NL2030946B1

NL2030946B1 - Normal-pressure tubular reactor for cumene hydroperoxide and production process thereof

Info

Publication number: NL2030946B1
Application number: NL2030946A
Authority: NL
Inventors: Yu Miao; Chen Song; Chen Xi; Chen Chun
Original assignee: Liaoning Fqzj Co Ltd
Priority date: 2022-02-15
Filing date: 2022-02-15
Publication date: 2023-08-21

Abstract

Disclosed are a normal—pressure tubular reactor for cumene hydroperoxide and a production process thereof. The reactor includes reactors, spiral tube heat exchangers, a condenser and a connecting pipeline, wherein every two or more reactors (ll) are mutually connected by flanges to form at least four reactor units; a feed port and a discharge port are respectively fabricated on tube walls of a left first reactor unit and a right first reactor unit; one end of each connected reactor unit is connected with the condenser through a reactor connecting tube and a condenser connecting tube, and an air distributor installed in a tube wall of the other end is connected, with an intake connecting tube through an intake connecting tube flange; the intake connecting tube is connected with an intake which is connected with an air compressor, and spiral tube heat exchangers are installed in the reactors.

Description

P955/NLpd

NORMAL-PRESSURE TUBULAR REACTOR FOR CUMENE HYDROPEROXIDE AND

PRODUCTION PROCESS THEREOF

TECHNICAL FIELD

The invention belongs to the technical field of oxidation de- vices for organic peroxides and production processes, and in par- ticular, relates to a normal-pressure tubular reactor for generat- ing cumene hydroperoxide by a cumene-air oxidation reaction and a production process thereof.

BACKGROUND ART

Generation of cumene hydroperoxide (CHP) by a cumene-air oxi- dation reaction is the first-step reaction of the cumene method for generating dicumyl peroxide (DCP), and it is also the most im- portant reaction. Existing cumene oxidation reaction is signifi- cantly influenced by pH value. A reaction system with high acidi- ty, namely low pH value, is very adverse to an oxidation reaction.

Since acidic substances may promote CHP decomposition and phenol as a product of acid decomposition further restrains the reaction, so it is necessary to control pH value in a certain range, and pH value is controlled at 3-7 in general industry. Acidic substances in a reaction system are mainly formic acid and benzoic acid gen- erated by an oxidation side reaction. Sometimes, carbon dioxide content in air is increased, there is air pollution, or the feed cumene brings some acidic substances. In cumene oxidation produc- tion, in order to neutralize acidic substances, a certain amount of low-concentration alkali water solution or alkali salt (e.g., sodium carbonate) water solution is intermittently and artificial- ly added in an oxidation tower at intervals or in a continuous manner in an oxidation process. Artificial intermittent addition of alkali liquid has the problems of control hysteresis, large al- kali concentration fluctuation in an oxidation system, poor alkali addition regularity, incapability of accurate control of pH value of an oxidation liquid in an oxidation reaction, etc.; meanwhile, acid catalysts are used for DCP condensation production process, and when the oxidation liquid is neutral or slightly alkaline, the condensation reaction becomes slow, and is even stopped.

At present, there are two kinds of equipment for generating cumene hydroperoxide by a cumene-air oxidation reaction. One is a multi-tower oxidation reactor adopted by U.S. Helcles Company. The other cne is a large-capacity groove type oxidation reactor adopt- ed by U.S. Universal 0il Products Company. The two reactors cannot timely discharge acidic substances generated in an oxidation reac- tion process. Accumulation of acidic substances reduces pH value and restrains the cumene-air oxidation reaction, so the maximum concentration of the reaction product can only reach about 20%.

Second, CHP is unstable and can be thermally decomposed; thermal decomposition is severe at 80°C, becomes more intensive with tem- perature increment, and usually leads to explosion under the ex- istence of acidic substances in a concentrating system. Therefore, the oxidation liquid cannot be distilled and concentrated under normal temperature, and the safety of the two devices should be further improved. Third, the two reactors have severe back-mixing, high by-product yield which is about 10% of a target product, and poor selectivity. Fourth, due to short dwell time of air, oxygen utilization is low.

SUMMARY

The invention aims to provide an oxidation reactor for cumene hydroperoxide , which has simple structure, low cost, high produc- tivity, good safety and normal-pressure usability.

The objective of the invention is achieved by the following technical solution: a normal-pressure tubular reactor for cumene hydroperoxide, comprising reactors, spiral tube heat exchangers, a condenser and a connecting pipeline. The reactors, the spiral tube heat exchangers and the condenser are connected through the con- necting pipeline, wherein two or more reactors are mutually con- nected by flanges to form a reactor unit, and there are at least four reactor units; a feed port is fabricated on a tube wall of a left first reactor unit, and a discharge port is fabricated on a tube wall of a right first reactor unit; one end of each connected reactor unit is connected with the condenser through a reactor connecting tube and a condenser connecting tube, and an air dis- tributor is installed in a tube wall of the other end, which is connected with an intake connecting tube through an intake con- necting tube flange; the intake connecting tube is connected with an intake, the intake is connected with an air compressor, a reac- tion gas outlet is installed at the top of the condenser and spi- ral tube heat exchangers are installed in the reactors.

Further, a reaction material conveying tube is connected be- tween a tube wall of a left second reactor unit and a tube wall of a right second reactor unit, and a flow meter is installed on the intake connecting tube.

Still further, holes are uniformly fabricated on the air dis- tributor.

A production process of the normal-pressure tubular reactor for cumene hydroperoxide comprises: (1). reaction materials are pumped into the reactors by a charge pump through the feed port; (2). air is pressed into the intake and the intake connecting tube by the air compressor, the air is uniformly distributed by the air distributor and then enters the reactors; (3). in the reactors, heat exchange medium is heated by the spiral tube heat exchangers, the temperature is controlled at 70- 90°C, reaction materials and air are thoroughly mixed, and an oxi- dation reaction is carried out under a normal pressure; (4). acid gas generated by the oxidation reaction is dis- charged from the reaction gas outlet after being cooled by the cooler; (5) after multistage reaction, a reaction product is dis- charged from the discharge port.

The present invention has the following beneficial effects: 1. The normal-pressure tubular reactor for cumene hydroperox- ide has simple structure, low cost and convenient use; 2. The equipment can discharge acidic gas generated in an ox- idation process in a real-time manner, so the reaction process is not restrained. Due to high production efficiency of the equip- ment, the concentration of the oxidation reaction product can reach more than 40%, and compared with existing equipment, the concen- tration is improved by 100%; 3. The purity of the alkali cumene hydroperoxide obtained by concentrating and alkali-washing the crude product generated by continuous reaction can reach about 95%, and compared with exist- ing equipment, the purity is improved by about 20%; 4. The heat exchanger and the cooler of the reactor can accu- rately control the reaction temperature of the oxidation reactor, so equipment safety is significantly improved; 5. There is no back-mixing phenomenon in the reactor, so CHP has high purity and few impurities.

BRIEFT DESCRIPTION OF THE DRAWINGS

FIG. 1 is a pictorial view of a normal-pressure tubular reac- tor for cumene hydroperoxide according to the invention.

FIG. 2 is a top view of an air distributor of a normal- pressure tubular reactor for cumene hydroperoxide according to the invention.

In the figure: l-air compressor, 2-flow meter, 3-air distrib- utor, 4-spiral tube heat exchanger, 5-condenser, 6-reactor con- necting tube, 7-intake, 8-feed port, 9-discharge port, 10-reaction material conveying tube, ll-reaction, 12-reaction gas outlet, 13- condenser connecting tube, l4-intake connecting tube, 15-intake connecting tube flange, 16-air distribution hole.

The embodiments of the invention will be described with ref- erence to the accompanying drawings.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiment 1

A normal-pressure tubular reactor for cumene hydroperoxide comprises reactors 11, spiral tube heat exchangers 4, a condenser 5 and a connecting pipeline. The reactors 11, the spiral tube heat exchangers 4 and the condenser 5 are connected through the con- necting pipeline. There are five reactors 11 mutually connected through flanges to form reactor units, and one end of each con- nected reactor unit is connected with a reactor connecting tube 6 through a flange. The other end of the reactor connecting tube 6 is connected with a condenser connecting tube 13 through a flange.

A condenser connecting tube 13 is connected with the condenser 5, and a reaction gas outlet 12 is installed at the top of the con- denser 5 and is used for discharging acidic gas generated by an oxidation reaction. An air distributor 3 is installed in the pipe-

line of the other end of the reactor unit, and air distribution holes 16 are uniformly fabricated on the air distributor 3. A pipeline of the other end of the reactor unit is connected with the intake connecting tube 14 through an intake connecting tube 5 flange 15. The intake connecting tube 14 is connected with an in- take 7, and the intake 7 is connected with an air compressor 1.

The air distributor 3 is a metal plate prepared by steel materi- als. Air holes are uniformly fabricated on the metal plate, and can uniformly distribute the air input by the air compressor 1 in a tubular reactor unit. The spiral heat exchangers 4 are installed in the reactors, and are connected with a heat source. A feed port 8 is fabricated on a tube wall of a left first reactor, and there are four reactor units. A discharge port 9 is fabricated on a tube wall of a right first reactor unit, and a reaction material con- veying tube 10 is connected between a tube wall of a left second reactor unit and a tube wall of a right second reactor unit. A flow meter 2 is installed on the intake connecting tube 14, and is used for measuring the air flow in the intake connecting tube 14.

A production process of the normal-pressure tubular reactor for cumene hydroperoxide comprises the following steps: reaction materials are pumped into the reactors 11 by a charge pump through the feed port 8; air is pressed into the intake 7 and the intake connecting tube 14 by the air compressor 1, the air is uniformly distributed by the air distributor 3 and then enters the reactors 11; in the reactors 11, heat exchange medium is heated by the spi- ral tube heat exchangers 4, the temperature is controlled at 80°C, reaction materials and air are thoroughly mixed, and an oxidation reaction is carried out under a normal pressure; acid gas generat- ed by the oxidation reaction is discharged from the reaction gas outlet after being cooled by the cooler 5; after multistage reac- tion, a reaction product is discharged from the discharge port 9.

Embodiment 2

For a normal-pressure tubular reactor for cumene hydroperox- ide, there are six reactors 11 and eight reactor units. Other parts and the connection mode of the normal-pressure tubular reac- tor for cumene hydroperoxide are the same as embodiment 1.

A production process of the normal-pressure tubular reactor for cumene hydroperoxide is as follows: in the reactors 11, heat exchange medium is heated by the spiral tube heat exchangers 4, the temperature is controlled at 70°C, reaction materials and air are thoroughly mixed, and an oxidation reaction is carried out un- der a normal pressure; other processes are the same as embodiment 1.

Embodiment 3

For a normal-pressure tubular reactor for cumene hydroperox- ide, there are seven reactors 11 and twelve reactor units. Other parts and the connection mode of the normal-pressure tubular reac- tor for cumene hydroperoxide are the same as embodiment 1.

A production process of the normal-pressure tubular reactor for cumene hydroperoxide is as follows: in the reactors 11, heat exchange medium is heated by the spiral tube heat exchangers 4, the temperature is controlled at 90°, reaction materials and air are thoroughly mixed, and an oxidation reaction is carried out un- der a normal pressure; other processes are the same as embodiment 1.

Claims

CONCLUSIONS

1. Tubular reactor for use at normal pressure for cumene hydroperoxide, comprising reactors (11), spiral tube heat exchangers (4), a condenser (5) and a connecting line, the reactors (11), the spiral tube heat exchangers ( 4) and the condenser (5) are interconnected by means of the connecting pipe, wherein two or more reactors (11) are interconnected by flanges to form a reactor unit, and wherein there are at least four reactor units; wherein a supply port (8) is fabricated on a tube wall of a left first reactor unit, and a discharge port (9) is fabricated on a tube wall of a right first reactor unit; wherein one end of each connected reactor unit is connected to the condenser (5) via a reactor connecting tube (6) and a condenser connecting tube (13), and an air distributor (3) is installed in a tube wall of the other end, connected to an inlet connecting tube (14) via a flange (15) of the inlet connecting tube; wherein the inlet connecting tube (14) is connected to an inlet (7), the inlet (7) is connected to an air compressor (1), a reaction gas outlet (12) is installed at the top of the condenser (5) and spiral tube heat exchangers are installed in the reactors (11).

A tube reactor for use at normal pressure for cumene hydroperoxide as specified in claim 1, wherein a reaction material transport tube (10) is connected between a tube wall of a left second reactor unit and a tube wall of a right second reactor unit, and wherein a flow meter (2) is installed on the inlet connecting pipe (14).

A tubular reactor for use at normal pressure for cumene hydroperoxide according to claim 1 or claim 2, wherein holes (16) are uniformly fabricated on the air distributor (3).

4. Production method using the tubular reactor for use at normal pressure of cumene hydroperoxide, comprising the following steps:

{1). reaction materials are pumped into the reactors (11) by a charge pump through the supply port (8);

(2). air is forced into the inlet (7) and the inlet connecting tube (14) by the air compressor (1), whereby the air is evenly distributed through the air distributor (3) and then enters the reactors (11);

(3). in the reactors (11), the heat exchange medium is heated by the spiral tube heat exchangers (4), controlling the temperature at 70 - 90 °C, thoroughly mixing reaction materials and air and carrying out an oxidation reaction under normal pressure;

(4). acid gas generated by the oxidation reaction is discharged through the reaction gas outlet (12) after being cooled by the cooler (5);

(5). after a multi-stage reaction, a reaction product is discharged from the discharge port (9).