Methods for manufacturing valuable materials

Abstract

To provide a method for manufacturing valuable materials that can produce valuable materials more efficiently. [Solution] According to one aspect of the present invention, a method for producing a valuable substance is provided, comprising: a first step of preparing a raw material gas containing carbon monoxide, carbon dioxide, and hydrogen; a second step of separating and recovering a separated gas containing carbon dioxide from the raw material gas; a third step of removing impurities from the separated gas; a fourth step of converting the carbon dioxide in the separated gas from which impurities have been removed into carbon monoxide and oxygen to produce a converted gas, while removing oxygen from the converted gas; a fifth step of combining the raw material gas from which the separated gas has been separated and the converted gas from which oxygen has been removed to produce a combined gas; and a sixth step of producing a valuable substance from the combined gas, wherein the impurities include substances that adversely affect the conversion reaction of carbon dioxide into carbon monoxide and oxygen.

Description

[Technical Field]

[0001] This invention relates to a method for producing valuable materials. [Background technology]

[0002] In recent years, the massive consumption of oils and alcohols produced from petroleum has led to concerns about the depletion of fossil fuel resources and global environmental problems such as the increase in carbon dioxide in the atmosphere. To address these issues, methods for producing organic substances using raw materials other than petroleum, such as the production of bioethanol from edible raw materials like corn through sugar fermentation, are attracting attention. Such sugar fermentation methods using edible raw materials may lead to soaring food prices because they require the use of limited farmland for non-food production. Therefore, methods are being considered to produce organic substances that were previously manufactured from petroleum using waste materials (garbage) that would otherwise be discarded.

[0003] For example, Patent Document 1 discloses a manufacturing system for producing organic substances by partially oxidizing waste as a carbon source to generate synthesis gas containing carbon monoxide, and then fermenting this synthesis gas with microorganisms. In this manufacturing system, methane is produced from wastewater generated within the system, and carbon monoxide is obtained by reforming the methane, or by using hydrogen separated from synthesis gas to reduce carbon dioxide in the synthesis gas. The aim is to increase the yield of organic matter by using this carbon monoxide for microbial fermentation. However, there is currently a need to develop methods for producing organic substances (valuable materials) more efficiently. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2024 / 005184 [Overview of the project] [Problems that the invention aims to solve]

[0005] In view of the above circumstances, the present invention aims to provide a method for manufacturing valuable materials that can produce valuable materials more efficiently. [Means for solving the problem]

[0006] According to one aspect of the present invention, a method for producing a valuable substance is provided, comprising: a first step of preparing a raw material gas containing carbon monoxide, carbon dioxide, and hydrogen; a second step of separating and recovering a separated gas containing carbon dioxide from the raw material gas; a third step of removing impurities from the separated gas; a fourth step of converting the carbon dioxide in the separated gas from which impurities have been removed into carbon monoxide and oxygen to produce a converted gas, while simultaneously removing oxygen from the converted gas; a fifth step of combining the raw material gas from which the separated gas has been separated and the converted gas from which oxygen has been removed to produce a combined gas; and a sixth step of producing a valuable substance from the combined gas, wherein the impurities include substances that adversely affect the conversion reaction of carbon dioxide into carbon monoxide and oxygen.

[0007] According to this configuration, valuable materials can be manufactured more efficiently. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing the configuration of a manufacturing system that can be used in the manufacturing of valuable materials. [Modes for carrying out the invention]

[0009] The method for manufacturing valuable materials will be described in detail below based on the preferred embodiment shown in the attached drawings. Figure 1 is a schematic diagram showing the configuration of a manufacturing system that can be used for manufacturing valuable materials. The valuable product manufacturing system 100 shown in FIG. 1 (hereinafter, also simply referred to as "manufacturing system 100") includes a gasification furnace (gas generation unit that generates raw material gas) 10 and a valuable product manufacturing apparatus 1 (hereinafter, also simply referred to as "manufacturing apparatus 1") connected to the gasification furnace 10. In this specification, the upstream side with respect to the flow direction of gas and liquid is simply described as "upstream side", and the downstream side is simply described as "downstream side".

[0010] In the present embodiment, the gasification furnace 10 is not particularly limited, and examples thereof include a fluidized bed furnace, a kiln furnace, a shaft furnace, and the like. The gas generation unit may be a combustion furnace (incinerator), a paper mill, a cement factory, a thermal power plant, an essential oil plant, an ethylene cracker, an oil refinery, a chemical factory, or at least one business site selected from blast furnaces, converters, or electric furnaces (electric arc furnaces) in an ironworks, and may be a CO X emission source. In each furnace, a raw material gas (hereinafter, also simply referred to as "raw material gas") containing carbon monoxide, carbon dioxide, and hydrogen is generated (produced) during combustion, melting, refining, etc. of the contents.

[0011] In the case of a combustion furnace or a gasification furnace 10 in a waste incineration plant, examples of the contents (waste) include plastic waste, food waste, municipal solid waste (MSW), industrial waste, waste tires, biomass waste, household waste (quilts, papers), building materials, and the like. These wastes may contain one type alone or two or more types. In the case of a blast furnace, a converter, or an electric furnace in an ironworks, for example, a raw material gas is generated (produced) when heating iron ore together with coke, limestone, etc. In the case of a chemical factory, for example, a raw material gas is generated (produced) when steam reforming methane or when debinding during the manufacture of a ceramic sintered body.

[0012] The carbon in the raw material gas derived from waste, etc. is different from the carbon in petroleum in terms of the abundance ratio of carbon isotopes such as 14 C, 13 C (for example, δ 14 C, δ 13The value of C) is different. Therefore, the abundance ratio of carbon isotopes contained in the valuable product produced by the production system 100 from such a raw material gas is also different from that of the valuable product derived from petroleum. Therefore, even if the valuable product produced by the production system 100 is converted into other compounds and used, it can be discriminated (traced) that it is derived from the valuable product generated by the method with low environmental load by the production system 100.

[0013] In addition to carbon monoxide, carbon dioxide and hydrogen, the raw material gas may usually contain other gas components such as impurities, nitrogen, oxygen, water vapor, methane, etc. The impurities include solid impurities, gaseous impurities, water-soluble impurities, etc. Specific examples of the impurities include soot, tar, nitrogen compounds, sulfur compounds, phosphorus compounds, aromatic compounds, etc. The raw material gas may be generated as a gas containing 10% by volume or more of carbon monoxide by performing a heat treatment (commonly called gasification) for incompletely burning the content (carbon source) (that is, partially oxidizing the carbon source). If a valuable product is produced using such a raw material gas, carbon dioxide that has been conventionally discharged into the atmosphere can be effectively utilized, and the environmental load can be reduced. From the viewpoint of carbon circulation, it is preferable to use the exhaust gas generated in a combustion furnace or a smelter as the raw material gas.

[0014] The gasification furnace 10 may have an oxygen generation device that generates oxygen necessary for combustion. Examples of the oxygen generation device include a cryogenic separation type device capable of compressing, cooling, and liquefying air in the atmosphere to extract liquefied oxygen, liquefied nitrogen, etc. It is preferable to utilize the heat absorption when the obtained liquefied nitrogen vaporizes in the part of the production system 100 that requires cooling. In addition, the nitrogen gas obtained by vaporizing the liquefied nitrogen can be suitably used as the purge gas etc. of each part of the production system 100.

[0015] Further, the gasification furnace 10 may have a reforming area for reforming the raw material gas inside or outside thereof. The reforming area converts hydrocarbons (methane, ethane, char, tar, dioxins, etc.) contained in the raw material gas into carbon monoxide and hydrogen by, for example, keeping the raw material gas at a high temperature. At this time, a combustion-supporting gas such as oxygen or air may be supplied to raise the temperature. Furthermore, some of the carbon monoxide may be converted to carbon dioxide by reacting with oxygen. The temperature is preferably 1000°C or higher, and more preferably 1100°C to 1400°C.

[0016] In the reforming area, a method may be employed in which hydrocarbons such as methane contained in the raw gas are reacted with water vapor at high temperature in the presence of a catalyst to convert them into carbon monoxide and hydrogen. At this time, some of the carbon monoxide may be further converted into carbon dioxide and hydrogen by reacting with water vapor. The reaction temperature is preferably between 500°C and 1200°C. Examples of catalysts include metal catalysts. These metal catalysts include, for example, nickel catalysts, nickel oxide catalysts, ruthenium catalysts, rhodium catalysts, palladium catalysts, and platinum catalysts.

[0017] Here, the stable isotope ratio of carbon δ 13 It is known that carbon (C) tends to have a higher value under high-temperature combustion conditions and a lower value under incomplete combustion conditions. Therefore, by providing a reforming area, the raw material gas can be reformed to produce a unique δ (δ) according to the combustion conditions. 13 It may have a C value. Therefore, even if the valuable material produced by the manufacturing system 100 is converted into other compounds and used, it can be identified (trace) that it originated from the valuable material produced by the manufacturing system 100 using an environmentally friendly method.

[0018] The raw gas (synthesis gas) generated by the gasifier 10 is at a high temperature. The heat of this high-temperature raw gas may be utilized to generate steam from water. For example, a tank storing water may be provided in the middle of the gas line GL1 connected to the downstream side of the gasifier 10, and steam may be generated by heat exchange between the raw gas and water. Further, a heat recovery device (for example, an economizer, a heat pump, etc.) that is more suitable for recovering the high temperature heat provided near the gas line GL1 near the outlet of the gasifier 10 may be used to generate steam by heat exchange with the raw gas. Thus, by efficiently recovering and utilizing the heat of the raw gas without any waste, the environmental load during the production of valuable substances can be further reduced. Note that the heat of the raw gas is not limited to the utilization for the above purposes and can be utilized for various purposes. Also, the heat of the gas discharged from the reforming area may be recovered. As a heat recovery method, when a scrubber is used for cooling, the heat energy recovered through the scrubber may be utilized.

[0019] Such a gasifier 10 is connected to a manufacturing apparatus 1. This manufacturing apparatus 1 includes a culture tank (valuable substance generation unit) 2, a purification apparatus 6, a gas line GL1 connecting the gasifier 10 and the culture tank 2, and a liquid line LL connecting the culture tank 2 and the purification apparatus 6. In the culture tank 2, valuable substances are generated using microorganisms (particularly, gas-assimilating bacteria or algae) from the processed raw gas (the merged gas described later). That is, in the culture tank 2, valuable substances are generated by microbial fermentation of the raw gas.

[0020] Here, since the valuable substances generated in the culture tank 2 are generated using carbon derived from the raw gas, they are different from valuable substances derived from petroleum. 14 C, 13 The abundance ratio of carbon isotopes such as C (for example, δ 14 C, δ 13 The value of C) is different. Therefore, even if this valuable substance is converted and used as a product such as other compounds, it can be discriminated (traced) that it is derived from a valuable substance generated by an environmentally friendly method by the manufacturing system 100.

[0021] Examples of gas-assimilating bacteria include Butyribacterium methylotrophicum, Clostridium autoethanogenum, Clostridium carboxidivorans, Clostridium ljungdahlii, Clostridium ragsdalei, Moorella, and Carboxydothermus. Examples of algae include cyanobacteria, Chlorella, Botryococcus, Nannochloropsis, Haematococcus, Senedesmus, Stichococcus, Nannochloris, and Desmodesmus.

[0022] When using microorganisms such as gas-utilizing bacteria or algae, in valuable materials 14 C, 13 The abundance of carbon isotopes such as ¹¹C (e.g., δ¹¹C) 14 C, δ 13 The value of C can be made to deviate even more significantly from the value of petroleum-derived products. Therefore, even if the generated valuable material is converted into other compounds and used, it becomes easier to determine (trace) that it originates from the valuable material produced by the environmentally friendly manufacturing system 100.

[0023] The culture medium (culture solution) used when culturing microorganisms is not particularly limited, as long as it has an appropriate composition for the type of microorganism. When using Clostridium bacteria as gas-assimilating bacteria, for example, paragraphs 0097-0098 of U.S. Patent Application Publication No. 2017 / 260552 can be used as a reference for the culture medium. The culture tank 2 can be, for example, a culture reactor that agitates the culture medium with a stirring plate, a culture reactor that agitates the culture medium by circulating the culture medium itself, or a culture reactor that agitates the culture medium with a water flow associated with a bubble flow generated by the aeration of the supplied raw material gas.

[0024] Furthermore, the valuable substance generation section may be composed of a reactor containing a catalyst instead of the culture tank 2. In this case, examples of catalysts include ruthenium, rhodium, manganese, germanium, tantalum, zirconium, niobium, hafnium, lanthanum, cerium, aluminum, magnesium, copper, zinc, silicon, or oxides thereof. These substances may be used individually or in combination of two or more.

[0025] The manufacturing apparatus 1 includes a pre-processing unit (separation unit) 5 located in the middle of the gas line GL1 (i.e., between the gasification furnace 10 and the culture tank 2). This pre-processing unit (separation unit) 5 removes various impurities from the raw material gas containing carbon monoxide, carbon dioxide, and hydrogen, and generates a raw material gas (combined gas) with a higher concentration of carbon monoxide. Specifically, the pre-processing unit 5 includes, in order from the upstream side (gasifier 10 side), a dust removal device 54 and a PSA device 51.

[0026] The dust removal device 54 has the function of removing solid impurities. By installing this dust removal device 54, the amount of solid impurities (soot generated during combustion in the gasification furnace 10) brought into the PSA device 51 can be reduced. This reduces the frequency of maintenance of the PSA device 51. In addition, since the amount of soot contained in the raw material gas supplied to the valuable product generation section can be reduced, it becomes less likely to adversely affect microorganisms and catalysts, and the efficiency of valuable product generation can be improved.

[0027] This dust removal device 54 can be composed of, for example, a wet washing tower, a filter, and the like. A wet scrubbing tower is a type of scrubber used to remove contaminants (such as soot) contained in the raw gas. In a wet scrubbing tower, the removal process is carried out by bringing a cleaning solution into contact with the object to be removed (wet scrubbing method). One example of a wet scrubbing method is a cleaning method using a water curtain. Examples of cleaning solutions include water, acidic solutions, and alkaline solutions. Among these, water is preferred as the cleaning solution. The temperature of the cleaning solution is usually 40°C or lower, preferably 30°C or lower, more preferably 25°C or lower, and even more preferably 15°C or lower. Filters are used to remove fine particles smaller than the size of soot. These filters can be, for example, bag filters.

[0028] The PSA device 51 is a pressure swing adsorption type separator and has the function of separating a separation gas containing carbon dioxide from the raw material gas after it has passed through the dust removal device 54. The PSA device 51 includes, for example, a container, an adsorbent contained in the container, and a vacuum pump connected to the container. The adsorbent can consist of one or more porous materials such as zeolite, bentonite, sericite, perlite, coral reef rock, vermiculite, silica gel, molecular sieves, activated carbon, and MOF (metal-organic framework). Among these, activated carbon or zeolite is preferably used as the adsorbent. By setting the type of porous material and the size of the pores, the compounds that can be separated can be selected.

[0029] When separating two or more compounds in the PSA apparatus 51, multiple separators filled with porous materials of different types and pore sizes may be used, or a single separator filled with porous materials of different types and pore sizes may be used. The average particle size of the adsorbent is preferably 0.5 mm to 10 mm, more preferably 0.8 mm to 8 mm, and even more preferably 1 mm to 6 mm. In this case, the contact area of ​​the adsorbent with the raw material gas can be sufficiently large. The shape is not limited to spherical; for example, it may be cylindrical or the like. In this specification, average particle size means the average value of the particle sizes of any 200 particles in a single field of view observed with an electron microscope. In this context, "particle size" means the maximum distance between any two points on the contour line of the particle.

[0030] Furthermore, the BET specific surface area of ​​the adsorbent is 50 m². 2 / g or more 1200m 2 It is preferable that it be less than or equal to / g, and 100m 2 / g or more 1000m 2 It is more preferable that it be less than or equal to / g, and 200m 2 / g or more 800m 2 It is even more preferable that the amount is less than or equal to / g. In this case, the contact area of ​​the adsorbent with the raw material gas can be sufficiently large. In this specification, the BET specific surface area is a value measured using a BET specific surface area meter in accordance with the BET single-point method ("Method for measuring the specific surface area of ​​fine ceramic powder by gas adsorption BET method" as specified in JIS R 1626:1996). The average pore size of the adsorbent is preferably 0.5 Å to 200 Å, more preferably 2.5 Å to 175 Å, and even more preferably 5 Å to 150 Å. In this specification, the average pore diameter is a value measured by pore diameter distribution measurement using the mercury intrusion method with a mercury porosimeter.

[0031] A gas composition conversion unit 8 is connected to the PSA device 51 via the gas line GL2. The gas composition conversion unit 8 has the function of converting carbon dioxide in the separated gas into carbon monoxide and oxygen. Furthermore, an impurity removal section 7 is provided in the middle of the gas line GL2. The impurity removal section 7 has the function of removing impurities, including substances that adversely affect the conversion reaction of carbon dioxide to carbon monoxide and oxygen. Examples of the above substances include hydrogen sulfide and sulfur oxides (SO4). X Examples include sulfur-containing compounds such as carbonyl sulfide, hydrocarbon compounds such as acetylene and aromatic hydrocarbons (BTEX), chlorine, nitric oxide, hydrogen fluoride, and hydrogen cyanide. Among these, it is preferable that the above substances include at least one selected from the group consisting of sulfur-containing compounds and hydrocarbon compounds. These substances are thought to adhere to the surface of the components of the gas composition conversion unit 8 (e.g., electrodes, photocatalysts, etc.) described later, and to highly inhibit or suppress the above conversion reaction.

[0032] It is preferable that the impurity removal unit 7 is also composed of a PSA device. This PSA device comprises, for example, a second container, a second adsorbent contained in the second container, and a second vacuum pump connected to the second container. The second adsorbent can be made of a porous material similar to those mentioned above. Among these, activated carbon, zeolite, or MOF are preferably used as the second adsorbent. This is because they have particularly excellent adsorption capacity for sulfur-containing compounds and hydrocarbon compounds. By setting the type of porous material and the size of the pores, a specific substance can be selectively adsorbed.

[0033] The average particle size of the second adsorbent is preferably 0.5 mm or more and 10 mm or less, more preferably 0.8 mm or more and 8 mm or less, and even more preferably 1 mm or more and 6 mm or less. Furthermore, in the case of the adsorbent and the second adsorbent, if their shapes are elliptical or columnar, the average value of the length of the major axis and the length of the minor axis is defined as the particle size of the adsorbent, and the average value of this particle size is defined as the average particle size of the adsorbent. Furthermore, the BET specific surface area of ​​the second adsorbent is 100 m². 2 / g or more 2500m 2It is preferable that it be less than / g, and 200m 2 / g or more 2000m 2 It is more preferable that it be less than / g, and 300m 2 / g or more 1500m 2 It is even more preferable that the amount be less than or equal to / g. The average pore size of the second adsorbent is preferably 1 Å or more and 300 Å or less, more preferably 3 Å or more and 250 Å or less, and even more preferably 5 Å or more and 200 Å or less. By appropriately setting these numerical ranges, the contact area of ​​the second adsorbent with the raw material gas can be sufficiently increased.

[0034] A moisture removal device (water vapor removal device) may be provided between the dust removal device 54 and the PSA device 51. The moisture removal device comprises a container and a moisture adsorbent contained within the container. The moisture adsorbent can be composed of one or more materials, such as alumina, zeolite, or silica gel. Removing moisture (water vapor) upstream of the PSA device 51 and impurity removal unit 7 makes it easier to improve the processing efficiency of the raw material gas in the PSA device 51 and impurity removal unit 7. Furthermore, since moisture is difficult to remove once it is adsorbed onto a moisture adsorbent, using a relatively inexpensive moisture adsorbent can reduce the manufacturing cost of valuable materials.

[0035] Furthermore, the moisture removal device is not limited to being a separate device from the PSA device 51; for example, it may be integrated with the PSA device 51. Furthermore, it is preferable that the moisture removal device has an adsorption selectivity ratio of 2 or higher for water vapor to carbon dioxide. In this case, moisture can be selectively (preferentially) removed, and thus the gas density flowing into the area where the adsorbent is placed (contained) in the PSA device 51 and the impurity removal section 7 can be increased. This is preferable because it is expected to extend the lifespan of the adsorbent for hydrogen sulfide and carbon dioxide removal. Note that the adsorption selectivity ratio refers to the ratio of the adsorption energy of water vapor to carbon dioxide relative to the adsorbent. Furthermore, the temperature of the moisture removal device is preferably 20°C or lower. By reducing the temperature inside the moisture removal device in this way, the amount of saturated water vapor can be reduced, thereby preventing or suppressing variations in gas composition even within a certain humidity range.

[0036] The gas composition conversion unit 8 includes a reactor 81 and an oxygen scavenger 82 contained within the reactor 81. Furthermore, the conversion of carbon dioxide to carbon monoxide and oxygen is preferably carried out by at least one of carbon dioxide plasma generation and a photocatalytic reaction, particularly from the viewpoint of increasing conversion efficiency. When the process is carried out by plasma generation of carbon dioxide, a voltage application mechanism for applying a high-frequency voltage is attached to the reactor 81. On the other hand, when the process is carried out by a photocatalytic reaction, a photocatalyst is housed in the reactor 81, and the reactor 81 may be equipped with a light irradiation mechanism for irradiating the photocatalyst with light of a predetermined wavelength (for example, ultraviolet light, etc.), or the reactor 81 may be configured to allow light of a predetermined wavelength to pass through, and light such as sunlight that passes through may be utilized, so as not to require external energy.

[0037] At this point, the following conversion reaction proceeds within reactor 81.

number

[0038] In the case of plasma formation, the flow rate of the separated gas to the reactor (plasma reactor) 81 is preferably 170 mol / min or more and 3500 mol / min or less, more preferably 200 mol / min or more and 3000 mol / min or less, and even more preferably 250 mol / min or more and 2500 mol / min or less. By setting the flow rate of the separated gas in this way to a relatively low level, the above conversion reaction can be carried out sufficiently. Furthermore, the applied voltage to the separated gas is preferably 0.1kV to 80kV, more preferably 0.5kV to 70kV, and even more preferably 1kV to 60kV. In this case, the above-mentioned conversion reaction is more likely to occur.

[0039] On the other hand, in the case of photocatalytic reactions, it is preferable that the photocatalyst used is at least one selected from the group consisting of metal oxides, metal salts, metal nitrides, and metal sulfides. Many of these substances have relatively narrow band gaps, making them easy to use as photocatalysts. Examples of metal oxides include titanium oxide, zirconium oxide, niobium oxide, tungsten oxide, and iron oxide. Examples of metal salts include tantalates, niobates, and vanadates. Examples of metal nitrides include gallium nitride. Examples of metal sulfides include cadmium sulfide and zinc sulfide. Furthermore, photocatalysts can also utilize complexes containing copper, manganese, and other elements.

[0040] The gas composition conversion unit 8 is connected to gas line GL1 via gas line GL3. This allows the raw material gas (raw material gas with a higher carbon monoxide concentration) that has passed through the PSA device 51 and been separated from to be combined with the converted gas (converted gas with a higher carbon monoxide concentration) from which oxygen has been removed. A pump P is installed in the middle of the gas line GL3. By operating pump P, the pressure inside reactor 81 can be reduced, and the conversion gas after passing through pump P can be pressurized. By reducing the pressure inside reactor 81, the conversion reaction represented by equation (1) above is shifted to the right, making it easier to convert carbon dioxide into carbon monoxide and oxygen. On the other hand, by pressurizing the conversion gas after passing through pump P, it is possible to effectively prevent or suppress the flow of raw material gas passing through gas line GL1 into gas line GL3.

[0041] Furthermore, the pre-processing unit 5 may include, in addition to the PSA apparatus 51 and the impurity removal unit 7, for example, a deacetylene apparatus, a TSA apparatus, a PTSA apparatus, etc. These can be used individually or in any combination, and their arrangement order is also arbitrary. Furthermore, they may be installed in the middle of gas line GL2 or in the middle of gas line GL3. The acetylene removal apparatus is used to remove acetylene and can consist of a reactor filled with particles of a precious metal such as palladium (Pd) or platinum (Pt) as an acetylene removal catalyst. Furthermore, removing acetylene prior to deoxygenation has the advantage of effectively preventing or reducing the adverse effects of acetylene on the oxygen scavenger 82 (oxygen removal catalyst).

[0042] The TSA device is a temperature swing adsorption type separator used, for example, to remove aromatic compounds other than BTEX, nitric oxide, etc. The PTSA apparatus is a pressure and temperature swing adsorption type separator, and is used, for example, to remove components that are removed by the PSA apparatus 51, impurity removal unit 7, and TSA apparatus all at once. The type of adsorbent and constituent materials used in the TSA and PTSA devices can be the same as those described for the PSA device 51 and the impurity removal unit 7. Furthermore, the oxygen absorber 82 may be placed in the middle of the gas line GL3 as an oxygen absorber filled in a container, either in place of or in addition to the reactor 81. This oxygen absorber may be configured to remove other unwanted elements or molecules, and these unwanted elements or molecules may be removed using a device (means) provided separately from the oxygen absorber. Examples of such unwanted elements or molecules include nitrogen oxides that can be generated from nitrogen, etc., by plasma generation. Nitrogen oxides include, for example, nitric oxide and nitrogen dioxide. If nitrogen oxides are present in the conversion gas, they may adversely affect metal catalysts, etc., when catalytic reactions are carried out downstream. Also, if nitrogen oxides are discharged into the surrounding environment, they may adversely affect human health or the surrounding environment, so from this viewpoint as well, it is preferable that they be removed from the conversion gas. It should be noted that nitrogen oxides do not need to be completely removed from the conversion gas. The nitrogen oxide content in the conversion gas after nitrogen oxides have been removed is preferably, for example, that the nitric oxide content is about 1000 ppm or less. In this case, adverse effects on metal catalysts, etc., are less likely to occur in the catalytic reaction described above.

[0043] The combined gas, which is produced by combining the raw material gas and the converted gas processed in the pre-processing unit 5, is supplied to the culture tank 2. In this combined gas, various impurities are sufficiently removed, thus reducing variations in its composition. This makes it easier to predict the amount of valuable substances produced in the culture tank (valuable substance production unit) 2, and therefore easier to operate the valuable substance production system 100 stably. The concentration of carbon monoxide in the combined gas supplied to the culture tank 2 is preferably 10% by volume or more and 90% by volume or less, more preferably 15% by volume or more and 70% by volume or less, and even more preferably 20% by volume or more and 45% by volume or less.

[0044] The concentration of carbon dioxide in the combined gas supplied to the culture tank 2 is preferably 0.1% by volume or more and 30% by volume or less, more preferably 0.3% by volume or more and 25% by volume or less, even more preferably 0.5% by volume or more and 20% by volume or less, particularly preferably 0.8% by volume or more and 15% by volume or less, and most preferably 1% by volume or more and 10% by volume or less. Furthermore, the concentration of hydrogen in the combined gas supplied to the culture tank 2 is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, and particularly preferably 0.1% by mass or more and 5% by mass or less. By reducing the concentration of hydrogen in the combined gas, variations in the composition of the combined gas over time can be sufficiently suppressed.

[0045] The nitrogen concentration in the combined gas supplied to the culture tank 2 is preferably 30% by volume or less, more preferably 1% to 25% by volume, and even more preferably 5% to 20% by volume. Furthermore, the lower the oxygen concentration in the combined gas supplied to culture tank 2, the better. Therefore, the oxygen concentration may be below the detection limit of a sensor such as a digital oxygen concentration meter. In this case, the partial pressure of oxygen in the combined gas can be reduced, and the partial pressure of carbon monoxide can be increased accordingly. On the other hand, reducing the oxygen concentration to 0 (zero) would be too costly and therefore not practical. Specific examples of usable digital oxygen concentration meters include the "XP-3180E" and "EA733D-2," both manufactured by Shin-Cosmos Electric Co., Ltd.

[0046] Because this combined gas is supplied to culture tank 2, hydrogen and oxygen are less likely to reduce the activity of microorganisms (gas-utilizing bacteria). In other words, since hydrogen and oxygen at concentrations suitable for use by microorganisms can be supplied, the microorganisms can function actively. Furthermore, in the combined gas, carbon dioxide is mainly separated (removed) in the PSA device 51, and in the gas composition conversion unit 8, carbon dioxide is converted into carbon monoxide and oxygen, and oxygen is removed, resulting in a sufficiently high concentration of carbon monoxide. Therefore, valuable materials can be produced more efficiently in the culture tank 2. Furthermore, since the overall volume of the combined gas is reduced, the size of the piping, pumps, containers, etc., located in the pre-processing unit 5 and / or downstream thereof can also be reduced.

[0047] In culture tank 2, valuable substances, specifically a liquid containing valuable substances, are generated from the combined gas using microorganisms (gas-utilizing bacteria or algae). A purification device 6 is connected to culture tank 2 via liquid line LL. This purification device 6 is a device that purifies valuable substances (organic substances) from a liquid containing valuable substances. Examples of such purification apparatus 6 include distillation apparatus, permeable vaporization membrane apparatus, zeolite dehydration membrane apparatus, organic membrane apparatus, apparatus for removing low-boiling-point substances with a boiling point lower than that of the valuable substance, apparatus for removing high-boiling-point substances with a boiling point higher than that of the valuable substance, and apparatus for removing ion exchange membrane. These apparatuses may be used individually or in combination of two or more types.

[0048] When using a distillation apparatus, for example, the temperature inside the distillation apparatus during the distillation of ethanol, a valuable substance, is not particularly limited, but is preferably 100°C or lower, and more preferably 70°C to 95°C. By setting the temperature to this level, the separation of the required valuable substance from other components, i.e., the distillation (purification) of the valuable substance, can be carried out more reliably. The pressure inside the distillation apparatus during the distillation of valuable materials may be atmospheric pressure, but it is preferable to be below atmospheric pressure (reduced pressure distillation), and more preferably between 60 kPaA and 95 kPaA. Setting the pressure to this level improves the separation efficiency of valuable materials and, consequently, the yield of valuable materials.

[0049] Furthermore, for example, the temperature inside the distillation apparatus during the distillation of acetic acid, which is a valuable substance, is not particularly limited, but is preferably 95°C or higher, and more preferably 100°C to 150°C. The pressure inside the distillation apparatus during the distillation of valuable substances may be atmospheric pressure, but it is preferably below atmospheric pressure (reduced pressure distillation), and more preferably between 60 kPaA and 95 kPaA. Setting the pressure to this level improves the separation efficiency of valuable substances and, consequently, the yield of valuable substances. In addition, azeotropes and the like may be added to the liquid containing valuable substances. The yield of valuable substances (concentration of valuable substances in the purified product) is preferably 90% by mass or more, more preferably 99% by mass or more, and even more preferably 99.5% by mass or more.

[0050] Valuable substances obtained in this way include, for example, monools such as methanol and ethanol, diols such as 2,3-butanediol, acetic acid, lactic acid, isoprene, butadiene, and the like, preferably monools or diols having 1 to 4 carbon atoms, and more preferably ethanol. Such valuable substances can be used, for example, as raw materials for resin materials, rubber materials, etc., and can also be used as various solvents, disinfectants, or fuels. Furthermore, high-concentration ethanol can be used as fuel ethanol mixed with gasoline, etc., and can also be used as a raw material for cosmetics, beverages, chemical substances, fuels (jet fuel), etc., and as an additive for food, etc., making it extremely versatile.

[0051] Furthermore, a hydrogen separation device may be installed at least one point along gas line GL2 and gas line GL3. Preferably, this hydrogen separation device can consist of a separator containing a separation membrane that selectively permeates and separates hydrogen. Examples of materials for such a separation membrane include metal materials, ceramic materials, and resin materials. Examples of metallic materials include Pd-Cu alloys, Pd-Ag alloys, vanadium alloys, and amorphous alloys such as La-Ni-Mg alloys. Examples of ceramic materials include titanium nitride, zeolite, silica (glass), alumina, and composite materials containing one or more of these (e.g., alumina-carbon materials). Examples of resin materials include polyamide, polyimide, and polysulfone.

[0052] The separation membrane is preferably made of a porous material having continuous pores (pores that penetrate the cylindrical wall) where adjacent pores communicate with each other. With a separation membrane of this configuration, hydrogen separation can be performed more smoothly and reliably. The porosity of the separation membrane is not particularly limited, but is preferably 10% to 90%, and more preferably 20% to 60%. This prevents an extreme decrease in the mechanical strength of the separation membrane while maintaining a sufficiently high hydrogen permeability. The shape of the separation membrane is not particularly limited and can be cylindrical, square, hexagonal, or other rectangular shapes. The average pore size of the separation membrane is preferably 500 pm or less, and more preferably 300 pm to 400 pm. This allows for a further improvement in hydrogen separation efficiency.

[0053] Next, the method of using the manufacturing system 100 of this embodiment (method of manufacturing valuable materials) will be described. [1] First, raw material gas containing carbon monoxide, carbon dioxide and hydrogen is produced (prepared) by burning a gasification raw material containing organic matter (for example, waste) in a gasification furnace 10 (first step). [2] Next, the raw material gas discharged from the gasification furnace 10 is supplied to the pre-treatment unit 5. First, the dust removal device 54 removes solid impurities (for example, soot, fine particles smaller than soot, etc.) from the raw gas. [3] Next, the PSA unit 51 separates and recovers the carbon dioxide-containing separation gas from the raw material gas that has passed through the dust removal unit 54 (second step). In other words, this step [3] (second step) is carried out by the PSA unit 51.

[0054] [4] Next, the impurity removal unit 7 removes impurities from the separated gas (third step). Here, the impurities include substances that adversely affect (inhibit or suppress) the conversion reaction of carbon dioxide to carbon monoxide and oxygen in the next step [5]. By removing such impurities, the conversion reaction in the next step [5] proceeds smoothly. [5] Next, in the gas composition conversion unit 8, carbon dioxide in the separated gas from which impurities have been removed is converted into carbon monoxide and oxygen to generate a conversion gas, while oxygen is removed from the conversion gas (fourth step). As described above, this step [5] (fourth step) is carried out smoothly by at least one of the plasma formation of carbon dioxide and the photocatalytic reaction. At this time, it is preferable to reduce the pressure inside the reactor 81 by the action of the pump P. That is, it is preferable to carry out the fourth step under reduced pressure. This makes it possible to increase the efficiency of the conversion of carbon dioxide to carbon monoxide and oxygen.

[0055] At this time, unreacted carbon dioxide may be returned to the gas composition conversion unit 8. In this case, it is preferable to mix carbon dioxide derived from the raw material gas or carbon dioxide derived from a gas with a higher carbon dioxide concentration than the raw material gas. If excess carbon dioxide is produced, methanol may be synthesized using, for example, a copper-zinc catalyst. By synthesizing a liquid substance such as methanol in this way, it can be used as a carbon dioxide source when needed, and it can also be burned to produce synthesis gas. Note that the above substance is not limited to alcohols such as methanol, but may also be carboxylic acids such as formic acid, or hydrocarbons containing alkanes such as methane.

[0056] Preferably, the substance converted from carbon dioxide is burned to produce a carbon dioxide-containing gas when the gasification furnace 10 is shut down, and a portion of the generated carbon dioxide-containing gas is converted to carbon monoxide and introduced into the valuable substance production section (culture tank 2, etc.). Furthermore, when the gasifier 10 is shut down, it is preferable that the generation of carbon dioxide-containing gas is controlled so that the total amount of gas remains within a certain range, for example, based on a decrease in the amount of waste input and / or a decrease in the gas flow rate. Such control can be achieved, for example, by predicting the time from the decrease in the amount of waste input until a decrease in the amount of gas occurs, and generating carbon monoxide as described above at the timing when a decrease in the amount of gas is predicted to occur.

[0057] Here, the carbon dioxide derived from a gas with a higher carbon dioxide concentration than the source gas as described above can be any gas that has a higher carbon dioxide concentration than the carbon dioxide concentration at the time the source gas was generated, such as the gas obtained after separating carbon monoxide from unreacted carbon dioxide. However, it is preferable that the carbon dioxide concentration of such a gas be between 1.1 and 3 times the carbon dioxide concentration at the time the source gas was generated. The gas that satisfies the above carbon dioxide concentration range may be, for example, a carbon dioxide-containing gas generated during wastewater treatment, a carbon dioxide-containing gas discharged from the culture tank 2, or a carbon dioxide-containing gas produced from formic acid, etc.

[0058] Furthermore, in the pre-treatment step 5, impurities such as acetylene, aromatic compounds other than BTEX, and nitric oxide may be removed from the raw material gas. In other words, the method for producing valuable materials may include a step to remove these impurities. If such impurities are present in the raw material gas, there is a concern that energy efficiency may decrease because reaction (conversion) energy may be consumed when the impurities are converted into other substances. Furthermore, if impurities are present in the raw material gas, some of the components generated by plasma generation that are not introduced into the culture tank may contain components that could be harmful to humans or the environment. Therefore, the amount of such components discharged must be controlled, which may increase removal costs. For these reasons, it is preferable to remove impurities such as acetylene, aromatic compounds other than BTEX, and nitric oxide from the raw material gas.

[0059] [6] Next, the separated raw material gas passing through gas line GL1 and the converted gas from which oxygen has been removed passing through gas line GL3 are combined to produce a combined gas (fifth step). At this time, it is preferable to pressurize the converted gas by the action of pump P. That is, in this step [6] (fifth step), pressure control is performed so that the pressure of the converted gas is higher than the pressure of the raw material gas. This prevents the raw material gas passing through gas line GL1 from flowing into gas line GL3, so that the combined gas can be reliably supplied to the culture tank 2. Preferably, this pressure control is performed by measuring the gas composition (particularly the ratio of hydrogen concentration to carbon monoxide concentration) around the PSA device 51, and based on the measurement results, ensuring that the carbon monoxide concentration / hydrogen concentration ratio in the synthesis gas is within a predetermined range, and then introducing the pressure-controlled synthesis gas into the culture tank 2. Furthermore, a measuring unit capable of measuring the gas composition may be provided upstream of the pressure control unit for the converted gas (pump P in this embodiment). In addition, the elapsed time from the outlet of the PSA device 51 to the confluence point (connection point) of gas line GL1 and gas line GL3 may be predicted, and the pressure control unit may be controlled based on the prediction result.

[0060] [7] Subsequently, in culture tank 2, a valuable substance, specifically a valuable substance-containing liquid, is produced from the combined gas (sixth step). In other words, in this step [7] (sixth step), the production of the valuable substance is carried out using microorganisms. In this embodiment, the combined gas is primarily separated (removed) of carbon dioxide in the PSA device 51, and then converted to carbon monoxide and oxygen in the gas composition conversion unit 8, while oxygen is removed, resulting in a sufficiently high concentration of carbon monoxide. Furthermore, the combined gas is less prone to variations in gas composition. Therefore, the amount of valuable substances produced can be predicted without separately checking the composition of the combined gas. The concentrations of each gas component contained in the combined gas are preferably adjusted to the above range. When a series of steps in the method for producing a valuable product are considered as one cycle and multiple cycles are repeated, it is preferable that the concentrations are adjusted to the above range in each cycle.

[0061] Here, the temperature at which the valuable substance-containing liquid is produced in the culture tank (valuable substance production section) 2 is preferably 25°C or higher and 50°C or lower, more preferably 30°C or higher and 45°C or lower, and even more preferably 35°C or higher and 40°C or lower. [8] Next, the valuable substance-containing liquid produced in the culture tank 2 is supplied to the purification device 6 via the liquid line LL. In the purification device 6, the valuable substance contained in the valuable substance-containing liquid is purified, and a purified product containing the valuable substance at a high concentration is obtained. In the above-described method for manufacturing valuable materials, the pretreatment step 5 does not involve processing in the liquid phase, but rather processing in the gas phase. This means that there is no change in state between the liquid phase and the gas phase, resulting in superior processing efficiency.

[0062] If heating is required for the conversion reaction in step [5] above, this reaction may be carried out using the heat generated during the combustion in step [1] above. In this case, the heat generated by combustion can be effectively utilized without being wasted. For example, gas line GL2 can be placed close to gas line GL1 near the outlet of gasification furnace 10, and heat exchange can be performed between the high-temperature raw material gas discharged from gasification furnace 10 and the gas flowing through gas line GL2. In this case, the reaction in step [5] is preferably carried out at a temperature of 50°C or higher, more preferably at a temperature of 70°C or higher, and even more preferably at a temperature of 90°C to 150°C.

[0063] Furthermore, the manufacturing system 100 described above may generate predictive information based on the composition of the raw material gas produced in the gasifier 10 and a pre-set trained model. The predictive information is information regarding the amount of valuable material produced. Here, the trained model is a model that has been trained to output predictive information based on the composition of the raw material gas produced in the gasifier 10. The trained model may be constructed using learning methods such as supervised learning, unsupervised learning, or self-supervised learning. Furthermore, the trained model may include general-purpose natural language processing models, such as Large Language Models (LLMs), which have been trained on a vast amount of data, as an artificial intelligence.

[0064] The functions of the manufacturing system 100 described above are performed by the computer and processor provided within the manufacturing system 100. Furthermore, the manufacturing system 100 may be connected to an external computer via the Internet. In this case, the manufacturing system 100 may send data to the external computer to generate a trained model or output predictive information from the trained model. Furthermore, they may be provided in the following embodiments.

[0065] (1) A method for producing a valuable substance, comprising: a first step of preparing a raw material gas containing carbon monoxide, carbon dioxide and hydrogen; a second step of separating and recovering a separated gas containing carbon dioxide from the raw material gas; a third step of removing impurities from the separated gas; a fourth step of converting the carbon dioxide in the separated gas from which the impurities have been removed into carbon monoxide and oxygen to produce a converted gas, while removing the oxygen from the converted gas; a fifth step of combining the raw material gas from which the separated gas has been separated and the converted gas from which the oxygen has been removed to produce a combined gas; and a sixth step of producing the valuable substance from the combined gas, wherein the impurities include substances that adversely affect the conversion reaction of carbon dioxide into carbon monoxide and oxygen.

[0066] (2) A method for producing a valuable substance as described in (1) above, wherein the substance comprises at least one selected from the group consisting of sulfur-containing compounds and hydrocarbon compounds.

[0067] (3) A method for producing a valuable substance as described in (1) or (2) above, wherein the fourth step is carried out by at least one of the plasma generation of carbon dioxide and the photocatalytic reaction.

[0068] (4) A method for producing a valuable substance as described in (3) above, wherein the flow rate of the separated gas to the plasma reactor is 170 mol / min or more and 3500 mol / min or less.

[0069] (5) A method for producing a valuable substance as described in (3) or (4) above, wherein the voltage applied to the separation gas is 0.1kV or more and 80kV or less.

[0070] (6) A method for producing a valuable substance according to any one of (3) to (5) above, wherein the photocatalyst used in the photocatalytic reaction is at least one selected from the group consisting of metal oxides, metal salts, metal nitrides, and metal sulfides.

[0071] (7) A method for producing a valuable substance according to any one of (3) to (6) above, wherein the fourth step is carried out under reduced pressure.

[0072] (8) A method for producing a valuable substance according to any one of (1) to (3) above, wherein in the fifth step, pressure control is performed so that the pressure of the converted gas is higher than the pressure of the raw material gas.

[0073] (9) A method for manufacturing a valuable substance according to any one of (1) to (8) above, wherein the second step is performed by a PSA device.

[0074] (10) A method for producing a valuable substance according to any one of (1) to (9) above, wherein in the sixth step, the production of the valuable substance is carried out using microorganisms. Of course, this is not always the case.

[0075] As previously described, various embodiments of the present invention have been explained, but these are merely examples and do not limit the scope of the invention in any way. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. For example, the method for manufacturing a valuable product may have any additional steps compared to the above embodiment, may be replaced by any steps that perform a similar function, and some steps may be omitted. [Explanation of symbols]

[0076] 100: Manufacturing systems for valuable goods 10: Gasification furnace 1: Equipment for manufacturing valuable materials 2:Culture tank 5: Pre-processing section 51:PSA device 54: Dust removal equipment 6: Purification equipment 7: Impurity removal section 8: Gas composition conversion unit 81: Reactor 82: Oxygen absorber GL1: Gas line GL2: Gas line GL3: Gas line LL: Liquid line P: Pump

Claims

1. A method for manufacturing valuable materials, The first step involves preparing a raw material gas containing carbon monoxide, carbon dioxide, and hydrogen, A second step of separating and recovering the separated gas containing carbon dioxide from the raw material gas, A third step of removing impurities from the separated gas, A fourth step involves converting the carbon dioxide in the separated gas from which the impurities have been removed into carbon monoxide and oxygen to generate a converted gas, while simultaneously removing the oxygen from the converted gas. A fifth step involves combining the separated raw material gas and the converted gas from which the oxygen has been removed to produce a combined gas. The system comprises a sixth step of generating the valuable substance from the combined gas, A method for producing a valuable product, wherein the impurities include substances that adversely affect the conversion reaction of carbon dioxide to carbon monoxide and oxygen.

2. In the method for producing a valuable substance according to claim 1, A method for producing a valuable substance, wherein the substance comprises at least one selected from the group consisting of sulfur-containing compounds and hydrocarbon compounds.

3. In the method for producing a valuable substance according to claim 1, The fourth step is a method for producing a valuable substance, which is carried out by at least one of the plasma generation of carbon dioxide and a photocatalytic reaction.

4. In the method for manufacturing a valuable substance according to claim 3, A method for producing a valuable substance, wherein the flow rate of the separated gas to the plasma reactor is 170 mol / min or more and 3500 mol / min or less.

5. In the method for manufacturing a valuable substance according to claim 3, A method for manufacturing valuable materials, wherein the voltage applied to the separated gas is 0.1 kV or more and 80 kV or less.

6. In the method for manufacturing a valuable substance according to claim 3, A method for producing valuable substances, wherein the photocatalyst used in the photocatalytic reaction is at least one selected from the group consisting of metal oxides, metal salts, metal nitrides, and metal sulfides.

7. In the method for manufacturing a valuable substance according to claim 3, The fourth step is a method for producing a valuable substance, carried out under reduced pressure.

8. In the method for producing a valuable substance according to claim 1, A method for manufacturing a valuable product, wherein in the fifth step, pressure control is performed so that the pressure of the conversion gas becomes higher than the pressure of the raw material gas.

9. In the method for producing a valuable substance according to claim 1, The second step is a method for manufacturing a valuable substance, performed using a PSA apparatus.

10. In the method for producing a valuable substance according to claim 1, A method for producing a valuable substance, wherein in the sixth step, the production of the valuable substance is carried out using microorganisms.

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