KR100324872B1 - A process for preparing Acrolein - Google Patents

Abstract

The present invention relates to a method for producing acrolein, and more particularly, to a method for producing acrolein in a high yield by oxidizing propylene under a solid catalyst having a core-shell structure represented by the following formula (1).

[Bi _n A _a O _x ] [(100-z)% Fe _f Ni _g Mo _m O _y + z% SiO ₂ ]

In Formula 1 above:

A is at least one element selected from boron, phosphorus and molybdenum;

When m is 1, n is 0.001-3, a is 0.001-3, f is 0.01-5, g is 0.1-5, z is 0-90,

x and y are values that are set to match valences by other components in the core and shell parts.

Description

A process for preparing Acrolein

The present invention relates to a method for producing acrolein, and more particularly, to a method for producing acrolein in a high yield by oxidizing propylene under a solid catalyst having a core-shell structure represented by the following formula (1).

Formula 1

[Bi _n A _a O _x ] [(100-z)% Fe _f Ni _g Mo _m O _y + z% SiO ₂ ]

In Formula 1 above:

A is at least one element selected from boron, phosphorus and molybdenum;

When m is 1, n is 0.001-3, a is 0.001-3, f is 0.01-5, g is 0.1-5, z is 0-90,

x and y are values that are set to match valences by other components in the core and shell parts.

Acrolein is used as a basic raw material for various acrylates, and is also a raw material for fine chemical products widely used in textile processing, paper processing, coating, adhesives, leather processing, and the like. The demand for such acrolein is continuously increasing with the development of polymerization technology, and its use is also steadily being developed.

Acrolein was first synthesized by high temperature decomposition of glycerin in 1843, and the first synthesis of acrylic acid by vapor phase oxidation of acrolein. Since then, as a method for synthesizing acrolein, techniques such as acetylene method using nickel, ethylene method using palladium, and hydrolysis of acrylonitrile with sulfuric acid have been developed. The process is an oxidation reaction with propylene as the starting material. In addition, as part of the C1 chemistry, research is being actively conducted on the aldol condensation method by the condensation reaction of formaldehyde and acetic acid.

Among the above methods, the oxidation of propylene is generally performed to produce acrolein using a Bi-Mo-O based composite oxide catalyst at about 400 ° C.

In Korea, LG has introduced Nippon Shokubai process to produce acrolein, which uses Bi-Mo-Fe-Co-O based composite oxide catalyst and reacts under a reaction temperature of 325 ℃ and under pressure of 2.5 ~ 3.0 atm. It is characterized by generating.

On the other hand, as the importance of catalyst selection in the olefin oxidation reaction using a catalyst has been raised, many research results related to the catalyst have been reported so far, and the most distinctive feature is not only in the reaction process but also in the composition and preparation of the catalyst. It is emerging from development. As a result, acrylic acid yields of 90% or more in the oxidation reaction and acrylonitrile in the ammonia oxidation reaction, which is one of the similar reactions, have been improved in yields of about 80% or more in commercial plants. Ammonia oxidation requires higher temperatures (400-480 ° C) than in normal oxidation reactions (320-380 ° C), which is the chemical adsorption of propylene to the catalyst irreversibly at low temperatures and reversibly at high temperatures. It is reported because it prevents the point.

Accordingly, the present inventors have disclosed a core-shell structured solid catalyst useful for preparing nitrile compounds by ammonia oxidation of olefins in Korean Patent Application No. 98-4340. In more detail, the Bi ₂ O ₃ -MoO ₃ series catalyst is known to exhibit high activity in the synthesis of nitrile compounds by ammonia oxidation of olefins. The basic technical idea is that there is a big difference in activity. That is, at least one selected from bismuth, boron, phosphorus and molybdenum using molybdenum, iron, nickel, and silicon as active ingredients, forming a core catalyst phase by a slurry method, and introducing an impregnation method therein. It is characterized by a new core-shell structured solid catalyst which allows the formation of the shell catalyst phase which is based on the element. In addition, it was confirmed through the activity comparison test that the solid catalyst of the core-shell structure has superior catalytic activity than the catalyst made by the conventional method.

Here, the present inventors do not only apply the core catalyst of the core-shell structure shown in Korean Patent Application No. 98-4340 to ammonia oxidation to prepare a nitrile compound, and the catalyst is used for other purposes, that is, oxidize propylene. It was conceived that the reaction could produce acrolein in high yield. Therefore, the inventors of the present invention disclosed in the Republic of Korea Patent Application No. 98-4340 to prepare a nitrile compound, the present invention is to produce acrolein in a high yield by oxidizing propylene, there is a difference in its use will be. In addition, since ammonia is not used in the oxidation reaction, the reaction occurs easily at a lower temperature than the ammonia oxidation reaction, and it is known that the reaction can be performed by a simpler reaction mechanism.

Accordingly, an object of the present invention is to provide a method for producing acrolein in a high yield by oxidizing propylene under a solid catalyst of a core-shell structure shown in Korean Patent Application No. 98-4340.

The present invention is a method for producing acrolein by oxidizing propylene, the oxidation reaction has a core portion [(100-z)% Fe _f Ni _g Mo _m O _y + z% SiO ₂ ] composition, the shell portion It is characterized by a method for producing acrolein which is carried out under a solid catalyst having a core-shell structure represented by the following Chemical Formula 1 having _a [Bi _n A _a O _x ] composition.

Formula 1

[Bi _n A _a O _x ] [(100-z)% Fe _f Ni _g Mo _m O _y + z% SiO ₂ ]

In Formula 1 above:

A is at least one element selected from boron, phosphorus and molybdenum;

When m is 1, n is 0.001-3, a is 0.001-3, f is 0.01-5, g is 0.1-5, z is 0-90,

x and y are values determined to match valences in the core and shell portions, respectively.

Referring to the present invention in more detail as follows.

The present invention relates to a process for producing acrolein in high yield by oxidation of propylene under a solid catalyst having a core-shell structure.

First, the most important mechanism understanding in the present invention is to perform an oxidation reaction using propylene as a raw material under the solid catalyst of the core-shell structure, which will be described in more detail. same.

According to the results of the study by the present inventors in Korean Patent Application No. 98-4340, even though the overall chemical composition is the same in the composition of the components constituting the core-shell structured solid catalyst, the components constituting the core and the shell portion And it can be seen that a large difference in the activity according to the composition ratio. That is, when the core portion has the composition of [(100-z)% Fe _f Ni _g Mo _m O _y + z% SiO ₂ ] and the shell portion has the composition [Bi _n A _a O _x ], a rise between the components Due to the synergy effect, the solid catalyst may exhibit maximum activity. In other words, the lattice oxygen of the core part participates in the reaction to generate a partial oxidation reaction, and at this time, the molecular oxygen, which is a reactant in the shell part, is considered to play a role of filling the empty space by participating in the reaction of the lattice oxygen. If such lattice oxygen does not participate in the reaction, the selectivity of acrolein will be greatly reduced by the complete oxidation reaction. In addition, since it is possible to use less expensive raw materials such as bismuth, there is a great effect on cost reduction.

In addition, the present invention has a great feature in the method for producing acrolein in a high yield by the oxidation reaction of propylene, using the above-described core-shell structured solid catalyst, the oxidation reaction to be described in detail for the conditions do.

First, the oxidation reaction temperature at the time of the propylene oxidation reaction of this invention is 300-500 degreeC, Preferably it is 350-400 degreeC. Here, the reason for limiting the reaction temperature to the above range is for optimizing the activity of the catalyst. If the reaction temperature is outside the above range, the conversion of propylene and the selectivity of acrolein are increased due to the increase of unreacted or by-product. Because it causes a big problem. In addition, the oxidation reaction pressure is 1 to 5 atm, and if it is out of the range, there is a problem that the selectivity of acrolein rapidly decreases, which is not preferable. In the oxidation reaction, the volume ratio of the reactants is set to propylene / oxygen / nitrogen = 1/1 to 20/1 to 20. The reason for limiting the range is that the reaction progress and selectivity are largely changed. Finally, the oxidation reaction is carried out with a contact time of 0.5 to 5 seconds because the reaction progress and the selectivity change are greatly affected as described above.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by Examples.

Comparative Example 1

18.66 g of Fe (NO ₃ ) ₃ .9H ₂ O and 39.33 g of Ni (NO ₃ ) ₃ .6H ₂ O were dissolved in 150 mL of 10% HNO ₃ to form Solution A, (NH ₄ ) ₆ Mo ₇ O ₂₄ . 29.19 g of 4H ₂ O was heated and dissolved in 240 ml of water, and Solution B was prepared by adding 93.83 g of 40% silica sol. The solution A and solution B were mixed, adjusted to pH 3 with ammonia water, evaporated in a hot plate, dried in an oven at 140 ° C., calcined at 290 ° C. and 450 ° C., and then ground to 25 to 70 mesh. And again, it treated 3 hours at 575 degreeC. As a result, the catalyst obtained was [50% MoFe _0.28 Ni _0.82 O _y + 50% SiO ₂ ], as shown in Table 1 below. And, under the catalyst thus obtained, the oxidation reaction was carried out under the oxidation reaction conditions shown in Table 2 below. In addition, the conversion of propylene and the selectivity of acrolein were measured, and the results are shown in Table 2 below.

The selectivity of carbon dioxide, carbon monoxide, methane, ethane, ethylene, etc. among the products generated during the oxidation reaction of propylene was measured by a gas chromatograph method equipped with a flame ionization detector and a thermal conductivity detector. In this case, the conversion of propylene was defined as in Equation 1 below, and the selectivity of acrolein was defined as in Equation 2 below.

Comparative Example 2

When making solution A in the process of Comparative Example 1, except that 0.3 ml of Bi (NO ₃ ) _{3 ·} 5H ₂ O solution (0.25 g / ㎖) and uniformly mixed with 10% HNO ₃ compared with the above It carried out similarly to Example 1. As a result, the catalyst obtained was [Bi _0.03 MoFe _0.28 Ni _0.82 O _y + 50% SiO ₂ ], as shown in Table 1 below. Then, under the catalyst thus obtained, oxidation reaction was carried out under the oxidation reaction conditions shown in Table 2 below, and the conversion of propylene and acrolein selectivity were measured in the same manner as in Comparative Example 1, and the results are shown in Table 2 below. It was.

Comparative Example 3

When Solution A was prepared in the process of Comparative Example 1, 10 ml of 0.3 ml of H ₃ PO ₄ solution (0.05 g / ml) and 0.3 ml of Bi (NO ₃ ) _{3 ·} 5H ₂ O solution (0.25 g / ml) were taken. The same process as in Comparative Example 1 was carried out except that the mixture was uniformly mixed with HNO ₃ . As a result, the obtained catalyst was [Bi _0.03 P _0.03 MoFe _0.28 Ni _0.82 O _y + 50% SiO ₂ ], as shown in Table 1 below. Then, under the catalyst thus obtained, oxidation reaction was carried out under the oxidation reaction conditions shown in Table 2 below, and the conversion of propylene and acrolein selectivity were measured in the same manner as in Comparative Example 1, and the results are shown in Table 2 below. It was.

Comparative Example 4

When Solution A was prepared in the course of Comparative Example 1, 0.1 mL of H ₃ PO ₄ solution (0.05 g / mL) and 0.1 mL of Bi (NO ₃ ) _{3 ·} 5H ₂ O solution (0.25 g / mL) were taken, and 10 The same procedure as in Comparative Example 1 was carried out except that the mixture was uniformly mixed with% HNO ₃ . As a result, the obtained catalyst was [Bi _0.01 P _0.01 MoFe _0.28 Ni _0.82 O _y + 50% SiO ₂ ], as shown in Table 1 below. Then, under the catalyst thus obtained, oxidation reaction was carried out under the oxidation reaction conditions shown in Table 2 below, and the conversion of propylene and acrolein selectivity were measured in the same manner as in Comparative Example 1, and the results are shown in Table 2 below. It was.

Comparative Examples 5 to 8 and Example 1

A core part having [50% MoFe _0.28 Ni _0.82 O _y + 50% SiO ₂ ] was prepared in the same manner as in Comparative Example 1. 2.35 g of this was impregnated with P and Bi in the same manner as in Comparative Example 3. As a result, the obtained catalyst was [Bi _0.03 P _0.03 O _x ] [50% MoFe _0.28 Ni _0.82 O _y + 50% SiO ₂ ] as shown in Table 1 below. Then, under the catalyst thus obtained, oxidation reaction was carried out under the oxidation reaction conditions shown in Table 2 below, and the conversion of propylene and acrolein selectivity were measured in the same manner as in Comparative Example 1, and the results are shown in Table 2 below. It was.

Example 2

As described in Table 1, the same method as in Example 1 was performed to prepare a catalyst having [Bi _0.02 Mo _0.02 O _x ] [50% MoFe _0.28 Ni _0.82 O _y + 50% SiO ₂ ]. Then, under the catalyst thus obtained, oxidation reaction was carried out under the oxidation reaction conditions shown in Table 2 below, and the conversion of propylene and acrolein selectivity were measured in the same manner as in Comparative Example 1, and the results are shown in Table 2 below. It was.

Example 3

The same method as in Example 1 was performed to prepare a catalyst having [Bi _0.03 Mo _0.03 O _x ] [50% MoFe _0.28 Ni _0.82 O _y + 50% SiO ₂ ] as shown in Table 1 below. Then, under the catalyst thus obtained, oxidation reaction was carried out under the oxidation reaction conditions shown in Table 2 below, and the conversion of propylene and acrolein selectivity were measured in the same manner as in Comparative Example 1, and the results are shown in Table 2 below. It was.

As described above, the solid catalyst represented by the formula (1) consisting of a core portion and a shell portion of a specific composition showed a higher activity as compared to the case of using a conventional catalyst composed of a core portion and a shell portion of the comparative example. In addition, since it is possible to use less expensive raw materials such as bismuth, it can be seen that it has a great effect on cost reduction. Therefore, the present invention can produce acrolein in a high yield by oxidizing propylene under such a high accuracy catalyst, which is very useful for industrial production of acrolein.

Claims (2)

In the method for producing acrolein by oxidizing propylene, The oxidation reaction is represented by the following Chemical Formula 1 in which the core portion has the composition [(100-z)% Fe _f Ni _g Mo _m O _y + z% SiO ₂ ] and the shell portion has the composition [Bi _n A _a O _x ] Process for producing acrolein characterized in that it is carried out under a solid catalyst of the core-shell structure. Formula 1 [Bi _n A _a O _x ] [(100-z)% Fe _f Ni _g Mo _m O _y + z% SiO ₂ ] In Formula 1 above: A is at least one element selected from boron, phosphorus and molybdenum; When m is 1, n is 0.001-3, a is 0.001-3, f is 0.01-5, g is 0.1-5, z is 0-90, x and y are values determined to match valences in the core and shell portions, respectively. The method of claim 1, wherein the oxidation reaction is a reaction temperature of 300 to 500 ℃, the reaction pressure is 1 to 5 atm, the volume ratio of the reactants is propylene / oxygen / nitrogen = 1/1 to 20/1 to 20, and A process for producing acrolein, characterized in that carried out under the condition that the contact time is 0.5 to 5 seconds.