JP7265571B2 - CARBON COMPOUND MANUFACTURING DEVICE AND CARBON COMPOUND MANUFACTURE METHOD - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for producing a carbon compound and a method for producing a carbon compound.

Carbon compounds such as ethanolamine and ethylene glycol are liquid and easy to transport, and are widely used as basic chemical raw materials for various chemical products. Ethanolamine is used, for example, as a raw material for detergents, cosmetics, and agricultural chemicals. Ethylene glycol is used, for example, as a raw material for polyethylene terephthalate, detergents, and pharmaceuticals.

Ethanolamine is produced, for example, by the reaction of ethylene oxide and ammonia (eg, Patent Document 1). Also, ethylene glycol is produced, for example, by the reaction of ethylene oxide and water (eg, Patent Document 2). Ethylene oxide is obtained, for example, by gas-phase oxidation of ethylene (eg, Patent Document 3).

Japanese Patent No. 4205963 JP-A-54-125606 JP-A-58-174238

However, conventionally, basic chemical raw materials composed of these carbon compounds have been produced by petrochemical industrial technology, and are being forced to be reconsidered because of their great burden on the global environment. Therefore, it is significant to reduce the environmental load in the production of carbon compounds such as ethanolamine and ethylene glycol.

An object of the present invention is to provide a carbon compound manufacturing apparatus and a carbon compound manufacturing method capable of manufacturing carbon compounds such as ethanolamine and ethylene glycol from carbon dioxide and reducing the environmental load.

The present invention employs the following aspects.
(1) A carbon compound manufacturing apparatus according to an aspect of the present invention (for example, the carbon compound manufacturing apparatus 100 of the embodiment) includes a recovery apparatus for recovering carbon dioxide (for example, the recovery apparatus 1 of the embodiment), An electrochemical reactor that electrochemically reduces carbon dioxide recovered by a recovery device (for example, the electrochemical reactor 2 of the embodiment), and ethanolamine from ethylene produced by reducing carbon dioxide in the electrochemical reactor and an ethanolamine synthesizer (for example, the ethanolamine synthesizer 4 of the embodiment) that synthesizes the ethylene produced by the carbon dioxide reduction in the electrochemical reactor and the by-produced oxygen A first reactor (for example, the first reactor 42 of the embodiment) in which ethylene oxide is obtained by reacting the For example, the second reactor 43 of the embodiment) and a third reactor (for example, the implementation and a third reactor 44) of the form
(2) A carbon compound manufacturing apparatus according to an aspect of the present invention (for example, the carbon compound manufacturing apparatus 200 of the embodiment) includes a recovery apparatus for recovering carbon dioxide (for example, the recovery apparatus 1 of the embodiment), An electrochemical reactor that electrochemically reduces carbon dioxide recovered by a recovery device (for example, the electrochemical reactor 2 of the embodiment); and ethylene glycol from ethylene produced by reducing carbon dioxide in the electrochemical reactor. and an ethylene glycol synthesizer (for example, the ethylene glycol synthesizer 6 of the embodiment) that synthesizes the ethylene glycol produced by the carbon dioxide reduction of the electrochemical reactor and the by-produced oxygen to obtain ethylene oxide (for example, the first reactor 42 of the embodiment), and a fourth reactor (for example, the first reactor of the embodiment to obtain ethylene glycol by reacting the ethylene oxide with water). 4 reactors 45).
(3) The recovery device includes an absorption part (for example, the absorption part 12 of the embodiment) that brings the carbon dioxide gas into contact with the absorption liquid and causes the absorption liquid to absorb the carbon dioxide, and the absorption liquid that has absorbed the carbon dioxide. A carbon-increasing reactor (e.g., an embodiment form of the carbon-enhancing reactor 5), and the release section may heat the absorbent using heat generated by the multimerization reaction in the carbon-enhancing reactor.
(4) A method for producing a carbon compound according to an aspect of the present invention includes a step of recovering carbon dioxide, a step of electrochemically reducing the recovered carbon dioxide to obtain ethylene, and ethylene produced by the carbon dioxide reduction. and by-produced oxygen to obtain ethylene oxide, react hydrogen by-produced by carbon dioxide reduction with nitrogen to obtain ammonia, and then react the ethylene oxide and the ammonia to obtain ethanolamine. and
(5) A method for producing a carbon compound according to an aspect of the present invention includes steps of recovering carbon dioxide, electrochemically reducing the recovered carbon dioxide to obtain ethylene, and producing ethylene by the carbon dioxide reduction. and a step of reacting with oxygen by-produced to obtain ethylene oxide, and then reacting the ethylene oxide with water to obtain ethylene glycol.
(6) The method for producing a carbon compound of (4) or (5) may further include a step of multimerizing ethylene produced by carbon dioxide reduction.

According to the aspects (1) to (6), carbon compounds such as ethanolamine and ethylene glycol can be produced from carbon dioxide, and the environmental load can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS It is the block diagram which showed the manufacturing apparatus of the carbon compound of embodiment. FIG. 2 is a cross-sectional view showing an example of an electrochemical reaction device in the carbon compound manufacturing apparatus of FIG. 1; BRIEF DESCRIPTION OF THE DRAWINGS It is the block diagram which showed the manufacturing apparatus of the carbon compound of embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the dimensions and the like of the drawings illustrated in the following description are only examples, and the present invention is not necessarily limited to them, and can be implemented with appropriate changes within the scope of not changing the gist of the present invention. .

[First embodiment]
(Carbon compound manufacturing equipment)
As shown in FIG. 1, an apparatus 100 for producing a carbon compound according to one embodiment of the present invention (hereinafter also simply referred to as "production apparatus 100") includes a recovery device 1, an electrochemical reaction device 2, and a power storage device. 3, an ethanolamine synthesis device 4, and a carbon enrichment reactor 5. The recovery device 1 includes an enrichment section 11 , an absorption section 12 and an emission section 13 . The power storage device 3 includes a conversion section 31 and a storage section 32 electrically connected to the conversion section 31 . The ethanolamine synthesis apparatus 4 includes a separation section 41 , a first reactor 42 , a second reactor 43 and a third reactor 44 . The coal-enhancing reactor 5 includes a reactor 51 and a gas-liquid separator 52 .

In the manufacturing apparatus 100 , the concentration section 11 and the absorption section 12 are connected by the gas flow path 61 . The absorbing section 12 and the discharging section 13 are connected by liquid flow paths 62 and 63 . The discharge part 13 and the electrochemical reaction device 2 are connected by a gas flow path 64 . The electrochemical reaction device 2 and the separation section 41 are connected by a gas flow path 65 . The electrochemical reactor 2 and the first reactor 42 are connected by a gas flow path 66 . The separation section 41 and the first reactor 42 are connected by a gas flow path 67 . The first reactor 42 and the third reactor 44 are connected by a gas flow path 68 . The separation section 41 and the second reactor 43 are connected by a gas flow path 69 . The second reactor 43 and the third reactor 44 are connected by a liquid channel 70 . The separation section 41 and the reactor 51 are connected by a gas flow path 71 . The reactor 51 and the gas-liquid separator 52 are connected by a gas channel 72 and a gas channel 73 . A heat medium circulation flow path 74 is provided between the reactor 51 and the discharge section 13 . The concentration section 11 and the gas-liquid separator 52 are connected by a gas flow path 75 .

These flow paths are not particularly limited, and known pipes and the like can be used as appropriate. In the gas flow paths 61, 64, 69, 71 to 73, 75, air supply means such as compressors, pressure reducing valves, measuring devices such as pressure gauges, etc. can be appropriately installed. Further, in the liquid flow paths 62 , 63 , 70 , liquid feeding means such as pumps, measuring instruments such as flowmeters, etc. can be appropriately installed.

The recovery device 1 is a device for recovering carbon dioxide.
The concentration unit 11 is supplied with a carbon dioxide-containing gas G1 such as the atmosphere or an exhaust gas. In the concentrating section 11, the carbon dioxide of the gas G1 is condensed. As the concentration unit 11, a known concentration device can be adopted as long as it can concentrate carbon dioxide. For example, a membrane separation device using a difference in permeation speed with respect to a membrane, chemical or physical adsorption and desorption are used. Adsorption separation equipment can be used. Among them, a membrane separation device capable of separating carbon dioxide is preferable as the concentration unit 11 from the viewpoint of energy efficiency.

Concentrated gas G<b>2 in which carbon dioxide is concentrated in concentrating section 11 is sent to absorbing section 12 through gas channel 61 . Also, the separated gas G3 separated from the concentrated gas G2 is sent to the gas-liquid separator 52 through the gas flow path 75 .

In the absorption section 12, the carbon dioxide gas in the concentrated gas G2 supplied from the concentration section 11 contacts the absorption liquid A, and the carbon dioxide is dissolved in the absorption liquid A and absorbed. The method of bringing the carbon dioxide gas and the absorbent A into contact is not particularly limited, and for example, a method of blowing the concentrated gas G2 into the absorbent A to cause bubbling can be exemplified.
As the absorbing liquid A, any liquid can be used as long as it can absorb carbon dioxide and release carbon dioxide gas when heated. For example, ethanolamine can be exemplified.

The absorbent B in which carbon dioxide has been absorbed in the absorbing section 12 is sent to the discharging section 13 through the liquid flow path 62 . In the discharge section 13, the absorption liquid B is heated by heat exchange between the absorption liquid B and the heating medium N heated by utilizing the heat generated in the reactor 51 of the coal-increase reaction device 5 described later. Carbon dioxide gas G3 is released. As the discharge part 13, for example, a known heat exchanger can be used.
The carbon dioxide gas G4 released from the release portion 13 is sent to the electrochemical reaction device 2 through the gas flow path 64. As shown in FIG.

The electrochemical reaction device 2 is a device for electrochemically reducing carbon dioxide. As shown in FIG. 2, the electrochemical reaction device 2 includes a cathode 21, an anode 22, a liquid channel structure 23 for forming a liquid channel 23a, and a gas channel in which a gas channel 24a is formed. It includes a structure 24 , a gas channel structure 25 in which a gas channel 25 a is formed, a power feeder 26 and a power feeder 27 .

In the electrochemical reaction device 2, a power feeder 26, a gas channel structure 24, a cathode 21, a liquid channel structure 23, an anode 22, a gas channel structure 25, and a power feeder 27 are stacked in this order. A plurality of slits are formed in parallel in the liquid channel structure 23, and a region surrounded by the cathode 21, the anode 22, and the liquid channel structure 23 in each slit becomes the liquid channel 23a. there is A groove is formed on the cathode 21 side of the gas channel structure 24, and a portion of the groove surrounded by the gas channel structure 24 and the cathode 21 serves as a gas channel 24a. A groove is formed on the anode 22 side of the gas channel structure 25, and a portion of the groove surrounded by the gas channel structure 25 and the anode 22 serves as a gas channel 25a.

Thus, in the electrochemical reaction device 2, the liquid channel 23a is formed between the cathode 21 and the anode 22, the gas channel 24a is formed between the cathode 21 and the feeder 26, and the anode 22 and the feeder 27 are formed. A gas flow path 25a is formed between them. The feeders 26 and 27 are electrically connected to the reservoir 32 of the power storage device 3 . Moreover, the gas channel structure 24 and the gas channel structure 25 are conductors, so that a voltage can be applied between the cathode 21 and the anode 22 by electric power supplied from the storage section 32 .

The cathode 21 is an electrode that reduces carbon dioxide to produce a carbon compound and reduces water to produce hydrogen. As the cathode 21, any material that can electrochemically reduce carbon dioxide and allows the generated gaseous carbon compound and hydrogen to permeate to the gas flow path 24a can be used. An electrode in which a cathode catalyst layer is formed can be exemplified. The cathode catalyst layer may partially enter the gas diffusion layer. A porous layer denser than the gas diffusion layer may be arranged between the gas diffusion layer and the cathode catalyst layer.

A known catalyst that promotes reduction of carbon dioxide can be used as the cathode catalyst that forms the cathode catalyst layer. Specific examples of cathode catalysts include metals such as gold, silver, copper, platinum, palladium, nickel, cobalt, iron, manganese, titanium, cadmium, zinc, indium, gallium, lead, tin, and alloys and intermetallic compounds thereof. , ruthenium complexes, and rhenium complexes. Among them, copper and palladium are preferable, and copper is more preferable, because the reduction of carbon dioxide is promoted. As the cathode catalyst, one type may be used alone, or two or more types may be used in combination.
As the cathode catalyst, a supported catalyst in which metal particles are supported on a carbon material (carbon particles, carbon nanotubes, graphene, etc.) may be used.

The gas diffusion layer of the cathode 21 is not particularly limited, and examples thereof include carbon paper and carbon cloth.
The method of manufacturing the cathode 21 is not particularly limited, and for example, a method of applying a liquid composition containing a cathode catalyst to the surface of the gas diffusion layer on the side of the liquid flow path 23a and drying it can be exemplified.

Anode 22 is an electrode for oxidizing hydroxide ions to produce oxygen. As the anode 22, any material can be used as long as it can electrochemically oxidize hydroxide ions and allows the generated oxygen to permeate to the gas flow path 25a. can be exemplified.

The anode catalyst forming the anode catalyst layer is not particularly limited, and known anode catalysts can be used. Specifically, for example, metals such as platinum, palladium, and nickel, alloys and intermetallic compounds thereof, manganese oxide, iridium oxide, nickel oxide, cobalt oxide, iron oxide, tin oxide, indium oxide, ruthenium oxide, and lithium oxide. , metal oxides such as lanthanum oxide, and metal complexes such as ruthenium complexes and rhenium complexes. As the anode catalyst, one type may be used alone, or two or more types may be used in combination.

Examples of the gas diffusion layer of the anode 22 include carbon paper and carbon cloth. As the gas diffusion layer, a porous material such as a mesh material, a punching material, a porous material, or a metal fiber sintered material may be used. Examples of the material of the porous body include metals such as titanium, nickel and iron, and alloys thereof (for example, SUS).

Examples of the material of the liquid flow path structure 23 include fluororesins such as polytetrafluoroethylene.
Examples of materials for the gas channel structures 24 and 25 include titanium, metals such as SUS, and carbon.
Examples of materials for the power feeders 26 and 27 include metals such as copper, gold, titanium, SUS, and carbon. As the power feeders 26 and 27, a copper base material having a surface plated with gold or the like may be used.

In the electrochemical reaction device 2, the electrolytic solution is caused to flow through the liquid flow path 23a. The electrolytic solution flowing out from the outlet of the liquid channel 23a is returned to the inlet of the liquid channel 23a and circulated. The carbon dioxide gas G4 supplied from the discharge part 13 is flowed through the gas flow path 24a. By applying a voltage to the cathode 21 and the anode 22, carbon dioxide is electrochemically reduced by the following reaction at the cathode 21 to produce ethylene and hydrogen. A gaseous product C containing ethylene and hydrogen generated at the cathode 21 permeates the gas diffusion layer of the cathode 21 , flows out from the gas channel 24 a, and is sent to the separation section 41 through the gas channel 65 .
CO ₂ +H ₂ O→CO+2OH ⁻
2CO _{+ 8H2O} → _C2H4 + ^8OH- + _2H2O
2H ₂ O→H ₂ +2OH ⁻

Also, the hydroxide ions generated at the cathode 21 move through the electrolyte to the anode 22 and are oxidized by the following reaction to generate oxygen. Oxygen gas D generated at the anode 22 permeates the gas diffusion layer of the anode 22 , flows out from the gas channel 25 a and is sent to the first reactor 42 through the gas channel 66 .
4OH ⁻ →O ₂ +2H ₂ O

The power storage device 3 is a device that supplies power to the electrochemical reaction device 2 .
The conversion unit 31 converts the renewable energy into electrical energy. The conversion unit 31 is not particularly limited, and examples thereof include a wind power generator, a solar power generator, and a geothermal power generator. The number of conversion units 31 included in the power storage device 3 may be one, or two or more.

The storage unit 32 stores the electrical energy converted by the conversion unit 31 . By storing the converted electrical energy in the storage unit 32, electric power can be stably supplied to the electrochemical reaction device 2 even when the conversion unit is not generating electricity. Also, when renewable energy is used, generally voltage fluctuations tend to be large, but by temporarily storing it in the storage unit 32, it is possible to supply power to the electrochemical reaction device 2 at a stable voltage.

The storage unit 32 may be any one that can be charged and discharged, and examples thereof include a nickel-metal hydride battery and a lithium-ion secondary battery. Among them, a nickel-metal hydride battery is preferable from the point of compatibility with the electrolyte used in the electrochemical system.

The ethanolamine synthesis device 4 is a device for synthesizing ethanolamine from ethylene produced by reducing carbon dioxide in the electrochemical reaction device 2 .
In the separation section 41 , ethylene gas E and hydrogen gas F are separated from the gaseous product C supplied from the electrochemical reactor 2 . A part of the separated ethylene gas E is sent to the first reactor 42 through the gas passage 67 and the remainder is sent to the reactor 51 through the gas passage 72 .

The separation unit 41 may be any device as long as it can separate the ethylene gas E and the hydrogen gas F. For example, a known membrane separation device, pressure swing adsorption device, or cryogenic gas separation device can be exemplified. Among them, a membrane separator is preferable from the viewpoint of energy efficiency.

The first reactor 42 is supplied with ethylene gas E through a gas flow path 67 and oxygen gas D through a gas flow path 66 . In the first reactor 42, ethylene is gas-phase oxidized using oxygen gas in the presence of a catalyst to synthesize ethylene oxide. As the catalyst used for gas phase oxidation of ethylene, a known catalyst can be used, and for example, a silver catalyst can be exemplified.
The first reactor 42 is not particularly limited, and a known reactor such as a fixed bed reactor can be used.

The hydrogen gas F separated by the separation section 41 is supplied to the second reactor 43 through the gas flow path 69 . Nitrogen gas is separately supplied to the second reactor 43 . In the second reactor 43, ammonia is synthesized by the reaction of hydrogen and nitrogen in the presence of a catalyst. As a catalyst used for ammonia synthesis, a known catalyst can be used, such as a ruthenium catalyst and an iron catalyst.
The second reactor 43 is not particularly limited, and a known reactor such as a fixed bed reactor can be used.

The ethylene oxide gas H synthesized in the first reactor 42 is supplied to the third reactor 44 through the gas flow path 68 , and the ammonia I synthesized in the second reactor 43 is supplied through the liquid flow path 70 . In the third reactor 44, ethanolamine is synthesized by the reaction of ethylene oxide and ammonia in the presence of a catalyst. As a catalyst used for the reaction of ethylene oxide and ammonia, a known catalyst can be used, for example, a zeolite catalyst.
The third reactor 44 is not particularly limited, and a known reactor such as a fixed bed reactor can be used.

The coal-increase reactor 5 is a device for increasing the amount of ethylene produced by the reduction of carbon dioxide in the electrochemical reactor 2 to increase coal.
Ethylene gas E separated in the separation section 41 from the gaseous product C produced at the cathode 21 of the electrochemical reactor 2 is sent to the reactor 51 through the gas flow path 71 . In the reactor 51, an ethylene polymerization reaction is carried out in the presence of an olefin polymerization catalyst. This makes it possible to produce carbon-rich olefins such as 1-butene, 1-hexene, 1-octene, and the like.

The olefin multimerization catalyst is not particularly limited, and known catalysts used for multimerization reactions can be used, for example, solid acid catalysts using zeolite and transition metal complex compounds can be exemplified.

In the carbon enrichment reactor 5 of this example, the product gas K after the multimerization reaction flowing out of the reactor 51 is sent to the gas-liquid separator 52 through the gas flow path 72 . Olefins having 6 or more carbon atoms are liquid at room temperature. Therefore, for example, when an olefin having 6 or more carbon atoms is used as the target carbon compound, by setting the temperature of the gas-liquid separator 52 to about 30 ° C., the olefin having 6 or more carbon atoms (olefin liquid L) and less than 6 carbon atoms can be easily separated from the olefin (olefin gas M). Also, by increasing the temperature of the gas-liquid separator 52, the number of carbon atoms in the obtained olefin liquid L can be increased.

If the gas G1 supplied to the concentrating section 11 of the recovery device 1 is the air, the separation gas G3 sent from the concentrating section 11 through the gas flow path 75 is used for cooling the produced gas K in the gas-liquid separator 52. You may For example, using a gas-liquid separator 52 equipped with a cooling pipe, the separated gas G3 is passed through the cooling pipe and the generated gas K is passed outside the cooling pipe, and is condensed on the surface of the cooling pipe to form the olefin liquid L. In addition, the olefin gas M separated by the gas-liquid separator 52 contains unreacted components such as ethylene and olefins having a carbon number smaller than that of the target olefin. It can be reused for multimerization reactions.

The ethylene multimerization reaction in the reactor 51 is an exothermic reaction in which the feed material has a higher enthalpy than the product material and the reaction enthalpy is negative. In the manufacturing apparatus 100, the heat of reaction generated in the reactor 51 of the coal-increase reactor 5 is used to heat the heat medium N, and the heat medium N is circulated through the circulation flow path 74 to the release section 13, so that the absorption liquid B is Used for heating.

The carbon enrichment reactor 5 is a reactor for hydrogenation reaction of olefin obtained by enriching ethylene using hydrogen generated in the electrochemical reactor 2, or a reactor for isomerization reaction of olefin or paraffin. may further comprise For example, the hydrogen gas F separated by the separation unit 41 can be used for olefin enrichment.

(Method for producing carbon compound)
A method for producing a carbon compound according to one aspect of the present invention is a method including the following steps (a) to (c).
Step (a): Recover carbon dioxide.
Step (b): Ethylene is obtained by electrochemically reducing the recovered carbon dioxide.
Step (c): Ethylene oxide is obtained by reacting ethylene produced by carbon dioxide reduction with oxygen produced as a by-product, hydrogen produced as a by-product of carbon dioxide reduction is reacted with nitrogen to produce ammonia, and then the oxidation is performed. Ethanolamine is obtained by reacting ethylene with the ammonia.

When using a production apparatus further comprising a carbon-increasing reactor, such as the production apparatus 100, the method for producing a carbon compound further includes the following step (d) in addition to steps (a) to (c). Hereinafter, an example using the manufacturing apparatus 100 described above will be described as a method for manufacturing a carbon compound according to this embodiment.
Step (d): Enrich ethylene produced by carbon dioxide reduction.

In step (a), exhaust gas, air, etc. are supplied as gas G1 to the concentrating section 11, and carbon dioxide is condensed to obtain concentrated gas G2. The carbon dioxide concentration of the concentrated gas G2 can be set as appropriate, and can be, for example, 25 to 85% by volume.

Next, the concentrated gas G2 is supplied from the enrichment part 11 to the absorption part 12, the concentrated gas G2 is brought into contact with the absorbent A, and the carbon dioxide in the concentrated gas G2 is dissolved in the absorbent A and absorbed. The absorbent B that has absorbed carbon dioxide is sent to the release section 13 and heated by heat exchange with the heat medium N supplied from the reactor 51 to release carbon dioxide gas G4. The released carbon dioxide gas G4 is supplied to the electrochemical reactor 2.

In step (b), an electrolytic solution is flowed through the liquid channel 23a of the electrochemical reaction device 2, carbon dioxide gas C is flowed through the gas flow channel 24a, and electric power is supplied from the power storage device 3 to the electrochemical reaction device 2. A voltage is applied between cathode 21 and anode 22 . Then, carbon dioxide is electrochemically reduced at the cathode 21 to produce a gaseous product C containing ethylene and hydrogen. The gaseous product C permeates the gas diffusion layer of the cathode 21 , flows out from the gas flow path 24 a and is sent to the separation section 41 . At the anode 22, hydroxide ions in the electrolyte are oxidized to generate oxygen gas D. As shown in FIG. The oxygen gas D permeates the gas diffusion layer of the anode 22 , flows out from the gas flow path 25 a and is sent to the first reactor 42 .

In step (c), ethylene gas E and hydrogen gas F are separated from the gaseous product C in the separation unit 41, the ethylene gas E is supplied to the first reactor 42, and the hydrogen gas F is supplied to the second reactor 43. supply. Also, the oxygen gas D by-produced at the anode 22 of the electrochemical reaction device 2 is supplied to the first reactor 42 . Then, in the first reactor 42, for example, ethylene is gas-phase oxidized using oxygen gas in the presence of a silver catalyst to synthesize ethylene oxide. The reaction temperature for gas-phase oxidation of ethylene can be appropriately set, and can be, for example, 200 to 300.degree.

Further, in the second reactor, for example, hydrogen and nitrogen are reacted in the presence of a ruthenium catalyst to synthesize ammonia. The reaction temperature for ammonia synthesis can be set as appropriate, and can be, for example, 300 to 400.degree. The reaction pressure for ammonia synthesis can be set appropriately, and can be, for example, 3 to 8 MPa.

Next, the ethylene oxide gas H synthesized in the first reactor 42 and the ammonia I synthesized in the second reactor 43 are supplied to the third reactor 44, and the ethylene oxide and ammonia are reacted in the presence of, for example, a zeolite catalyst. to synthesize ethanolamine J. The reaction temperature for ethanolamine synthesis can be appropriately set, and can be, for example, 20 to 150°C. The reaction pressure for ethanolamine synthesis can be set appropriately, and can be, for example, 5 to 15 MPa.

In the step (d), the ethylene gas E separated in the separation unit 41 is sent to the reactor 51, where it is brought into gas phase contact with an olefin enrichment catalyst to enrich ethylene. This gives an ethylene-enriched olefin. For example, when an olefin having 6 or more carbon atoms is used as the target carbon compound, the product gas K from the reactor 51 is sent to the gas-liquid separator 52 and cooled to about 30°C. Then, the target olefin having 6 or more carbon atoms (eg, 1-hexene) is liquefied, and the olefin having less than 6 carbon atoms remains gaseous, so that the olefin liquid L and the olefin gas M can be easily separated. The number of carbon atoms in the olefin liquid K and the olefin gas M to be gas-liquid separated can be adjusted by the temperature of the gas-liquid separation.

The olefin gas M after the gas-liquid separation can be returned to the reactor 51 and reused for the multi-layering reaction. In this way, when an olefin having a carbon number smaller than that of the target olefin is circulated between the reactor 51 and the gas-liquid separator 52, the raw material gas (a mixed gas of ethylene gas E and olefin gas M) is It is preferable to adjust the contact time between the molecule and the catalyst so that each molecule undergoes a multi-layering reaction once on average. This suppresses an unintentional increase in the carbon number of the olefin produced in the reactor 51 , so that the gas-liquid separator 52 can selectively separate the olefin having the target carbon number (olefin liquid L).

According to such a method, a valuable substance can be efficiently obtained from a renewable carbon source with high selectivity. Therefore, it does not require large-scale refining equipment such as a distillation column, which is required in conventional petrochemicals using the Fischer-Tropsch (FT) synthesis method or the MtG method, and is economically superior overall.

The reaction temperature for the multimerization reaction is preferably 200 to 300°C.
The reaction time of the multimerization reaction, that is, the contact time between the raw material gas and the olefin multimerization catalyst is 0.03 to 0.06 from the viewpoint that excessive multimerization reaction is suppressed and the selectivity of the target carbon compound is improved. Seconds are preferred.

As described above, in the present embodiment, renewable energy is used to synthesize ethylene oxide from ethylene and oxygen produced by the electrochemical reaction of carbon dioxide, and then ethylene oxide and ammonia are reacted to produce ethanolamine. do. As described above, this embodiment is a carbon negative emission technology for obtaining ethanolamine from carbon dioxide, and can reduce the environmental load. In addition, after the synthesis of ethylene oxide, it is also a sustainable technology that can be used in the manufacturing process of conventional industrial products. In addition, in the embodiment using the manufacturing apparatus 100, ethanolamine can be manufactured to regenerate the absorbent while manufacturing olefins and paraffins from carbon dioxide.

[Second embodiment]
(Carbon compound manufacturing equipment)
As shown in FIG. 3, a carbon compound manufacturing apparatus 200 according to one embodiment of the present invention (hereinafter also simply referred to as "manufacturing apparatus 200") includes a recovery device 1, an electrochemical reaction device 2, and a power storage device. 3, an ethylene glycol synthesis device 6, and a carbon enrichment reactor 5. The manufacturing apparatus 200 has the same aspect as the manufacturing apparatus 100 except that the ethylene glycol synthesizing apparatus 6 is provided instead of the ethanolamine synthesizing apparatus 4 . The same parts in FIG. 3 as those in FIG.

The ethylene glycol synthesis apparatus 6 includes a separation section 41 , a first reactor 42 and a fourth reactor 45 . The first reactor 42 and the fourth reactor 45 are connected by a gas flow path 68 . The ethylene glycol synthesizer 6 has the same configuration as the ethanolamine synthesizer 4 except that the second reactor 43 is not provided and the fourth reactor 45 is provided instead of the third reactor 44 .

The ethylene oxide gas H synthesized in the first reactor 42 is supplied to the fourth reactor 45 through a gas flow path 68 . In the fourth reactor 45, ethylene glycol is synthesized by the reaction of ethylene oxide and water in the presence of a catalyst. A known catalyst can be used as a catalyst for the reaction of ethylene oxide and water, and examples thereof include molybdenum, molybdenum trioxide, molybdenum acid, and molybdenum compounds such as ammonium molybdate.
The fourth reactor 45 is not particularly limited, and a known reactor such as a fixed bed reactor can be used.

(Method for producing carbon compound)
A method for producing a carbon compound according to one aspect of the present invention is a method including the following steps (a), (b), and (e).
Step (a): Recover carbon dioxide.
Step (b): Ethylene is obtained by electrochemically reducing the recovered carbon dioxide.
Step (e): Ethylene produced by carbon dioxide reduction is reacted with oxygen by-produced to obtain ethylene oxide, and then the ethylene oxide is reacted with water to obtain ethylene glycol.

When using a manufacturing apparatus further comprising a carbon-increasing reactor, such as the manufacturing apparatus 200, the method for manufacturing a carbon compound includes steps (a), (b), and (e) as well as the above-described step (d). Including further. Hereinafter, an example using the manufacturing apparatus 200 described above will be described as a method for manufacturing a carbon compound according to this embodiment.

Step (a), step (b) and step (d) can be performed in the same manner as step (a), step (b) and step (d) of the method using the manufacturing apparatus 100 .
In step (e), similarly to step (c) of the method using the manufacturing apparatus 100, the first reactor 42 is supplied with ethylene gas E from the separation unit 41 and oxygen gas D from the electrochemical reactor 2. As a result, ethylene oxide is synthesized by gas-phase oxidation of ethylene.

Next, the ethylene oxide gas H synthesized in the first reactor 42 is supplied to the third reactor 44, and ethylene glycol is synthesized by reacting ethylene oxide and water in the presence of, for example, a molybdenum catalyst. The reaction temperature for synthesizing ethylene glycol can be appropriately set, and can be, for example, 50 to 250.degree. The reaction pressure for ethylene glycol synthesis can be set as appropriate, and can be, for example, 0.5 to 2.5 MPa.

As described above, in the present embodiment, renewable energy is used to synthesize ethylene oxide from ethylene and oxygen produced by the electrochemical reaction of carbon dioxide, and then ethylene glycol is produced by reacting ethylene oxide and water. do. As described above, this embodiment is a carbon negative emission technology for obtaining ethylene glycol from carbon dioxide, and can reduce the environmental load. In addition, after the synthesis of ethylene oxide, it is also a sustainable technology that can be used in the manufacturing process of conventional industrial products.

The production apparatus and production method of the carbon compound of the present invention are not limited to those using the production apparatus 100 and the production apparatus 200 described above. The apparatus for producing a carbon compound according to one aspect of the present invention may be an aspect in which the production apparatus 100 or the production apparatus 200 does not include the carbon-increase reaction device. In addition, it is possible to appropriately replace the constituent elements in the above-described embodiment with well-known constituent elements without departing from the spirit of the present invention, and the modifications described above may be combined as appropriate.

DESCRIPTION OF SYMBOLS 100, 200... Carbon compound manufacturing apparatus 1... Recovery apparatus 2... Electrochemical reaction apparatus 3... Power supply storage apparatus 4... Ethanolamine synthesis apparatus 5... Carbon enrichment reaction apparatus 6... Ethylene glycol synthesis apparatus 11 ... Enrichment section, 12 ... Absorption section, 13 ... Emission section, 41 ... Separation section, 42 ... First reactor, 43 ... Second reactor, 44 ... Third reactor, 45 ... Fourth reactor.

Claims (6)

A recovery device for recovering carbon dioxide, an electrochemical reaction device for electrochemically reducing the carbon dioxide recovered by the recovery device, and synthesis of ethanolamine from ethylene produced by the reduction of carbon dioxide in the electrochemical reaction device. an ethanolamine synthesizer for
The ethanolamine synthesizing apparatus includes a first reactor for obtaining ethylene oxide by reacting ethylene produced by carbon dioxide reduction in the electrochemical reactor with oxygen produced as a by-product, and hydrogen produced as a by-product in the electrochemical reactor. with nitrogen to obtain ammonia, a third reactor for obtaining ethanolamine by reacting ethylene oxide obtained in the first reactor with ammonia obtained in the second reactor, A carbon compound manufacturing apparatus. A recovery device for recovering carbon dioxide, an electrochemical reaction device for electrochemically reducing the carbon dioxide recovered by the recovery device, and synthesis of ethylene glycol from ethylene produced by the reduction of carbon dioxide in the electrochemical reaction device. an ethylene glycol synthesizer for
The ethylene glycol synthesis apparatus includes a first reactor for obtaining ethylene oxide by reacting ethylene produced by carbon dioxide reduction in the electrochemical reaction apparatus and by-produced oxygen, and a first reactor for obtaining ethylene oxide by reacting the ethylene oxide with water to produce ethylene. a fourth reactor for obtaining glycol ;
The ethylene glycol synthesizing apparatus is further provided with a separation section for separating ethylene gas and hydrogen gas from the gaseous products obtained in the electrochemical reaction apparatus, and the ethylene gas separated in the separation section is separated into the first reactor. Equipment for manufacturing carbon compounds supplied to The recovery device includes an absorption part that brings carbon dioxide gas into contact with an absorption liquid and absorbs carbon dioxide into the absorption liquid, a release part that heats the absorption liquid that has absorbed carbon dioxide and releases carbon dioxide gas, with
further comprising a carbon enrichment reactor for increasing the amount of ethylene produced in the electrochemical reactor,
3. The apparatus for producing a carbon compound according to claim 1, wherein said release section heats said absorption liquid using heat generated by a multimerization reaction in said carbon-enhancing reactor. recovering carbon dioxide;
a step of electrochemically reducing the recovered carbon dioxide to obtain ethylene;
Ethylene oxide is obtained by reacting ethylene produced by carbon dioxide reduction with oxygen produced as a by-product, hydrogen produced as a by-product by carbon dioxide reduction is reacted with nitrogen to obtain ammonia, and then the ethylene oxide and the ammonia are produced. and a step of reacting to obtain ethanolamine. recovering carbon dioxide;
a step of electrochemically reducing the recovered carbon dioxide to obtain ethylene;
A method for producing a carbon compound, comprising a step of reacting ethylene produced by carbon dioxide reduction with by-produced oxygen to obtain ethylene oxide, and then reacting the ethylene oxide with water to obtain ethylene glycol. 6. The method for producing a carbon compound according to claim 4, further comprising a step of enriching ethylene produced by carbon dioxide reduction.

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