KR20150104819A

KR20150104819A - Gtl production process of fpso and system thereof

Info

Publication number: KR20150104819A
Application number: KR1020140026646A
Authority: KR
Inventors: 권혁; 최정호; 김원석
Original assignee: 대우조선해양 주식회사
Priority date: 2014-03-06
Filing date: 2014-03-06
Publication date: 2015-09-16

Abstract

Disclosed are a method and a system for GTL production in FPSO. The method for gas-to-liquid (GTL) production in FPSO according to an embodiment of the present invention comprises: (a) a preprocessing step of preprocessing natural gas produced at an offshore gas field; (b) a reforming step of supplying steam and carbon dioxide to the preprocessed natural gas, and producing synthesis gas containing hydrogen and carbon monoxide by subjecting the preprocessed natural gas to a reaction in the presence of a catalyst; (c) a synthesis step of producing liquid hydrocarbon by supplying the synthesis gas to a Fisher-Tropsch reactor and subjecting the supplied synthesis gas to a reaction in the Fisher-Tropsch reactor; (d) an upgrading step of separating the liquid hydrocarbon into gas, naphtha, and synthetic crude oil and carrying out hydrofinishing by supplying hydrogen; and (e) a step of circulating generated water, generated in at least one among the steps of (b) and (c), to the step of (a), and resupplying the same.

Description

[0001] GTL PRODUCTION PROCESS OF FPSO AND SYSTEM THEREOF [0002]

The present invention relates to a GTL production process of FPSO and a system thereof, and more particularly, to a GTL production process and system thereof for FPSO capable of converting natural gas into steam in a liquid state will be.

Gas to Liquid (GTL) means a technology and a product for producing synthetic petroleum in a liquid state by processing natural gas. In recent years, high oil prices have continued, and there is growing interest in GTL technology for making liquid fuels such as diesel, which is fuel for transportation from natural gas, in accordance with the demand for environmentally friendly energy.

These GTLs are produced through desulfurization processes of natural gas, which are classified as clean fuels because they contain almost no sulfur compounds that are air pollutants.

A key process in GTL technology is Fischer-Tropsch (FT) synthesis. This technique began in 1923 when German chemists Fischer and Tropsch developed a technique for producing synthetic fuels from syngas by coal gasification.

The GTL process, which has been developed on the basis of this, proceeds in three main stages: reforming reaction of natural gas, F-T synthesis reaction of synthesis gas, and reforming reaction of product.

First, the reforming reaction step of producing a synthesis gas from natural gas is carried out through a reforming reaction of methane, which is a main component of natural gas. The reforming reaction methods include steam reforming, partial oxidation, autothermal oxidation, and steam carbon dioxide reforming.

The synthesis gas produced through the reforming reaction is subjected to an F-T synthesis reaction to produce linear paraffinic hydrocarbons. In the F-T reactor used at this time, the linear paraffinic hydrocarbons are developed in the order of a fixed bed → a circulating fluid bed → a fixed fluid bed → a slurry state.

The F-T synthesis reaction described above proceeds in the following four main reactions.

① FT synthesis (chain growth)

CO + 2H ₂ ? -CH ₂ - + H ₂ O? H (227 ° C) = -165 kJ / mol

② Methanation

CO + 3H ₂ ? CH ₄ + H ₂ O? H (227 ° C) = -215 kJ / mol

③ Water gas shift

CO + H ₂ O ↔ CO ₂ + H ₂ ΔH (227 ° C.) = -40 kJ / mol

④ Boudouard reaction

2CO ↔ C + CO ₂ ΔH (227 ° C.) = -134 kJ / mol

The high boiling point wax product produced through the F-T synthesis reaction can be purified and used as a low boiling point fuel through upgrading.

On the other hand, in the above-mentioned GTL process, fresh water is introduced as a raw material for promoting physical or chemical reaction to natural gas in a liquid or vapor state, and water is generated.

Fresh water is added to the natural gas treatment or synthetic space and discharged as wastewater, which corresponds to generated water generated in the liquid fuel synthesis process of natural gas.

Produced water produced by GTL FPSO at this time includes non-acidic components (alcohols, ketones, aldehydes) and carboxylic acids (Carboxylic acids).

If the generated water is released as it is, the marine ecosystem may be destroyed. Therefore, it must be made into clean water through the three-stage wastewater treatment and then discharged to the sea again. However, for the treatment of the generated water, a considerable process area is required on the FPSO, as in the case of land use.

For example, in the production of GTL 20,000 BPD, about 40,000 BPD of waste water is generated. Therefore, a process and method for producing a Produced Waste Water treatment system is required, which is suitable for GTL FPSO. However, since the FPSO only provides limited space, it is difficult to process the generated number in the same manner as before.

For reference, Pazflor's FPSO tank for Main Produced Water (ATM Decan. Tank (* 16m (Internal Diameter) X32m (Length))], two large tanks are installed. In the case of the GTL plant on the land, there is no restriction on the installation space, so that it can be processed based on gravity and specific gravity. In the case of land, the water treatment system takes up 1/8 of the total GTL plant.

Therefore, GTL FPSO, which is operated in the ocean compared with land, is more restricted in space, so it is necessary to apply efficient processing method and configuration of large amount of produced water generated during GTL process. When processed as such, a large storage space and additional processing steps are required.

In addition, GTL FPSO uses seawater for desalination. In the case of adopting the existing water treatment system, desalinated water is treated as generated water even after the seawater has been desalinated to a predetermined capacity required for the process.

As a result, the desalination process for desalinating the seawater must be continuously performed, so that the energy efficiency may be lowered during the GTL process, and the seawater is inefficiently consumed.

Korean Patent Application No. 10-2007-103677

One embodiment of the present invention is a GTL FPSO that can be operated in the ocean and can dramatically reduce the space required for water treatment of generated water generated during the GTL process and reduce the overall efficiency of the GTL process by reducing the amount of fresh water consumed during the GTL process We want to provide GPS production process and system of FPSO which can be high.

According to an aspect of the present invention, there is provided a method for producing natural gas, comprising the steps of: (a) pretreating natural gas produced in a marine gas field; (b) a step of supplying steam and carbon dioxide to the pretreated natural gas and reacting under a catalyst to produce a synthesis gas containing hydrogen and carbon monoxide; (c) feeding the synthesis gas to a Fischer-Tropsch reactor and reacting to produce a liquid hydrocarbon; (d) an upgrading step of separating the liquid hydrocarbon into gas, naphtha and synthetic crude oil, and supplying hydrogen to perform hydrofinishing; And (e) circulating the produced water generated in at least one of steps (b) and (c) to the step (a) and re-supplying the generated water to the step (a).

The pretreatment may include: a gas stabilization step of supplying fresh water to the natural gas to stabilize the condensed water to separate the condensed water, and to treat the product water in which the oil is mixed; A pre-reforming step of desulfurizing the natural gas after the gas stabilization step; And supplying the generated water generated in the gas stabilization step to the pre-reforming step.

And heat-exchanging the generated water with steam so that the generated water is heated.

The upgrading step comprises: 1) a separation step of separating the liquid hydrocarbon produced in the synthesis step into gas, naphtha and synthetic crude oil having 1 to 4 carbon atoms; And 2) a hydrofinishing step of supplying hydrogen to the separated naphtha to saturate the olefin.

The condensate produced in the hydrofinishing step is separated and mixed with the synthetic crude oil separated in the separation step and is fed through the hydrofinishing step to the naphtha and synthetic crude oil during storage and transportation, Gum formation and polymerization of olefins can be prevented.

A gas having a carbon number of 1 to 4 separated in the separation step may be supplied as fuel of the FPSO.

The hydrofinishing step may be carried out under relatively low temperature and pressure conditions at a temperature of 250 to 290 DEG C and a pressure of 15 to 30 bar.

Further comprising a conditioning step of conditioning the syngas produced after the reforming in the reforming step before being fed to the Fischer-Tropsch reactor in the synthesis step, wherein at least a portion of the hydrogen generated during the conditioning Step < / RTI >

The reforming step may be performed in a steam reformer (SCR).

The Fischer-Tropsch reactor in the synthesis step may comprise a Slurry Phase Reactor (SPR).

The steam carbon dioxide reformer may be a compact reformer.

In the compact reformer, carbon dioxide can participate in the synthesis reaction of the synthesis gas by the reverse reaction of the water gas shift reaction.

The unreacted synthesis gas in the slurry bed reactor may be recovered and reintroduced into the synthesis step.

The steam generated in the synthesis step and the reforming step may be supplied to the steam turbine generator provided in the FPSO to generate electricity.

According to another aspect of the present invention, there is provided a GTL production system of FPSO, comprising: a pretreatment system in which natural gas produced in an offshore gas field is pretreated including a desulfurization treatment; A steam carbon dioxide reformer (SCR) which receives the natural gas from the pre-processor and supplies steam and carbon dioxide and reacts under a catalyst to produce a synthesis gas containing hydrogen and carbon monoxide; A slurry reactor (SPR) for supplying the synthesis gas from the steam carbon dioxide reformer to produce liquid hydrocarbons; An upgrading unit for supplying hydrogen and the hydrocarbons from the slurry bed reactor to hydrofinishing to produce naphtha and synthetic crude oil; And a generated water supply unit configured to supply generated water generated from at least one of the pre-processor, the steam carbon dioxide reformer, and the slurry-phase reactor to the pre-processor, may be provided have.

Wherein the generated water re-supply unit comprises: a recirculation pipe which is arranged to combine generation water generated from at least one of the pre-processor, the steam carbon dioxide reformer, and the slurry-phase reactor to supply it to the pre-processor; And a plurality of heat exchange modules arranged to exchange heat with steam while the generated water flows in the recycle pipe.

Further comprising a conditioning unit for conditioning the syngas produced in the steam carbon dioxide reformer prior to introduction into the slurry bed reactor, wherein hydrogen produced in the conditioning unit can be supplied to the upgrading unit.

Wherein the upgrading device hydraulically supplies hydrogen to the liquid hydrocarbon to saturate the olefins contained in at least one of the naphtha and the synthetic crude oil so that the olefin in the storage and transfer of at least one of the naphtha and the synthetic crude oil gum formation and polymerization can be prevented.

The slurry phase reactor and the compound having 1 to 4 carbon atoms generated in the upgrading unit can be supplied as fuel of the combined power generation system of FPSO.

According to one embodiment of the present invention, it is possible to drastically reduce the space required for the water treatment of generated water generated in the GTL process as a GTL FPSO that can be operated in the ocean, while reducing the fresh water consumed during the GTL process, The GTL production process of the FPSO and the system thereof can be provided.

1 is a schematic diagram of a GTL production system according to an embodiment of the present invention.
2 is a block diagram of a GTL production process according to an embodiment of the present invention.
3 is a detailed schematic diagram of a preprocessor of a GTL production process according to an embodiment of the present invention.
4 is a flowchart of a GTL production process according to an embodiment of the present invention.
5 is a detailed process flow chart of Fig.
6 is a process flow chart of an up-grading step according to an embodiment of the present invention.
FIG. 7 is a schematic view of an FPSO provided on a topside of a plant to which a GTL production process according to an embodiment of the present invention is applied.

Various embodiments of the present invention will now be described by way of specific embodiments shown in the accompanying drawings. The differences between the embodiments of the present invention described below are to be understood as mutually exclusive. That is, the specific shapes, structures, and characteristics described may be embodied in other embodiments in accordance with one embodiment without departing from the spirit and scope of the present invention, It is to be understood that the arrangements may be altered, where like reference numerals refer to like or similar features throughout the several views, and length and area, thickness, and the like may be exaggerated for convenience.

Monetization using natural gas can be categorized into four major categories: 1) LNG production through general liquefaction of natural gas, 2) DME production through natural gas reforming, synthesis, separation and purification, 3) Methanol production, and 4) GTL production In this embodiment, the production process of GTL which can be used as a clean fuel for transportation instead of petroleum diesel among them will be described.

1 to 3, the GTL production process according to an embodiment of the present invention includes steps 110 and 120 of stabilizing natural gas produced in an offshore gas field and then pretreating it in a preprocessor 130, , A reforming step (200) of injecting the pretreated natural gas into the steam carbon dioxide reforming unit (140), supplying water vapor and carbon dioxide and reacting under a catalyst to produce a synthesis gas containing hydrogen and carbon monoxide, A synthesis step 250 for supplying a liquid hydrocarbon to the separator 155, separating the liquid hydrocarbon into gas, naphtha and synthetic crude oil, supplying hydrocarbons to the separator 155, and a step 460 of circulating the produced water generated in steps 110, 200, and 300 to the pretreatment step 120 and re-supplying the generated water to the preprocessing step 120.

According to this embodiment, in the steps 110 and 120 for pretreating natural gas, the step 200 for reforming natural gas, and the synthesis step 250 for producing liquid hydrocarbons, Water vapor is discharged into the product water, which is reintroduced into the pretreatment step 120 of the natural gas without the water treatment process. That is, into the preprocessor 130.

At this time, the non-acidic components (alcohols, ketones, aldehydes) and the carboxylic acids contained in the produced water are introduced into the pretreater 130 and synthesized as a fuel through the synthesis process .

As a result, the FPSO GTL production process according to the present embodiment is a GTL FPSO that can be operated in the marine environment. Therefore, it is possible to drastically reduce the space required for water production in the GTL process, It is possible to reduce the amount of fresh water introduced into the process.

The pretreatment steps 110 and 120 according to the present embodiment may include a gas stabilization step of supplying fresh water to the natural gas of the stabilizer 125 to stabilize the condensed water to separate the condensed water 155, A pre-reforming step 120 for desulfurizing the natural gas having undergone the gas stabilization step in the pre-processor 130, and a step for reforming the generated water generated in the gas stabilization step 110 to the pre-reforming step 120 (Step < RTI ID = 0.0 > 116). &Lt; / RTI >

First, in the natural gas collected from the gas field, the condensate corresponding to the useful fuel is separated and the oil-containing water is separated.

In this case, the oil is separated in the oil-mixed water, and the oil-separated water is discharged as generated water to modify the above-mentioned natural gas (200). In the synthesis step (300) And is introduced into the preprocessor 130 which is heated by the steam and then performs the pre-reforming step again.

In step 200 of modifying the natural gas, conditioning 250 of the syngas may be performed, where the product water is discharged in the conditioning step 250. The generated water discharged from the synthesis step 300 for producing the liquid hydrocarbon is further combined with the generated water discharged from the step 110 for pretreating the natural gas through the step 310 for treating the FT generated water.

Also, the FPSO GTL production process according to the present embodiment may include a step of heat-exchanging generated water and steam so that the generated water discharged from the respective steps is heated.

The generated water generally contains materials usable for fuel synthesis, and this material can be used as a pre-reforming step in the pretreatment stage to synthesize natural gas into petroleum diesel again.

Generated water may be gradually consumed by being supplied in a water vapor state and used as a raw material of petroleum diesel, and may be supplied from a fresh water storage tank by a consumption amount.

In the following, the individual process steps of the GTL process are described in more detail.

The GTL process according to the present embodiment shown in FIGS. 4 and 5 reforms the natural gas by supplying oxygen, water, and carbon dioxide to the reactor 150. The reformed gas is introduced into the reactor 150, (Synthesis), and then upgrading it to produce GTL containing naphtha and synthetic crude oil. Figure 6 shows a more detailed process flow of this embodiment.

The pretreatment step may include a step of stabilizing natural gas produced in an offshore gas field (Gas Inlet Stabilization 110), a Sulfur Removal Saturator treatment and a Pre-Reformer stage 120 have. The above-mentioned generated water is supplied to the preprocessor 130 which performs the Sulfur Removal Saturator process and the Pre-Reformer step 120.

At this time, most of the natural gas is converted into methane through the pretreatment, and the natural gas, which is mostly methane, flows through the reforming stage 200.

In this embodiment, the reforming step 200 is performed in a Steam CO ₂ Reformer (SCR) 140. The Fischer-Tropsch reactor of synthesis step 300 may also include a Slurry Phase Reactor (SPR).

As the steam carbon dioxide reformer 140 of this embodiment, for example, a compact reformer of DPT may be applied. In general, the main reaction formula in the steam carbon dioxide reformer 140 is CH ₄ + H ₂ O → 3H ₂ + CO, CH ₄ + CO ₂ → 2CO + H ₂ , and through the reformer 140, synthesis including hydrogen and carbon monoxide Gas is generated.

The synthesis gas synthesis reaction (CH ₄ + CO ₂ ? 2CO + H ₂ ) in which carbon dioxide is involved in the general steam carbon dioxide reforming unit 140 is performed by the coking reaction which is a byproduct in the reforming reaction of carbon dioxide The activity of the catalyst may be lowered and the conversion may be lowered.

In this case, when the Compact Reformer is applied, the carbon dioxide in the feed gas participates in the synthesis reaction of the synthesis gas by the reverse reaction of the water gas shift reaction of H ₂ + CO ₂ → CO + H ₂ O.

Therefore, when such a compact reformer is applied, it is possible to satisfy the following condition: R Ratio = (H ₂ -CO ₂ ) / (CO + CO ₂ ) ≈2.1, so that the caulking phenomenon can be prevented.

On the other hand, this steam CO reformer 140 as the CO ₂ tolerance is high, CO ₂ has a number of limitations dielectric (Numerous stranded gas fields) can be applied to, and carbon dioxide of natural gas is up to 30% carbon dioxide content (high CO ₂ natural gas).

The steam carbon dioxide reformer 140 such as a compact reformer is a process that does not require an oxygen separation unit (ASU) and has a low safety concern. The steam reformer 140 requires a space, such as an ATR (Autothermal Reactor) or a POR (Partial Oxidation Reactor) Weight, Height, and Electricity consumption are low. In addition, the H ₂ / CO ratio of about 2.0, which is the target for the GTL process, can be met.

The Compact Reformer is particularly suitable for offshore plants because the space required for installation is relatively small due to the relatively small ship motion effects and the small size of the heat exchanger type reactor 150 structure as compared with other reformers 140 Do.

Meanwhile, the synthesis gas generated after the reforming step 200 in the steam carbon dioxide reforming unit 140 is conditioned through the conditioning step 250 and then supplied to the Fischer-Tropsch reactor in the synthesis step 300 .

Conditioning is the process of adjusting the composition of the syngas, and at least a portion of the hydrogen that occurs during the conditioning of the syngas may be supplied for the hydrofinishing of the upgrading step 400 described above.

In this embodiment, a Slurry Phase Reactor 150 is applied to a Fischer-Tropsch reactor, for example, a Sasol SPR (Slurry Phase Reactor) may be applied.

The SPR (Slurry Phase Reactor) is suitable for offshore plants because of its small Ship Motion Effects and its relatively small total space requirement and device weight. In addition, since the catalyst is floating and circulating, it is easier to replace the catalyst than other reactors 150 such as MTFB (Multi-Tubular Fixed Bed) reactors, effective.

Only the process flow of the upgrading step 400 is shown in FIG.

7, the upgrading step 400 of the present embodiment includes: 1) a separation step 410 of separating the liquid hydrocarbons produced in the synthesis step 300 into gas, naphtha and synthetic crude oil of 1 to 4 carbon atoms ), And 2) a hydrofinishing step (420) of feeding olefin to the separated naphtha by saturating the olefin, wherein the condensate produced in the hydrofinishing step (420) is separated and separated in the separation step (430).

The synthetic crude oil (wax in FIG. 7) produced in the Fischer-Tropsch reactor 150 and separated in the separation stage 410 and the condensate produced in the hydrofinishing stage 420 are mixed (430) together with synthetic crude oil (Syscrude) And transported.

The hydrofinishing step 420 of this embodiment is carried out under relatively low temperature and pressure conditions, at a temperature of 250 to 290 ° C and a pressure of 15 to 30 bar, through such a hydrofinishing step, Gum formation and polymerization of the olefins contained in at least one of the synthetic crude oils are prevented.

The process 400 for upgrading the liquid hydrocarbon produced through the Fischer-Tropsch reactor can be designed in various processes depending on the kind of the final product to be produced.

In hydrofinishing step 420, full upgrading, including hydrocracking and hydrotreating processes, as in onshore plants, can produce a wide variety of products, which may be desirable for offshore plants, but when applied to offshore plants, The number of tanks increases and the installation space and cost are increased. Therefore, it is difficult to efficiently arrange the products. Therefore, even when the product is unloaded, it is required to pass through different unloading facilities depending on the type. Because of the complexity, placement of a hydrocracker is not an essential element.

In this embodiment, the hydrofinishing step 420 hydrogenates the olefins contained in the naphtha or synthetic crude oil to form a Simplified Upgrading Process, which prevents gum formation and polymerization during the storage and transportation of olefins .

Thus, in this embodiment, the process is designed to produce only naphtha and synthetic crude oil as GTL products and the liquid hydrocarbons are upgraded only by hydrofinishing, which can operate at relatively low pressure and temperature conditions. Therefore, the process of the upgrading step 400 is simplified, and the amount of hydrogen required for the process is small, so that the number of equipments can be reduced, which is suitable for application to a limited FPSO space.

Referring to the synthesis step 300 of FIG. 7, unreacted syngas in the slurry phase reactor 150 of the synthesis step 300 described above is recovered and reintroduced into the slurry phase reactor 150 before the synthesis stage .

In this embodiment, the gas having 1 to 4 carbon atoms separated in the separation step 410 may be supplied as the fuel of the FPSO, and the steam generated in the synthesis step 300 and the reforming step 200 may be supplied to the steam turbine It can be supplied to a generator and used for power generation.

In addition, most of the gas separated in the separation step (410) includes light olefins, which are relatively small in quantity to be transported and can be stored as fuel in FPSO.

Also, steam generated in the synthesis step 300 and the reforming step 200 according to the present embodiment is supplied to the steam turbine generator and used for power generation, so that electricity required for the FPSO is produced, thereby enhancing the energy efficiency of the GTL production.

FIG. 8 is a schematic view showing a state in which facilities (100, 200, 300, 400, 500) for each process step are provided on the topside of the FPSO and a flow of process steps are schematically shown do.

Hereinafter, a GTL production system of FPSO will be described with reference to Figs. 1 to 4 and Fig.

The GTL production system of FPSO according to an embodiment of the present invention includes a preprocessor 130 in which a natural gas produced in an offshore gas field is pre-processed including a desulfurization process, a preprocessor 130 A steam carbon dioxide reforming unit 140 (SCR) for supplying steam and carbon dioxide to the synthesis gas and reacting under a catalyst to generate a synthesis gas containing hydrogen and carbon monoxide, and a steam reforming unit 140 An upgrading unit 160 for supplying liquid hydrocarbons from the hydrogen and slurry reactor 150 and hydrofinishing them to produce naphtha and synthetic crude oil, a slurry reactor 150 for producing liquid hydrocarbons, 130, the steam carbon dioxide reforming unit 140, and the slurry-phase reactor 150 to the pretreatment unit 130 Generated which may include re-supply unit (170).

The generated water re-supply unit 170 according to the present embodiment combines generated water generated from the preprocessor 130, the steam carbon dioxide reformer 140, and the slurry reactor 150 to supply the preprocessor 130 with And a plurality of heat exchange modules 180 that are arranged to heat exchange the steam with the generated water while the generated water flows through the recirculation pipe 175.

The system according to this embodiment further comprises a conditioning unit 165 for conditioning the syngas produced in the steam carbon dioxide reformer 140 prior to introduction into the slurry bed reactor 150, The generated hydrogen may be supplied to the upgrading unit 160.

In this system, the upgrader 160 supplies hydrogen to liquid hydrocarbons to hydrofinish to saturate the olefins contained in at least one of the naphtha and the synthetic crude oil, thereby producing a sieve of olefins during storage and transport of at least one of naphtha and synthetic crude oil gum formation and polymerization can be prevented.

In the present system, preferably, the compound having 1 to 4 carbon atoms produced in the slurry bed reactor 150 and the upgrading unit 160 can be supplied as fuel for the combined power generation system of FPSO.

As described above, the GTL production process and system of the FPSO of the present invention is characterized in that the natural gas produced in the offshore gas field is pretreated, the pretreated natural gas is reformed into the steam carbon dioxide reformer 140, The GTL is produced through an up-grading step of synthesizing liquid hydrocarbons in the slurry-phase reactor 150 and then hydrofinishing the synthesized liquid hydrocarbons, as well as the pre- 130) to reduce the facilities required for water treatment of generated water, and reduce the operation rate of the desalination process after desalination at the time of the initial operation, thereby reducing unnecessary waste of sea water and increasing energy efficiency.

Thus, according to the present embodiment, a GTL production process and a production system optimized for an offshore plant environment are provided.

Further, according to this embodiment, by simplifying the synthesized liquid hydrocarbon up-grading process by hydrofinishing, it is possible to effectively place the FPSO in a limited upper space of the FPSO without requiring equipment for complicated upgrading, Maintenance becomes easy. It does not require as much hydrogen as in the case of complex upgrades of existing onshore plants, thus eliminating the need for a larger hydrogen plant and reducing the facility and operating costs of the upgrading process.

In addition, since the GTL production process and system according to the present embodiment produces only three GTLs of naphtha, synthetic crude oil, and condensate generated during hydrofinishing, the type of the tank for storing the GTL is simplified, The arrangement of the piping can be simplified. The GTL produced by the present invention is particularly suitable for implementing a compact offshore plant mounted on an FPSO, since the GTL produced by the present invention shares the same handling equipment and can be tandem-offloaded (tandem offloading).

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Deletion, addition or the like of the present invention may be variously modified and changed within the scope of the present invention.

100: preprocessing step 110: stabilization step
120: desulfurization step 130: preprocessing
140: Steam carbon dioxide reformer 150: Slurry bed reactor
160: Upgrading unit 170: Generated water supply unit
175: recirculation pipe 180: heat exchange module
200: reforming step 250: conditioning step
300: synthesis stage 350: heavy ends recovery
400: Upgrading step 410: Separation step
420: Hydrofinishing step 430: Condensate mixing
440: reforming 450: condensate mixing
500: Topside Government

Claims

(a) pre-treating the natural gas produced in a marine gas field;
(b) a step of supplying steam and carbon dioxide to the pretreated natural gas and reacting under a catalyst to produce a synthesis gas containing hydrogen and carbon monoxide;
(c) feeding the synthesis gas to a Fischer-Tropsch reactor and reacting to produce a liquid hydrocarbon;
(d) an upgrading step of separating the liquid hydrocarbon into gas, naphtha and synthetic crude oil, and supplying hydrogen to perform hydrofinishing; And
(e) circulating the produced water generated in at least one of the steps (b) and (c) to the step (a) and re-supplying the generated water to the step (a).

The method according to claim 1,
The pre-
A gas stabilization step of supplying fresh water to the natural gas to stabilize the natural gas to separate the condensate, and to treat the product water in which the oil is mixed;
A pre-reforming step of desulfurizing the natural gas after the gas stabilization step; And
And supplying the generated water generated in the gas stabilization step to the pre-reforming step.

3. The method of claim 2,
And a step of heat-exchanging the generated water with steam so that the generated water is heated.

3. The method of claim 2,
Wherein the up-
1) separating the liquid hydrocarbons produced in the synthesis step into gas, naphtha and synthetic crude oil having 1 to 4 carbon atoms; And
2) a GTL production process of FPSO comprising a hydrofinishing step of supplying hydrogen to separated naphtha to saturate olefins.

5. The method of claim 4,
The condensate produced in the hydrofinishing step is separated and mixed with the synthetic crude oil separated in the separation step,
The GTL production process of FPSO wherein gum formation and polymerization of olefins contained in at least one of the naphtha and synthetic crude oil during storage and transportation are prevented through the hydrofinishing step.

5. The method of claim 4,
Wherein the gas having a carbon number of 1 to 4 separated in the separation step is supplied as fuel of the FPSO.

5. The method of claim 4,
Wherein the hydrofinishing step is performed under relatively low temperature and pressure conditions at a temperature of 250 to 290 DEG C and a pressure of 15 to 30 bar.

The method according to claim 1,
Further comprising a conditioning step of conditioning the syngas produced after the reforming in the reforming step before feeding it to the Fischer-Tropsch reactor in the synthesis step,
Wherein at least a portion of the hydrogen generated during the conditioning is supplied to the upgrading step.

The method according to claim 1,
The reforming step is a GTL production process of FPSO conducted in a steam carbon dioxide reformer (SCR).
The Fischer-Tropsch reactor in the synthesis step is a GTL production process of FPSO comprising a Slurry Phase Reactor (SPR).

10. The method of claim 9,
The steam carbon dioxide reformer is a GTL production process of FPSO which is a compact reformer.

11. The method of claim 10,
In the compact reformer, the process of GTL production of FPSO in which carbon dioxide participates in the synthesis reaction of the synthesis gas by the reverse reaction of a water gas shift reaction.

The process of claim 9, wherein the unreacted synthesis gas in the slurry bed reactor is recovered and reintroduced into the synthesis step.

The method according to claim 1,
Wherein the steam generated in the synthesis step and the reforming step is supplied to the steam turbine generator provided in the FPSO to generate electricity.

In the GTL production system of FPSO,
A pretreatment system in which natural gas produced in the offshore gas field is pretreated including desulfurization;
A steam carbon dioxide reformer (SCR) which receives the natural gas from the pre-processor and supplies steam and carbon dioxide and reacts under a catalyst to produce a synthesis gas containing hydrogen and carbon monoxide;
A slurry reactor (SPR) for supplying the synthesis gas from the steam carbon dioxide reformer to produce liquid hydrocarbons;
An upgrading unit for supplying hydrogen and the hydrocarbons from the slurry bed reactor to hydrofinishing to produce naphtha and synthetic crude oil; And
And a generated water supply unit configured to supply generated water generated from at least one of the pre-processor, the steam carbon dioxide reformer, and the slurry-phase reactor to the pretreater.

15. The method of claim 14,
The generated water re-supply unit includes:
A re-circulation pipe arranged so that the generated water generated from at least one of the pre-processor, the steam carbon dioxide reformer, and the slurry-phase reactor is combined and supplied to the pre-processor; And
And a plurality of heat exchange modules arranged to heat exchange steam with the generated water while flowing through the recirculation pipe.

15. The method of claim 14,
Further comprising a conditioning unit for conditioning the syngas produced in the steam carbon dioxide reformer prior to introduction into the slurry bed reactor,
Wherein the hydrogen generated in the conditioning unit is supplied to the upgrading unit.

15. The method of claim 14,
Wherein the upgrading device hydraulically supplies hydrogen to the liquid hydrocarbon to saturate the olefins contained in at least one of the naphtha and the synthetic crude oil so that the olefin in the storage and transfer of at least one of the naphtha and the synthetic crude oil Gum production system of FPSO in which gum formation and polymerization are prevented.

15. The method of claim 14,
Wherein the slurry phase reactor and the compound having 1 to 4 carbon atoms generated in the upgrading unit are supplied as fuel for the combined power generation system of the FPSO.