阅读说明：本技术 一种环氧乙烷法制备乙二醇的反应系统及方法 (Reaction system and method for preparing ethylene glycol by ethylene oxide method ) 是由 张志炳 周政 李磊 张锋 孟为民 王宝荣 杨高东 罗华勋 田洪舟 杨国强 曹宇 于 2020-12-17 设计创作，主要内容包括：本发明提供了一种环氧乙烷法制备乙二醇的反应系统及方法,所述反应系统包括：反应器,环氧乙烷进料管道；反应器侧壁设置有NaHCO-3水溶液进料管道,反应器内设置有微界面机组,微界面机组由多个微界面发生器排列形成；环氧乙烷进料管道穿过反应器侧壁进入到微界面机组内部以实现在反应之前环氧乙烷预先在微界面机组内部破碎成微米级别的微气泡；反应器反应后的反应产物进入脱轻塔脱除轻组分,再进入精馏塔精馏处理后得到乙二醇。本发明通过在反应器内部设置微界面机组,使得环氧乙烷在与NaHCO-3水溶液进行反应之前被破碎为微气泡,提高了环氧乙烷与NaHCO-3水溶液之间相界传质面积。(The invention provides a reaction system and a method for preparing ethylene glycol by an ethylene oxide method, wherein the reaction system comprises: a reactor, an ethylene oxide feed line; the side wall of the reactor is provided with NaHCO 3 The reactor is internally provided with a micro-interface unit which is formed by arranging a plurality of micro-interface generators; ethylene oxide feed lines through the reactor side walls into the interior of the micro-interface unit to effect pre-staging of ethylene oxide at the micro-interface prior to reactionBreaking the inside of the machine set into micro bubbles at a micron level; and the reaction product after the reaction of the reactor enters a light component removal tower to remove light components, and then enters a rectifying tower to be rectified to obtain the ethylene glycol. The invention enables the ethylene oxide and NaHCO to react by arranging the micro-interface unit in the reactor 3 The water solution is broken into micro bubbles before reaction, so that the ethylene oxide and NaHCO are improved 3 And the mass transfer area of the phase boundary between the aqueous solutions.)

1. A reaction system for preparing ethylene glycol by an ethylene oxide method is characterized by comprising: a reactor, an ethylene oxide feed line;

the side wall of the reactor is provided with NaHCO₃The reactor comprises a water solution feeding pipeline, wherein a micro-interface unit is arranged in the reactor and is formed by sequentially arranging a plurality of micro-interface generators from top to bottom; the ethylene oxide feeding pipeline penetrates through the side wall of the reactor and enters the inside of the micro interface unit so as to realize that the ethylene oxide is broken into micro bubbles at the micron level in the inside of the micro interface unit in advance before reaction;

and (3) the reaction product reacted from the reactor enters a light component removal tower to remove light components, and then enters a rectifying tower to be rectified to obtain the ethylene glycol.

2. The reaction system of claim 1, wherein the micro interface unit comprises 3 micro interface generators, which are arranged in a staggered manner from top to bottom, the micro interface generators are connected in parallel, a group of liquid reciprocal channels is arranged between adjacent micro interface generators, and the liquid reciprocal channels realize the circulation of gas and liquid in the micro interface generators.

3. The reaction system of claim 1, wherein the micro interface unit comprises 4 micro interface generators, each 2 micro interface generator is divided into two groups, and the two groups are arranged in sequence from top to bottom, 2 micro interface generators in each group are connected in series, the two groups are connected in parallel, a group of liquid reciprocal channels is arranged between the adjacent micro interface generators, and the liquid reciprocal channels realize the circulation of gas and liquid in the micro interface generators.

4. The reaction system of claim 1, wherein the micro interface unit comprises 4 micro interface generators arranged in sequence from top to bottom, the micro interface generators are connected in parallel, a set of liquid reciprocal channels is arranged between adjacent micro interface generators, and the liquid reciprocal channels realize the circulation of gas and liquid in the micro interface generators.

5. The reaction system of claim 1, wherein said NaHCO is₃The aqueous solution feeding pipeline is connected with NaHCO₃Aqueous solution storage tank to be realized as NaHCO into reactor₃The aqueous solution provides a source of raw materials; the ethylene oxide feeding pipeline is connected with an ethylene oxide external channel so as to provide an ethylene oxide gas source for the ethylene oxide to enter the micro-interface unit.

6. The reaction system of any one of claims 1 to 4, wherein the top of the light component removal column is provided with a light component outlet for discharging light components, and the bottom of the light component removal column is provided with a heavy component outlet which is communicated with the side wall of the rectification column for further rectifying the ethylene glycol.

7. The reaction system of any one of claims 1 to 4, wherein the bottom of the rectification column is provided with a raw material recycling outlet, and the NaHCO is used for recycling raw material₃And returning the aqueous solution to the reactor from the raw material recycling outlet to realize recycling of the raw material.

8. The reaction system according to any one of claims 1 to 4, wherein the top of the rectifying tower is provided with an overhead condenser, and a part of the substance condensed from the overhead condenser is returned to the rectifying tower, and the other part of the substance goes to the glycol storage tank.

9. The reaction method of the reaction system for manufacturing ethylene glycol using the ethylene oxide process according to any one of claims 1 to 8, comprising the steps of:

ethylene oxide and NaHCO₃And (3) carrying out reaction after the aqueous solution mixed micro-interface is dispersed and crushed, and then carrying out light component removal and rectification to obtain ethylene glycol for collection.

10. The reaction method of the reaction system according to claim 9, wherein the temperature of the reaction is 78 to 95 ℃ and the pressure of the reaction is 0.8 to 2.0 MPa.

Technical Field

The invention relates to the field of ethylene glycol preparation, and particularly relates to a reaction system and a reaction method for preparing ethylene glycol by an ethylene oxide method.

Background

Ethylene Glycol (EG) is the simplest and most important aliphatic diol, a colorless, odorless, sweet liquid, and can be mixed with water in any ratio. Ethylene glycol has a wide industrial use, and can be used for producing polyethylene terephthalate (a raw material for synthetic polyester fibers and polyester plastics), and for producing other polyester resins, unsaturated polyester resins, nonionic surfactants, ethanolamine, explosives, and the like; the high-purity ethylene glycol can be used for preparing antifreeze and antifreeze of cooling systems in the automobile industry, the aviation industry and the instrument industry, and producing solvents, lubricants, softeners, plasticizers and the like; ethylene glycol is also used in hydraulic brakes, tobacco humectants, fur treating agents, inkpads, and inks. The total demand and consumption of EG in China are huge, and EG has good development prospect in China.

Ethylene glycol production by ethylene oxide process for the development of downstream productsForming a good industrial chain, and is a very good prospect for chemical enterprises at present. Using epoxy ethane as raw material in weak base NaHCO₃Hydrolysis reaction is carried out in the water solution to directly synthesize glycol, and pure glycol is prepared by separation; the ethylene glycol is prepared by the ethylene oxide method, and the reaction temperature must be properly increased for accelerating the reaction speed due to larger reaction activation energy, and the reaction is carried out at 80-100 ℃. However, after the reaction temperature is increased, the corresponding reaction pressure is also increased in order to keep the reaction system in a liquid phase; during the reaction, ethylene oxide and NaHCO₃The aqueous solution cannot be mixed sufficiently, so that the reaction needs to be carried out under high ethylene oxide pressure (more than 2.0MPa), and the production capacity of the reactor is limited (liquid hourly space velocity < 1.0 h)^-1)。

Therefore, there is a need for improved routes to ethylene glycol production.

In view of the above, the present invention is particularly proposed.

Disclosure of Invention

The first purpose of the invention is to provide a reaction system for preparing ethylene glycol by an ethylene oxide method, which arranges a micro-interface unit in a reactor so that ethylene oxide and NaHCO are mixed₃The aqueous solution is broken into micro bubbles before reaction, and the ethylene oxide and NaHCO are improved₃The mass transfer area of the phase boundary between the aqueous solutions is reduced, thereby solving the problem of the prior art that the ethylene oxide and NaHCO are used₃The aqueous solution cannot be sufficiently mixed in the reactor, resulting in problems of high reaction pressure, large hydrogen-ester ratio, and low liquid hourly space velocity.

The second purpose of the invention is to provide a reaction method for preparing ethylene glycol by adopting the reaction system, the ethylene glycol obtained by the reaction has high purity and wide application, the application range of the ethylene glycol is improved, and the method is worthy of wide popularization and application.

In order to achieve the above purpose of the present invention, the following technical solutions are adopted:

the invention provides a reaction system for preparing ethylene glycol by an ethylene oxide method, which comprises the following steps: a reactor, an ethylene oxide feed line;

the side wall of the reactor is provided with NaHCO₃The reactor comprises a water solution feeding pipeline, wherein a micro-interface unit is arranged in the reactor and is formed by sequentially arranging a plurality of micro-interface generators from top to bottom; the ethylene oxide feeding pipeline penetrates through the side wall of the reactor and enters the inside of the micro interface unit, so that ethylene oxide is broken into micro bubbles in a micron level in the micro interface unit in advance before reaction, and the mass transfer effect is improved.

And (3) the reaction product reacted from the reactor enters a light component removal tower to remove light components, and then enters a rectifying tower to be rectified to obtain the ethylene glycol.

Furthermore, the micro-interface unit comprises 3 micro-interface generators which are arranged from top to bottom in a staggered manner, the micro-interface generators are connected in parallel, a group of liquid reciprocal channels are arranged between every two adjacent micro-interface generators, and the liquid reciprocal channels realize the circulation of gas and liquid in the micro-interface generators;

preferably, the micro interface unit is arranged below the inside of the reactor, and is arranged in a mode of sequentially staggering 3 micro interface generators from top to bottom, the micro interface unit is not only arranged in the height direction inside the reactor in a vertically sequential staggered arrangement mode, but also can be uniformly arranged in the radial direction inside the reactor, and the micro interface generators are also arranged in the radial direction inside the reactor, so that the acting volume of the micro interface unit inside the reactor is larger, the acting range is more uniform, the micro interface unit in the prior art is prevented from being sequentially overlapped from top to bottom, and only the limitation at the center of the reactor is limited. NaHCO 2₃From aqueous solution NaHCO₃The aqueous solution is stored in a tank through NaHCO₃The water solution feed pipeline enters the lower part inside the reactor and is taken as a medium to be in close contact with the entering ethylene oxide after entering, so that the ethylene oxide can be fully dispersed and crushed in the micro-interface unit, and the gas phase is fully dispersed and crushed inside the micro-interface generator on the premise that the liquid phase is taken as the medium.

In the invention, a liquid reciprocal channel is also arranged between every two adjacent micro-interface generators;

preferably, the liquid reciprocal channels are arranged in two groups and are arranged in bilateral symmetry, and the crushing degree of the gas phase can be improved through the mutual circulation of liquid among all the micro-interface generators; the power required by the broken gas phase is provided by the microporous structure in the micro-interface generator, and the liquid reciprocal channel also provides power correspondingly in an auxiliary way;

preferably, the liquid phase flow directions of the two groups of liquid reciprocal channels are opposite, so that convection is generated among all the micro-interface generators, and the crushing effect is improved;

a micro-interface generator in the reactor breaks ethylene oxide into micro-bubbles with micron scale, and the micro-bubbles are released into the reactor to increase the ethylene oxide and NaHCO in the reaction process₃The mass transfer area of the phase boundary between the aqueous solutions enables the ethylene oxide to be in a micro-bubble state with NaHCO₃The aqueous solution is brought into full contact and the reaction is carried out.

Furthermore, the micro-interface unit comprises 4 micro-interface generators, wherein each 2 micro-interface generator is divided into two groups, the two groups are sequentially arranged from top to bottom, 2 micro-interface generators in each group are connected in series, the two groups are connected in parallel, a group of liquid reciprocal channels are arranged between the adjacent micro-interface generators, and the liquid reciprocal channels realize the circulation of gas and liquid in the micro-interface generators;

preferably, the micro-interface unit sets up the inside below at the reactor, establish ties according to every 2 micro-interface generators and be a set of, totally two sets of, two sets of mode of arranging that from top to bottom set up in parallel for the micro-interface unit not only arranges the certain altitude range inside the reactor, can also arrange the radial scope inside the reactor, make the radial region inside the reactor also have the micro-interface generator, thereby make the micro-interface unit more even at the inside scope of action of reactor, the micro-interface unit of having avoided prior art overlaps from top to bottom in proper order and places, only concentrate on the limitation at the center of reactor.

Furthermore, the micro-interface unit comprises 4 micro-interface generators which are sequentially arranged from top to bottom, the micro-interface generators are connected in parallel, a group of liquid reciprocal channels are arranged between every two adjacent micro-interface generators, and the liquid reciprocal channels realize the circulation of gas and liquid in the micro-interface generators;

preferably, the micro interface unit is arranged below the inside of the reactor, and the arrangement mode of 4 micro interface generators is sequentially arranged from top to bottom, so that the height range of the micro interface unit arranged inside the reactor is further enlarged, that is, a primary micro interface system is formed in each micro interface generator, so that the gas phase is sufficiently dispersed and crushed inside the micro interface generator on the premise that the liquid phase is used as a medium, the bottommost micro interface generator is separated from a gas phase feed inlet and is used as a dispersed and crushed primary micro interface system, and then the upper 3 micro interface generators form a secondary micro interface system, a tertiary micro interface system and a quartic micro interface system, thereby achieving the effect of enhancing the reaction.

Further, said NaHCO₃The aqueous solution feeding pipeline is connected with NaHCO₃Aqueous solution storage tank to be realized as NaHCO into reactor₃The aqueous solution provides a source of raw materials; the ethylene oxide feeding pipeline is connected with an ethylene oxide external channel so as to provide an ethylene oxide gas source for the ethylene oxide to enter the micro-interface unit.

Further, a light component outlet is formed in the top of the light component removal tower and used for discharging light components, a heavy component outlet is formed in the bottom of the light component removal tower and communicated with the side wall of the rectifying tower and used for further rectifying the ethylene glycol;

and conveying the reaction product after the reaction in the reactor to the inside of a light component removal tower, distilling out light components such as methanol, acetaldehyde and the like from the top of the tower, and conveying the obtained heavy components to a subsequent rectifying tower.

Further, a raw material circulating outlet is arranged at the bottom of the rectifying tower, and NaHCO is used₃Returning the aqueous solution from the raw material recycling outlet to the reactor to realize recycling of the raw material;

further, the top of the rectifying tower is provided with an overhead condenser, a part of substances condensed from the overhead condenser is returned to the rectifying tower, and the other part of substances goes to a glycol storage tank;

the rectifying tower is used for rectifying heavy components in the light component removal tower, and NaHCO remained at the bottom of the rectifying tower₃The aqueous solution is circulated to the interior of the reactor and is reused for NaHCO in the reactor₃And (3) reacting the aqueous solution, namely returning part of the substance passing through the overhead condenser at the top of the rectifying tower to the rectifying tower, and conveying part of distilled glycol to a glycol storage tank.

The invention also provides a reaction method for preparing ethylene glycol by an ethylene oxide method, which comprises the following steps:

ethylene oxide and NaHCO₃And (3) carrying out reaction after the aqueous solution mixed micro-interface is dispersed and crushed, and then carrying out light component removal and rectification to obtain ethylene glycol for collection.

Further, the pressure of the reaction is 0.8-2.0 MPa;

the process conditions for preparing the ethylene glycol by hydrolyzing the ethylene oxide are as follows: ethylene oxide and NaHCO₃The molar ratio of (A) to (B) is: 1:1, the reaction temperature is about 78-95 ℃; the reaction time is 2-3 h.

Because the industrial grade ethylene oxide contains more impurities, the yield is low, and in order to improve the yield of the ethylene glycol, a proper catalyst can be selected during hydrolysis and a proper polymerization inhibitor can be selected during separation to prevent the polyethylene glycol from generating by self polymerization.

Specifically, the preparation method comprises arranging NaHCO inside the reactor₃A micro-interface generator connected with the feeding pipeline of the aqueous solution, so that the ethylene oxide and NaHCO are mixed₃Before the aqueous solution reacts, the micro-interface generator breaks the ethylene oxide into micro-bubbles with the diameter of more than or equal to 1 mu m and less than 1mm, so that the ethylene oxide and NaHCO react in the micro-bubbles state₃Aqueous solution contact to increase the reaction time of ethylene oxide and NaHCO₃The mass transfer area of the phase boundary between the aqueous solutions is increased, and the reaction is carried out after the aqueous solutions are fully mixed, thereby solving the problem that the prior art has ethylene oxide and NaHCO₃The aqueous solution cannot be sufficiently mixed in the reactor, resulting in problems of high reaction pressure and low liquid hourly space velocity.

The ethylene glycol product obtained by the reaction method has good quality and high yield. And the preparation method has low reaction temperature, greatly reduced pressure and high liquid hourly space velocity, which is equivalent to improving the productivity.

It will be appreciated by those skilled in the art that the micro-interface generator used in the present invention is described in the prior patents of the present inventor, such as the patents of application nos. CN201610641119.6, 201610641251.7, CN201710766435.0, CN106187660, CN105903425A, CN109437390A, CN205833127U and CN 207581700U. The detailed structure and operation principle of the micro bubble generator (i.e. micro interface generator) is described in detail in the prior patent CN201610641119.6, which describes that "the micro bubble generator comprises a body and a secondary crushing member, wherein the body is provided with a cavity, the body is provided with an inlet communicated with the cavity, the opposite first end and second end of the cavity are both open, and the cross-sectional area of the cavity decreases from the middle of the cavity to the first end and second end of the cavity; the secondary crushing member is disposed at least one of the first end and the second end of the cavity, a portion of the secondary crushing member is disposed within the cavity, and an annular passage is formed between the secondary crushing member and the through holes open at both ends of the cavity. The micron bubble generator also comprises an air inlet pipe and a liquid inlet pipe. "the specific working principle of the structure disclosed in the application document is as follows: liquid enters the micro-bubble generator tangentially through the liquid inlet pipe, and gas is rotated at a super high speed and cut to break gas bubbles into micro-bubbles at a micron level, so that the mass transfer area between a liquid phase and a gas phase is increased, and the micro-bubble generator in the patent belongs to a pneumatic micro-interface generator. The micro-bubble generator is used for secondarily breaking the bubbles in the cavity by arranging a secondary breaking piece at the first end and/or the second end of the cavity so as to generate more micro-bubbles with smaller diameter; in other words, the secondary crushing member can crush further the bubbles that have been cut and crushed near the axis on the tapered surface of the secondary crushing member, producing more and smaller bubbles.

In addition, the first patent 201610641251.7 describes that the primary bubble breaker has a circulation liquid inlet, a circulation gas inlet and a gas-liquid mixture outlet, and the secondary bubble breaker communicates the feed inlet with the gas-liquid mixture outlet, which indicates that the bubble breakers all need to be mixed with gas and liquid, and in addition, as can be seen from the following drawings, the primary bubble breaker mainly uses the circulation liquid as power, so that the primary bubble breaker belongs to a hydraulic micro-interface generator, and the secondary bubble breaker simultaneously introduces the gas-liquid mixture into an elliptical rotating ball for rotation, thereby realizing bubble breaking in the rotating process, so that the secondary bubble breaker actually belongs to a gas-liquid linkage micro-interface generator. In fact, the micro-interface generator is a specific form of the micro-interface generator, whether it is a hydraulic micro-interface generator or a gas-liquid linkage micro-interface generator, however, the micro-interface generator adopted in the present invention is not limited to the above forms, and the specific structure of the bubble breaker described in the prior patent is only one of the forms that the micro-interface generator of the present invention can adopt.

Furthermore, the prior patent 201710766435.0 states that the principle of the bubble breaker is that high-speed jet flows are used to achieve mutual collision of gases, and also states that the bubble breaker can be used in a micro-interface strengthening reactor to verify the correlation between the bubble breaker and the micro-interface generator; moreover, in the prior patent CN106187660, there is a related description on the specific structure of the bubble breaker, see paragraphs [0031] to [0041] in the specification, and the accompanying drawings, which illustrate the specific working principle of the bubble breaker S-2 in detail, the top of the bubble breaker is a liquid phase inlet, and the side of the bubble breaker is a gas phase inlet, and the liquid phase coming from the top provides the entrainment power, so as to achieve the effect of breaking into ultra-fine bubbles, and in the accompanying drawings, the bubble breaker is also seen to be of a tapered structure, and the diameter of the upper part is larger than that of the lower part, and also for better providing the entrainment power for the liquid phase.

Since the micro-interface generator was just developed in the early stage of the prior patent application, the micro-interface generator was named as a micro-bubble generator (CN201610641119.6), a bubble breaker (201710766435.0) and the like in the early stage, and is named as a micro-interface generator in the later stage along with the continuous technical improvement, and the micro-interface generator in the present invention is equivalent to the micro-bubble generator, the bubble breaker and the like in the prior art, and has different names.

In summary, the micro-interface generator of the present invention belongs to the prior art, although some bubble breakers belong to the type of pneumatic bubble breakers, some bubble breakers belong to the type of hydraulic bubble breakers, and some bubble breakers belong to the type of gas-liquid linkage bubble breakers, the difference between the types is mainly selected according to the different specific working conditions, and in addition, the connection between the micro-interface generator and the reactor and other equipment, including the connection structure and the connection position, is determined according to the structure of the micro-interface generator, which is not limited.

Compared with the prior art, the invention has the beneficial effects that:

(1) the reaction system for preparing the ethylene glycol by the ethylene oxide method of the invention arranges the micro-interface unit in the reactor, so that the ethylene oxide and NaHCO are reacted₃The water solution is broken into micro bubbles before reaction, so that the ethylene oxide and NaHCO are improved₃The mass transfer area of the phase boundary between the aqueous solutions is reduced, thereby solving the problem of the prior art that the ethylene oxide and NaHCO are used₃The water solution can not be fully mixed in the reactor, so that the problems of high reaction pressure and low liquid hourly space velocity are caused;

(2) the reaction method is simple and convenient to operate, the ethylene glycol obtained by the reaction has high purity and wide application, the application range of the ethylene glycol is improved, and the method is worthy of wide popularization and application.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

FIG. 1 is a schematic structural view of a reaction system provided in example 1 of the present invention;

FIG. 2 is a schematic structural view of a reaction system provided in example 2 of the present invention;

fig. 3 is a schematic structural diagram of a reaction system provided in example 3 of the present invention.

Description of the drawings:

11-NaHCO₃an aqueous solution storage tank; 12-ethylene oxide external channel;

13-a reactor; 131-a micro-interface generator;

132-liquid reciprocal channel; 14-a light component removal tower;

141-light fraction outlet; 142-a heavy ends outlet;

15-a rectification column; 151-overhead condenser;

152-a raw material recycle outlet; 16-a glycol storage tank;

17-a first delivery pump; 18-second delivery pump.

Detailed Description

The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and the detailed description, but those skilled in the art will understand that the following described embodiments are some, not all, of the embodiments of the present invention, and are only used for illustrating the present invention, and should not be construed as limiting the scope of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In order to more clearly illustrate the technical solution of the present invention, the following description is made in the form of specific embodiments.

Example 1

Referring to fig. 1, a reaction system for preparing ethylene glycol by an ethylene oxide process according to an embodiment of the present invention mainly includes a reactor 13 and an ethylene oxide feeding pipeline, wherein a sidewall of the reactor 13 is further provided with NaHCO₃A water solution feeding pipeline, wherein a micro-interface unit is arranged in the reactor 13, the micro-interface unit is formed by sequentially arranging a plurality of micro-interface generators 131 in a staggered manner from top to bottom, preferably 3 micro-interface generators 131 are arranged, the micro-interface generators 131 are connected in parallel, two groups of liquid reciprocal channels 132 are arranged between every two adjacent micro-interface generators 131, and the liquid reciprocal channels 132 realize the circulation of gas and liquid in the micro-interface generators 131; an ethylene oxide feed line passes through the side wall of the reactor 13 into the interior of the micro-interface unit to achieve pre-breaking of ethylene oxide into micro-bubbles on the micron scale inside the micro-interface unit prior to reaction.

The ethylene oxide feed pipe is connected with an ethylene oxide external channel 12 to provide a raw material source for the ethylene oxide to enter the micro-interface unit, and NaHCO is used₃The aqueous solution feeding pipeline is connected with NaHCO₃Aqueous solution storage tank 11 to achieve the presence of NaHCO into reactor 13₃The aqueous solution provides the source of the starting material, 50kg of NaHCO₃Aqueous solution pre-filled with NaHCO₃The aqueous solution is stored in the tank 11, transferred to the reactor 13 by the first transfer pump 17, and the system is started, the temperature of the reactor 13 is set to 78 ℃, and the pressure is setSetting the pressure at 0.8MPa, adding NaHCO₃The aqueous solution is fed to the interior of the reactor 13, while ethylene oxide is fed to the interior of each micro-interface generator 131 of the micro-interface unit via an ethylene oxide feed conduit.

The micro-interface generator 131 breaks the ethylene oxide into micro-bubbles with micron-scale dimensions, and releases the micro-bubbles into the reactor, so that the ethylene oxide and NaHCO are in the micro-bubbles state₃Aqueous solution is fully contacted, NaHCO₃The aqueous solution reacts with ethylene oxide to produce ethylene glycol and also produces byproducts such as methanol and acetaldehyde.

The reacted reaction product is conveyed to a light component removing tower 14 to remove light components, the light components and heavy components are separated, the light components such as methanol, acetaldehyde and the like are distilled out from a light component outlet 141 at the top of the tower, and NaHCO is used₃The heavy components such as the aqueous solution and the ethylene glycol are left at the bottom of the tower, and the heavy components are conveyed out from a heavy component outlet 142 to a rectifying tower 15, and NaHCO is used₃The aqueous solution is left at the bottom of the rectifying tower 15, is discharged from a raw material circulating outlet 152 arranged at the bottom of the rectifying tower 15, and is conveyed back to the reactor 13 through a second conveying pump 18 to realize the recycling, the glycol is distilled off from the top of the rectifying tower 15, one part of the glycol is refluxed through an overhead condenser 151, and the other part of the glycol is directly extracted to a glycol storage tank 16 for storage.

In the above embodiment, the micro-interface generator 131 converts the pressure energy of the gas and/or the kinetic energy of the liquid into the surface energy of the bubbles and transmits the surface energy to the bubbles, so that the bubbles are broken into micro-bubbles with a diameter of 1 μm or more and a diameter of less than 1mm, and the micro-bubbles are divided into a pneumatic micro-interface generator, a hydraulic micro-interface generator and a gas-liquid linkage micro-interface generator according to an energy input mode or a gas-liquid ratio, wherein the pneumatic micro-interface generator is driven by gas, and the input gas amount is much larger than the liquid amount; the hydraulic micro-interface generator is driven by liquid, and the input air quantity is generally smaller than the liquid quantity; the gas-liquid linkage type micro-interface generator is driven by gas and liquid at the same time, and the input gas amount is close to the liquid amount. The micro-interface generator 131 is one or more of a pneumatic micro-interface generator, a hydraulic micro-interface generator and a gas-liquid linkage micro-interface generator.

In order to increase the dispersion and mass transfer effects, additional micro-interface generators 131 may be additionally provided, the installation position is not limited, the micro-interface generators may be external or internal, and the micro-interface generators may be installed on the side wall inside the reactor in a relative arrangement manner when the micro-interface generators are internal, so as to realize the opposite collision of micro-bubbles coming out from the outlet of the micro-interface generator 131.

In the above embodiment, the number of the pump bodies is not specifically required, and the pump bodies may be arranged at corresponding positions as required.

Finally, the yield of ethylene glycol is detected, and the conversion rate of ethylene oxide is calculated to be 98%.

Example 2

Referring to fig. 2, in this embodiment, the number of the micro-interface generators 131, the temperature of the system, and the pressure are different from those in embodiment 1, the number of the micro-interface generators 131 in this embodiment is 4, each 2 is divided into two groups, the two groups are sequentially arranged from top to bottom, 2 of each group of the micro-interface generators 131 are connected in series, the two groups are connected in parallel, the temperature of the system is set to 95 ℃, and the pressure is set to 2.0 MPa. Ethylene glycol production was monitored and ethylene oxide conversion was calculated to be 97%.

Example 3

Referring to fig. 3, the number of the micro-interface generators 131, the temperature of the system, and the pressure of the system are different in this embodiment from those in embodiment 1, the number of the micro-interface generators 131 in this embodiment is 4, and the micro-interface generators 131 are sequentially arranged from top to bottom, the system temperature is 86.5 ℃, and the pressure is 1.4 MPa. Ethylene glycol production was monitored and ethylene oxide conversion was calculated to be 97%.

Comparative example 1

The specific procedure was identical to that of example 1, except that the micro-interface generator 131 was not provided and the ethylene oxide and NaHCO were directly introduced₃The aqueous solution is simultaneously introduced into the reactor 1 for reaction. Ethylene glycol production was monitored and ethylene oxide conversion was calculated to be 88%.

Comparative example 2

The specific procedure was in accordance with example 2, but not limited theretoA micro-interface generator 131 is provided to directly mix ethylene oxide and NaHCO₃The aqueous solution is simultaneously introduced into the reactor 1 for reaction. Ethylene glycol production was monitored and ethylene oxide conversion was calculated to be 86%.

Comparative example 3

The specific procedure was the same as in example 3 except that the micro-interface generator 131 was not provided and the ethylene oxide and NaHCO were directly introduced₃The aqueous solution is simultaneously introduced into the reactor 1 for reaction. Ethylene glycol production was monitored and ethylene oxide conversion was calculated to be 83%.

It is apparent that comparing examples 1-3 and comparative examples 1-3 above, it can be seen that the use of a micro-interfacial generator inside reactor 1 in the examples increases the ethylene oxide and NaHCO content of the reaction process₃The mass transfer area of the phase boundary between the aqueous solutions enables the ethylene oxide to be in a micro-bubble state with NaHCO₃The aqueous solution was contacted sufficiently and then reacted, so that the yield of the product ethylene glycol was significantly higher than that of the comparative example.

In a word, after the micro-interface generator is arranged in the reactor, on one hand, the reaction system can disperse and crush the materials into micro bubbles, so that the phase interface area between a gas phase and a liquid phase is increased, the mass transfer space is fully satisfied, the retention time of the gas in the liquid phase is increased, the energy consumption is reduced, and the reaction efficiency is improved; on the other hand, the operation temperature and pressure in the reactor are reduced, and the safety and stability of the whole reaction system are improved.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.