阅读说明：本技术 一种环氧氯丙烷的制备方法 (Preparation method of epichlorohydrin ) 是由 纪红兵 周贤太 于海洋 于 2019-10-25 设计创作，主要内容包括：本发明公开了一种环氧氯丙烷的制备方法。该方法以氯丙烯为原料,以氧气为氧化剂,加入一定量的有机溶剂和助剂,以金属卟啉化合物为催化剂,控制反应温度为30～180℃,反应压力为0.2～3.0MPa的条件下进行催化反应得到环氧氯丙烷。本发明具有反应条件温和、催化效果好、工艺简单、环氧氯丙烷选择性高等优点。(The invention discloses a preparation method of epichlorohydrin. The method comprises the steps of taking chloropropene as a raw material, taking oxygen as an oxidant, adding a certain amount of organic solvent and auxiliary agent, taking a metalloporphyrin compound as a catalyst, and carrying out catalytic reaction under the conditions that the reaction temperature is controlled to be 30-180 ℃ and the reaction pressure is 0.2-3.0 MPa to obtain the epichlorohydrin. The invention has the advantages of mild reaction conditions, good catalytic effect, simple process, high selectivity of epoxy chloropropane and the like.)

1. A preparation method of epichlorohydrin is characterized in that chloropropene is used as a raw material, air is used as an oxidant, an organic liquid solvent is added, an auxiliary agent is added, a mononuclear metalloporphyrin with a structure in a general formula (I), a mononuclear metalloporphyrin with a structure in a general formula (II) or a mu-oxo-dinuclear metalloporphyrin with a structure in a general formula (III) is used as a catalyst, catalytic reaction is carried out under the conditions that the reaction temperature is controlled to be 30-180 ℃ and the reaction pressure is 0.2-3.0 MPa to obtain epichlorohydrin, the mol ratio of chloropropene to the auxiliary agent is 1: 0.05-10: 1,

m in the formula (I)₁Transition metal atoms Fe, Co, Mn, Cu, Sn, Pt; m in the formula (II)₂Is transition metal atom Fe, Co, Mn, Sn, Pt, Ru, Rh, X₁Is chloro or carbonyl; m in the formula (III)₃Is a transition metal atom Fe or Mn; r₁、R₂、R₃、R₄And R₅Are all selected from hydrogen, halogen, nitro, methyl, hydroxyl, alkoxy or sulfonic group; the auxiliary agent is at least one selected from benzaldehyde, cumene, furfural, isobutyraldehyde, cyclohexene, acetylacetone and isoprene.

2. The preparation method according to claim 1, characterized in that the mol ratio of chloropropene to auxiliary agent is 1: 0.5-1: 5.

3. The method according to claim 1, wherein the organic liquid solvent is at least one selected from acetonitrile, ethanol, butyl acetate, ethyl acetate, tetrahydrofuran, diethyl ether, pyridine, and methanol.

4. The method according to claim 1, wherein the catalytic reaction temperature is 40 to 100 ℃.

5. The method according to claim 1, wherein the pressure of the oxygen is 0.5 to 2.0 MPa.

Technical Field

The invention relates to a preparation method of epichlorohydrin, in particular to a method for preparing epichlorohydrin by biomimetic catalysis of chloropropene epoxidation.

Background

Epichlorohydrin is a volatile, unstable, colorless, oily liquid, miscible with various organic solvents, and forms an azeotrope with various organic liquids. The molecular structure of the epichlorohydrin contains epoxy groups and chlorine, and the epichlorohydrin can be hydrolyzed under the action of alkali to generate glycerol and reacts with bisphenol A to generate epoxy resin, so that the epichlorohydrin can be used for generating chemical products such as glycerol epoxy resin and the like; also can be used for preparing chlorohydrin rubber, surfactant and the like; epoxy resin is the most main downstream product of epoxy chloropropane, and accounts for about 90% of the yield of epoxy chloropropane, so the demand of epoxy chloropropane is greatly influenced by epoxy resin, the market of epoxy resin sale is not optimistic since the explosion of financial crisis in 2008, but the development of the application of epoxy resin in the high-performance field is not stopped, such as epoxy anisotropic conductive adhesive, marine special coating, equipment pipeline coating, traffic composite material, 3D printing material and the like, and the demand of epoxy resin in the market is continuously increased along with the increase of the demand of global economic recovery epoxy resin in recent years.

At present, the main methods for industrially producing epichlorohydrin are a propylene high-temperature chlorination method, an acetate propylene ester method and a glycerol method. The propylene high-temperature chlorination method is developed successfully by Shell company for decades, and is a very mature industrial production process, the process flow mainly comprises the steps of mixing propylene and chlorine gas for high-temperature reaction to generate chloropropene, continuously combining the chloropropene with hypochlorous acid to generate dichloropropanol, and saponifying the dichloropropanol to generate epichlorohydrin, the epichlorohydrin produced by the method accounts for more than 90% of world productivity, but the propylene high-temperature chlorination method has the problems of high energy consumption in the reaction process, serious corrosion of raw material chlorine gas on equipment, large chloride wastewater amount, difficult treatment and the like, and along with the development requirements of China, the environmental requirements are more strict, and the epichlorohydrin production method is urgently required to be updated and replaced.

The vinyl acetate method is a production process developed by the former Soviet Union academy of sciences and Japan Showa and electrician respectively, and mainly comprises four reaction units, namely, propylene reacts with acetic acid to generate vinyl acetate, vinyl acetate hydrolyzes to generate allyl alcohol, allyl alcohol reacts with chlorine to generate dichloropropanol, and dichloropropanol saponifies under the alkaline condition to generate epichlorohydrin.

The preparation of epichlorohydrin by a glycerol method is as early as 1854, crude glycerol is treated by hydrochloric acid through Bertholt, epichlorohydrin is found through alkali hydrolysis, Wang 34093in the past 50 th generation in China, HCl gas generated in monochloroacetic acid production is filled in glycerol, dichloropropanol is generated through reaction, epichlorohydrin is prepared through saponification, but the price of the glycerol is high at that time and is not suitable for preparing epichlorohydrin, further development is not realized, however, the glycerol serving as a byproduct is greatly produced along with the development of a biodiesel technology, and the price of the glycerol is reduced, so that the process for preparing the epichlorohydrin by the glycerol method is developed again; the main process flow of the glycerol method only comprises two steps of chlorohydrination of glycerol and saponification of dichloropropanol, the reaction condition is mild, the use of chlorine is avoided, but the defect that the production of epichlorohydrin is greatly influenced by the price of the glycerol is obvious.

The success of the production of propylene oxide by the co-oxidation method is greatly inspired for scientists, and the research is carried out deeply on the direct epoxidation process method by taking chloropropene as a raw material, wherein hydrogen peroxide is taken as an oxygen source, and chloropropene is taken as a raw material, so that the direct epoxidation effect is the best.

The metalloporphyrin complex is a compound obtained by simulating cytochrome P450 monooxygenase, can effectively activate oxygen, and can realize high-selectivity oxidation of hydrocarbon compounds under mild conditions. Chinese patent CN101070310 discloses metalloporphyrin catalysis C₆-C₁₈The method for preparing the epoxide by the epoxidation of the long-chain terminal alkene uses oxygen or air as an oxygen source and the long-chain terminal alkene as a reactant to obtain a series of experimental effects with high conversion rate and high selectivity, but has no obvious catalytic effect on the oxidation effect of the halogenated olefin.

Therefore, the development of the epichlorohydrin preparation process which takes chloropropene as a raw material and oxygen or air as an oxidant and has the advantages of mild condition, simple process and high selectivity has very important application prospect.

Disclosure of Invention

The invention aims to provide a method for preparing epichlorohydrin by directly catalyzing chloropropene to perform air epoxidation.

In order to realize the purpose, the adopted technical scheme is as follows:

a preparation method of epichlorohydrin takes chloropropene as a raw material, takes air as an oxidant, adds an organic liquid solvent, adds an auxiliary agent, takes mononuclear metalloporphyrin with a structure of a general formula (I), mononuclear metalloporphyrin with a general formula (II) or mu-oxo-dinuclear metalloporphyrin with a structure of a general formula (III) as a catalyst, controls the reaction temperature to be 30-180 ℃, and carries out catalytic reaction under the reaction pressure of 0.2-3.0 MPa to obtain epichlorohydrin, wherein the mol ratio of chloropropene to the auxiliary agent is 1: 0.05-10: 1,

m in the formula (I)₁Transition metal atoms Fe, Co, Mn, Cu, Sn, Pt; m in the formula (II)₂Is transition metal atom Fe, Co, Mn, Sn, Pt, Ru, Rh, X₁Is chloro or carbonyl; m in the formula (III)₃Is a transition metal atom Fe or Mn, R₁、R₂、R₃、R₄And R₅Are all selected from hydrogen, halogen, nitro, methyl, hydroxyl, alkoxy or sulfonic group; the auxiliary agent is at least one selected from benzaldehyde, cumene, furfural, isobutyraldehyde, cyclohexene, acetylacetone and isoprene.

In the method for preparing propylene oxide, the preferred mol ratio of chloropropene to the auxiliary agent is 1: 0.5-1: 5, the preferred reaction temperature is 40-100 ℃, and the preferred pressure is 0.5-2.0 MPa.

In the above method for preparing propylene oxide, the organic liquid solvent is preferably at least one of acetonitrile, ethanol, butyl acetate, ethyl acetate, tetrahydrofuran, diethyl ether, pyridine, and methanol.

The method takes metalloporphyrin as a catalyst, uniformly dissolves the catalyst in a solvent, and adds an auxiliary agent to carry out catalytic reaction on chloropropene and oxygen under the action of the catalyst to prepare the epichlorohydrin. The addition of the auxiliary agent aims to enable the system to easily generate free radicals and enable oxygen to be activated more easily, so that the epoxidation rate of chloropropene can be increased, and the selectivity of epichlorohydrin can be improved.

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

1. the invention adopts the method of directly epoxidizing chloropropene and oxygen to prepare epichlorohydrin, and avoids the defects of large environmental pollution, long process flow and the like caused by a propylene high-temperature chlorination method and an acetic allyl ester method.

2. The epichlorohydrin prepared by the technology of the invention has high selectivity, simple and easy reaction and easy separation of products.

3. The invention uses metalloporphyrin compound with structure similar to biological enzyme as catalyst, the reaction condition is mild, the energy consumption in the production process is reduced, and the safety is improved.

Detailed Description

The invention is further illustrated by the following examples, without limiting the scope of the invention to the examples.