阅读说明：本技术 氯醇化反应系统及其反应方法 (Chlorohydrination reaction system and reaction method thereof ) 是由 罗淑娟 李琰 李东风 刘德全 邵华伟 于 2019-10-15 设计创作，主要内容包括：本发明涉及氯醇化反应设备领域,公开了一种氯醇化反应系统及其反应方法,氯醇化反应系统包括相互并联在循环主管(100)上的多个子反应器,子反应器的输入端通过第一管路(300)与循环主管相连通,输出端通过第一分支(410)与循环主管相连通、通过第二分支(420)与外接皂化系统相连通；第一管路、第一分支和第二分支上分别设有多个控制阀门,控制阀门的开、闭使子反应器在第一连通状态或第二连通状态间交替切换,且在多个子反应器中任意相邻的两个子反应器的连通状态彼此相反。本发明通过对不同的子反应器的连通状态的交替切换使用,在保证反应收率更高的情况下,整个系统可稳定连续生产。(The invention relates to the field of chlorohydrination reaction equipment, and discloses a chlorohydrination reaction system and a reaction method thereof, wherein the chlorohydrination reaction system comprises a plurality of sub-reactors which are mutually connected in parallel on a circulating main pipe (100), the input ends of the sub-reactors are communicated with the circulating main pipe through a first pipeline (300), and the output ends of the sub-reactors are communicated with the circulating main pipe through a first branch (410) and an external saponification system through a second branch (420); the first pipeline, the first branch and the second branch are respectively provided with a plurality of control valves, the opening and closing of the control valves enable the sub-reactors to be alternately switched between a first communication state or a second communication state, and the communication states of any two adjacent sub-reactors in the plurality of sub-reactors are opposite to each other. The invention can ensure that the whole system can stably and continuously produce under the condition of ensuring higher reaction yield by alternately switching the communication states of different sub-reactors.)

1. A chlorohydrination reaction system is characterized by comprising a plurality of sub-reactors which are mutually connected in parallel on a main circulation pipe (100), wherein the input ends of the sub-reactors are communicated with the main circulation pipe (100) through a first pipeline (300), the output ends of the sub-reactors are communicated with the main circulation pipe (100) through a first branch (410) of a second pipeline, and the output ends of the sub-reactors are communicated with an external saponification system through a second branch (420) of the second pipeline; the first pipeline (300), the first branch (410) and the second branch (420) are respectively provided with a plurality of control valves, the opening and closing of the control valves enable the sub-reactors to be alternately switched between a first communication state communicated with the circulation main pipe (100) and a second communication state communicated with the external saponification system, and the communication states of any two adjacent sub-reactors in the plurality of sub-reactors are opposite to each other.

2. The chlorohydrination reaction system according to claim 1, wherein the main circulation pipe (100) is connected to a plurality of reaction raw material inlet lines, respectively, comprising: a water inlet line (610), a chlorine inlet line (620), a propylene or chloropropene inlet line (630) and a lye inlet line (640).

3. The chlorohydrination reaction system according to claim 2, wherein the section of the main circulation pipe (100) provided with the chlorine inlet line (620) and the propylene or chloropropene inlet line (630) is arranged in a horizontal direction.

4. The chlorohydrination reaction system according to claim 2, wherein the section of the main circulation pipe (100) in which the chlorine inlet line (620) and the propylene or chloropropene inlet line (630) are arranged has an angle of 5 ° to 10 ° with the horizontal.

5. The chlorohydrination reaction system of any one of claims 1-4, wherein the number of sub-reactors provided is two.

6. A reaction method of a chlorohydrination reaction system as described in any one of claims 1 to 5, comprising the steps of:

step 100: inputting reaction raw materials including water, chlorine, propylene or chloropropene and alkali liquor into the chlorohydrination reaction system;

step 200: any two adjacent sub-reactors in the plurality of sub-reactors of the chlorohydrination reaction system are respectively a first sub-reactor (210) and a second sub-reactor (220), the first sub-reactor is in a first communication state communicated with the circulation main pipe (100), and the second sub-reactor is in a second communication state communicated with an external saponification system;

step 300: after the chlorohydrination reaction time is met, switching the communication state of the first sub-reactor (210) and the second sub-reactor (220) to enable the first sub-reactor (210) to be in a second communication state communicated with an external saponification system; the second sub-reactor (220) is in a first communication state communicated with the circulation main pipe (100);

step 400: and after the switching time is met, switching from the step 300 back to the step 200, and repeating the switching cycle until the system is stopped.

7. The reaction process of claim 6, wherein the chlorine gas and the propylene or chloropropene are added in the step 100 in a ratio of chlorine gas: propylene or chloropropene is 1: 0.8-1.5.

8. The reaction method as claimed in claim 6, wherein the alkali solution in step 100 comprises: NaOH, Ca (OH)₂、CaCO₃Or Na₂CO₃And (3) solution.

9. The reaction method according to claim 6, characterized in that in the steps 200 and 300, the pH of the solution in which the chlorohydrination reaction is carried out in the first sub-reactor (210) and the second sub-reactor (220) is < 6.

10. The reaction method according to claim 6, wherein the reaction conditions of the chlorohydrination reactions in steps 200 and 300 specifically include: the reaction pressure is as follows: 0.05-2 MPa; the reaction temperature is as follows: 10 ℃ to 40 ℃.

Technical Field

The invention relates to chlorohydrination reaction equipment, in particular to a chlorohydrination reaction system and a reaction method thereof.

Background

The chlorohydrination reaction is a process method with larger specific gravity adopted in the industrial production of propylene oxide and epichlorohydrin, and is a very critical link in the whole industrial production process. The prior chlorohydrination reaction system is generally composed of a plurality of groups of reaction units connected in series, and adopts multi-stage feeding, so that the conversion rate of chlorohydrins is low due to the limited number of the reaction units connected in series, and simultaneously, a large amount of byproducts and waste water are generated.

Disclosure of Invention

The invention aims to solve the problems of low chlorohydrin conversion rate and large amounts of byproducts and waste water in the prior art, and provides a chlorohydrination reaction system and a reaction method thereof.

In order to achieve the above object, the present invention provides a chlorohydrination reaction system, including a plurality of sub-reactors connected in parallel to a main circulation pipe, wherein the input ends of the sub-reactors are connected to the main circulation pipe through a first pipeline, the output ends of the sub-reactors are connected to the main circulation pipe through a first branch of a second pipeline, and the output ends of the sub-reactors are connected to an external saponification system through a second branch of the second pipeline; the first pipeline, the first branch and the second branch are respectively provided with a plurality of control valves, the opening and closing of the control valves enable the sub-reactors to be alternately switched between a first communication state communicated with the circulation main pipe and a second communication state communicated with the external saponification system, and the communication states of any two adjacent sub-reactors in the plurality of sub-reactors are opposite to each other.

Preferably, the circulation main pipe is respectively connected with a plurality of reaction raw material inlet pipelines, and comprises: a water inlet pipeline, a chlorine inlet pipeline, a propylene or chloropropene inlet pipeline and an alkali liquor inlet pipeline.

Preferably, the section of the main circulation pipe provided with the chlorine inlet pipeline and the propylene or chloropropene inlet pipeline is arranged along the horizontal direction.

Preferably, the first section of the main circulation pipe provided with the chlorine inlet pipeline and the propylene or chloropropene inlet pipeline has an included angle of 5-10 degrees with the horizontal direction.

Preferably, the number of the sub-reactors is two.

The second aspect of the present invention provides a reaction method of the chlorohydrination reaction system, which comprises the following steps:

step 100: inputting reaction raw materials including water, chlorine, propylene or chloropropene and alkali liquor into the chlorohydrination reaction system;

step 200: any two adjacent sub-reactors in the plurality of sub-reactors of the chlorohydrination reaction system are respectively a first sub-reactor and a second sub-reactor, the first sub-reactor is in a first communication state communicated with the circulation main pipe, and the second sub-reactor is in a second communication state communicated with an external saponification system;

step 300: after the chlorohydrination reaction time is met, switching the communication state of the first sub-reactor and the second sub-reactor to enable the first sub-reactor to be in a second communication state communicated with an external saponification system; the second sub-reactor is in a first communication state communicated with the circulation main pipe;

step 400: and after the switching time is met, switching from the step 300 back to the step 200, and repeating the switching cycle until the system is stopped.

Preferably, the adding amount ratio of the chlorine gas to the propylene or chloropropene in the step 100 is chlorine gas: propylene or chloropropene is 1: 0.8-1.5.

Preference is given toIn turn, the lye in the step 100 comprises: NaOH, Ca (OH)₂、CaCO₃Or Na₂CO₃And (3) solution.

Preferably, in the steps 200 and 300, the pH of the solution in which the chlorohydrination reactions were carried out in the first and second sub-reactors was < 6.

Preferably, the reaction conditions of the chlorohydrination reaction in the steps 200 and 300 specifically include: the reaction pressure is as follows: 0.05-2 MPa; the reaction temperature is as follows: 10 ℃ to 40 ℃.

By adopting the technical scheme, the communication state of the sub-reactors is switched, so that the whole system can stably and continuously produce under the condition of ensuring higher reaction yield; reasonably controlling the pH value of the solution in the sub-reactors and reducing the generation of byproducts; the device has compact structure, easy realization, small investment and easy control.

Drawings

FIG. 1 is a schematic diagram of the overall structure of a chlorohydrination reaction system in one embodiment of the present invention;

FIG. 2 is a schematic diagram of the overall structure of a chlorohydrination reaction system in another embodiment of the present invention.

Description of the reference numerals

100 main circulation pipe 210, first sub-reactor 220 and second sub-reactor

300 first pipeline 410 first branch 420 second branch

610 water inlet line 620 chlorine inlet line 630 propylene or chloropropene inlet line

640 lye inlet line 8 first pump 7 second pump

11 first valve 12 second valve 13 first top valve

9 third valve 10 fourth valve 14 second top valve

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

In the present invention, the use of directional terms such as "upper, lower, left, right" generally means upper, lower, left, right as viewed with reference to the accompanying drawings, unless otherwise specified; "inner and outer" generally refer to the inner and outer relative to the profile of the components themselves; "distal and proximal" generally refer to distance relative to the contour of the components themselves.

In one embodiment of the present invention, as shown in fig. 1, there is provided a chlorohydrination reaction system, comprising a plurality of sub-reactors connected in parallel to a main circulation pipe 100, wherein the main circulation pipe 100 should have a certain length, and the sub-reactors should have certain sizes according to production scale, and those skilled in the art can select them according to actual needs. In the embodiment shown in fig. 1, there are only two sub-reactors, a first sub-reactor 210 and a second sub-reactor 220. Theoretically, the number of sub-reactors to be installed may be plural if the cost of the reaction system and the installation site are not taken into consideration. The input ends of the first sub-reactor 210 and the second sub-reactor 220 are communicated with the main circulation pipe 100 through a first pipeline 300, the output ends are communicated with the main circulation pipe 100 through a first branch 410 of a second pipeline 400, and are communicated with an external saponification system (not shown in the figure) through a second branch 420 of the second pipeline 400. The first pipeline 300, the first branch 410 and the second branch 420 are respectively provided with a plurality of control valves, the opening and closing of the control valves alternately switches the first sub-reactor 210 and the second sub-reactor 220 between a first communication state communicated with the main circulation pipe 100 and a second communication state communicated with the external saponification system, and the communication states of the first sub-reactor 210 and the second sub-reactor 220 are opposite to each other in the same period. That is, when the first sub-reactor 210 is connected to the main circulation pipe 100, the reaction raw material undergoes a chlorohydrination reaction in the first sub-reactor 210, and is in a first connection state; at this time, the second sub-reactor 220 is connected to the external saponification system, and the solution in the second sub-reactor 220, which has completed the chlorohydrination reaction in the previous first connection state, is output to the external saponification system and is in the second connection state. After the chlorohydrination reaction time is reached, the communication states of the first sub-reactor 210 and the second sub-reactor 220 are exchanged by opening and closing valves arranged at different positions in the reaction system, the first sub-reactor 210 enters a second communication state, the second sub-reactor 220 enters a first communication state, and the steps are repeated in a circulating manner. It should be noted that the valves disposed at various positions in the entire reaction system are conventional, and the structure and operation thereof are not described in detail herein. The communication state of the first sub-reactor 210 and the second sub-reactor 220 is switched by automatic control through a program of a control center arranged in the reaction system or manual control, and the content of this part is not described herein again. In addition, in the overall reaction system, in addition to the above-mentioned main components, there are other auxiliary devices that constitute the overall reaction system, including, but not limited to: connecting pipes, heat exchangers, pumps, tanks, compressors, control systems, etc., as desired, and can be set by one skilled in the art.

As shown in fig. 1, the main circulation pipe 100 is connected to a plurality of reaction raw material inlet lines, respectively, and includes: a water inlet line 610, a chlorine inlet line 620, a propylene or chloropropene inlet line 630 and a lye inlet line 640. Wherein the lye inlet lines 640 are arranged on the main circulation pipe 100 in the embodiment shown in FIG. 1, in practical application, they can be also preferably arranged directly on the first sub-reactor 210 or on the main circulation pipe 100 before the second sub-reactor 220. The main circulation pipe 100 may comprise horizontal or vertical pipes, and in order to facilitate the transportation of various reaction raw materials, in the embodiment shown in fig. 1, the section of the main circulation pipe 100 provided with the chlorine gas inlet line 620 and the propylene or chloropropene inlet line 630 is arranged along the horizontal direction.

In another aspect, the present invention further provides a reaction method of the chlorohydrination reaction system, including the following steps:

step 100: inputting reaction raw materials including water, chlorine, propylene or chloropropene and alkali liquor into the chlorohydrination reaction system;

step 200: any two adjacent sub-reactors in the plurality of sub-reactors of the chlorohydrination reaction system are respectively a first sub-reactor and a second sub-reactor, the first sub-reactor is in a first communication state communicated with the main circulation pipe 100, and the second sub-reactor is in a second communication state communicated with an external saponification system;

step 300: after the chlorohydrination reaction time is met, switching the communication state of the first sub-reactor and the second sub-reactor to enable the first sub-reactor to be in a second communication state communicated with an external saponification system; the second sub-reactor is in a first communication state with the main circulation pipe 100;

step 400: and after the switching time is met, switching from the step 300 back to the step 200, and repeating the switching cycle until the system is stopped.

In order to achieve a better reaction effect, reaction raw materials need to be input into a reaction system according to a certain proportional relationship, and in general, the adding amount ratio of the chlorine gas to the propylene or chloropropene in the step 100 is chlorine gas: propylene or chloropropene is 1: 0.8-1.5. And the lye in the step 100 comprises: NaOH, Ca (OH)₂、CaCO₃Or Na₂CO₃And (3) solution. In general, the alkali solution is added in a non-continuous manner, depending on the pH of the reaction system. In the steps 200 and 300, the pH of the solution subjected to the chlorohydrination reaction in the first sub-reactor 210 and the second sub-reactor 220 is also required, and usually, the pH is required<6, preferably pH<3. As mentioned above, the alkali solution is not continuously added into the first sub-reactor 210 and the second sub-reactor 220, but is related to the pH value of the solution undergoing the chlorohydrination reaction in the first sub-reactor 210 and the second sub-reactor 220, the addition amount of the alkali solution is dependent on the pH value of the solution undergoing the chlorohydrination reaction in the first sub-reactor 210 and the second sub-reactor 220, and the chlorohydrination reaction is maintained at the pH value<6, preferably pH<3 under the condition of pH value. The chlorine, the propylene or the chloropropene and the water are continuously added, and need to be stably and continuously conveyed in the whole chlorohydrination reaction processAnd (6) adding. In step 200 and step 300, the reaction conditions of the chlorohydrination reaction specifically include: the chlorohydrination reaction pressure is as follows: 0.05-2 MPa; the reaction temperature is as follows: 10 ℃ to 40 ℃.

As shown in fig. 2 and fig. 1, the reaction system of the embodiment shown in fig. 2 is substantially the same as that of the embodiment shown in fig. 1, and the only difference between them is that in the embodiment shown in fig. 2, in order to better dissolve various reaction raw materials, the raw materials are slowly raised during the process of being fed into the reaction system, a tubular reactor effect is achieved in a part of the main circulation pipe 100, and the arrangement direction of the main circulation pipe 100 before and after the chlorine gas inlet line 620 and the propylene or chloropropene inlet line 630 is slightly inclined with respect to the horizontal direction. It is preferable to set the angle between the directional phase and the horizontal direction to 5 ° to 10 °, which is the most preferable angle range. In other words, in the section of the main circulation pipe 100 where the chlorine inlet line 620 and the propylene or chloropropene inlet line 630 are provided, the angle between the directional phase and the horizontal direction is 5 ° to 10 °, for example: 8 degrees.

The operation of the chlorohydrination reaction system provided by the present invention is described in detail below with reference to fig. 1 and 2.

Example 1

In the chlorohydrination reaction system provided in this example, the angle between the main circulation pipe 100 between the chlorine inlet line and the propylene inlet line and the horizontal line is 5 °. The reaction raw materials comprise water, chlorine and propylene which are continuously added into a reaction system; the lye which is not continuously added is sodium hydroxide solution, and the pH value of the solution in the first sub-reactor 210 is controlled to be less than 6; the reaction conditions of the chlorohydrination reaction specifically comprise: the reaction pressure is as follows: 0.05-2 MPa; the reaction temperature is as follows: 10 ℃ to 40 ℃, such as: in this example, the reaction pressure was: 0.1 MPa; the reaction temperature is as follows: at 25 ℃.

First, the first sub-reactor 210 is in a first communication state and the chlorohydrination reaction is carried out, wherein the first valve 11 of the first branch 410 of the outlet line of the first pump 8 is opened, the second valve 12 of the second branch is closed, and the first top valve 13 of the first sub-reactor 210 is opened. The second sub-reactor 220 is in a second communication in which the solution goes to the subsequent saponification system, wherein the third valve 9 in the first branch 410 of the outlet line of the second pump 7 is closed, the fourth valve 10 in the second branch 420 is opened and the second top valve 14 of the second sub-reactor 220 is closed. Next, after the continuous reaction and output for the predetermined chlorohydrination reaction time, the first sub-reactor 210 is switched to the second communication state in which the solution goes to the subsequent saponification system, wherein the first valve 11 of the first branch 410 of the outlet line of the first pump 8 is closed, the second valve 12 of the second branch is opened, and the first top valve 13 of the first sub-reactor 210 is closed. The second sub-reactor 220 is switched to the first communication state for the chlorohydrination reaction, wherein the third valve 9 in the first branch 410 of the outlet line of the second pump 7 is opened, the fourth valve 10 in the second branch 420 is closed, and the second top valve 14 of the second sub-reactor 220 is opened. And finally, after a certain time, switching the communication state of the two sub-reactors, performing chlorohydrination reaction and saponification removal on one sub-reactor, and repeatedly circulating the steps until the system is shut down.

Example 2

In the chlorohydrination reaction system provided in this example, the angle between the main circulation pipe 100 between the chlorine inlet line and the propylene inlet line and the horizontal line is 8 °. The reaction raw materials comprise water, chlorine and propylene which are continuously added into a reaction system; the lye which is not continuously added is sodium hydroxide solution, and the pH value of the solution in the first sub-reactor 210 is controlled to be less than 3; the reaction conditions of the chlorohydrination reaction specifically comprise: the reaction pressure is as follows: 0.05-2 MPa; the reaction temperature is as follows: 10 ℃ to 40 ℃, such as: in this example, the reaction pressure was: 0.8 MPa; the reaction temperature is as follows: at 32 ℃.

First, the first sub-reactor 210 is in a first communication state and the chlorohydrination reaction is carried out, wherein the first valve 11 of the first branch 410 of the outlet line of the first pump 8 is opened, the second valve 12 of the second branch is closed, and the first top valve 13 of the first sub-reactor 210 is opened. The second sub-reactor 220 is in a second communication in which the solution goes to the subsequent saponification system, wherein the third valve 9 in the first branch 410 of the outlet line of the second pump 7 is closed, the fourth valve 10 in the second branch 420 is opened and the second top valve 14 of the second sub-reactor 220 is closed. Next, after the continuous reaction and output for the predetermined chlorohydrination reaction time, the first sub-reactor 210 is switched to the second communication state in which the solution goes to the subsequent saponification system, wherein the first valve 11 of the first branch 410 of the outlet line of the first pump 8 is closed, the second valve 12 of the second branch is opened, and the first top valve 13 of the first sub-reactor 210 is closed. The second sub-reactor 220 is switched to the first communication state for the chlorohydrination reaction, wherein the third valve 9 in the first branch 410 of the outlet line of the second pump 7 is opened, the fourth valve 10 in the second branch 420 is closed, and the second top valve 14 of the second sub-reactor 220 is opened. And finally, after a certain time, switching the communication state of the two sub-reactors, performing chlorohydrination reaction and saponification removal on one sub-reactor, and repeatedly circulating the steps until the system is shut down.

From the above, the invention not only has high reaction yield, but also can save more auxiliary equipment such as feeding metering, heat exchange and the like compared with the multi-stage feeding in the reaction equipment in the prior art because only one chlorine inlet pipeline and one propylene or chloropropene inlet pipeline are needed in the whole reaction system, thereby saving the equipment investment. According to the invention, a plurality of sub-reactors are arranged in the reaction system, particularly two sub-reactors in the two embodiments are switched for use, so that the whole system can stably and continuously produce under the condition of ensuring higher reaction yield. By reasonably controlling the pH value of the solution in the sub-reactors, the generation of byproducts is reduced. The invention has compact structure and easy realization, can be suitable for all newly built devices for synthesizing the chlorohydrin by a chlorine-water method, and is also suitable for modification on the basis of the existing devices. In conclusion, the method effectively improves the yield of the chlorohydrin, reduces the generation of byproducts, and has the advantages of high reaction yield, low investment, easy control and high operation flexibility.

The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, a number of simple variants of the technical solution of the invention are possible, for example, the lye inlet lines can be arranged directly on the first sub-reactor. The invention is not described in detail in order to avoid unnecessary repetition. Such simple modifications and combinations should be considered within the scope of the present disclosure as well.