阅读说明：本技术 一种氯乙醇法制备乙二醇的智能微界面反应系统及方法 (Intelligent micro-interface reaction system and method for preparing ethylene glycol by chloroethanol 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 2020-12-16 设计创作，主要内容包括：一种氯乙醇法制备乙二醇的智能微界面反应系统,包括：主物料反应器、结晶器、第一回用反应器、第二回用反应器和智能控制系统；所述主物料反应器连接有碳酸氢钠存储罐和氯乙醇存储罐,所述主物料反应器反应后的产物进入到所述结晶器中,所述结晶器连接有所述第一回用反应器和所述第二回用反应器,所述第一回用反应器和所述第二回用反应器相互并联；所述第一回用反应器内设置有第一氨气微界面发生器、二氧化碳微界面发生器,所述第二回用反应器内设置有第二氨气微界面发生器、分流型微界面发生器；所述智能控制系统控制所述第一回用反应器和所述第二回用反应器里的反应速率。本发明的反应系统降低了反应过程的成本,强化了反应的效率。(An intelligent micro-interface reaction system for preparing ethylene glycol by a chlorohydrin method comprises: the system comprises a main material reactor, a crystallizer, a first recycling reactor, a second recycling reactor and an intelligent control system; the main material reactor is connected with a sodium bicarbonate storage tank and a chlorohydrin storage tank, a product obtained after reaction of the main material reactor enters the crystallizer, the crystallizer is connected with the first recycling reactor and the second recycling reactor, and the first recycling reactor and the second recycling reactor are mutually connected in parallel; a first ammonia micro-interface generator and a carbon dioxide micro-interface generator are arranged in the first recycling reactor, and a second ammonia micro-interface generator and a split-flow type micro-interface generator are arranged in the second recycling reactor; the intelligent control system controls the reaction rate in the first recycle reactor and the second recycle reactor. The reaction system of the invention reduces the cost of the reaction process and enhances the reaction efficiency.)

1. An intelligent micro-interface reaction system for preparing ethylene glycol by a chlorohydrin method is characterized by comprising the following steps: the system comprises a main material reactor, a crystallizer, a first recycling reactor, a second recycling reactor and an intelligent control system;

the main material reactor is connected with a sodium bicarbonate storage tank and a chlorohydrin storage tank, a product obtained after reaction of the main material reactor enters the crystallizer, the crystallizer is connected with the first recycling reactor and the second recycling reactor, and the first recycling reactor and the second recycling reactor are mutually connected in parallel;

a first ammonia micro-interface generator and a carbon dioxide micro-interface generator are arranged in the first recycling reactor, the first ammonia micro-interface generator is connected with an ammonia gas inlet pipeline, and the carbon dioxide micro-interface generator is connected with a carbon dioxide gas inlet pipeline;

a second ammonia gas micro-interface generator and a split-flow type micro-interface generator are arranged in the second recycling reactor, the second ammonia gas micro-interface generator is connected with the ammonia gas inlet pipeline, and the split-flow type micro-interface generator is connected with the carbon dioxide gas inlet pipeline;

the first recycling reactor and the second recycling reactor are connected with the main material reactor to return the generated sodium bicarbonate to the main material reactor;

the intelligent control system comprises a central processing unit, an automatic monitoring module, an automatic adjusting module, a mutual control station and an operator station; the central processor is connected with the automatic monitoring module, the automatic adjusting module and the mutual control station; the mutual control station is connected with the operator station;

the automatic detection module comprises a sodium bicarbonate concentration detection module and a sodium chloride concentration monitoring module, and the automatic adjustment module comprises a dissolver dissolution rate adjustment module.

2. The reaction system of claim 1, wherein the first ammonia gas micro-interface generator is arranged at the bottom of the first recycling reactor, the carbon dioxide micro-interface generator is arranged at the middle of the first recycling reactor, the second ammonia gas micro-interface generator is arranged at the bottom of the second recycling reactor, and the split-flow type micro-interface generator is arranged at the top of the second recycling reactor.

3. The reaction system of claim 1, wherein a gas distribution channel is arranged between the first ammonia gas micro-interface generator and the carbon dioxide micro-interface generator, a gas outlet of the carbon dioxide micro-interface generator faces downwards and is connected with the gas distribution channel, and a gas outlet of the first ammonia gas micro-interface generator faces upwards and is connected with the gas distribution channel.

4. The reaction system of claim 3, wherein the gas distribution channel is provided with vent holes, and the vent holes are uniformly distributed on the side wall of the gas distribution channel.

5. The reaction system of claim 1 wherein the split-flow channel of the split-flow type micro-interface generator is directed upward.

6. The reaction system of claims 1 to 5, wherein a dissolver is arranged at the top part in the first recycling reactor for redissolving the solid sodium chloride separated out from the crystallizer in water, and a dissolver is arranged at the middle part in the second recycling reactor for redissolving the solid sodium chloride separated out from the crystallizer in water.

7. The reaction system of claim 6, wherein a jet pipe is arranged around the dissolver at the top of the first loop reactor for jetting the dissolved sodium chloride solution into the first loop reactor.

8. The reaction system of claim 6, wherein a delivery pipe is arranged between the split-flow type micro-interface generator and the dissolver in the middle of the second recycling reactor for delivering the solvent in the dissolver to the split-flow type micro-interface generator.

9. The intelligent micro-interface reaction method for preparing the ethylene glycol by using the chloroethanol as claimed in any one of claims 1 to 8, is characterized by comprising the following steps:

(A) reacting sodium bicarbonate, chlorohydrin and water to obtain ethylene glycol and a byproduct sodium chloride, and purifying the hexanediol;

(B) and (3) carrying out micro-interfacial dispersion and crushing on ammonia gas and carbon dioxide in advance, and reacting the byproduct sodium chloride with the ammonia gas and the carbon dioxide after the crushing and the dispersion to obtain sodium bicarbonate for reuse.

10. The method according to claim 9, wherein the reaction temperature in the step (A) is 80 to 105 ℃ and the reaction temperature in the step (B) is 5 to 10 ℃.

Technical Field

The invention relates to the field of ethylene glycol preparation, in particular to an intelligent micro-interface reaction system and method for preparing ethylene glycol by a chlorohydrin method.

Background

Ethylene Glycol (Ethylene Glycol), also known as Ethylene Glycol, is an important petrochemical organic raw material. The chemical reaction of the glycol is similar to that of the monohydric alcohol, and can perform typical reactions of many alcohols, such as esterification reaction, dehydration reaction, etherification reaction and the like, and the reaction product is mainly used for producing polyester fibers, polyester plastics and the like, is widely used for producing lubricants, plasticizers, nonionic surfactants, explosives and the like, and can be directly used as an antifreeze and a coolant for preparing engines. The traditional process utilizes the reaction of chloroethanol and alkali to generate cyclic chloroethane, and then the cyclic chloroethane is hydrolyzed to obtain ethylene glycol. The modern process is to react chloroethanol in weak alkali aqueous solution to directly synthesize glycol, and then to separate the glycol to obtain pure glycol. The modern process has higher requirement on the temperature during the reaction, and the preparation difficulty and the cost are improved.

Therefore, there is a need for improving the preparation of ethylene glycol by the chlorohydrin method, and increasing the purity and difficulty of ethylene glycol preparation by the chlorohydrin method by adding a new technology.

In addition, with the development of informatization becoming faster and faster, the reaction of an intelligent system becomes more and more extensive, and moreover, by adopting a manual control mode, mistakes are easy to make and the labor cost is higher.

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

Disclosure of Invention

The first purpose of the invention is to provide an intelligent micro-interface reaction system for preparing ethylene glycol by a chlorohydrin method, which comprises a first recycle reactor and a second recycle reactor, wherein sodium chloride is recovered to generate sodium bicarbonate, and the sodium bicarbonate is returned to a main material reactor for continuous reaction, so that the cost is saved, and a micro-interface generator is arranged in the first recycle reactor and the second recycle reactor to efficiently break an incoming gas phase into micron-sized bubbles, and the micron-sized bubbles are dispersed to each of the first recycle reactor and the second recycle reactor to form a micro-interface system, so that the gas-liquid internal phase interface area of the reaction is increased by tens of times, and the mass transfer rate of the gas phase to the liquid phase is greatly increased.

Meanwhile, the reaction system can realize the whole process of acquisition, analysis and correction of the system operation parameters, and an operator can manually close the system under dangerous conditions, so that the labor cost is reduced, and meanwhile, the safety guarantee is obtained.

The second purpose of the invention is to provide a method for preparing ethylene glycol by adopting the reaction system, the method is simple and convenient to operate, the obtained ethylene glycol has high purity and high product quality, and the method is widely popularized and applied.

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

the invention provides an intelligent micro-interface reaction system for preparing ethylene glycol by a chlorohydrin method, which comprises the following steps: the system comprises a main material reactor, a crystallizer, a first recycling reactor, a second recycling reactor and an intelligent control system;

the main material reactor is connected with a sodium bicarbonate storage tank and a chlorohydrin storage tank, a product obtained after reaction of the main material reactor enters the crystallizer, the crystallizer is connected with the first recycling reactor and the second recycling reactor, and the first recycling reactor and the second recycling reactor are mutually connected in parallel;

a first ammonia micro-interface generator and a carbon dioxide micro-interface generator are arranged in the first recycling reactor, the first ammonia micro-interface generator is connected with an ammonia gas inlet pipeline, and the carbon dioxide micro-interface generator is connected with a carbon dioxide gas inlet pipeline;

a second ammonia gas micro-interface generator and a split-flow type micro-interface generator are arranged in the second recycling reactor, the second ammonia gas micro-interface generator is connected with the ammonia gas inlet pipeline, and the split-flow type micro-interface generator is connected with the carbon dioxide gas inlet pipeline;

the first recycling reactor and the second recycling reactor are connected with the main material reactor to return the generated sodium bicarbonate to the main material reactor;

the intelligent control system comprises a central processing unit, an automatic monitoring module, an automatic adjusting module, a mutual control station and an operator station; the central processor is connected with the automatic monitoring module, the automatic adjusting module and the mutual control station; the mutual control station is connected with the operator station;

the automatic detection module comprises a sodium bicarbonate concentration detection module and a sodium chloride concentration monitoring module, and the automatic adjustment module comprises a dissolver dissolution rate adjustment module.

In a reaction system for preparing ethylene glycol from chloroethanol in the prior art, chloroethanol and sodium bicarbonate are subjected to hydrolysis reaction to generate ethylene glycol and sodium chloride, and the sodium chloride is filtered out after being precipitated in a crystallizer, so that waste of raw materials is caused; and when sodium chloride is used for generating sodium bicarbonate, the sodium bicarbonate generating efficiency is low because the phase boundary mass transfer area between ammonia gas and carbon dioxide and the sodium chloride solution is small, and the contact time is short. The present invention has been made to solve the above problems, and provides a reaction system in which a first recycle reactor and a second recycle reactor are disposed below a crystallizer to collect sodium chloride precipitate discharged from the recycle crystallizer, and reaction efficiency is improved by adding a micro-interface generator to the first recycle reactor and the second recycle reactor.

The main material reactor is connected with a sodium bicarbonate storage tank and a chlorohydrin storage tank, the sodium bicarbonate and the chlorohydrin react in the main material reactor to generate ethylene glycol and sodium chloride and are conveyed to a crystallizer, sodium chloride crystals are separated out after the crystallizer is cooled, and the sodium chloride crystals are discharged from the crystallizer and then enter a first recycling reactor and a second recycling reactor.

A first ammonia micro-interface generator is arranged in the first recycling reactor and used for crushing and dispersing ammonia gas conveyed by an ammonia gas inlet pipeline into ammonia gas micro-bubbles, and a carbon dioxide micro-interface generator is arranged in the first recycling reactor and used for crushing and dispersing carbon dioxide conveyed by a carbon dioxide gas inlet pipeline into carbon dioxide micro-bubbles; the second recycling reactor is internally provided with a shunting type micro-interface generator for crushing and dispersing carbon dioxide conveyed by a carbon dioxide inlet pipeline into carbon dioxide micro-bubbles, and the second recycling reactor is internally provided with a second ammonia micro-interface generator for crushing and dispersing ammonia conveyed by an ammonia inlet pipeline into ammonia micro-bubbles. The ammonia gas and the carbon dioxide are broken and dispersed into micro bubbles by the micro interface generator, so that the mass transfer area of phase boundaries among the ammonia gas, the carbon dioxide and the sodium chloride solution is increased, the reaction efficiency of sodium bicarbonate generation is enhanced, and the reaction efficiency of ethylene glycol generation is also enhanced.

And returning the sodium bicarbonate generated by the first recycling reactor and the second recycling reactor which are connected in parallel to each other to the main material reactor.

The reaction system also comprises an intelligent control system, wherein the intelligent control system is connected with the first recycling reactor and the second recycling reactor which are connected in parallel, controls the rate of dissolving sodium chloride in the dissolver, adjusts the concentration of sodium chloride in the first recycling reactor and the second recycling reactor, and controls the reaction rate.

In a word, the first recycling reactor and the second recycling reactor are added into the reaction system, so that the waste sodium chloride is recycled to generate the sodium bicarbonate, and the cost is saved; the micro-interface generators are arranged in the first recycling reactor and the second recycling reactor, so that the phase boundary mass transfer area between ammonia gas, carbon dioxide and sodium chloride solution is increased, the ammonia gas, the carbon dioxide and the sodium chloride solution are fully contacted, the reaction efficiency is improved, and the reaction time is shortened; an intelligent control module is added into the reaction system to control the rate of the sodium bicarbonate generated in the first recycling reactor and the second recycling reactor.

Preferably, the first ammonia gas micro-interface generator is arranged at the bottom of the first recycling reactor, the carbon dioxide micro-interface generator is arranged in the middle of the first recycling reactor, the second ammonia gas micro-interface generator is arranged at the bottom of the second recycling reactor, and the split-flow type micro-interface generator is arranged at the top of the second recycling reactor. In the invention, a first ammonia micro-interface generator is arranged at the bottom of a first recycling reactor, a carbon dioxide micro-interface generator is arranged at the middle part of the first recycling reactor, a second ammonia micro-interface generator is arranged at the bottom of a second recycling reactor, a flow-splitting type micro-interface generator is arranged at the top of the second recycling reactor, because the density of ammonia is less than that of carbon dioxide, the rising speed of ammonia in a solution is faster than that of carbon dioxide, the micro-interface generators for introducing ammonia are arranged at the bottoms of the first recycling reactor and the second recycling reactor, the micro-interface generators for introducing carbon dioxide are respectively arranged at the middle part of the first recycling reactor or at the top of the second recycling reactor, therefore, the reaction time of ammonia and carbon dioxide is prolonged in the reaction process, and the reaction efficiency of sodium bicarbonate is improved.

Preferably, a gas distribution channel is arranged between the first ammonia gas micro-interface generator and the carbon dioxide micro-interface generator, a gas outlet of the carbon dioxide micro-interface generator is arranged downwards and connected with the gas distribution channel, and a gas outlet of the first ammonia gas micro-interface generator is arranged upwards and connected with the gas distribution channel.

Preferably, the air distribution channel is provided with air exhaust holes, and the air exhaust holes are uniformly distributed on the side wall of the air distribution channel.

According to the invention, a gas distribution channel is also arranged between the first ammonia gas micro-interface generator and the carbon dioxide micro-interface generator, a gas outlet of the carbon dioxide micro-interface generator is arranged downwards and connected with the gas distribution channel, and a gas outlet of the first ammonia gas micro-interface generator is arranged upwards and connected with the gas distribution channel. Set up the gas distribution channel between two little interface generator, be provided with the exhaust hole on the gas distribution channel, exhaust hole evenly distributed is used for the microbubble homodisperse who comes out in the little interface generator to first back reactor and second reactor at gas distribution channel lateral wall. The gas outlet of the carbon dioxide micro-interface generator is downwards arranged and connected with the gas distribution channel, and the gas outlet of the first ammonia micro-interface generator is upwards arranged and connected with the gas distribution channel, so that carbon dioxide micro-bubbles are easier to downwards react with ammonia micro-bubbles because the density of carbon dioxide is higher than that of ammonia.

Preferably, the flow dividing channel of the flow dividing type micro-interface generator faces upwards. The flow dividing channel of the flow dividing type micro-interface generator is arranged upwards, so that micro bubbles in the second recycling reactor rise and gather at the top of the second recycling reactor, the flow dividing channel faces upwards, sodium chloride solution from the flow dividing type micro-interface generator flows upwards to divide and impact the top of the second recycling reactor, the micro bubbles at the top are dispersed and conveyed downwards, meanwhile, circulating circulation of solution in the second recycling reactor is formed, the phase boundary mass transfer area between the solution and the micro bubbles is increased, and the reaction efficiency of sodium bicarbonate generation is accelerated.

Preferably, a dissolver is arranged at the top of the first recycling reactor and used for redissolving the solid sodium chloride precipitated from the crystallizer in water, and the dissolver is arranged in the middle of the second recycling reactor and used for redissolving the solid sodium chloride precipitated from the crystallizer in water.

Preferably, a jet flow pipeline is arranged around the dissolver at the top of the first loop reactor for jetting the dissolved sodium chloride solution into the first loop reactor.

Preferably, a conveying pipeline is arranged between the split flow type micro-interface generator and the dissolver in the middle of the second recycling reactor and is used for conveying the solvent in the dissolver to the split flow type micro-interface generator.

The dissolvers are arranged at the top of the first recycling reactor and the middle part of the second recycling reactor and are used for re-dissolving the solid sodium chloride precipitated from the crystallizer into water. A jet flow pipeline is arranged around the dissolver in the first recycling reactor and used for jetting the dissolved sodium chloride solution into the first recycling reactor, and the ammonia gas microbubbles and the carbon dioxide microbubbles which are originally gathered at the top return to the middle part or the bottom of the first recycling reactor along with the jetting of the sodium chloride solution, so that the ammonia gas microbubbles and the carbon dioxide microbubbles fully react with the sodium chloride solution, and the reaction efficiency is enhanced; the dissolver in the second recycling reactor is arranged in the middle of the second recycling reactor and is provided with a conveying pipeline for connecting the dissolver in the second recycling reactor with the split-flow type micro-interface generator, the sodium chloride solution dissolved out by the dissolver in the second recycling reactor enters the split-flow type micro-interface generator, the sodium chloride solution is split upwards through a split-flow channel of the split-flow type micro-interface generator, impacts the micro-bubbles gathered at the top of the second recycling reactor, the micro-bubbles at the top are dispersed and conveyed downwards, meanwhile, the circulating circulation of the solution in the second recycling reactor is formed, the phase boundary mass transfer area between the solution and the micro-bubbles is increased, and the reaction efficiency of sodium bicarbonate generation is accelerated.

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 numbers CN201610641119.6, CN201610641251.7, 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.

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 micro-interface generators belong to the pneumatic type micro-interface generator, some micro-interface generators belong to the hydraulic type micro-interface generator, and some micro-interface generators belong to the gas-liquid linkage type micro-interface generator, the difference between the types is mainly selected according to the different specific working conditions, and the connection between the micro-interface generator and the reactor and other devices, including the connection structure and the connection position, is determined according to the structure of the micro-interface generator, which is not limited.

In addition, the invention also provides an intelligent micro-interface reaction method for preparing ethylene glycol from chloroethanol, which comprises the following steps:

(A) reacting sodium bicarbonate, chlorohydrin and water to obtain ethylene glycol and a byproduct sodium chloride, and purifying hexanediol;

(B) ammonia gas and carbon dioxide are dispersed and crushed at a micro interface, and the sodium chloride reacts with the crushed and dispersed ammonia gas micro bubbles and carbon dioxide micro bubbles to obtain sodium bicarbonate;

(C) the sodium bicarbonate is returned to step (a) and re-reacted with chloroethanol.

Preferably, the reaction temperature of the step (A) is 80-105 ℃, and the reaction temperature of the step (B) is 5-10 ℃.

Compared with the method for preparing the ethylene glycol by using the chloroethanol in the prior art, the method disclosed by the invention can be used for collecting and recycling the waste sodium chloride, and the production efficiency of the sodium bicarbonate is improved, so that the production efficiency of the ethylene glycol is improved.

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

(1) according to the invention, the first recycling reactor and the second recycling reactor which are connected in parallel are arranged, so that the waste sodium chloride is recycled, and the cost is saved;

(2) the intelligent control system can control the rate of dissolving sodium chloride by the dissolver and the generation rate of sodium bicarbonate, thereby controlling the generation rate of ethylene glycol;

(3) according to the reaction system, the micro-interface generators arranged in the first recycling reactor and the second recycling reactor are used for efficiently crushing and dispersing the entering gas phase into micron-sized bubbles, and the micron-sized bubbles are dispersed into the solvent to form a micro-interface system, so that the mass transfer rate from the gas phase to the liquid phase is greatly increased.

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 diagram of an intelligent micro-interface reaction system for preparing ethylene glycol by a chlorohydrin method according to an embodiment of the present invention.

Wherein:

101-a sodium bicarbonate storage tank; 102-a chlorohydrin storage tank;

103-a carbon dioxide inlet duct; 104-ammonia gas inlet pipe;

20-main feed reactor; 30-a crystallizer;

40-first recycle reactor; 401-a second recycle reactor;

41-carbon dioxide micro-interface generator; 42-a first ammonia gas micro-interface generator;

43-gas distribution channel; 431-exhaust hole;

45-split flow type micro-interface generator; 451-a flow-splitting channel;

46-second ammonia gas micro-interface generator 44-dissolver;

441-jet flow duct; 442-a delivery conduit;

50-a distillation column; 60-a filter;

70-a rectifying tower; 80-a glycol storage tank;

90-intelligent control system

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

Examples

Referring to fig. 1, a micro-interface reaction system for preparing ethylene glycol from chlorohydrin according to an embodiment of the present invention mainly includes a sodium bicarbonate storage tank 101, a chlorohydrin storage tank 102, a carbon dioxide gas inlet pipeline 103, an ammonia gas inlet pipeline 104, a main material reactor 20, a crystallizer 30, a first recycle reactor 40, a second recycle reactor 401, a distillation tower 50, a filter 60, a rectification tower 70, and an ethylene glycol storage tank 80. The sodium bicarbonate storage tank 101 and the chlorohydrin storage tank 102 are connected with the main material reactor 20 for delivering raw materials of sodium bicarbonate and chlorohydrin to the main material reactor 20, wherein the sodium bicarbonate and the chlorohydrin react in the main material reactor 20 to generate ethylene glycol and byproduct sodium chloride, and the reaction temperature is 100 ℃. The ethylene glycol and sodium chloride generated by the reaction are conveyed to a crystallizer 30, the solution is cooled in the crystallizer 30 to separate out sodium chloride crystals, and the purified ethylene glycol enters a distillation tower 50.

The discharged sodium chloride crystals enter the first recycle reactor 40 and the second recycle reactor 401 which are connected in parallel with each other. The discharged sodium chloride crystals enter a dissolver 44 at the top of the first recycling reactor 40 to be dissolved into a sodium chloride solution, a jet flow pipeline 441 is arranged around the dissolver 44 at the top of the first recycling reactor 40, and the sodium chloride solution is sprayed into the first recycling reactor 40 through the jet flow pipeline 441; the discharged sodium chloride crystals also enter the dissolver 44 in the middle of the second recycling reactor 401 to be dissolved and become sodium chloride solution, a conveying pipeline 442 is further arranged between the dissolver 44 in the middle of the second recycling reactor 401 and the split-flow type micro-interface generator 45, the sodium chloride solution is conveyed to the split-flow type micro-interface generator 45 through the conveying pipeline 442, and then the sodium chloride solution is split to the top of the second recycling reactor 401 through a split-flow channel 451 on the split-flow type micro-interface generator 45 and impacts top micro-bubbles to disperse the top micro-bubbles.

Wherein, the first recycling reactor 40 is also provided with a carbon dioxide micro-interface generator 41 and a first ammonia micro-interface generator 42, and the first recycling reactor 40 is also provided with a carbon dioxide inlet pipeline 103 and an ammonia inlet pipeline 104. The carbon dioxide gas inlet pipe 103 passes through the side wall of the first recycling reactor 40 and is connected with the carbon dioxide micro-interface generator 41 to convey carbon dioxide to the carbon dioxide micro-interface generator 41, and the ammonia gas inlet pipe 104 passes through the side wall of the first recycling reactor 40 and is connected with the first ammonia gas micro-interface generator 42 to convey ammonia gas to the first ammonia gas micro-interface generator 42. The carbon dioxide micro-interface generator 41 is arranged in the middle of the first recycling reactor 40, the first ammonia micro-interface generator 42 is arranged at the bottom of the first recycling reactor 40, and the gas distribution channel 43 is vertically arranged between the carbon dioxide micro-interface generator 41 and the first ammonia micro-interface generator 42.

The upper end of the gas distribution channel 43 is connected with the gas outlet of the carbon dioxide micro-interface generator 41, and the lower end is connected with the gas outlet of the first ammonia micro-interface generator 42. The carbon dioxide microbubbles from the carbon dioxide micro-interface generator 41 and the ammonia microbubbles from the first ammonia micro-interface generator 42 are fully mixed in the gas distribution channel 43 and then discharged from the gas outlet 431 into the first recycling reactor 40. Since the gas discharging holes 431 are uniformly distributed on the gas distributing channel 43, the discharged ammonia gas microbubbles and carbon dioxide gas microbubbles are uniformly dispersed into the first recycling reactor 40. The ammonia, carbon dioxide and sodium chloride solution are fully reacted in the first recycle reactor 40 to produce sodium bicarbonate, which is returned to the main feed reactor 20 to react again with the chlorohydrin.

Wherein, the second recycling reactor 401 is also provided with a split-flow type micro-interface generator 45 and a second ammonia micro-interface generator 46, the split-flow type micro-interface generator 45 is connected with the carbon dioxide gas inlet pipeline 103, and the second ammonia micro-interface generator 46 is connected with the ammonia gas inlet pipeline 104. The upper side of the shunting-type micro-interface generator 45 is also provided with a shunting channel 451 with an upward direction. A conveying pipeline 442 is further arranged between the dissolver 44 and the split-flow type micro-interface generator 45 in the middle of the second recycling reactor 401, the sodium chloride solution is conveyed into the split-flow type micro-interface generator 45 through the conveying pipeline 442, and then the sodium chloride solution is split to the top of the second recycling reactor 401 through a splitting channel 451 on the split-flow type micro-interface generator 45 and impacts micro-bubbles at the top to disperse the micro-bubbles, so that the mass transfer area of a phase boundary between gas and liquid is increased. The ammonia gas, the carbon dioxide and the sodium chloride solution are fully reacted in the second recycling reactor 401 to generate sodium bicarbonate, and the sodium bicarbonate is returned to the main material reactor 20 to react with the chloroethanol again.

The intelligent control system 90 comprises a central processing unit, an automatic detection module, an automatic adjustment module, an inter-control station and an operator station, when the intelligent system normally operates, the sodium bicarbonate concentration detection module and the sodium chloride concentration detection module in the automatic detection module detect the concentration of sodium bicarbonate and the concentration of sodium chloride and submit the concentration of sodium bicarbonate and the concentration of sodium chloride to the central processing unit for analysis, the central processing unit sends an instruction to the automatic adjustment module after analysis, the automatic adjustment module adjusts the rate of dissolving sodium chloride by a dissolver so as to guarantee the operation of reaction, when the intelligent system breaks down, the central processing unit can send an error report to the operator station through the inter-control station, the reaction system is manually closed by an operator, and danger is prevented.

The ethylene glycol generated in the main material reactor 20 is purified by the crystallizer 30 and then enters the distillation tower 50, the distillation tower 50 distills water, the saturation degree of the ethylene glycol is reduced to separate out ethylene glycol crystals, and the precipitated ethylene glycol crystals are collected and then conveyed to the filter 60.

The filter 60 is filled with an acetone solution, and since the ethylene glycol crystals are easily dissolved in the acetone solution, the ethylene glycol crystals collected from the distillation column 50 are all dissolved in the acetone solution. After the ethylene glycol is dissolved in the acetone solution, the acetone solution carries the ethylene glycol into the rectifying tower 70, the rectifying tower 70 converts the acetone into a gas phase by utilizing the fact that the components of the mixture have different volatility, the gas phase is discharged from the top of the tower, the chloroethanol which is not completely reacted is discharged from the bottom of the tower, and the residual ethylene glycol is conveyed to an ethylene glycol storage tank for storage.

In addition, in a specific reaction process, the reaction temperature in the main material reactor 20 is 100 ℃, and the reaction temperature in the first recycle reactor 40 and the second recycle reactor 401 is 5 ℃.

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.