阅读说明：本技术 一种环己酮轻质油综合利用方法 (Comprehensive utilization method of cyclohexanone light oil ) 是由 季峰崎 李忠于 黄伟 金汉强 赵思远 杨忠林 于 2018-06-06 设计创作，主要内容包括：本发明涉及环己酮生产轻质油的综合利用方法,属于精细化工领域。将轻质油除水后进行加氢还原,加氢后的轻质油进行精馏,分离出环己醇、正戊醇和环戊醇,分离后得到的环己醇进入脱氢塔。脱氢后制得环己酮粗品去往环己酮精制系统；正戊醇和环戊醇作为燃料去往环己酮废碱焚烧装置。本发明方法既可以回收轻质油中有经济价值的组分,降低生产成本,提高经济效益,又可以减少环境污染。(The invention relates to a comprehensive utilization method for producing light oil from cyclohexanone, belonging to the field of fine chemical engineering. And (2) removing water from the light oil, then carrying out hydrogenation reduction, rectifying the hydrogenated light oil, separating cyclohexanol, n-pentanol and cyclopentanol, and feeding the separated cyclohexanol into a dehydrogenation tower. Dehydrogenating to obtain cyclohexanone crude product, and feeding the cyclohexanone crude product to a cyclohexanone refining system; the n-amyl alcohol and cyclopentanol are used as fuel to go to a cyclohexanone waste alkali incineration device. The method of the invention can recover the components with economic value in the light oil, reduce the production cost, improve the economic benefit and reduce the environmental pollution.)

1. A comprehensive utilization method of cyclohexanone light oil is characterized in that the light oil is subjected to hydrogenation reduction after water removal, the hydrogenated light oil is rectified to separate cyclohexanol, n-amyl alcohol and cyclopentanol, the cyclohexanol obtained after separation enters a dehydrogenation tower, and a cyclohexanone crude product is prepared after dehydrogenation and goes to a cyclohexanone refining system.

2. The comprehensive utilization method of cyclohexanone light oil as claimed in claim 1, characterized in that the treated cyclohexanone light oil contains 20-40% of cyclohexanone, 30-60% of cyclohexene oxide, 5-10% of n-amyl alcohol and cyclopentanol, 1-5% of water, 1-5% of cyclohexane and 1-5% of the rest substances.

3. The method for comprehensively utilizing cyclohexanone light oil as claimed in claim 1, wherein the cyclohexanone light oil is subjected to a water removal operation before being treated, the operation pressure of a water removal tower is normal pressure, the operation temperature is 110-: 1-10: 1, enabling the wastewater at the top of the tower to enter a wastewater tank and go to a wastewater treatment system, and enabling anhydrous light oil at the bottom of the tower to enter a hydrogenation reactor.

4. The method for comprehensively utilizing cyclohexanone light oil according to claim 3, characterized in that a fixed bed reactor is adopted in the hydrogenation reduction of the anhydrous light oil, and an anhydrous Raney nickel catalyst is adopted as a hydrogenation catalyst.

5. The method for comprehensively utilizing cyclohexanone light oil according to claim 4, characterized in that when an anhydrous Raney nickel catalyst is adopted, the reaction temperature is 80-120 ℃, the retention time is 4-8h, and the hydrogen-oil ratio is 2: 1-6: 1. the reaction pressure is 2-6 MPa.

6. The method for comprehensively utilizing cyclohexanone light oil according to claim 3, characterized in that a fixed bed reactor is adopted during hydrogenation reduction of the anhydrous light oil, and a palladium-carbon catalyst can be adopted as a hydrogenation catalyst.

7. The method for comprehensively utilizing cyclohexanone light oil according to claim 6, characterized in that when a palladium-carbon catalyst is adopted, the reaction temperature is 60-100 ℃, the retention time is 2-4h, and the hydrogen-oil ratio is 2: 1-6: 1. the reaction pressure is 2-6 MPa.

8. The method for comprehensively utilizing cyclohexanone light oil according to claim 3, characterized in that the anhydrous light oil is hydrogenated and then enters a separation tower, the operation temperature is 70-80 ℃, the operation vacuum degree is 95-100kpa, and the reflux ratio is 1-20: 1, separating the materials of n-amyl alcohol and cyclopentanol from the top of the tower, obtaining cyclohexanol from the bottom of the tower, and enabling the materials of n-amyl alcohol and cyclopentanol to go to a cyclohexanone waste alkali incineration device for use as fuel.

9. The method for comprehensively utilizing cyclohexanone light oil as claimed in claim 8, wherein cyclohexanol is separated in a separation tower and then enters a dehydrogenation tower, and the dehydrogenation tower adopts CuO-ZnO/Al₂O₃The catalyst has a reaction temperature of 220 ℃ and 280 ℃ and a reaction space velocity of 0.5-1h^-1The conversion rate is 85-90%, the selectivity is 95-99%, and the cyclohexanone crude product is prepared.

10. the method for comprehensively utilizing cyclohexanone light oil according to claim 9, characterized in that the crude cyclohexanone product obtained after dehydrogenation is fed into a cyclohexanone refining system in a cyclohexanone production system for refining.

Technical Field

The invention relates to a comprehensive utilization method for producing light oil from cyclohexanone, belonging to the field of fine chemical engineering.

Background

The cyclohexane air oxidation method for preparing cyclohexanone is the most widely applied production process in cyclohexanone production, and 2-5% of by-products with low boiling points, commonly called light oil, can be generated in the production process, wherein the by-products are rich in cyclohexane, cyclohexanone and epoxy cyclohexane, and also contain n-amyl alcohol, cyclopentanol and other impurities. The method has practical significance for the research of recycling of the light oil, and can not only recycle the components with economic value in the light oil to reduce the production cost, but also reduce the environmental pollution.

CN1331077A discloses a method for separating cyclohexene oxide from light oil, which is characterized in that the cyclohexene oxide in the light oil is converted into 2-halogenated cyclohexanol with a higher boiling point, then low boiling point substances are separated, the 2-halogenated cyclohexanol is reduced into cyclohexene oxide through cyclization, and the cyclohexene oxide is obtained through rectification and refining.

CN101225077A discloses a novel ring-opening reaction method for a process of recovering cyclohexene oxide from light oil, which comprises the following steps: the method comprises the steps of carrying out ring-opening reaction on light oil containing epoxy cyclohexane components and hydrochloric acid to separate other components of the light oil from high-boiling 2-chlorocyclohexanol, carrying out ring-closing reaction on the separated collected 2-chlorocyclohexanol and alkali, and rectifying to obtain epoxy cyclohexane, wherein the hydrochloric acid is used in a salt water solution or in a gas state, and the hydrolysis is inhibited by adding salt into the hydrochloric acid or hydrochloric acid gas is not taken into water, so that the problems of hydrolysis side reaction and the like in process production are solved.

CN1106784A discloses a method for recovering n-pentanol and cyclohexene oxide from light oil, which is a byproduct of cyclohexanol and cyclohexanone preparation by cyclohexane oxidation, and the patent is characterized in that: adopting water and cyclohexene oxide in light oil to form binary azeotrope, evaporating crude cyclohexene oxide at 88-90.5 ℃, and adding an organic entrainer to refine to obtain the cyclohexene oxide, wherein the purity can reach 95%, and the recovery rate is more than or equal to 70%; n-amyl alcohol is distilled out at 135 ℃ and 137 ℃, the purity is more than or equal to 95 percent, and the recovery rate is more than or equal to 70 percent. The process is simple, but the product purity can not meet the commodity requirement, and the recovery rate is not high.

At present, research on cyclohexanone light oil focuses on purifying and refining components with higher economic values such as the cyclohexanone and the n-amyl alcohol in the light oil and recycling the components. However, the boiling points of the epoxy cyclohexane, the n-amyl alcohol and other components are close to the boiling points of impurity components in the light oil, and a high-purity product is difficult to obtain by a conventional rectification method, so that the commercial index cannot be reached. The technical means of converting the cyclohexene oxide into high boiling point substances by chemical means and then separating the substances has the problems of impurity introduction, complex operation and easy environmental pollution.

Disclosure of Invention

Because the components in the light oil are complex and have relatively close boiling points, the light oil is difficult to refine and purify to obtain a high-purity byproduct, the invention aims to not refine and separate the epoxycyclohexane, the n-amyl alcohol, the cyclopentanol and other components in the light oil, but to carry out hydrogenation conversion on the useful components of the light oil to convert the useful components into high-boiling cyclohexanol, and the separated cyclohexanol can enter a cyclohexanone production system.

The light oil treated by the method is a byproduct generated in cyclohexanone production, wherein the content of cyclohexanone is 20-40%, the content of epoxy cyclohexane is 30-60%, the content of n-amyl alcohol and cyclopentanol is 5-10%, the content of water is 1-10%, the content of cyclohexane is 1-10%, and the content of the rest substances is 1-5% in percentage by mass.

The light oil is first dewatered, because 1, 2-dihydroxycyclohexanol is produced in hydrogenation process if water is contained, and the reduction selectivity is seriously affected, so that anhydrous Raney nickel catalyst or palladium carbon catalyst is also selected as hydrogenation catalyst. The operating pressure of the water removal tower is normal pressure, the operating temperature is 110-120 ℃, and the reflux ratio is 1: 1-10: 1, enabling the tower top wastewater to enter a wastewater tank and go to a wastewater treatment system, wherein the wastewater contains low-boiling-point impurities such as cyclohexane and the like.

And (3) carrying out hydrogenation reduction on the light oil after water removal, wherein a fixed bed reactor is adopted, and a hydrogenation catalyst is an anhydrous Raney nickel catalyst or a palladium carbon catalyst. When using anhydrous Raney nickel catalyst, the reaction temperature is 80-120 ℃, the retention time is 4-8h, and the hydrogen-oil ratio is 2: 1-6: 1. reaction pressure is 2-6Mpa, conversion rate is 96-100%, and selectivity is 92-96%; when a palladium-carbon catalyst is used, the reaction temperature is 60-100 ℃, the retention time is 2-4h, and the hydrogen-oil ratio is 2: 1-6: 1. reaction pressure is 2-6Mpa, conversion rate is 98-100%, and selectivity is 94-98%.

And (3) introducing the hydrogenated light oil into a separation tower, wherein the operation temperature is 70-80 ℃, the operation vacuum degree is 95-100kpa, and the reflux ratio is 1: 1-20: 1, separating n-pentanol and cyclopentanol from the top of the tower, and obtaining cyclohexanol from the bottom of the tower. And (4) feeding the cyclohexanol obtained after separation into a dehydrogenation tower, and preparing a cyclohexanone crude product to a cyclohexanone refining system after dehydrogenation. The dehydrogenation tower adopts CuO-ZnO/Al₂O₃The catalyst has a reaction temperature of 220 ℃ and 280 ℃ and a reaction space velocity of 0.5-1h^-1The conversion rate is 85-90%, the selectivity is 95-99%, and the cyclohexanone crude product is prepared. The n-amyl alcohol cyclopentanol material separated from the top of the tower contains impurities with similar boiling points, and the refining energy consumption is higher, and the n-amyl alcohol cyclopentanol material is used as fuel and sent to a cyclohexanone waste alkali incineration device.

The method of the invention can recover the components with economic value in the light oil, reduce the production cost, improve the economic benefit and reduce the environmental pollution.

Drawings

FIG. 1 is a schematic process flow diagram of a method according to an embodiment of the present invention.

Detailed Description

The technical solution of the present invention is further explained below with reference to the examples and the accompanying drawings.

The process flow of the following example method refers to figure 1.