KR20120107353A - Fabrication method of 1,3-butadiene from 2,3-butanediol - Google Patents

Abstract

PURPOSE: A manufacturing method of 1,3-butadiene is provided to obtain 1,3-butadiene with high selectivity through a dehydration of 2,3-butandiol, and to able to manufacture 1,3-butadiene at low temperature with long term stability. CONSTITUTION: A manufacturing method of 1,3-butadiene comprises a step of manufacturing 1,3-butadiene from 2,3-butanediol under the presence of a hydroxyapatite-alumina catalyst. The catalyst contains 5-40 weight% of alumina and 60-95 weight% of hydroxyapatite. The 1,3-butadiene is manufactured through a dehydration of the 2,3-butandiols. The dehydration is conducted under conditions of a reaction temperature of 320-430 °C, a reaction pressure of 1-6 atm, and a liquid hour space velocity of 0.3-1.5 h^(-1).

Description

Method for producing 1,3-butadiene from 2,3-butanediol {Fabrication Method of 1,3-Butadiene from 2,3-Butanediol}

The present invention relates to a method for preparing 1,3-butadiene (2,3-butanediol) from 2,3-butanediol, and in particular from 2,3-butanediol, a bio platform compound It is a method for producing 1,3-butadiene with excellent selectivity and relates to a method for producing 1,3-butadiene stably for a long time.

2,3-butanediol (BDO; 2,3-butanediol) is generally prepared by methods produced by fermentation. In particular, due to the surge in demand for synthetic rubber instead of raw rubber during World War II, it was mass-produced as raw material of butadiene.However, as 2,3-butanediol is produced at a low price by supplying butadiene from petroleum in bulk, some fine chemicals are used. Restricted to, greatly reduced.

As the price of naphtha, a raw material of butadiene due to high oil prices, is increasing, the utilization rate of naphtha cracking facilities is reduced by about 10-15%, and the utilization rate will decrease further due to deterioration in the profitability of naphtha cracking facilities due to the recent expansion of ethylene cracking facilities in the Middle East. As a result, butadiene, 2-butanone, and 2,3-dimethyloxirane are expected to have a big disruption in the supply and demand of butadiene, butadiene from biomass (2,3-butanediol), an petroleum substitute, is used to reduce the dependence on petroleum. R & D for preparing 2-butanone and 2,3-dimethyloxirane is being promoted.

As a method for producing 2,3-butanediol (BDO), fermented strains such as bacteria Klebsiella pneumoniae, Bacillus polymyxa or Enterobacter aerogenes are used, and pentoses, xylose and arabinose, etc. Is synthesized by optimizing the culture conditions (temperature, pH, medium composition, carbon source, etc.), and separating and purifying from the fermentation broth using multistage vacuum distillation, solvent extraction, and micropore Teflon membrane separation. (Syu, M.-J. Appl. Microbiol. Biotechnol (2001) 55: 10-18).

2,3-butanediol (BDO) is classified into dry BDO and wet BDO according to the use. Dry BDO has a moisture content of 5% or less and wet BDO has a water content of 5-80%. In the dehydration reaction, dry BDO and Wet BDO with water content of 20% or less are mainly used.The more water is contained in the dehydration reaction, the more the water is dehydrated, the dehydration product is reversely reacted with the reactant, so that the conversion rate is reduced and the evaporation energy is lost. This is because the energy consumption is large.

Butadiene is an important material as a raw material for synthetic rubber, and it becomes a raw material for butadiene styrene rubber (SBR) butadiene acrylonitrile rubber (NBR) polybutadiene. It is also used as a raw material for chloroprene adiponitryl maleic anhydride.

A method for preparing butadiene by dehydration of butanediol is disclosed in US Pat. No. 2,444,538. As butanediol, 1,3-butanediol was used, and as a catalyst, a mixture of sodium phosphate-calcium phosphate-butyl phosphate mixture catalyst was used, and 80% of 1,3-butanediol aqueous solution was reacted at a reaction temperature of 250 to 300 ° C at atmospheric pressure (LHSV). , Liquid Hour Space Velocity) was supplied as 0.28, the yield of butadiene with a purity of 97% was 77% at the reaction time 20 hours, the yield was reduced to 61% after 42 hours.

A method for preparing butadiene by dehydration of 2,3-butanediol is disclosed in US Pat. No. 2,527,120. As a catalyst, kaolin, silica gel, activated carbon, and the like were used as catalysts, and a butadiene was synthesized by supplying a 50% 1,3-butanediol-acetic anhydride solution at a reaction temperature of 500 to 580 ° C and atmospheric pressure. However, the reaction yield and reaction time were not presented in detail.

As described above, in order to commercially produce butadiene through the dehydration reaction of butanediol, development of a method for producing butadiene with high selectivity while maintaining excellent activity even in a long continuous reaction is required.

The present invention provides a method for producing 1,3-butadiene by dehydration of 2,3-butanediol, and in detail, has a very good selectivity of 1,3-butadiene, enables low-temperature reaction, very high It provides an excellent conversion and yield by maintaining the activity, and excellent stability even in long-term dehydration reaction to provide a production method capable of commercial production.

In addition, the present invention provides a catalyst for producing 1,3-butadiene by the dehydration reaction of 2,3-butanediol and a method for producing the same, and dehydration of 2-3-butanediol occurs at low temperature, and is easy to manufacture. In addition, the present invention provides a catalyst having excellent reaction stability, very high activity and high selectivity, and extended catalyst life, and a method of preparing the same.

Hereinafter, a method for preparing 1,3-butadiene of the present invention, a catalyst used in the method, and a method for preparing the catalyst will be described in detail. Hereinafter, the technical and scientific terms used herein will be understood by those skilled in the art without departing from the scope of the present invention. Descriptions of known functions and configurations that may be unnecessarily blurred are omitted.

Applicant conducted experiments using various catalysts to prepare 1,3-butadiene from 2,3-butanediol, and as a result, hydroxyapatite-alumina catalyst was used. When used, it was confirmed that an effective dehydration reaction is carried out at a low reaction temperature, the activity of the dehydration reaction, the selectivity of 1,3-butadiene and the reaction stability are greatly increased, thereby completing the present invention.

In addition, the Applicant has studied in detail the kind of precursor, precipitate pH, stirring condition, heat treatment temperature, etc. in the synthesis of hydroxyapatite-alumina using a phosphate precursor, a calcium precursor and an alumina precursor. It was confirmed that the synthesized hydroxyapatite-alumina further increased the activity, selectivity, and reaction stability of the dehydration reaction, thereby completing the present invention.

Hereinafter, the method for producing 1,3-butadiene according to the present invention will be described in detail.

The preparation method according to the invention is characterized in that 1,3-butadiene is prepared from 2,3-butanediol in the presence of a hydroxyapatite-alumina catalyst.

The hydroxyapatite-alumina catalyst is characterized by containing 60 to 95% by weight of hydroxyapatite and 5 to 40% by weight of alumina, more specifically, 70 to 90% by weight of hydroxyapatite and 10 to 30% by weight It is characterized by containing alumina. The catalyst includes a powder or porous sintered body shape, and the porous sintered body shape includes a pellet shape.

As described above, the production method according to the present invention is characterized in that the selectivity of 1,3-butadiene is greatly increased by adopting hydroxyapatite-alumina as a catalyst, and lowering the dehydration temperature of 2,3-butanediol. It is characterized by the fact that the catalyst maintains extremely high activity even in the long-term dehydration reaction, so that the long-term continuous reaction is possible, and the conversion rate of 2,3-butanediol is very high even in the long-term reaction, and 1,3-butadiene is manufactured in high yield. There is a characteristic to become.

The method for producing 1,3-butadiene according to the present invention may be a continuous reaction or a batch reaction using a fixed bed reactor. As a reaction method using a fixed reactor, a catalyst pellet (pellet) according to the present invention is charged to a fixed reactor and the reactant 2,3-butanediol is continuously supplied to the reactor to produce a product. At this time, the filling rate of the catalyst in the fixed reactor is preferably 30 to 70% by volume. In the case of a continuous batch reaction, it is preferable to use 1 to 10% by weight of the catalyst.

As the stability of the hydroxyapatite-alumina catalyst is very good, low temperature reaction is possible, and high activity is maintained for a long time, the production method of the present invention is continuously dehydrated 2,3-butanediol to 1,3-butadiene It is preferable that it is a continuous reaction which produces continuously.

As described above, the production method of the present invention is characterized in that 1,3-butadiene is prepared by dehydrating 2,3-butanediol in the presence of a hydroxyapatite-alumina catalyst, and the dehydration reaction is performed at 320 to 430 ° C. The reaction temperature, the reaction pressure of 1 to 6 atm and 2,3-butanediol liquid phase space velocity (LHSV) of 0.3 to 1.5 h ^-1 is characterized.

The reaction temperature, the reaction pressure and the liquid phase space velocity are conditions for producing the 1,3-butadiene with a selectivity of 45 mol% or more. The reaction temperature is higher than 430 ° C, or the reaction pressure is lower than 1 atm, and the supply of the reactant If the rate is less than 0.3 hr ^−1, the activity of the catalyst is excessively increased so that hydrocracking side reactions proceed and the selectivity decreases. And if the reaction temperature is less than 320 ℃, or if the reaction pressure is more than 6atm, the feed rate of 2,3-butanediol exceeds 1.5hr ^-1 , the conversion rate is lowered, the other reaction conditions must be severely increased and the cost in the separation and recovery stage of the product Will increase.

Hereinafter, a catalyst for producing 1,3-butadiene and a method for preparing the same according to the present invention will be described in detail.

The catalyst according to the present invention is characterized in that it is a catalyst for preparing 1,3-butadiene from 2,3-butanediol, and the catalyst is a hydroxyapatite-alumina catalyst. Specifically, the catalyst is characterized in that the catalyst for continuously producing 1,3-butadiene by continuously dehydrating 2,3-butanediol.

The hydroxyapatite-alumina catalyst according to the present invention is characterized by containing 60 to 95% by weight of hydroxyapatite and 5 to 40% by weight of alumina, and more particularly, 70 to 90% by weight of hydroxyapatite and 10 to It is characterized by containing 30% by weight of alumina.

When the hydroxyapatite is less than 60% by weight and the alumina is more than 40% by weight, the content of alumina, which is a highly active ingredient, is high, so that the conversion is high and a stable reaction can be performed at a low temperature. Although the selectivity of 2-butanone, which is a dehydration compound of one-molecule water, is slightly increased due to the small content of, the selectivity of 1,3-butadiene, which is a dehydration compound of two-molecule water, is greatly reduced, so the yield of 1,3-butadiene is greatly reduced. In addition, when the hydroxyapatite is more than 95% by weight and the alumina is less than 5% by weight, the content of alumina, which is a highly active ingredient, is low, so that the integrated selectivity of 1,3-butadiene and 2-butanone is high, but in order to obtain a high yield. The reaction temperature must be increased and there is no effect of improving the selectivity of 1,3-butadiene.

Since the catalyst contains 60 to 95% by weight of hydroxyapatite and 5 to 40% by weight of alumina, the catalyst has a conversion ratio of 95 mol% or more even in 100 hours of continuous dehydration reaction, and yields of 1,3-butadiene of 70 mol% or more ( A catalyst having a 1,3-butadiene yield and 2-butanone yield) and a 1,3-butadiene selectivity of 45 mol% or more.

The method for preparing a catalyst for producing 1,3-butadiene from 2,3-butanediol according to the present invention comprises the steps of: (a) preparing an aqueous solution of phosphate by mixing an alkali salt with an aqueous solution containing phosphoric acid; (b) preparing a calcium phosphate salt by mixing and stirring the aqueous solution of calcium precursor to the aqueous solution of phosphate; (c) mixing and stirring an alumina precursor in the aqueous solution of calcium phosphate to prepare calcium phosphate salt-alumina; And (d) preparing a hydroxyapatite (Ca ₅ (PO ₄ ) ₃ (OH))-alumina catalyst by heat-treating the prepared calcium phosphate salt-alumina at 300 to 700 ° C .; .

The phosphoric acid of step (a) is orthophosphoric acid (H ₃ PO ₄ ), pyrophosphoric acid (H ₄ P ₂ O ₇ ), tripolyphosphoric acid (H ₅ P ₃ O ₁₀ ) and tetrapolyphosphoric acid (H ₆ P ₄ O ₁₃ ) In the at least one selected feature, the alkali salt is preferably caustic soda (sodium hydroxide, NaOH), potassium hydroxide (KOH) and lithium hydroxide (LiOH), of which caustic soda (NaOH) is most preferably used. .

In the step (a), the alkali salt is added so that the pH of the aqueous solution of phosphate is 10.0 to 12.0. Accordingly, the aqueous solution of phosphate is characterized in that the pH is 10.0 to 12.0 so that the phosphate is completely dissolved and stable.

The mixing of the alkali salts is preferably carried out by dropping an aqueous solution containing an alkali salt (alkali salt aqueous solution), and the dropping of the aqueous alkali salt solution is preferably performed over 20 minutes to 2 hours. At this time, the mixing may be performed when the alkali salt solution and the phosphoric acid solution is mixed.

The calcium precursor of step (b) is one or more materials selected from calcium chloride, calcium nitrate, calcium sulfate and calcium acetate, the phosphoric acid concentration of the aqueous solution of phosphate of step (b) is 0.1 to 0.4 normal, the calcium precursor aqueous solution of The calcium concentration is 1.0 to 4.0 normal, and the calcium precursor aqueous solution is characterized in that it is mixed with the aqueous phosphate solution so that the molar ratio of phosphorus: calcium is 1: 0.7 to 1.5.

In the mixing of the step (b), the calcium precursor aqueous solution is characterized in that the phosphate solution is dripping at a rate of 3 to 10 ml / min. By dropping the aqueous solution of calcium precursor at a rate of 3 to 10ml / min, it is possible to prevent the formation of unwanted abnormalities, having a very large specific surface area during the heat treatment of step (d), hydroxy that maintains excellent activity for a long time Apatite (Ca ₅ (PO ₄ ) ₃ (OH)) catalysts are prepared.

The stirring of the step (b) is characterized in that it is carried out at 60 to 90 ℃. When the mixture is stirred at 60 ° C. or less, the calcium phosphate salts are not sufficiently bonded. The uniform dispersion of hydroxyapatite and the formation of particles are low. Therefore, the activity is decreased. When heated at 90 ° C. or more, the hydroxyapatite is sodium phosphate (Tri- Sodium Phosphate, Na ₃ PO ₄ ) and sodium phosphate (CaNa ₂ (P ₂ O ₇ )) to produce by-products of calcium phosphate salts, there is a risk of reduced activity and reduced selectivity.

The alumina precursor used in the step (c) is preferably boehmite (γ-AlO (OH), gamma-alumina (γ-Al ₂ O ₃ ), or a mixture thereof, among which 1,3-butadiene Boehmite is most preferably used in view of its high selectivity.

In the step (c), the catalyst is mixed with the aqueous solution of calcium phosphate salt and the alumina precursor such that the catalyst contains 60 to 95% by weight of hydroxyapatite and 5 to 40% by weight of alumina, preferably 70 to 90% by weight of hydroxyapatite. The calcium phosphate salt aqueous solution and the alumina precursor are mixed so as to contain 10 to 30% by weight of alumina.

The heat treatment of step (d) is characterized in that it is carried out at 300 to 700 ℃ in air, preferably 400 to 600 ℃ heat treatment for 3 to 10 hours. When the heat treatment temperature exceeds 700 ° C., the hydroxyapatite particles are densified and the catalytic activity decreases. When the heat treatment temperature is less than 300 ° C., the hydroxyapatite particles are incompletely generated and the conversion rate is lowered.

The manufacturing method comprises the steps of recovering and drying the calcium phosphate salt-alumina prepared after step (c) and before step (d), step (c2), and milled to a size of 5 to 100㎛; And (c3) molding the pulverized calcium phosphate salt-alumina powder into pellets.

The slurry of calcium phosphate salt is prepared by the step (b), and the recovery of the calcium phosphate salt may be performed by filtration of the slurry, and the washing step of filtering the calcium phosphate salt obtained by filtration with distilled water and then filtering It is preferable to carry out more.

The calcium phosphate salt-alumina cake obtained by filtration in step (c) is preferably dried at 80 to 120 ° C. for 5 to 30 hours, and the dried cake is pulverized into powder of 5 to 100 μm size using a grinder. It is preferable. In this case, it is a matter of course that the calcium phosphate salt-alumina aqueous solution may be spray-dried to powder particles having a size of 5 to 100 μm using a spray dryer.

Then, the pulverized powder is molded into pellets in a tablet machine. In this case, 0.5 to 5% by weight of the graphite (Graphite) used as a lubricant and pore control agent to the powder may be mixed into a pellet. Thereafter, a pellet catalyst is prepared by the heat treatment in step (d).

The pellet catalyst is preferable for the production of 1,3-butadiene in a continuous reaction, and in the case of producing 1,3-butadiene in a batch reaction, the step (c2) is performed without the step (c3). A powder catalyst obtained by heat treatment of the pulverized powder can be used.

The method for preparing 1,3-butadiene according to the present invention has the advantage of producing highly selective 1,3-butadiene by dehydration of 2,3-butanediol, and stably 1,3-butadiene at a low temperature for a long time. There is an advantage to manufacture.

The catalyst for preparing 1,3-butadiene according to the present invention has a high activity even at a low reaction temperature, and has the advantage of being a highly selective dehydration catalyst for 2,3-butanediol, and has excellent reaction stability to maintain high activity even in long-term reactions. It has the advantage of having an extended life.

The production method of the catalyst for preparing 1,3-butadiene according to the present invention has the advantage of being easy to prepare, excellent in reaction stability, very high activity and high selectivity, and a catalyst having an extended life.

1 shows the results of X-ray diffraction analysis for the catalyst prepared in Example 1 of the present invention.

The present invention will be described in detail through the following examples. However, the following examples are merely examples of the present invention, and the claims of the present invention are not limited thereto.

(Example 1)

Hydroxyapatite / alumina (Ca ₅ (PO ₄ ) ₃ (OH) / Al ₂ O ₃ 80/20 wt%) catalyst preparation

67.58 g of 50 wt% tetrapolyphosphoric acid (H ₆ P ₄ O ₁₃ ) aqueous solution was dissolved in deionized water to prepare an aqueous 500 ml phosphoric acid solution. 36.0 g of caustic soda (NaOH) was added to the aqueous solution of phosphoric acid for 30 minutes and stirred to prepare an aqueous solution of sodium phosphate (pH 11.1). 48.52 g of calcium chloride (CaCl ₂ O ₂ H ₂ O) was dissolved in deionized water to prepare a 200 ml aqueous solution of calcium precursor, and an aqueous solution of calcium precursor was added to the aqueous solution of sodium phosphate at a rate of 7 ml / min at room temperature for 30 minutes and at 80 ° C. for 2 hours. Stirring produced a calcium phosphate slurry (pH 5.7). After stirring was complete, the slurry solution was filtered, 600 ml of deionized water was added, dispersed, stirred for 20 minutes, and filtered to obtain a calcium phosphate cake.

The calcium phosphate cake was added to 200 ml of deionized water, and while stirring, 9.75 g of boehmite (γ-AlO (OH), Nippon Catalytic Co., Ltd.) was added, stirred at room temperature for 2 hours, and filtered. The filtered calcium phosphate-alumina cake was dried at 80 ° C. for at least 6 hours. The dried product was ground to a size of 20-40 mesh and calcined in air at 500 ° C. for 6 hours to prepare a catalyst containing 80 wt% of hydroxyapatite and 20 wt% of alumina. The calcined catalyst in air was analyzed by XRD, and as shown in FIG. 1, hydroxyapatite (Ca ₅ (PO ₄ ) ₃ OH) and alumina (Al ₂ O ₃ ) structures were confirmed.

Preparation of 1,3-butadiene

6 ml (4.32 g) of the catalyst prepared in Example 1 was charged into a Pyrex stainless tubular reactor having an internal diameter of 6 mm, and 2,3-butanediol was reacted at a reaction temperature of 360 ° C. and 2 atm pressure of liquid hour space velocity (LHSV). ) It was supplied to 0.50hr ^-1 (flow rate 3ml / hr) and dehydrated. The product was recovered as a liquid sample using an ice-cold collector, and the gas that did not condense into liquid was quantitatively analyzed by gas chromatography (GC) equipped with a DB-WAX column by sampling the gas sample with a gas collection syringe. Was done. As a result of analysis, 1,3-butadiene and 2-butanone were the main products, and in addition, 2,3-dimethyloxirane, acetoin, 1-butene-3-ol and the like were produced. The results in Table 1 below summarize the reaction results in 100 hours of reaction, and are expressed in mol%.

(Example 2)

Hydroxyapatite / alumina (Ca ₅ (PO ₄ ) ₃ (OH) / Al ₂ O ₃ = 80/20 wt%) Preparation of catalyst and Preparation of 1,3-butadiene

Example 1 was carried out in the same manner as in the catalyst preparation, except that 8.29 g of gamma-alumina (Strem) as alumina precursor was synthesized in the same manner as in Example 1, using the prepared catalyst was the same as in Example 1 1,3-butadiene was prepared by the method, and the results at 100 hours of the reaction are summarized in Table 1 below.

(Example 3)

Hydroxyapatite / alumina (Ca ₅ (PO ₄ ) ₃ (OH) / Al ₂ O ₃ ) Preparation of Catalyst and Preparation of 1,3-butadiene

A hydroxyapatite-alumina (Ca ₅ (PO ₄ ) ₃ (OH) / Al ₂ O ₃ ) catalyst was prepared to be 92% by weight of hydroxyapatite and 8% by weight of alumina, using the same method as in Example 1, A hydroxyapatite-alumina (Ca ₅ (PO ₄ ) ₃ (OH) / Al ₂ O ₃ ) catalyst was prepared using 3.39 g of Boehemite (γ-AlO (OH), Cataloide AP5, Japan). , 1,3-butadiene was prepared in the same manner as in Example 1 using the prepared catalyst, the results of the reaction 100 hours are summarized in Table 1 below.

(Example 4)

Hydroxyapatite / alumina (Ca ₅ (PO ₄ ) ₃ (OH) / Al ₂ O ₃ ) Preparation of Catalyst and Preparation of 1,3-butadiene

Prepare a hydroxyapatite-alumina (Ca ₅ (PO ₄ ) ₃ (OH) / Al ₂ O ₃ ) catalyst, but boehmite (γ-AlO (OH) to 65% by weight of hydroxyapatite and 35% by weight of alumina Hydroxyapatite-alumina (Ca ₅ (PO ₄ ) ₃ (OH) / Al ₂ O ₃ ) catalyst was prepared in the same manner as in Example 1, except that 21.00 g of Cataloide AP5) was used. , 1,3-butadiene was prepared in the same manner as in Example 1 using the prepared catalyst, the results of the reaction 100 hours are summarized in Table 1 below.

(Table 1)

(Comparative Example 1)

Hydroxyapatite / alumina (Ca ₅ (PO ₄ ) ₃ (OH) / Al ₂ O ₃ = 80/20 wt%) Preparation of catalyst and Preparation of 1,3-butadiene

The catalyst was synthesized in the same manner as in Example 1, except that 12.68 g of aluminum hydroxide (Al (OH) ₃ , Gibbsite, Samjeon Pure Chemical Co., Ltd.) was used as the alumina precursor. 1,3-butadiene was prepared in the same manner as in Example 1, and the results at 100 hours of the reaction are summarized in Table 2 below. In this case,% in Table 2 means mol%.

 (Comparative Example 2)

Hydroxyapatite (Ca ₅ (PO ₄ ) ₃ (OH)) Preparation of Catalyst and Preparation of 1,3-Butadiene

In Example 1, the catalyst was prepared in the same manner as in the preparation of the catalyst, but without mixing the alumina precursor, the prepared calcium phosphate cake was ground and heat treated, and the catalyst was prepared in the same manner as in Example 1 using the prepared catalyst. 3-butadiene was prepared, and the results at 100 hours of the reaction are summarized in Table 2 below.

(Comparative Example 3)

Alumina (Al ₂ O ₃ ) Preparation of Catalyst and Preparation of 1,3-butadiene

To 200 ml of deionized water, 30 g of boehmite (γ-AlO (OH), Cataloide AP5 from Nippon Catalytic Co., Ltd.) was added thereto, stirred at room temperature for 2 hours, and filtered. The filtered alumina cake was dried at 80 ° C. for at least 6 hours. The dried product was ground to a size of 20-40 mesh and calcined in air at 500 ° C. for 6 hours to prepare an alumina catalyst. 1,3-butadiene was prepared in the same manner as in Example 1 using the prepared catalyst. The results at 100 hours of reaction were summarized in Table 2 below.

(Comparative Example 4)

Hydroxyapatite / alumina (Ca ₅ (PO ₄ ) ₃ (OH) / Al ₂ O ₃ ) Preparation of Catalyst and Preparation of 1,3-butadiene

Prepare a hydroxyapatite-alumina (Ca ₅ (PO ₄ ) ₃ (OH) / Al ₂ O ₃ ) catalyst, but boehmite (γ-AlO (OH) to 97% by weight of hydroxyapatite and 3% by weight of alumina ), Except that 1.21 g of Nippon Catalytic Co., Ltd. Cataloide AP5) was used, the catalyst was synthesized in the same manner as in Example 1, and 1,3-butadiene was prepared in the same manner as in Example 1 using the prepared catalyst. The results at 100 hours of reaction are summarized in Table 2 below.

(Comparative Example 5)

Hydroxyapatite / alumina (Ca ₅ (PO ₄ ) ₃ (OH) / Al ₂ O ₃ ) Preparation of Catalyst and Preparation of 1,3-butadiene

Prepare a hydroxyapatite-alumina (Ca ₅ (PO ₄ ) ₃ (OH) / Al ₂ O ₃ ) catalyst, but boehmite (γ-AlO (OH) to 55% by weight of hydroxyapatite and 45% by weight of alumina ), Except that 31.91 g of Cataloide AP5) was used to synthesize a catalyst in the same manner as in Example 1, and 1,3-butadiene was prepared in the same manner as in Example 1 using the prepared catalyst. The results at 100 hours of reaction are summarized in Table 2 below.

(Table 2)

As it is shown in Table 1 to Table 2, the hydroxyapatite according to the invention - hydroxyapatite as compared to alumina _{(Ca 5 (PO 4) 3} (OH) / Al 2 O 3) catalyst (Ca ₅ (PO _{4) 3} In the case of (OH)) catalysts, the conversion was very low, the selectivity of 1,3-butadiene was also low, and in the case of alumina (Al ₂ O ₃ ) catalysts the conversion was high, but the selectivity of 1,3-butadiene was very low. . In addition, in the hydroxyapatite / alumina (Ca ₅ (PO ₄ ) ₃ (OH) / Al ₂ O ₃ ) catalyst, a catalyst outside the range of 60 to 95% by weight of hydroxyapatite and 5 to 40% by weight of alumina is converted to 1 It can be seen that the selectivity of, 3-butadiene is low.

(Examples 5 to 7)

Preparation of 1,3-butadiene

Using the catalyst of Example 1, 1,3-butadiene was prepared in a similar manner to Example 1 by changing the reaction temperature, reaction pressure, and reactant space velocity in the dehydration reaction of 2,3-butanediol under the conditions of Table 3 below. Reaction The reaction results at 50 hours are summarized in Table 3 below. In this case,% in Table 3 means mol%.

(Table 3)

In the range of the reaction temperature, the reaction pressure and the reactant space velocity, the high conversion rate of butanediol of 98% or more and the selectivity of butadiene and butanone are high, about 88 to 91%, and the selectivity of butadiene is higher than 48%. appear.

(Comparative Examples 6 to 8)

Preparation of 1,3-butadiene

The catalyst of Example 1 was used, but 1,3-butadiene was prepared in a similar manner to Example 1 by changing the reaction temperature, reaction pressure, and reactant space velocity during 2,3-butanediol dehydration under the conditions of Table 4 below. And the reaction results in the reaction 50 hours are summarized in Table 4 below. In this case,% in Table 4 means mol%.

(Table 4)

As can be seen from Table 4, when the reaction is carried out at a reaction temperature outside the reaction temperature range of 320 to 430 ° C, the conversion rate is lowered, butadiene selectivity is lowered, and the reaction pressure is 1 to 6 atm, at a reaction pressure outside the range. When the reaction is carried out, it can be seen that the selectivity of butadiene is lowered.

When the components or reaction conditions of the hydroxyapatite / alumina catalyst are outside the scope of the present invention from the results of the above examples and comparative examples, 1,3-butadiene can be produced in high yield by continuously dehydrating 2,3-butanediol. It can be seen that the 1,3-butadiene can be produced in high yield by continuously dehydrating 2,3-butanediol by the reaction method with the hydroxyapatite / alumina catalyst according to the present invention.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Those skilled in the art will recognize that many modifications and variations are possible in light of the above teachings.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (10)

A process for producing 1,3-butadiene, which produces 1,3-butadiene from 2,3-butanediol in the presence of a hydroxyapatite-alumina catalyst. The method of claim 1,
The catalyst is a method for producing 1,3-butadiene containing 60 to 95% by weight of hydroxyapatite and 5 to 40% by weight of alumina. 3. The method according to claim 1 or 2,
The 1,3-butadiene is prepared by the dehydration reaction of the 2,3-butanediol, the dehydration reaction of the 2,3-butanediol is a reaction temperature of 320 to 430 ℃, reaction pressure of 1 to 6 atm and 0.3 to 1.5 A method for preparing 1,3-butadiene, which is carried out under the condition of 2,3-butanediol liquid space velocity (LHSV) of h ^-1 . The method of claim 3,
The method for producing 1,3-butadiene, wherein the selectivity of the 1,3-butadiene is 45 mol% or more in the dehydration reaction for 100 hours. A catalyst for producing 1,3-butadiene from 2,3-butanediol, the catalyst for producing 1,3-butadiene containing hydroxyapatite-alumina. 6. The method of claim 5,
The catalyst is a catalyst for producing 1,3-butadiene containing 60 to 95% by weight of hydroxyapatite and 5 to 40% by weight of alumina. In the method for producing a catalyst for producing 1,3-butadiene from 2,3-butanediol,
(a) mixing an alkali salt with an aqueous solution containing phosphoric acid to prepare an aqueous phosphate solution;
(b) mixing and stirring an aqueous calcium precursor solution into the aqueous phosphate solution to prepare an aqueous calcium phosphate salt solution;
(c) mixing and stirring an alumina precursor in the aqueous solution of calcium phosphate to prepare calcium phosphate salt-alumina; And
(d) heat treating the prepared calcium phosphate salt-alumina at 300 to 700 ° C. to prepare a hydroxyapatite (Ca ₅ (PO ₄ ) ₃ (OH))-alumina catalyst;
Method for producing a catalyst for producing 1,3-butadiene comprising a. 8. The method of claim 7,
The alumina precursor in step (c) is boehmite (γ-AlO (OH)), gamma-alumina (γ-Al ₂ O ₃ ), or a mixture thereof, a method for producing a catalyst for preparing 1,3-butadiene . 8. The method of claim 7,
The catalyst prepared in step (d) is a method for producing a catalyst for producing 1,3-butadiene, characterized in that it contains 60 to 95% by weight of hydroxyapatite and 5 to 40% by weight of alumina. 8. The method of claim 7,
The catalyst prepared in step (d) comprises 70 to 90% by weight of hydroxyapatite and 10 to 30% by weight of alumina, the method for producing a catalyst for producing 1,3-butadiene.

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