WO2021091182A1 - Formic acid manufacturing process and manufacturing apparatus using synthetic gas - Google Patents

Abstract

The present invention relates to a process and apparatus for manufacturing formic acid from a synthetic gas and, specifically, to a process and apparatus for manufacturing formic acid, in which: a mixed gas (mixture) of hydrogen prepared by a water-gas shift reaction of a synthetic gas and carbon dioxide, and an amine-based compound as a reaction medium are used; and an amine adduct which has captured carbon dioxide from an exhaust gas discharged by a combustion is fed to a reactor to manufacture formic acid.

Description

Manufacturing process and manufacturing equipment of formic acid using syngas

The present invention relates to a process and apparatus for producing formic acid using a mixture of hydrogen and carbon dioxide produced by a water gas conversion reaction of syngas.

Formic acid is a compound that can be used for many purposes. For example, it can be used as an auxiliary agent for acidification, disinfectant or textile in the manufacture of animal feed, as an auxiliary agent in the leather industry, as a reactant for deicing of aircraft or runways, and the like.

Conventionally, one of the processes for commercially preparing formic acid was to carbonylate synthesized methanol to prepare methyl formate, and then hydrate it. In this process, in order to prepare formic acid using methanol, a total of three steps of a synthesis process of methanol, a carbonylation process of methanol, and a hydration process of methyl formate are required.

Accordingly, many studies have been conducted on a process capable of producing formic acid in only one step by using a hydrogenation reaction of carbon dioxide. As an example, there is a process of producing formic acid by reacting carbon dioxide and hydrogen in a high-pressure stirred reactor containing a homogeneous catalyst and an amine. In the production process of formic acid through the hydrogenation of carbon dioxide, a catalyst having a high activity for hydrogenation reaction may also exhibit a large activity for decomposition reaction of formic acid. Therefore, in order to suppress the decomposition of formic acid and obtain a high yield of formic acid, it is very important to recover the catalyst.

In 1994, Noyori and Jessop et al implemented a process of producing formic acid by carrying out a hydrogenation reaction on a homogeneous catalyst under supercritical carbon dioxide conditions. Since then, a number of Ru-based and Ir-based homogeneous catalysts have been developed, and as a result, catalysts having high activity up to a level of hundreds of thousands of TON (turnover numbers) have been developed. Nevertheless, the hydrogenation reaction of carbon dioxide has not been commercialized due to the problem of development of a reaction system and process for recovering a homogeneous catalyst.

To solve this problem, US 20120157711A1 uses an amine having 6 or more carbons per molecule as a catalyst to recover the catalyst through phase separation into a solvent layer in which a homogeneous catalyst is well dissolved and a solvent layer in which formic acid is mainly dissolved. , It has been disclosed that an alcohol solvent is separately added.

However, complete recovery of the catalyst was not possible only by using an amine as a catalyst and adding an alcohol solvent. Accordingly, an attempt was made to obtain formic acid through hydrogenation using a stirred reactor under heterogeneous catalytic conditions such as Ag catalyst, but a problem of low reaction activity occurred under pressure conditions of 180 atmospheres or higher (Angew. Chem. 123 (2011) 12759). . In addition, when carbon dioxide is directly hydrogenated, excessive costs are consumed for capturing carbon dioxide and producing hydrogen, and the amount of carbon dioxide generated during hydrogen production is 12.13 kg CO ₂ /H ₂ (J. Clean Prod. 85 (2014) 151-163) As it is excessive, it is difficult to secure economic efficiency, and there is a problem in that the effect of reducing carbon dioxide is inferior.

In the present invention, a mixture of hydrogen and carbon dioxide is prepared by a water gas reaction of synthesis gas, introduced into a formate generating reactor without a separate separation process, and additionally required carbon dioxide is collected using an amine, which is a reaction medium, and is directly carbon dioxide. By producing formic acid by using in the hydrogenation reaction of, it is intended to solve the problem that excessive costs are consumed in the production of formic acid, and the effect of reducing carbon dioxide is inferior. Also, by using a heterogeneous catalyst, it is intended to solve the problem of a homogeneous catalyst.

In order to solve the above problems, the present invention provides a process for converting carbon monoxide contained in the synthesis gas into carbon dioxide and hydrogen by supplying syngas to a water gas conversion unit together with a required amount of water; A step of supplying a mixed gas containing carbon dioxide and hydrogen converted by the water gas conversion unit to a formate generation unit equipped with a formic acid production catalyst to generate formate; And a step of separating formic acid by supplying the formic acid salt to a formic acid separation unit, wherein the synthesis gas is at least one selected from the group consisting of hydrocarbons having 1 to 5 carbon atoms, coal, biomass, biogas, and steel mill by-product gas. It provides a manufacturing process of formic acid that is derived from.

In addition, the present invention, a water gas conversion unit for converting carbon monoxide contained in the synthesis gas into carbon dioxide and hydrogen by the water gas reaction of the synthesis gas; A formate generating unit for generating formate by reacting the mixed gas containing hydrogen and carbon dioxide with an amine-based compound in the presence of a catalyst; And a formic acid separation unit for separating formic acid from the formic acid salt, wherein the synthesis gas is derived from at least one selected from the group consisting of hydrocarbons having 1 to 5 carbon atoms, coal, biomass, biogas, and steelworks by-product gas. It provides an apparatus for producing formic acid.

In the present invention, since synthesis gas is used as a reaction raw material, it is not necessary to use purified carbon dioxide and hydrogen as a reaction raw material for the hydrogenation of carbon dioxide, and thus economical efficiency can be improved compared to a conventional manufacturing process of formic acid by hydrogenation of carbon dioxide. have. In addition, according to the present invention, since the formate generation unit filled with a heterogeneous catalyst is used, the product does not contain a catalyst component, a separate catalyst recovery system is not required, and catalyst particles are prevented from being crushed.

The technical effects of the present invention are not limited to those mentioned above, and other technical effects that are not mentioned will be clearly understood by those skilled in the art from the description of specific details for carrying out the invention.

1 is a flowchart illustrating a manufacturing process and a manufacturing apparatus for formic acid according to the present invention.

2 is a reference diagram for explaining the analysis result of the catalyst prepared in Example 1 of the present invention.

3 is a flow chart showing the manufacturing process of the catalyst in Example 2 of the present invention.

4 is a reference diagram for explaining the analysis result of the catalyst prepared in Example 4 of the present invention.

5 is a reference diagram for explaining the analysis result of the catalyst prepared in Example 6 of the present invention.

6 is a schematic diagram showing a fixed bed reactor used in the manufacturing process of formic acid according to the present invention.

7 is a reference diagram for explaining the productivity results of formate in Example 15 of the present invention.

8 is a schematic diagram showing a fluidized bed reactor used in the manufacturing process of formic acid according to the present invention.

9 is a flowchart illustrating a manufacturing process of formic acid according to Example 17 of the present invention.

Terms and words used in the description and claims of the present invention should not be construed as being limited to their usual or dictionary meanings, and the inventors appropriately explain the concept of terms in order to explain their own invention in the best way. Based on the principle that it can be defined, it should be interpreted as a meaning and concept consistent with the technical idea of the present invention.

The present invention converts carbon monoxide contained in the synthesis gas into carbon dioxide and hydrogen by a water gas reaction of the synthesis gas and supplies it to a reactor (for example, a formate generation reactor) without a separate separation process, and is also included in the combustion flue gas. The present invention relates to a process and apparatus for producing formic acid through a process of collecting carbon dioxide as an amine compound as a reaction medium and supplying it to a reactor, and then hydrogenating carbon dioxide in a reactor containing a heterogeneous catalyst, separating and purifying it. .

Specifically, the manufacturing process of formic acid according to the present invention includes a process of converting carbon monoxide contained in synthesis gas into carbon dioxide and hydrogen (hereinafter referred to as'A-1 process'); The process of producing formate (hereinafter referred to as'A-2 process'); And a process of separating formic acid (hereinafter referred to as'A-3 process'). The manufacturing process of formic acid according to the present invention may further include a process of generating a carbonic acid-amine adduct compound (hereinafter referred to as'A-4 process'), if necessary. In addition, the manufacturing process of formic acid according to the present invention may further include a process of gas-liquid separating a product containing formic acid salt (hereinafter referred to as'A-5 process'), if necessary.

The apparatus for producing formic acid according to the present invention may include a water gas conversion unit 100, a formate generation unit 200, and a formic acid separation unit 300. The apparatus for producing formic acid according to the present invention may further include a carbon dioxide collecting unit 400 as necessary. In addition, the apparatus for producing formic acid according to the present invention may further include a gas-liquid separation unit 500.

The manufacturing process and manufacturing apparatus of formic acid according to the present invention will be described in detail with reference to FIG. 1 as follows.

The A-1 process is a process of generating carbon dioxide and hydrogen from carbon monoxide and water contained in the synthesis gas as a reaction raw material, and supplying the synthesis gas to the water gas conversion unit 100 to convert carbon monoxide contained in the synthesis gas into hydrogen and carbon dioxide. It can be converted into a process of generating carbon dioxide and hydrogen. Specifically, the A-1 process may include a water gas reaction as shown in Reaction Formula 1 below.

[Scheme 1]

CO + H ₂ O → CO ₂ + H ₂

The water gas reaction thermodynamically may proceed to a completion reaction as the temperature decreases, and the conversion rate of carbon monoxide may decrease as the temperature increases. This water gas reaction may be carried out in one step, but it may be carried out in two steps to increase the reaction efficiency. Specifically, the water gas reaction may be carried out through a high-temperature water gas reaction in which the reaction is performed at a high temperature of 300 degrees or higher and a low-temperature water gas reaction in which the reaction is performed at a temperature of 300 degrees or less.

The high-temperature water gas reaction may be performed under conditions of a molar ratio of water to CO of 10:1 to 1:1, a reaction temperature of 300 to 500 degrees, and a reaction pressure of 1 to 50 atmospheres. In addition, a mixed oxide-based catalyst such as Fe, Cr, and Zn may be used for the high-temperature water gas reaction.

The low-temperature water gas reaction may be performed under conditions of a molar ratio of water to CO of 10:1 to 1:1, a reaction temperature of 100 to 300 degrees and a reaction pressure of 1 to 50 atmospheres. In addition, a catalyst such as _{Cu, ZnO, Al 2} O ₃ may be used for the low-temperature water gas reaction. At this time, Zr and/or Ga oxide may be added to the catalyst.

Syngas, which is the stream (1) supplied to the water gas conversion unit 100 in the A-1 process, is at least one selected from the group consisting of hydrocarbons having 1 to 5 carbon atoms, coal, biomass, biogas, and steel mill by-product gas. It may be derived from.

More specifically, the synthesis gas may include a reactant obtained by reforming a hydrocarbon having 1 to 5 carbon atoms such as methane, ethane, propane, butane or pentane. In addition, the synthesis gas may include a reactant obtained by reforming or gasifying coal or biomass. In addition, the synthesis gas may include a reactant obtained by reforming biogas or by-product gas from a steel mill. The reforming reaction and gasification reaction may be performed by a conventionally known method.

The mixed gas generated through the A-1 process may be supplied to the A-2 process as a stream 2 containing carbon dioxide and hydrogen.

Since the mixed gas obtained through the A-1 process is directly supplied to the formate generation unit 200 to be described later without a separate separation process, the hydrogen production process and carbon dioxide that were performed to produce hydrogen and carbon dioxide, which are raw materials for producing formic acid. The collection and purification process of is omitted, so that the efficiency (economy) of the manufacturing process of formic acid can be improved compared to the conventional one.

The A-4 process is a process of generating a carbonic acid-amine addition compound, and may include a process of generating a carbonic acid-amine addition compound by supplying combustion exhaust gas and an amine-based compound to the carbon dioxide collecting unit 400. This A-4 process may be selectively performed as needed. That is, in the A-4 process, the molar ratio (b/a) of carbon dioxide (a) and hydrogen (b) contained in the mixed gas supplied to the formate generation unit 200 is lower than 2.0, so that carbon dioxide is generated in the formate generation reaction. It is performed when insufficient, and may include a reaction of absorption of carbon dioxide by an amine-based compound as shown in Scheme 2 below. At this time, carbon dioxide may be physically absorbed by some solvents.

[Scheme 2]

_{a CO 2 + b NR 1 R} 2 R 3 + H 2 O → b NR 1 R 2 R 3 H +: c HCO 3 -

Specifically, in the A-4 process, the combustion exhaust gas (stream 8) and the amine compound are supplied to the carbon dioxide collecting unit 400, and the carbon dioxide contained in the combustion exhaust gas is absorbed by the amine compound, which is a reaction medium, and NR ₁ R ₂ Carbonic acid-amine adducts such as R ₃ H ⁺ :HCO ₃ ^{-and the like may be produced.} The carbonate-amine adduct is specifically ammonium bicarbonate ((HNR ₁ R ₂ R ₃ ) ⁺ (HCO ₃ ) ^- ), or ammonium carbonate (HNR ₁ R ₂ R ₃ ) ₂ ²⁺ (CO ₃ ) ^2- ) It may contain an ammonium salt such as. In addition, the carbonate-amine addition compound may take the form of an aqueous solution.

Here, when trialkylamine is used as the amine compound, the solubility in water is low, so that the trialkylamine and water may undergo phase separation between liquids in the hydrogenation reaction of carbon dioxide. When the phase separation occurs in this way, the reaction efficiency in the hydrogenation process of carbon dioxide may be lowered.

However, since the carbonic-amine adduct is an ammonium _{salt such as ammonium bicarbonate, (HNR 1} R ₂ R ₃ ) ⁺ (HCO ₃ ) ^- ) as the main component, the solubility in water is high, so that water in the hydrogenation reaction of carbon dioxide Over-phase separation can be minimized, and thus, the present invention can increase the reaction efficiency in the hydrogenation process of carbon dioxide. The molar ratio (c/b) of HCO ₃ ^- _{to NR 1} R ₂ R ₃ H ⁺ in the carbonate-amine adduct may be 0.1 to 1.0.

The amine-based compound reacting with the combustion exhaust gas may be a compound represented by the following formula (1).

[Formula 1]

NR ₁ R ₂ R ₃

In Formula 1,

R ₁ to R ₃ are the same as or different from each other, and each independently selected from the group consisting of hydrogen, an alkyl group having 1 to 6 carbon atoms, and a cycloalkyl group having 3 to 10 carbon atoms or bonded to each other (e.g., R ₁ and R ₂ Bond, a bond of R ₂ and R ₃ , or a bond of R ₂ and R ₃ ) to form an aliphatic ring or an aromatic ring, and _{the alkyl group and cycloalkyl group of R 1} to R ₃ are each independently an alkyl group having 1 to 10 carbon atoms And it may be unsubstituted or substituted with one or more substituents selected from the group consisting of an aryl group having 6 to 10 carbon atoms.

Here, _{the total number of carbon atoms contained in R 1} to R ₃ may be 12 or less, and specifically, R ₁ , R ₂ and R ₃ may each independently be an alkyl group having 2 or 3 carbon atoms.

The alkyl group may be linear or branched, and specifically, may be a methyl group, an ethyl group, a propyl group, a butyl group, or the like. Specifically, the cycloalkyl group may be a cyclopropyl group, a cyclobutyl group, a cyclohexyl group, and the like. The aromatic ring may be an aromatic ring containing or not including a hetero atom such as N, O, or S. The aryl group may be a phenyl group, a naphthyl group, or the like.

Specifically, the amine-based compound represented by Formula 1 is trimethylamine, triethylamine, tripentylamine, tripropylamine, tributylamine, trihexylamine ( trihexylamine), N,N-dimethylbutylamine, dimethylcyclohexylamine, dimethylphenethylamine, and isoamylamine have.

In addition, the amine-based compound reacting with the combustion exhaust gas may be a dialkyl piperazine (N,N-dialkyl piperazine) such as dimethyl piperazine (N,N-dimethyl piperazine) and diethyl piperazine (N,N-diethyl piperazine); Morpholine; N-alkyl morpholine such as N-methyl morpholine, N-ethyl morpholine, N-propyl morpholine, N-butyl morpholine, etc. ; Alkylpiperidine, such as methylpiperidine, ethylpiperidine, propylpiperidine, and butylpipeirdine; And at least one selected from the group consisting of alkylpyrrolidines such as methylpyrrolidine, ethylpyrrolidine, propylpyrrolidine, butylpyrrolidine, etc. I can. Specifically, the amine-based compound may be dialkylpiperazine, alkylpiperidine, alkylpyrrolidine, or alkylmorpholine, which does not require a separate phase separation process due to its high solubility in water.

In the step A-4, the absorption reaction of carbon dioxide may be carried out at a reaction temperature of 10 to 100 degrees (specifically, 20 to 80 degrees) and a reaction pressure of 1 to 50 atm (specifically, 1 to 20 atm).

The product including the carbonic acid-amine adduct produced through the A-4 process may be discharged from the carbon dioxide collecting unit 400 as a stream 7 and supplied to the formate generating unit 200. Specifically, the stream 7 may contain a carbonic acid-amine adduct, an amine-based compound, and carbon dioxide. In addition, stream (7) may contain free amines or mixtures of free carbonic acids with carbonic-amine adducts.

In the process A-4, the carbon dioxide collecting unit 400 may include a carbon dioxide absorption tower in which a carbon dioxide absorption reaction occurs from combustion exhaust gas.

The A-2 process is a process of generating formate, which is a formic acid precursor, and a mixed gas containing carbon dioxide and hydrogen generated by the water gas conversion unit 100 is transferred to the formate generating unit 200 provided with a catalyst. It can be made in the process of producing formate by supplying. Specifically, in the A-2 process, formate (amine-formic acid adduct) is generated through the reaction of carbon dioxide, an amine compound, and hydrogen, and may include a hydrogenation reaction of carbon dioxide as shown in Scheme 3 below.

[Scheme 3]

_{a CO 2 + b H 2 +} c H 2 O + d NR 1 R 2 R 3 H +: xHCO 3 - → d NR 1 R 2 R 3 H +: eHCOO -

In Scheme 3, water (H ₂ O) may be derived from the formate generated in the formate generating unit 200 (recovered through gas-liquid separation of the formate), and supplied to the formate generating unit 200 as an auxiliary solvent. It can mean the case of becoming. In addition, instead of water, auxiliary amines (e.g., n-methylpyrrolidone and n-butylimidazole) derived from the formic acid separation unit 300 may be supplied as auxiliary solvents, or a mixture of auxiliary amines and water may be supplied as auxiliary solvents. have. The auxiliary amine is an aproctic amine, N-methylpyrrolidone, N-formyl morpholine, N-methylacetamide , N,N-dimethylacetamide, NN-diethylacetamide, N-ethylacetamide, N-butylimidazole , N-methylimidazole and N-ethylimidazole may be one or more selected from the group consisting of (N-ethylimidazole).

In Scheme 3, carbon dioxide (CO ₂ ) may be dissolved in a solution. In addition, carbon dioxide (CO ₂ ) is carbon dioxide (CO 2) converted in the water gas conversion unit 100, _{or a separate carbon dioxide (CO 2} ) with the mixed gas supplied to the formate generation unit 200 (stream (2))) ₂ ) may have been additionally supplied. The separate carbon dioxide (CO ₂ ) may be supplied from the carbon dioxide collecting unit 400 or through a carbon dioxide supply line (not shown) separately provided in the formate generating unit 200.

The in Scheme 3, acid-amine addition compound _{(d NR 1 R 2 R 3} H +: xHCO 3 -) is herein to mean that the supply in the above-described carbon dioxide absorption portion 400, a carbon dioxide-amine instead of the amine addition compound based The compound may directly participate in the reaction. The amine-based compound may be supplied from the carbon dioxide collecting unit 400 or may be supplied to the formate generating unit 200 through a separate supply line. Here, since the amine-based compound is the same component as the amine-based compound described in step A-4, a description thereof will be omitted. This amine-based compound may be separated and discharged from the formic acid separation unit 300 as a stream 6 after the formate generation reaction, and may be supplied (circulated) to the carbon dioxide collection unit 400.

The molar ratio (e/d) of _{HCO 2} ^- _{to NR 1} R ₂ R ₃ H ⁺ in the formate (amine-formic acid adducted compound) generated through Scheme 3 may be 0.1 to 2.5.

In general, the production reaction of formic acid by hydrogenation of carbon dioxide is a nonspontaneous reaction, and ΔG (Gibs-free energy change) may have a positive value. However, when an amine-based compound (NR ₁ R ₂ R _{3 in} Chemical Formula 1) is used as in the present invention, ΔG (Gibs-free energy change) of the hydrogenation reaction of carbon dioxide may have a negative value, and thus conventional carbon dioxide It can overcome the thermodynamic limitation of hydrogenation reaction.

Meanwhile, the molar ratio of hydrogen to carbon dioxide contained in the feed (stream (2) + (7) + (4) in Fig. 1) introduced into the formate generation unit 200 as an unreacted circulating gas may be 0.1 to 10.0. have. Specifically, the molar ratio of hydrogen to carbon dioxide may be 0.5 to 3.0, more specifically 0.5 to 1.5. More specifically, the molar ratio of hydrogen to carbon dioxide may be 0.8 to 1.2. When the molar ratio of hydrogen to carbon dioxide is less than 0.1, the conversion rate of carbon dioxide is very low, so that the yield of formic acid to carbon dioxide can be reduced. Is increased, the size of the reactor increases, the conversion production rate of carbon dioxide decreases, and the catalyst is reduced and can be easily deactivated. Specifically, when the molar ratio of hydrogen to carbon dioxide is 1.0 ± 0.2, the amount of unreacted circulating gas is minimized, so that an optimum reaction condition can be obtained.

Here, the carbon dioxide supplied to the formate generating unit 200 may be simply absorbed in a solution, dissolved in water, or combined with an amine-based compound. Therefore, the molar ratio of hydrogen to carbon dioxide can be determined by Equation 1 below.

[Equation 1]

In the A-2 process, the hydrogenation reaction of carbon dioxide may be carried out at a reaction temperature of 30 to 200 degrees (specifically, 40 to 150 degrees) and a reaction pressure of 20 to 200 atm (specifically, 30 to 150 atm). When the reaction temperature is less than 30 degrees, the catalytic activity may be lowered, and when the reaction temperature exceeds 200 degrees, the catalyst may be reduced and deactivated. In addition, when the reaction pressure is less than 20 atmospheres, the catalytic activity may be lowered, and when the reaction pressure exceeds 200 atmospheres, a lot of energy is consumed for the reaction, and the process efficiency may decrease.

In the step A-2, the catalyst provided in the formate generating unit 200 may be supported on a porous carrier including at least one of nitrogen and phosphorus as an active metal.

The active metal may include at least one selected from the group consisting of iridium (Ir), ruthenium (Ru), palladium (Pd), gold (Au), iron (Fe), and cobalt (Co). Such an active metal may be derived from a compound containing an active metal.

The compound containing the active metal may be in a form in which an active metal and a salt thereof are combined. The salt of the active metal may be a chlorine salt, acetate, acetylacetonate, nitrate, hydroxide, sulfate, or sulfide. .

In addition, the compound containing the active metal may be an oxide, an oxide in which they are hydrated, an oxide in which they are mixed, a reduced metal, or a metal in which they are mixed.

The porous carrier containing at least one of nitrogen and phosphorus is porous organic frameworks (POFs), covalent organic frameworks (COFs), and covalent triazine frameworks (CTFs). , Porous aromatic frameworks (porous aromatic frameworks, PAFs) and porous organic polymers (porous organic polymer, POP) may include one or more selected from the group consisting of. Such a porous carrier may include a triazine structure or a heptazine structure.

In addition, the porous carrier containing at least one of nitrogen and phosphorus may be a pyridine bonded nitrogen (pyridinic-N), a pyrrole bonded nitrogen (pyrrolic-N), a pyrazole bonded nitrogen (pyrazole-N) and a graphite bonded nitrogen. It may include one or more selected from the group consisting of (graphitic-N).

In addition, the porous carrier containing at least one of nitrogen and phosphorus (specifically, a porous carrier containing nitrogen or phosphorus in the skeletal structure) includes at least one selected from the group consisting of titania, alumina, gallia, zirconia, and silica. can do.

The catalyst provided in the formate generation unit 200 may exhibit high catalytic activity due to nitrogen and/or phosphorus contained in the lattice of the porous carrier, and may exhibit improved catalytic stability.

The product including formate generated through the A-2 process may be discharged from the formate generating unit 200 as a stream 3 and supplied to the formic acid separating unit 300. Specifically, the stream 3 may contain formate (amine-formic acid adduct), carbon dioxide, hydrogen, and water. In addition, the stream 3 may contain a mixture of free amine or free formic acid together with formate.

In the process A-2, the formate generating unit 200 may include a formate generating reactor for generating formate. The formate generating reactor may include at least one selected from the group consisting of a stirred reactor, a fixed bed reactor, and a fluidized bed reactor.

The A-5 process is a process of gas-liquid separating a product containing formate, and may be performed by supplying a product containing formate to the gas-liquid separation unit 500 to separate carbon dioxide and hydrogen. This A-5 process may be selectively performed as needed.

Through the A-5 process, the product containing formate may be separated into gas and liquid (or liquid + solid) components. The gaseous components separated from the formate-containing product may include carbon dioxide (unreacted carbon dioxide) and hydrogen, which may be supplied back to the formate generating unit 200 as a stream 4. In addition, the liquid or liquid + solid component separated from the formate-containing product may include formate (formic acid-amine adduct), which may be supplied to the formic acid separation unit 300 as a stream 5.

In the A-5 process, gas-liquid separation may be performed at a temperature of 25 to 150 degrees (specifically, 40 to 100 degrees). In addition, the pressure may be the same as the reaction pressure of the carbon dioxide hydrogenation reaction.

In the process A-5, the gas-liquid separator 200 may include a gas-liquid separator.

The A-3 process is a process of separating formic acid from formic acid salt, and may include distillation and purification by supplying the formic acid salt to the formic acid separation unit 300. Specifically, the stream 5 supplied to the formic acid separation unit 300 may contain water, amine-based compounds, etc., along with formate, and the separated water and amine-based compounds among them are a carbon dioxide collection unit as a stream 6 Can be supplied to 400. In addition, the formic acid separated in the stream 5 may be separated from formic acid through distillation and purification processes, and the separated formic acid may be obtained as the stream 10.

In the process A-3, the formic acid separation unit 300 may include an evaporator, a distiller, a purifier, and the like.

As described above, since the present invention produces formic acid by obtaining carbon dioxide and hydrogen, which are raw materials for producing formic acid through syngas, economical efficiency can be improved compared to the conventional formic acid production process using purified carbon dioxide and hydrogen. In addition, according to the present invention, as the heterogeneous catalyst is used, the amine compound used in the reaction can be easily recovered, and the recovered amine compound is recycled back to the formic acid production process to capture carbon dioxide. It is possible to obtain a carbon dioxide reduction effect while increasing the efficiency of the manufacturing process.

Hereinafter, the present invention will be described in more detail by examples. However, the following examples are intended to illustrate the present invention, and that various changes and modifications are possible within the scope of the present invention and the scope of the technical idea is obvious to those skilled in the art, and the scope of the present invention is not limited thereto.

[ Example One] CTF (covalent triazine framework) On the carrier ruthenium( Ru ) Is supported catalyst preparation

1) Synthesis of CTF carrier mixed with bipyridine (bpy)-terephthalonitrile (TN)

After uniformly mixing 5 g of DCBPY (5.5'-dicyano-2,2'-bipyrindine) and 95 g of TN (terephthalonitrile), put the mixture in a 500 ml high-pressure reactor, dry, and then add 548 g of _{zinc chloride (ZnCl 2 ).} Sealed. Then, after heating at 400°C for 48 hours, the obtained product was crushed, put in 2000 ml of 1 M HCl aqueous solution, treated for 2 hours, and then the obtained product was washed with water and dried to form a CTF carrier (bpyTN-30-CTF. ) Was synthesized.

2) Preparation of ruthenium (Ru) supported catalyst

0.777 g of RuCl ₃ was dissolved in 300 ml of methanol, and 9.23 g of the synthesized bpyTN-30-CTF carrier was dispersed in a methanol solution in _{which RuCl 3 was dissolved.} Then, the mixture was boiled while refluxing for about 48 hours, washed with methanol at room temperature, and dried to prepare a Ru-bpyTN-30-CTF catalyst.

3) Check physical properties

In order to confirm the physical properties of the prepared Ru-bpyTN-30-CTF catalyst, EDX mapping, HAADF-STEM image, XPS and XAS spectra analysis were performed by a conventional method, and the results are shown in FIG. 2. FIG. 2A) shows the EDX mapping result, and FIG. 2B) shows the HAADF-STEM image result. It was confirmed that Ru was well dispersed in the carrier. In addition, Fig. 2C) shows that Ru is mainly present as Ru(III) as a result of XPS, and Fig. 2D) shows that Ru is well bound to the triazine structure as a result of XAFS spectra.

[ Example 2] POP (porous organic polymer) On the carrier ruthenium( Ru )this Supported Catalyst preparation

1) Synthesis of POP carrier combined with melamine and terephthalaldehyde

Melamine 1.878 g and terephtalaldehyde 3.0 g were dissolved in 102.3 g of DMSO solution, stirred and refluxed for 22 hours, boiled, and the precipitated precipitate was filtered, washed sequentially with water-acetone-THF solution, and dried. POP with triazine structure The carrier was synthesized.

2) Preparation of ruthenium (Ru) supported catalyst

The synthesized POP carrier was dispersed in 160 ml of methanol, and RuCl ₃ was dissolved in 40 ml of methanol, put into a solution in which the POP carrier was dispersed, and boiled under reflux for 24 hours while stirring, followed by drying, and an argon atmosphere at 160 degrees. A catalyst was prepared through a process of heat treatment under (see FIG. 3 for a specific manufacturing process). At this time, three types of catalysts (Ru-POP1, Ru-POP2, and Ru-POP3) as shown in Table 1 below were prepared by controlling the amount of Ru supported.

In addition, an Ir-POP3 catalyst was prepared through the same procedure as above, except that IrCl _{3 was used instead of RuCl 3.}

3) Check physical properties

In order to confirm the physical properties of the prepared Ru-POP1, Ru-POP2, Ru-POP3 and Ir-POP3 catalysts, the specific surface area (S _BET ) and average pores of the catalyst were analyzed with a surface area analyzer (a Belsorp II mini (BEL Japan, Inc.)). The volume (Pore Volume) and the average pore size (BJH Pore Size) were analyzed, and the amount of supported Ru (Metal Loading) was analyzed by ICP-OES (Inductively Coupled Plasma optical emission spectroscopy), and the results are shown in Table 1 below. Shown in.

division	S BET (m 2 g -1 )	Pore Volume (cm 3 g -1 )	BJH Pore Size (nm)	Metal Loading (wt%)
POP	810	0.92	4.5	-
Ru-POP1	846	0.98	4.6	0.32
Ru-POP2	583	0.83	5.7	0.63
Ru-POP3	574	0.76	5.2	1.08
Ir-POP3	580	0.77	5.1	1.10

Referring to Table 1, it was confirmed that the POP carrier had a triazine structure while having porosity with a specific surface area of 810 m ^{2 /g.} In addition, it can be seen that as the amount of supported Ru increases, the specific surface area and average pore volume decrease, and through this, it was confirmed that Ru was well supported.

[ Example 3] Graphite Nitrogen of the bond ( graphitic -N) containing On the carrier Preparation of catalysts supporting ruthenium (Ru), gold (Au), palladium (Pd), iron (Fe), and cobalt (Co)

1) Graphitic-N-containing carrier synthesis

70 mg of graphene nanoplatelets (GN) was added to 50 ml of distilled water, and sonicated for 30 minutes to obtain a solution. To the obtained solution, 1400 mg and 2800 mg of dicyanamide (DCDA) were added, and ultrasonic treatment was performed again for 30 minutes. After that, to remove all of the distilled water, it was heated at 95 degrees while stirring to obtain a powder. The obtained powder was ground, and for nitrogen doping, the powder was calcined at 900° C. for 2 hours under an argon atmosphere to synthesize a nitrogen-doped graphene nanoplatelet (NGN) carrier.

2) Ruthenium ( Ru ), gold (Au), palladium (Pd), iron (Fe) and cobalt (Co), respectively Supported Catalyst preparation

The same as in Example 1, except that 2wt% of _{RuCl 3,} 2wt% AuCl _3, 2wt% PdCl _2, 2wt% FeCl _{3 and} 2wt% CoCl ₃ were supported by using an NGN carrier instead of the bpyTN-30-CTF carrier. Through the process, Ru-NGN, Au-NGN, Pd-NGN, Fe-NGN, and Co-NGN catalysts were prepared, respectively.

[ Example 4] Pyrrole bond nitrogen ( pyrrollic Preparation of a catalyst in which ruthenium (Ru) is supported on a carrier containing -N) and pyridine-bonded nitrogen (piridinic-N)

1) Pyrrole bond nitrogen ( pyrrollic -N) and nitrogen of the pyridine bond ( piridinic -N) containing carrier synthesis

Adenine and magnesium hydrochloride (MgCl ₂ ·6H ₂ O) were added to mortar at a weight ratio of 1:10 and mixed to obtain a mixture. The obtained mixture was put in a ceramic boat and fired for 1 hour in a nitrogen atmosphere to obtain a fired product. The resulting fired product was treated with a 2 M HCl solution to remove residual magnesium components, washed with water, and dried to obtain a carrier containing pyrrole-bonded nitrogen and pyridine-bonded nitrogen. At this time, two types of carriers (C800A and C1000A) were synthesized, respectively, by adjusting the firing temperature to 800 degrees and 1000 degrees. Referring to FIG. 4, it was confirmed that nitrogen was contained in carbon grids such as pyrollic-N and piridinic-N in each of the prepared carriers. 4 is an analysis result of a carrier by X-ray photoelectron spectroscopy (XPS).

2) Preparation of ruthenium (Ru) supported catalyst

and bpyTN-30-CTF 800 degrees C800A a carrier, the firing temperature in place of the carrier, RuCl ₃ using a 1000 DEG C1000A carrier Ru-C800A and Ru-C1000A catalysts were each prepared through the same procedure as in Example 1, except that 3 wt% was supported.

[ Example 5] Pyrrole bond nitrogen ( pyrrollic -N) and nitrogen of a pyridine bond (piridinic-N) On the carrier Preparation of a catalyst in which gold (Au), palladium (Pd), iron (Fe) and cobalt (Co) are supported respectively

Adenine and metal salts AuCl ₃ , PdCl ₂ , FeCl ₃ and CoCl ₃ were each added to mortar at a weight ratio of 1:10 and mixed to obtain a mixture. Each of the obtained mixtures was placed in a ceramic boat and fired at 800 degrees for 1 hour under a nitrogen atmosphere to obtain fired products. Each obtained fired product was treated with 0.1M HCl solution to remove residual metal components, washed with water, dried, and Pd-C800A, Au-800A, Fe in which each metal was supported on a carrier containing nitrogen of pyrrole bonds and nitrogen of pyridine bonds. -800A and Co-800A catalysts were prepared respectively.

[Example 6] Preparation of a catalyst supporting ruthenium (Ru) on a titania carrier

1) synthesis of titania carrier

After mixing 200 ml of 28% aqueous ammonia and 50 ml of titanium isoproxoxide in an ice bath, stirring for 1 hour, filtered with water and ethanol, and dried under vacuum at 80° C. to obtain _{Ti(OH) 4.} The obtained Ti(OH) ₄ 1 g and melamine were mixed, ground with a mortar, and then calcined at 550 degrees for 8 hours to obtain a nitrogen-doped titanium dioxide carrier. At this time, the amount of melamine was adjusted to 1g, 2g, 3g, and 4g to synthesize four types of titanium dioxide carriers. Figure 5 is an XPS analysis of four types of titanium dioxide carriers, Figure 5 (in Figure 5 (a) is a survey spectrum, (b) is a narrow spectrum of the N1s peak of the carrier to which melamine 2g is applied, (c) is melamine 3g Referring to the narrow spectrum of the N1s peak of the carrier to which this was applied, (d) is the narrow spectrum of the N1s peak of the carrier to which 4g of melamine was applied), it was found that nitrogen in the form of Ti-N-0 in the lattice was present in each titanium dioxide carrier prepared. It could be confirmed by X-ray photoelectron spectroscopy.

2) Preparation of ruthenium (Ru) supported catalyst

Each synthesized titanium dioxide carrier and _{2 wt% of RuCl 3} were added to distilled water, stirred at 100° C. for 24 hours, distilled water was removed, and vacuum dried at 100° C. for 24 hours to prepare 4 types of catalysts, respectively.

[Experimental Example 1]

The activities of the catalysts prepared in Examples 1 to 5 were evaluated under the conditions of Table 2 below using a 150 ml stainless steel high-pressure stirred reactor. Specifically, after Et3N (Triethylamine) was introduced into a stirred reactor, the catalysts prepared in Examples 1 to 5 were put into a stirred reactor and purged with carbon dioxide to remove air. After making the pressure of carbon dioxide to be 40 atm, hydrogen was supplied to maintain the pressure at 80 atm, and the reaction temperature was raised to 120 degrees to proceed with the reaction at 120 atm. Subsequently, a product obtained through the reaction was obtained, and the amount (concentration) of formate in the product was analyzed by liquid chromatography (HP LC, high performance chromatography), and the results are shown in Table 2 below. At this time, the amount of the solvent used in the reaction was 40 ml. In addition, TOF h ^-1 means the molar ratio of formic acid converted for 1 hour to the total moles of active metal.

catalyst	Catalyst amount (mg)	Ru supported amount (wt%)	Reaction time (h)	Et3N concentration (M)	Formate (M)	TOF h -1
Ru-bpyTN-30-CTF	10	One	2	3	0.55	11117
Ru1-POP	60	0.32	2	One	0.09	948
Ru2-POP	60	0.63	2	One	0.42	2246
Ru3-POP	60	1.08	2	One	0.47	1466
Ru-NGN	70	2.0	2	One	0.72	1040
Ru-C800A	60	2.0	2	3	1.4	2358
Ru-C1000A	60	2.0	2	3	1.1	1853
Pd-800A	60	0.8	2	One	0.21	758
Au-800A	60	0.9	12	One	0.23	123
Fe-800A	60	1.1	12	One	0.09	39
Co-800A	60	0.8	12	One	0.10	60

Referring to Table 2, it was confirmed that the Ru-bpyTN-30-CTF catalyst in which Ru was supported on the CTF carrier had high activity due to the large amount of formate produced relative to the amount of the catalyst used.

[Example 7]

Ir-bpyTN-30-CTF catalyst was prepared through the same procedure as in Example 1, except that IrCl ₃ was used instead of RuCl _3.

[Example 8]

An Ir1-POP catalyst was prepared in the same manner as in Example 2, except that IrCl _{3 was used instead of RuCl 3.}

[Example 9]

An Ir-NGN catalyst was prepared through the same procedure as in Example 3, except that IrCl _{3 was used instead of RuCl 3.}

[Example 10]

Ir-C800A catalyst was prepared through the same procedure as in Example 4, except that IrCl ₃ was used instead of RuCl _3.

[Experimental Example 2]

The activity of the catalysts prepared in Examples 7 to 10 was evaluated under the reaction process of Experimental Example 1 and the conditions in Table 3 below, and the results are shown in Table 3 below.

catalyst	Catalyst amount (mg)	Ir supported amount (wt%)	Reaction time (h)	Et3N concentration (M)	Formate (M)	TOF h -1
Ir-bpyTN-30-CTF	10	One	2	3	0.45	9096
Ir1-POP	60	0.63	2	One	0.35	1872
Ir-NGN	70	2.0	2	One	0.6	866
Ir-C800A	60	2.0	2	3	1.0	1684

Referring to Tables 2 and 3, it was confirmed that the catalyst supported with Ru had higher activity than the catalyst supported with Ir.

[Example 11]

A Ru-bpyTN-30-CTF catalyst was prepared in the same manner as in Example 1, except that a combination of Ru and acetate was used instead of _{RuCl 3.}

[Example 12]

A Ru-bpyTN-30-CTF catalyst was prepared in the same manner as in Example 1, except that a combination of Ru and acetylacetonate was used instead of _{RuCl 3.}

[Experimental Example 3]

The activity of the catalysts prepared in Examples 1, 11 and 12 was evaluated under the reaction process of Experimental Example 1 and the conditions in Table 4 below, and the results are shown in Table 4 below.

catalyst	Catalyst amount (mg)	Ru supported amount (wt%)	Metal salt Ligand	Et3N concentration (M)	Formate (M)	TOF h -1
Ru-bpyTN-30-CTF	10	One	Chlorine	2	0.48	18452
Ru-bpyTN-30-CTF	10	One	acetate	2	0.35	13455
Ru-bpyTN-30-CTF	10	One	Acetyl Acetonate	2	0.41	15761

Referring to Table 4, it was confirmed that even if the metal salt ligand was changed, the activity of the catalyst was maintained at the same level.

[Experimental Example 4]

The activity of the catalyst prepared in Example 6 was evaluated according to the reaction process of Experimental Example 1 and the conditions in Table 5 below, and the results are shown in Table 5 below. At this time, evaluation was carried out by adding a catalyst prepared using a titanium dioxide carrier (no nitrogen doped) synthesized with a melamine amount of 0 g.

Melamine Usage (g)	Firing temperature (℃)	Ru supported amount (wt%)	Catalyst amount (mg)	Reaction time (h)	Et3N concentration (M)	Formate (M)	TOF h -1
0	550	2	60	2	One	0.03	201
One		2	60	2	One	0.13	906
2		2	60	2	One	0.27	1867
3		2	60	2	One	0.22	1549
4		2	60	2	One	0.18	1245

Referring to Table 5, it was confirmed that the catalyst prepared using the titanium dioxide carrier doped with nitrogen has higher activity compared to the titanium dioxide carrier not doped with nitrogen.

[Experimental Example 5]

In order to check the reactivity according to the amine-based compound in the formate production process, the reaction was carried out in the reaction process of Experimental Example 1 and the conditions of Table 6 below using the catalyst prepared in Example 1. Indicated.

catalyst	Catalyst amount (mg)	Amine compounds	Amine concentration (M)	Formate (M)	TOF h -1
Ru-bpyTN-30-CTF	10	Triethylamine	3.0	0.55	11117
Ru-bpyTN-30-CTF	10	Tributylamine	3.0	0.04	808
Ru-bpyTN-30-CTF	10	Trihexylamine	3.0	0.01	202
Ru-bpyTN-30-CTF	10	1,4-dimethyl piperazine	3.0	0.6	12127
Ru-bpyTN-30-CTF	10	Butylmorpholine	3.0	0.43	8692
Ru-bpyTN-30-CTF	10	N-methyl pyrrolidine	3.0	0.61	12330

Referring to Table 6, it was confirmed that the catalyst activity was high when triethylamine, N-methyl pyrrolidine, and 1,4-dimethyl piperazine were used among the tertiary amines.

[ Example 13]

_{RuO (OH) x} -N-TiO ₂ catalyst was prepared in the same manner as in Example 6, except that ruthenium oxide was used instead of RuCl _3. At this time, a process of dispersing 2 g of a titanium dioxide carrier supported with Ru in 60 ml of an aqueous solution, slowly adding 1 M NaOH aqueous solution, stirring for 24 hours while adjusting the pH of the solution to 13.2, filtering, washing with water, and drying. I went through additionally.

[ Example 14]

A _{RuO(OH) x} -N-TiO ₂ catalyst was prepared in the same manner as in Example 6, except that iridium oxide (hydrous ruthenium) was used instead of _{RuCl 3.} At this time, a process of dispersing 2 g of an Ir-supported titanium dioxide carrier in 60 ml of an aqueous solution, slowly adding 1 M NaOH aqueous solution, stirring for 24 hours while adjusting the pH of the solution to 13.2, filtering, washing and drying. I went through additionally.

[Experimental Example 6]

The activity of the catalysts prepared in Examples 13 and 14 was evaluated under the reaction process of Experimental Example 1 and the conditions in Table 7 below, and the results are shown in Table 7 below.

catalyst	Catalyst amount (mg)	Ru/Ir loading amount (wt%)	Et3N concentration (M)	Formate (M)	TOF h -1
RuO(OH) x -N-TiO 2	60	2	One	0.58	977
IrO(OH) x -N-TiO 2	60	2	One	0.45	1441

Referring to Tables 5 and 7 above, it was confirmed that the activity of the catalyst was higher when using ruthenium oxide or iridium oxide than _{RuCl 3.}

[Example 15]

In order to check the catalytic activity in the fixed bed reactor as shown in FIG. 6, the reaction was carried out under the following conditions. At this time, the unreacted gas was not recycled. Specifically, 1.5 g of the Ru-bpyTN-30-CTF catalyst prepared in Example 1 was fixed in the middle of a fixed bed reactor (diameter: 1/2 inch, length: 60 cm) to form a catalyst layer. Beads were filled. A preheater was placed at the tip of the reactor. The temperature of the preheater was maintained to be the same as the reaction temperature. Water and Et3N were quantified by a separate liquid transfer pump and introduced into the reactor, and hydrogen was introduced into the reactor by raising the pressure to the reaction pressure with a compressor. Carbon dioxide maintained in liquid form in a vessel maintained at 60 atmospheres was introduced into the reactor by a liquid transfer pump, and carbon dioxide was vaporized before the reaction. The reaction temperature was maintained by a temperature controller, and a pressure controller was placed at the rear end of the vessel for collecting the reaction product to maintain the reaction pressure.

The reaction proceeded under these conditions, but _{the reaction was proceeded by adjusting the reaction pressure, reaction temperature, the molar ratio of H 2} /CO ₂ of the feed solution, the molar ratio of Et3N/CO ₂ and the concentration of Et3N, and the productivity of formate was evaluated after the reaction was completed. It is shown in FIG. 7.

(A) of FIG. 7 shows the productivity of formate according to the reaction temperature under the reaction conditions in which the molar _{ratio of H 2} /CO ₂ in the feed solution is 1.0, the molar ratio of Et3N/CO _{2 is 1.0, and the concentration of Et3N is 3M at a reaction pressure of 100 atm.} As shown, it was confirmed that the productivity of formate increased as the reaction temperature increased. Specifically, at a reaction temperature of 140 degrees and a reaction pressure of 100 atm, the productivity of formate was 355.1 gHCOOH/gcat/d, and the conversion rate of carbon dioxide was confirmed to be 71.3% under this reaction condition.

(B) of FIG. 7 shows the productivity of formate according to the reaction pressure under the reaction conditions in which the molar _{ratio of H 2} /CO ₂ in the feed solution is 1.0, the molar ratio of Et3N/CO _{2 is 1.0, and the concentration of Et3N is 3M at a reaction temperature of 120 degrees.} As shown, it was confirmed that the productivity of formate increased as the reaction pressure increased.

(C) of FIG. 7 shows formic acid according to the change in concentration of Et3N under a reaction condition in which the molar _{ratio of H 2} /CO ₂ in the feed solution is 1.0 and the molar ratio of Et3N/CO ₂ is 1.0 at a reaction pressure of 120 atm and a reaction temperature of 120 degrees. As a result of showing the productivity of the salt, it was confirmed that the productivity of formate was the highest at 340 gHCOOH/gcat/d under the reaction condition of the Et3N molar ratio of 3.0.

_{(D) of FIG. 7 shows that the molar ratio of Et3M/CO 2} is changed _{under the reaction conditions in which the H 2} /CO ₂ molar ratio of the feed solution is 1.0 and the concentration of Et3N is 3M at a reaction temperature of 120 degrees and a reaction pressure of 120 atm. illustrates the production of formic acid salts and CO ₂ conversion rate of the _second contact time, the higher the molar ratio of Et3N / CO ₂ increase with decreasing the contact time of CO _2, it was confirmed that the formate salt increase productivity. Further more the molar ratio of Et3N / CO ₂ increases with increasing the contact time of CO ₂ was confirmed that the CO ₂ conversion decreases. Specifically, when the contact time of _{CO 2 was 1 minute and the molar ratio of Et3N/CO 2} was 1.0, the CO ₂ conversion rate was 43.6%, and at this time, the productivity of formate was 650 gHCOOH/gcat/d.

Meanwhile, the reaction product obtained after completion of the reaction was analyzed by liquid chromatography (HPLC, high performance chromatography), and the gas composition obtained after completion of the reaction was analyzed by gas chromatography. From the analysis results, it was confirmed that carbon monoxide was hardly detected, so that the selectivity of formate reached almost 100%.

[Example 16]

As shown in Figure 8 In order to check the catalytic activity in the fluidized bed reactor, the reaction was carried out under the following conditions. Specifically, 3 g of the Ru-bpyTN-30-CTF catalyst prepared in Example 1 was dispersed in a fluidized bed reactor (diameter: 3/8 inch, length: 1 m). Here, the tube for separating the catalyst at the top has a diameter of 1 inch and a length of 30 cm. In addition, the tube was made to be able to control the temperature by using a tubular band heater. The reactor was filled with Et3N with a gas sparger to prevent liquid from entering the lower end of the reactor. The reaction was carried out while supplying 761.6 ml/min of carbon dioxide, 761.6 ml/min of hydrogen, 3.0 ml/min of water, and 2.34 ml/min of Et3N at a reaction temperature of 120 degrees and a reaction pressure of 120 atm.

After the reaction was completed, a reaction product was obtained from the upper part of the reactor, which was analyzed by liquid chromatography (HPLC, high performance chromatography). In addition, the gas composition obtained after completion of the reaction was analyzed by gas chromatography. In the analysis results, the CO ₂ conversion rate was 37%, and the productivity of formate was 280 gHCOOH/gcat/d. In addition, since carbon monoxide was hardly detected, it was confirmed that the selectivity of formate reached almost 100%.

[Example 17]

Formic acid was prepared using methane (synthetic gas) through a process chart as shown in FIG. 9.

Specifically, methane (3,196.8 kg/h) and steam (12,603 kg/h) were supplied to the methane reforming reactor (R2) maintained at 850 degrees and 20 atmospheres to react. After the reaction, heat was recovered through a heat exchanger, and then methane (184.0 kg/h), carbon monoxide (3398.3 kg/h), carbon dioxide (2979.3 kg/h), and hydrogen (1267.3 kg) were passed through conditions of 450 degrees and 20 atmospheres. /h) and steam (7980 kg/h). The amount of heat recovered here was 4.9 M*kcal/h. Next, the reformer product was subjected to a water gas reaction through a high temperature water gas reactor (R3) at 450°C and a low temperature water gas reactor (R4) at 210°C, through this reaction, methane (184.0 kg/h) and carbon monoxide (71.5 kg/h) h), carbon dioxide (8208 kg/h), hydrogen (1504.6 kg/h) and steam (5840 kg/h). This water gas composition (stream (3)) was pressurized from 20 atm to 120 atm by a compressor to remove water, and then supplied to a formate generating reactor (R1).

Meanwhile, the product (stream (7)) in _{which CO 2} supplied from the carbon dioxide absorption tower (A) _{is absorbed is composed of CO 2} (25080 kg/h), Et3N (95725 kg/h), and water (183412 kg/h). It was supplied to the formate generating reactor (R1). In addition, unreacted methane (7868 kg/h), carbon monoxide (2876 kg/h), carbon dioxide (47654 kg/h), hydrogen (2421 kg/h) and water in the gas stream (2745 kg/h) are formate. It was cycled through the production reactor (R1). As a result, stream (3), stream (7) and stream (4) were supplied to the formate generating reactor (R1).

The formate generating reactor (R1) was filled with 400 kg of the catalyst Ru-bpyTN-30-CTF prepared in Example 1, and the CO ₂ conversion rate was about 40%. Methane (8557 kg/h), carbon monoxide (3132 kg/h), carbon dioxide (50401 kg/h), hydrogen (2555 kg/h), water (183614 kg/h) to the bottom of the formate generating reactor (R1) , Et3N (95725 kg/h) and formic acid (35331 kg/h) were discharged. Here, the amount of formic acid was calculated through the amount of the additive compound in which formate and Et3N were combined. Specifically, additional compounds ^{Et3NH +: HCOO - (1:} 0.81) , and the one in parentheses: 0.81 is added at HCOO ^compound indicates the molar ratio of Et3NH ⁺ for.

The reactant (Stream (5)) was gas-liquid separation in vessel GL and was maintained to have a temperature of about 80 degrees. Of the separated gas component is refluxed in formic acid generation reactor ^{(R1) Et3NH +: HCOO -} : it was supplied to the addition compound 131056 kg / h water, and 186333 kg / h is evaporated tower (Ev) of (1 0.81). The evaporation tower (Ev) was 1.2 m in height and was filled with a lash ring, and the pressure was maintained at 150 mmHg. In the upper part of the evaporation column (Ev) were a Stream with water 186333 kg / h and Et3N composition of 61934 kg / h discharged, in the lower portion of the evaporation column ^{(Ev) Et3NH +: HCOO -} (1: 2.3) additional compound (formic acid 35 331 kg/h and Et3N 33791 kg/h were obtained). Et3N and water discharged from the top of the evaporation tower (Ev) are phase-separated, and these are mixed in the vessel (V4) together with 33791 kg/h of Et3N discharged from the top of the distillation column (D1) and phase-separated. It was supplied to the feed tank (T2). Here, the distillation column (D1) was 2.5 m in height and was filled with structured packing. Thereafter, Et3N and water (Stream (6)) were supplied to the carbon dioxide absorption tower (A), and the carbon dioxide contained in the combustion exhaust gas was absorbed by the carbon dioxide absorption tower (A) as _{a product in which CO 2} was absorbed (stream (7)). , Was recycled to the formate generating reactor (R1).

On the other hand, the Et3NH ⁺ discharged from the lower portion of the evaporation column ^{(Ev): HCOO - (1} : 2.3) additional compound nBIMH ⁺ which was supplied to the storage container (V2), discharged from the bottom of the purifying column (D2): HCOO ^- ( 1:0.18) adduct 124067 kg / h and mixed to form a mixture, and the formed mixture (stream (10)) was fed to the distillation column (D1). Here, 1:0.81 in parentheses ^{represents the molar ratio of nBIMH + to HCOO-} in the adduct compound, and nBIM represents n-butylimidazole.

After became Et3N 33791 kg / h discharged from the upper portion of the distillation column (D1), the lower the ^{nBIMH +: HCOO - (1:} 1) addition compound 159398 kg / h has been discharged, the additional compounds were stored in a storage container (V3) . The nBIMH+:HCOO-(1:1) adduct (stream (11)) stored in the storage container (V3) was supplied to the purification tower (D2) and subjected to purification. After purification in the upper portion of the purifying column (D2) were be pure formic 35331 kg / h is obtained is discharged, in the lower portion of the purifying column ^{(D2) nBIMH +: HCOO -} (1: 0.18) additional compound 124067 kg / h is discharged And it was recycled to the storage vessel (V2).

Claims (16)

1. Supplying the syngas to a water gas conversion unit to convert carbon monoxide contained in the syngas into hydrogen and carbon dioxide;

   Supplying a mixed gas containing hydrogen and carbon dioxide converted by the water gas conversion unit to a formate generating unit equipped with a catalyst to generate formate; And

   And supplying the formic acid salt to a formic acid separation unit to separate formic acid,

   The synthesis gas is a process for producing formic acid that is derived from at least one selected from the group consisting of hydrocarbons having 1 to 5 carbon atoms, coal, biomass, biogas, and steelworks by-product gas.
2. The method of claim 1,

   Further comprising a step of supplying the combustion exhaust gas and the amine compound to the carbon dioxide capture unit to produce a carbonic acid-amine adduct,

   The carbonic acid-amine addition compound is supplied to the formic acid generating unit for producing formic acid.
3. The method of claim 2,

   The carbonic acid-amine adduct is supplied to the formate generating unit when the molar ratio (b/a) of carbon dioxide (a) and hydrogen (b) contained in the mixed gas is lower than 2.0.
4. The method of claim 2,

   The amine-based compound is a compound represented by the following formula (1), the process for producing formic acid:

   [Formula 1]

   NR ₁ R ₂ R ₃

   In Formula 1,

   R ₁ to R ₃ are the same as or different from each other, and each independently selected from the group consisting of hydrogen, an alkyl group having 1 to 6 carbon atoms, and a cycloalkyl group having 3 to 10 carbon atoms or bonded to each other to form an aliphatic ring or an aromatic ring,

   The _{alkyl group and the cycloalkyl group of R 1} to R ₃ are each independently substituted or unsubstituted with one or more substituents selected from the group consisting of an alkyl group having 1 to 10 carbon atoms and an aryl group having 6 to 10 carbon atoms.
5. The method of claim 4,

   The amine compound is trimethylamine, triethylamine, tripentylamine, tripropylamine, tributylamine, trihexylamine, N,N- The manufacturing process of formic acid that is at least one selected from the group consisting of dimethylbutylamine (N,N-dimethylbutylamine), dimethylcyclohexylamine, dimethylphenethylamine, and isoamylamine.
6. The method of claim 2,

   The amine-based compound is in the group consisting of dialkyl piperazine (N,N-dialkyl piperazine), morpholine, alkyl morpholine, alkyl piperidine and alkylpyrrolidine. The manufacturing process of formic acid that is one or more selected.
7. The method of claim 1,

   The process for producing formic acid wherein separate carbon dioxide is additionally supplied to the formate generating unit together with the mixed gas.
8. The method of claim 1,

   The catalyst provided in the formate generation unit is a process for producing formic acid in which the active metal is supported on a porous carrier containing at least one of nitrogen and phosphorus.
9. The method of claim 8,

   The active metal is iridium (Ir), ruthenium (Ru), palladium (Pd), gold (Au), iron (Fe) and cobalt (Co) at least one selected from the group consisting of formic acid production process .
10. The method of claim 8,

    The porous carrier includes porous organic framworks, covalent organic frameworks, covalent triazine frameworks, porous aromatic frameworks, and porous organic polymers. Organic polymer) is a manufacturing process of formic acid containing at least one selected from the group consisting of.
11. The method of claim 10,

    The porous carrier is a process for producing formic acid that includes a triazine structure or a heptazine structure.
12. The method of claim 8,

    The porous carrier is 1 selected from the group consisting of pyridine bonded nitrogen (pyridinic-N), pyrrole bonded nitrogen (pyrrolic-N), pyrazole bonded nitrogen (pyrazole-N) and graphite bonded nitrogen (graphitic-N). The manufacturing process of formic acid containing more than one species.
13. The method of claim 8,

    The porous carrier is a process for producing formic acid containing at least one selected from the group consisting of titania, alumina, gallia, zirconia, and silica in which nitrogen or phosphorus is contained in the skeletal structure.
14. A water gas conversion unit for converting carbon monoxide contained in the synthesis gas into hydrogen and carbon dioxide by a water gas reaction of the synthesis gas;

    A formate generating unit for generating formate by reacting the mixed gas containing hydrogen and carbon dioxide with an amine-based compound in the presence of a catalyst; And

    Including a formic acid separation unit for separating formic acid from the formic acid salt,

    The synthesis gas is derived from at least one selected from the group consisting of hydrocarbons having 1 to 5 carbon atoms, coal, biomass, biogas, and steel mill by-product gas.
15. The method of claim 14,

    The apparatus for producing formic acid further comprises a carbon dioxide capture unit for generating a carbonic acid-amine adduct by reacting the combustion exhaust gas with the amine compound.
16. The method of claim 14,

    The formic acid production apparatus comprises at least one selected from the group consisting of a stirred reactor, a fixed bed reactor, and a fluidized bed reactor.

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