阅读说明：本技术 一种合成环氧环己烷的方法 (Method for synthesizing cyclohexene oxide ) 是由 唐勇建 徐瑶 潘光飞 王进 曾挺 于 2020-06-16 设计创作，主要内容包括：本发明公开了一种合成环氧环己烷的方法,包括以下步骤：将环己烯、甲醇、30％过氧化氢溶液预热后进入环氧化反应器,在铁碳催化剂的作用下,进行连续反应；将反应产物进行降温分层,得到水层和有机层,水层回收甲醇后甲醇套用,降温分层,废水去三废处理；有机层泵入精馏塔,精馏分离得到未反应的环己烯、甲醇回用,升温至125℃,切换接收罐,继续升温收集中馏分,得到环氧环己烷。本发明合成环氧环己烷的方法在固定床反应器内可实现连续生产,反应条件温和,产品质量稳定,副产物少,易分离。(The invention discloses a method for synthesizing cyclohexene oxide, which comprises the following steps: preheating cyclohexene, methanol and a 30% hydrogen peroxide solution, then feeding the preheated cyclohexene, methanol and the 30% hydrogen peroxide solution into an epoxidation reactor, and carrying out continuous reaction under the action of an iron-carbon catalyst; cooling and layering the reaction product to obtain a water layer and an organic layer, recycling methanol from the water layer, recycling the methanol, cooling and layering, and removing three wastes from the wastewater; pumping the organic layer into a rectifying tower, rectifying and separating to obtain unreacted cyclohexene and methanol for recycling, heating to 125 ℃, switching a receiving tank, continuously heating and collecting middle distillate to obtain the cyclohexene oxide. The method for synthesizing the cyclohexene oxide can realize continuous production in a fixed bed reactor, and has the advantages of mild reaction conditions, stable product quality, less by-products and easy separation.)

1. A method for synthesizing cyclohexene oxide is characterized by comprising the following steps:

step S10, preheating cyclohexene, methanol and a 30% hydrogen peroxide solution, then feeding the preheated cyclohexene, methanol and the 30% hydrogen peroxide solution into an epoxidation reactor, and carrying out continuous reaction under the action of an iron-carbon catalyst and at the reaction temperature of 50-90 ℃ and the pressure of 0.3-0.8 MPa;

step S20, cooling and layering the reaction product to obtain a water layer and an organic layer;

step S30, recycling methanol from the water layer, recycling the methanol, cooling and layering, and treating waste water by three wastes;

and step S40, pumping the organic layer into a rectifying tower, rectifying and separating to obtain unreacted cyclohexene and methanol for recycling, heating to 125 ℃, switching a receiving tank, and continuously heating to collect middle distillate to obtain cyclohexene oxide.

2. The method for synthesizing epoxycyclohexane according to claim 1, wherein in step S10, the epoxidation reactor is a fixed bed reactor.

3. The method for synthesizing cyclohexene oxide according to claim 1, wherein in step S10, the weight ratio of cyclohexene to methanol is 1.5-2.5: 1.

4. The method for synthesizing cyclohexene oxide according to claim 1, wherein in step S10, the preparation method of the iron-carbon catalyst comprises:

step i, grinding activated carbon particles, screening the particles with the particle size of 40-60 meshes, washing off impurities and powder, placing the particles into a 10% nitric acid solution for treatment for 2-4 hours, filtering, washing with water to be neutral, drying and activating to obtain pretreated activated carbon;

step ii, mixing a sodium phosphate solution and a ferric nitrate solution, adding concentrated sulfuric acid, stirring uniformly, then adding a sodium molybdate solution, adding the concentrated sulfuric acid while stirring until the mixed solution is clear, extracting heteropoly acid by using ether, and separating and removing the ether to obtain a solid substance;

and step iii, dissolving the solid matter in water, adding the pretreated activated carbon obtained in the step i, heating and refluxing for 5 hours in a water bath at 60 ℃, filtering and washing to be neutral, and drying to constant weight to obtain the iron-carbon catalyst.

5. The method for synthesizing cyclohexene oxide according to claim 4, wherein in step i, the activated carbon is selected from one or at least two of coconut shell carbon, fiber carbon, coal carbon, wood carbon and shell carbon.

6. The method for synthesizing cyclohexene oxide according to claim 4, wherein the activation temperature in step i is 260-280 ℃ and the activation time is 2.5-4 hours.

7. The method for synthesizing cyclohexene oxide according to claim 4, wherein in the step ii, the molar ratio of the sodium phosphate, the ferric nitrate and the sodium molybdate is 1:1: 9-14.

8. The method for synthesizing cyclohexene oxide according to claim 4, wherein in step iii, the weight ratio of the solid substance to the pretreated activated carbon is 25-32: 100.

9. The method for synthesizing cyclohexene oxide according to claim 1, wherein the collection temperature of the middle distillate in the step S20 is 126-136 ℃.

Technical Field

The invention relates to the technical field of organic matter oxidation, in particular to a method for synthesizing cyclohexene oxide.

Background

The epoxy cyclohexane is a fine chemical raw material with relatively active chemical properties, has a wide application range, can be used for synthesizing a surfactant, a rubber auxiliary agent and the like, and is a main raw material for synthesizing an intermediate of a pesticide acaricide propargite (2- (4-tert-butylphenoxy) cyclohexyl-propyl-2-alkynyl sulfite) and a propargite emulsifiable concentrate.

The synthesis method of the epoxy cyclohexane comprises the following steps: 1. the method is characterized in that the method is recovered from light oil waste liquid in caprolactam production or light oil in cyclohexanone preparation by cyclohexane oxidation, but the yield of the method is limited by the influence of lactam production, and the development of products at the downstream of epoxy cyclohexane is restricted; 2. the cyclohexene epoxidation is used for synthesizing cyclohexene oxide, and includes hypochlorous acid epoxidation, sodium hypochlorite epoxidation, alkyl hydrogen peroxide epoxidation, electrochemical epoxidation, hydrogen peroxide epoxidation and the like. The hydrogen peroxide in the hydrogen peroxide epoxidation method is an oxidant widely applied in recent years, has the characteristics of low price, environmental friendliness and no toxicity or pollution of an oxidation product, and accords with the development trend of green chemistry.

Chinese patent CN101691363A is a method for preparing cyclohexene oxide by catalytic epoxidation of cyclohexene, which uses a synthesized titanium-silicon molecular sieve as a catalyst, uses an alkaline assistant, controls the reaction temperature, stirs the reaction, reacts hydrogen peroxide with cyclohexene in an organic solvent to generate cyclohexene oxide, and then separates and purifies the cyclohexene oxide to prepare the cyclohexene oxide.

Chinese patent CN109535103A discloses a method for preparing oxirane by oxidizing cyclohexene, which uses cyclohexene as raw material and hydrogen peroxide as oxygen source, uses a microchannel mixer to intensively mix cyclohexene, solvent, hydrogen peroxide and catalyst, and then performs epoxidation to generate cyclohexene oxide in a tubular reactor, but the selectivity and yield of cyclohexene oxide prepared by the method are poor.

Disclosure of Invention

The invention aims at the problems and provides a method for synthesizing cyclohexene oxide.

The technical scheme adopted by the invention for solving the problems is as follows: a method for synthesizing epoxycyclohexane, comprising the steps of:

step S10, preheating cyclohexene, methanol and a 30% hydrogen peroxide solution, then feeding the preheated cyclohexene, methanol and the 30% hydrogen peroxide solution into an epoxidation reactor, and carrying out continuous reaction under the action of an iron-carbon catalyst and at the reaction temperature of 50-90 ℃ and the pressure of 0.3-0.8 MPa;

step S20, cooling and layering the reaction product to obtain a water layer and an organic layer;

step S30, recycling methanol from the water layer, recycling the methanol, cooling and layering, and treating waste water by three wastes;

and step S40, pumping the organic layer into a rectifying tower, rectifying and separating to obtain unreacted cyclohexene and methanol for recycling, heating to 125 ℃, switching a receiving tank, and continuously heating to collect middle distillate to obtain cyclohexene oxide.

Further, in step S10, the epoxidation reactor is a fixed bed reactor.

Further, in step S10, the weight ratio of cyclohexene to methanol is 1.5 to 2.5: 1.

Further, in step S10, the method for preparing the iron-carbon catalyst includes:

step i, grinding activated carbon particles, screening the particles with the particle size of 40-60 meshes, washing off impurities and powder, placing the particles into a 10% nitric acid solution for treatment for 2-4 hours, filtering, washing with water to be neutral, drying and activating to obtain pretreated activated carbon;

step ii, mixing a sodium phosphate solution and a ferric nitrate solution, adding concentrated sulfuric acid, stirring uniformly, then adding a sodium molybdate solution, adding the concentrated sulfuric acid while stirring until the mixed solution is clear, extracting heteropoly acid by using ether, and separating and removing the ether to obtain a solid substance;

step iii, dissolving the solid matter in water, adding the pretreated activated carbon obtained in the step i, heating and refluxing for 5 hours in a water bath at 60 ℃, filtering and washing to be neutral, and drying to constant weight to obtain an iron-carbon catalyst; before the solid substance is dissolved in water, the solid substance is purified: dissolving in a small amount of water, concentrating in vacuum drier to crystallize, filtering, and washing to obtainPurified solid substance H₆PMo₁₁FeO₄₀。

Further, in step i, the activated carbon is selected from one or at least two of coconut shell carbon, fiber carbon, coal carbon, wood carbon and fruit shell carbon.

Furthermore, in the step i, the activation temperature is 260-280 ℃ and the activation time is 2.5-4 hours.

Furthermore, in the step ii, the molar ratio of the sodium phosphate to the ferric nitrate to the sodium molybdate is 1:1: 9-14.

Furthermore, in the step iii, the weight ratio of the solid matter to the pretreated activated carbon is 25-32: 100.

Further, in step S20, the collection temperature of the middle distillate is 126-136 ℃.

(1) The method for synthesizing the cyclohexene oxide can realize continuous production in a fixed bed reactor, has mild reaction conditions, stable product quality, less by-products and easy separation;

(2) the catalyst in the method for synthesizing the cyclohexene oxide is a Keggin type heteropolyacid iron-carbon catalyst, the transition metal Fe ions are used for replacing Keggin type phosphomolybdic acid as the catalyst, the reaction temperature required for synthesizing the cyclohexene oxide by using the catalyst is low, the catalyst is easy to control, the product selectivity is strong, the byproducts are few, the catalyst can be repeatedly used, the preparation method of the catalyst is simple, the preparation process is easy to operate, the economic benefit is high, and the method is suitable for large-scale production;

(3) the iron loaded on the activated carbon in the catalyst of the method for synthesizing the cyclohexene oxide can effectively inhibit the passivation of iron-carbon materials and prolong the service life of the catalyst, the specific surface area and the pore volume of the pretreated activated carbon are greatly increased, the provided reaction active sites are increased, and the catalytic effect of the reaction is greatly enhanced.

Detailed Description

The following detailed description of embodiments of the invention, but the invention can be practiced in many different ways, as defined and covered by the claims.