constant and the quality of which will be as close as possible to the additional exhaustion stream 118. purge current 116 generally represents between 5% by mass and 20% by mass of the bottom fraction 112 introduced into the pump 40. As a variant, the method is implemented without recycling with total purge (the absence of recycle flow being compensated for by an additional supplementary flow 118).

En référence à la figure 1, le reste du courant de recyclage 114 est ramené vers le four 14 pour former, avec un courant d'apport 118 en fluide d'épuisement, le flux 52 de fluide d'épuisement.With reference to the figure 1 , the rest of the recycling stream 114 is returned to the furnace 14 to form, with a supply stream 118 of exhaustion fluid, the flow 52 of exhaustion fluid.

Le prélèvement du courant de purge 116 et l'apport fourni par le courant d'apport 118 permettent de renouveler le fluide d'épuisement circulant dans le procédé selon l'invention. Ceci garantit le maintien d'une bonne qualité de distillation, et une bonne aptitude à la condensation du fluide d'épuisement, en éliminant les fractions les plus légères éventuellement accumulées.The removal of the purge current 116 and the supply provided by the supply current 118 make it possible to renew the exhaustion fluid circulating in the process according to the invention. This guarantees the maintenance of a good quality of distillation, and a good aptitude for the condensation of the exhaustion fluid, by eliminating the lighter fractions possibly accumulated.

Par ailleurs, le débit du flux de fluide d'épuisement 52 introduit dans la colonne de distillation 16 peut être contrôlé, en ajustant les débits respectifs du courant de purge 116 et du courant d'apport 118.Furthermore, the flow rate of the exhaustion fluid flow 52 introduced into the distillation column 16 can be controlled, by adjusting the respective flow rates of the purge stream 116 and the feed stream 118.

Le Tableau 1 ci-dessous illustre les résultats obtenus par simulation numérique pour le premier procédé selon l'invention, dans le cadre du traitement d'une charge d'hydrocarbures 12 de débit massique égal à 666,7 t/h résultant de la distillation atmosphérique d'un brut de type « OURAL ». Le fluide d'épuisement est du kérosène issu d'une distillation atmosphérique ayant un point de coupe TBP 145°C-230°C, un poids moléculaire de 152 g/mol et une densité à 15°C de 0.781.Table 1 below illustrates the results obtained by numerical simulation for the first process according to the invention, within the framework of the treatment of a hydrocarbon charge 12 with a mass flow rate equal to 666.7 t / h resulting from the distillation atmospheric of a “OURAL” type of crude. The exhaustion fluid is kerosene from from an atmospheric distillation having a TBP cutting point 145 ° C-230 ° C, a molecular weight of 152 g / mol and a density at 15 ° C of 0.781.

Les résultats obtenus sont comparés à ceux d'un procédé de l'état de la technique, dans lequel le fluide d'épuisement est de la vapeur d'eau, l'installation étant dépourvue de séparateur aval 38 et de pompe de recyclage 40. Tableau 1 Etat de la technique Figure 1 Gain Conditions d'opération Pression d'opération de la colonne 16 mbars (mmHg) 72 (54) 27 (20) Pression d'introduction du courant 50 dans la zone de flash mbars (mmHg) 105 (79) 50 (37,5) Pression en sortie de l'échangeur 32 mbars (mmHg) 60 (45) 15 (11) Température en sortie de l'échangeur 32 °C 33,5 33,5 Bilan de matière Débit de vapeur d'épuisement dans la colonne 16 t/h 33,5 - Débit total de kérosène dans les flux 52 + 119 t/h - 115 Débit de flux gazeux 82 t/h 8,3 5,7 - 31% Débit du courant 160 t/h 46,9 46,9 = Débit du courant 170 t/h 302,2 302,2 = Débit du courant 180 t/h 115,7 115,7 = Conception des équipements Aire des échangeurs 30 m2 3480 1360 - 61% Aire des échangeurs 32 m2 4 x 1220 2 x 1150 - 53% Débit d'eau de refroidissement t/h 4100 3545 - 13% Débit d'eau pour production de vapeur t/h 53,2 22,0 - 59% Gaz combustible (chauffage du four et production de vapeur) 99,6 102,1 + 2.5% Traitement final Débit du courant d'eau à traiter 100 t/h 53,3 22,4 - 62% The results obtained are compared with those of a process of the state of the art, in which the exhausting fluid is water vapor, the installation being devoid of downstream separator 38 and of recycling pump 40. <b> Table 1 </b> State of the art Figure 1 Gain Operating conditions Column 16 operating pressure mbar (mmHg) 72 (54) 27 (20) Current introduction pressure 50 in the flash zone mbar (mmHg) 105 (79) 50 (37.5) Pressure at exchanger outlet 32 mbar (mmHg) 60 (45) 15 (11) Temperature at the outlet of the heat exchanger 32 ° C 33.5 33.5 Material balance Depletion steam flow in column 16 t / h 33.5 - Total kerosene flow in flows 52 + 119 t / h - 115 Gas flow rate 82 t / h 8.3 5.7 - 31% Current flow 160 t / h 46.9 46.9 = Current flow 170 t / h 302.2 302.2 = Current flow 180 t / h 115.7 115.7 = Equipment design Exchanger area 30 m2 3480 1360 - 61% Exchanger area 32 m2 4 x 1220 2 x 1150 - 53% Cooling water flow t / h 4100 3545 - 13% Water flow for steam production t / h 53.2 22.0 - 59% Fuel gas (furnace heating and steam production) 99.6 102.1 + 2.5% Final processing Flow of water stream to be treated 100 t / h 53.3 22.4 - 62%

La présence d'un fluide d'épuisement facilement condensable assure un débit vers le groupe de vide 34 beaucoup moins consommateur en vapeur motrice 150, ce qui limite fortement la consommation globale de vapeur d'eau.The presence of an easily condensable exhaust fluid ensures a flow rate towards the vacuum group 34 which consumes considerably less driving steam 150, which greatly limits the overall consumption of steam.

De même, les températures sont plus élevées en tête de colonne 16, ce qui permet une température du flux 74 plus élevée que dans un schéma conventionnel. La viscosité du flux 74 est alors diminuée, réduisant la taille du premier échangeur thermique à air 30.Likewise, the temperatures are higher at the top of the column 16, which allows a temperature of the flow 74 higher than in a conventional scheme. The viscosity of the flow 74 is then reduced, reducing the size of the first air heat exchanger 30.

De même la taille de l'échangeur thermique aval 32 est réduite du fait qu'il n'y a plus de vapeur d'eau à condenser.Likewise, the size of the downstream heat exchanger 32 is reduced because there is no longer any water vapor to condense.

Par ailleurs, l'utilisation d'un fluide d'épuisement autre que la vapeur d'eau limite la quantité d'eau à traiter 100 récupérée dans la capacité 36.Furthermore, the use of an exhausting fluid other than water vapor limits the amount of water to be treated 100 recovered in capacity 36.

Une partie 119 du flux de fluide d'entrainement 52 est dérivée dans la charge 12 avant son passage dans le four 14 ou lors de ce passage.A portion 119 of the flow of drive fluid 52 is derived in the load 12 before its passage through the oven 14 or during this passage.

Une deuxième installation 130 selon l'invention est illustrée sur la figure 2. La deuxième installation 130 est destinée à la mise en œuvre d'un deuxième procédé de distillation sous vide selon l'invention.A second installation 130 according to the invention is illustrated on the figure 2 . The second installation 130 is intended for the implementation of a second vacuum distillation process according to the invention.

À la différence de la première installation 10, l'échangeur thermique aval 32 de la deuxième installation 130 est disposé directement dans la colonne de distillation 16, au niveau de la tête de la colonne, au-dessus du lit supérieur 43 associé au soutirage supérieur 30. L'échangeur thermique aval 32 est ici un échangeur thermique à plaques à faible perte de charge (typiquement inférieure à 7 mbars (5 mmHg), notamment de l'ordre de 1,3 mbars (1 mmHg)).Unlike the first installation 10, the downstream heat exchanger 32 of the second installation 130 is disposed directly in the distillation column 16, at the head of the column, above the upper bed 43 associated with the upper withdrawal. 30. The downstream heat exchanger 32 is here a plate heat exchanger with low pressure drop (typically less than 7 mbar (5 mmHg), in particular of the order of 1.3 mbar (1 mmHg)).

À la différence du procédé représenté sur la figure 1, les vapeurs de tête formant le courant de tête 80 issu de la distillation dans la colonne de distillation sous vide 16 pénètrent dans l'échangeur thermique 32 au sein de la colonne de distillation sous vide 16, par le haut. Le courant de tête 80 se condense dans l'échangeur thermique 32.Unlike the process shown in the figure 1 , the overhead vapors forming the overhead stream 80 from the distillation in the vacuum distillation column 16 penetrate into the heat exchanger 32 within the vacuum distillation column 16 from above. The overhead current 80 condenses in the heat exchanger 32.

Comme précédemment, un flux gazeux 82 est extrait de l'échangeur thermique 32, pour être amené vers l'unité de génération de vide 34 et un flux liquide de pied 84 est récupéré au bas de l'échangeur thermique 32, pour être amené dans le séparateur aval 38.As before, a gas flow 82 is extracted from the heat exchanger 32, to be brought to the vacuum generation unit 34 and a bottom liquid flow 84 is recovered at the bottom of the heat exchanger 32, to be brought into the downstream separator 38.

Le tableau ci-dessous illustre les résultats obtenus pour le second procédé selon l'invention, dans le cadre du traitement d'une charge d'hydrocarbures 12 de débit massique égal à 666,7 t/h, résultant de la distillation atmosphérique d'un brut de type « OURAL ». Le fluide d'épuisement est du kérosène issu d'une distillation atmosphérique ayant un point de coupe TBP 145°C - 230°C, un poids moléculaire de 152 g/mol et une densité à 15°C de 0,781.The table below illustrates the results obtained for the second process according to the invention, within the framework of the treatment of a hydrocarbon charge 12 with a mass flow rate equal to 666.7 t / h, resulting from the atmospheric distillation of a “OURAL” type of rough. The exhaustion fluid is kerosene from an atmospheric distillation having a TBP cutting point 145 ° C - 230 ° C, a molecular weight of 152 g / mol and a density at 15 ° C of 0.781.

Les résultats obtenus sont comparés à un procédé de l'état de la technique, dans lequel le fluide d'épuisement est de la vapeur, l'installation étant dépourvue de séparateur aval 38 et de pompe de recyclage 40. TABLEAU 2 Etat de la technique Figure 2 Gain Conditions d'opération Pression d'opération de la colonne 16 mbars (mmHg) 72 (54) 17 (12.5) Pression d'introduction dans la zone de flash du courant 54 mbars (mmHg) 105 (79) 40 (30) Pression en sortie de l'échangeur 32 mbars (mmHg) 60 (45) 15 (11) Température en sortie de l'échangeur 32 °C 33,5 30 Bilan de matière Débit de vapeur d'épuisement dans la colonne 16 t/h 33,5 - Débit total de kérosène dans les flux 52+119 t/h - 65 Débit de flux gazeux 82 t/h 8,3 5.2 - 37% Débit du courant 160 t/h 46,9 46.9 = Débit du courant 170 t/h 302,2 302.2 = Débit du courant 180 t/h 115,7 115.7 = Conception des équipements Aire des échangeurs 30 m2 3480 1683 - 52% Aire des échangeurs 32 m2 4 x 1220 2475 - 49% Débit d'eau de refroidissement t/h 4100 2423 - 41% Débit d'eau pour production de vapeur t/h 53,2 21.8 - 59% Gaz combustible (chauffage du four et production de vapeur) 99,6 95.5 - 4% Traitement final Débit de courant 100 t/h 53,3 22.2 - 63% The results obtained are compared to a process of the prior art, in which the exhausting fluid is steam, the installation being devoid of downstream separator 38 and of recycling pump 40. <b> TABLE 2 </b> State of the art Figure 2 Gain Operating conditions Column 16 operating pressure mbar (mmHg) 72 (54) 17 (12.5) Input pressure in the flash zone of the current 54 mbar (mmHg) 105 (79) 40 (30) Pressure at exchanger outlet 32 mbar (mmHg) 60 (45) 15 (11) Temperature at the outlet of the heat exchanger 32 ° C 33.5 30 Material balance Depletion steam flow in column 16 t / h 33.5 - Total kerosene flow in flows 52 + 119 t / h - 65 Gas flow rate 82 t / h 8.3 5.2 - 37% Current flow 160 t / h 46.9 46.9 = Current flow 170 t / h 302.2 302.2 = Current flow 180 t / h 115.7 115.7 = Equipment design Exchanger area 30 m2 3480 1683 - 52% Exchanger area 32 m2 4 x 1220 2475 - 49% Cooling water flow t / h 4100 2423 - 41% Water flow for steam production t / h 53.2 21.8 - 59% Fuel gas (furnace heating and steam production) 99.6 95.5 - 4% Final processing Current flow 100 t / h 53.3 22.2 - 63%

À la différence du procédé représenté sur la figure 1, le procédé illustré sur la figure 2 présente une pression en tête de colonne encore plus basse, par exemple inférieure à 27 mbars (20 mmHg), et notamment comprise entre 13 mbars (10 mmHg) et 20 mbars (15 mmHg).Unlike the process shown in the figure 1 , the process illustrated in figure 2 has an even lower pressure at the top of the column, for example less than 27 mbar (20 mmHg), and in particular between 13 mbar (10 mmHg) and 20 mbar (15 mmHg).

A performances identiques aux performances de la figure 10 (taux de récupération du distillat sous vide lourd identique), ce schéma réduit le flux de fluide d'épuisement 52 nécessaire, tout en conservant une surface d'échange thermique réduite dans l'échangeur thermique aval 32, et dans les échangeurs 30.At performances identical to the performances of FIG. 10 (recovery rate of the distillate under identical heavy vacuum), this diagram reduces the flow of exhausting fluid 52 necessary, while retaining a reduced heat exchange surface in the downstream heat exchanger 32, and in the exchangers 30.

La quantité de fluide d'épuisement injectée dans la colonne de distillation sous vide 16 étant réduite, la consommation de gaz combustible destinée à la vaporisation du fluide d'épuisement est ainsi réduite, ce qui diminue notablement la consommation globale de gaz combustible.The quantity of exhaustion fluid injected into the vacuum distillation column 16 being reduced, the consumption of combustible gas intended for the vaporization of the exhaustion fluid is thus reduced, which significantly reduces the overall consumption of combustible gas.

La consommation d'eau de refroidissement est en outre encore réduite, compte tenu de la plus faible quantité de fluide d'épuisement à condenser dans l'échangeur thermique 32.The consumption of cooling water is also further reduced, given the lower quantity of exhaustion fluid to be condensed in the heat exchanger 32.

Dans une variante (non représentée), l'échangeur 32 est situé à l'extérieur de la colonne de distillation 16. Les performances de cette variante se situent entre les performances obtenues avec l'installation représentée sur la figure 1 et les performances obtenues avec l'installation représentée sur la figure 2.In a variant (not shown), the exchanger 32 is located outside of the distillation column 16. The performances of this variant lie between the performances obtained with the installation shown on the figure 1 and the performance obtained with the installation shown on the figure 2 .

Une troisième installation 140 selon l'invention est illustrée par la figure 3. À la différence de la deuxième installation 130 représentée sur la figure 2, l'installation 140 comporte un deuxième échangeur thermique aval 142 disposé en aval du premier échangeur thermique aval 32 situé dans la colonne de distillation sous vide 16. Le deuxième échangeur thermique aval 142 est disposé hors de la colonne de distillation sous vide 16, et reçoit le flux gazeux 82 provenant du premier échangeur thermique aval 32.A third installation 140 according to the invention is illustrated by the figure 3 . Unlike the second installation 130 represented on the figure 2 , the installation 140 comprises a second downstream heat exchanger 142 disposed downstream of the first downstream heat exchanger 32 located in the vacuum distillation column 16. The second downstream heat exchanger 142 is disposed outside of the vacuum distillation column 16, and receives the gas flow 82 from the first downstream heat exchanger 32.

Le deuxième échangeur thermique aval 142 est un échangeur thermique à plaques et à faible perte de charge (typiquement inférieure à 7 mbars (5 mmHg), notamment de l'ordre de 1,3 mbars (1 mmHg)). Il est ici muni d'une rampe 143 de pulvérisation d'un courant d'hydrocarbures liquides 144, typiquement d'un courant provenant de l'installation de distillation atmosphérique. Le courant d'hydrocarbures liquides 144 est par exemple un courant de distillat lourd atmosphérique (« HAGO » ou « Heavy Atmospheric Gas Oil » en anglais).The second downstream heat exchanger 142 is a plate heat exchanger with low pressure drop (typically less than 7 mbar (5 mmHg), in particular of the order of 1.3 mbar (1 mmHg)). It is here provided with a boom 143 for spraying a stream of liquid hydrocarbons 144, typically a stream coming from the atmospheric distillation installation. The stream of liquid hydrocarbons 144 is for example an atmospheric heavy distillate stream (“HAGO” or “Heavy Atmospheric Gas Oil” in English).

Le troisième procédé de distillation sous vide selon l'invention diffère du deuxième procédé en ce que le flux de tête 82 produit dans le premier échangeur thermique aval 32 est introduit dans le deuxième échangeur thermique 142. Le flux de tête 82 est au moins partiellement condensé d'une part, grâce à l'absorption générée par l'introduction du fluide 144, et d'autre part, par échange thermique avec l'eau.The third vacuum distillation process according to the invention differs from the second process in that the overhead flow 82 produced in the first downstream heat exchanger 32 is introduced into the second heat exchanger 142. The head flow 82 is at least partially condensed on the one hand, thanks to the absorption generated by the introduction of the fluid 144, and on the other hand, by heat exchange with the water.

Un condensat additionnel 146 est produit au pied du deuxième échangeur thermique aval 142, le reste du flux gazeux 82 étant introduit dans l'unité de génération de vide 34, comme décrit précédemment. Le condensat additionnel est collecté dans la capacité 36.An additional condensate 146 is produced at the foot of the second downstream heat exchanger 142, the rest of the gas flow 82 being introduced into the vacuum generation unit 34, as described above. The additional condensate is collected in capacity 36.

Le tableau ci-dessous illustre les résultats obtenus pour le troisième procédé selon l'invention, dans le cadre du traitement d'une charge d'hydrocarbures 12 de débit massique égal à 666,7 t/h résultant de la distillation atmosphérique d'un brut de type « OURAL ». Le fluide d'épuisement est du kérosène.The table below illustrates the results obtained for the third process according to the invention, in the context of the treatment of a hydrocarbon charge 12 with a mass flow rate equal to 666.7 t / h resulting from the atmospheric distillation of a "OURAL" type raw. The exhaustion fluid is kerosene.

Les résultats obtenus sont comparés à un procédé de l'état de la technique, dans lequel le fluide d'épuisement est de la vapeur, l'installation étant dépourvue de séparateur aval 38 et de pompe de recyclage 40. TABLEAU 3 Etat de la technique Figure 3 Gain Conditions d'opération Pression d'opération de la colonne 16 mbars (mmHg) 72 (54) 17 (12.5) Pression d'introduction dans la zone de flash du courant 50 mbars (mmHg) 105 (79) 40 (30) Pression en sortie de l'échangeur 32 mbars (mmHg) 60 (45) 15 (11) Température en sortie de l'échangeur 32 °C 33,5 30 Bilan de matière Débit de vapeur d'épuisement t/h 33,5 - Débit total de kérosène dans les courants 52+119 t/h - 65 Débit de flux gazeux 82 t/h 8,3 3,3 - 60% Débit du courant 160 t/h 46,9 46,9 = Débit du courant 170 t/h 302,2 302,2 = Débit du courant 180 t/h 115,7 115,7 = Conception des équipements Aire des échangeurs 30 m2 3480 1683 - 52% Aire des échangeurs 32, 142 m2 4 x 1220 2475+ 302 - 42% Débit d'eau de refroidissement t/h 4100 2493 - 39% Débit d'eau pour production de vapeur t/h 53,2 18,7 - 65% Gaz combustible (chauffage du four et production de vapeur) 99,6 93,7 - 6% Traitement final Débit de courant 100 t/h 53,3 19,1 - 68% The results obtained are compared to a process of the prior art, in which the exhausting fluid is steam, the installation being devoid of downstream separator 38 and of recycling pump 40. <b> TABLE 3 </b> State of the art Figure 3 Gain Operating conditions Column 16 operating pressure mbar (mmHg) 72 (54) 17 (12.5) Input pressure in the flash zone of the current 50 mbar (mmHg) 105 (79) 40 (30) Pressure at exchanger outlet 32 mbar (mmHg) 60 (45) 15 (11) Temperature at the outlet of the heat exchanger 32 ° C 33.5 30 Material balance Depletion steam flow t / h 33.5 - Total kerosene flow in streams 52 + 119 t / h - 65 Gas flow rate 82 t / h 8.3 3.3 - 60% Current flow 160 t / h 46.9 46.9 = Current flow 170 t / h 302.2 302.2 = Current flow 180 t / h 115.7 115.7 = Equipment design Exchanger area 30 m2 3480 1683 - 52% Exchanger area 32, 142 m2 4 x 1220 2475+ 302 - 42% Cooling water flow t / h 4100 2493 - 39% Water flow for steam production t / h 53.2 18.7 - 65% Fuel gas (furnace heating and steam production) 99.6 93.7 - 6% Final processing Current flow 100 t / h 53.3 19.1 - 68%

Le troisième procédé selon l'invention réduit encore la consommation de vapeur de l'unité de génération de vide 34. Ainsi, la consommation globale de combustible dans le procédé est encore réduite, de même que la quantité d'eau à traiter 100 produite.The third method according to the invention further reduces the steam consumption of the vacuum generation unit 34. Thus, the overall consumption of fuel in the process is further reduced, as well as the quantity of water to be treated 100 produced.

Comme indiqué précédemment, les procédés selon l'invention réduisent considérablement la consommation en utilités, notamment en eau de refroidissement et en vapeur d'eau, ce qui diminue les coûts d'exploitation de l'installation, tout en conservant un procédé permettant d'atteindre des performances ambitieuses de taux de récupération de distillats sous vide.As indicated previously, the methods according to the invention considerably reduce the consumption of utilities, in particular of cooling water and in water vapor, which reduces the operating costs of the installation, while retaining a process which makes it possible to achieve ambitious performances of recovery rate of distillates under vacuum.

Dans le procédé selon l'invention, et comme indiqué plus haut, le débit de courant d'apport 118 en fluide d'épuisement peut être contrôlé indépendamment de la nature et du débit de la charge 12, et indépendamment du débit de courant de recyclage 114. Ce dernier permettant de fournir la quantité et la qualité de fluide d'épuisement 52 nécessaire à la qualité de distillation.In the method according to the invention, and as indicated above, the flow rate of supply current 118 in exhaustion fluid can be controlled independently of the nature and flow rate of the charge 12, and independently of the flow rate of recycling current 114. The latter making it possible to supply the quantity and the quality of exhaustion fluid 52 necessary for the quality of distillation.

Avantageusement, le rapport entre le débit massique du fluide d'épuisement 52 introduit dans la colonne de distillation sous vide 16 et le débit massique du courant de fond net 190 récupéré au fond de la colonne de distillation sous vide 16 (après dérivation d'un courant de trempe renvoyé vers la colonne de distillation sous vide 16) est supérieur à 80 kg de fluide d'épuisement pour 1000 kg de courant de fond net récupéré au fond de la colonne de distillation sous vide 16 et est notamment compris entre 80 kg et 800 kg de fluide d'épuisement pour 1000 kg de courant de fond net récupéré au fond de la colonne de distillation sous vide 16.Advantageously, the ratio between the mass flow rate of the exhausting fluid 52 introduced into the vacuum distillation column 16 and the mass flow rate of the net bottom stream 190 recovered from the bottom of the vacuum distillation column 16 (after derivation of a quenching current returned to the vacuum distillation column 16) is greater than 80 kg of exhaustion fluid per 1000 kg of net bottom current recovered at the bottom of the vacuum distillation column 16 and is in particular between 80 kg and 800 kg of exhaustion fluid for 1000 kg of net bottom current recovered from the bottom of the vacuum distillation column 16.

En outre, la qualité du fluide d'épuisement 52 utilisé, constitué d'un mélange d'hydrocarbures présentant une température moyenne d'ébullition pondérée (Tmav) comprise entre 150°C et 250°C avantageusement entre 190°C et 210°C, est parfaitement maitrisée dans le procédé selon l'invention.In addition, the quality of the depletion fluid 52 used, consisting of a mixture of hydrocarbons having a weighted average boiling temperature (Tmav) of between 150 ° C and 250 ° C advantageously between 190 ° C and 210 ° C , is perfectly mastered in the process according to the invention.

Un tel fluide est optimal puisqu'il assure un épuisement efficace de la charge 12, tout en étant facilement condensable à pression très faible en tête de la colonne de distillation sous vide 16, et donc recyclable à travers le courant liquide 114.Such a fluid is optimal since it ensures efficient exhaustion of the charge 12, while being easily condensable at very low pressure at the top of the vacuum distillation column 16, and therefore recyclable through the liquid stream 114.

Le fluide 52 présente l'avantage d'être presque totalement récupéré dans le courant de tête de colonne 80. Ceci permet le recyclage et évite l'extraction de fluide d'épuisement 52 dans les courants de distillat 160, 170, 180 en particulier dans le courant 160 de distillat léger sous vide.The fluid 52 has the advantage of being almost completely recovered in the column head stream 80. This allows recycling and avoids the extraction of exhaustion fluid 52 in the distillate streams 160, 170, 180 in particular in stream 160 of light vacuum distillate.

Avantageusement, plus de 95 % en masse du fluide d'épuisement 52 introduit dans la colonne de distillation sous vide 16 est récupéré de la colonne de distillation sous vide 16 dans le flux 112 via le courant de tête de colonne 80 après condensation.Advantageously, more than 95% by mass of the exhausting fluid 52 introduced into the vacuum distillation column 16 is recovered from the vacuum distillation column 16 in the stream 112 via the column head stream 80 after condensation.

Ainsi, il n'est pas nécessaire d'introduire de la vapeur en complément dans le fluide d'épuisement 52, ce qui limite la pression dans la colonne de distillation sous vide 16, ce qui permet de réduire la consommation en utilités et de réduire la taille de certains équipements tout en obtenant un épuisement optimal de la charge 12.Thus, it is not necessary to introduce additional steam into the exhausting fluid 52, which limits the pressure in the vacuum distillation column 16, which makes it possible to reduce the consumption of utilities and to reduce the size of certain equipment while obtaining optimum depletion of the load 12.

Claims (13)

  1. Method for the vacuum distillation of a hydrocarbon feedstock (12) comprising the following steps:
    - heating the feedstock (12);
    - introducing the feedstock (12) into a flash zone (N1) of a vacuum distillation column (16);
    - removing at least one distillate stream (58, 64, 70) at an intermediate level (N3, N4, N5) from the vacuum distillation column (16);
    - withdrawing a column head stream (80) at the head of the vacuum distillation column (16);
    - partially condensing the column head stream (80) to recover a liquid flow (84) and a gaseous flow (82);
    - passing the gaseous flow (82) through a vacuum generation unit (34) and recovering at least one condensate (86, 90, 96) and a gaseous fraction of non-condensable gas (94);
    the method comprising introducing into the vacuum distillation column (16) a flow (52) of a feedstock-stripping fluid (12), characterized in that the stripping fluid consists of a hydrocarbon mixture having a weighted average boiling temperature (Tmav) of between 150°C and 250°C, preferably between 190°C and 210°C.
  2. Method according to claim 1, wherein the stripping fluid consists of kerosene.
  3. Method according to any one of the claims 1 or 2, comprising a step of forming a stripping fluid recycling stream (114) from the liquid flow (84).
  4. Method according to claim 3, comprising removing a purging stream (116) from a portion of the stripping fluid in the stripping fluid recycling stream (114), and introducing a supplementary stripping fluid flow (118) downstream of the purging stream (116) removing, wherein the stripping fluid recycling stream (114) forms at least a portion of the stripping fluid flow (52).
  5. Method according to claim 1 or 2, wherein the stripping fluid consists entirely of a supplementary stream (118), wherein no stream coming from the liquid flow (84) is recycled into the stripping fluid flow (52) introduced into the vacuum distillation column (16).
  6. Method according to any of the preceding claims, comprising introducing the heated stripping fluid flow (54) into the vacuum distillation column (16) at a level (N2) located below the level (N1) of introduction of the feedstock (12).
  7. Method according to claim 6, comprising the derivation of a portion (119) of the stripping fluid flow (52), before its introduction into the vacuum distillation column (16), and its introduction into the feedstock (12).
  8. Method according to any one of the preceding claims, wherein the step of condensing the column head stream (80) is implemented in a first downstream heat exchanger (32), preferably a plate heat exchanger, in particular with a low pressure loss, wherein the first downstream heat exchanger (32) is arranged in the vacuum distillation column (16), or outside the vacuum distillation column (16).
  9. Method according to any one of the preceding claims, wherein the step of condensing the column head stream (80) is implemented in a first downstream heat exchanger (32), preferably a plate heat exchanger, in particular with a low pressure loss, wherein the method comprises a step of passing the gaseous flow (82) from the first downstream heat exchanger (32) to a second downstream heat exchanger (142) in order to obtain an additional condensate (146).
  10. Method according to claim 9, wherein the step of passing the gaseous flow (82) into the second downstream heat exchanger (142) comprises spraying a liquid hydrocarbon stream (144) into the gaseous flow (82).
  11. Method according to any one of the preceding claims, comprising a step of recovering the or each condensate (86, 90, 96) in a volume (36), and recovering a stream of water to be treated (100) and a recovered hydrocarbon stream (98) in the volume (36).
  12. Method according to any one of the preceding claims, wherein the step of passing the gaseous flow (82) through a vacuum generation unit (34) comprises introducing the gaseous flow into at least one steam ejector (45) to form an ejected stream, and partially condensing the ejected stream produced by each steam ejector (45) in a condenser (46).
  13. Method according to any one of the preceding claims, comprising completely vaporizing and superheating the stripping fluid (52) before introducing it at the bottom of vacuum distillation column (16).
EP16759779.8A 2015-09-01 2016-09-01 Method for the vacuum distillation of a hydrocarbon feed stock Active EP3344732B1 (en)

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FR1558097A FR3040311B1 (en) 2015-09-01 2015-09-01 PROCESS FOR VACUUM DISTILLATION OF A HYDROCARBON FILLER AND ASSOCIATED INSTALLATION
PCT/EP2016/070614 WO2017037174A1 (en) 2015-09-01 2016-09-01 Method for the vacuum distillation of a hydrocarbon feedstock and associated facility

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WO2022029487A1 (en) * 2020-08-07 2022-02-10 Carbovate Development Corp. Hydrocarbon stream separation system and method
US20240026227A1 (en) * 2022-07-18 2024-01-25 Engineers India Limited Improved configuration of vacuum distillation unit and process for separating components of reduced crude oil

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US1843520A (en) * 1924-05-05 1932-02-02 Standard Oil Co Art of distilling oils
US2853439A (en) * 1952-08-01 1958-09-23 Exxon Research Engineering Co Combination distillation and hydrocarbon conversion process
US3110663A (en) * 1959-12-30 1963-11-12 Gulf Oil Corp Process and apparatus for distilling and visbreaking reduced crude
US4261814A (en) * 1977-11-30 1981-04-14 Exxon Research And Engineering Co. Vacuum pipestill operation
US5167773A (en) * 1990-01-16 1992-12-01 Exxon Research And Engineering Co. Distillation tower and sidestream stripper therefor
US5858213A (en) * 1996-07-30 1999-01-12 Exxon Research And Engineering Company Monitoring for coke formation during hydrocarbon feed processing
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EP3344732A1 (en) 2018-07-11
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