KR20160000940A - System generating synthesis gas and the process of the same - Google Patents

Abstract

The present invention relates to a method for producing carbon monoxide by converting carbon dioxide into carbon monoxide using a solid oxide water electrolytic cell, producing hydrogen through a water gas conversion reactor using the generated carbon monoxide, synthesizing the produced hydrogen through a Fischer- By generating gas, there is an advantage that carbon dioxide emission can be reduced and synthesis gas of energy source can be generated. Also, by circulating the carbon dioxide produced in the water gas conversion reactor to the solid oxide electrolytic cell and circulating the carbon dioxide generated during combustion of the syngas to the solid oxide electrolytic cell, the emission of carbon dioxide can be reduced and the energy utilization efficiency can be improved There is an advantage. Further, by using a material having a double perovskite structure as a fuel electrode of the solid oxide electrolytic cell, there is an advantage that the performance of the solid oxide electrolytic cell can be secured.

Description

[0001] The present invention relates to a synthesis gas producing system and process,

The present invention relates to a synthesis gas producing system and process, and more particularly, to a synthesis gas producing system and process for producing carbon monoxide, hydrogen, and synthesis gas using carbon dioxide.

Carbon dioxide is a molecule in which one carbon atom and two oxygen atoms are bonded, and is a chemically stable molecule. Therefore, it is not easy to synthesize chemicals using carbon dioxide, and carbon dioxide is the most representative greenhouse gas, so it controls emissions from all over the world.

On the other hand, since carbon monoxide is much more reactive than carbon dioxide, a technique for converting carbon dioxide to carbon monoxide and then producing an alternative fuel such as synthetic natural gas or methanol through synthesis is attracting attention. One technique for converting carbon dioxide to carbon monoxide is electrolysis. Since the electrolysis method utilizes heat at a high temperature of 800 ° C or more, there is a problem that a heat source having a high temperature of 800 ° C or more is limited to waste heat discharged from nuclear power generation. Further, since the nickel anode is sensitive to high temperature, there is a problem that coagulation of nickel particles occurs. In addition, nickel exhibits high efficiency at the time of hydrogen generation, but has a problem that the efficiency becomes low at the time of generating carbon monoxide.

U.S. Patent No. 8,591,718

An object of the present invention is to provide a syngas production system and a process capable of increasing the efficiency of generating carbon monoxide and producing hydrogen and synthesis gas using the generated carbon monoxide.

The synthesis gas producing system according to the present invention comprises a solid oxide water-receiving cell for decomposing carbon dioxide to generate carbon monoxide, and a water- A Fischer-Tropsch synthesis reactor for reacting at least a portion of the hydrogen generated in the water gas shift reaction reactor with the remainder of the carbon monoxide generated in the solid oxide water electrolysis cell to produce a synthesis gas and water; And a carbon dioxide supply passage for circulating carbon dioxide generated in the gas conversion reactor to the solid oxide water electrolysis cell.

The synthesis gas production process according to the present invention comprises the steps of: producing carbon monoxide by using carbon dioxide in a solid oxide water-receiving cell; generating hydrogen and carbon dioxide in a water gas conversion reactor using the carbon monoxide; To produce syngas in a Fischer-Tropsch synthesis reactor.

According to another aspect of the present invention, there is provided a process for producing a syngas comprising the steps of: generating carbon monoxide using carbon dioxide in a solid oxide water-receiving cell; generating hydrogen and carbon dioxide in a water gas conversion reactor using the carbon monoxide; And a step of producing synthesis gas in a Fischer-Tropsch synthesis reactor using the carbon monoxide, wherein the carbon dioxide produced in the water gas conversion reactor is supplied to the solid oxide water electrolysis cell, and hydrogen produced in the water gas conversion reactor Supplying the synthesis gas to the Fischer-Tropsch synthesis reactor, supplying carbon dioxide generated during combustion of the synthesis gas to the solid oxide water-dissolving cell, and discharging water generated during combustion of the synthesis gas to the solid oxide- And is supplied to at least one of the water gas shift reaction reactors.

The present invention relates to a method for producing carbon monoxide by converting carbon dioxide into carbon monoxide using a solid oxide water electrolytic cell, producing hydrogen through a water gas conversion reactor using the generated carbon monoxide, synthesizing the produced hydrogen through a Fischer- By generating gas, there is an advantage that carbon dioxide emission can be reduced and synthesis gas of energy source can be generated.

Also, by circulating the carbon dioxide produced in the water gas conversion reactor to the solid oxide electrolytic cell and circulating the carbon dioxide generated during combustion of the syngas to the solid oxide electrolytic cell, the emission of carbon dioxide can be reduced and the energy utilization efficiency can be improved There is an advantage.

Further, by using a material having a double perovskite structure as a fuel electrode of the solid oxide electrolytic cell, there is an advantage that the performance of the solid oxide electrolytic cell can be secured.

1 is a configuration diagram of a system to which a synthesis gas production process according to an embodiment of the present invention is applied.
2 is a schematic view of the solid oxide water-dissipating cell shown in Fig. 2. Fig.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a configuration diagram of a system 10 to which a synthesis gas production process according to an embodiment of the present invention is applied. 2 is a schematic view of the solid oxide water-dissipating cell shown in Fig. 2. Fig.

Referring to FIG. 1, the system 10 for the synthesis gas production process includes a solid oxide water electrolysis cell 20, a water-gas shift reactor 30, , And a Fisher-Tropsch Reactor (30).

The solid oxide electrolytic cell 20 decomposes carbon dioxide (CO ₂ ) to produce carbon monoxide (CO). 2, the solid oxide electrolytic cell 20 includes a cathode 21, an anode 22, an electrolyte 23, and an external power source 24. The cathode 21 is referred to as a fuel electrode because it is in contact with carbon monoxide, and the anode 22 is referred to as an oxygen electrode because it is in contact with oxygen. The electrochemical reaction of the solid oxide electrolytic cell 20 is as shown in Scheme 1. The cathode 21 is a carbon dioxide (CO _2), carbon monoxide (CO) and oxygen ion (O ^2-) and the cathode reaction, the oxygen ions which move through the electrolyte (23) that varies the feed as a (O ^2-) are A positive electrode reaction that changes from the anode 22 to oxygen gas is performed. This reaction is opposite to the reaction principle of a typical fuel cell.

<Reaction Scheme 1>

Cathode reaction: CO ₂ + 2e ^- -> O ^2- + CO

Anode reaction: O ^2- -> 1/2 O ₂ + 2e ^-

That is, when power is applied to the solid oxide electrolytic cell 20 from the external power supply 24, electrons are supplied to the solid oxide electrolytic cell 20. The electrons react with carbon dioxide supplied to the cathode 21 to generate carbon monoxide and oxygen ions. The oxygen ions pass through the electrolyte 23 and are transferred to the anode 22. The oxygen ions transferred to the anode 22 lose electrons and are converted into oxygen gas and discharged. The electrons flow to the external power supply 24. As described above, the solid oxide electrolytic cell 20 electrolyzes carbon dioxide to generate carbon monoxide and oxygen.

The anode 22 may be formed to include various kinds of materials. For example, the anode 22 may comprise LaSrFe-YSZ or may comprise La _0.8 Sr _0.2 Fe-YSZ. In addition, the anode 22 may include a material having a bilayer perovskite structure. The anode 22 may be a PrBa _a Sr _1-a Co _{2 -b} Fe _b O _{5+ d} compound (wherein a is a number of 0 or more and 1 or less, b is a number of 0 or more and 2 or less, lt; / RTI &gt; is 0 or a positive number less than or equal to 1). For example, PrBa _0.5 Sr _0.5 Co _1.5 Fe _0.5 O _{5+ d} compound, NdBa _0.5 Sr _0.5 Co _1.5 Fe _0.5 O _{5+ d} compound, or GdBa _0.5 Sr _0.5 CoFeO _{5+ d} compound.

The electrolyte 23 may be a stabilized zirconia type such as yttria-stabilized zirconia (YSZ) and scandia-stabilized zirconia (ScSZ); Ceria systems doped with rare earth elements such as samaria-doped ceria (SDC), gadolinia-doped ceria (GDC) and the like; Other LSGM ((La, Sr) (Ga, Mg) O ₃ ) system; And the like. In addition, the electrolyte 23 may include strontium or magnesium-doped lanthanum gallate.

The cathode 21 may include a compound of the following formula (1).

&Lt; Formula 1 >

RET ₂ O _{5 + 隆}

Wherein R comprises one or more elements selected from rare earth elements or lanthanides, E comprises one or more elements selected from the group of the alkaline earth metals, and T is selected from the group consisting of one selected from transition metals Or more, O is oxygen, and? Is a positive number of 0 or 1 or less, and is a value that makes the compound of formula (1) electrically neutral. The above 隆 represents interstitial oxygen in the following double layer perovskite structure and the value of 隆 can be determined according to a specific crystal structure. The R may be, for example, yttrium (Y), neodymium (Nd), praseodymium (Pr), scandium (Sc), samarium (Sm), gadolinium (Gd), europium (Eu), terbium ), Or mixtures thereof. The E may include, for example, beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), radium (Ra) The T may be, for example, Mn, Co, Fe, Cu, Cr, Ni, Ti, Nb, . &Lt; / RTI &gt; The materials presented for R, E, and T are illustrative, and the technical idea of the present invention is not limited thereto.

Further, the cathode 21 may include a compound of the following formula (2).

(2)

RBaMn ₂ O _{5 +?}

Wherein R is one or more elements selected from a rare earth group or a lanthanide group, O is oxygen, and? Is a positive number of 0 or 1 or less, the compound of the formula (2) Value. The R may be, for example, yttrium (Y), neodymium (Nd), praseodymium (Pr), scandium (Sc), samarium (Sm), gadolinium (Gd), europium (Eu), terbium ), Or mixtures thereof. The compound of Formula 2 may include, for example, a compound of YBaMn ₂ O _{5 + delta} , a compound of NdBaMn ₂ O _{5 + delta} , or a compound of PrBaMn ₂ O _{5 + delta} .

As described above, the cathode 21 uses a substance (ABCO _{5 + d} ) having a double layer perovskite structure. The material having the double layer perovskite structure can prevent the coarse phenomenon of nickel particles generated when nickel is used as a nickel free electrode material. In addition, the material having a bilayer perovskite structure has high electrical conductivity in an oxidizing atmosphere, and thus is suitable as a fuel electrode material of the solid oxide electrolytic cell 20. In addition, since the material having the double layer perovskite structure does not react with La _0.9 Sr _0.1 Ga _0.8 Mg _0.2 O ₃ (LSGM) electrolyte, it can be used as a fuel electrode material of a middle temperature solid oxide water-soluble cell using LSGM electrolyte.

Reference numeral 70 denotes a carbon monoxide flow path 70 through which the carbon monoxide generated in the solid oxide water receiving cell 20 is discharged. The carbon monoxide flow path 70 includes a first carbon monoxide supply path 71 for supplying at least a portion of the carbon monoxide generated in the solid oxide electrolytic cell 20 to the water gas conversion reactor 30, And a second carbon monoxide supply passage (72) for supplying the carbon monoxide to the Fischer-Tropsch synthesis reactor (40).

The water gas shift reactor (30) reacts at least a portion of the carbon monoxide generated in the solid oxide electrolytic cell (20) with water vapor to produce hydrogen and carbon dioxide. The reaction in the water gas shift reactor (30) is as shown in the following reaction formula (2). The water vapor is supplied with water (H ₂ O) generated upon combustion of a synthesis gas to be described later and converted.

<Reaction Scheme 2>

CO + H ₂ O → H ₂ + CO ₂

The hydrogen produced in the water gas shift reactor 30 is supplied to the Fischer-Tropsch synthesis reactor 40 described later. Reference numeral 80 denotes a flow path for guiding the hydrogen produced in the water gas shift reaction reactor 30 to the Fischer-Tropsch synthesis reactor 40.

The carbon dioxide produced in the water gas shift reactor (30) is supplied to the solid oxide electrolytic cell (20). Reference numeral 50 denotes a carbon dioxide supply passage 50 for guiding the carbon dioxide produced in the water gas shift reactor 30 to the solid oxide water electrolytic cell 20. The carbon dioxide supplying passage 50 includes a first carbon dioxide supplying passage 51 for supplying carbon dioxide generated in the water gas shift converter 30 and a second carbon dioxide supplying passage 51 for supplying carbon dioxide generated in the combustor 100, And a supply flow path 51.

The Fischer-Tropsch synthesis reactor 40 reacts with carbon monoxide and hydrogen to produce synthesis gas and water. At this time, carbon monoxide is supplied to the water gas shift reactor (30) among the carbon monoxide generated in the solid oxide water electrolytic cell (20). The hydrogen uses at least a part of the hydrogen generated in the water gas shift reactor (30). The reaction in the Fischer-Tropsch synthesis reactor (40) is shown in Reaction Scheme 3.

<Reaction Scheme 3>

(2n + 1) H ₂ + nCO → C _n H _{(2n + 2)} + nH ₂ O

Here, the synthesis gas (C _n H _{(2n + 2)} ) includes synthetic natural gas such as methane gas or methanol. The water produced in the Fischer-Tropsch synthesis reactor (40) may be supplied to at least one of the water gas shift reactor (30) and a combustor (100) described below.

The synthesis gas produced in the Fischer-Tropsch synthesis reactor (40) is combusted in the combustor (100) to produce energy. The combustor 100 may include a turbine or the like. The carbon dioxide generated in the combustor 100 during the combustion of the syngas is supplied to the solid oxide charge exchange cell through the second carbon dioxide supply passage 52. Water produced in the combustion of the syngas in the combustor 100 is supplied to at least one of the solid oxide water receiving cell 20 and the water gas conversion reactor 30. Reference numeral 60 denotes a water supply passage 60 for guiding the water produced in the combustor 100 to the solid oxide water electrolytic cell 20 and the water gas conversion reactor 30. The water supply passage 60 includes a first water supply passage 61 for supplying the water to the solid oxide water electrolytic cell 20 and a second water supply passage 61 for supplying the water to the water- (62).

The process of the synthesis gas generating system having the above-described structure will be described below.

In the solid oxide electrolytic cell 20, carbon monoxide is produced using carbon dioxide. At this time, the carbon dioxide produced in the water gas shift reactor (30) and the carbon dioxide produced in the combustor (100) are used as the carbon dioxide. Therefore, the amount of carbon dioxide emission can be reduced and the occurrence of environmental pollution problems can be reduced. If the heat source is sufficient, the conversion efficiency of converting the carbon dioxide into carbon monoxide reaches about 100%.

The carbon monoxide generated in the solid oxide electrolytic cell 20 is supplied to the water gas shift reactor 30 and the Fischer-Tropsch synthesis reactor 40.

In the water gas shift reactor (30), hydrogen and carbon dioxide are produced using the carbon monoxide. Here, since the generated carbon dioxide is supplied back to the solid oxide electrolytic cell 20, the carbon dioxide is not discharged to the outside. Further, the generated hydrogen is supplied to the Fischer-Tropsch synthesis reactor (40) and used for the reaction in the Fischer-Tropsch synthesis reactor (40).

In the Fischer-Tropsch synthesis reactor (40), synthesis gas is produced using the hydrogen and the carbon monoxide. The syngas produced here is burned and used to produce energy.

The Fischer-Tropsch synthesis reactor 40 has a synthesis gas (CH ₄ ) selectivity of about 10 to 8% when the carbon monoxide conversion is about 83.1% to 90%. This is data on experimental results when FeCu / MnO ₂ is used as the catalyst and the temperature is 533K to 573K. Therefore, when the molar concentration of carbon dioxide is assumed to be 1, the molar concentration of carbon monoxide is 1, and when the carbon monoxide conversion rate and the synthesis rate of the synthesis gas (CH ₄ ) are calculated, the carbon monoxide conversion rate is 83.1% The synthesis yield of the gas (CH ₄ ) is about 8.31%, and the synthesis yield of the synthesis gas (CH ₄ ) is about 7.2% when the carbon monoxide conversion rate is 90% and the synthesis gas generation rate is 8%. Accordingly, about 0.072 to 0.083 moles of the synthesis gas (CH ₄ ) may be produced.

As described above, by using the solid oxide electrolytic cell 20 to convert carbon dioxide to carbon monoxide, generate hydrogen using the generated carbon monoxide, and generate synthetic gas using the generated hydrogen and carbon monoxide, There is an advantage that it can be used as an energy source.

In addition, the generated syngas can be converted into fuel and used for energy production, and the generated carbon dioxide can be recycled back to the solid oxide receiving cell 20. Also, the carbon dioxide produced in the water gas shift reactor 30 may be recycled to the solid oxide electrolytic cell 20.

Further, by using a material having a double perovskite structure as a fuel electrode of the solid oxide electrolytic cell 20, there is an advantage that the performance of the solid oxide electrolytic cell 20 can be secured.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

20: Solid oxide water electrolysis cell 30: Water gas conversion reactor
40: Fischer-Tropsch synthesis reactor

Claims (14)

A solid oxide water-receiving cell for decomposing carbon dioxide to generate carbon monoxide;
A water gas shift reactor for reacting at least a portion of the carbon monoxide generated in the solid oxide water electrolysis cell with water vapor to produce hydrogen and carbon dioxide;
A Fischer-Tropsch synthesis reactor for reacting the remainder of the carbon monoxide generated in the solid oxide water electrolytic cell with at least a part of the hydrogen produced in the water gas conversion reactor to produce a synthesis gas and water;
And a carbon dioxide supply channel for circulating carbon dioxide generated in the water gas shift reaction reactor to the solid oxide electrolytic cell to supply the carbon dioxide gas. The method according to claim 1,
And a flow path for circulating carbon dioxide generated during the combustion of the syngas generated in the above-described manner to the solid oxide water-receiving cell. The method according to claim 1,
And a flow path for circulating the water generated in the combustion of the syngas generated in the above-described process to at least one of the solid oxide water receiving cell and the water gas conversion reactor. The method according to claim 1,
Wherein the solid oxide water-dissolving cell comprises a cathode decomposing carbon dioxide to produce carbon monoxide, wherein the cathode comprises a compound of the following formula (1).
&Lt; Formula 1 >
RET ₂ O _{5 + 隆}
Wherein R comprises one or more elements selected from rare earth elements or lanthanides, E comprises one or more elements selected from the group of alkaline earth metals, and T is selected from the group consisting of one selected from transition metals Or more, O is oxygen, and? Is a positive number of 0 or 1 or less, and is a value that makes the compound of formula (1) electrically neutral. The method of claim 4,
In Formula 1,
The R may be at least one selected from the group consisting of Y, Ne, Pr, Sc, Sm, Gd, Eu, Ti, Er, , &Lt; / RTI &gt;
Wherein E is at least one selected from the group consisting of beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), radium (Ra)
Wherein T is at least one element selected from the group consisting of Mn, Co, Fe, Cu, Cr, Ni, Ti, Nb, , A syngas production system. The method of claim 4,
Wherein the compound of Formula 1 has a bilayer perovskite structure. The method of claim 4,
Wherein the cathode comprises a compound of formula (2).
(2)
RBaMn ₂ O _{5 +?}
Wherein R is one or more elements selected from a rare earth group or a lanthanide group, O is oxygen, and? Is a positive number of 0 or 1 or less, the compound of the formula (2) Value. The method of claim 7,
Wherein the compound of formula 2 comprises a compound of YBaMn ₂ O _{5 + delta} , a compound of NdBaMn ₂ O _{5 + delta} , or a compound of PrBaMn ₂ O _{5 + delta} . Generating carbon monoxide in the solid oxide water-electrolytic cell using carbon dioxide;
Generating hydrogen and carbon dioxide in the water gas shift reactor using the carbon monoxide;
And producing synthetic gas in the Fischer-Tropsch synthesis reactor using the hydrogen and the carbon monoxide. The method of claim 9,
A synthesis gas producing step of circulating the carbon dioxide produced in the water gas shift reactor to the solid oxide water-dissolving cell to supply it. The method of claim 9,
A synthesis gas producing step of supplying the hydrogen produced in the water gas conversion reactor to the Fischer-Tropsch synthesis reactor. The method of claim 9,
A synthesis gas producing step of circulating carbon dioxide generated during combustion of the syngas to the solid oxide water-dissolving cell to supply it. The method of claim 9,
And supplying water generated during combustion of the syngas to at least one of the solid oxide water receiving cell and the water gas conversion reactor. Generating carbon monoxide in the solid oxide water-electrolytic cell using carbon dioxide;
Generating hydrogen and carbon dioxide in the water gas shift reactor using the carbon monoxide;
And producing synthesis gas in the Fischer-Tropsch synthesis reactor using the hydrogen and the carbon monoxide,
The carbon dioxide produced in the water gas conversion reactor is supplied to the solid oxide water electrolysis cell, and the hydrogen produced in the water gas conversion reactor is supplied to the Fischer-Tropsch synthesis reactor,
A synthesis gas supply unit for supplying carbon dioxide generated during combustion of the syngas to the solid oxide water electrolytic cell and supplying water generated during combustion of the synthesis gas to at least one of the solid oxide water- Production process.

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