KR102294427B1 - Manufacturing apparatus and manufacturing process of formic acid using synthesis gas - Google Patents

Abstract

The present invention relates to a process and apparatus for producing formic acid from synthesis gas, specifically, a mixed gas (mixture) of hydrogen and carbon dioxide produced by a water gas conversion reaction of synthesis gas, and an amine compound as a reaction medium. The present invention relates to a process and an apparatus for producing formic acid by introducing an amine addition compound that captures carbon dioxide from an exhaust gas discharged by combustion into a reactor.

Description

Manufacturing process and manufacturing apparatus of formic acid using syngas

The present invention relates to a process and an 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 adjuvant, disinfectant or textile for acidification in the manufacture of animal feed, as an adjuvant in the leather industry, as a reactant for deicing of aircraft or runways, and the like.

Conventionally, one of the processes for commercially producing formic acid was to carbonyl the synthesized methanol to prepare methyl formate and to hydrate it. In this process, in order to produce 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 made on a process capable of producing formic acid in only one step using the hydrogenation reaction of carbon dioxide. As an example, there is a process for producing formic acid by reacting carbon dioxide and hydrogen in a high-pressure stirred reactor containing a homogeneous catalyst and an amine. In the process for producing formic acid through the hydrogenation of carbon dioxide, a catalyst having a high activity for the hydrogenation reaction may also exhibit a large activity for the decomposition reaction of formic acid. Therefore, it is very important to recover the catalyst in order to obtain a high yield of formic acid by suppressing the decomposition of formic acid.

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

In order to solve this problem, US 20120157711A1 discloses that in order 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, an amine having 6 or more carbons per molecule is used as a catalyst, and , It has been disclosed that separately adding an alcohol solvent.

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 a hydrogenation reaction using a stirred reactor under heterogeneous catalyst conditions such as an Ag catalyst, but a problem occurred that the reaction activity was low at a pressure condition of 180 atmospheres or more (Angew.Chem.123 (2011) 12759) . In addition, when carbon dioxide is directly hydrogenated, excessive costs are consumed for carbon dioxide capture and hydrogen production, 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) There were problems in that it was difficult to secure economic feasibility due to the excessive amount of carbon dioxide, and the reduction effect of carbon dioxide was lowered.

US 2012157711 A1

Angew.Chem.123 (2011) 12759 J. Clean Prod. 85 (2014) 151-163

The present invention prepares a mixture of hydrogen and carbon dioxide by a water gas reaction of syngas, introduces it directly into a formate generation reactor without a separate separation process, and uses an amine as a reaction medium to capture additional carbon dioxide, which is then directly carbon dioxide By producing formic acid by using the hydrogenation reaction of the formic acid, it is intended to solve the problem that excessive cost is consumed for the production of formic acid and the reduction effect of carbon dioxide is poor. In addition, by using a heterogeneous catalyst, the problem of the homogeneous catalyst is to be solved.

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 the synthesis gas to a water gas conversion unit together with a required amount of water; supplying the mixed gas containing carbon dioxide and hydrogen converted in the water gas conversion unit to a formate generating unit equipped with a formic acid manufacturing catalyst to generate formate; and supplying the formic acid salt to a formic acid separation unit to separate formic acid, 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 steelworks by-product gas. It provides a process for producing 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 generator for generating a formate by reacting the mixed gas containing hydrogen and carbon dioxide with an amine 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 steel mill by-product gas. An apparatus for producing formic acid is provided.

As the present invention uses synthesis gas as a reaction raw material, it is not necessary to use purified carbon dioxide and hydrogen as reaction raw materials for the hydrogenation of carbon dioxide. have. In addition, according to the present invention, since the formate generator filled with the heterogeneous catalyst is used, a catalyst component is not contained in the product, a separate catalyst recovery system is not required, and it is possible to prevent the catalyst particles from being crushed.

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

1 is a flowchart for explaining a manufacturing process and manufacturing apparatus of 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 flowchart illustrating a process for preparing a 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 view showing a fixed bed reactor used in the process for producing 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 process for producing formic acid according to the present invention.
9 is a flowchart illustrating a process for producing formic acid according to Example 17 of the present invention.

The terms or words used in the description and claims of the present invention should not be construed as being limited to their ordinary or dictionary meanings, and the inventor should properly understand the concept of the term in order to best describe his invention. Based on the principle that can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

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

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 'process A-1'); a process for producing formate (hereinafter referred to as 'process A-2'); and a process of separating formic acid (hereinafter referred to as 'process A-3'). The process for producing formic acid according to the present invention may further include a process for producing a carbonate-amine addition compound (hereinafter referred to as 'Step A-4'), if necessary. In addition, the manufacturing process of formic acid according to the present invention may further include a process of gas-liquid separation of a product containing formic acid salt (hereinafter referred to as 'process A-5'), 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 if necessary. Also, 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 for generating carbon dioxide and hydrogen from carbon monoxide and water contained in synthesis gas, which is a reaction raw material. The synthesis gas is supplied to the water gas conversion unit 100 to convert carbon monoxide contained in the synthesis gas into hydrogen and carbon dioxide. It may 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 Scheme 1 below.

[Scheme 1]

CO + H ₂ O → CO ₂ + H ₂

The water gas reaction may be thermodynamically progressed to a complete reaction as the temperature is lower, and the conversion rate of carbon monoxide may be reduced as the temperature is higher. This water gas reaction may be performed in one step, but may be performed in two steps to increase the reaction efficiency. Specifically, the water gas reaction may be performed by passing a high temperature water gas reaction in which the reaction is performed at a high temperature of 300 degrees or more 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 at 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 catalyst such as Fe, Cr, Zn may be used for the high-temperature water gas reaction.

The low-temperature water gas reaction may be performed at 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, catalysts such as Cu, ZnO, Al 2} O ₃ and the like may be used for the low-temperature water gas reaction. In this case, 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. 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 of a steel mill. The reforming reaction and gasification reaction may be carried out in a commonly 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 generator 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 Since the capture and purification process of the formic acid is omitted, the efficiency (economical efficiency) of the formic acid production process can be increased compared to the prior art.

The A-4 process is a process for producing a carbonate-amine adduct compound, and may include a process of supplying combustion exhaust and an amine compound to the carbon dioxide collecting unit 400 to generate a carbonate-amine adduct compound. 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 not added to the formate generation reaction. It is performed when insufficient, and may include absorption of carbon dioxide by an amine-based compound as shown in Scheme 2 below. In this case, 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 amine compound as a reaction medium absorbs carbon dioxide contained in the combustion exhaust gas to NR ₁ R ₂ Carbonic acid-amine adducts such as R ₃ H ⁺ :HCO ₃ ^{- may be formed.} The carbonate-amine addition compound 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- ) may include ammonium salts. Also, the carbonate-amine addition compound may be in the form of an aqueous solution.

Here, when trialkylamine is used as the amine-based 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 as described above, the reaction efficiency in the carbon dioxide hydrogenation process may be lowered.

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

The amine-based compound reacting with the combustion exhaust may be a compound represented by Formula 1 below.

[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 are 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 are bonded to each other (eg, R ₁ and R ₂ of bonding, R ₂ and R ₃ , or R ₂ and R ₃ bonding) 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, specifically, a methyl group, an ethyl group, a propyl group, a butyl group, or the like. The cycloalkyl group may be specifically a cyclopropyl group, a cyclobutyl group, a cyclohexyl group, and the like. The aromatic ring may be an aromatic ring with or without 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 may be at least one selected from the group consisting of have.

In addition, the amine-based compound reacting with the combustion exhaust is dialkyl piperazine (N,N-dialkyl piperazine) such as dimethyl piperazine (N,N-dimethyl piperazine), diethyl piperazine (N,N-diethyl piperazine); morpholine; N-alkyl morpholine, such as methyl morpholine, N-ethyl morpholine, N-propyl morpholine, N-butyl morpholine, etc. ; alkylpiperidines such as methylpiperidine, ethylpiperidine, propylpiperidine, butylpipeirdine, and the like; And at least one selected from the group consisting of alkylpyrrolidine such as methylpyrrolidine, ethylpyrrolidine, propylpyrrolidine, butylpyrrolidine, and the like 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 process A-4, the carbon dioxide absorption reaction may be performed at a reaction temperature of 10 to 100 degrees (specifically, 20 to 80 degrees) and a reaction pressure of 1 to 50 atmospheres (specifically, 1 to 20 atmospheres).

The product including the carbonate-amine adduct generated through the process A-4 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 include carbonic acid-amine adducts, amine-based compounds, and carbon dioxide. Stream (7) may also contain a mixture of free amines or free carbonic acids with carbonate-amine adducts.

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

The A-2 process is a process for generating formate, which is a precursor of formic acid. The mixed gas containing carbon dioxide and hydrogen generated by the water gas conversion unit 100 is transferred to the formate generating unit 200 equipped with a catalyst. It can be made in the process of producing formate by supplying it. Specifically, in process A-2, a formate (amine-formic acid addition compound) is generated through a reaction of carbon dioxide, an amine-based 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 produced in the formate generating unit 200 (recovered through gas-liquid separation of formate), and supplied to the formate generating unit 200 as an auxiliary solvent. It may mean that the In addition, an auxiliary amine (eg, n-methylpyrrolidone and n-butylimidazole) derived from the formic acid separation unit 300 instead of water may be supplied as an auxiliary solvent, or a mixture of auxiliary amine and water may be supplied as an auxiliary solvent. have. The auxiliary amine is an aproctic tertiary amine, N-methylpyrrolidone (N-methylpyrrolidone), N-formyl morpholine (N-formyl morpholine), N-methylacetamide (N-methylacetamide) , N,N-dimethylacetamide, NN-diethylacetamide, N-ethylacetamide, N-butylimidazole , may be at least one selected from the group consisting of N-methylimidazole (N-methylimidazole) and N-ethylimidazole (N-ethylimidazole).

In Scheme 3, carbon dioxide (CO ₂ ) may be in a dissolved state in a solution. In addition, carbon dioxide (CO ₂₎ is a separate carbon dioxide (CO together with the carbon dioxide (CO ₂₎ or, formates mixed gas supplied to the generating unit 200 (stream 2)) converted from the water gas shift unit (100) ₂ ) may be additionally supplied. The separate carbon dioxide (CO ₂ ) may be supplied from the carbon dioxide collecting unit 400 or may be supplied through a carbon dioxide supply line (not shown) separately provided for the formate generating unit 200 .

In Scheme 3, the carbonate-amine addition compound (d NR ₁ R ₂ R ₃ H ⁺ :xHCO ₃ ⁻ ) refers to the one supplied from the above-described carbon dioxide collecting unit 400, and instead of the carbonate-amine addition compound, the amine-based compound A compound may participate directly 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. These amine-based compounds may be separated and discharged from the formic acid separation unit 300 as a stream 6 after the formate production reaction and supplied (circulated) to the carbon dioxide collecting unit 400 .

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

In general, a reaction for producing formic acid by hydrogenation of carbon dioxide is a nonspontaneous reaction, and ΔG (Gibbs-free energy change) may have a positive value. However, when an amine compound (NR ₁ R ₂ R ₃ of Formula 1) is used as in the present invention, ΔG (Gibbs-free energy change) of the hydrogenation reaction of carbon dioxide may have a negative value, so that the conventional carbon dioxide can overcome the thermodynamic limitations of the hydrogenation reaction of

Meanwhile, the molar ratio of hydrogen to carbon dioxide contained in the feed (stream (2)+(7)+(4) in FIG. 1) introduced to the formate generator 200 as 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, and 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 the yield of formic acid compared to carbon dioxide can be reduced. As the temperature increases, 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 can be minimized to provide optimal reaction conditions.

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

[Equation 1]

The hydrogenation reaction of carbon dioxide in step A-2 may be performed at a reaction temperature of 30 to 200 degrees (specifically, 40 to 150 degrees) and a reaction pressure of 20 to 200 atmospheres (specifically, 30 to 150 atmospheres). If the reaction temperature is less than 30 degrees, the catalyst activity may be lowered, and if it exceeds 200 degrees, the catalyst may be reduced and deactivated. In addition, when the reaction pressure is less than 20 atm, the catalyst activity may be lowered, and when it exceeds 200 atm, a lot of energy is consumed in the reaction, thereby reducing process efficiency.

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

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). The active metal may be derived from a compound containing the 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 active metal salt may be chloride, acetate, acetylacetonate, nitrate, hydroxide, sulfate or sulfide. .

In addition, the compound containing the active metal may be an oxide, a hydrated oxide thereof, a mixed oxide thereof, a reduced metal, or a mixed metal thereof.

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

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

In addition, the porous carrier containing at least one of nitrogen and phosphorus (specifically, the porous carrier in which nitrogen or phosphorus is contained in the framework 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 generating 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 catalyst stability.

The product containing the formate produced 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 include formate (amine-formic acid adduct), carbon dioxide, hydrogen and water. The stream (3) may also contain a mixture of free amines or free formic acid 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 for gas-liquid separation of a product containing formate, and may include supplying a product containing formate to the gas-liquid separation unit 500 to separate carbon dioxide and hydrogen. The 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 gas component separated from the formate-containing product may include carbon dioxide (unreacted carbon dioxide) and hydrogen, which may be supplied back to the formate generator 200 as a stream 4 . In addition, the liquid or liquid + solid component separated from the product containing formate may include formate (formic acid-amine adduct), which may be supplied to the formic acid separation unit 300 as stream 5 .

In the A-5 process, the gas-liquid separation may be performed at a temperature of 25 to 150 degrees (specifically, 40 to 100 degrees). Also, 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 for separating formic acid from formic acid salt. The formic acid salt is supplied to the formic acid separation unit 300 for distillation and purification. Specifically, the stream 5 supplied to the formic acid separation unit 300 may contain water, an amine compound, etc., along with formate, and the separated water and amine compound are the separated water and the amine compound as a stream 6 as a carbon dioxide collecting unit. 400 may be supplied. In addition, the formic acid separated from 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 A-3 process, the formic acid separation unit 300 may include an evaporator, a distiller, a purifier, and the like.

As described above, in the present invention, since formic acid is produced by obtaining carbon dioxide and hydrogen, which are raw materials for producing formic acid through synthesis gas, it is possible to increase economic efficiency compared to the conventional manufacturing process of formic acid using purified carbon dioxide and hydrogen. In addition, the present invention can easily recover the amine-based compound used in the reaction by using a heterogeneous catalyst, and as the recovered amine-based compound is recycled back to the formic acid production process and utilized to capture carbon dioxide, formic acid Carbon dioxide reduction effect can be obtained while increasing the efficiency of the manufacturing process.

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

[Example 1] Preparation of catalyst in which ruthenium (Ru) is supported on a CTF (covalent triazine framework)-based carrier

1) Bipyridine (bpy)-terephthalonitrile (TN) mixed CTF carrier synthesis

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 it, and then add 548 g of _{zinc chloride (ZnCl 2 )} sealed. After heating at 400 degrees for 48 hours, the obtained product was crushed, put in 2000 ml of an aqueous solution of 1 M HCl, treated for 2 hours, and the obtained product was washed and dried with water to obtain a CTF carrier (bpyTN-30-CTF) ) was synthesized.

2) Preparation of ruthenium (Ru) supported catalyst

RuCl ₃ 0.777 g 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, after boiling while re-refluxing for about 48 hours, it was 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 in a conventional manner, and the results are shown in FIG. 2 . 2A) shows the EDX mapping result, and FIG. 2B) shows the HAADF-STEM image result, and it was confirmed that Ru was well dispersed in the carrier. In addition, in Fig. 2C), it was confirmed that Ru was mainly present as Ru(III) as a result of XPS, and in Fig. 2D), it was confirmed that Ru was well bound to the triazine structure as a result of XAFS spectra.

[Example 2] Preparation of catalyst in which ruthenium (Ru) is supported on a porous organic polymer (POP) carrier

1) Synthesis of POP carrier combining melamine and terephthalaldehyde

After dissolving 1.878 g of melamine and 3.0 g of terephtalaldehyde in 102.3 g of DMSO solution, boiling while stirring and refluxing for 22 hours, the precipitated precipitate is filtered, washed with water-acetone-THF solution sequentially, and then dried POP with a triazine structure The carrier was synthesized.

2) Preparation of ruthenium (Ru) supported catalyst

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

In addition, an Ir-POP3 catalyst was prepared through the same process 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 ) of the catalyst, the average pore 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 specific surface area of the POP carrier was 810 m ² /g, which was porous and had a triazine structure. In addition, as the amount of supported Ru increased, the specific surface area and average pore volume decreased, confirming that Ru was well supported.

[Example 3] Preparation of a catalyst in which ruthenium (Ru), gold (Au), palladium (Pd), iron (Fe), and cobalt (Co) are supported on a carrier containing graphite-bonded nitrogen (graphitic-N)

1) Synthesis of graphitic-N-containing carrier

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

2) Preparation of catalysts each supported with ruthenium (Ru), gold (Au), palladium (Pd), iron (Fe) and cobalt (Co)

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

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

1) Synthesis of carrier containing nitrogen of pyrrole bond (pyrrollic-N) and nitrogen of pyridine bond (piridinic-N)

Adenine and magnesium hydrochloride (MgCl ₂ ·6H ₂ O) were put into a mortar in a weight ratio of 1:10 and mixed to obtain a mixture. The resulting mixture was placed in a ceramic boat and calcined under a nitrogen atmosphere for 1 hour to obtain a calcined product. The obtained calcined material was treated with 2 M HCl solution to remove residual magnesium component, 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, C1000A) were synthesized by adjusting the calcination temperature to 800°C and 1000°C. Referring to FIG. 4 , it was confirmed that each of the prepared carriers contained nitrogen in a carbon lattice such as pyrollic-N and piridinic-N. 4 is an analysis result of the carrier by X-ray photoelectron spectroscopy (XPS).

2) Preparation of ruthenium (Ru) supported catalyst

and bpyTN-30-CTF carrier instead of 800 degrees one C800A carrier, the firing temperature to, and the Ru-C800A, and through the same process as in Example 1 except for carrying the RuCl _{3 3} wt% using a 1000 DEG one C1000A carrier Each Ru-C1000A catalyst was prepared.

[Example 5] Gold (Au), palladium (Pd), iron (Fe) and cobalt (Co) on a carrier containing nitrogen of a pyrrole bond (pyrrollic-N) and nitrogen of a pyridine bond (piridinic-N), respectively Supported catalyst preparation

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

[Example 6] Preparation of a catalyst in which ruthenium (Ru) is supported on a titania carrier

1) Synthesis of titania carrier

In an ice bath, 200 ml of 28% aqueous ammonia and 50 ml of titanium isopropoxide were mixed, stirred for 1 hour, filtered with water and ethanol, and vacuum dried at 80° C. to obtain _{Ti(OH) 4 .} The obtained Ti(OH) ₄ 1 g and melamine were mixed, ground with a mortar and calcined at 550° C. for 8 hours to obtain a nitrogen-doped titanium dioxide carrier. At this time, 4 types of titanium dioxide carriers were synthesized by adjusting the amount of melamine to 1 g, 2 g, 3 g, and 4 g. 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 2g of melamine is applied, (c) is 3g of melamine Referring to the narrow spectrum of the N1s peak of the carrier to which this is applied, (d) is the narrow spectrum of the N1s peak of the carrier to which 4 g of melamine is applied) This was 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 put in distilled water, stirred at 100°C for 24 hours, distilled water was removed and then vacuum dried at 100°C for 24 hours to prepare four types of catalysts, respectively.

[Experimental Example 1]

The activities of the catalysts prepared in Examples 1 to 5 were evaluated under the conditions shown in Table 2 below using a high-pressure stirred reactor made of 150 ml stainless steel. Specifically, after Et3N (Triethylamine) was added to the stirred reactor, the catalysts prepared in Examples 1 to 5 were put into the stirred reactor and purged with carbon dioxide to remove air. After the carbon dioxide pressure was set to 40 atm, hydrogen was supplied to maintain the pressure at 80 atm, and then the reaction temperature was raised to 120°C to proceed with the reaction at 120 atm. After obtaining the product obtained through the reaction, 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 molar active metal.

catalyst Catalyst amount (mg) Ru loading (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 compared to the amount of formate produced compared to the amount of catalyst used.

[Example 7]

An Ir-bpyTN-30-CTF catalyst was prepared in the same manner 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 in the same manner as in Example 3 except that IrCl _{3 was used instead of RuCl 3 .}

[Example 10]

An 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 according to the reaction process of Experimental Example 1 and the conditions shown in Table 3 below, and the results are shown in Table 3 below.

catalyst Catalyst amount (mg) Ir loading (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 Ru-supported catalyst had higher activity than the Ir-supported catalyst.

[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 shown in Table 4 below, and the results are shown in Table 4 below.

catalyst Catalyst amount (mg) Ru loading (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 the activity of the catalyst was maintained at the same level even if the metal salt ligand was changed.

[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 shown in Table 5 below, and the results are shown in Table 5 below. At this time, the evaluation was carried out by adding a catalyst prepared using a titanium dioxide carrier (not doped with nitrogen) synthesized with the amount of melamine used as 0 g.

melamine
Usage (g) Firing temperature (degrees) Ru loading (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 nitrogen-doped titanium dioxide support was higher in activity than the nitrogen-doped titanium dioxide support.

[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 using the catalyst prepared in Example 1 under the reaction process of Experimental Example 1 and the conditions shown in Table 6 below, and the results are shown in Table 6 below. 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 among the tertiary amines were used.

[Example 13]

_{RuO(OH) x} -N-TiO _{2 A} catalyst was prepared in the same manner as in Example 6 except that hydrous ruthenium oxide was used instead of RuCl _{3 .} At this time, 2 g of the Ru-supported titanium dioxide carrier is dispersed in 60 ml of an aqueous solution, and a 1 M aqueous NaOH solution is slowly added to the solution so that the pH of the solution is 13.2, stirred for 24 hours, filtered, washed with water and dried. was additionally passed through.

[Example 14]

_{RuO(OH) x} -N-TiO _{2 A} 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, 2 g of the Ir-supported titanium dioxide carrier is dispersed in 60 ml of an aqueous solution, and a 1 M aqueous NaOH solution is slowly added to the solution so that the pH of the solution is 13.2, stirred for 24 hours, filtered, washed with water and dried was additionally passed through.

[Experimental Example 6]

The activity of the catalysts prepared in Examples 13 and 14 was evaluated according to 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, it was confirmed that the catalyst activity was higher when using ruthenium oxide or iridium oxide than _{RuCl 3 .}

[Example 15]

In order to confirm 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, and glass was placed on the upper and lower portions of the catalyst layer. Filled with beads. A preheater was placed at the tip of the reactor. The temperature of the preheater was kept equal to the reaction temperature. Water and Et3N were quantified with a separate liquid transfer pump and introduced into the reactor, and hydrogen was introduced into the reactor by increasing the pressure to the reaction pressure with a compressor. Carbon dioxide maintained in a liquid form in a vessel maintained at 60 atmospheres was introduced into the reactor by a liquid transfer pump, and the carbon dioxide was vaporized before the reaction. The reaction temperature was maintained by a temperature controller and the reaction pressure was maintained by placing a pressure controller at the rear end of the vessel for collecting the reaction product.

The reaction was carried out under these conditions, but _{the reaction was carried out 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. After the reaction was completed, the productivity of formate was evaluated. Thus, it is shown in FIG. 7 .

7(a) shows the productivity of formate according to the reaction temperature under the reaction conditions in which the molar _{ratio of H 2} /CO ₂ of 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. , and it was confirmed that the productivity of formate increased as the reaction temperature increased. Specifically, at a reaction temperature of 140°C 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 these reaction conditions.

7(b) shows the productivity of formate according to the reaction pressure under the reaction conditions in which the molar _{ratio of H 2} /CO ₂ of 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.

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

7 (d) shows a reaction temperature of 120 degrees and a reaction pressure of 120 atm. In the _{reaction conditions, the molar ratio of H 2} /CO ₂ of the feed solution is 1.0 and the concentration of Et3N is 3M. While changing the molar ratio of _{Et3M/CO 2 CO} 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 was 43.6%, and the productivity of formate was 650 gHCOOH/gcat/d.

On the other hand, 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. As a result of the analysis, almost no carbon monoxide was detected, and it was confirmed that the selectivity of formate reached almost 100%.

[Example 16]

as shown in FIG. 8 In order to confirm the catalyst 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 had a diameter of 1 inch and a length of 30 cm. In addition, the tube used a tubular band heater to control the temperature. The reactor was filled with Et3N with a gas sparger preventing liquid from entering the bottom of the reactor. At a reaction temperature of 120 degrees and a reaction pressure of 120 atm, 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, respectively.

After completion of the reaction, 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. As a result of the analysis, 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 (syngas) through the process diagram as shown in FIG. 9 .

Specifically, methane (3,196.8 kg/h) and steam (12,603 kg/h) were supplied and reacted to the methane reforming reactor (R2) maintained at 850 degrees and 20 atm. After the reaction, heat was recovered from the product through a heat exchanger, and again under the conditions of 450 degrees and 20 atmospheres, methane (184.0 kg/h), carbon monoxide (3398.3 kg/h), carbon dioxide (2979.3 kg/h), hydrogen (1267.3 kg) /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 degrees and a low temperature water gas reactor at 210 degrees (R4), and through this reaction, methane (184.0 kg / h), carbon monoxide (71.5 kg / h), carbon dioxide (8208 kg/h), hydrogen (1504.6 kg/h) and steam (5840 kg/h) was produced. This water gas composition (stream (3)) was pressurized from 20 atm to 120 atm by a compressor to remove water, and then was supplied to the formate generating reactor (R1).

_{On the other hand, the CO 2} absorbed product (stream (7)) supplied from the carbon dioxide absorption tower (A) _{is a composition of CO 2} (25080 kg/h), Et3N (95725 kg/h) and water (183412 kg/h). It was supplied to the formate generation 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 (2745 kg/h) contained in the gas stream (2745 kg/h) are formate. It was circulated to the production reactor (R1). As a result, stream (3), stream (7) and stream (4) were supplied to the formate generating reactor (R1).

400 kg of the catalyst Ru-bpyTN-30-CTF prepared in Example 1 was filled in the formate generating reactor (R1), 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) (Stream (5)) was discharged. Here, the amount of formic acid was calculated through the amount of an adduct in which formate and Et3N were combined. Specifically, the addition compound is Et3NH ⁺ :HCOO ^- (1:0.81), and 1:0.81 in parentheses indicates the molar ratio of ^{Et3NH + to HCOO -} in the addition compound.

The reactant (Stream (5)) was maintained at a temperature of about 80°C with gas-liquid separation in vessel GL. Among the separated components, the gas was refluxed to the formate generation reactor (R1), and ^{131056 kg/h of an addition compound of Et3NH +} :HCOO ^- (1:0.81) and 186333 kg/h of water were supplied to the evaporation tower (Ev). The evaporation tower (Ev) was 1.2 m in height and filled with a lash ring, and the pressure was maintained at 150 mmHg. A stream having a composition of 186333 kg/h of water and 61934 kg/h of Et3N was discharged from the top of the evaporation tower (Ev), and from the bottom of the evaporation tower (Ev), Et3NH ⁺ :HCOO ^- (1:2.3) adduct (formic acid 35331) kg/h and Et3N 33791 kg/h were obtained). Et3N and water discharged from the upper part of the evaporation column (Ev) are phase-separated, and they are mixed in a vessel (V4) together with Et3N 33791 kg/h discharged from the upper part of the distillation column (D1) and phase-separated, respectively, to the Feed tank (T1) and It was supplied to the feed tank (T2). Here, the distillation column (D1) has a height of 2.5 m and is filled with structured packing. After that, Et3N and water (Stream (6)) were supplied to the carbon dioxide absorption tower (A), and the carbon dioxide contained in the combustion flue gas was absorbed in the carbon dioxide absorption tower (A) as a product (stream (7)) _{from which the CO 2 was absorbed.} , was recycled to the formate generating reactor (R1).

^{On the other hand, Et3NH +} :HCOO ^- (1:2.3) added compound discharged from the bottom of the evaporation tower (Ev) was supplied to the storage vessel (V2), and nBIMH ⁺ :HCOO ^- ( 1:0.18) was mixed with 124067 kg/h of an additional compound to form a mixture, and the formed mixture (stream (10)) was supplied to the distillation column (D1). Here, 1:0.81 in parentheses indicates ^{the molar ratio of nBIMH + to HCOO −} in the additional compound, and nBIM indicates n-butylimidazole.

Then, Et3N 33791 kg/h was discharged from the upper part of the distillation column (D1), and 159398 kg/h of nBIMH ⁺ :HCOO ^- (1:1) adduct compound was discharged from the lower part, and the adduct compound was stored in the storage container (V3). . The nBIMH+:HCOO-(1:1) addition compound (stream (11)) stored in the storage container (V3) was supplied to the purification tower (D2) and subjected to purification. After the purification process, 35331 kg/h of pure formic acid was discharged from the upper part of the refinery column (D2), and 124067 kg/h of nBIMH ⁺ :HCOO ^- (1:0.18) adduct was discharged from the lower part of the refinery column (D2). and it was recycled to the storage vessel (V2).

100: water gas conversion unit
200: formate generation unit
300: formic acid separation unit
400: carbon dioxide collecting unit
500: gas-liquid separation unit

Claims (16)

a process of supplying syngas to a water gas conversion unit to convert carbon monoxide contained in syngas into hydrogen and carbon dioxide;
supplying a mixed gas containing hydrogen and carbon dioxide converted in the water gas conversion unit to a formate generating unit equipped with a catalyst to generate a formate;
supplying the formic acid salt to a formic acid separation unit to separate formic acid; and
supplying combustion exhaust and an amine compound to a carbon dioxide collecting unit to produce a carbonate-amine adduct,
The carbonate-amine addition compound is supplied to the formate generator,
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. delete According to claim 1,
The carbonic acid-amine addition compound is supplied to the formic acid 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. According to claim 1,
The amine-based compound is a compound represented by the following formula (1) The manufacturing process of formic acid:
[Formula 1]
NR ₁ R ₂ R ₃
In Formula 1,
R ₁ to R ₃ are the same or different from each other, and are 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 combine with 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-based compound is trimethylamine, triethylamine, tripentylamine, tripropylamine, tributylamine, trihexylamine, N,N- Dimethylbutylamine (N,N-dimethylbutylamine), dimethylcyclohexylamine (dimethylcyclohexylamine), dimethylphenethylamine (dimethylphenethylamine) and isoamylamine (isoamylamine) at least one selected from the group consisting of a manufacturing process of formic acid. According to claim 1,
The amine-based compound is dialkylpiperazine (N,N-dialkyl piperazine), morpholine (morpholine), alkylmorpholine (N-alkyl morpholine), alkylpiperidine and alkylpyrrolidine (alkylpyrrolidine) from the group consisting of A process for producing formic acid that is one or more selected. According to claim 1,
A process for producing formic acid in which a separate carbon dioxide is additionally supplied together with the mixed gas to the formate generator. According to claim 1,
The catalyst provided in the formate generating 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 includes at least one selected from the group consisting of iridium (Ir), ruthenium (Ru), palladium (Pd), gold (Au), iron (Fe) and cobalt (Co). . 9. The method of claim 8,
The porous carrier includes porous organic frameworks, covalent organic frameworks, covalent triazine frameworks, porous aromatic frameworks, and porous organic polymers. Organic polymer), the manufacturing process of formic acid comprising 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 comprising a triazine (triazine) structure or a heptazine (heptazine) structure. 9. The method of claim 8,
The porous carrier is one selected from the group consisting of nitrogen of a pyridine bond (pyridinic-N), nitrogen of a pyrrole bond (pyrrolic-N), nitrogen of a pyrazole bond (pyrazole-N), and nitrogen of a graphite bond (graphitic-N) A process for producing formic acid comprising more than one species. 9. The method of claim 8,
The porous carrier is a process for producing formic acid comprising at least one selected from the group consisting of titania, alumina, gallia, zirconia and silica in which nitrogen or phosphorus is contained in the framework structure. Water gas conversion unit for converting carbon monoxide contained in the synthesis gas into hydrogen and carbon dioxide by the water gas reaction of the synthesis gas;
a formate generator for generating a formate by reacting the mixed gas containing hydrogen and carbon dioxide with an amine compound in the presence of a catalyst;
a formic acid separation unit for separating formic acid from the formic acid salt; and
and a carbon dioxide trapping unit that reacts the combustion exhaust with an amine compound to produce a carbonate-amine adduct,
The carbonate-amine addition compound is supplied to the formate generator,
The synthesis gas is an apparatus 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. delete 15. The method of claim 14,
The formic acid producing unit is an apparatus for producing formic acid comprising 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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