AU2007232991A1

AU2007232991A1 - Liquid fuel synthesizing system

Info

Publication number: AU2007232991A1
Application number: AU2007232991A
Authority: AU
Inventors: Kenichiro Fujimoto; Yasuhiro Onishi; Osamu Wakamura
Original assignee: Nippon Steel Engineering Co Ltd
Current assignee: Nippon Steel Engineering Co Ltd
Priority date: 2006-03-30
Filing date: 2007-03-29
Publication date: 2007-10-11
Also published as: WO2007114250A1; JPWO2007114250A1; CN101432395A; RU2008140161A; ZA200808235B

Description

DECLARATION I, Toru ISHIKAWA of c/o SHIGA INTERNATIONAL PATENT OFFICE, GranTokyo South Tower, 1-9-2 Marunouchi, Chiyoda-ku, Tokyo, Japan, understand both English and Japanese, am the translator of the English document attached, and do hereby declare and state that the attached English document contains an accurate translation of PCT International Application PCT/JP2007/056862 as filed on March 29, 2007, and that all statements made herein are true to the best of my knowledge. Declared in Tokyo, Japan This 10th day of September, 2008. Toru ISHIKAWA OSP-27770AU 1 SPECIFICATION LIQUID FUEL SYNTHESIZING SYSTEM 5 TECHNICAL FIELD [0001] The present invention relates to a liquid fuel synthesizing system. Priority is claimed on Japanese Patent Application No. 2006-95932, filed March 30, 2006, the content of which is incorporated herein by reference. 10 BACKGROUND ART OF THE INVENTION [0002] As one of the methods for synthesizing liquid fuel from natural gas, a GTL (Gas-To-Liquid: liquid fuel synthesis) technique of reforming natural gas to produce synthesis gas including carbon monoxide gas (CO) and hydrogen gas (H 2 ) as main components, synthesizing liquid hydrocarbons using this synthesis gas as a source gas by 15 the Fischer-Tropsch synthesis reaction (hereinafter referred to as "FT synthesis reaction"), and further hydrogenating and hydrocracking the liquid hydrocarbons to manufacture liquid fuel products, such as naphtha (rough gasoline), kerosene, gas oil, and wax, has recently been developed. [0003] A liquid fuel synthesizing system using the GTL technique includes a reformer 20 that reforms natural gas to produce carbon monoxide gas and hydrogen gas, a reactor that produces liquid fuel from a synthesis gas produced by the reformer with the synthesis reaction, etc. Also, in order to improve the reaction rate of the FT synthesis reaction in the reactor, it is necessary to suitably set the pressure of the synthesis gas introduced into the reactor, and to suitably adjust the reaction pressure in the reactor. 25 OSP-27770AU 2 DISCLOSURE OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION [0004] However, a CO 2 removal unit, pipelines, valves, etc. may be provided between the reformer and the reactor. Accordingly, in the conventional liquid fuel synthesizing 5 system, the pressure of the synthesis gas delivered from the reformer reduces by pressure losses caused by the apparatus, pipelines, etc. at the time of introduction of the synthesis gas into the reactor. As a result, since the reaction pressure in the reactor does not reach a suitable pressure, the reaction rate of the synthesis reaction is lowered. [0005] Thus, the present invention has been made in view of the above problem, and 10 aims at providing a liquid fuel synthesizing system capable of securing a stable reaction pressure required for a synthesis reaction in a reactor, and improving the reaction rate of the synthesis reaction. MEANS FOR SOLVING THE PROBLEMS 15 [0006] A liquid fuel synthesizing system of the present invention includes: a reformer that reforms a hydrocarbon raw material to produce synthesis gas including carbon monoxide gas and hydrogen gas as main components; a reactor that synthesizes liquid hydrocarbons from the carbon monoxide gas and hydrogen gas included in the synthesis gas; a supply path of the synthesis gas from the reformer to the reactor; and a first 20 compression apparatus that is provided on the supply path to compress the synthesis gas produced by the reformer to at least more than a predetermined reaction pressure in the reactor. [0007] By such a configuration, the first compression apparatus can compress synthesis gas to more than the pressure of the synthesis gas delivered from the synthesis gas 25 production unit composed of a reformer, etc., thereby introducing synthesis gas having a OSP-27770AU 3 higher pressure than the pressure within a reactor into the reactor. As a result, a stable reaction pressure required for the synthesis reaction in the reactor can be secured, and the reaction rate of the synthesis reaction can be improved. [0008] The liquid fuel synthesizing system may further include a waste heat boiler that 5 recovers the heat of the synthesis gas produced by the reformer to generate steam, and the first compressor may be driven using the steam generated in the waste heat boiler as a power source. By such a configuration, the waste heat boiler recovers the thermal energy of the synthesis gas produced by the reformer, to generate steam. The steam generated from the waste heat boiler serves as a power source of a steam turbine 10 connected to the first compression apparatus, and the first compression apparatus is driven by this steam turbine. [0009] The liquid fuel synthesizing system may further include a recycle path that returns unreacted synthesis gas discharged from the reactor to an introducing port of the reactor, and a second compressor that is provided on the recycle path to compress the 15 unreacted synthesis gas to at least more than a predetermined reaction pressure in the reactor. By such a configuration, the second compression apparatus can compress synthesis gas to more than the pressure of the unreacted synthesis gas delivered from the reactor, thereby introducing a higher pressure of the synthesis gas again into the reactor. [0010] The liquid fuel synthesizing system may further include a waste heat boiler that 20 recovers the heat of the synthesis gas produced by the reformer to generate steam, and the second compressor may be driven using the steam generated in the waste heat boiler as a power source. By such a configuration, the waste heat boiler recovers the thermal energy of the synthesis gas produced by the reformer, to generate steam. The steam generated from the waste heat boiler serves as a power source of a steam turbine 25 connected to the second compression apparatus, and the second compression apparatus is OSP-27770AU 4 driven by this steam turbine. [0011] The liquid fuel synthesizing system may further include a waste heat boiler that recovers the heat of the synthesis gas produced by the reformer to generate steam, and a generator that is driven using the steam generated in the waste heat boiler as a power 5 source and that supplies electric power to each apparatus in the liquid fuel synthesizing system. By such a configuration, the waste heat boiler recovers the thermal energy of the synthesis gas produced by the reformer, to generate steam. The steam generated from the waste heat boiler serves as a power source of a steam turbine connected to the generator, and the generator is driven by this steam turbine to generate electricity. 10 [0012] The steam generated in the above waste heat boiler is directly supplied from the waste heat boiler to the generator without pressure loss thereof. By such a configuration, the energy held by the steam generated from the waste heat boiler can be utilized effectively. 15 ADVANTAGEOUS EFFECTS OF THE INVENTION [0013] As described above, according to the present invention, a stable reaction pressure required for the synthesis reaction in the reactor can be secured, and the reaction rate of the synthesis reaction can be improved. 20 BRIEF DESCRIPTION OF THE DRAWINGS [0014] [FIG 1] FIG. 1 is a schematic diagram showing the overall configuration of a liquid fuel synthesizing system according to an embodiment of the present invention. [FIG. 2] FIG. 2 is a block diagram showing an exemplary configuration of a high-pressure steam system in the liquid fuel synthesizing system according to the 25 embodiment of the present invention.

OSP-27770AU 5 [FIG. 3] FIG. 3 is a schematic diagram showing the configuration of a compressor in the liquid fuel synthesizing system according to the embodiment of the present invention. 5 DESCRIPTION OF THE REFERENCE SYMBOLS [0015] 1: LIQUID FUEL SYNTHESIZING SYSTEM 3: SYNTHESIS GAS PRODUCTION UNIT 5: FT SYNTHESIS UNIT 7: UPGRADING UNIT 10 10: DESULFURIZING REACTOR 12: REFORMER 14: WASTE HEAT BOILER 16, 18, 34, 38, 56, 58 and 60: GAS-LIQUID SEPARATORS 20: CO 2 REMOVAL UNIT 15 22: ABSORPTION COLUMN 24: REGENERATION COLUMN 26: HYDROGEN SEPARATING APPARATUS 30: BUBBLE COLUMN REACTOR 32: HEAT TRANSFER PIPE 20 36: SEPARATOR 40: FIRST RECTIFYING COLUMN 50: WAX COMPONENT HYDROCRACKING REACTOR 52: KEROSENE AND GAS OIL FRACTION HYDROTREATING REACTOR 25 54: NAPHTHA FRACTION HYDROTREATING REACTOR OSP-27770AU 6 70: SECOND RECTIFYING COLUMN 72: NAPHTHA STABILIZER 110: FIRST COMPRESSION APPARATUS 112: STEAM TURBINE 5 114: COMPRESSOR 116: MOTOR PART 120: SECOND COMPRESSION APPARATUS 132: STEAM TURBINE 134: GENERATOR 10 136: POWER STORAGE FACILITY 138: TRANSFORMER SUBSTATION 140, 142, 144, 146 and 150: PIPELINE DESCRIPTION OF THE PREFERRED EMBODIMENTS 15 [0016] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, in the present specification and drawings, duplicate description is omitted by giving the same reference numerals to constituent parts having substantially the same functional configurations. [0017] First, with reference to FIG. 1, the overall configuration and operation of a liquid 20 fuel synthesizing system 1 which carries out a GTL (Gas-To-Liquid) process according to an embodiment of the present invention will be described. FIG. 1 is a schematic diagram showing the overall configuration of the liquid fuel synthesizing system 1 according to the present embodiment. [0018] As shown in FIG. 1, the liquid fuel synthesizing system 1 according to the 25 present embodiment is a plant facility which carries out the GTL process which converts OSP-27770AU 7 a hydrocarbon raw material, such as natural gas, into liquid fuels. This liquid fuel synthesizing system 1 includes a synthesis gas production unit 3, an FT synthesis unit 5, and an upgrading unit 7. The synthesis gas production unit 3 reforms natural gas, which is a hydrocarbon raw material, to produce synthesis gas including carbon monoxide gas 5 and hydrogen gas. The FT synthesis unit 5 produces liquid hydrocarbons from the above synthesis gas by the Fischer-Tropsch synthesis reaction (hereinafter referred to as "FT synthesis reaction"). The upgrading unit 7 hydrogenates and hydrocracks the liquid hydrocarbons produced by the FT synthesis reaction to manufacture liquid fuel products (naphtha, kerosene, gas oil, etc.). Hereinafter, constituent parts of each of these units 10 will be described. [0019] First, the synthesis gas production unit 3 will be described. The synthesis gas production unit 3 mainly includes, for example, a desulfurizing reactor 10, a reformer 12, a waste heat boiler 14, gas-liquid separators 16 and 18, a CO 2 removal unit 20, and a hydrogen separating apparatus 26. The desulfurizing reactor 10 is composed of a 15 hydrogenation desulfurizer, etc., and removes a sulfur component from natural gas as a raw material. The reformer 12 reforms the natural gas supplied from the desulfurizing reactor 10, to produce synthesis gas including carbon monoxide gas (CO) and hydrogen gas (H 2 ) as main components. The waste heat boiler 14 recovers heat duty of the synthesis gas produced by the reformer 12, to manufacture high-pressure steam. The 20 gas-liquid separator 16 separates the water heated by heat exchange with the synthesis gas in the waste heat boiler 14 into gas (high-pressure steam) and liquid. The gas-liquid separator 18 removes condensate components from the synthesis gas cooled down in the waste heat boiler 14, and supplies a gas component to the CO 2 removal unit 20. The

CO

2 removal unit 20 has an absorption column 22 which removes carbon dioxide gas 25 from the synthesis gas supplied from the gas-liquid separator 18 by absorption, and a OSP-27770AU 8 regeneration column 24 which diffuses and regenerates the carbon dioxide gas from the absorbent including the carbon dioxide gas. The hydrogen separating apparatus 26 separates a part of the hydrogen gas included in the synthesis gas from the synthesis gas, the carbon dioxide gas of which has been separated by the CO 2 removal unit 20. It is to 5 be noted herein that the above CO 2 removal unit 20 may not be provided depending on circumstances. [0020] Among them, the reformer 12 reforms natural gas by using carbon dioxide and steam to produce high-temperature synthesis gas including carbon monoxide gas and hydrogen gas as main components, by a steam and carbon-dioxide-gas reforming method 10 expressed by the following chemical reaction formulas (1) and (2). In addition, the reforming method in this reformer 12 is not limited to the example of the above steam and carbon-dioxide-gas reforming method. For example, a steam reforming method, a partial oxidation method (POX) using oxygen, an autothermal reforming method (ATR) that is a combination of the partial oxidation method and the steam reforming method, a 15 carbon-dioxide-gas reforming method, and the like can also be utilized. [0021] CH 4 + H 2 0-- CO + 3H 2 "' (1)

CH

4 + CO2 -> 2CO + 2H 2 ... (2) [0022] Further, the hydrogen separating apparatus 26 is provided on a line branched from a main pipe which connects the CO 2 removal unit 20 or gas-liquid separator 18 with 20 the bubble column reactor 30. This hydrogen separating apparatus 26 can be composed of, for example, a hydrogen PSA (Pressure Swing Adsorption) device which performs adsorption and desorption of hydrogen by using a pressure difference. This hydrogen PSA apparatus has adsorbents (zeolitic adsorbent, activated carbon, alumina, silica gel, etc.) within a plurality of adsorption columns (not shown) which are arranged in parallel. 25 By sequentially repeating processes including pressurizing, adsorption, desorption OSP-27770AU 9 (pressure reduction), and purging of hydrogen in each of the adsorption columns, high-purity (for example, about 99.999%) hydrogen gas separated from the synthesis gas can be continuously supplied to a reactor. [0023] In addition, the hydrogen gas separating method in the hydrogen separating 5 apparatus 26 is not limited to the example of the pressure swing adsorption method as in the above hydrogen PSA device. For example, there may be a hydrogen storing alloy adsorption method, a membrane separation method, or a combination thereof. [0024] Next, the FT synthesis unit 5 will be described. The FT synthesis unit 5 mainly includes, for example, the bubble column reactor 30, a gas-liquid separator 34, a 10 separator 36, a gas-liquid separator 38, and a first rectifying column 40. The bubble column reactor 30 carries out an FT synthesis reaction of the synthesis gas produced in the above synthesis gas production unit 3, i.e., carbon monoxide gas and hydrogen gas, to produce liquid hydrocarbons. The gas-liquid separator 34 separates the water circulated and heated through a heat transfer pipe 32 disposed in the bubble column reactor 30 into 15 steam (medium-pressure steam) and liquid. The separator 36 is connected to a central part of the bubble column reactor 30, and separates a catalyst and a liquid hydrocarbon product. The gas-liquid separator 38 is connected to an upper part of the bubble column reactor 30, and cools down unreacted synthesis gas and gaseous hydrocarbon product. The first rectifying column 40 distills the liquid hydrocarbons supplied via the separator 20 36 and the gas-liquid separator 38 from the bubble column reactor 30, and separates and refines the liquid hydrocarbons into individual product fractions according to boiling points. [0025] Among them, the bubble column reactor 30, which is an example of a reactor which converts synthesis gas to liquid hydrocarbons, functions as a reactor which 25 produces liquid hydrocarbons from synthesis gas by the FT synthesis reaction. This OSP-27770AU 10 bubble column reactor 30 is composed of, for example, a slurry bubble column reactor in which slurry consisting of a catalyst and medium oil is reserved inside a column. This bubble column reactor 30 produces liquid hydrocarbons from synthesis gas by the FT synthesis reaction. In detail, in this bubble column reactor 30, the synthesis gas as a 5 source gas is supplied as bubbles from a dispersing plate at the bottom of the bubble column reactor 30, and passes through the slurry consisting of a catalyst and medium oil, and in a suspended state, hydrogen gas and carbon monoxide gas cause a synthesis reaction with catalyst, as shown in the following chemical reaction formula (3). [00026 2nH2 + nCO -+ (-CH 2 -)n + nH 2 0 " (3) 10 [0027] Since this FT synthesis reaction is an exothermic reaction, the bubble column reactor 30, which is a heat exchanger-type reactor within which the heat transfer pipe 32 is disposed, is adapted such that, for example, water (BFW: Boiler Feed Water) is supplied as a refrigerant so that reaction heat of the above FT synthesis reaction can be recovered as medium-pressure steam by heat exchange between slurry and water. 15 [0028] Finally, the upgrading unit 7 will be described. The upgrading unit 7 includes, for example, a WAX component hydrocracking reactor 50, a kerosene and gas oil fraction hydrotreating reactor 52, a naphtha fraction hydrotreating reactor 54, gas-liquid separators 56, 58 and 60, a second rectifying column 70, and a naphtha stabilizer 72. The WAX component hydrocracking reactor 50 is connected to a lower part of the first 20 rectifying column 40. The kerosene and gas oil fraction hydrotreating reactor 52 is connected to a central part of the first rectifying column 40. The naphtha fraction hydrotreating reactor 54 is connected to an upper part of the first rectifying column 40. The gas-liquid separators 56, 58 and 60 are provided so as to correspond to the hydrogenation reactors 50, 52 and 54, respectively. The second rectifying column 70 25 separates and refines the liquid hydrocarbons supplied from the gas-liquid separators 56 OSP-27770AU 11 and 58 according to boiling points. The naphtha stabilizer 72 rectifies liquid hydrocarbons of a naphtha fraction supplied from the gas-liquid separator 60 and the second rectifying column 70. Then, the naphtha stabilizer 72 discharges components lighter than butane towards flare gas (emission gas), and to separate and recover 5 components having a carbon number of five or more as a naphtha product. [0029] Next, a process (GTL process) of synthesizing liquid fuel from natural gas by the liquid fuel synthesizing system 1 configured as above will be described. [0030] Natural gas (whose main component is CH 4 ) as a hydrocarbon raw material is supplied to the liquid fuel synthesizing system 1 from an external natural gas supply 10 source (not shown), such as a natural gas field or a natural gas plant. The above synthesis gas production unit 3 reforms this natural gas to manufacture synthesis gas (mixed gas including carbon monoxide gas and hydrogen gas as main components). [0031] Specifically, first, the above natural gas is supplied to the desulfurizing reactor 10 along with the hydrogen gas separated by the hydrogen separating apparatus 26. The 15 desulfurizing reactor 10 hydrogenates and desulfurizes a sulfur component included in the natural gas using the hydrogen gas, with a ZnO catalyst. By desulfurizing natural gas in advance in this way, it is possible to prevent from decreasing activity of a catalyst used in the reformer 12, the bubble column reactor 30, etc. because of sulfur. [0032] The natural gas (may also contain carbon dioxide) desulfurized in this way is 20 supplied to the reformer 12 after the carbon dioxide (CO 2 ) gas supplied from a carbon-dioxide supply source (not shown) and the steam generated in the waste heat boiler 14 are mixed to the desulfurized natural gas. The reformer 12 reforms natural gas by using carbon dioxide and steam to produce high-temperature synthesis gas including carbon monoxide gas and hydrogen gas as main components, by the above steam and 25 carbon-dioxide-gas reforming method. At this time, the reformer 12 is supplied with, OSP-27770AU 12 for example, fuel gas for a burner disposed in the reformer 12 and air, and reaction heat required for the above steam and carbon-dioxide-gas reforming reaction, which is an endothermic reaction, is provided by the heat of combustion of the fuel gas in the burner. [0033] The high-temperature synthesis gas (for example, 900 0 C, 2.0 MPaG) produced 5 in the reformer 12 in this way is supplied to the waste heat boiler 14, and is cooled down by the heat exchange with the water which circulates through the waste heat boiler 14 (for example, 400 0 C), thereby exhausting and recovering heat. At this time, the water heated by the synthesis gas in the waste heat boiler 14 is supplied to the gas-liquid separator 16. From this gas-liquid separator 16, a gas component is supplied to the 10 reformer 12 or other external devices as high-pressure steam (for example, 3.4 to 10.0 MPaG), and water as a liquid component is returned to the waste heat boiler 14. [0034] Meanwhile, the synthesis gas cooled down in the waste heat boiler 14 is supplied to the absorption column 22 of the CO 2 removal unit 20, or the bubble column reactor 30, after condensate components are separated and removed from the synthesis 15 gas in the gas-liquid separator 18. The absorption column 22 absorbs carbon dioxide gas included in the synthesis gas into the circulated absorbent, to remove the carbon dioxide gas from the synthesis gas. The absorbent including the carbon dioxide gas within this absorption column 22 is introduced into the regeneration column 24, the absorbent including the carbon dioxide gas is heated and subjected to stripping treatment 20 with, for example, steam, and the resulting diffused carbon dioxide gas is delivered to the reformer 12 from the regeneration column 24, and is reused for the above reforming reaction. [0035] The synthesis gas produced in the synthesis gas production unit 3 in this way is supplied to the bubble column reactor 30 of the above FT synthesis unit 5. At this time, 25 the composition ratio of the synthesis gas supplied to the bubble column reactor 30 is OSP-27770AU 13 adjusted to a composition ratio (for example, H 2 :CO = 2:1 (molar ratio)) suitable for the FT synthesis reaction. In addition, the pressure of the synthesis gas supplied to the bubble column reactor 30 is raised to be suitable (for example, 3.6 MPaG) for the FT synthesis reaction by a first compression apparatus 110 provided on a pipe 150 of a 5 synthesis gas supply path which connects the CO 2 removal unit 20 with the bubble column reactor 30, and details thereof will be described below. [0036] Further, a part of the synthesis gas, the carbon dioxide gas of which has been separated by the above CO 2 removal unit 20, is also supplied to the hydrogen separating apparatus 26. The hydrogen separating apparatus 26 separates the hydrogen gas 10 included in the synthesis gas, by the adsorption and desorption (hydrogen PSA) utilizing a pressure difference as described above. This separated hydrogen is continuously supplied from a gas holder (not shown), etc. via a compressor (not shown) to various hydrogen-utilizing reaction devices (for example, the desulfurizing reactor 10, the WAX component hydrocracking reactor 50, the kerosene and gas oil fraction hydrotreating 15 reactor 52, the naphtha fraction hydrotreating reactor 54, etc.) which perform predetermined reactions utilizing hydrogen within the liquid fuel synthesizing system 1. [0037] Next, the above FT synthesis unit 5 produces liquid hydrocarbons by the FT synthesis reaction from the synthesis gas produced by the above synthesis gas production unit 3. 20 [0038] Specifically, the synthesis gas produced by the above synthesis gas production unit 3 flows into the bubble column reactor 30 from the bottom of the reactor 30, and flows up through the catalyst slurry reserved in the bubble column reactor 30. At this time, within the bubble column reactor 30, the carbon monoxide and hydrogen gas which are included in the synthesis gas react with each other by the FT synthesis reaction, 25 thereby producing hydrocarbons. Moreover, by circulating water through the heat OSP-27770AU 14 transfer pipe 32 in the bubble column reactor 30 at the time of this synthesis reaction, the heat of the FT synthesis reaction is removed, and the water heated by this heat exchange is vaporized into steam. As for this water vapor, the water separated in the gas-liquid separator 34 is returned to the heat transfer pipe 32, and the vapor is supplied to an 5 external device as medium-pressure steam (for example, 1.0 to 2.5 MPaG). [0039] The liquid hydrocarbons synthesized in the bubble column reactor 30 in this way are removed from the central part of the bubble column reactor 30, and are introduced into the separator 36. The separator 36 separates the introduced liquid hydrocarbons into a catalyst (solid component) in the extracted slurry, and a liquid component 10 including a liquid hydrocarbon product. A part of the separated catalyst is supplied to the bubble column reactor 30, and a liquid component thereof is supplied to the first rectifying column 40. From the top of the bubble column reactor 30, unreacted synthesis gas, and a gas component of the synthesized hydrocarbons are introduced into the gas-liquid separator 38. The gas-liquid separator 38 cools down these gases, and 15 then separates some condensed liquid hydrocarbons to introduce them into the first rectifying column 40. Meanwhile, as the gas component separated in the gas-liquid separator 38, unreacted synthesis gases (CO and H 2 ) are put into the bottom of the bubble column reactor 30, and reused for the FT synthesis reaction. Further, the emission gas (flare gas) other than target products, which contains hydrocarbon gas having a low 20 carbon number (C 4 or less) as a main component, is introduced into an external combustion facility (not shown) to be combusted, and is then discharged to the atmosphere. [0040] Meanwhile, as for a gaseous part separated in the gas-liquid separator 38, hydrocarbon gas having a low carbon number (C 4 or less), which are other than target 25 products and unreacted synthesis gas (CO and H 2 ), are withdrawn by a required amount OSP-27770AU 15 by a second compression apparatus 120 provided on pipelines 142 and 146 as a recycle path, and are introduced again into the bottom of the bubble column reactor 30 via pipelines 140,142, and 146. The unreacted synthesis gas (CO and H 2 ) of these gases is reused for the FT synthesis reaction. Further, a part of the gas separated in the 5 gas-liquid separator 38 is introduced into and combusted in an external combustion facility (not shown) via pipelines 140 and 144, as emission gas (flare gas) containing the hydrocarbon gas and unreacted synthesis gas of not more than C 4 as components, and is then discharged to the atmosphere. [0041] Next, the first rectifying column 40 heats the liquid hydrocarbons (whose carbon 10 numbers are various) supplied via the separator 36 and the gas-liquid separator 38 from the bubble column reactor 30 as described above, to fractionally distill the liquid hydrogen using a difference in boiling point. Thereby, the first rectifying column 40 separates and refines the liquid hydrogen into a naphtha fraction (whose boiling point is less than about 315 0 C), a kerosene and gas oil fraction (whose boiling point is about 315 15 to 800 0 C), and a WAX component (whose boiling point is greater than about 800 0 C). The liquid hydrocarbons (mainly C 2 1 or more) as the WAX component extracted from the bottom of the first rectifying column 40 are transferred to the WAX component hydrocracking reactor 50, the liquid hydrocarbons (mainly C 1 to C 20 ) as the kerosene and gas oil fraction removed from the central part of the first rectifying column 40 are 20 transferred to the kerosene and gas oil fraction hydrotreating reactor 52, and the liquid hydrocarbons (mainly C 5 to CO 10 ) as the naphtha fraction extracted from the upper part of the first rectifying column 40 are transferred to the naphtha fraction hydrotreating reactor 54. [0042] The WAX component hydrocracking reactor 50 hydrocracks the liquid 25 hydrocarbons as the WAX component with a large carbon number (approximately C 2 1 or OSP-27770AU 16 more), which has been supplied from the lower part of the first rectifying column 40, by using the hydrogen gas supplied from the above hydrogen separating apparatus 26, to reduce the carbon number to less than C 20 . In this hydrocracking reaction, hydrocarbons with a large carbon number and with low molecular weight are generated 5 by cleaving C-C bonds of hydrocarbons with a large carbon number, using a catalyst and heat. A product including the liquid hydrocarbons hydrocracked by this WAX component hydrocracking reactor 50 is separated into gas and liquid in the gas-liquid separator 56, the liquid hydrocarbons of which are transferred to the second rectifying column 70, and the gas component (including hydrogen gas) of which is transferred to 10 the kerosene and gas oil fraction hydrotreating reactor 52 and the naphtha fraction hydrotreating reactor 54. [0043] The kerosene and gas oil fraction hydrotreating reactor 52 hydrotreats liquid hydrocarbons (approximately CI to C 20 ) as the kerosene and gas oil fractions having an approximately middle carbon number, which have been supplied from the central part of 15 the first rectifying column 40, by using the hydrogen gas supplied via the WAX component hydrocracking reactor 50 from the hydrogen separating apparatus 26. This hydrotreating reaction is a reaction which adds hydrogen to unsaturated bonds of the above liquid hydrocarbons, to saturate the liquid hydrocarbons and to generate straight-chain saturated hydrocarbons. As a result, a product including the hydrotreated 20 liquid hydrocarbons is separated into gas and liquid in the gas-liquid separator 58, the liquid hydrocarbons of which are transferred to the second rectifying column 70, and the gas component (including hydrogen gas) of which is reused for the above hydrogenation reaction. [0044] The naphtha fraction hydrotreating reactor 54 hydrotreats liquid hydrocarbons 25 (approximately Co 10 or less) as the naphtha fraction having a low carbon number, which OSP-27770AU 17 have been supplied from the upper part of the first rectifying column 40, by using the hydrogen gas supplied via the WAX component hydrocracking reactor 50 from the hydrogen separating apparatus 26. As a result, a product including the hydrotreated liquid hydrocarbons is separated into gas and liquid in the gas-liquid separator 60, the 5 liquid hydrocarbons of which are transferred to the naphtha stabilizer 72, and the gas component (including hydrogen gas) of which is reused for the above hydrogenation reaction. [0045] Next, the second rectifying column 70 distills the liquid hydrocarbons supplied from the WAX component hydrocracking reactor 50 and the kerosene and gas oil fraction 10 hydrotreating reactor 52 as described above. Thereby, the second rectifying column 70 separates and refines the liquid hydrogen into a naphtha fraction (whose boiling point is less than about 315 0 C) with a carbon number of 10 or less, kerosene (whose boiling point is about 315 to 450 0 C), and gas oil (whose boiling point is about 450 to 800 0 C). The gas oil is extracted from a lower part of the second rectifying column 70, and the 15 kerosene is extracted from a central part thereof. Meanwhile, a hydrocarbon gas with a carbon number of 10 or more is extracted from the top of the second rectifying column 70, and is supplied to the naphtha stabilizer 72. [0046] Moreover, the naphtha stabilizer 72 distills the hydrocarbons with a carbon number of 10 or less, which have been supplied from the above naphtha fraction 20 hydrotreating reactor 54 and second rectifying column 70. Thereby, the naphtha stabilizer 72 separates and refines naphtha (C 5 to C 0 lo) as a product. Accordingly, high-purity naphtha is extracted from a lower part of the naphtha stabilizer 72. Meanwhile, the emission gas (flare gas) other than products, which contains as a main component hydrocarbons with a carbon number lower than or equal to a predetermined 25 number or less (lower than or equal to C 4 ) is discharged from the top of the naphtha OSP-27770AU 18 stabilizer 72. Further, the emission gas is introduced into an external combustion facility (not shown), is combusted therein, and is then discharged to the atmosphere. [0047] The process (GTL process) of the liquid fuel synthesizing system 1 has been described hitherto. By the GTL process, natural gas can be easily and economically 5 converted into clean liquid fuels, such as high-purity naphtha (C 5 to Clo: rough gasoline), kerosene (Cll to C15is: kerosene), and gas oil (C 1 6 to C 20 : gas oil). Moreover, in the present embodiment, the above steam and carbon-dioxide-gas reforming method is adopted in the reformer 12. Thus, there are advantages in that carbon dioxide contained in natural gas to be used as a raw material can be effectively utilized, the composition 10 ratio (for example, H 2 :CO = 2:1 (molar ratio)) of a synthesis gas suitable for the above FT synthesis reaction can be efficiently produced in one reaction of the reformer 12, and a hydrogen concentration adjustor, etc. is unnecessary. [0048] Meanwhile, a conventional liquid fuel synthesizing system has problems in that, since neither the first compression apparatus 110 nor the second compression apparatus 15 120 are installed, the pressure of the synthesis gas delivered from the reformer and the pressure of the synthesis gas delivered from the top of the bubble column reactor decrease due to pressure losses of apparatuses, pipelines, etc. until the synthesis gas is introduced into the bubble column reactor. Further, there is a problem in that, when the synthesis gas of which the pressure has dropped is introduced into the bubble column 20 reactor, the reaction rate of synthesis reaction in the bubble column reactor degrades. [0049] Moreover, in the liquid fuel synthesizing system, emission gas close to about 1000 0 C is emitted in a reforming process of a reformer which reforms natural gas to produce synthesis gas including carbon monoxide gas and hydrogen gas. Therefore, a waste heat boiler recovers waste heat to generate a large amount of high-pressure steam. 25 Conventionally, this high-pressure steam is often utilized as a heat source for heating of OSP-27770AU 19 tower or bath equipment in a pressure-reduced state. [0050] Moreover, since the liquid fuel synthesizing system has the processing operation which heats low-temperature liquid to supply the liquid to a rectifying column at an elevated temperature or cools down high-temperature liquid to low temperature and this 5 temperature difference is large, there is a problem in that heating steam and cooling water are required in large quantities, and the energy efficiency of the whole liquid fuel synthesizing system is poor. [0051] Thus, in the liquid fuel synthesizing system 1 according to the embodiment of the present invention, a configuration in which the steam generated in the waste heat 10 boiler 14 is utilized for the first compression apparatus 110, the second compression apparatus 120, and a generator 134 will be described with reference to FIGS. 1 and FIG. 2. FIG 2 is a schematic diagram showing an exemplary configuration of a high-pressure steam system of the liquid fuel synthesizing system 1 according to the present embodiment. 15 [0052] The liquid fuel synthesizing system 1 according to the present embodiment, as shown in FIG 1 and FIG. 2, includes the first compression apparatus 110 which compresses the synthesis gas synthesized in the reformer 12, the second compression apparatus 120 which compresses the unreacted synthesis gas recycled from the bubble column reactor 30, and the generator 134 that is driven by a steam turbine 132 which 20 uses the steam generated in the waste heat boiler 14 as a power source. [0053] The first compression apparatus 110 is arranged on the downstream side of the

CO

2 removal unit 20 in the pipeline 150 as a supply path through which synthesis gas flows. Also, the first compression apparatus 110 is arranged on the upstream side of a synthesis gas introducing port of the bubble column reactor 30 so that the synthesis gas 25 compressed in the first compression apparatus 110 may be introduced into the bubble OSP-27770AU 20 column reactor 30. Here, the pipeline 150, which is a supply path for synthesis gas, is configured such that it is connected to the bubble column reactor 30 via the gas-liquid separator 18 and the CO 2 removal unit 20 from the waste heat boilers 14. [0054] The second compression apparatus 120 is arranged in the pipelines 142 and 146 5 as recycle paths which introduce the unreacted synthesis gas delivered from the top of the bubble column reactor 30 again into the bubble column reactor 30. Specifically, the second compression apparatus 120 is arranged on the downstream side of the gas-liquid separator 38. Also, the second compression apparatus 120 is arranged on the upstream side of a synthesis gas introducing port of the bubble column reactor 30 so that the gas 10 compressed in the second compression apparatus 120 may be introduced again into the bubble column reactor 30. Here, the pipeline 140 connected to the gas-liquid separator 38 and the pipelines 142 and 146 constitute a recycle path. [0055] Next, the first compression apparatus 110 and the second compression apparatus 120 will be described concretely. FIG. 3 is a schematic diagram showing the 15 configuration of the first compression apparatus 110 and the second compression apparatus 120 in the liquid fuel synthesizing system according to the present embodiment. [0056] The first compression apparatus 110 or the second compression apparatus 120, as shown in FIG. 3, is composed of a compressor 114, a motor part 116, and a steam 20 turbine 112. [0057] The compressor 114 is an apparatus which compresses gas by a driving device and continuously delivers the compressed gas. The compressor 114 has an inlet 114a and an outlet 114b for gas, introduces synthesis gas from the inlet 114a, and delivers the compressed synthesis gas from the outlet 114b. For example, a displacement type 25 compressor and a turbo type compressor can be used as the compressor 114. A OSP-27770AU 21 reciprocal compressor, a rotary compressor, etc. can be used as the displacement type compressor, and a centrifugal radial compressor, a turbo compressor, an axial compressor, etc. can be used as the turbo type compressor. [0058] The displacement type compressor first confines a fixed volume of gas in a 5 chamber, then reduces the volume in the chamber where the gas is confined, thereby increasing the pressure of the gas to compress the gas, and then discharges the compressed gas continuously to the outside. The turbo type compressor rotates an impeller received in a casing to give pressure and speed to gas depending on an increase in energy of the gas generated by the impeller, thereby compressing the gas, and 10 discharges the compressed gas continuously to the outside. [0059] A rotary shaft of the steam turbine 112 and a rotary shaft of the compressor 114 are connected to the motor part 116. The motor part 116 is driven by the torque of the steam turbine 112, and transmits the torque to the compressor 114 to drive the compressor 114. 15 [0060] The steam turbine 112 is a thermal engine which converts the thermal energy of steam into power. The steam turbine 112 is composed of a fixed stationary vane and a rotating movable vane, and applies a high-speed vapor stream generated in the stationary vane to the movable vane to rotate a rotor to which the movable vane is attached, thereby obtaining a driving force. The steam is introduced into an inlet 112a of the steam 20 turbine 112. As the steam turbine 112, a back-pressure turbine, a condensing turbine, or the like can be used. The back-pressure turbine discharges steam to an outlet 112b as gas, and the condensing turbine cools down steam at the outlet 112b by a cooler (not shown), thereby discharging as liquid water. [0061] The steam turbine 112 connected to the compressor 114 is driven using the 25 high-pressure steam extracted from the waste heat boiler 14 as a power source.

OSP-27770AU 22 Accordingly, a steam pipeline for introducing the high-pressure steam is connected to the steam turbine 112. This steam pipeline is provided so as to connect the gas-liquid separator 16, which removes the high-pressure steam extracted from the waste heat boiler 14, and the steam turbine 112. Further, the steam turbine 112 is provided with a 5 discharge port which discharges condensed water (condensate) into which the high-pressure steam is condensed by energy conversion. [0062] Next, the operation of the first compression apparatus 110 and the second compression apparatus 120 as supply destinations of the high-pressure steam in the liquid fuel synthesizing system 1 according to the present embodiment will be described with 10 reference to FIGS. 2 and 3. First, the operation of the first compression apparatus 110 that compresses the synthesis gas synthesized in the reformer 12 will be described below. The synthesis gas is supplied from the reformer 12, is then cooled down through the waste heat boiler 14, and is further introduced into the first compression apparatus 110 through the pipeline 150 as a supply path via the CO 2 removal unit 20. The first 15 compression apparatus 110 compresses the introduced synthesis gas. Specifically, the pressure of the synthesis gas is, for example, about 1.8 MPaG when being supplied from the reformer 12, and thereafter, the pressure of the synthesis gas is, for example, about 2.0 MPaG when being supplied from the CO 2 removal unit 20. Then, the pressure of the synthesis gas introduced into the first compression apparatus 110 rises to, for example, 20 3.6 MPaG. The synthesis gas supplied from the first compression apparatus 110 is introduced into the bubble column reactor 30. The pressure of the synthesis gas at this time becomes, for example, about 3.2 MPaG due to pressure losses of pipelines, etc. [0063] In order to improve the reaction rate of the FT synthesis reaction in the bubble column reactor 30, it is necessary to suitably set the pressure of the synthesis gas 25 introduced into the bubble column reactor 30, and to suitably adjust the reaction pressure OSP-27770AU 23 in the bubble column reactor 30. As described above, in the present embodiment, the synthesis gas, the pressure of which is raised to a predetermined reaction pressure or more, can be introduced into the bubble column reactor 30 by installing the first compression apparatus 110. Thus, the reaction pressure of the FT synthesis reaction can 5 be increased, and the reaction rate of the synthesis reaction can be improved. [0064] When the first compression apparatus 110 is not installed, the reaction pressure of the FT synthesis reaction in the bubble column reactor 30 becomes, for example, about 1.8 MPa or less, which is a pressure when the synthesis gas is supplied from the CO 2 removal unit 20, and the reaction rate of the source gas with the FT synthesis reaction is, 10 for example, about 50%. Also, in the present embodiment, the reaction pressure of the FT synthesis reaction is increased to, for example, about 3.2 MPaG by installing the first compression apparatus 110. Thus, the reaction rate of the source gas with the FT synthesis reaction can be increased to about 60% or more. [0065] Further, even if fluctuation or pulsation of the pressure of synthesis gas is caused 15 inside pipelines due to the operation of the waste heat boiler 14 or CO 2 removal unit 20 on the upstream side of the first compression apparatus 110, pressure losses of pipelines or valves, or the like, the first compression apparatus 110 can buffer any pressure fluctuation, etc. of the synthesis gas on the upstream side. Therefore, the first compression apparatus 110 can stably supply the synthesis gas, the pressure of which is 20 raised, to the downstream of the first compression apparatus 110. Accordingly, in the present embodiment, a stable pressure of synthesis gas can be supplied to the bubble column reactor 30 by installing the first compression apparatus 110 upstream of the synthesis gas introduction side of the bubble column reactor 30. As a result, since the reaction pressure of the FT synthesis reaction in the bubble column reactor 30 is also 25 stabilized, the FT synthesis reaction can be stabilized.

OSP-27770AU 24 [0066] Moreover, the first compression apparatus 110 is driven using the high-pressure steam generated from the waste heat boiler 14 as a power source. As described above, since a large amount of surplus high-pressure steam exists in the liquid fuel synthesizing system 1, this high-pressure steam can be utilized as a power source of the steam turbine 5 112 connected to the first compression apparatus 110. Moreover, consumption of electric power can be suppressed compared with a case where the power of the first compression apparatus 110 is used as electric power. As a result, the present embodiment can increase the energy efficiency of the whole liquid fuel synthesizing system 1. 10 [0067] Next, the operation of the second compression apparatus 120 that compresses unreacted synthesis gas delivered from the bubble column reactor 30 will be described below. In the bubble column reactor 30, not all the introduced synthesis gas reacts, but for example, about 40% of unreacted gas exists. After the unreacted synthesis gas is delivered from the top of the bubble column reactor 30, it passes through the pipelines 15 140, 142, and 146 via the gas-liquid separator 38, and is introduced again into the upstream of the bubble column reactor 30. The second compression apparatus 120 compresses this unreacted synthesis gas. Specifically, the pressure of the synthesis gas before being delivered from the top of the bubble column reactor 30 and being introduced into the second compression apparatus 120 is, for example, about 3.0 MPaG 20 Then, the pressure of the synthesis gas compressed by the second compression apparatus 120 rises to, for example, 3.6 MPaG. As a result, similarly to the case of the above-described first compression apparatus 110, the synthesis gas, the pressure of which is raised, can be introduced into the bubble column reactor 30, and the reaction pressure of the FT synthesis reaction in the bubble column reactor 30 can be increased. Also, the 25 reaction rate of the synthesis reaction can be improved.

OSP-27770AU 25 [0068] Further, similarly to the first compression apparatus 110, the second compression apparatus 120 can buffer any pressure fluctuation, etc. on the upstream side, and can supply a stable pressure of the synthesis gas to the introducing port of the bubble column reactor 30, which is on the downstream side. As a result, since the pressure in 5 the bubble column reactor 30 is stabilized, the FT synthesis reaction can be stabilized. [0069] The second compression apparatus 120 is driven by the steam turbine 112 using the high-pressure steam generated from the waste heat boiler 14 as a power source. Similarly to the first compression apparatus 110, the surplus high-pressure steam in the liquid fuel synthesizing system 1 can be utilized effectively and consumption of electric 10 power can be suppressed. Thus, the energy efficiency of the whole liquid fuel synthesizing system 1 can be enhanced. [0070] Next, the generator 134 driven by the steam turbine 132 will be described. First, the steam turbine 132 is connected to a steam piping system through which high-pressure steam flows. Specifically, steam piping is provided so as to connect the 15 gas-liquid separator 16 which removes the high-pressure steam discharged from the waste heat boiler 14, with the steam turbine 132. Also, the steam turbine 132 and the generator 134 are connected to each other so that the steam turbine 132 can transmit the power obtained by high-pressure steam to the generator 134. [0071] The steam turbine 132 is driven using the high-pressure steam generated from 20 the waste heat boiler 14 as a power source. When the steam turbine 132 rotates, the generator 134 can be driven to generate electric power. At this time, since the steam turbine 132 can be directly rotated, without reducing the pressure of the high-pressure steam, the energy held by the high-pressure steam can be utilized effectively. Further, since the surplus high-pressure steam discharged from the waste heat boiler 14 can be 25 utilized effectively, the energy efficiency of the whole liquid fuel synthesizing system 1 OSP-27770AU 26 can be increased. [0072] The electricity obtained by the generator 134 is supplied to and stored in, for example, a power storage facility 136 of the liquid fuel synthesizing system 1. The power storage facility 136 is electically connected to the generator 134 so as to store the 5 electric power obtained by the generator 134. Further, a transformer substation 138 is connected to each apparatus of the liquid fuel synthesizing system I so as to receive the electric power stored in the power storage facility 136 to supply the electric power to each apparatus of the liquid fuel synthesizing system 1. [0073] The electricity stored in the power storage facility 136 is supplied to each 10 apparatus in the liquid fuel synthesizing system I through the transformer substation 138. Specifically, the electricity generated in the generator 134 can be used for the first compression apparatus 110, the second compression apparatus 120, a pump for allowing fluid to flow, a blower when emission gas is emitted from the reformer 12, and the like. Further, the above electricity can also be used for, for example, rotating equipment, such 15 as a pump, when a carbon-dioxide absorbent is regenerated in the CO 2 removal unit 20. As a result, the energy efficiency of the whole liquid fuel synthesizing system 1 improves. [0074] Further, electric power can be stably supplied to the liquid fuel synthesizing system 1 by storing electricity in the power storage facility 136. That is, the stored 20 electricity can be used at the time of starting or during maintenance of the liquid fuel synthesizing system 1. Moreover, installation of the power storage facility 136 can prevent the liquid fuel synthesizing system 1 from being damaged at the time of emergency, such as interruption of electric power. For example, in a system which circulates steam, even at the time of interruption of electric power, cooling can be 25 performed by allowing a pump to run continuously. Thus, a temperature rise of OSP-27770AU 27 equipment or reactors, or damage of equipment or reactors caused by the temperature rise can be prevented. [0075] As described above, in the liquid fuel synthesizing system 1, in order to cool down high-temperature (for example, 900 to 1000 0 C) synthesis gas supplied from the 5 reformer 12 (for example, cooled down to about 400 0 C), a large amount of water is circulated in the waste heat boiler 14. Therefore, compared with a general plant facility, a large amount of high-pressure steam is generated. In the liquid fuel synthesizing system 1, as described above, this high-pressure steam is supplied to the reformer 12, and is utilized for reforming of the natural gas in the reformer 12. Further, the high-pressure 10 steam is also utilized for trace of pipelines or a temperature rise in every part of a plant facility, after its pressure is reduced. [0076] Moreover, in the liquid fuel synthesizing system 1, the high-pressure steam is generated in large quantities. Therefore, surplus high-pressure steam remains after the above utilization. Thus, the surplus high-pressure steam is recovered as water and is 15 discarded. In this case, the thermal energy held by the high-pressure steam will be consumed needlessly. Thus, the high-pressure steam generated from the waste heat boiler 14 is supplied to the first compression apparatus 110, the second compression apparatus 120, and the steam turbine 132 of the generator 134. As a result, the thermal energy of the high-pressure steam can be converted into power, and the high-pressure 20 steam can be utilized effectively. [0077] Although the preferred embodiments of the present invention have been described with reference to the accompanying drawings, it is needless to say that the present invention is not limited to such embodiments. It is apparent to those skilled in the art that various alternations or modifications can be made in the categories scope as 25 set forth in the claims, and it will be understood that these alternations or modifications OSP-27770AU 28 naturally belong to the technical scope of the present invention. [0078] For example, in the above embodiments, natural gas is used as a hydrocarbon raw material to be supplied to the liquid fuel synthesizing system 1. However, the present invention is not limited to such an example. For example, other hydrocarbon 5 raw materials, such as asphalt and residual oil, may be used. [0079] Further, in the above embodiments, liquid hydrocarbons are synthesized by the FT synthesis reaction as a synthesis reaction in the bubble column reactor 30. However, the present invention is not limited to this example. Specifically, the present invention can also be applied to, for example, oxo synthesis (hydroformylation reaction) 10 "R-CH=CH 2 + CO + H 2 -- R-CH 2

CH

2 CHO", methanol synthesis "CO + 2H 2 -+ CH30H", dimethylether (DME) synthesis "3CO + 3H 2 - CH30CH 3 + CO 2 ", etc., as the synthesis reaction in the bubble column reactor. [0080] Further, in the above embodiments, the slurry bubble column reactor is used as the reactor which synthesizes synthesis gas into liquid hydrocarbons. However, the 15 present invention is not limited to such an example. For example, an FT synthesis reaction using a fixed bed type reactor, etc. may be performed. [0081] Further, the above embodiment has showed an example in which the first compression apparatus 110 or the second compression apparatus 120 is driven by the steam turbine 112 using high-pressure steam as power. However, the present invention 20 is not limited to this example. For example, a power source may be connected to the motor part 116 of the first compression apparatus 110 so that the first compression apparatus 110 or the second compression apparatus 120 may be driven by electric power, and may be driven by combined use of steam and electric power. [0082] Further, the above embodiment has showed an example in which the steam 25 turbine 112 connected to the first compression apparatus 110 or the second compression OSP-27770AU 29 apparatus 120 uses the high-pressure steam extracted from the waste heat boiler 14 as a power source. However, the present invention is not limited to this example. For example, medium-pressure steam generated through a heat transfer pipe of the bubble column reactor 30 may be used as a power source. 5 INDUSTRIAL APPLICABILITY [0083] The present invention relates to a liquid fuel synthesizing system including: a reformer that reforms a hydrocarbon raw material to produce synthesis gas including carbon monoxide gas and hydrogen gas as main components; a reactor that synthesizes 10 liquid hydrocarbons from the carbon monoxide gas and hydrogen gas included in the synthesis gas; a supply path of the synthesis gas from the reformer to the reactor; and a first compression apparatus that is provided on the supply path to compress the synthesis gas produced by the reformer to at least more than a predetermined reaction pressure in the reactor. 15 According to the liquid fuel synthesizing system of the present invention, a stable reaction pressure required for the synthesis reaction in the reactor can be secured, and the reaction rate of the synthesis reaction can be improved.

Claims

1. A liquid fuel synthesizing system comprising: a reformer that reforms a hydrocarbon raw material to produce synthesis gas 5 including carbon monoxide gas and hydrogen gas as main components; a reactor that synthesizes liquid hydrocarbons from the carbon monoxide gas and hydrogen gas included in the synthesis gas; a supply path of the synthesis gas from the reformer to the reactor; and a first compression apparatus that is provided on the supply path to compress the 10 synthesis gas produced by the reformer to at least more than a predetermined reaction pressure in the reactor.

2. The liquid fuel synthesizing system according to Claim 1, further comprising a waste heat boiler that recovers the heat of the synthesis gas produced by the reformer to 15 generate steam, wherein the first compression apparatus is driven using the steam generated in the waste heat boiler as a power source.

3. The liquid fuel synthesizing system according to Claim 1, further comprising: 20 a recycle path that returns unreacted synthesis gas discharged from the reactor to an introducing port of the reactor; and a second compression apparatus that is provided on the recycle path to compress the unreacted synthesis gas to at least more than a predetermined reaction pressure in the reactor. 25 OSP-27770AU 31

4. The liquid fuel synthesizing system according to Claim 3, further comprising a waste heat boiler that recovers the heat of the synthesis gas produced by the reformer to generate steam, wherein the second compression apparatus is driven using the steam generated in the 5 waste heat boiler as a power source.

5. The liquid fuel synthesizing system according to Claim 1, further comprising: a waste heat boiler that recovers the heat of the synthesis gas produced by the reformer to generate steam, and 10 a generator that is driven using the steam generated in the waste heat boiler as a power source and that supplies electric power to each apparatus in the liquid fuel synthesizing system.

6. The liquid fuel synthesizing system according to Claim 5, wherein 15 the steam generated in the waste heat boiler is directly supplied to the generator from the waste heat boiler without a reduction in pressure thereof.