KR101282735B1 - Preparing method of nitroparaffin by gas-phase nitration using solid base catalyst - Google Patents

Abstract

The present invention relates to a process for producing nitroparaffins in high yield by gas phase nitration of a C _{1 to} C ₄ hydrocarbon gas under a specific solid base catalyst with a nitrating agent gas.

Description

Preparation method of nitroparaffin by gas phase nitration using solid base catalyst {Preparing method of nitroparaffin by gas-phase nitration using solid base catalyst}

The present invention relates to a process for producing nitroparaffins in high yield by gas phase nitration of a C _{1 to} C ₄ hydrocarbon gas under a specific solid base catalyst with a nitrating agent gas.

Nitroparaffins have been used as components of solvent mixtures to provide physical property enhancements to the coatings industry. Nitroparaffins are still useful compounds for a variety of applications in high value-added applications such as intermediates in compound synthesis, solvents in separation processes, chemical stabilizers, fuel components, and water substitution from metal surfaces.

As a general method for producing nitroparaffins, a gas-phase production method for producing nitroparaffins by nitrifying a hydrocarbon compound with nitrous acid gas (NO ₂ ) is widely known. Since the nitroparaffin manufacturing process is performed under high temperature conditions in the range of 50 to 800 ° C. and high pressure in the range of 70 to 110 atm, the risk is large, and thus there is a limit to applying the continuous process. In addition, there is a disadvantage that the high pressure reactor equipment cost used to maintain the high pressure condition is expensive. Nitroparaffin production method disclosed in International Patent Publication No. WO 2009/129099 also proceeds with the nitration reaction under high temperature and high pressure conditions, there is a disadvantage that the process must be limited by a batch process rather than a continuous process.

Therefore, there is an urgent need to develop a method for producing nitroparaffins by gas-phase nitration and to efficiently produce nitroparaffins under milder reaction conditions.

It is an object of the present invention to provide an improved process for the preparation of nitroparaffins which facilitates the gas phase nitration reaction even under low pressure conditions around ambient pressure using certain solid base catalysts.

Another object of the present invention is to provide a method for preparing nitroparaffin, which proceeds in a continuous process as well as in a batch process.

In order to solve the above problems, the present invention is a C _{1 ~} C ₄ of the solid base catalyst of a metal oxide containing at least one metal selected from Ca, Mg and Zn It is characterized by a method of producing nitroparaffins by gas phase nitration reaction of a hydrocarbon and a nitrating agent gas.

In addition, the present invention is based on a metal oxide containing at least one metal selected from Ca, Mg and Zn as a support under a solid base catalyst of a metal-supported oxide supported on at least one crude active metal selected from K, Mg and Cr, Of C _{1 to} C ₄ It is characterized by a method of producing nitroparaffins by gas phase nitration reaction of hydrocarbon and nitrous acid gas (NO ₂ ).

The present invention has the effect of efficiently performing the gas phase nitration reaction even under low pressure conditions around atmospheric pressure by using a specific solid base catalyst.

In addition, the nitroparaffin manufacturing method of the present invention is carried out in a low pressure condition around the atmospheric pressure, there is an effect that can be carried out in a continuous process as well as a batch process of gas phase nitration.

The present invention relates to a method for preparing nitroparaffins by gas phase nitration reaction under mild reaction conditions using a specific solid base catalyst and using hydrocarbon gas and nitrite gas as reactants. That is, the present invention is characterized by the use of a specific solid base catalyst as a catalyst for the gas phase nitration reaction for the production of nitroparaffins.

The solid base catalyst used in the present invention may be a metal oxide catalyst of CaO, MgO, ZnO, CaMgO, CaZnO, MgZnO, or CaMgZnO, or at least one crude selected from K, Mg, and Cr using the metal oxide as a support. It may be a metal supported oxide catalyst on which an active metal is supported.

In the case of the solid base catalyst of the metal-supported oxide, since the base strength of the surface of the catalyst can be further increased by the supported active metal, it is possible to obtain an effect of further enhancing the catalytic activity as a solid base catalyst. In fact, according to the embodiment of the present invention, it can be seen that the catalytic activity of about 3 to 7% of the metal-supported oxide catalyst on which the crude active metal is supported is increased compared to the metal oxide catalyst.

As the solid base catalyst of the metal-supported oxide, the metal-supported oxide on which one crude active metal is supported specifically includes K-CaO, Mg-CaO, Cr-CaO, K-MgO, Mg-MgO, Cr-MgO, K- ZnO, Mg-ZnO, Cr-CaMgO, K-CaMgO, Mg-CaMgO, Cr-CaMgO, Cr-CaMgO, K-CaZnO, Mg-CaZnO, Cr-CaZnO, K-MgZnO, Mg-MgZnO, Cr-M K-CaMgZnO, Mg-CaMgZnO, Cr-CaMgZnO, and the like may be included.

Metal-supported oxide carrying two or more crude active metals may be uniformly distributed in two or more crude active metals, or each of the crude active metals may be formed by forming a separate coating layer to form a plurality of coating layers. have.

The metal supported oxide catalyst in which two or more crude active metals are distributed in a single coating layer is specifically K, Mg-CaO, K, Cr-CaO, Mg, Cr-CaO, K, Mg, Cr-CaO, K, Mg-MgO, K, Cr-MgO, Mg, Cr-MgO, K, Mg, Cr-MgO, K, Mg-ZnO, K, Cr-ZnO, Mg, Cr-ZnO, K, Mg, Cr-ZnO, K, Mg- CaMgO, K, Cr-CaMgO, Mg, Cr-CaMgO, K, Mg, Cr-CaMgO, K, Mg-CaZnO, K, Cr-CaZnO, Mg, Cr-CaZnO, K, Mg, Cr-CaZnO, K, Cr-MgZnO, Mg, Cr-MgZnO, K, Mg, Cr-MgZnO, K, Cr-CaMgZnO, Mg, Cr-CaMgZnO, K, Mg, Cr-CaMgZnO and the like.

The metal-supported oxide catalyst having a core-shell structure in which two or more crude active metals form a coating layer is specifically K / Mg-CaO, Mg / K-CaO, K / Cr-CaO, Cr / K-CaO, Mg / Cr-CaO, Cr / Mg-CaO, K / Mg / Cr-CaO, K / Cr / Mg-CaO, Mg / K / Cr-CaO, Mg / Cr / K-CaO, Cr / K / Mg-CaO, Cr / Mg / K-CaO, and the like may be included. Although only CaO is exemplified as the metal oxide support, the core-shell structure is used even when the metal oxide used as the support is MgO, ZnO, CaMgO, CaZnO, MgZnO, or CaMgZnO. The metal supported oxide catalyst is also included in the scope of the present invention. In addition, the present invention places no particular limitation on the supporting and coating order of the crude active metal supported or coated on the metal oxide support. In addition, the 'Cr / Mg / K-CaO catalyst' exemplified as a metal-supported oxide catalyst having a core-shell structure has a CaO support loaded with potassium (K) as a core, and a magnesium (Mg) metal A coating layer and a chromium (Cr) metal coating layer are sequentially coated to form a core-shell structured metal-supported oxide catalyst.

On the other hand, the present invention is not particularly limited to the above-described method for producing a solid base catalyst.

As a typical manufacturing method, a solid base catalyst of a metal oxide of CaO, MgO, ZnO, CaMgO, CaZnO, MgZnO, or CaMgZnO may be prepared by mixing and firing at least one precursor compound containing a metal of Mg, Ca, or Zn. have. The metal precursor compound is a compound commonly used in the field of catalyst production, specifically, chlorides, hydroxides, sulfides, nitrates, carbonates, sulfates, acetates, etc. of the metals may be used. Specifically, the metal precursor compound is Mg (NO ₃ ) ₂ · 6H ₂ O, MgCO ₃ , MgCl ₂ · 6H ₂ O, Mg (OH) ₂ , Ca (NO ₃ ) ₂ , Ca (NO ₂ ) ₂ , CaCl ₂ , CaCO ₃ , Ca (OH) ₂ , Zn (NO ₃ ) ₂ · 6H ₂ O, Zn (NO ₃ ) ₂ , ZnCO ₃ , ZnCl ₂ , Zn (OH) _2, and the like. The firing temperature is in the range of 500 ° C to 1000 ° C, preferably in the range of 500 ° C to 900 ° C. If the firing temperature is too low, there may be a problem in that a solid base catalyst is not produced. There may be a problem that the activity of.

The production method of the solid base catalyst of the metal-supported oxide is a supported catalyst production method commonly used in the field of catalyst production. For example, a precipitation method, a supporting method, an impregnation method, and the like can be used.

A typical method for preparing a solid base catalyst of a metal supported oxide includes the following series of processes. For example, preparing a crude active metal precursor solution by dissolving the precursor compound of the crude active metal in distilled water; Adding a metal oxide to the crude active metal precursor solution and heating and stirring; And filtering and drying the metal oxide on which the crude active metal is supported to obtain a metal supported oxide. The crude active metal precursor compound may also be used as a compound commonly used in the field of catalyst production, specifically, chloride, hydroxide, sulfide, nitrate, carbonate, sulfate, acetate, etc. of the metal. In the present invention, one or more crude active metal precursor compounds may be used in the preparation of the crude active metal precursor solution. In addition, the series of crude active metal supporting processes described above may be repeated two or more times.

When the gas phase nitration reaction is performed using the solid base catalyst described above, nitroparaffin can be produced in high yield even under low pressure and low temperature reaction conditions.

The hydrocarbon compound used as a reactant in the method for producing nitroparaffin of the present invention is a gaseous hydrocarbon compound consisting of a linear hydrocarbon ring having 1 to 4 carbon atoms, a crushed hydrocarbon ring, a saturated hydrocarbon ring, or an unsaturated hydrocarbon ring. An unsaturated hydrocarbon ring refers to a hydrocarbon ring containing one or more double bonds or triple bonds.

In the present invention, nitrous acid gas (NO ₂ ), dinitrogen tetraoxide gas (N ₂ O ₄ ), nitric acid gas (HNO ₃ ), or the like may be used as the nitrating agent gas for nitrating the hydrocarbon compound.

In the case of nitrous acid gas (NO ₂ ) used as a nitrating agent in the embodiment of the present invention, nitric acid and sulfur are mixed in a volume ratio of 5 to 15: 0.5 to 6, preferably 8 to 10: 2 to 4, and 120 to 170 It manufactured and used by heating to ° C. Production of nitrous acid (NO ₂ ) gas In order to prevent moisture from entering the reactor, a cooling trap may be installed to remove moisture. The prepared nitrous acid gas (NO ₂ ) flowed into the reactor together with the hydrocarbon compound to proceed the gas phase nitration reaction. The effect of improving the yield of the production can be expected.

In the gas phase nitration reaction of the present invention, a hydrocarbon compound and a nitrating agent are specifically used in a 1: 0.5 to 30 volume ratio, preferably 1: 10 to 20 volume ratio, and the reaction pressure is specifically 0 to 1.5 as the ambient pressure. The nitrification reaction is carried out for 1 to 200 hours, preferably for 1 to 100 hours, while maintaining the atm pressure range and maintaining the temperature range of 100 to 500 ° C, preferably 250 to 400 ° C.

That is, the conventional gas phase nitroparaffin manufacturing method had to be maintained under high pressure and high temperature conditions, when using the solid base catalyst proposed by the present invention to produce nitroparaffin with excellent yield even if the relatively low temperature is maintained at atmospheric pressure conditions can do. Therefore, the nitroparaffin manufacturing method of the present invention can proceed the gas yarn nitration reaction in a continuous process as well as a batch process.

The present invention will now be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Preparation Example Preparation of Solid Base Catalyst

Preparation Example 1 Preparation of MgO Catalyst

Mg (NO ₃ ) ₂ .6H ₂ O was prepared by calcining at 600 ° C. for 3 hours.

Preparation Example 2 Preparation of ZnO Catalyst

After dissolving 33.84 g of Zn (NO ₃ ) ₂ · 6H ₂ O in 150 mL of H ₂ O, slowly adding dropwise ammonia solution (28-30%, SAMCHUN) as a precipitant to adjust the pH to 8-9, to form a precipitate. After washing three times with H ₂ O, dried in an oven at 110 ℃, it was prepared by firing in an oven at 600 ℃ for 3 hours.

Preparation Example 3 Preparation of CaO Catalyst

Dissolve 15.37 g of CaCl _{2 in} 150 ml of H2O, and slowly add dropwise ammonia solution (28-30%, SAMCHUN) as a precipitant to adjust pH to 8-9 to generate a precipitate, and then wash three times with H ₂ O. After drying in an oven at 110 ℃, it was prepared by firing in an oven at 600 ℃ for 3 hours.

Preparation Example 4 Preparation of Cr-CaO Catalyst

After dissolving 3.85 g of Cr (NO ₃ ) ₃ 9H ₂ O as a precursor of Cr in 50 ml of distilled water, 4.5 g of CaO support was added to the solution, and stirred briefly at 70 ° C. for 3 hours. Then, the reaction was washed three times with H ₂ O and dried in an oven at 100 ℃ to prepare a Cr-CaO catalyst supported Cr on a CaO support.

Preparation Example 5 Preparation of Cr / K-CaO Catalyst

0.95 g of KCl as a precursor of K was dissolved in 50 ml of distilled water, and then 4.5 g of CaO support was added to the solution, and stirred at 70 ° C. for 3 hours. Then, the reactants were washed three times with H ₂ O and dried in an oven at 100 ° C. to prepare K-CaO loaded with K on a CaO support.

Then, 3.85 g of Cr (NO ₃ ) ₃ 9H ₂ O was dissolved in 50 ml of distilled water as a precursor of Cr, and then 4.5 g of K-CaO prepared above was added to the solution and stirred at 70 ° C. for 3 hours. It was. Then, the reactant was washed three times with H ₂ O and dried in an oven at 100 ° C. to form K-CaO as a core, and a core-shell structure having a potassium (K) coating layer formed on an outer surface thereof. Cr / K-CaO catalysts were prepared.

Preparation Example 6 Preparation of Cr / Mg-CaO Catalyst

After dissolving 5.27 g of Mg (NO ₃ ) ₂ 6H ₂ O as a precursor of Mg in 50 ml of distilled water, 4.5 g of CaO support was added to the solution, and stirred briefly at 70 ° C. for 3 hours. Then, the reaction was washed three times with H ₂ O and dried in an oven at 100 ℃ to prepare Mg-CaO supported Mg on a CaO support.

Then, 3.85 g of Cr (NO ₃ ) ₃ 9H ₂ O was dissolved in 50 ml of distilled water as a precursor of Cr, and then 4.5 g of Mg-CaO prepared above was added to the solution and stirred at 70 ° C. for 3 hours. It was. Then, the reaction was washed three times with H ₂ O and dried in an oven at 100 ℃ Mg-CaO as a core (core), the core-shell structure of the chromium (Cr) coating layer formed on the outer surface Cr / Mg-CaO catalysts were prepared.

Preparation Example 7 Preparation of K / Cr-CaO Catalyst

After dissolving 3.85 g of Cr (NO ₃ ) ₃ 9H ₂ O as a precursor of Cr in 50 ml of distilled water, 4.5 g of CaO support was added to the solution and stirred for 3 hours at 70 ° C. Then, the reactants were washed three times with H ₂ O and dried in an oven at 100 ° C. to prepare Cr-CaO supported Cr on a CaO support.

Then, 3.85 g of KNO ₃ as a precursor of K was dissolved in 50 ml of distilled water, and then 4.5 g of Cr-CaO prepared above was added to the solution, and stirred at 70 ° C. for 3 hours. Then, the reactants were washed three times with H ₂ O and dried in an oven at 100 ° C. to form Cr-CaO as a core, and a core-shell structure having a potassium (K) coating layer formed on its outer surface. K / Cr-CaO catalysts were prepared.

Preparation Example 8 Preparation of CaMgO Catalyst

17.69 g of Mg (NO ₃ ) ₂ · 6H ₂ O and 7.69 g of CaCl ₂ were dissolved in 150 ml of H ₂ O, and then slowly added dropwise to the ammonia solution (28-30%, SAMCHUN) as a precipitant to adjust to pH 8-9. A precipitate was produced, washed three times with H ₂ O, dried in an oven at 110 ° C., and calcined in an oven at 600 ° C. for 3 hours.

Preparation Example 9 Preparation of CaZnO Catalyst

16.92 g of Zn (NO ₃ ) ₂ · 6H ₂ O and 7.69 g of CaCl ₂ were dissolved in 150 mL of H ₂ O, and then slowly added dropwise to the ammonia solution (28-30%, SAMCHUN) to adjust the pH to 8-9. A precipitate was produced, washed three times with H ₂ O, dried in an oven at 110 ° C., and calcined in an oven at 600 ° C. for 3 hours.

Preparation Example 10 Preparation of MgZnO Catalyst

_{Zn (NO 3) 2 · 6H} 2 O 16.92 g, Mg (NO 3) 2 · 6H 2 O 17.69 g after which the precipitation agent is ammonia solution dissolved in _{H 2 O 150 ㎖ (28~30%} , SAMCHUN) was slowly added dropwise The mixture was adjusted to pH 8-9 to produce a precipitate, washed three times with H ₂ O, dried in an oven at 110 ° C., and then calcined in an oven at 600 ° C. for 3 hours.

EXAMPLES Preparation of Nitroparaffins

This example illustrates a representative method for preparing nitroparaffins by performing gas acid nitration reaction using the solid base catalyst prepared in Preparation Example.

Examples 1-11. Preparation of Nitropropane

To generate nitrous acid gas (NO ₂ ), 1 kg of nitric acid and 40 g of sulfur were added thereto, and the mixture was heated to 150 ° C. while stirring using a magnetic bar. After filling 0.2 g of each of the solid base catalysts prepared in Preparation Examples 1 to 10 in a separate reactor, propane gas and nitrous acid gas (NO ₂ ) produced above were put together in the reactor. In order to determine the yield of nitroparaffin according to the reaction temperature was carried out by changing the reaction temperature from 250 ℃ to 400 ℃. Gas chromatography was used for analysis of the reaction product obtained under each reaction temperature, and the results are shown in Table 1 below.

Comparative Example. Preparation of Nitropropane

Nitropropane was prepared in the same manner as in Example, except that the nitration reaction was performed under the absence of a catalyst. The results are shown in Table 1 below.

division
catalyst Reaction pressure
(ATM) Reaction temperature
(℃) Propane
Conversion rate
(%) Yield (%) 1-nitropropane 2-nitropropane

Example 1

MgO One 300 36.4 6.2 24.5 One 325 55.8 9.8 35.2 One 350 68.6 12.5 40.3 One 375 75.8 10.9 38.1 One 400 77.3 8.5 31.6

Example 2

ZnO One 300 32.1 5.9 23.1 One 325 51.7 8.4 32.6 One 350 68.3 14.6 41 One 375 73.4 11.3 37.5 One 400 75.8 8.8 30.2

Example 3

CaO One 300 26.4 5.1 18.9 One 325 46.9 8.9 31.2 One 350 65.3 11.8 41.5 One 375 70.9 11.9 41.1 One 400 72.7 7.8 31.2
Example 4
CaMgO One 200 38.1 8.4 21.4 One 250 66.4 12.7 39.3 One 300 74.5 15.2 44.8
Example 5
CaZnO One 200 37.8 9.1 20.1 One 250 65 11.8 37.2 One 300 76.5 18.6 45.8
Example 6
MgZnO One 200 42.6 10.8 25.1 One 250 67.2 13.8 40.3 One 300 77.7 16.6 47.3
Example 7
Cr-CaO One 200 40.7 8.8 22.2 One 250 66.4 13.3 36.5 One 300 79.6 18.4 48.4
Example 8
Cr / K-CaO One 200 42.5 9.7 28.4 One 250 69.4 10.1 38.7 One 300 80.3 19.7 51.1
Example 9
Cr / Mg-CaO One 200 37.8 8.6 23.3 One 250 55.3 11.7 30.6 One 300 65.5 13.3 38
Example 10
K / Cr-CaO One 200 46.9 9.8 25.1 One 250 59.2 13.2 34.7 One 300 71.7 16.4 43.8
Example 11
K / Cr-CaMgO One 200 38.4 7.9 21.3 One 250 60.8 14 35.8 One 300 73.7 15.7 44.5
Comparative Example
No catalyst One 250 21 4.5 13 One 300 22 5.6 15 One 325 23 5.5 14 One 350 25 4.7 10

According to the results of Table 1, when the nitration reaction of propane under the conditions using the solid base catalyst of the present invention, the conversion rate of propane gradually increased as the temperature was increased.

In the reaction using a solid base catalyst of a metal oxide selected from CaO, MgO and ZnO (Examples 1 to 3), the yield of nitropropane was the highest at the reaction temperature of 325 to 375 ° C. The yield of nitropropane was found to decrease rather. In addition, in the reaction using solid base catalysts of complex metal oxides such as CaMgO, CaZnO, and MgZnO (Examples 4 to 6), the yield of nitro compounds as well as the conversion of propane were highest at the reaction temperature of 250 to 300 ° C. That is, when the solid base catalyst of the composite metal oxide is used as compared to the solid base catalyst of the single metal oxide, the effect of lowering the reaction temperature can be expected.

In addition, in the reaction using a solid base catalyst of a metal-supported oxide in which a crude active metal such as K, Mg and Cr was supported on a support of CaO metal oxide (Examples 7 to 11), the yield of nitropropane was the highest at 300 ° C. . Compared with the nitration reaction under CaO metal oxide catalyst (Example 3), the yield increase effect of up to 400% was obtained under the same temperature conditions, and even if the reaction temperature was lowered to 250 ° C, nitroparaffins were obtained in the same yield as in Example 3. You can get it. In addition, in the reaction using a K / Cr-CaMgO catalyst using a CaMgO composite metal oxide as a support (Example 11), a K / Cr-CaO catalyst using a single metal oxide of CaO as a support (Example 10) Compared with), not only propane conversion but also nitro compound yield are improved. Therefore, when the solid base catalyst of the present invention is constituted by appropriately combining the support of the metal oxide and the crude active metal, it can be used as a catalyst for nitroparaffin production and excellent activity can be expected.

In addition, when the nitration reaction was performed under a catalyst (comparative example), the yield was very low.

As described above, the nitroparaffin manufacturing method in the presence of the solid base catalyst proposed by the present invention was able to obtain nitroparaffin in a sufficiently high yield even when the gas phase nitration reaction was carried out at atmospheric pressure, and in particular, a batch process as well as a continuous process. As the reaction can be advanced, the use value is high as an industrial production method.

Claims (7)

Of C _{1 to} C ₄ In the method for producing nitroparaffin by performing a gas phase nitration reaction with a hydrocarbon gas and nitrite gas,
The gas phase nitration reaction is based on a metal oxide containing at least one metal selected from Ca, Mg and Zn as a support, and a metal supported oxide on which at least one crude active metal selected from K, Mg and Cr is supported. a core and having a core-shell structured solid base catalyst in which a shell is formed by a coating layer containing K or Cr on the outer surface of the core. Nitroparaffin production method characterized in that carried out at 250 to 400 ℃ reaction temperature conditions.
delete The method of claim 1,
The metal oxide containing at least one metal selected from Ca, Mg, and Zn is CaO, MgO, ZnO, CaMgO, CaZnO, MgZnO, or CaMgZnO.
delete The method of claim 1,
The gas phase nitration reaction is a method for producing nitroparaffin, characterized in that carried out in a continuous process or batch process.
The method of claim 1,
The hydrocarbon gas and the nitrous acid gas is a method for producing nitroparaffin, characterized in that used in the range of 1: 5 to 30 by volume. delete