CN105085438B - A kind of preparation method of propylene oxide - Google Patents

Abstract

The invention discloses a kind of preparation methods of propylene oxide.This method is using propylene as raw material, and using oxygen as oxidant, organic solvent and auxiliary agent is added, and using metal porphyrins as catalyst, control is 30 ~ 140 in reaction temperature^oC, reaction pressure carry out catalysis under conditions of being 0.3 ~ 3.0MPa and propylene oxide are obtained by the reaction.The present invention has many advantages, such as reaction condition mild, excellent catalytic effect, propylene oxide high selectivity, simple for process.

Description

A kind of preparation method of propylene oxide

technical field

The invention relates to a method for preparing propylene oxide, in particular to a method for preparing propylene oxide through biomimetic catalyzed epoxidation of propylene.

Background technique

Propylene oxide (PO) is the third largest organic chemical product in propylene derivatives after polypropylene and acrylonitrile. Propylene oxide is widely used. In addition to producing polyether polyols and glycerol, it can also be used to produce propylene glycol, nonionic surfactants, oilfield demulsifiers, pesticide emulsifiers and wetting agents. With the expansion of the use of propylene oxide and the continuous growth of the use of downstream products, the market demand for propylene oxide is increasing year by year.

At present, the main methods for industrially producing propylene oxide are chlorohydrin method, co-oxidation method (also known as indirect oxidation method, or Halcon method) and hydrogen peroxide oxidation method (also known as HPPO method). The chlorohydrin method is gradually eliminated due to the large amount of saline wastewater and organic chlorides produced during the production process, equipment corrosion and serious sewage discharge. The co-oxidation method has a long process, a large investment, and many co-production products, which are seriously restricted by market factors. The disadvantage of the hydrogen peroxide oxidation method is that the cost of hydrogen peroxide is high and the safety is not high. Therefore, the development of a process for the preparation of propylene oxide by direct oxidation of propylene with oxygen or air has important prospects.

In recent years, researchers at home and abroad have been committed to the research of green catalytic process for producing PO with simple process, less by-products and no pollution. Molecular oxygen is cheap, easy to obtain and non-polluting, and is the most ideal oxygen source. Therefore, the direct epoxidation of propylene-oxygen is a research hotspot. However, at present, most of them focus on the gas-solid phase reaction catalyzed by modified Ag-based catalysts. The required reaction conditions are harsh, high temperature and pressure are required, and the selectivity of propylene oxide still needs to be further improved.

Metalloporphyrin complexes are effective mimics of cytochrome P450 monooxygenases, which have a very high activation ability for oxygen and can achieve highly selective oxidation of hydrocarbons under mild conditions. Chinese patent ZL201010239648.6 discloses a method for preparing propylene oxide by metalloporphyrin-catalyzed epoxidation of propylene, which uses acrolein and its derivatives as co-reducing agents, but the acrylic acid series compounds produced are easy to polymerize in the system , making it difficult to control the reaction system, and the catalyst is easily deactivated.

Therefore, the development of a propylene oxide preparation process with propylene as raw material, oxygen as oxidant, mild conditions, simple process and high selectivity will have very important application prospects.

Contents of the invention

The object of the present invention is to provide a method for preparing propylene oxide by liquid-phase oxidation of propylene.

In order to realize the purpose of the present invention, the technical scheme adopted is: take gaseous propylene as raw material, take oxygen as oxidant, add organic liquid solvent, add auxiliary agent isoprene, with the mononuclear metal of general formula (I) structure Porphyrin or the μ-oxygen-binuclear metalloporphyrin of the general formula (II) structure is used as a catalyst or the oxometalloporphyrin of the general formula (III) structure, and the reaction temperature is controlled at 30-150° C., and the reaction pressure is 0.3-3.0 Under the condition of MPa, the catalytic reaction is carried out to obtain propylene oxide, and the molar ratio of propylene to auxiliary agent is 1:0.1～1:5.

M in general formula (I) ₁ is transition metal atom Mg, Al, Cr, Mn, Fe, Co, Ni, Cu or Zn, R is hydrogen or carboxyl or sulfonic acid group; M in general formula (II) ₂ is metal atom Cr, Ni, Cu, Zn, Rh or Sn, X is halogen or hydrogen, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are all selected from hydrogen, halogen, nitro, alkyl, alkoxy Base, hydroxyl, carboxyl, mercapto or sulfonic acid group, ligand X ₁ is chlorine or imidazole or pyridine; M in general formula (III) ₃ is metal atom Mo, Fe, Mn, V, Ti, Ru or Rh, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are all selected from hydrogen, halogen, nitro, alkyl, alkoxy, hydroxyl, carboxyl, mercapto or sulfonic acid; M ₄ in general formula (IV) is a metal atom Al, Co, Zn, Ru or Rh, and R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are all selected from hydrogen, halogen, nitro, alkyl, alkoxy, hydroxyl, carboxyl, mercapto or Sulfonic acid group.

In the above method for preparing propylene oxide, the molar ratio of the propylene to the auxiliary agent is 1:1˜1:3.

In the above method for preparing propylene oxide, the organic liquid solvent is at least one selected from methanol, ethanol, ethyl acetate, acetonitrile, toluene, methylene chloride or N,N-dimethylformamide.

The preferred reaction temperature of the method of the present invention is 60-100° C., the preferred reaction pressure is 1.0-2.0 MPa, and the preferred catalyst concentration is 1-100 ppm.

The invention firstly synthesizes enzyme catalysts such as metal phthalocyanine and metal porphyrin, dissolves the catalyst uniformly in a solvent, adds an auxiliary agent, and makes propylene and oxygen carry out a catalytic reaction under the action of the catalyst to prepare propylene oxide. The added additive isoprene is a bulk chemical raw material in industry, and its purpose is to promote the activation of oxygen in the process of biomimetic catalysis, thereby accelerating the epoxidation rate of propylene and improving the selectivity of propylene oxide.

Compared with the prior art, the present invention has the following beneficial effects:

1. What the present invention adopts is the method for direct epoxidation of propylene and oxygen to prepare propylene oxide, which avoids the disadvantages of using the chlorohydrin method or the co-oxidation method to bring environment and complex products.

2. The selectivity of propylene oxide in the present invention is high, the reaction operation is simple and easy, and the product is easy to separate.

3. The reaction condition of the present invention is mild, the energy consumption of the production process is reduced, and the safety is also improved at the same time.

Detailed ways

The present invention will be further described below in conjunction with Examples and Comparative Examples, but the protection scope of the present invention is not limited to the scope indicated by Examples.

Example 1

Add 0.01 mol of isoprene to 25 mL of acetonitrile solution containing 0.1 mmol of cobalt phthalocyanine (R = H, M ₁ = Co in general formula (I), and fill with 0.8 MPa of propylene and 1.2 MPa of oxygen respectively. , and the stirring reaction was carried out at a temperature of 30°C. According to chromatographic analysis, the conversion rate of propylene was 26%, and the selectivity of propylene oxide was 94%.

Example 2

Add 5.0 mmol isoprene to 25 mL of acetonitrile solution containing 1.0×10 ^-3 mmol tetracarboxy copper phthalocyanine (R=COOH in general formula (I), M ₁ =Cu), and fill with 0.1 MPa propylene respectively and 0.2 MPa of oxygen at a temperature of 50° C. for a stirring reaction. According to chromatographic analysis, the conversion rate of propylene is 38%, and the selectivity of propylene oxide is 95%.

Example 3

In 25mL containing 1.5×10 ^-3 mmol p-nitrotetraphenylruthenium porphyrin chloride (R ₃ =NO ₂ in the general formula (II), R ₁ =R ₂ =R ₄ =R ₅ =H, M ₃ = Ru, X=H, X ₁ =Cl) in acetonitrile solution, add 0.2mol of isoprene, fill with 0.4MPa of propylene and 0.6MPa of oxygen respectively, carry out stirring reaction at a temperature of 60°C, and chromatograph Analysis showed that the conversion of propylene was 56%, and the selectivity of propylene oxide was 96%.

Example 4

Contain 0.8× ^10-3 mmol o-hydroxytetraphenylmanganese porphyrin chloride in 25 mL (R ₁ =OH, R ₂ =R ₃ =R ₄ =R ₅ =H, M ₃ =Mn, X=H, X ₁ =Cl) in ethanol solution, add 0.3mol of isoprene, fill with 0.4MPa of propylene and 2.6MPa of oxygen respectively, carry out stirring reaction at a temperature of 90°C, and analyze by chromatography. The conversion of propylene was 45%, and the selectivity to propylene oxide was 93%.

Example 5

In 25 mL containing 1.8×10 ^-3 mmol 3,4-disulfonic acid tetraphenyliron porphyrin chloride (R ₂ ＝R ₄ ＝SO ₃ H, R ₁ ＝R ₃ ＝R ₅ ＝H, M ₃ ＝Fe, X＝H, X ₁ ＝Cl) in methanol solution, add 6.0mmol of isoprene, fill with 0.6MPa propylene and 0.8MPa air respectively, at the temperature of 60℃ Stirring reaction was carried out, and chromatographic analysis showed that the conversion rate of propylene was 54%, and the selectivity of propylene oxide was 95%.

Example 6

In 25 mL containing 0.5×10 ^-3 mmol o-chlorotetraphenylmanganese porphyrin chloride (R ₁ =Cl, R ₂ =R ₃ =R ₄ =R ₅ =H, M ₃ =Mn, X = H, X ₁ = Cl) in dichloromethane solution, add 0.3 mol of isoprene, respectively filled with 0.5 MPa of propylene and 1.0 MPa of oxygen, at a temperature of 80 ° C under stirring reaction, through the gas phase Chromatographic analysis showed that the conversion rate of propylene was 42%, and the selectivity of propylene oxide was 96%.

Example 7

In 50mL containing 1.5×10 ^-3 mmol m-methyltetraphenyliron porphyrin chloride (R ₂ ＝CH ₃ , R ₁ ＝R ₃ ＝R ₄ ＝R ₅ ＝H, M ₃ ＝ Fe, X=H, X ₁ =Cl) in ethyl acetate solution, add 0.06mol of isoprene, fill with 0.6MPa of propylene and 1.8MPa of oxygen respectively, and carry out stirring reaction at a temperature of 150°C, After chromatographic analysis, the conversion rate of propylene was 59%, and the selectivity of propylene oxide was 90%.

Example 8

In 25mL containing 0.6×10 ^-3 mmol octabromochlorinated o-nitrotetraphenyl manganese porphyrin (R ₁ =NO ₂ , R ₂ =R ₃ =R ₄ =R ₅ =H, M ₃ = Mn, X = Br, X ₁ = Cl) in toluene solution, add 0.5 mol of isoprene, respectively fill with 0.8 MPa of propylene and 1.6 MPa of oxygen, and carry out stirring reaction at a temperature of 80 ° C, After chromatographic analysis, the conversion rate of propylene was 62%, and the selectivity of propylene oxide was 97%.

Example 9

Contain 0.6×10 ^-3 mmol p-bromooxytetraphenylmolybdenum porphyrin in 25mL (R ₁ , R ₂ , R ₄ , R ₅ =H in general formula (III), R ₃ =NO ₂ , M ₃ =Mo ) in the acetonitrile solution, add 0.2mol of isoprene, charge 0.4MPa of propylene and 1.6MPa of oxygen respectively, and carry out stirring reaction at a temperature of 60°C. Through chromatographic analysis, the conversion rate of propylene is 42%. The selectivity to propylene oxide was 94%.

Example 10

Contain 0.6×10 ^-3 mmol m-methyloxytetraphenylvanadium porphyrin in 25mL (R ₁ , R ₂ , R ₃ , R ₄ , R ₅ ＝CH ₃ , M ₃ ＝V in general formula (III) Add 0.6 mol of isoprene to the ethyl acetate solution, fill with 0.9 MPa of propylene and 1.8 MPa of oxygen respectively, and carry out stirring reaction at a temperature of 90 ° C. According to chromatographic analysis, the conversion rate of propylene is 52%. , the selectivity of propylene oxide is 97%.

Example 11

In 25 mL of acetonitrile containing 0.6×10 ^-3 mmol m-carboxytetraphenylruthenium porphyrin (R ₁ , R ₂ , R ₃ , R ₄ , R ₅ =COOH, M ₃ =Ru in general formula (III)) In the solution, add 1.0mol of isoprene, respectively fill 0.5MPa of propylene and 1.5MPa of oxygen, and carry out stirring reaction at a temperature of 60°C. After chromatographic analysis, the conversion rate of propylene is 32%. The selectivity is 97%.

Example 12

In 25 mL of ethanol containing 0.8×10 ^-4 mmol μ-oxygen-binuclear tetraphenylmanganese porphyrin (R ₁ ＝R ₂ ＝R ₃ ＝R ₄ ＝R ₅ ＝H, M ₄ ＝Mn in general formula (IV) In the solution, add 0.1mol of isoprene, respectively fill in 0.4MPa of propylene and 1.2MPa of oxygen, and carry out stirring reaction at a temperature of 60°C. After chromatographic analysis, the conversion rate of propylene is 47%. Propylene oxide The selectivity is 95%.

Example 13

1.5×10 ^-4 mmol μ-oxygen-binuclear o-chlorotetraphenyliron porphyrin in 25 mL (R _{1 =} Cl, R ₂ =R 3 =R ₄ =R ₅ =H, M ₄ = Fe) in N,N-dimethylformamide solution, add 0.4mol of isoprene, fill with 0.8MPa of propylene and 1.2MPa of oxygen respectively, carry out stirring reaction at a temperature of 80°C, and analyze by chromatography , the conversion rate of propylene was 51%, and the selectivity of propylene oxide was 93%.

Claims (6)

1. a preparation method of propylene oxide is characterized in that taking gas propylene as raw material, taking oxygen as oxygenant, adding organic liquid solvent, adding auxiliary agent isoprene, with the mononuclear metal of general formula (I) structure Porphyrin or the μ-oxygen-binuclear metalloporphyrin of the general formula (II) structure is a catalyst or the oxometalloporphyrin of the general formula (III) structure or the general formula (IV) structure, and the reaction temperature is controlled at 30 to 150°C , the reaction pressure is 0.3 ~ 3.0MPa under the condition of catalytic reaction to obtain propylene oxide, the molar ratio of propylene and additives is 1:0.1 ~ 1:5, M in the general formula (I) is _a transition metal atom Fe, Co, Ni or Cu, and R is hydrogen; R ₃ ＝NO ₂ , R ₁ ＝R ₂ ＝R ₄ ＝R ₅ ＝H, M ₂ ＝Ru, X＝H, X ₁ ＝Cl in general formula (II); R ₁ ＝OH in general formula (II) , R ₂ =R ₃ =R ₄ =R ₅ =H, M ₂ =Mn, X=H, X ₁ =Cl; or R ₂ =R ₄ =SO ₃ H, R ₁ =R ₃ =R ₅ =H , M ₂ =Fe, X=H, X ₁ =Cl; or R ₁ =Cl, R ₂ =R ₃ =R ₄ =R ₅ =H, M ₂ =Mn, X=H, X ₁ =Cl; or R ₂ =CH ₃ , R ₁ =R ₃ =R ₄ =R ₅ =H, M ₂ =Fe, X=H, X ₁ =Cl; or R ₁ =NO ₂ , R ₂ =R ₃ =R ₄ = _R5 =H, _M2 =Mn, X=Br, _X1 =Cl; M ₃ in the general formula (III) is a metal atom Mo, V or Ru, and R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are all selected from hydrogen, nitro or carboxyl; R ₁ =R ₂ =R ₃ =R ₄ =R ₅ =H, M ₄ =Mn in general formula (IV); or R ₁ =Cl, R ₂ =R 3 =R ₄ = _{R 5 =} H, M ₄ = Fe. 2. The method according to claim 1, characterized in that the molar ratio of propylene to auxiliary agent is 1:1 to 1:3. 3. The method according to claim 1, wherein said organic liquid solvent is selected from at least one of methanol, ethanol, ethyl acetate, acetonitrile, toluene, methylene chloride or N,N-dimethylformamide kind. 4. The method according to claim 1, characterized in that the temperature of the catalytic reaction is 60-100°C. 5. The method according to claim 1, characterized in that the reaction pressure is 1.0-2.0 MPa. 6. The method according to claim 1, characterized in that the catalyst concentration is 1-100 ppm.