阅读说明：本技术 一种1,3-环已二酮的生产工艺 (Production process of 1, 3-cyclohexanedione ) 是由 张晓臣 李萍 张强 牛巍 于 2019-11-22 设计创作，主要内容包括：本发明公开了一种1,3-环己二酮的生产工艺,包括以下步骤：将水、间苯二酚、氢氧化钠、催化剂混合后泵入微管式反应器中,利用氢气压缩机缓冲罐向微管式反应器中通入氢气,反应好的物料进入沉降分离器分离：其中过量的氢气通过沉降分离器上部的氢气收集管重新回到氢气压缩机缓冲罐循环利用,沉降到沉降分离器底部的物料分为催化剂浆料和混合液B,催化剂通过沉降分离器底部阀门重新进入配料釜循环使用,混合液B抽入酸化釜中酸析后得到1,3-环已二酮。本发明提供的生产工艺加快了反应速度,减少了副反应的发生,循环利用氢气和催化剂,将1,3-环己二酮的收率提高至94％以上,同时提高了生产效率和安全性。(The invention discloses a production process of 1, 3-cyclohexanedione, which comprises the following steps: mixing water, resorcinol, sodium hydroxide and a catalyst, pumping the mixture into a micro-tube reactor, introducing hydrogen into the micro-tube reactor by using a hydrogen compressor buffer tank, and separating the reacted materials in a settling separator: the excessive hydrogen returns to the hydrogen compressor buffer tank again through the hydrogen collecting pipe on the upper part of the sedimentation separator for recycling, the material sedimentated to the bottom of the sedimentation separator is divided into catalyst slurry and mixed liquid B, the catalyst enters the batching kettle again through the valve on the bottom of the sedimentation separator for recycling, and the mixed liquid B is pumped into the acidification kettle for acid precipitation to obtain the 1, 3-cyclohexanedione. The production process provided by the invention has the advantages that the reaction speed is accelerated, the occurrence of side reactions is reduced, the hydrogen and the catalyst are recycled, the yield of the 1, 3-cyclohexanedione is improved to more than 94%, and meanwhile, the production efficiency and the safety are improved.)

1. A production process of 1, 3-cyclohexanedione is characterized by comprising the following steps:

(1) mixing water, resorcinol, sodium hydroxide and a catalyst, and stirring until the mixture is fully dissolved to obtain a mixed solution A;

(2) pumping the mixed solution A into a micro-tube reactor through a connecting pipe, and introducing hydrogen into the micro-tube reactor by using a hydrogen compressor buffer tank to ensure that the mixed solution A fully reacts with the hydrogen in the flowing process of the mixed solution A in the micro-tube reactor;

(3) the material flowing out of the micro-tube reactor enters a settling separator, excessive hydrogen returns to a hydrogen compressor buffer tank again through a hydrogen collecting pipe on the upper part of the settling separator for recycling, the material settled to the bottom is divided into mixed liquid B and a catalyst, the catalyst enters a batching kettle again for recycling, and the mixed liquid B is pumped into an acidification kettle;

(4) dropwise adding hydrochloric acid into the mixed solution B, controlling the reaction temperature to be 25-30 ℃ until the pH value is 2-2.5, cooling to 0-5 ℃, and preserving heat for 5-6h for acidification and rearrangement; centrifuging to obtain a white crude product, and drying to obtain the 1, 3-cyclohexanedione.

2. The process for producing 1, 3-cyclohexanedione as claimed in claim 1, wherein: the weight ratio of the sodium hydroxide to the resorcinol is 1: 2.5-3.5.

3. The process for producing 1, 3-cyclohexanedione as claimed in claim 1, wherein: the catalyst is a supported catalyst, and the active component of the catalyst is active nickel.

4. The process for producing 1, 3-cyclohexanedione according to claim 3, wherein: the amount of the active nickel is 6-10 wt% of resorcinol.

5. The process for producing 1, 3-cyclohexanedione as claimed in claim 1, wherein: the reaction temperature in the step (2) is 60-80 ℃.

6. The process for producing 1, 3-cyclohexanedione as claimed in claim 1, wherein: the air pressure in the microtube type reactor in the step (2) is 1.5-3.0 Mpa.

7. The process for producing 1, 3-cyclohexanedione as claimed in claim 1, wherein: the mixed liquid B is pumped into the acidification kettle through a pipeline on the side wall of the sedimentation separator, a mesh filter is arranged at the opening of the pipeline, and the catalyst enters the batching kettle through a valve at the bottom of the sedimentation separator.

8. The process for producing 1, 3-cyclohexanedione as claimed in claim 1, wherein: the specific steps of the step (4) are as follows: stirring the mixed solution B for 30min, cooling to 20 ℃, starting to dropwise add hydrochloric acid, controlling the reaction temperature to be 25-30, separating out white solid when the pH value is about 5, continuously dropwise adding hydrochloric acid until the pH value is 2-2.5, finishing stirring for 30min, cooling to 0-5 ℃, preserving heat for 5h, and carrying out acidification rearrangement; centrifuging to obtain a white crude product.

Technical Field

The invention belongs to the field of chemical industry, and particularly relates to a production process of 1, 3-cyclohexanedione.

Background

The 1, 3-cyclohexanedione is also named as hexadecyloxirane, is mainly used as a medical intermediate for organic synthesis, and is an intermediate of herbicides sulcotrione and mesotrione. The existing synthesis method of 1, 3-cyclohexanedione generally takes resorcinol and hydrogen as raw materials: putting resorcinol and sodium hydroxide solution into a high-pressure reaction kettle, adding a nickel catalyst, and introducing hydrogen at 50 ℃ and 70-100 atmospheric pressure for reaction for 10-12 h. Then cooling, decompressing, filtering out the catalyst, acidifying the filtrate by concentrated hydrochloric acid, cooling to 0 ℃, and filtering out crystals, namely the 1, 3-cyclohexanedione resorcinol. In addition, the reaction kettle needs to be cooled to room temperature to extract products in reaction liquid after the reaction is finished, so that on one hand, the production efficiency is low, and on the other hand, the temperature needs to be raised when the reduction reaction is carried out again, and the energy consumption is large.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a production process of 1, 3-cyclohexanedione, which solves the problems of low production efficiency and poor safety of the existing production process of 1, 3-cyclohexanedione.

The technical scheme provided by the invention is as follows:

a production process of 1, 3-cyclohexanedione comprises the following steps:

(1) mixing water, resorcinol, sodium hydroxide and a catalyst, and stirring until the mixture is fully dissolved to obtain a mixed solution A;

(2) pumping the mixed solution A into a micro-tube reactor through a connecting pipe, and introducing hydrogen into the micro-tube reactor by using a hydrogen compressor buffer tank to ensure that the mixed solution A fully reacts with the hydrogen in the flowing process of the mixed solution A in the micro-tube reactor;

(3) the material flowing out of the micro-tube reactor enters a settling separator, excessive hydrogen returns to a hydrogen compressor buffer tank again through a hydrogen collecting pipe on the upper part of the settling separator for recycling, the material settled to the bottom is divided into mixed liquid B and a catalyst, the catalyst enters a batching kettle again for recycling, and the mixed liquid B is pumped into an acidification kettle;

(4) dropwise adding hydrochloric acid into the mixed solution B, controlling the reaction temperature to be 25-30 ℃ until the pH value is 2-2.5, cooling to 0-5 ℃, and preserving heat for 5-6h for acidification and rearrangement; centrifuging to obtain a white crude product, and drying to obtain the 1, 3-cyclohexanedione.

On the basis of the technical scheme, the weight ratio of the sodium hydroxide to the resorcinol is 1: 2.5-3.5.

On the basis of the technical scheme, the catalyst is a supported catalyst, and the active component of the supported catalyst is active nickel.

On the basis of the technical scheme, the amount of the active nickel is 6-10 wt% of resorcinol.

On the basis of the technical scheme, the reaction temperature of the step (2) is 60-80 ℃.

On the basis of the technical scheme, the air pressure in the microtube type reactor in the step (2) is 1.5-3.0 MPa.

On the basis of the technical scheme, the mixed liquid B is pumped into the acidification kettle through a pipeline on the side wall of the sedimentation separator, a mesh filter is arranged at the opening of the pipeline, and the catalyst enters the batching kettle through a valve at the bottom of the sedimentation separator.

On the basis of the technical scheme, the specific steps of the step (4) are as follows: stirring the mixed solution B for 30min, cooling to 20 ℃, starting to dropwise add hydrochloric acid, controlling the reaction temperature to be 25-30, separating out white solid when the pH value is about 5, continuously dropwise adding hydrochloric acid until the pH value is 2-2.5, finishing stirring for 30min, cooling to 0-5 ℃, preserving heat for 5h, and carrying out acidification rearrangement; centrifuging to obtain a white crude product.

The reaction principle of the invention is that hydroquinone is hydrogenated under a catalyst, and then hydrochloric acid is used for rearrangement, acidification and crystallization to generate 1, 3-cyclohexanedione, and the chemical reaction principle is as follows:

the invention has the following advantages and beneficial effects:

the invention utilizes the microtube reactor (a plurality of pipelines inside are connected in parallel) to carry out hydrogenation reaction, and because the whole reactor is a closed device, redundant hydrogen is recycled in the reactor, the discharge amount of the hydrogen is reduced, and the pollution caused by the discharge of hydrogen chloride gas carried by the hydrogen discharge to the environment is also reduced; in addition, the efficiency and the service life of the catalyst are improved, the emission of the waste catalyst is reduced, the generation of impurities is reduced, the yield of the product is improved, and the yield reaches more than 94%.

Detailed Description

The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. The reagents and raw materials used are commercially available unless otherwise specified. The experimental methods without specifying specific conditions in the following examples were selected according to the conventional methods and conditions, or according to the commercial instructions.

The hydrochloric acids used in the following examples are hydrochloric acids having a concentration of 36% by weight.