APPARATUS AND METHOD FOR CONDUCTING A FISCHER-TROPSCH SYNTHESIS REACTION

Description

[0001] The present invention relates to an apparatus and method for conducting an F-T synthesis reaction and is particularly concerned with recovering condensable products in the top gas stream from an F-T reactor. WO 2008/062208 discloses an apparatus and a method for conducting a Fischer-Tropsch synthesis reaction. The F-T synthesis process is used for converting natural gas, coal or biomass via a syngas unit, into longer chain hydrocarbon waxes. One problem associated with the F-T system is fouling of heat exchangers and other equipment down stream of the reactor gas outlet by the precipitation of higher boiling products in solid form on cold surfaces.

[0002] It is an object of the present invention to address this difficulty.

[0003] According to one aspect of the invention, there is provided a process for recovering condensable products contained within an outlet gas stream from a Fischer- Tropsch reactor, comprising the steps: conveying the reactor gas stream to a condensation and separation unit; subjecting the F-T gases to direct heat exchange in the condensation and separation unit against a stream of evaporable hydrocarbon liquid, thereby cooling the F-T gases; condensing higher boiling components in the F-T gases; separating the condensed higher boiling components from gaseous components; and removing a gaseous fraction and a condensed higher boiling fraction; in which the gaseous fraction obtained from the removing step is subjected to a first separation step in which it is separated into a gas phase, a liquid hydrocarbon phase and an aqueous phase. At least a portion of the liquid hydrocarbon phase from the first separation step constitutes the evaporable hydrocarbon liquid conveyed to the separation unit.

[0004] According to another aspect of the invention, there is provided an apparatus for recovering condensable products contained within an outlet gas stream from a Fischer-Tropsch reactor, comprising a Fischer-Tropsch reactor; a condensation and separation unit; a gas/liquid separator; a line arranged to convey the reactor gas stream to the condensation and separations unit; a condensed higher boiling fraction outlet from the condensation and separation unit; a gaseous fraction outlet line from the condensation and separation unit arranged to convey at least a portion of the gaseous fraction to the gas/liquid separator; and a recycle line arranged to convey evaporable hydrocarbon liquid from the gas/liquid separator to the condensation and separation unit, thereby subjection the reactor gas stream to direct heat exchange in the condensation and separation unit against the stream of evaporable hydrocarbon liquid.

[0005] Thus, waxy material which might otherwise foul downstream equipment is removed from the overhead gas stream from the reactor by direct heat exchange with a liquid obtained from the lighter fractions of the gas stream.

[0006] Preferably, the reactor gas stream is pre-cooled in order to produce a mixture of gaseous and liquid components before it is conveyed to the condensation and separation unit. Preferably, the pre-cooling comprises indirect heat exchange between the reactor gas stream and a syngas feed stream to the reactor. As mentioned above, the gaseous fraction obtained from the removing step is subjected to a first separation step in which it is separated into a gas phase, a liquid hydrocarbon phase and an aqueous phase. (It will be understood that there will inevitably be a small amount of water in the hydrocarbon phase and vice- versa.) Preferably, prior to the first separation step, the gaseous fraction is subjected to a cooling step to form a stream of gas and liquid products.

[0007] Preferably, the higher boiling fraction removed from the condensation and separation unit is a heavy oil and the liquid hydrocarbon phase from the separation step is a light oil. The products received at the highest temperature (typically in the range 110 - 150 degrees C) are referred to as "Heavy Oil" (HO), while product recovered at the lowest temperature (defined by the availability of cooling water) and at typically 30 - 50 degrees C, are referred to as "Light Oil" (LO).

[0008] Preferably, the gas phase from the first separation step is subjected to a second separation step in which it is separated into a gas phase, a liquid hydrocarbon phase and an aqueous phase. Preferably, prior to the second separation step, the gas phase from the first separation step is subjected to a cooling step to form a second stream of gas and liquid products. However, while product recovery has been described as being achieved in two cooling steps, there could be only one, or several such steps.

[0009] Preferably, the condensation and separation unit is a liquid wash column. Preferably, the reactor is a slurry bubble column reactor. Preferably, the gas/liquid separator is a liquid flash tank. The apparatus may further include a heat exchanger facilitating indirect heat exchange between the reactor gas stream and a syngas feed stream to the reactor and a second gas/liquid separator arranged to receive a gas stream from the first gas/liquid separator. Preferably, the second gas/liquid separator is a liquid flash tank.

[0010] Thus, the present invention may be considered to reside in the use of the liquid wash column where recycled LO is utilised to condense the HO products, while LO is vaporised in a column. The cooling duty to condense HO is scuffed into the cold section with the recycled LO. This design will reduce the partial pressure of heavy components into the cold section of the product recovery section.

[0011] The invention may also be considered to reside in a general non-cryogenic process for the recovery of condensable hydrocarbon components included in a blend of hydrocarbons that may pose a risk of fouling by precipitation of components having a melting point above ambient temperatures (approx. 20°C) though direct heat-exchange against a stream of evaporable hydrocarbon liquids in a condensation and separation zone and recovery of a liquid fraction of higher-boiling hydrocarbons and a gaseous fraction, from which one or more fractions of lower-boiling hydrocarbons are obtained by subsequent processing of the gaseous fraction. Typically, the condensable hydrocarbon components have boiling points in the ranges corresponding to those of light and heavy oil.

[0012] The invention also extends to a process from conducting an F-T synthesis reaction adopting the aspects of the invention set out above, in which H₂ and CO are supplied to the F-T reactor and a wax product stream is recovered from the reactor.

[0013] Preferably, the reaction is carried out in a slurry bubble column reactor, in which the H₂ and CO are supplied to a slurry in the reactor, the slurry comprising the catalyst in suspension in a liquid including the reaction products of the H₂ and CO, the catalyst being maintained in suspension in the slurry at least partly by the motion of the gas supplied to the slurry. Preferably, the reaction temperature is in the range 190 - 250°C and/or the reaction pressure is in the range 10 - 60 bar. Preferably, the H₂/CO ratio of the gases supplied to the Fischer-Tropsch synthesis reactor is in the range 1.1 to 2.2. Preferably, the superficial gas velocity in the reactor is in the range 5 to 60 cm/s. Preferably, the product of the Fischer-Tropsch synthesis reaction is subsequently subjected to post-processing, such as de-waxing, hydro-isomerisation, hydro-cracking, and combinations of these.

[0014] The invention may be carried into practice in various ways and one embodiment will now be described by way of example, with reference to the accompanying drawings in which:-

Figure 1 is a simplified flow diagram of a Fischer-Tropsch synthesis installation embodying the present invention.

[0015] The F-T installation comprises a syngas unit 11, an F-T slurry reactor 12, a liquid wash tank or column 13, first and second flash and separator tanks 14, 15 and a optional cryogenic tail gas recovery unit 16.

[0016] Natural gas 17, oxygen 18 and steam 19 are fed to the syngas unit 11 where syngas is produced in the conventional manner and leaves as a syngas outlet stream 21. Water is removed in a water recovery stream 22 and directed to a utility system (not shown). The syngas stream 21 is combined with a portion 23 of a gas recycle stream 29 from the tail gas recovery unit 16, and the combined gas stream 24 is heated in a first heat exchanger 25. The combined stream is then fed to the F-T reactor 12 in a line 26 via a second heat exchanger 27 in which it is further heated to about 150°C by indirect heat exchange with an overhead gas stream 28 leaving the F-T reactor 12 at about 190 - 250°C. Of the remainder of the gas recycle stream 29, a portion 31 may be purged to a fuel gas system, and a portion 32 is recycled to the syngas unit 11.

[0017] The syngas is converted in the F-T reactor 12 to a wide boiling point range of hydrocarbons. Those hydrocarbons that are in the liquid phase at reactor conditions are extracted as liquid and referred to as 'wax' (since a substantial portion of the product would normally be solid at ambient temperatures). They are removed from the reactor 12 in a wax product line 33.

[0018] To avoid fouling of heat exchangers down stream of the reactor top gas outlet by the precipitation of solid matter on cold surfaces, the overhead gas stream 28, which also contains hydrocarbon products that are solid at lower temperatures is fed to the wash tank 13. After heat exchange with the syngas stream 24 in the heat exchanger 27, the overhead stream 28 is a mixed stream of gas and liquid components. An evaporable light oil stream 34 is fed to the wash tank 13, which condenses heavy oil (which may contain significant amounts of wax components) from the overhead gas stream 28. The heavy oil is removed from the wash tank 13 in a heavy oil outlet stream 35. The feed streams 28, 34 to the wash tank 13 are controlled in such a way that water does not condense in the tank 13.

[0019] A gas stream 36 is removed from the wash tank 13 and cooled in a heat exchanger 37 to provide a three-phase stream of gas and liquid products with water. This is fed to the first flash and separator tank 14, from which water is recovered and removed in a water stream 38 and light oil is recovered and removed in a light oil stream 39. A portion of the light oil makes up the evaporable light oil stream 34 that is fed to the wash tank 13; thus the recycled light oil stream acts as a direct cooling medium on the F-T reactor top gas stream in the wash tank 13. The remainder of the light oil is removed in a light oil recovery stream 41.

[0020] The uncondensed product from the first flash tank 14 is removed in a gas stream 42 and is cooled in a heat exchanger 43 whereby more liquid products are condensed out and the resulting gas and liquid stream 44 is fed to the second flash and separator tank 15. Water is recovered and removed from the second flash tank 15 in a water stream 45 and light oil is recovered and removed in a light oil recovery stream 46.

[0021] Components that remain in the gas phase in the second flash tank 15 are removed as a tail gas stream 47. This may be treated in the tail gas recovery unit 16 to produce a LPG stream 48 and a C5+ stream 49 for upgrading.

Claims

1. A process for recovering condensable products contained within an outlet gas stream from a Fischer-Tropsch reactor, comprising the steps:

conveying the reactor gas stream to a condensation and separation unit;

subjecting the F-T gases to direct heat exchange in the condensation and separation unit against a stream of evaporable hydrocarbon liquid, thereby cooling the F-T gases;

condensing higher boiling components in the F-T gases;

separating the condensed higher boiling components from gaseous components; and removing a gaseous fraction and a condensed higher boiling fraction;

in which the gaseous fraction obtained from the removing step is subjected to a first separation step in which it is separated into a gas phase, a liquid hydrocarbon phase and an aqueous phase; and in which at least a portion of the liquid hydrocarbon phase from the first separation step constitutes the evaporable hydrocarbon liquid conveyed to the separation unit.

2. A process as claimed in Claim 1, in which the reactor gas stream is pre- cooled in order to produce a mixture of gaseous and liquid components before it is conveyed to the condensation and separation unit, and in which the pre-cooling may comprise indirect heat exchange between the reactor gas stream and a syngas feed stream to the reactor.

3. A process as claimed in Claim 1 or Claim 2, in which the operating parameters are controlled in order to avoid condensation of water in the condensation and separation unit.

4. A process as claimed in any preceding claim, in which prior to the first separation step, the gaseous fraction is subjected to a cooling step to form a stream of gas and liquid products.

5. A process as claimed in any preceding claim, in which the gas phase from the first separation step is subjected to a second separation step in which it is separated into a gas phase, a liquid hydrocarbon phase and an aqueous phase.

6. A process as claimed in Claim 5, in which, prior to the second separation step, the gas phase from the first separation step is subjected to a cooling step to form a second stream of gas and liquid products.

7. A process for conducting a Fischer-Tropsch synthesis reaction to produce Fischer-Tropsch wax which comprises supplying H₂ and CO to a Fischer-Tropsch reactor, conducting the process set out in any preceding claim, and removing a wax product stream from the reactor.

8. A process as claimed in Claim 7, in which the reaction is carried out in a slurry bubble column reactor, and in which the H₂ and CO are supplied to a slurry in the reactor, the slurry comprising catalyst in suspension in a liquid including the reaction products of the H₂ and CO, the catalyst being maintained in suspension in the slurry at least partly by the motion of the gas supplied to the slurry.

9. A process as claimed in Claim 8, in which the reaction temperature is in the range 190 - 250°C and/or the reaction pressure is in the range 10 - 60 bar, and/or the H₂/CO ratio of the gases supplied to the Fischer- Tropsch synthesis reactor is in the range 1.1 to 2.2., and/or the superficial gas velocity in the reactor is in the range 5 to 60 cm/s.

10. A process as claimed in any of Claims 8 to 9, in which the product of the Fischer-Tropsch synthesis reaction is subsequently subjected to post-processing, which may be selected from de-waxing, hydro-isomerisation, hydro-cracking, and combinations of these.

11. Apparatus for recovering condensable products contained within an outlet gas stream from a Fischer-Tropsch reactor, comprising a Fischer- Tropsch reactor; a condensation and separation unit; a gas/liquid separator; a line arranged to convey the reactor gas stream to the condensation and separations unit; a condensed higher boiling fraction outlet from the condensation and separation unit; a gaseous fraction outlet line from the condensation and separation unit arranged to convey at least a portion of the gaseous fraction to the gas/liquid separator; and a recycle line arranged to convey evaporable hydrocarbon liquid from the gas/liquid separator to the condensation and separation unit, thereby subjecting the reactor gas stream to direct heat exchange in the condensation and separation unit against the stream of evaporable hydrocarbon liquid.

12. Apparatus as claimed in Claim 11, in which the condensation and separation unit is a liquid wash column, and/or the reactor is a slurry bubble column reactor, and/or the gas/liquid separator is a liquid flash tank.

13. Apparatus as claimed in any of Claims 11 to 12, further including a heat exchanger facilitating indirect heat exchange between the reactor gas stream and a syngas feed stream to the reactor.

14. Apparatus as claimed in any of Claims 11 to 13, further including a second gas/liquid separator arranged to receive a gas stream from the first gas/liquid separator, and in which the second gas/liquid separator is a liquid flash tank.

Ansprüche

1. Verfahren zum Gewinnen kondensierbarer Produkte, die in einem Auslassgasstrom eines Fischer-Tropsch-Reaktors enthalten sind, umfassend die Schritte:

Zuführen des Reaktorgasstroms zu einer Kondensations- und Trenneinheit;

Unterwerfen der F-T-Gase an direkten Wärmetausch in der Kondensations- und Trenneinheit gegen einen Strom von verdampfbarer Kohlenwasserstoffflüssigkeit und dadurch Kühlen der F-T-Gase;

Kondensieren höhersiedender Komponenten der F-T-Gase;

Abtrennen der kondensierten höhersiedenden Komponenten von gasförmigen Komponenten;

und Abführen einer gasförmigen Fraktion und einer kondensierten höhersiedenden Fraktion;

wobei die bei dem Abführschritt erhaltene gasförmige Fraktion einem ersten Trennschritt unterworfen wird, bei dem sie in eine Gasphase, eine flüssige Kohlenwasserstoffphase und eine wässrige Phase aufgetrennt wird; und wobei wenigstens ein Teil der flüssigen Kohlenwasserstoffphase aus dem ersten Trennschritt die verdampfbare Kohlenwasserstoffflüssigkeit bildet, die der Trenneinheit zugeführt wird.

2. Verfahren gemäß Anspruch 1, wobei der Reaktorgasstrom vorgekühlt wird, um ein Gemisch von gasförmigen und flüssigen Komponenten zu erhalten, bevor er der Kondensations- und Trenneinheit zugeführt wird, und wobei das Vorkühlen indirekten Wärmetausch zwischen dem Reaktorgasstrom und einem dem Reaktor zugeführten Synthesegasstrom umfassen kann.

3. Verfahren gemäß Anspruch 1 oder Anspruch 2, wobei die Betriebsparameter gesteuert werden, um Kondensation von Wasser in der Kondensations- und Trenneinheit zu verhindern.

4. Verfahren gemäß einem der vorstehenden Ansprüche, wobei vor dem ersten Trennschritt die gasförmige Fraktion einem Kühlschritt unterworfen wird, um einen Strom von gasförmigen und flüssigen Produkten zu bilden.

5. Verfahren gemäß einem der vorstehenden Ansprüche, wobei die Gasphase aus dem ersten Trennschritt einem zweiten Trennschritt unterworfen wird, bei dem sie in eine Gasphase, eine flüssige Kohlenwasserstoffphase und eine wässrige Phase aufgetrennt wird.

6. Verfahren gemäß Anspruch 5, wobei vor dem zweiten Trennschritt die Gasphase aus dem ersten Trennschritt einem Kühlschritt unterworfen wird, um einen zweiten Strom von gasförmigen und flüssigen Produkten zu bilden.

7. Verfahren zum Durchführen einer Fischer-Tropsch-Synthesereaktion zum Herstellen von Fischer-Tropsch-Wachs, umfassend Zuführen von H₂ und CO zu einem Fischer-Tropsch-Reaktor, Durchführen des Verfahrens gemäß einem der vorstehenden Ansprüche und Abführen eines Wachs-Produktstroms aus dem Reaktor.

8. Verfahren gemäß Anspruch 7, wobei die Reaktion in einem Aufschlämmungs-Blasensäulenreaktor durchgeführt wird und wobei das H₂ und CO einer Aufschlämmung in dem Reaktor zugeführt wird, wobei die Aufschlämmung Katalysator in Suspension in einer Flüssigkeit umfasst, die die Reaktionsprodukte des H₂ und CO enthält, wobei der Katalysator wenigstens zum Teil durch die Bewegung des der Aufschlämmung zugeführten Gases in Suspension in der Aufschlämmung gehalten wird.

9. Verfahren gemäß Anspruch 8, wobei die Reaktionstemperatur in dem Bereich von 190-250 °C liegt und/oder der Reaktionsdruck in dem Bereich von 10-60 bar liegt und/oder das H₂/CO-Verhältnis des dem Fischer-Tropsch-Synthesereaktor zugeführten Gases in dem Bereich von 1,1 bis 2,2 liegt und/oder die Oberflächen-Gasgeschwindigkeit in dem Reaktor in dem Bereich von 5 bis 60 cm/s liegt.

10. Verfahren gemäß einem der Ansprüche 8 bis 9, wobei das Produkt der Fischer-Tropsch-Synthesereaktion anschließend einer Nachverarbeitung unterworfen wird, die ausgewählt sein kann aus Entwachsen, Hydroisomerisierung, Hydrocracking und Kombinationen davon.

11. Vorrichtung zum Gewinnen kondensierbarer Produkte, die in einem Auslassgasstrom eines Fischer-Tropsch-Reaktors enthalten sind, umfassend einen Fischer-Tropsch-Reaktor; eine Kondensations- und Trenneinheit; einen Gas/Flüssigkeits-Separator; eine Leitung, die zum Zuführen des Reaktorgasstroms zu der Kondensations- und Trenneinheit gestaltet ist; einen Auslass für eine kondensierte höhersiedende Fraktion aus der Kondensations- und Trenneinheit; eine Auslassleitung für eine gasförmige Fraktion aus der Kondensations- und Trenneinheit, die dafür gestaltet ist, wenigstens einen Teil der gasförmigen Fraktion dem Gas/Flüssigkeits-Separator zuzuführen; und eine Rückführleitung, die dafür gestaltet ist, verdampfbare Kohlenwasserstoffflüssigkeit aus dem Gas/Flüssigkeit-Separator der Kondensations- und Trenneinheit zuzuführen, um den Reaktorgasstrom einem direkten Wärmetausch in der Kondensations- und Trenneinheit gegen den Strom von verdampfbarer Kohlenwasserstoffflüssigkeit zu unterwerfen.

12. Vorrichtung gemäß Anspruch 11, wobei die Kondensations- und Trenneinheit eine Flüssigkeitswäschersäule ist und/oder der Reaktor ein Aufschlämmungs-Blasensäulenreaktor ist und/oder der Gas/Flüssigkeits-Separator ein Flüssigkeitsentspannungstank ist.

13. Vorrichtung gemäß einem der Ansprüche 11 bis 12, ferner umfassend einen Wärmetauscher, der indirekten Wärmetausch zwischen dem Reaktorgasstrom und einem Synthesegas-Zufuhrstrom zu dem Reaktor ermöglicht.

14. Vorrichtung gemäß einem der Ansprüche 11 bis 13, ferner umfassend einen zweiten Gas/Flüssigkeits-Separator, der dafür gestaltet ist, einen Gasstrom von dem ersten Gas/Flüssigkeits-Separator aufzunehmen, wobei der zweite Gas/Flüssigkeits-Separator ein Flüssigkeitsentspannungstank ist.

Revendications

1. Procédé pour la récupération de produits condensables contenus à l'intérieur d'un flux de gaz de sortie provenant d'un réacteur de Fischer-Tropsch, comprenant les étampes :

le transport du flux de gaz de réacteur vers une unité de condensation et de séparation ;

la soumission des gaz de F-T à un échange de chaleur direct dans l'unité de condensation et de séparation avec un flux d'hydrocarbures liquides évaporables, ce qui refroidit de cette manière les gaz de F-T ;

la condensation des constituants de point d'ébullition plus élevé présents dans les gaz de F-T ;

la séparation des constituants de point d'ébullition plus élevé condensés des constituants gazeux ; et

le soutirage d'une fraction gazeuse et d'une fraction de point d'ébullition plus élevé condensée ; dans lequel la fraction gazeuse obtenue à partir de l'étape de soutirage est soumise à une première étape de séparation dans laquelle elle est séparée en une phase gazeuse, une phase d'hydrocarbures liquides et une phase aqueuse ; et dans lequel au moins une partie de la phase d'hydrocarbures liquides provenant de la première étape de séparation constitue les hydrocarbures liquides évaporables transportés vers l'unité de séparation.

2. Procédé selon la revendication 1, dans lequel le flux de gaz de réacteur est préalablement refroidi afin de produire un mélange de constituants gazeux et liquides avant qu'il soit transporté vers l'unité de condensation et de séparation et dans lequel le refroidissement préalable peut comprendre un échange de chaleur indirect entre le flux de gaz de réacteur et un flux d'alimentation en gaz de synthèse allant vers le réacteur.

3. Procédé selon la revendication 1 ou la revendication 2, dans lequel les paramètres de fonctionnement sont réglés afin d'éviter la condensation d'eau dans l'unité de condensation et de séparation.

4. Procédé selon une quelconque revendication précédente, dans lequel avant la première étape de séparation, la fraction gazeuse est soumise à une étape de refroidissement pour former un flux de produits gazeux et liquides.

5. Procédé selon une quelconque revendication précédente, dans lequel la phase gazeuse provenant de la première étape de séparation est soumise à une seconde étape de séparation dans laquelle elle est séparée en une phase gazeuse, une phase d'hydrocarbures liquides et une phase aqueuse.

6. Procédé selon la revendication 5, dans lequel, avant la seconde étape de séparation, la phase gazeuse provenant de la première étape de séparation est soumise à une étape de refroidissement pour former un second flux de produits gazeux et liquides.

7. Procédé pour la mise en oeuvre d'une réaction de synthèse de Fischer-Tropsch pour produire des paraffines de Fischer-Tropsch qui comprend l'apport de H₂ et de CO à un réacteur de Fischer-Tropsch, la mise en oeuvre du procédé exposé dans une quelconque revendication précédente et le soutirage d'un flux de produits paraffiniques à partir du réacteur.

8. Procédé selon la revendication 7, dans lequel la réaction est effectuée dans un réacteur de type colonne à bulles à suspension épaisse et dans lequel le H₂ et le CO sont apportés à une suspension épaisse présente dans le réacteur, la suspension épaisse comprenant du catalyseur en suspension dans un liquide comprenant les produits de réaction du H₂ et du CO, le catalyseur étant maintenu en suspension dans la suspension épaisse au moins en partie par le déplacement du gaz apporté à la suspension épaisse.

9. Procédé selon la revendication 8, dans lequel la température de réaction est dans la plage de 190-250 °C et/ou la pression de réaction est dans la plage de 10-60 bar et/ou le rapport H₂/CO des gaz apportés au réacteur de synthèse de Fischer-Tropsch est dans la plage de 1,1 à 2,2 et/ou la vitesse superficielle de gaz dans le réacteur est dans la plage de 5 à 60 cm/s.

10. Procédé selon l'une quelconque des revendications 8 à 9, dans lequel le produit de la réaction de synthèse de Fischer-Tropsch est par la suite soumis à un post-traitement, qui peut être choisi entre un déparaffinage, une hydroisomérisation, un hydrocraquage et des combinaisons de ceux-ci.

11. Appareil pour la récupération de produits condensables contenus à l'intérieur d'un flux de gaz de sortie provenant d'un réacteur de Fischer-Tropsch, comprenant un réacteur de Fischer-Tropsch ; une unité de condensation et de séparation ; un séparateur gaz/liquide ; une conduite conçue pour transporter le flux de gaz de réacteur vers l'unité de condensation et de séparation ; une sortie de fraction de point d'ébullition plus élevé condensée sortant de l'unité de condensation et de séparation ; une conduite de sortie de fraction gazeuse sortant de l'unité de condensation et de séparation conçue pour transporter au moins une partie de la fraction gazeuse vers le séparateur gaz/liquide ; et une conduite de recyclage conçue pour transporter des hydrocarbures liquides évaporables du séparateur gaz/liquide vers l'unité de condensation et de séparation, ce qui soumet de cette manière le flux de gaz de réacteur à un échange de chaleur direct dans l'unité de condensation et de séparation avec le flux d'hydrocarbures liquides évaporables.

12. Appareil selon la revendication 11, dans lequel l'unité de condensation et de séparation est une colonne de lavage par un liquide et/ou le réacteur est un réacteur de type colonne à bulles à suspension épaisse et/ou le séparateur gaz/liquide est un ballon de vaporisation instantanée de liquide.

13. Appareil selon l'une quelconque des revendications 11 à 12, comprenant en outre un échangeur de chaleur facilitant l'échange de chaleur indirect entre le flux de gaz de réacteur et un flux d'alimentation en gaz de synthèse allant vers le réacteur.

14. Appareil selon l'une quelconque des revendications 11 à 13, comprenant en outre un second séparateur gaz/liquide conçu pour recevoir un flux de gaz provenant du premier séparateur gaz/liquide et dans lequel le second séparateur gaz/liquide est un ballon de vaporisation instantanée de liquide.

Drawing