Hydrocarbon production apparatus and hydrocarbon production method

Abstract

To suppress the deterioration of the performance of a synthetic gas production means for producing a synthetic gas containing carbon monoxide and hydrogen.SOLUTION: A hydrocarbon production apparatus for producing hydrocarbons, the hydrocarbon production apparatus comprising: synthesis gas production means for producing a synthesis gas containing hydrogen and carbon monoxide by being supplied with steam and carbon dioxide; and hydrocarbon production means, provided downstream of the synthesis gas production means, for producing a mixed gas containing hydrocarbons from the synthesis gas, A hydrocarbon separation device that separates hydrocarbons from a mixed gas supplied from a hydrocarbon production device and discharges a residual gas from which the hydrocarbons have been removed, a residual gas return device that returns at least a portion of the residual gas discharged from the hydrocarbon separation device to a synthesis gas production device, and a steam flow rate adjustment device that adjusts the flow rate of steam supplied to the synthesis gas production device are provided.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a hydrocarbon production apparatus and a hydrocarbon production method, and is particularly suitable for application to a hydrocarbon production apparatus equipped with a synthesis gas generator that produces synthesis gas using water and carbon dioxide as raw materials. [Background technology]

[0002] Conventionally, carbon oxides (CO, CO2) and hydrogen (H2) are converted into hydrocarbons (C n H m Various hydrocarbon production apparatuses have been proposed that synthesize hydrocarbons (C). The hydrocarbon production apparatuses are provided with a synthesis gas generation unit that generates synthesis gas containing carbon monoxide (CO) and hydrogen (H) from water vapor (H2O) and carbon dioxide (CO2). The hydrocarbon production apparatus synthesizes hydrocarbons (C) from carbon monoxide (CO) and hydrogen (H2) contained in the generated synthesis gas. n H m ) is produced. In such a hydrocarbon production apparatus, a technology has been proposed in which, in a stage downstream of the synthesis gas production section, moisture (H2O) is separated by a water separation section, carbon dioxide (CO2) is separated by a carbon dioxide separation section, and the separated moisture and carbon dioxide are recycled to the synthesis gas production section (see Patent Document 1). Also, a technology has been proposed in which, in a hydrocarbon production apparatus, a portion of the gas discharged from the synthesis gas production section is extracted and recycled to the synthesis gas production section, thereby operating the synthesis gas production section in a reducing atmosphere (see Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-161124 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-152219 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned Patent Document 1, the gas supplied to the synthesis gas generator does not contain a reducing gas, which causes the electrodes of the synthesis gas generator to easily deteriorate, leading to a problem that the deterioration of the synthesis gas generator is likely to progress. Furthermore, in the above-mentioned Patent Document 2, the synthesis gas discharged from the synthesis gas generator contains carbon monoxide (CO). Therefore, if a portion of the synthesis gas is recirculated to the synthesis gas generator, a reduction reaction occurs in the synthesis gas generator, causing carbon to deposit on the electrode surfaces, which may lead to a deterioration in the performance of the synthesis gas generator. Therefore, there has been a need for a technology that can suppress the deterioration of the electrodes in the synthesis gas generator and thereby suppress the deterioration of the performance of the synthesis gas generator.

[0005] The present invention has been made in view of the above, and has an object to provide a hydrocarbon production apparatus and a hydrocarbon production method that can suppress deterioration in the performance of a synthesis gas production means that produces a synthesis gas containing carbon monoxide and hydrogen. [Means for solving the problem]

[0006] (1) In order to solve the above-mentioned problems and achieve the above-mentioned object, a hydrocarbon production apparatus according to one embodiment of the present invention is a hydrocarbon production apparatus for producing hydrocarbons from water vapor and carbon dioxide, comprising: synthesis gas generation means for receiving the water vapor and the carbon dioxide and producing a synthesis gas containing hydrogen and carbon monoxide; hydrocarbon generation means provided downstream of the synthesis gas generation means and producing a mixed gas containing hydrocarbons from the synthesis gas; hydrocarbon separation means provided downstream of the hydrocarbon generation means and separating hydrocarbons from the mixed gas supplied from the hydrocarbon generation means and discharging a residual gas from which the hydrocarbons have been removed from the mixed gas; residual gas return means configured to be able to return at least a portion of the residual gas discharged from the hydrocarbon separation means to the synthesis gas production means; and water vapor flow rate adjustment means configured to adjust the flow rate of the water vapor to a flow rate at which the mixed gas contains hydrogen and does not contain carbon oxides.

[0007] (2) In the hydrocarbon production apparatus according to one aspect of the present invention, in the invention (1) above, the steam flow rate adjusting means is configured to be able to adjust the flow rate of the steam to 7.0 times or more the flow rate of the carbon dioxide.

[0008] (3) In one aspect of the present invention, the hydrocarbon production apparatus according to the invention (1) or (2) above further includes a carbon dioxide flow rate adjustment means for adjusting the flow rate of the carbon dioxide supplied to the synthesis gas generation means, and the water vapor flow rate adjustment means is configured to be able to adjust the flow rate ratio of the water vapor to the flow rate of the carbon dioxide adjusted by the carbon dioxide flow rate adjustment means to a flow rate ratio in which the mixed gas contains hydrogen but does not contain carbon oxides.

[0009] (4) In one aspect of the present invention, the hydrocarbon production apparatus according to the invention (3) above further comprises a carbon dioxide flow rate derivation means for deriving the flow rate of carbon dioxide to be supplied to the synthesis gas generation means based on an input of a demand amount of hydrocarbons, and the carbon dioxide flow rate adjustment means is configured to be able to adjust the flow rate of the carbon dioxide to be supplied to the synthesis gas generation means based on a value derived by the carbon dioxide flow rate derivation means.

[0010] (5) A hydrocarbon production apparatus according to one embodiment of the present invention, in any one of the inventions (1) to (4) above, further comprises: a gas analysis means provided downstream of the hydrocarbon generation means and configured to be capable of detecting the hydrogen or carbon dioxide contained in the mixed gas generated by the hydrocarbon generation means; and a water vapor flow rate derivation means configured to be capable of deriving the flow rate of the water vapor to be adjusted by the water vapor flow rate adjustment means based on the measurement value of the flow rate of the hydrogen or the carbon dioxide measured by the gas analysis means, wherein the water vapor flow rate derivation means is configured to be capable of deriving the flow rate of the water vapor when the hydrogen is detected or when the carbon dioxide is not detected by the gas analysis means.

[0011] (6) In one embodiment of the hydrocarbon production apparatus according to any one of the above (1) to (5), the apparatus further comprises a water separation means configured to separate water contained in the gas downstream of the synthesis gas generation means and upstream of the hydrocarbon separation means.

[0012] (7) In accordance with one aspect of the present invention, in the above-described (6) invention, the hydrocarbon production apparatus further includes steam generating means for generating steam to be supplied to the synthesis gas generating means, and water returning means capable of supplying at least a portion of the water separated by the water separating means to the synthesis gas generating means.

[0013] (8) A hydrocarbon production method according to one aspect of the present invention is a hydrocarbon production method for producing hydrocarbons from steam and carbon dioxide, the method including: a synthesis gas production step of producing a synthesis gas containing hydrogen and carbon monoxide from the steam and the carbon dioxide by a synthesis gas production unit; a hydrocarbon production step of producing a mixed gas containing hydrocarbons from the synthesis gas after the synthesis gas production step; a hydrocarbon separation step of discharging a residual gas from a hydrocarbon separation unit that separates hydrocarbons from the mixed gas after the hydrocarbon production step, in which the hydrocarbons are separated from the mixed gas; a residual gas return step of returning at least a portion of the residual gas discharged from the hydrocarbon separation unit to the synthesis gas production unit; and a steam flow rate adjustment step of adjusting the flow rate of the steam to be supplied to the synthesis gas production unit to a flow rate such that the mixed gas contains hydrogen and does not contain carbon oxides.

[0014] (9) In the hydrocarbon production method according to one aspect of the present invention, in the invention (8) above, the flow rate of the steam is adjusted to 7.0 times or more the flow rate of the carbon dioxide in the steam flow rate adjusting step.

[0015] (10) In one aspect of the present invention, the hydrocarbon production method according to the invention (8) or (9) above further includes a carbon dioxide flow rate adjustment step of adjusting the flow rate of the carbon dioxide supplied to the synthesis gas production unit, and is configured so that the flow rate ratio of the water vapor to the flow rate of the carbon dioxide adjusted in the carbon dioxide flow rate adjustment step can be adjusted to a flow rate ratio in which the mixed gas contains hydrogen but does not contain carbon oxides.

[0016] (11) In one aspect of the present invention, the hydrocarbon production method according to the invention (10) above further includes a carbon dioxide flow rate derivation step of deriving the flow rate of the carbon dioxide to be supplied to the synthesis gas production unit based on an input of a demand amount of hydrocarbons, and in the carbon dioxide flow rate adjustment step, the flow rate of the carbon dioxide to be supplied to the synthesis gas production unit is adjusted based on the derived value of the flow rate of the carbon dioxide in the carbon dioxide flow rate derivation step.

[0017] (12) A hydrocarbon production method according to one aspect of the present invention is any one of the inventions (8) to (11) above, further including, after the hydrocarbon production step, a gas analysis step of detecting hydrogen or carbon dioxide contained in the mixed gas produced in the hydrocarbon production step, and a water vapor flow rate derivation step of deriving the flow rate of the water vapor in which hydrogen is detected or carbon dioxide is not detected in the gas analysis step based on the flow rate value of hydrogen or carbon dioxide measured in the gas analysis step.

[0018] (13) A hydrocarbon production method according to one aspect of the present invention is any one of the above (8) to (12), further comprising a water separation step configured to separate water contained in the gas after the synthesis gas generation step and before the hydrocarbon separation step.

[0019] (14) In accordance with one aspect of the present invention, the hydrocarbon production method of the above-described (13) further includes a steam generation step of generating steam to be supplied to the synthesis gas production unit, and a water return step of supplying at least a portion of the water separated in the water separation step to the synthesis gas production unit. [Effects of the Invention]

[0020] According to the hydrocarbon production apparatus and hydrocarbon production method of the present invention, it is possible to suppress deterioration in the performance of the synthesis gas production unit that produces synthesis gas containing carbon monoxide and hydrogen. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a block diagram showing a hydrocarbon production apparatus according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a graph showing the contents of hydrogen, carbon monoxide, and carbon dioxide at the outlet of the hydrocarbon production unit for each ratio of the flow rate of H2O to the flow rate of CO2 at the inlet of the synthesis gas production unit (H2O / CO2) in the hydrocarbon production apparatus according to the first embodiment of the present invention. [Figure 3] FIG. 3 is a block diagram showing a hydrocarbon production apparatus according to a second embodiment of the present invention. [Figure 4] FIG. 4 is a block diagram showing a hydrocarbon production apparatus according to a third embodiment of the present invention. [Figure 5] FIG. 5 is a block diagram showing a hydrocarbon production apparatus according to a fourth embodiment of the present invention. [Figure 6] FIG. 6 is a block diagram showing a hydrocarbon production apparatus according to a fifth embodiment of the present invention. [Figure 7] FIG. 7 is a block diagram showing a hydrocarbon production apparatus according to a sixth embodiment of the present invention. [Figure 8] FIG. 8 is a block diagram showing a hydrocarbon production apparatus according to a seventh embodiment of the present invention. [Figure 9] FIG. 9 is a block diagram showing a hydrocarbon production apparatus according to an eighth embodiment of the present invention. [Figure 10] FIG. 10 is a block diagram showing a hydrocarbon production apparatus according to a ninth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below. First, as an embodiment of the present invention, the inventors' intensive studies to solve the above-mentioned problems will be described.

[0023] First, the present inventors conducted various studies on the problems of the conventional technology. Specific examples of the conventional technology are disclosed in Patent Documents 1 and 2. Specifically, the inventors' studies revealed a problem with the hydrocarbon production technology described in Patent Document 1, in which the gas supplied to a synthesis gas generator that generates synthesis gas for hydrocarbon production does not contain a reducing gas, resulting in the deterioration of electrodes provided in the synthesis gas generator. Furthermore, the system requires multiple separation devices to separate specific gases from the mixed gas generated after hydrocarbon synthesis, resulting in the need for excessively large equipment. Furthermore, the hydrocarbon production apparatus described in Patent Document 2 contains carbon monoxide (CO) in the downstream gas downstream of the synthesis gas generator along the gas flow direction. Therefore, the present inventors discovered a problem that, when the downstream gas is recycled to the synthesis gas generator, carbon monoxide (CO) is supplied to the synthesis gas generator and reduced there, resulting in carbon deposition on the surfaces of the electrodes in the synthesis gas generator, potentially resulting in performance degradation.

[0024] The present inventors therefore conducted extensive research into ways to solve the problems they had discovered and came up with a method for supplying a reducing gas that does not contain carbon monoxide to the synthesis gas production section. This method makes it possible to suppress carbon deposition in the synthesis gas production section when circulating downstream gas downstream of the synthesis gas production section, thereby suppressing deterioration and extending the life of the device. Furthermore, it is possible to reduce the number of separation devices that separate specific gases from a mixed gas, which are installed downstream of the hydrocarbon production section that synthesizes and produces hydrocarbons, thereby saving the space required for the equipment in the hydrocarbon production system.

[0025] Specifically, the inventors have devised a method of increasing the flow rate of water vapor (H2O) supplied to the synthesis gas generation section relative to the flow rate of carbon dioxide (CO2) when circulating downstream gas downstream of the synthesis gas generation section. This allows the amount of hydrogen (H2) contained in the synthesis gas generated in the synthesis gas generation section to be greater than the amounts of carbon dioxide (CO2) and carbon monoxide (CO) (hereinafter referred to as carbon oxides). Therefore, the synthesis gas generated in the hydrocarbon generation section does not contain hydrocarbons (C n H m ), hydrogen (H2) and water (H2O) are contained, while carbon oxides (CO , In addition, hydrocarbons (C CO2) can be removed from the produced gas downstream of the hydrocarbon production section. n H m ) and circulate the reducing gas containing hydrogen (H2) to the synthesis gas generator, it is possible to suppress deterioration of the electrodes of the synthesis gas generator due to oxidation. In addition, since the reducing gas supplied to the synthesis gas generator does not contain carbon monoxide (CO), it is possible to suppress carbon deposition on the electrodes of the synthesis gas generator, thereby extending the life of the synthesis gas generator. Furthermore, since the mixed gas does not contain carbon oxides downstream of the hydrocarbon generator, it is possible to suppress the deposition of hydrocarbons (C n H m Since a separation device for separating the hydrocarbons from the carbon oxides is not required, space saving of the equipment in the hydrocarbon production plant can be realized. The embodiments described below have been devised by the inventors as a result of the above-mentioned intensive studies.

[0026] (First embodiment) Next, a first embodiment based on the above study by the present inventors will be described. Figure 1 is a block diagram showing a hydrocarbon production apparatus according to the first embodiment of the present invention.

[0027] (Hydrocarbon production equipment) As shown in FIG. 1, the hydrocarbon production apparatus 10A according to the first embodiment includes a carbon dioxide flow rate adjuster 11, a synthesis gas production unit 12, a hydrocarbon production unit 13, a hydrocarbon separation unit 14, a water vapor flow rate adjuster 15, a carbon dioxide flow rate calculation unit 16, and a residual gas return line 17.

[0028] The carbon dioxide flow rate adjusting unit 11, which serves as a carbon dioxide flow rate adjusting means for performing the carbon dioxide flow rate adjusting step, is configured to be able to adjust the flow rate of carbon dioxide (CO2) supplied from an external carbon dioxide storage unit (not shown) or the like, based on an instruction signal input from a carbon dioxide flow rate calculating unit 16 (described later).

[0029] The synthesis gas generation unit 12, which serves as synthesis gas generation means for performing the synthesis gas generation step, is composed of an electrolysis device such as a solid oxide electrolysis device. The synthesis gas generation unit 12 is an electrolysis reaction unit that electrolyzes at least a portion of the inflowing gas using electrodes. Carbon dioxide (CO2) whose flow rate is adjusted by the carbon dioxide flow rate adjuster 11, water vapor (H2O) whose flow rate is adjusted by the water vapor flow rate adjuster 15, and hydrogen (H2) are supplied to the synthesis gas generation unit 12. In the synthesis gas generation unit 12, a portion of the supplied H2O is electrolyzed into H2 and oxygen (O2) according to the following reaction formula (1), and a portion of the supplied CO2 is electrolyzed into CO and O2 according to the following reaction formula (2). The synthesis gas generation unit 12 is configured to be able to supply the generated synthesis gas containing H2 and CO to the hydrocarbon generation unit 13 together with H2O and CO2, and to be able to discharge the generated O2 to the outside. 2H2O → 2H2 + O2……(1) 2CO2 → 2CO+O2……(2)

[0030] The hydrocarbon production unit 13, which serves as hydrocarbon production means for performing the hydrocarbon production step, is composed of a catalytic reaction device such as a methanation device or an FT synthesis device. A synthesis gas containing hydrogen (H) and carbon monoxide (CO), water vapor (H0) and carbon dioxide (CO), are supplied to the hydrocarbon production unit 13. In the hydrocarbon production unit 13, hydrocarbons such as methane (CH) are synthesized by catalytic reactions, as shown in the following reaction formulas (3) and (4), for example. CO+3H2→CH4+H2O ……(3) CO2 + 4H2 → CH4 + 2H2O ……(4)

[0031] In addition, the Fischer-Tropsch (FT) synthesis reaction may be performed by changing at least one of the type of catalyst provided in the hydrocarbon production unit 13, the operating temperature, and the operating pressure. 10 ), pentane (CH 12 ), or hexane (CH 12 It is possible to synthesize various hydrocarbons such as olefinic hydrocarbons, paraffinic hydrocarbons, and olefinic hydrocarbons. The hydrocarbons (e.g., CH4) produced in the hydrocarbon production unit 13 are supplied to the hydrocarbon separation unit 14 as a mixed gas with hydrogen (H2) and water vapor (H2O).

[0032] The hydrocarbon separation section 14, which serves as hydrocarbon separation means for performing the hydrocarbon separation step, is composed of, for example, a membrane separator or a distillation column. The hydrocarbon separation section 14 is a hydrocarbon recovery section that separates and recovers hydrocarbons from the mixed gas supplied from the hydrocarbon production section 13. The residual gas containing water vapor (HO) and hydrogen (H) from which hydrocarbons have been removed in the hydrocarbon separation section 14 is discharged from the hydrocarbon separation section 14. At least a portion of the residual gas containing HO and H discharged from the hydrocarbon separation section 14 is supplied to the steam flow rate adjuster 15 through the residual gas return line 17. In other words, the residual gas return line 17, which serves as residual gas return means, is a supply line for performing the residual gas return step, in which at least a portion of the residual gas containing H and HO from which hydrocarbons have been removed from the hydrocarbon production section 13 is supplied to the upstream side of the synthesis gas production section 12 via the steam flow rate adjuster 15. Meanwhile, the hydrocarbons recovered from the hydrocarbon separation section 14 can be supplied to the outside.

[0033] The steam flow rate regulator 15, which serves as the steam flow rate regulator for executing the steam flow rate regulation step, is configured, for example, by a control valve. The steam flow rate regulator 15 regulates the flow rates of the supplied residual gas containing steam (HO) and hydrogen (H) and the externally supplied HO, and supplies them upstream of the synthesis gas generator 12. That is, the steam flow rate regulator 15 is configured to regulate the flow rate of HO supplied to the synthesis gas generator 12. Here, in this embodiment, the steam flow rate regulator 15 is configured to regulate the flow rate of HO to a flow rate at which carbon oxides (CO, CO) are not contained in the mixed gas discharged from the hydrocarbon generator 13. Preferably, the steam flow rate regulator 15 is configured to regulate the flow rate of steam supplied to the synthesis gas generator 12 to a flow rate at least 7.0 times the flow rate of CO.

[0034] The carbon dioxide flow rate calculation unit 16, which serves as carbon dioxide flow rate derivation means for executing the carbon dioxide flow rate derivation step, specifically includes a processor having hardware such as a CPU (Central Processing Unit), and a main storage unit such as a RAM (Random Access Memory) or a ROM (Read Only Memory) (neither of which are shown), and has software for calculating the carbon dioxide flow rate based on the demand for hydrocarbons input from the outside. As described above, the flow rate of carbon dioxide (CO2) supplied to the synthesis gas generation unit 12 is adjusted by the carbon dioxide flow rate adjustment unit 11. The carbon dioxide flow rate adjustment unit 11 controls the carbon dioxide flow rate adjustment unit 11 based on the demand for hydrocarbons input from the outside so that the flow rate of CO2 supplied to the synthesis gas generation unit 12 becomes the derived value of the CO2 flow rate calculated by the carbon dioxide flow rate calculation unit 16. In other words, the flow rate of CO2 supplied to the synthesis gas generation unit 12 is adjusted based on the carbon dioxide flow rate calculated by the carbon dioxide flow rate calculation unit 16.

[0035] (Hydrocarbon production method) Next, a hydrocarbon production method using the hydrocarbon production apparatus 10A configured as above will be described.

[0036] That is, as shown in Fig. 1, first, information on the demand for hydrocarbons is input from outside to the carbon dioxide flow rate calculation unit 16. Note that any method can be used to input information to the carbon dioxide flow rate calculation unit 16. The carbon dioxide flow rate calculation unit 16 derives the required flow rate of carbon dioxide (CO2) based on the input demand for hydrocarbons. The derived CO2 flow rate is output to the carbon dioxide flow rate adjustment unit 11.

[0037] Meanwhile, carbon dioxide (CO2) is supplied to the carbon dioxide flow rate adjuster 11 from the outside. The carbon dioxide flow rate adjuster 11 adjusts the flow rate of the supplied CO2 based on the input CO2 flow rate and supplies it to the synthesis gas production unit 12. Furthermore, the water vapor flow rate adjuster 15 is supplied with water vapor (H2O) from the outside, and hydrogen (H2) and H2O discharged from the hydrocarbon separation unit 14 are supplied to it via a residual gas return line 17. The water vapor flow rate adjuster 15 adjusts the flow rate of the supplied H2O and supplies it to the synthesis gas production unit 12, and also supplies the supplied H2 to the synthesis gas production unit 12. That is, the CO2 discharged from the carbon dioxide flow rate adjuster 11 and the H2O and H2 discharged from the water vapor flow rate adjuster 15 are joined together and supplied to the synthesis gas production unit 12.

[0038] Carbon dioxide (CO2) supplied from the carbon dioxide flow rate adjuster 11, and water vapor (H2O) and hydrogen (H2) supplied from the water vapor flow rate adjuster 15 flow into the synthesis gas generator 12. In the synthesis gas generator 12, at least a portion of the supplied CO2 and H2O is electrolyzed by electrodes in accordance with the above-described reaction formulas (1) and (2). That is, the synthesis gas generator 12 electrolyzes the supplied H2O and CO2, decomposing H2O into H2 and oxygen (O2) and decomposing CO2 into CO and O2. The synthesis gas generator 12 supplies the generated synthesis gas containing H2 and CO to the hydrocarbon generator 13 together with H2O and CO2, and discharges the generated O2 to the outside. In addition, since the H2 separated by the hydrocarbon separation section 14 is circulated to the inlet of the synthesis gas production section 12 through the residual gas return line 17, oxidation degradation of the electrodes (not shown) provided in the synthesis gas production section 12, which is an electrolysis device, can be suppressed.

[0039] The hydrocarbon production unit 13 receives synthesis gas containing hydrogen (H2) and carbon monoxide (CO), water vapor (H2O), and carbon dioxide (CO2) supplied from the synthesis gas production unit 12. In the hydrocarbon production unit 13, at least a portion of the supplied synthesis gas (H2, CO) and CO2 undergoes catalytic reactions, for example, according to the above-mentioned reaction formulas (3) and (4), to synthesize methane (CH4). The hydrocarbon production unit 13 supplies a mixed gas containing the produced hydrocarbons and the remainder of the H2O and H2 to the hydrocarbon separation unit 14.

[0040] Here, in this embodiment, the water vapor flow rate adjuster 15 adjusts the flow rate of water vapor (H2O) supplied to the synthesis gas generator 12 so that the mixed gas discharged from the hydrocarbon generator 13 contains hydrogen (H2) but does not contain carbon oxides (CO, CO2). As a result, the mixed gas discharged from the hydrocarbon generator 13 does not contain CO and CO2, and a CO and CO2 separator is not required downstream of the hydrocarbon generator 13. Furthermore, the flow rate of H2O is preferably set to a flow rate that is 7.0 times or more the flow rate of CO2 supplied to the synthesis gas generator 12. As a result, the composition of the gas flowing into the hydrocarbon generator 13 can be such that the flow rate of H2 is excessive relative to CO and CO2, and it becomes possible to produce hydrocarbons in the hydrocarbon generator 13 while causing the gas discharged from the hydrocarbon generator 13 to contain H2 but not CO and CO2.

[0041] The hydrocarbon separation unit 14 receives the hydrocarbons from the hydrocarbon production unit 13, including hydrogen (H2) and carbon oxides (CO , The hydrocarbon separation unit 14 separates and recovers hydrocarbons (e.g., CH4) from the mixed gas. The hydrocarbon separation unit 14 discharges residual gas containing water vapor (H2O) and hydrogen (H2) from which the hydrocarbons have been separated from the mixed gas. The residual gas containing H2 and H2O discharged from the hydrocarbon separation unit 14 is ,At least a portion of the residual gas not containing CO2 is supplied to the steam flow rate adjuster 15 through the residual gas return line 17 and recycled to the synthesis gas generator 12. In this manner, hydrocarbons are produced by the hydrocarbon production apparatus 10A.

[0042] (Flow ratio of carbon dioxide and steam supplied to the synthesis gas generation section) Next, the flow rate ratio of water vapor (H2O) to the flow rate of carbon dioxide (CO2) supplied to the synthesis gas production section 12 in the examples and comparative examples when hydrocarbons are produced by the hydrocarbon production apparatus 10A configured as above will be described.

[0043] First, the operating conditions of the hydrocarbon production apparatus 10A shown in FIG. 1 are set as follows. Reaction rate in synthesis gas generation section 12: 50% Temperature of the synthesis gas generation section 12: 800°C Pressure in hydrocarbon production section 13: 0.81 MPaA (8 atmA) Temperature of hydrocarbon production section 13: 250°C Temperature of hydrocarbon separation section 14: 40°C

[0044] Based on the above operating conditions, hydrocarbons were produced by changing the flow rate of carbon dioxide (CO2) flowing into the carbon dioxide flow rate regulator 11 (at the inlet of the carbon dioxide flow rate regulator), and the flow rates of hydrogen (H2), water vapor (H2O), and carbon dioxide (CO2) supplied to the synthesis gas production unit 12 (at the inlet of the carbon dioxide flow rate regulator). Figure 2 shows the hydrogen (H2) and carbon oxides (CO2) at the outlet of the hydrocarbon production unit 13 for each flow rate ratio of H2O to the CO2 flow rate at the inlet of the synthesis gas production unit 12 (H2O / CO2). , 1 is a graph showing the content of CO2.

[0045] (Example of methane production) A specific example of the above-described embodiment will be described. That is, an embodiment of a method for producing methane using the hydrocarbon production apparatus 10A configured as described above will be described. First, a predetermined amount of methane (CH4), 20 Nm 3In this embodiment, the carbon dioxide flow rate calculation unit 16 calculates the flow rate of carbon dioxide (CO2) required to generate carbon dioxide at a flow rate of 20 Nm3 / h. 3 / h was derived.

[0046] (Example) Next, the carbon dioxide flow rate regulator 11 regulates the carbon dioxide (CO2) to 20 Nm 3 The flow rate of hydrogen (H2) is adjusted so that it is supplied to the synthesis gas production unit 12 at a flow rate of 30 Nm3 / h. 3 In this example, the flow rate of CO2 is 20 Nm 3 / h, the flow rate of steam (H2O) supplied to the synthesis gas generator 12 is 10 times higher, 200 Nm 3 H2O was supplied to the synthesis gas generation unit 12 at a flow rate of 20 Nm3 / h. As time passed, methane (CH4) and residual gas (H2, H2O) were produced, and at least a portion of the residual gas was returned to the synthesis gas generation unit 12 via the residual gas return line 17. At the same time, the amount of hydrogen (H2) supplied and the amount of water vapor supplied at the time of startup were reduced. As a result, the flow rate of CO2 at the inlet of the carbon dioxide flow rate adjusting unit reached 20 Nm3. 3 / h, the flow rate of water vapor (H2O) at the inlet of the synthesis gas generation section is 140Nm 3 / h and steady operation is achieved at 20Nm 3 / h of methane (CH4) was obtained.

[0047] (Comparative Example) In the comparative example, the amount of hydrogen (H2) flowing into the synthesis gas generation unit 12 at startup was reduced compared to the example, and the flow rate of water vapor (H2O) was also set to less than 7.0 times (6.3 times, 4.0 times) the flow rate of carbon dioxide (CO2) flowing into the synthesis gas generation unit 12.

[0048] 2, it can be seen that in the example, the mixed gas supplied from the hydrocarbon production unit 13 to the hydrocarbon separation unit 14 contains hydrogen (H2), but does not contain carbon oxides (CO, CO2). In other words, by setting the flow rate ratio of H2O to the flow rate of CO2 supplied to the synthesis gas production unit 12 (H2O / CO2) to 7 or more, it is possible to prevent the mixed gas discharged from the hydrocarbon production unit 13 from containing CO and CO2.

[0049] In contrast, in the comparative example, the mixed gas flowing out from the hydrocarbon production unit 13 does not contain hydrogen (H2), but does contain carbon dioxide (CO2). In this case, the residual gas discharged from the hydrocarbon separation unit 14 and returned to the steam flow rate adjuster 15 via the residual gas return line 17 does not contain H2, making it difficult to maintain a reducing atmosphere at the electrode units in the synthesis gas production unit 12 and to suppress oxidative degradation of the electrode units. Furthermore, because the gas discharged from the hydrocarbon production unit 13 contains CO2, it becomes necessary to provide a device downstream for separating CO2.

[0050] Furthermore, in the embodiment, the residual gas discharged from the hydrocarbon separation section 14 and returned to the steam flow rate adjuster 15 via the residual gas return line 17 contains hydrogen (H2), so that the electrode section in the synthesis gas generator 12 can be made into a reducing atmosphere, thereby suppressing oxidation deterioration of the electrode section. Also, since the gas discharged from the hydrocarbon separation section 14 does not contain carbon oxides (CO, CO2), there is no need to provide a device for separating this CO and CO2, which allows for space saving of the equipment.

[0051] According to the first embodiment described above, the flow rate of water vapor (HO) supplied to the synthesis gas generation unit 12 is adjusted to a flow rate at which carbon oxides (CO, CO) are not contained in the mixed gas generated by the hydrocarbon generation unit 13, and the supply amount of hydrogen (H) supplied to the hydrocarbon generation unit 13 is made in excess of the flow rate of carbon dioxide (CO). As a result, the mixed gas discharged from the hydrocarbon generation unit 13 contains H but not CO or CO. Therefore, a reducing gas that does not contain carbon monoxide (CO) but contains H can be circulated to the synthesis gas generation unit 12 via the residual gas return line 17. This makes it possible to suppress carbon deposition in the synthesis gas generation unit 12 and to create a reducing atmosphere around the electrodes provided in the synthesis gas generation unit 12, thereby suppressing deterioration due to oxidation of the electrodes and achieving a longer life for the synthesis gas generation unit 12.

[0052] Furthermore, since the mixed gas discharged from the hydrocarbon production section 13 does not contain carbon oxides (CO, CO2), the number of separation devices required to separate CO and CO2 at the downstream of the hydrocarbon production section 13 can be reduced compared to conventional technology.

[0053] (Second embodiment) Next, a second embodiment of the present invention will be described below. Fig. 3 is a block diagram showing a hydrocarbon production apparatus according to the second embodiment.

[0054] (Hydrocarbon production equipment) 3, the hydrocarbon production apparatus 10B according to the second embodiment includes a carbon dioxide flow rate adjuster 11, a synthesis gas production unit 12, a hydrocarbon production unit 13, a hydrocarbon separation unit 14, a steam flow rate adjuster 15, a carbon dioxide flow rate calculation unit 16, a residual gas return line 17, a gas analysis unit 18, and a steam flow rate calculation unit 19. The carbon dioxide flow rate adjuster 11, the synthesis gas production unit 12, the hydrocarbon production unit 13, the hydrocarbon separation unit 14, the steam flow rate adjuster 15, the carbon dioxide flow rate calculation unit 16, and the residual gas return line 17 are the same as those in the first embodiment, and therefore description thereof will be omitted.

[0055] The gas analysis unit 18, which serves as gas analysis means for performing the gas analysis step, is composed of, for example, a catalytic combustion type or gas thermal conduction type hydrogen detector, or an infrared absorption analysis type carbon dioxide detector. In the second embodiment, the gas analysis unit 18 is provided between the hydrocarbon production unit 13 and the hydrocarbon separation unit 14. The gas analysis unit 18 can measure at least one of the concentrations of hydrogen (H2) and carbon dioxide (CO2).

[0056] The water vapor flow rate calculation unit 19, which serves as water vapor flow rate derivation means for executing the water vapor flow rate derivation step, is configured similarly to the carbon dioxide flow rate calculation unit 16 and has software for calculating the flow rate of water vapor (H2O) based on the measured values ​​of hydrogen (H2) or carbon dioxide (CO2) concentration input from the gas analysis unit 18. As described above, the flow rate of H2O supplied to the synthesis gas generation unit 12 is adjusted by the water vapor flow rate adjustment unit 15. The water vapor flow rate adjustment unit 15 is controlled based on the H2O flow rate derived by the water vapor flow rate calculation unit 19 based on the measured values ​​of H2 or CO2 input from the gas analysis unit 18. That is, the flow rate of H2O supplied to the synthesis gas generation unit 12 is adjusted based on the H2O flow rate derived by the water vapor flow rate calculation unit 19.

[0057] (Hydrocarbon production method) Next, a hydrocarbon production method using the hydrocarbon production apparatus 10B configured as above will be described. In the hydrocarbon production method according to the second embodiment, unlike the first embodiment, the mixed gas supplied from the hydrocarbon production section 13 to the hydrocarbon separation section 14 is analyzed by the gas analysis section 18. The gas analysis section 18 measures the concentration of hydrogen (H2) or carbon dioxide (CO2) contained in the mixed gas discharged from the hydrocarbon production section 13. The gas analysis section 18 outputs information on the measurement value to the water vapor flow rate calculation section 19.

[0058] The water vapor flow rate calculation unit 19 derives a water vapor (H2O) flow rate to be supplied to the synthesis gas production unit 12 that is necessary for H2 to be detected in the mixed gas, based on a measurement value of the concentration of hydrogen (H2) contained in the mixed gas discharged from the hydrocarbon production unit 13. Alternatively, the water vapor flow rate calculation unit 19 derives a water vapor (H2O) flow rate to be supplied to the synthesis gas production unit 12 that is necessary for CO2 not to be detected in the mixed gas, based on a measurement value of the concentration of carbon dioxide (CO2) contained in the mixed gas discharged from the hydrocarbon production unit 13. The water vapor flow rate calculation unit 19 outputs the derived value of the H2O flow rate to the water vapor flow rate adjustment unit 15.

[0059] As shown in FIG. 2, if the mixed gas discharged from the hydrocarbon production unit contains hydrogen (H), the mixed gas will not contain carbon oxides (CO, CO), and if the mixed gas does not contain carbon dioxide (CO), the mixed gas will contain H.

[0060] As described above, the flow rate of water vapor (H2O) supplied to the synthesis gas generation unit 12 is adjusted by the water vapor flow rate adjustment unit 15. Based on the derived value of the H2O flow rate input from the water vapor flow rate calculation unit 19, the water vapor flow rate adjustment unit 15 controls the water vapor flow rate adjustment unit 15 so that the flow rate of H2O supplied to the synthesis gas generation unit 12 becomes the derived value of the H2O flow rate derived by the water vapor flow rate calculation unit 19. In other words, the flow rate of H2O supplied to the synthesis gas generation unit 12 is adjusted based on the derived value of the H2O flow rate derived by the water vapor flow rate calculation unit 19.

[0061] As described above, when the mixed gas flowing into the hydrocarbon separation section 14 does not contain hydrogen (H2) but does contain carbon dioxide (CO2), the flow rate of H2O supplied to the synthesis gas production section 12 can be adjusted to an H2O flow rate at which H2 is contained in the mixed gas and CO2 is not detected. In this way, by adjusting the H2O flow rate to the minimum necessary flow rate at which H2 is contained in the mixed gas and carbon oxides (CO, CO2) are not detected, it is possible to reduce the size of each of the components that make up the hydrocarbon production apparatus 10B and the piping that connects each of the components. The other configurations of the second embodiment are the same as those of the first embodiment.

[0062] According to the second embodiment described above, the flow rate of steam supplied to the synthesis gas generation unit 12 can be adjusted depending on whether the mixed gas upstream of the hydrocarbon separation unit 14 contains hydrogen (H2) or carbon dioxide (CO2), so that the mixed gas contains H2 but does not contain carbon oxides (CO, CO2), thereby achieving the same effects as in the first embodiment. Furthermore, the concentration of H2 or CO2 contained in the mixed gas downstream of the hydrocarbon generation unit 13 is constantly measured by the gas analysis unit 18, and the flow rate of steam (H2O) supplied to the synthesis gas generation unit 12 can be reduced within a range in which H2 is detected but CO2 is not detected, thereby reducing the consumption of H2O supplied to the steam flow rate adjuster.

[0063] (Third embodiment) Next, a third embodiment of the present invention will be described below. Fig. 4 is a block diagram showing a hydrocarbon production apparatus according to the third embodiment.

[0064] (Hydrocarbon production equipment) 4, a hydrocarbon production apparatus 10C according to the third embodiment includes a carbon dioxide flow rate adjuster 11, a synthesis gas production unit 12, a hydrocarbon production unit 13, a hydrocarbon separation unit 14, a water vapor flow rate adjuster 15, a carbon dioxide flow rate calculation unit 16, a residual gas return line 17, a gas analysis unit 18, a water vapor flow rate calculation unit 19, and a water separation unit 20. The carbon dioxide flow rate adjuster 11, the synthesis gas production unit 12, the hydrocarbon production unit 13, the hydrocarbon separation unit 14, the water vapor flow rate adjuster 15, the carbon dioxide flow rate calculation unit 16, the residual gas return line 17, the gas analysis unit 18, and the water vapor flow rate calculation unit 19 are the same as those in the first and second embodiments, respectively.

[0065] The water separation unit 20, which serves as water separation means for performing the water separation step, is composed of, for example, a water condenser. The water separation unit 20 separates and removes at least a portion of moisture (HO) from the gas flowing therethrough, and in this embodiment, most of the HO from the gas, and discharges it to the outside. In the third embodiment, the water separation unit 20 is provided downstream of the hydrocarbon production unit 13 and upstream of the hydrocarbon separation unit 14, and is also provided downstream of the gas analysis unit 18. The water separation unit 20 separates and discharges HO from the mixed gas supplied from the hydrocarbon production unit 13. As a result, the mixed gas supplied to the hydrocarbon separation unit 14 does not contain HO, and therefore the residual gas discharged from the hydrocarbon separation unit 14 also does not contain HO. Therefore, in the third embodiment, unlike the first and second embodiments, the residual gas return line 17 is not connected to the steam flow rate adjuster 15, but is connected upstream of the synthesis gas production unit 12.

[0066] (Hydrocarbon production method) Next, a hydrocarbon production method using the hydrocarbon production apparatus 10C configured as above will be described. In the hydrocarbon production method according to the third embodiment, unlike the first and second embodiments, after hydrocarbons (CH4) are produced by the hydrocarbon production section 13, the mixed gas discharged from the hydrocarbon production section 13 is supplied to the water separation section 20. The water separation section 20 liquefies water vapor contained in the supplied mixed gas to produce liquid water, which is separated and removed. The mixed gas from which the water (H2O) has been removed is supplied to the hydrocarbon separation section 14, where the hydrocarbons are separated. Other configurations in the third embodiment are the same as those in the first and second embodiments.

[0067] According to the third embodiment described above, the configuration of the hydrocarbon production apparatus 10C is the same as that of the second embodiment except for the provision of the water separation section 20, and therefore the same effects as those of the second embodiment can be obtained. Furthermore, in the hydrocarbon production apparatus 10C according to the third embodiment, the water separation section 20 is provided upstream of the hydrocarbon separation section 14, and therefore the flow rate of the gas treated in the hydrocarbon separation section 14 can be reduced, and the hydrocarbon separation section 14 can be made more compact. Furthermore, since the residual gas does not contain moisture (HO) and the residual gas flowing through the residual gas return line 17 is a gas containing mainly hydrogen (H), the ratio of HO to H (water / hydrogen ratio) supplied to the synthesis gas production section 12 can be easily changed.

[0068] (Fourth embodiment) Next, a fourth embodiment of the present invention will be described below. Fig. 5 is a block diagram showing a hydrocarbon production apparatus according to the fourth embodiment.

[0069] (Hydrocarbon production equipment) 5, a hydrocarbon production apparatus 10D according to the fourth embodiment includes a carbon dioxide flow rate adjuster 11, a synthesis gas production unit 12, a hydrocarbon production unit 13, a hydrocarbon separation unit 14, a water vapor flow rate adjuster 15, a carbon dioxide flow rate calculation unit 16, a residual gas return line 17, a gas analysis unit 18, a water vapor flow rate calculation unit 19, and a water separation unit 20. The carbon dioxide flow rate adjuster 11, the synthesis gas production unit 12, the hydrocarbon production unit 13, the hydrocarbon separation unit 14, the water vapor flow rate adjuster 15, the carbon dioxide flow rate calculation unit 16, the residual gas return line 17, the gas analysis unit 18, and the water vapor flow rate calculation unit 19 are the same as those in the first and second embodiments, respectively.

[0070] The hydrocarbon production apparatus 10D according to the fourth embodiment differs from the second embodiment in that the water separation section 20 is provided downstream of the synthesis gas production section 12 and upstream of the hydrocarbon production section 13. By providing the water separation section 20 upstream of the hydrocarbon production section 13, water (HO) produced in the hydrocarbon production section 13 is not removed, and therefore the residual gas discharged from the hydrocarbon separation section 14 contains HO. Therefore, in the hydrocarbon production apparatus 10D according to the fourth embodiment, the residual gas return line 17 is connected to the steam flow rate adjuster 15, as in the first and second embodiments, and the residual gas discharged from the hydrocarbon separation section 14 is returned to the steam flow rate adjuster 15.

[0071] (Hydrocarbon production method) Next, a hydrocarbon production method using the hydrocarbon production apparatus 10D configured as above will be described. In the hydrocarbon production method according to the fourth embodiment, unlike the third embodiment, after synthesis gas (H2, CO) is produced by the synthesis gas production unit 12, H2, CO, water vapor (H2O), and carbon dioxide (CO2) discharged from the synthesis gas production unit 12 are supplied to the water separation unit 20. The water separation unit 20 liquefies the water vapor contained in the supplied gas to produce liquid water (H2O), which is separated and removed. The gas from which H2O has been removed is supplied to the hydrocarbon production unit 13, where hydrocarbons (CH4) are produced. The other configurations of the fourth embodiment are the same as those of the first and second embodiments.

[0072] The fourth embodiment described above is similar to the second embodiment except for the configuration in which the water separation section 20 is provided between the synthesis gas production section 12 and the hydrocarbon production section 13, and therefore can provide the same effects as the second embodiment. Furthermore, in the hydrocarbon production apparatus 10D according to the fourth embodiment, the water separation section 20 is provided upstream of the hydrocarbon production section 13, and therefore the flow rates of the synthesis gas and mixed gas treated in the hydrocarbon production section 13 and the hydrocarbon separation section 14, respectively, can be reduced, and the hydrocarbon production section 13 and the hydrocarbon separation section 14 can be made smaller.

[0073] (Fifth embodiment) Next, a fifth embodiment of the present invention will be described below. Fig. 6 is a block diagram showing a hydrocarbon production apparatus according to the fifth embodiment.

[0074] (Hydrocarbon production equipment) 6, a hydrocarbon production apparatus 10E according to the fifth embodiment includes a carbon dioxide flow rate adjuster 11, a synthesis gas production unit 12, a hydrocarbon production unit 13, a hydrocarbon separation unit 14, a water vapor flow rate adjuster 15, a carbon dioxide flow rate calculation unit 16, a residual gas return line 17, a gas analysis unit 18, a water vapor flow rate calculation unit 19, a first water separation unit 21, and a second water separation unit 22. The configurations of the carbon dioxide flow rate adjuster 11, the synthesis gas production unit 12, the hydrocarbon production unit 13, the hydrocarbon separation unit 14, the water vapor flow rate adjuster 15, the carbon dioxide flow rate calculation unit 16, the residual gas return line 17, the gas analysis unit 18, and the water vapor flow rate calculation unit 19 are the same as those of the first to third embodiments, respectively.

[0075] The configurations of the first water separation unit 21 and the second water separation unit 22 as water separation means for performing the water separation step are both similar to the configuration of the water separation unit 20 according to the third and fourth embodiments, and separate and remove at least a portion of the moisture (HO) from the gas flowing inside, in this embodiment, most of the HO from the gas, and discharge it to the outside. In the hydrocarbon production apparatus 10E according to the fifth embodiment, the first water separation unit 21 is provided downstream of the synthesis gas production unit 12 and upstream of the hydrocarbon production unit 13, i.e., between the synthesis gas production unit 12 and the hydrocarbon production unit 13. In addition, the second water separation unit 22 is provided downstream of the hydrocarbon production unit 13 and upstream of the hydrocarbon separation unit 14, i.e., between the hydrocarbon production unit 13 and the hydrocarbon separation unit 14.

[0076] As described above, the first water separation section 21 and the second water separation section 22 are provided at the upstream and downstream stages of the hydrocarbon production section 13, respectively, so that the mixed gas supplied to the hydrocarbon separation section 14 does not contain moisture (HO), and therefore the residual gas discharged from the hydrocarbon separation section 14 also does not contain HO. Therefore, in the hydrocarbon production apparatus 10E according to the fifth embodiment, the residual gas return line 17 is connected to the upstream side of the synthesis gas production section 12. The other configurations are the same as those of the second to fourth embodiments. In other words, the hydrocarbon production apparatus 10E according to the fifth embodiment is a hydrocarbon production apparatus that combines the hydrocarbon production apparatuses 10A, 10B, 10C, and 10D according to the first to fourth embodiments.

[0077] (Hydrocarbon production method) Next, a hydrocarbon production method using the hydrocarbon production apparatus 10E configured as above will be described. In the hydrocarbon production method according to the fifth embodiment, after synthesis gas is produced by the synthesis gas production unit 12, the synthesis gas (H2, CO), water vapor (H2O), and carbon dioxide (CO2) discharged from the synthesis gas production unit 12 are supplied to the first water separation unit 21. As in the fourth embodiment, the first water separation unit 21 liquefies the water vapor contained in the supplied gas to produce liquid water (H2O) and separates and removes it. The gas from which H2O has been removed is supplied to the hydrocarbon production unit 13, where hydrocarbons (CH4) are produced.

[0078] Next, after hydrocarbons (CH4) are produced by the hydrocarbon production unit 13, the mixed gas discharged from the hydrocarbon production unit 13 is supplied to the second water separation unit 22. The second water separation unit 22 liquefies the water vapor contained in the supplied mixed gas to produce liquid water (H2O), which is separated and removed. The mixed gas from which H2O has been removed is supplied to the hydrocarbon separation unit 14, where the hydrocarbons are separated. Other configurations of the fifth embodiment are the same as those of the first to fourth embodiments.

[0079] According to the fifth embodiment described above, the configuration is the same as that of the second embodiment except that the first water separation section 21 is provided between the synthesis gas production section 12 and the hydrocarbon production section 13, and the second water separation section 22 is provided between the hydrocarbon production section 13 and the hydrocarbon separation section 14. Therefore, the same effects as those of the second embodiment can be obtained, and both the hydrocarbon production section 13 and the hydrocarbon separation section 14 can be made smaller.

[0080] (Sixth embodiment) Next, a sixth embodiment of the present invention will be described below. Fig. 7 is a block diagram showing a hydrocarbon production apparatus according to the sixth embodiment.

[0081] (Hydrocarbon production equipment) 7, a hydrocarbon production apparatus 10F according to the sixth embodiment includes a carbon dioxide flow rate adjuster 11, a synthesis gas production unit 12, a hydrocarbon production unit 13, a hydrocarbon separation unit 14, a water vapor flow rate adjuster 15, a carbon dioxide flow rate calculation unit 16, a residual gas return line 17, a gas analysis unit 18, a water vapor flow rate calculation unit 19, a water separation unit 20, a water return line 23, and a water vapor production unit 24. The carbon dioxide flow rate adjuster 11, the synthesis gas production unit 12, the hydrocarbon production unit 13, the hydrocarbon separation unit 14, the water vapor flow rate adjuster 15, the carbon dioxide flow rate calculation unit 16, the residual gas return line 17, the gas analysis unit 18, the water vapor flow rate calculation unit 19, and the water separation unit 20 are each the same as those in the third embodiment.

[0082] The water return line 23, which serves as water return means for carrying out the water return step, is intended to supply the liquid water (H2O) separated and discharged by the water separation unit 20 to the steam generation unit 24. In other words, the water return line 23 is a supply line that supplies the H2O separated from the mixed gas supplied from the hydrocarbon generation unit 13 as a liquid to the upstream side of the steam generation unit 24. A partial discharge line 25 is provided midway along the water return line 23 to discharge a portion of the H2O.

[0083] The steam generation unit 24, which serves as steam generation means for performing the steam generation step, is composed of, for example, a boiler. The steam generation unit 24 generates steam (H2O) by heating liquid water (H2O) to vaporize it. The steam generation unit 24 is provided upstream of the steam flow rate regulator 15 along the flow of steam. In this embodiment, the steam flow rate regulator 15 can be composed of a steam flow rate control valve or the like. The steam generation unit 24 is supplied with H2O separated and discharged from the water separation unit 20 and liquid H2O from the outside. The steam (H2O) generated by the steam generation unit 24 has its flow rate adjusted by the steam flow rate regulator 15, and is then supplied to the synthesis gas generation unit 12.

[0084] (Hydrocarbon production method) Next, a hydrocarbon production method using the hydrocarbon production apparatus 10F configured as described above will be described. In the hydrocarbon production method according to the sixth embodiment, after hydrocarbons (CH4) are produced by the hydrocarbon production unit 13, the mixed gas discharged from the hydrocarbon production unit 13 is supplied to the water separation unit 20. The water separation unit 20 liquefies water vapor (H2O) contained in the mixed gas to produce liquid water (H2O). Unlike the third embodiment, the produced liquid H2O is supplied to the steam production unit 24 through a water return line 23. In the water return line 23, a portion of the water is discharged to the outside through a discharge line 25. The steam production unit 24 vaporizes the H2O supplied through the water return line 23 and the H2O supplied from the outside to produce water vapor (H2O). The produced water vapor is supplied to the steam flow rate adjustment unit 15, where the flow rate is adjusted, and then supplied to the synthesis gas production unit 12. The other configurations are the same as those of the third embodiment.

[0085] According to the sixth embodiment described above, the configuration is the same as that of the hydrocarbon production apparatus 10C according to the third embodiment, except for the provision of the steam generation section 24 that generates steam from liquid HO and the water return line 23 that returns the water (HO) separated and discharged from the water separation section 20 to the upstream side of the synthesis gas production section 12 via the steam generation section 24 and the steam flow rate adjuster 15. Therefore, the same effects as those of the first to third embodiments can be obtained, and the provision of the water return line 23 allows the discharged water to be effectively utilized.

[0086] (Seventh embodiment) Next, a seventh embodiment of the present invention will be described below. Fig. 8 is a block diagram showing a hydrocarbon production apparatus according to the seventh embodiment.

[0087] (Hydrocarbon production equipment) As shown in FIG. 8, the hydrocarbon production apparatus 10G according to the seventh embodiment, like the hydrocarbon production apparatus 10F according to the sixth embodiment, includes a carbon dioxide flow rate adjuster 11, a synthesis gas generator 12, a hydrocarbon generator 13, a hydrocarbon separator 14, a water vapor flow rate adjuster 15, a carbon dioxide flow rate calculator 16, a residual gas return line 17, a gas analyzer 18, a water vapor flow rate calculator 19, a water separator 20, a water return line 23, and a water vapor generator 24.

[0088] The hydrocarbon production apparatus 10G according to the seventh embodiment differs from the sixth embodiment in that a steam generation unit 24 is provided downstream of the steam flow rate adjuster 15 along the flow direction of water or steam (H2O). In other words, the steam flow rate adjuster 15 is provided upstream of the steam generation unit 24. The water return line 23 is for supplying liquid water (H2O) separated and discharged by the water separation unit 20 to the steam generation unit 24. In this embodiment, the water return line 23 is configured to be able to supply liquid H2O to the steam generation unit 24 through the steam flow rate adjuster 15. The steam flow rate adjuster 15 is configured, for example, by a water flow rate control valve, and is configured to be able to adjust the flow rate of steam (H2O) supplied to the synthesis gas generation unit 12 by adjusting the flow rate of liquid H2O supplied to the steam generation unit 24.

[0089] (Hydrocarbon production method) Next, a hydrocarbon production method using the hydrocarbon production apparatus 10G configured as above will be described. In the hydrocarbon production method according to the seventh embodiment, unlike the sixth embodiment, at least a portion of the water (H2O) separated in the water separation section 20 is supplied to the steam flow rate adjuster 15 through the water return line 23. The steam flow rate adjuster 15 adjusts the flow rate of liquid H2O to be supplied to the steam generation section 24 based on the derived value of the flow rate of gaseous H2O derived by the steam flow rate calculation section 19. The liquid H2O adjusted by the steam flow rate adjuster 15 is vaporized by the steam generation section 24 and supplied to the synthesis gas generation section 12 as gaseous H2O. The other configurations are the same as those of the sixth embodiment.

[0090] According to the seventh embodiment described above, the seventh embodiment is configured in the same manner as the sixth embodiment except that the steam generation unit 24 and the steam flow rate control unit 15 are arranged in the opposite direction to the sixth embodiment along the flow direction of HO, thereby achieving the same effects as the sixth embodiment. Furthermore, while the steam flow rate control unit 15 in the sixth embodiment is configured as a steam flow rate control valve, the steam flow rate control unit 15 in the seventh embodiment is configured as a water flow rate control valve. As a result, to control the same amount of water, the water flow rate control valve can be made smaller than the steam flow rate control valve, and therefore, the seventh embodiment can achieve space savings in the hydrocarbon production apparatus 10G compared to the sixth embodiment.

[0091] (Eighth embodiment) Next, an eighth embodiment of the present invention will be described below. Fig. 9 is a block diagram showing a hydrocarbon production apparatus according to the eighth embodiment.

[0092] (Hydrocarbon production equipment) 9, the hydrocarbon production apparatus 10H according to the eighth embodiment includes a carbon dioxide flow rate adjuster 11, a synthesis gas generator 12, a hydrocarbon production section 13, a hydrocarbon separation section 14, a water vapor flow rate adjuster 15 (15a, 15b), a carbon dioxide flow rate calculator 16, a residual gas return line 17, a gas analyzer 18, a water vapor flow rate calculator 19, a water separation section 20, a water return line 23, and a water vapor generator 24. The hydrocarbon production apparatus 10H according to the eighth embodiment has a configuration in which the hydrocarbon production apparatus 10D according to the fourth embodiment and the hydrocarbon production apparatus 10F according to the sixth embodiment are combined.

[0093] Specifically, the hydrocarbon production apparatus 10F includes a water separation unit 20 disposed downstream of the synthesis gas production unit 12 and upstream of the hydrocarbon production unit 13, and water (HO) discharged from the water separation unit 20 is supplied to a steam production unit 24 via a water return line 23. The steam flow rate adjuster 15 includes two steam flow rate adjusters 15a and 15b. Each of the steam flow rate adjusters 15a and 15b is formed, for example, by a steam flow rate control valve. One of the steam flow rate adjusters 15a is connected to a residual gas return line 17, and the other steam flow rate adjuster 15b is disposed downstream of the steam production unit 24. The steam flow rate calculator 19 outputs a derived value of the HO flow rate to the two steam flow rate adjusters 15a and 15b. The steam flow rate adjusters 15a and 15b may be integrated into one unit to form a single steam flow rate adjuster 15.

[0094] Furthermore, similar to the relationship between the hydrocarbon production apparatus 10F according to the sixth embodiment and the hydrocarbon production apparatus 10G according to the seventh embodiment, the locations of the steam flow rate adjuster 15b and the steam generator 24 may be reversed.

[0095] (Hydrocarbon production method) A hydrocarbon production method using the hydrocarbon production apparatus 10H configured as above will be described. In the hydrocarbon production method according to the eighth embodiment, hydrocarbons are also produced by a combination of the methods of the fourth and sixth embodiments.

[0096] According to the eighth embodiment described above, since the eighth embodiment has a configuration that combines the fourth and sixth embodiments, it is possible to obtain the same effects as the fourth and sixth embodiments.

[0097] (Ninth embodiment) Next, a ninth embodiment of the present invention will be described below. Fig. 10 is a block diagram showing a hydrocarbon production apparatus according to the ninth embodiment.

[0098] (Hydrocarbon production equipment) As shown in FIG. 10 , a hydrocarbon production apparatus 10J according to the ninth embodiment includes a carbon dioxide flow rate adjuster 11, a synthesis gas generator 12, a hydrocarbon generator 13, a hydrocarbon separator 14, a water vapor flow rate adjuster 15, a carbon dioxide flow rate calculator 16, a residual gas return line 17, a gas analyzer 18, a water vapor flow rate calculator 19, a first water separation unit 21, a second water separation unit 22, water return lines 23, 23 a, 23 b, and a water vapor generator 24, similar to those of the fifth embodiment.

[0099] Each of the first water separation section 21 and the second water separation section 22 liquefies and separates at least a portion of water (HO), in this embodiment, most of the HO, from the gas flowing therethrough, and discharges the separated water to the outside. In the hydrocarbon production apparatus 10J according to the ninth embodiment, the water return lines 23a and 23b are configured to be able to supply liquid HO discharged from the first water separation section 21 and the second water separation section 22 to the steam generation section 24, respectively. That is, the liquid HO discharged from the first water separation section 21 is supplied to the steam generation section 24 through the water return line 23a, and the liquid HO discharged from the second water separation section 22 is supplied to the steam generation section 24 through the water return line 23b. Although the water return lines 23a and 23b are joined in FIG. 10 , they may be configured to be independent and able to supply liquid HO to the steam generation section 24. Note that only one of the water return lines 23a, 23b may be provided, and H2O may be supplied to the steam generation section 24 from only one of the first water separation section 21 and the second water separation section 22. Also, a partial discharge line 25 may be provided midway through the water return lines 23a, 23b, or the partial discharge line 25 may be provided in the water return line 23 after the junction.

[0100] Furthermore, similar to the relationship between the hydrocarbon production apparatus 10F according to the sixth embodiment and the hydrocarbon production apparatus 10G according to the seventh embodiment, the locations of the steam flow rate adjuster 15 and the steam generator 24 may be reversed.

[0101] (Hydrocarbon production method) Next, a hydrocarbon production method using the hydrocarbon production apparatus 10J configured as described above will be described. In the hydrocarbon production method according to the ninth embodiment, unlike the fifth embodiment, the water (H2O) separated and discharged from the first water separation section 21 and the liquid H2O separated and discharged from the second water separation section 22 are joined together or supplied independently to the steam generation section 24. In the water return line 23 (23a, 23b), a portion of the water is discharged to the outside through the partial discharge line 25. The steam generation section 24 vaporizes the supplied H2O to generate steam (H2O), which is supplied to the steam flow rate adjustment section 15, where the flow rate is adjusted, and then supplied to the synthesis gas generation section 12. The other configurations are the same as those of the fifth and sixth embodiments.

[0102] The ninth embodiment described above is the same as the fifth and sixth embodiments except that liquid H2O is supplied to the steam generating section 24 from the first water separation section 21 and the second water separation section 22, respectively, and therefore can obtain the same effects as the fifth and sixth embodiments.

[0103] Further advantages and modifications will readily occur to those skilled in the art. The invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

[0104] For example, in the above-described embodiment, an example in which methane (CH4) is generated by the hydrocarbon generation unit 13 is described. However, the hydrocarbons generated are not necessarily limited to CH4, and other hydrocarbons (C n H m ) may also be used.

[0105] Furthermore, the gas analysis means configured to be capable of detecting hydrogen may be gas analysis means configured to be capable of detecting carbon dioxide, and in this case, the water vapor flow rate derivation means may be configured to be able to derive the flow rate of water vapor so that carbon dioxide is not detected by the gas analysis means. In this case, the method may include a water vapor flow rate derivation step of deriving the flow rate of water vapor by the water vapor flow rate derivation means so that carbon dioxide is not detected by the gas analysis means. [Explanation of symbols]

[0106] 10A, 10B, 10C, 10D, 10E, 10F, 10G, 10H, 10J Hydrocarbon production equipment 11 Carbon dioxide flow control section 12. Syngas generation section 13 Hydrocarbon Production Section 14 Hydrocarbon Separation Section 15, 15a, 15b Steam flow rate adjusting section 16 Carbon dioxide flow calculation unit 17 Residual gas return line 18 Gas Analysis Section 19 Water vapor flow rate calculation section 20 Water separation section 21 First water separation section 22 Second water separation section 23, 23a, 23b Water return line 24 Steam generation unit 25 Partial discharge line

Claims

1. A hydrocarbon production apparatus for producing hydrocarbons from steam and carbon dioxide, a synthesis gas generating means for generating a synthesis gas containing hydrogen and carbon monoxide when supplied with the water vapor and the carbon dioxide; a hydrocarbon generating means provided downstream of the synthesis gas generating means for generating a mixed gas containing hydrocarbons from the synthesis gas; a hydrocarbon separation means provided downstream of the hydrocarbon production means, which separates hydrocarbons from the mixed gas supplied from the hydrocarbon production means and discharges a residual gas remaining after the hydrocarbons have been removed from the mixed gas; a residual gas returning means configured to return at least a portion of the residual gas discharged from the hydrocarbon separation means to the synthesis gas generating means; a steam flow rate adjusting means for adjusting the flow rate of the steam supplied to the synthesis gas generating means, The water vapor flow rate adjusting means is configured to adjust the flow rate of the water vapor to a flow rate at which the mixed gas contains hydrogen and does not contain carbon oxides. Hydrocarbon production equipment.

2. The water vapor flow rate adjusting means is configured to adjust the flow rate of the water vapor to 7.0 times or more the flow rate of the carbon dioxide. The hydrocarbon production apparatus according to claim 1 .

3. further comprising a carbon dioxide flow rate adjusting means for adjusting the flow rate of the carbon dioxide supplied to the synthesis gas generating means; The water vapor flow rate adjusting means is configured to adjust the flow rate ratio of the water vapor to the flow rate of the carbon dioxide adjusted by the carbon dioxide flow rate adjusting means to a flow rate ratio in which the mixed gas contains hydrogen and does not contain carbon oxides. The hydrocarbon production apparatus according to claim 1 .

4. further comprising a carbon dioxide flow rate derivation means for deriving a flow rate of carbon dioxide to be supplied to the synthesis gas generation means based on an input of a demand amount of hydrocarbons; The carbon dioxide flow rate adjusting means is configured to be able to adjust the flow rate of the carbon dioxide supplied to the synthesis gas generating means based on the value derived by the carbon dioxide flow rate deriving means. The hydrocarbon production apparatus according to claim 3 .

5. a gas analysis means provided downstream of the hydrocarbon generation means and configured to be able to detect hydrogen or carbon dioxide contained in the mixed gas generated by the hydrocarbon generation means; and a water vapor flow rate deriving means configured to be able to derive the flow rate of the water vapor to be adjusted by the water vapor flow rate adjusting means based on the measurement value of the flow rate of the hydrogen or the carbon dioxide measured by the gas analyzing means, The water vapor flow rate deriving means is configured to be able to derive the flow rate of the water vapor when the hydrogen is detected by the gas analyzing means or when the carbon dioxide is not detected by the gas analyzing means. The hydrocarbon production apparatus according to claim 1 .

6. a water separation means configured to separate water contained in the gas, the water separation means being disposed downstream of the synthesis gas generation means and upstream of the hydrocarbon separation means; The hydrocarbon production apparatus according to claim 1 .

7. steam generating means for generating steam to be supplied to the synthesis gas generating means; and a water return means capable of supplying at least a portion of the water separated by the water separation means to the synthesis gas generation means. The hydrocarbon production apparatus according to claim 6 .

8. A method for producing hydrocarbons from steam and carbon dioxide, comprising: a synthesis gas generating step of generating synthesis gas containing hydrogen and carbon monoxide from the water vapor and the carbon dioxide by a synthesis gas generating unit; a hydrocarbon production step of producing a mixed gas containing hydrocarbons from the synthesis gas after the synthesis gas production step; a hydrocarbon separation step of discharging a residual gas from a hydrocarbon separation unit that separates hydrocarbons from the mixed gas after the hydrocarbon production step; a residual gas returning step of returning at least a portion of the residual gas discharged from the hydrocarbon separation unit to the synthesis gas production unit; a steam flow rate adjusting step of adjusting the flow rate of the steam supplied to the synthesis gas generating unit to a flow rate at which the mixed gas contains hydrogen and does not contain carbon oxides. Hydrocarbon production methods.

9. In the water vapor flow rate adjusting step, the flow rate of the water vapor is adjusted to 7.0 times or more the flow rate of the carbon dioxide. The hydrocarbon production method according to claim 8.

10. The method further includes a carbon dioxide flow rate adjusting step of adjusting the flow rate of the carbon dioxide supplied to the synthesis gas generator, The flow rate ratio of the water vapor to the flow rate of the carbon dioxide adjusted in the carbon dioxide flow rate adjustment step is configured to be adjustable to a flow rate ratio in which the mixed gas contains hydrogen and does not contain carbon oxides. The hydrocarbon production method according to claim 8.

11. further comprising a carbon dioxide flow rate deriving step of deriving a flow rate of the carbon dioxide to be supplied to the synthesis gas production unit based on an input of a demand amount of hydrocarbons; In the carbon dioxide flow rate adjusting step, the flow rate of the carbon dioxide supplied to the synthesis gas generating unit is adjusted based on the derived value of the flow rate of the carbon dioxide in the carbon dioxide flow rate derivation step. The hydrocarbon production method according to claim 10.

12. a gas analysis step, after the hydrocarbon production step, of detecting hydrogen or carbon dioxide contained in the mixed gas produced in the hydrocarbon production step; and a water vapor flow rate deriving step of deriving the flow rate of the water vapor in which hydrogen is detected or carbon dioxide is not detected in the gas analysis step based on the measurement value of the flow rate of hydrogen or carbon dioxide measured in the gas analysis step. The hydrocarbon production method according to claim 8.

13. The method further includes a water separation step configured to separate water contained in the gas after the synthesis gas generation step and before the hydrocarbon separation step. The hydrocarbon production method according to claim 8.

14. a steam generating step of generating steam to be supplied to the synthesis gas generating unit; and a water return step of supplying at least a portion of the water separated by the water separation step to the synthesis gas production unit. The hydrocarbon production method according to claim 13.

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