System for producing organic substance, device for producing organic substance, and method for producing organic substance

Abstract

[Problem] To provide: a system for producing an organic substance, the system being capable of efficiently removing impurities from a starting material gas by reducing thermal energy used in a pretreatment; and others. [Solution] A system for producing an organic substance is provided according to one aspect of the present invention. This production system comprises: a gas generation unit that generates a starting material gas containing at least carbon monoxide, carbon dioxide, and a monocyclic aromatic compound; a first separation unit having a first adsorbent capable of adsorbing at least carbon dioxide in the starting material gas and a first storage part in which the first adsorbent is disposed, wherein carbon dioxide can be desorbed and separated from the first adsorbent by decompressing the inside of the first storage part; a second separation unit having a second adsorbent capable of adsorbing at least the monocyclic aromatic compound in the starting material gas and a second storage part in which the second adsorbent is disposed, wherein the monocyclic aromatic compound can be desorbed and separated from the second adsorbent by decompressing the inside of the second storage part; a decompression mechanism capable of decompressing the inside of the first storage part and the inside of the second storage part; and a culture tank to which the starting material gas from which carbon dioxide and the monocyclic aromatic compound have been separated is supplied to generate an organic substance from carbon monoxide contained in the supplied starting material gas by the action of a gas-assimilating bacterium.

Description

Organic substance manufacturing system, organic substance manufacturing device, and organic substance manufacturing method

[0001] The present invention relates to a system for producing an organic substance, an apparatus for producing an organic substance, and a method for producing an organic substance.

[0002] In recent years, global environmental problems have arisen, such as concerns about the depletion of fossil fuel resources and the increase in atmospheric carbon dioxide due to the mass consumption of oils and alcohols produced from petroleum. To address these problems, methods for producing organic substances using raw materials other than petroleum, such as the production of bioethanol by sugar fermentation from edible raw materials such as corn, have attracted attention.

[0003] Such sugar fermentation methods using edible raw materials may lead to a rise in food prices because limited agricultural land is used for non-food production. Therefore, methods for producing organic substances, which have traditionally been produced from petroleum, using non-edible raw materials that would otherwise be discarded are being considered. For example, Patent Document 1 discloses a method for producing organic substances by microbial fermentation of synthesis gas containing at least carbon monoxide. Patent Document 1 also discloses pretreatment of synthesis gas to remove impurities contained in the synthesis gas prior to microbial fermentation.

[0004] Re-table 2019 / 188730 publication

[0005] However, according to the investigations of the present inventors, when a temperature swing adsorption separator (TSA) is used in the pretreatment, there is a problem that a large amount of thermal energy is required. In view of the above circumstances, the present invention provides a system for producing an organic substance, etc., which can reduce the thermal energy used in the pretreatment and efficiently remove impurities from a raw material gas.

[0006] According to one aspect of the present invention, there is provided a system for producing an organic substance, comprising: a gas generation unit that produces a feed gas containing at least carbon monoxide, carbon dioxide, and monocyclic aromatic compounds; a first separation unit that has a first adsorbent capable of adsorbing at least carbon dioxide in the feed gas and a first container in which the first adsorbent is disposed, and that is capable of separating and separating carbon dioxide from the first adsorbent by reducing the pressure inside the first container; a second separation unit that has a second adsorbent capable of adsorbing at least the monocyclic aromatic compounds in the feed gas and a second container in which the second adsorbent is disposed, and that is capable of separating and separating the monocyclic aromatic compounds from the second adsorbent by reducing the pressure inside the second container; a pressure reduction mechanism that is capable of reducing the pressure inside the first container and the second container; and a culture tank that supplies the feed gas from which carbon dioxide and the monocyclic aromatic compounds have been separated, and that produces organic substances from the carbon monoxide contained in the supplied feed gas by the action of gas-assimilating bacteria.

[0007] According to this aspect, impurities can be efficiently removed from the source gas while reducing the amount of thermal energy used.

[0008] FIG. 1 is a schematic diagram showing the configuration of an organic substance production system according to a first embodiment. FIG. 2 is a schematic diagram showing the configuration of a separation device in the organic substance production system according to the first embodiment. FIG. 3 is a schematic diagram showing the configuration of an organic substance production system according to a second embodiment. FIG. 4 is a schematic diagram showing the configuration of an organic substance production system according to a third embodiment. FIG. 5 is a schematic diagram showing the configuration of an organic substance production system according to a fourth embodiment. FIG. 6 is a schematic diagram showing the configuration of a separation device in the organic substance production system according to the fourth embodiment.

[0009] Hereinafter, an organic substance production system, an organic substance production apparatus, and an organic substance production method will be described in detail based on preferred embodiments shown in the accompanying drawings. <First Embodiment> First, an organic substance production system according to the first embodiment will be described. Fig. 1 is a schematic diagram showing the configuration of the organic substance production system according to the first embodiment. Fig. 2 is a schematic diagram showing the configuration of a separation device in the organic substance production system according to the first embodiment.

[0010] The organic substance production system 100 (hereinafter also simply referred to as "production system 100") shown in FIG. 1 includes a gasifier (gas generation unit) 10 and an organic substance production apparatus 1 (hereinafter also simply referred to as "production apparatus 1") connected to the gasifier 10. That is, the organic substance production apparatus 1 is connected to the gasifier (gas generation unit) 10 when used. In this specification, the upstream side with respect to the flow direction of the raw material gas and liquid will also be simply referred to as the "upstream side", and the downstream side will also be simply referred to as the "downstream side". In this embodiment, the gasifier 10 can be, for example, a combustion furnace, a blast furnace, a converter, an electric furnace, a shaft furnace, etc. In addition to the gasifier 10, the gas generation unit can also be a CO2 generator of at least one facility selected from a paper mill, a cement factory, a thermal power plant, an oil refinery, an ethylene cracker, a refinery, and a chemical plant. ｘ It may also be an emission source.

[0011] In each furnace, exhaust gas (raw material gas) containing at least carbon monoxide, carbon dioxide, and monocyclic aromatic compounds is generated (produced) during combustion, melting, refining, etc. of the contents. In the case of a combustion furnace (incinerator) at a waste incineration plant, examples of the contents (waste) include plastic waste, food waste, municipal solid waste (MSW), industrial waste, discarded tires, biomass waste, household waste (futons, paper), building materials, etc. Note that these wastes may contain one type alone or two or more types.

[0012] Exhaust gas typically contains, in addition to carbon monoxide, carbon dioxide, and monocyclic aromatic compounds, other gas components such as nitrogen, hydrogen, oxygen, water vapor, and methane. Exhaust gas may further contain other components such as soot, tar, nitrogen compounds, sulfur compounds, phosphorus compounds, halogen compounds, cyanide compounds, and polycyclic aromatic compounds. Exhaust gas may be generated as a gas containing 10% by volume or more of carbon monoxide by performing a heat treatment (commonly known as gasification) to incompletely combust the contents (carbon source) (i.e., partially oxidizing the carbon source). Using exhaust gas allows for the effective use of carbon dioxide, which has traditionally been emitted into the atmosphere, and reduces the burden on the environment. Among these, exhaust gas generated in a combustion furnace or a smelter is preferred from the perspective of carbon circulation.

[0013] A production apparatus 1 is connected to the gasifier 10. The production apparatus 1 has a culture tank 2, a purification device 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 device 6. In the culture tank 2, organic substances are produced from the supplied exhaust gas (raw material gas) by the action of gas-assimilating bacteria (microbial fermentation). Specifically, an organic substance-containing liquid containing organic substances is obtained in the culture tank 2. Gas-assimilating bacteria include both eubacteria and archaea.

[0014] Examples of true bacteria include bacteria of the genus Clostridium, Moorella, Acetobacterium, Carboxydocella, Rhodopseudomonas, Eubacterium, Butyribacterium, Oligotropha, Bradyrhizobium, and the aerobic hydrogen-oxidizing bacteria Larsotonia.

[0015] On the other hand, examples of archaea include bacteria of the genus Methanobacterium, bacteria of the genus Methanobrevibacter, bacteria of the genus Methanococcus, bacteria of the genus Methanosarcina, bacteria of the genus Methanosphaera, bacteria of the genus Methanothermobacter, bacteria of the genus Methanothrix (M Examples of bacteria that can cause this include bacteria of the genus Ethanothrix, bacteria of the genus Methanoculus, bacteria of the genus Methanofollis, bacteria of the genus Methanogenium, bacteria of the genus Methanospirillium, bacteria of the genus Methanosaeta, bacteria of the genus Thermococcus, bacteria of the genus Thermophilum, bacteria of the genus Arcaheoglobus, and the like.

[0016] Among the gas-utilizing bacteria described above, bacteria with a high ability to produce the target organic substance are selected and used. Examples of gas-utilizing bacteria with a high ability to produce ethanol include Clostridium autoethanogenum, Clostridium ljungdahlii, Clostridium aceticum, Clostridium carboxydivorans, Moorella thermoacetica, and Acetobacterium woodii.

[0017] The medium (culture solution) used when culturing gas-assimilating bacteria is not particularly limited as long as it has an appropriate composition depending on the type of bacteria. For example, when Clostridium bacteria are used as the gas-assimilating bacteria, reference can be made to paragraph

[0091] of International Publication No. 2017 / 117309 and paragraphs

[0097] to

[0098] of U.S. Patent Application Publication No. 2017 / 260552 for the medium. For example, the culture vessel 2 can be a culture reactor that stirs the culture solution with a stirring plate, a culture reactor that stirs the culture solution by circulating the culture solution itself, or a culture reactor that stirs the culture solution by a water flow accompanied by a bubble flow generated by aeration of the supplied exhaust gas.

[0018] A pre-treatment unit that removes impurities from the exhaust gas is provided midway along the gas line GL1. The pre-treatment unit includes a filter device 3, a separator 4, and a catalyst device 5, which are provided in this order from the gasifier 10 side (upstream side). The filter device 3 is used to remove tar, soot, and fine particles smaller than the size of soot. This filter can be, for example, a bag filter.

[0019] The catalytic converter 5 is primarily used to remove oxygen and acetylene. The oxygen removal catalyst may be made of metal particles such as copper (Cu), platinum (Pt), or nickel (Ni). The oxygen removal catalyst is preferably heated to a temperature of 150°C or higher and 400°C or lower. The acetylene removal catalyst may be made of precious metal particles such as palladium (Pd) or platinum (Pt). Removing acetylene prior to deoxidation has the advantage of effectively preventing or reducing the adverse effects of acetylene on the oxygen removal catalyst.

[0020] As shown in FIG. 2 , the separation device 4 includes a first separation section 41 and a second separation section 42. The first separation section 41 and the second separation section 42 each include a first container (first storage section) 410 and a second container (second storage section) 420, which are arranged in this order from upstream to downstream along the gas line GL1. The gas line GL1 is composed of a gas line GL11, a gas line GL12, and a gas line GL13. The first and second numbers are merely for identification purposes and do not limit the order of the lines. Therefore, the carbon dioxide adsorbent may be arranged after the monocyclic aromatic compound adsorbent. The adsorbents are preferably arranged after the monocyclic aromatic compound adsorbent. The above-described order allows for efficient adsorption of the desired substances. The gas line GL11 connects the filter device 3 to the lower port 411 of the first container 410. An air pump (compressor) P1 and a valve V1 are provided in this gas line GL11 in this order from the upstream side.

[0021] The gas line GL12 connects the upper port 412 of the first container 410 and the lower port 421 of the second container 420. Valves V2 and V3 are provided in this gas line GL12, in this order from the upstream side. Furthermore, the gas line GL13 connects the upper port 422 of the second container 420 and the catalytic device 5. Valve V4 is provided in this gas line GL13. With this configuration, the exhaust gas (source gas) can pass through the first container 410 and the second container 420 sequentially via the gas line GL1.

[0022] A gas line GL2 is connected to the lower port 411 of the first container 410. Along this gas line GL2, a valve V5 and a first decompression pump (first decompression unit) P2 are provided, in this order from the first container 410 side. That is, the first decompression pump P2 is connected to the lower port 411 (the side to which exhaust gas is supplied) of the first container 410. Note that decompression here refers to a state in which, when comparing the pressure before and after decompression, the pressure after decompression is calculated to be 20 kPa or more lower than before decompression. The decompression may be calculated to be 30 kPa or more to 400 kPa or less. It is more preferable that the decompression be calculated to be 60 kPa or more to 200 kPa or less before and after decompression. If the decompressed pressure exceeds 400 kPa, it may take too long to achieve decompression. On the other hand, if the decompressed pressure is less than 20 kPa, the decompression effect may be insufficient. A gas line GL3 is connected to the lower port 421 of the second container 420. A valve V6 and a second decompression pump (second decompression unit) P3 are provided along this gas line GL3, in this order from the second container 420 side. That is, the second decompression pump P3 is connected to the lower port 421 (the side to which exhaust gas is supplied) of the second container 420. With this configuration, the first decompression pump P2 can reduce the pressure inside the first container 410 via the gas line GL2, and the second decompression pump P3 can reduce the pressure inside the second container 420 via the gas line GL3. That is, in this embodiment, the first decompression pump (first decompression unit) P2 and the second decompression pump (second decompression unit) P3 form a decompression mechanism that can reduce the pressure inside the first container (first storage unit) 410 and the second container (first storage unit) 420.

[0023] The first container 410 contains (disposed within) a first adsorbent 41a capable of adsorbing at least carbon dioxide in the exhaust gas. The first adsorbent 41a can be separated by decompressing the first container 410 using a first decompression pump P2 to desorb and separate the carbon dioxide from the first adsorbent 41a. That is, in this embodiment, the first separation unit 41 is mainly composed of the first container 410, the first adsorbent 41a, and the first decompression pump P2. The first adsorbent 41a can be composed of one or more of, for example, zeolite, bentonite, sericite, perlite, coral reef rock, vermiculite, silica gel, molecular sieves, activated carbon, MOF, and the like. Among these, the first adsorbent 41a is preferably composed of zeolite. This is because zeolite has particularly excellent carbon dioxide adsorption and desorption capabilities.

[0024] The average particle size of the first adsorbent 41a 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. In this case, the contact area of ​​the first adsorbent 41a with the exhaust gas can be sufficiently large. The shape is not limited to a spherical shape, and may be, for example, a cylindrical shape. In this specification, the average particle size means the average value of the particle sizes of 200 particles arbitrarily selected in one field of view observed with an electron microscope. In this case, the "particle size" means the longest distance between two points on the outline of a particle.

[0025] The BET specific surface area of ​​the first adsorbent 41a is 50 m ２ / g or more 1000m ２ / g or less, and ２ / g or more 800m ２ / g or less is more preferable, and 300m ２ / g or more 700m ２ / g or less. In this case, the contact area of ​​the first adsorbent 41a with the exhaust gas can be sufficiently increased. 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 (JIS R 1626:1996, "Method for measuring the specific surface area of ​​fine ceramic powder by the gas adsorption BET method").

[0026] The average pore diameter of the first adsorbent 41a is preferably 1 Å or more and 20 Å or less, more preferably 3 Å or more and 18 Å or less, and even more preferably 5 Å or more and 15 Å or less. In this case, the contact area of ​​the first adsorbent 41a with the exhaust gas can be sufficiently increased. In this specification, the average pore diameter is a value measured by nitrogen gas adsorption or positron annihilation spectroscopy.

[0027] When the exhaust gas further contains water vapor, sulfur compounds, polycyclic aromatic compounds, and tar, the first separation section 41 is preferably configured to adsorb and separate the water vapor, sulfur compounds, polycyclic aromatic compounds, and tar. This prevents adverse effects on the growth of the gas-utilizing bacteria. Examples of sulfur compounds include hydrogen sulfide, carbonyl sulfide, mercury sulfide, sulfur dioxide, sulfur trioxide, sulfur hexafluoride, sulfur dichloride, and sodium thiosulfate. Examples of polycyclic aromatic compounds include naphthalene, anthracene, phenanthrene, tetracene, pentacene, chrysene, and benzopyrene. In this embodiment, the first container 410 further contains (disposes) a protective agent 41b capable of adsorbing water vapor, sulfur compounds, polycyclic aromatic compounds, and tar and protecting the first adsorbent 41a. In addition to the above-mentioned effects, storing the protective agent 41b in the first container 410 also has the effect of preventing or suppressing deterioration of the performance of the first adsorbent 41a over time. The protective agent 41b may be stored in a container other than the first container 410 that stores the first adsorbent 41a. In this case, the other container is preferably located upstream of the first container 410.

[0028] The protective agent 41b preferably includes a first protective agent 41b1 capable of adsorbing water vapor and sulfur compounds and a second protective agent 41b2 capable of adsorbing polycyclic aromatic compounds and tar. In this case, by using protective agents that differ in at least one of average particle size, BET specific surface area, average pore size, density, temperature resistance, shape, etc. as the first protective agent 41b1 and the second protective agent 41b2, the adsorption and desorption capabilities of water vapor, sulfur compounds, polycyclic aromatic compounds, and tar can be suitably improved. Specifically, as shown in FIG. 2 , the second protective agent 41b2, the first protective agent 41b1, and the first adsorbent 41a are accommodated (arranged) in the first container 410 in this order from the lower port 411 side (the side to which the exhaust gas is supplied). According to this configuration, the protective agent 41b adsorbs water vapor, sulfur compounds, polycyclic aromatic compounds, and tar before the exhaust gas comes into contact with the first adsorbent 41a, thereby more reliably preventing or suppressing the decrease in activity of the first adsorbent 41a over time.

[0029] The first protective agent 41b1 and the second protective agent 41b2 can each be composed of the same materials as those listed for the first adsorbent 41a. Preferably, the first protective agent 41b1 is composed of zeolite, and the second protective agent 41b2 is composed of activated carbon. In this case, the first protective agent 41b1 exhibits excellent adsorption ability for water vapor and sulfur compounds, and the second protective agent 41b2 exhibits excellent adsorption ability for polycyclic aromatic compounds and tar. In addition, in this case, the first adsorbent 41a is preferably composed of zeolite with a larger pore size than the zeolite constituting the first protective agent 41b1. This allows substances that adversely affect the first adsorbent 41a to be removed, thereby enabling the first adsorbent 41a to sufficiently and reliably adsorb and desorb carbon dioxide.

[0030] The second container 420 contains (disposed within) a second adsorbent 42a capable of adsorbing at least monocyclic aromatic compounds in the exhaust gas from which carbon dioxide has been separated in the first separation section 41. The second adsorbent 42a can separate the monocyclic aromatic compounds by reducing the pressure inside the second container 420 using the second decompression pump P3. Examples of monocyclic aromatic compounds include benzene, toluene, ethylbenzene, xylene, aniline, nitrobenzene, cumene, benzenesulfonic acid, chlorobenzene, benzoic acid, trinitrotoluene, and styrene, and may include one or more of these compounds. The second adsorbent 42a may be composed of the same materials as those listed for the first adsorbent 41a. Preferably, the second adsorbent 42a is composed of activated carbon. This is because activated carbon has excellent adsorption and desorption capabilities, particularly for monocyclic aromatic compounds.

[0031] The average particle size of the second adsorbent 42a is preferably 1 mm or more and 20 mm or less, more preferably 2 mm or more and 15 mm or less, and even more preferably 3 mm or more and 10 mm or less. The BET specific surface area of ​​the second adsorbent 42a is 100 m ２ / g or more 2500m ２ / g or less, and ２ / g or more 2000m ２ / g or less is more preferable, and 500m ２ / g or more 1500m ２ / g or less. The average pore diameter of the second adsorbent 42a is preferably 1 Å or more and 300 Å or less, more preferably 5 Å or more and 250 Å or less, and even more preferably 10 Å or more and 200 Å or less. By appropriately setting these numerical ranges, the contact area of ​​the second adsorbent 42a with the exhaust gas can be sufficiently large.

[0032] If the exhaust gas further contains halogen compounds and cyanide compounds, the second separation section 42 is preferably configured to adsorb and separate the halogen compounds and cyanide compounds as well. This prevents adverse effects on the growth of the gas-assimilating bacteria. Examples of halogen compounds include hydrogen chloride, hydrogen fluoride, chlorine, fluorine, and bromine. Examples of cyanide compounds include hydrogen cyanide and nitriles. By appropriately selecting the material, average particle size, BET specific surface area, average pore size, density, temperature resistance, shape, and other factors, the second adsorbent 42a can adsorb not only monocyclic aromatic compounds but also halogen compounds and cyanide compounds.

[0033] A purge gas supply unit 43 that supplies a purge gas is preferably connected to the side opposite to the side to which the exhaust gas is supplied to at least one of the first container 410 and the second container 420. In this embodiment, the purge gas supply unit 43 is connected to the upper port 412 of the first container 410 via a gas line GL41, and is connected to the upper port 422 of the second container 420 via a gas line GL42 branching from the gas line GL41. A valve V7 is provided midway along the gas line GL41, and a valve V8 is provided midway along the gas line GL42.

[0034] According to this configuration, while the first container 410 is depressurized by the first depressurization pump P2 and the second container 420 is depressurized by the second depressurization pump P3, a purge gas is supplied to the first container 410 and the second container 420, thereby cleaning and regenerating the first adsorbent 41a, the first protective agent 41b1, the second protective agent 41b2, and the second adsorbent 42a. The purge gas is preferably a gas that is not easily adsorbed or reacted with the first adsorbent 41a, the first protective agent 41b1, the second protective agent 41b2, and the second adsorbent 42a. Specific examples of the purge gas include nitrogen gas and rare gases (argon gas, helium gas). These gases may be used alone or in combination (mixture) of two or more.

[0035] A thermometer TE is connected to each of the first container 410 and the second container 420. This makes it possible to measure the temperature inside the first container 410 and the temperature inside the second container 420. A pressure gauge PT is connected to the lower port 411 and the upper port 412 of the first container 410, and the lower port 421 and the upper port 422 of the second container 420, respectively. This makes it possible to measure the pressure of the gas supplied to and discharged from the first container 410, and the pressure of the gas supplied to and discharged from the second container 420. A hygrometer AE is connected midway along the gas line GL12. This makes it possible to measure the humidity of the exhaust gas passing through the gas line GL12.

[0036] The exhaust gas from which the monocyclic aromatic compounds have been separated in the second separation section 42 is supplied to the culture tank 2. The concentration of carbon dioxide contained in the exhaust gas supplied to the culture tank 2 is preferably 0.1 vol% to 30 vol%, more preferably 0.3 vol% to 25 vol%, even more preferably 0.5 vol% to 20 vol%, particularly preferably 0.8 vol% to 15 vol%, and most preferably 1 vol% to 10 vol%.

[0037] The concentration of carbon monoxide contained in the exhaust gas supplied to the culture tank 2 is preferably 10% by volume to 80% by volume, more preferably 15% by volume to 50% by volume, and even more preferably 20% by volume to 45% by volume. The concentration of hydrogen contained in the exhaust gas supplied to the culture tank 2 is preferably 1% by volume to 45% by volume, more preferably 5% by volume to 35% by volume, and even more preferably 10% by volume to 30% by volume.

[0038] Furthermore, the concentration of nitrogen contained in the exhaust gas supplied to the culture tank 2 is preferably 30% by volume or less, more preferably 1% by volume or more and 25% by volume or less, and even more preferably 5% by volume or more and 20% by volume or less. According to the above configuration, the exhaust gas passes through the pretreatment unit, whereby the concentration of carbon monoxide is increased, and therefore organic substances can be efficiently produced in the culture tank 2.

[0039] In the culture tank 2, organic substances are produced from carbon monoxide contained in the supplied exhaust gas by the action of gas-assimilating bacteria. A purification device 6 is connected to the culture tank 2 via a liquid line LL. This purification device 6 is a device that purifies organic substances from an organic substance-containing liquid. Examples of such purification devices 6 include a distillation device, a treatment device including a pervaporation membrane, a zeolite dehydration membrane, a treatment device including an organic membrane, a treatment device that removes low-boiling substances with a boiling point lower than that of organic substances, a treatment device that removes high-boiling substances with a boiling point higher than that of organic substances, and a treatment device including an ion exchange membrane. These devices may be used alone or in combination of two or more types.

[0040] When using a distillation apparatus, the temperature inside the distillation apparatus during the distillation of organic substances (especially ethanol) is not particularly limited, but is preferably 100°C or lower, and more preferably 70°C or higher and 95°C or lower. By setting such a temperature, separation of the necessary organic substances from other components, i.e., distillation (purification) of the organic substances can be more reliably performed. The pressure inside the distillation apparatus during the distillation of the organic substances may be atmospheric pressure, but is preferably less than atmospheric pressure (reduced pressure distillation), more preferably 60 to 95 kPaA. Setting such a pressure can improve the separation efficiency of the organic substances and, therefore, the yield of the organic substances. The yield of the organic substances (concentration of the organic substances contained in the purified product) is preferably 90% by weight or higher, more preferably 99% by weight or higher, and even more preferably 99.5% by weight or higher.

[0041] Examples of organic substances obtained in this manner include monools such as methanol and ethanol, diols such as 2,3-butanediol, acetic acid, lactic acid, isoprene, and butadiene. Monools or diols having 1 to 4 carbon atoms are preferred, and ethanol is more preferred. Such organic substances can be used, for example, as raw materials for resin materials, rubber materials, and the like, and can also be used as various solvents, disinfectants, or fuels. High-concentration ethanol can be used as fuel ethanol to be mixed with gasoline, etc., and can also be used, for example, as a raw material for cosmetics, beverages, chemicals, fuel (jet fuel), etc., and as an additive for foods, etc., making it extremely versatile.

[0042] Next, a method of using the production system 100 of the first embodiment (a method of producing an organic substance) will be described. [1] First, the exhaust gas (a raw material gas containing carbon monoxide, carbon dioxide, monocyclic aromatic compounds, and other gas components) discharged from the gasification furnace 10 is supplied to the filter device 3. At this time, minute solid matter (e.g., tar, soot, etc.) contained in the exhaust gas is removed.

[0043] [2] Next, valves V1, V2, V3, and V4 are opened, valves V5, V6, V7, and V8 are closed, and the air pump P1 is operated. As a result, the exhaust gas discharged from the filter device 3 passes through the first separation section 41 (first container 410). At this time, polycyclic aromatic compounds and tar are adsorbed by the second protective agent 41b2, and water vapor and sulfur compounds are adsorbed by the first protective agent 41b1. By removing these substances, deterioration of the performance of the first adsorbent 41a over time can be effectively prevented or suppressed. Carbon dioxide is then adsorbed by the first adsorbent 41a. The pressure of the exhaust gas generated by the air pump P1 is preferably 0.1 MPaG or less, and more preferably 0.01 MPaG or more and 0.05 MPaG or less.

[0044] [3] The exhaust gas discharged from the first separation section 41 and from which carbon dioxide and other compounds have been separated then passes through the second separation section 42 (second container 420). At this time, the monocyclic aromatic compounds, halogen compounds, and cyan compounds are adsorbed by the second adsorbent 42a. [4] Next, the exhaust gas discharged from the second separation section 42 passes through the catalytic device 5. At this time, oxygen and acetylene are removed from the exhaust gas.

[0045] [5] The exhaust gas from which the monocyclic aromatic compounds and the like have been separated is then supplied to the culture tank 2. In the culture tank 2, organic substances are produced from the carbon monoxide contained in the supplied exhaust gas by the action of the gas-assimilating bacteria. This results in an organic substance-containing liquid containing the organic substances. Here, the temperature at which the organic substances are produced from carbon monoxide in the culture tank 2 (the culture temperature of the gas-assimilating bacteria) is not particularly limited, but is preferably 25°C or higher and 50°C or lower. [6] Next, the organic substance-containing liquid obtained in the culture tank 2 is supplied to the purification device 6 via the liquid line LL. In the purification device 6, the organic substances contained in the organic substance-containing liquid are purified, and a purified product containing the organic substances at a high concentration is obtained.

[0046] [7] When the performance of the second protective agent 41b2, the first protective agent 41b1, and the first adsorbent 41a deteriorates after a predetermined time has elapsed, the valves V1 and V2 are closed, the valve V5 is opened, and the first decompression pump P2 is operated. This decompresses and separates carbon dioxide and other contaminants from the first adsorbent 41a and other contaminants in the first container 410. That is, the carbon dioxide and other contaminants are decompressed and separated from the first adsorbent 41a and other contaminants by utilizing pressure changes. As a result, off-gas containing carbon dioxide and other contaminants can be recovered. The pressure inside the first container 410 reduced by the first decompression pump P2 is not particularly limited, but is preferably -10 kPaG or less, and more preferably -30 kPaG or less. By using the first adsorbent 41a, the first protective agent 41b1, and the second protective agent 41b2 described above, carbon dioxide and other contaminants can be sufficiently decompressed without increasing the degree of decompression, thereby reducing power energy.

[0047] At this time, the valve V7 may be opened to supply a purge gas from the purge gas supply unit 43 to the first container 410. This increases the efficiency of desorbing carbon dioxide and the like from the first adsorbent 41a, etc., and also enables cleaning of the first adsorbent 41a, etc. Furthermore, by optimizing the materials, average particle size, BET specific surface area, average pore size, density, temperature resistance, shape, and the like of the first adsorbent 41a, the first protective agent 41b1, and the second protective agent 41b2, the degree of decompression by the first decompression pump P2 may be reduced, or the first decompression pump P2 may be omitted.

[0048] [8] Similarly, when the performance of the second adsorbent 42a deteriorates after a predetermined time has elapsed, valves V3 and V4 are closed, valve V6 is opened, and the second decompression pump P3 is operated. This causes monocyclic aromatic compounds and the like to be desorbed and separated from the second adsorbent 42a and the like in the second container 420. That is, the monocyclic aromatic compounds and the like are desorbed and separated from the second adsorbent 42a by utilizing a change in pressure. As a result, off-gas containing monocyclic aromatic compounds and the like can be recovered. The pressure inside the second container 420 reduced by the second decompression pump P3 is not particularly limited, but is preferably −10 kPaG or less, and more preferably −30 kPaG or less. By using the second adsorbent 42a as described above, monocyclic aromatic compounds and the like can be sufficiently desorbed without increasing the degree of decompression, thereby reducing power energy.

[0049] At this time, the valve V8 may be opened to supply purge gas from the purge gas supply unit 43 to the second container 420. This increases the efficiency of desorbing monocyclic aromatic compounds and the like from the second adsorbent 42a, and also enables cleaning of the second adsorbent 42a, etc. Furthermore, by optimizing the material, average particle size, BET specific surface area, average pore size, density, temperature resistance, shape, etc. of the second adsorbent 42a, it is possible to reduce the degree of decompression by the second decompression pump P3 or even omit the second decompression pump P3.

[0050] The above-described configuration contributes to reducing thermal energy because it is not necessary to heat the purge gas supplied to the first container 410 and the second container 420. Furthermore, by appropriately setting the materials, average particle size, BET specific surface area, average pore size, filling amount, and arrangement order of the first adsorbent 41 a, the second adsorbent 42 a, the first protective agent 41 b 1, and the second protective agent 41 b 2, it is possible to reduce the size of the separation device 4, the diameter of the connecting pipes, the pump capacity, and ultimately the size of the production system 100.

[0051] Second Embodiment Next, a system for producing an organic substance according to a second embodiment will be described. The system for producing an organic substance according to the second embodiment will be described below, focusing on differences from the system for producing an organic substance according to the first embodiment, and a description of similar points will be omitted. Figure 3 is a schematic diagram showing the configuration of the system for producing an organic substance according to the second embodiment. The production system 100 according to the second embodiment has a different configuration for the separation device 4, and is otherwise similar to the production system 100 according to the first embodiment.

[0052] In the manufacturing system 100 shown in FIG. 3 , the first separation unit 41 has two first containers 410, and the second separation unit 42 has two second containers 420. The manufacturing system 100 of the second embodiment also provides the same functions and effects as the manufacturing system 100 of the first embodiment. In particular, since the second embodiment includes two first containers 410 and two second containers 420, when a purge gas is supplied to one of the two first containers 410, exhaust gas can be supplied to the other. Similarly, when a purge gas is supplied to one of the two second containers 420, exhaust gas can be supplied to the other. This allows the manufacturing system 100 to be continuously operated without shutting down.

[0053] Furthermore, in the second embodiment, there are provided a valve V410 that connects the upper ports 412 of the two first containers 410 together, and a valve V420 that connects the upper ports 422 of the two second containers 420 together. These valves V410 and V420 are pressure equalization valves that reduce sudden pressure fluctuations and gas loss when gas adsorption / desorption processes are repeated between the two first containers 410 and between the two second containers 420.

[0054] Third Embodiment Next, a system for producing an organic substance according to a third embodiment will be described. The system for producing an organic substance according to the third embodiment will be described below, focusing on differences from the systems for producing an organic substance according to the first and second embodiments, and a description of similar points will be omitted. Figure 4 is a schematic diagram showing the configuration of the system for producing an organic substance according to the third embodiment.

[0055] The manufacturing system 100 of the third embodiment is similar to the manufacturing system 100 of the first embodiment except for the configuration of the separation device 4. The manufacturing system 100 shown in Fig. 4 has a first container 410 (first separation section 41) and a second container 420 (second separation section 42) connected in series, and is configured so that the first container (first storage section) 410 and the second container (first storage section) 420 can be depressurized by a single second depressurization pump P3 provided midway along the gas line GL13. That is, in the third embodiment, the single second depressurization pump P3 constitutes a depressurization mechanism.

[0056] The manufacturing system 100 of the third embodiment also provides the same actions and effects as the manufacturing system 100 of the first embodiment. In particular, in the manufacturing system 100 of the third embodiment, by adjusting the switching timing of the valves V1 and V7 and the switching timing of the valves V9 and V10, it is possible to separate and recover the exhaust gas from which unnecessary gas components have been removed and the off-gas containing the unnecessary gas components using a single second decompression pump P3.

[0057] <Fourth Embodiment> Next, an organic substance production system according to a fourth embodiment will be described. The organic substance production system according to the fourth embodiment will be described below, focusing on differences from the organic substance production systems of the first to third embodiments, and a description of similar points will be omitted. Figure 5 is a schematic diagram showing the configuration of the organic substance production system according to the fourth embodiment. Figure 6 is a schematic diagram showing the configuration of a separation device in the organic substance production system according to the fourth embodiment.

[0058] The manufacturing system 100 of the fourth embodiment is similar to the manufacturing system 100 of the third embodiment except for the configuration of the separation device 4. The manufacturing system 100 shown in FIG. 4 includes one container 400. As shown in FIG. 6, a partition wall 403 is disposed midway along the longitudinal direction of the container 400, dividing the container 400 into a first storage space (first storage section) 400a on the left side and a second storage space (second storage section) 400b on the right side. A first adsorbent 41a is disposed in the first storage space 400a, and a second adsorbent 42a is disposed in the second storage space 400b.

[0059] Therefore, in this embodiment, the left region of the container 400 constitutes the first separation section 41, and the right region constitutes the second separation section 42. A valve element 404 is provided in the center of the partition wall 403. This valve element 404 opens in response to the pressure difference between the first storage space 400a and the second storage space 400b, thereby connecting the two spaces 400a, 400b to each other. The valve element 404 preferably has high heat resistance and can be formed, for example, by a check valve, a duckbill valve, or the like. A filter may be provided instead of the valve element 404.

[0060] The container 400 is configured to be able to reduce the pressure inside by a single second decompression pump P3 provided midway along the gas line GL13. That is, in the fourth embodiment as well, a single second decompression pump P3 constitutes a decompression mechanism. The manufacturing system 100 of the fourth embodiment also achieves the same functions and effects as the manufacturing systems 100 of the first to third embodiments. In particular, in the manufacturing system 100 of the fourth embodiment as well, by adjusting the switching timing of the valves V1 and V7 and the switching timing of the valves V9 and V10, it is possible to separate and recover the exhaust gas from which unnecessary gas components have been removed and the off-gas containing the unnecessary gas components using a single second decompression pump P3.

[0061] The organic substance production system, organic substance production apparatus, and organic substance production method described above enable production of organic substances while reducing the thermal energy used in pretreatment. Furthermore, by appropriately configuring the adsorbent, power energy can be reduced. While the above embodiment describes an example in which a pump is used as the pressure reduction mechanism, the pressure reduction mechanism is not limited to a pump. For example, the pressure reduction mechanism can be configured with a cooling device capable of reducing the pressure in the first and second storage units by cooling any location in the production system 100 (production apparatus 1). In all examples of the present invention, the pre-pressure state was 50 kPaG to 100 kPaG, and the post-pressure state was -10 kPaG to -100 kPaG. Note that kPaG is a unit of gauge pressure, and gauge pressure is absolute pressure minus atmospheric pressure. Furthermore, the present invention may be provided in the following forms.

[0062] (1) A system for producing an organic substance, the system comprising: a gas generation unit that generates a raw material gas containing at least carbon monoxide, carbon dioxide, and monocyclic aromatic compounds; a first separation unit that has a first adsorbent capable of adsorbing at least the carbon dioxide in the raw material gas and a first storage unit in which the first adsorbent is disposed, and that is capable of separating and separating the carbon dioxide from the first adsorbent by reducing the pressure inside the first storage unit; a second separation unit that has a second adsorbent capable of adsorbing at least the monocyclic aromatic compounds in the raw material gas and a second storage unit in which the second adsorbent is disposed, and that is capable of separating and separating the monocyclic aromatic compounds from the second adsorbent by reducing the pressure inside the second storage unit; a decompression mechanism that is capable of reducing the pressure inside the first storage unit and the second storage unit; and a culture tank that supplies the raw material gas from which the carbon dioxide and the monocyclic aromatic compounds have been separated, and that produces an organic substance from the carbon monoxide contained in the supplied raw material gas by the action of gas-assimilating bacteria.

[0063] (2) The organic substance production system according to (1) above, wherein the first adsorbent is composed of zeolite.

[0064] (3) In the organic substance production system described in (1) or (2) above, the raw material gas further contains water vapor, sulfur compounds, polycyclic aromatic compounds, and tar, and the first separation section is configured to be able to adsorb and separate the water vapor, the sulfur compounds, the polycyclic aromatic compounds, and the tar.

[0065] (4) In the organic substance manufacturing system described in (3) above, the first storage section further comprises a protective agent capable of adsorbing the water vapor, the sulfur compounds, the polycyclic aromatic compounds, and the tar, and for protecting the first adsorbent.

[0066] (5) In the organic substance manufacturing system described in (4) above, the protective agent includes a first protective agent capable of adsorbing the water vapor and the sulfur compounds, and a second protective agent capable of adsorbing the polycyclic aromatic compounds and the tar.

[0067] (6) In the organic substance manufacturing system described in (5) above, the first storage section is arranged with the second protective agent, the first protective agent, and the first adsorbent in that order from the side to which the raw material gas is supplied.

[0068] (7) In the organic substance production system described in (5) or (6) above, the first protective agent is composed of zeolite, and the second protective agent is composed of activated carbon.

[0069] (8) In the organic substance production system described in (7) above, the first adsorbent is composed of zeolite having a larger pore size than the zeolite constituting the first protective agent.

[0070] (9) In the organic substance manufacturing system described in any one of (1) to (8) above, the pressure reduction mechanism has a first pressure reduction section that can reduce the pressure inside the first container, and the first pressure reduction section is connected to the side of the first container to which the raw material gas is supplied.

[0071] (10) In the organic substance production system described in any one of (1) to (9) above, the raw material gas further contains a halogen compound and a cyanide compound, and the second separation section is configured to be able to adsorb and separate the halogen compound and the cyanide compound as well.

[0072] (11) In the organic substance manufacturing system described in (10) above, the pressure reduction mechanism has a second pressure reduction section that can reduce the pressure inside the second storage section, and the second pressure reduction section is connected to the side of the second storage section to which the raw material gas is supplied.

[0073] (12) The organic substance production system according to any one of (1) to (11) above, wherein the second adsorbent is composed of activated carbon.

[0074] (13) In the organic substance production system described in any one of (1) to (12) above, a purge gas supply unit that supplies a purge gas is connected to at least one of the first container and the second container on the side opposite to the side to which the raw material gas is supplied.

[0075] (14) An organic substance manufacturing apparatus used in connection with a gas generation unit that generates a raw material gas containing at least carbon monoxide, carbon dioxide, and monocyclic aromatic compounds, the organic substance manufacturing apparatus comprising: a first separation unit having a first adsorbent capable of adsorbing at least the carbon dioxide in the raw material gas and a first storage unit in which the first adsorbent is disposed, and capable of separating the carbon dioxide from the first adsorbent by reducing the pressure inside the first storage unit; a second separation unit having a second adsorbent capable of adsorbing at least the monocyclic aromatic compounds in the raw material gas and a second storage unit in which the second adsorbent is disposed, and capable of separating the monocyclic aromatic compounds from the second adsorbent by reducing the pressure inside the second storage unit; a pressure reduction mechanism that can reduce the pressure inside the first storage unit and the second storage unit; and a culture tank that supplies the raw material gas from which the carbon dioxide and the monocyclic aromatic compounds have been separated, and that produces organic substances from the carbon monoxide contained in the supplied raw material gas by the action of gas-assimilating bacteria.

[0076] (15) A method for producing an organic substance, comprising: adsorbing carbon dioxide from a source gas containing at least carbon monoxide, carbon dioxide, and a monocyclic aromatic compound with a first adsorbent, and then utilizing a change in pressure to separate the carbon dioxide by desorbing it from the first adsorbent; adsorbing the monocyclic aromatic compound from the source gas with a second adsorbent, and then utilizing a change in pressure to separate the monocyclic aromatic compound from the second adsorbent; supplying the source gas from which the carbon dioxide and the monocyclic aromatic compound have been separated; and producing an organic substance from the carbon monoxide contained in the supplied source gas by the action of gas-assimilating bacteria. Of course, this is not limited to this.

[0077] As described above, various embodiments of the present invention have been described, but these are presented as examples and do not limit the scope of the invention in any way. The novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. Such embodiments and their modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the inventions and their equivalents as set forth in the claims.

[0078] For example, the organic substance production system, organic substance production apparatus, and organic substance production method of the present invention may each combine any of the configurations of the first to fourth embodiments. Furthermore, the organic substance production system and organic substance production apparatus of the present invention may each have any additional configuration compared to the above embodiments, may be replaced with any configuration that exhibits a similar function, or some of the configurations may be omitted. Furthermore, the organic substance production method of the present invention may each have any additional process compared to the above embodiments, may be replaced with any process that exhibits a similar function, or may be omitted.

[0079] 100: organic substance production system, 10: gasification furnace, 1: organic substance production apparatus, 2: culture tank, 3: filter device, 4: separation device, 400: container, 400a: first storage space (first storage section), 400b: second storage space (second storage section), 401: lower port, 402: upper port, 403: partition wall, 404: valve body, 41: first separation section, 410: first container (first storage section), 411: lower port, 412: upper port, 41a: first adsorbent, 41b: protective agent, 41b1: first protective agent, 41b2: second protective agent, 42: second separation section, 420: second container (second storage section), 421: lower port, 422: upper Port, 42a: second adsorbent, 43: purge gas supply unit, 5: catalyst device, 6: purification device, GL1: gas line, GL11: gas line, GL12: gas line, GL13: gas line, GL2: gas line, GL3: gas line, GL41: gas line, GL42: gas line, LL: liquid line, P1: gas supply pump, P2: first pressure reducing pump, P3: second pressure reducing pump, V1: valve, V2: valve, V3: valve, V4: valve, V5: valve, V6: valve, V7: valve, V8: valve, V9: valve, V10: valve, V410: valve, V420: valve, AE: hygrometer, PT: pressure gauge, TE: thermometer

Claims

1. 1. A system for producing organic materials, comprising: a gas generating unit that generates a raw material gas containing at least carbon monoxide, carbon dioxide, and a monocyclic aromatic compound; a first separation unit including a first adsorbent capable of adsorbing at least the carbon dioxide in the raw material gas and a first storage unit in which the first adsorbent is disposed, the first separation unit being capable of separating and separating the carbon dioxide from the first adsorbent by reducing the pressure inside the first storage unit; a second separation unit including a second adsorbent capable of adsorbing at least the monocyclic aromatic compounds in the source gas and a second storage unit in which the second adsorbent is disposed, the second separation unit being capable of separating and separating the monocyclic aromatic compounds from the second adsorbent by reducing the pressure inside the second storage unit; a decompression mechanism capable of decompressing the first storage section and the second storage section; a culture tank for supplying the raw material gas from which the carbon dioxide and the monocyclic aromatic compounds have been separated, and for producing an organic substance from the carbon monoxide contained in the supplied raw material gas by the action of gas-assimilating bacteria.

2. 2. The organic substance manufacturing system according to claim 1, A system for producing an organic substance, wherein the first adsorbent is composed of zeolite.

3. 2. The organic substance manufacturing system according to claim 1, the raw material gas further contains water vapor, a sulfur compound, a polycyclic aromatic compound, and tar; The system for producing an organic substance, wherein the first separation unit is configured to be able to adsorb and separate the water vapor, the sulfur compounds, the polycyclic aromatic compounds, and the tar.

4. 4. The organic substance production system according to claim 3, The organic substance manufacturing system further comprises a protective agent disposed in the first storage section, the protective agent being capable of adsorbing the water vapor, the sulfur compounds, the polycyclic aromatic compounds, and the tar and protecting the first adsorbent.

5. 5. The organic substance production system according to claim 4, The protective agent includes a first protective agent capable of adsorbing the water vapor and the sulfur compounds, and a second protective agent capable of adsorbing the polycyclic aromatic compounds and the tar.

6. 6. The organic substance production system according to claim 5, A system for producing an organic substance, wherein the first storage unit has the second protective agent, the first protective agent, and the first adsorbent arranged in this order from the side to which the raw material gas is supplied.

7. 6. The organic substance production system according to claim 5, A system for producing an organic substance, wherein the first protective agent is composed of zeolite, and the second protective agent is composed of activated carbon.

8. 8. The organic substance manufacturing system according to claim 7, A system for producing an organic substance, wherein the first adsorbent is composed of zeolite having a pore size larger than that of the zeolite constituting the first protective agent.

9. 2. The organic substance manufacturing system according to claim 1, the pressure reducing mechanism has a first pressure reducing section that can reduce the pressure inside the first housing section, The system for producing an organic substance, wherein the first pressure reducing section is connected to a side of the first container section to which the raw material gas is supplied.

10. 2. The organic substance manufacturing system according to claim 1, the source gas further contains a halogen compound and a cyanide compound, The system for producing an organic substance, wherein the second separation unit is configured to be able to adsorb and separate the halogen compounds and the cyanide compounds as well.

11. The organic substance manufacturing system according to claim 10, the pressure reducing mechanism has a second pressure reducing section that can reduce the pressure inside the second accommodation section, The second pressure reducing section is connected to the side of the second container section to which the raw material gas is supplied.

12. 2. The organic substance manufacturing system according to claim 1, A system for producing organic substances, wherein the second adsorbent is composed of activated carbon.

13. 2. The organic substance manufacturing system according to claim 1, A system for producing an organic substance, wherein a purge gas supply unit that supplies a purge gas is connected to at least one of the first container unit and the second container unit on the side opposite to the side to which the raw material gas is supplied.

14. An apparatus for producing an organic substance that is used by being connected to a gas generating unit that generates a raw material gas containing at least carbon monoxide, carbon dioxide, and a monocyclic aromatic compound, a first separation unit including a first adsorbent capable of adsorbing at least the carbon dioxide in the raw material gas and a first storage unit in which the first adsorbent is disposed, the first separation unit being capable of separating and separating the carbon dioxide from the first adsorbent by reducing the pressure inside the first storage unit; a second separation unit including a second adsorbent capable of adsorbing at least the monocyclic aromatic compounds in the source gas and a second storage unit in which the second adsorbent is disposed, the second separation unit being capable of separating and separating the monocyclic aromatic compounds from the second adsorbent by reducing the pressure inside the second storage unit; a decompression mechanism capable of decompressing the first storage section and the second storage section; a culture tank for supplying the raw material gas from which the carbon dioxide and the monocyclic aromatic compounds have been separated, and for producing an organic substance from the carbon monoxide contained in the supplied raw material gas by the action of gas-assimilating bacteria.

15. 1. A method for producing an organic substance, comprising: adsorbing the carbon dioxide from a source gas containing at least carbon monoxide, carbon dioxide, and a monocyclic aromatic compound with a first adsorbent, and separating the carbon dioxide by desorbing it from the first adsorbent using a pressure change; adsorbing the monocyclic aromatic compounds from the source gas with a second adsorbent, and separating the monocyclic aromatic compounds by desorbing them from the second adsorbent using a pressure change; a raw material gas from which the carbon dioxide and the monocyclic aromatic compounds have been separated, and an organic substance is produced from the carbon monoxide contained in the raw material gas by the action of gas-assimilating bacteria.