Ethylene glycol production system capable of increasing yield of diethylene glycol and triethylene glycol

Abstract

The invention provides an ethylene glycol production process for increasing the yield of diethylene glycol and triethylene glycol. The ethylene glycol production process comprises an ethylene glycol process module, a diethylene glycol refining unit and a triethylene glycol refining unit, the ethylene glycol process module, the diethylene glycol refining unit and the triethylene glycol refining unit are sequentially communicated through material pipelines, the ethylene glycol process module further comprises an ethylene glycol feeding steam stripping unit and an ethylene glycol dehydration unit, and the ethylene glycol dehydration unit is located at the downstream of the ethylene glycol feeding steam stripping unit; and the outlets at the three positions of the ethylene glycol refining tower reflux pump, the ethylene glycol refining tower side-draw and the diethylene glycol refining tower side-draw are communicated with the ethylene glycol feeding and stripping unit by additionally arranging pipelines. By modifying an ethylene glycol production system device, the yield of ethylene glycol is adjusted and converted into a diethylene glycol product and a triethylene glycol product, so that the problem that the yield of the diethylene glycol product and the yield of the triethylene glycol product cannot be continuously increased due to the limitation of the hydration ratio in the existing ethylene glycol production process is solved.

Description

Technical Field

[0001] The invention relates to the technical field of ethylene glycol production technology, and in particular to an ethylene glycol production system for increasing the production of diethylene glycol and triethylene glycol. Background Art

[0002] The process technology of the ethylene glycol production unit is to produce ethylene oxide by direct oxidation of ethylene, and ethylene oxide and water are directly hydrated in a tubular reactor to produce ethylene glycol. The process patent technology is the patent technology of American Scientific Design Co., Ltd. (SD), and the specific products involved are: monoethylene glycol as the main product, diethylene glycol and triethylene glycol as by-products. In the SD process, ethylene oxide and water react directly (non-catalytically) to obtain ethylene glycol (MONOG), and ethylene oxide also continues to react with ethylene glycol (MEG) to obtain other higher homologues, thereby leading to the formation of diethylene glycol (DEG), triethylene glycol (TEG) and heavy ethylene glycol (POLYETHYLENE GLYCOL, PEG), and the designed hydration ratio is 25:1. As the hydration ratio decreases, the yield of MEG product gradually decreases, and the output of DEG and TEG will gradually increase. However, due to the interlocking limitation of the low absorption water flow rate at the top of the reaction tower, the hydration ratio can only be reduced to 18:1; therefore, the output of DEG and TEG cannot be further increased due to the limitation of the hydration ratio.

[0003] In order to improve the overall production efficiency and increase the MEG content in ethylene oxide (EO) aqueous solution, experiments on increasing the production of DEG and TEG were carried out. At the same time, various parts of the hydration and refining system were analyzed to find out the changes in DEG and TEG products under different MEG concentrations in EO aqueous solution, and the whole process was optimized to achieve increased production of DEG and TEG.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present invention and does not constitute any limitation to the present invention. Summary of the invention

[0005] In view of the shortcomings of the prior art mentioned above, the present invention provides an ethylene glycol production system for increasing the output of diethylene glycol and triethylene glycol. By modifying the ethylene glycol production system device, the output of ethylene glycol can be adjusted and converted into diethylene glycol DEG products and triethylene glycol TEG products, so as to solve the problem that the output of diethylene glycol DEG products and triethylene glycol TEG products in the existing ethylene glycol MEG production system cannot be further increased due to the limitation of hydration ratio.

[0006] The invention provides an ethylene glycol production system for increasing the production of diethylene glycol and triethylene glycol, comprising an ethylene glycol process module, a diethylene glycol refining unit and a triethylene glycol refining unit; the ethylene glycol process module, the diethylene glycol refining unit and the triethylene glycol refining unit are sequentially connected through a material pipeline, the ethylene glycol process module also comprises an ethylene glycol feed stripping unit and an ethylene glycol refining unit, the ethylene glycol refining unit is located on the downstream pipeline of the ethylene glycol feed stripping unit, and a first pipeline is added between the side line extraction outlet pipeline of the ethylene glycol refining unit and the ethylene glycol feed stripping unit to communicate with each other.

[0007] In one embodiment of the present invention, the ethylene glycol process module also includes an ethylene glycol dehydration unit, which is located on the upstream pipeline of the ethylene glycol refining unit. A second pipeline is added between the outlet of the refining tower reflux pump of the ethylene glycol refining unit and the ethylene glycol feed stripping unit.

[0008] In one embodiment of the present invention, a third pipeline is additionally provided between the side line outlet pipeline of the diethylene glycol refining unit and the ethylene glycol feed stripping unit to communicate with each other.

[0009] In one embodiment of the present invention, the outlets of the first pipeline and the second pipeline are connected in parallel to the ethylene glycol feed stripping unit.

[0010] In one embodiment of the present invention, the ethylene glycol process module further includes an ethylene glycol reaction unit and a multi-effect evaporation unit. The ethylene glycol reaction unit and the multi-effect evaporation unit are sequentially connected between the ethylene glycol feed stripping unit and the ethylene glycol dehydration unit through a material pipeline, and a plurality of multi-effect evaporation units are connected in series to form a multi-effect evaporation system.

[0011] In one embodiment of the present invention, a heat exchanger is installed on the side line outlet pipeline of the ethylene glycol refining unit, the outlet pipeline of the heat exchanger is connected to the ethylene glycol product tank, and the inlet of the first pipeline is connected to the outlet pipeline of the heat exchanger.

[0012] In one embodiment of the present invention, the top outlet of the ethylene glycol refining unit is also connected to an ethylene glycol refining reflux unit, the outlet of the ethylene glycol refining reflux unit is connected to the ethylene glycol refining unit, and a reflux pump is installed on the outlet pipeline of the ethylene glycol refining reflux unit, and the inlet of the second pipeline is connected to the outlet pipeline of the reflux pump.

[0013] In one embodiment of the present invention, the outlet of the ethylene glycol refining unit is further connected to an ethylene glycol circulation unit, and the ethylene glycol refining unit is connected to the diethylene glycol refining unit via the ethylene glycol circulation unit.

[0014] In one embodiment of the present invention, a cooler is installed on the side line outlet pipeline of the diethylene glycol refining unit, and the inlet of the third pipeline is connected to the outlet pipeline of the cooler.

[0015] In one embodiment of the present invention, in the ethylene glycol feed stripping unit, the outlet position of the third pipeline is higher than the outlet positions of the first pipeline and the second pipeline connected in parallel.

[0016] The beneficial effects of the present invention are as follows: by modifying the ethylene glycol production system device, the output of ethylene glycol can be adjusted and converted into diethylene glycol DEG products and triethylene glycol TEG products, and the comprehensive benefits of the products can be improved under different market benefits of ethylene glycol, diethylene glycol or triethylene glycol; the output of ethylene glycol MEG products can be reduced and the output of diethylene glycol DEG products and triethylene glycol TEG products can be increased, so as to adapt to market conditions and make the by-products generated in the ethylene glycol production system have high added benefits.

[0017] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present invention, and together with the specification, are used to explain the principles of the present invention. Obviously, the drawings described below are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0019] Figure 1 A schematic diagram of an ethylene glycol production system for increasing the production of diethylene glycol and triethylene glycol according to the present invention;

[0020] Figure 2 It is a schematic diagram of the temperature parameter change of the ethylene glycol reaction unit in one embodiment of the present invention;

[0021] Figure 3 A schematic diagram of the change of the extraction of the ethylene glycol refining unit in one embodiment of the present invention;

[0022] Figure 4 A schematic diagram of the extraction change of a diethylene glycol refining unit in one embodiment of the present invention;

[0023] Figure 5 A schematic diagram of the extraction change of a triethylene glycol refining unit in one embodiment of the present invention;

[0024] Figure 6 It is a schematic diagram of the product quality of ethylene glycol, diethylene glycol and triethylene glycol at different light transmittances in the present invention.

[0025] In the figure: 100, first pipeline; 200, second pipeline; 300, third pipeline; 10, ethylene glycol feed stripping unit; 20, ethylene glycol reaction unit; 30, multi-effect evaporation system; 40, ethylene glycol dehydration unit; 50, ethylene glycol refining unit; 60, ethylene glycol refining reflux unit; 70, ethylene glycol circulation unit; 80, diethylene glycol refining unit; 90, triethylene glycol refining unit. DETAILED DESCRIPTION

[0026] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied by other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the features in the following embodiments and embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present invention are to describe specific specific embodiments, rather than to limit the scope of protection of the present invention.

[0027] See also Figures 1 to 6 . It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any structural modification, change in proportional relationship, or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention. At the same time, the terms such as position and quantitative relationship cited in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0028] See also Figure 1 The present invention provides an ethylene glycol production system for increasing the production of diethylene glycol and triethylene glycol, comprising an ethylene glycol process module, a diethylene glycol refining unit 80 and a triethylene glycol refining unit 90; the ethylene glycol process module, the diethylene glycol refining unit 80 and the triethylene glycol refining unit 90 are sequentially connected through a material pipeline, the ethylene glycol process module also includes an ethylene glycol feed stripping unit 10 and an ethylene glycol refining unit 50, the ethylene glycol refining unit 50 is located on the downstream pipeline of the ethylene glycol feed stripping unit 10, and a first pipeline 100 is added between the side line production outlet pipeline of the ethylene glycol refining unit 50 and the ethylene glycol feed stripping unit 10 to communicate with each other.

[0029] Furthermore, the ethylene glycol process module also includes an ethylene glycol dehydration unit 40, which is located on the upstream pipeline of the ethylene glycol refining unit 50. The top outlet of the ethylene glycol refining unit 50 is connected to the ethylene glycol refining reflux unit 60. The ethylene glycol refining reflux unit 60 is provided with a refining tower reflux pump, and the outlet pipeline of the refining tower reflux pump is connected to the ethylene glycol refining unit 50. A second pipeline 200 is additionally provided between the outlet pipeline of the refining tower reflux pump of the ethylene glycol refining reflux unit 60 and the ethylene glycol feed stripping unit 10.

[0030] Furthermore, a third pipeline 300 is additionally provided between the side line production outlet pipeline of the diethylene glycol refining unit 80 and the ethylene glycol feed stripping unit 10 to communicate with each other.

[0031] Specifically, the ethylene glycol production process adopts the reaction of ethylene oxide and water. During the preparation process, ethylene oxide will continue to react with ethylene glycol to obtain other higher homologues such as diethylene glycol, triethylene glycol and heavy ethylene glycol, among which ethylene glycol is the main product of the preparation process, and diethylene glycol, triethylene glycol and heavy ethylene glycol are by-products of the preparation process. In the embodiment of the present invention, the ethylene glycol process module, the diethylene glycol refining unit 80 and the triethylene glycol refining unit 90 can respectively refer to the process equipment used for the preparation of ethylene glycol, diethylene glycol and triethylene glycol products in the ethylene glycol production system, such as the corresponding stripping tower, dehydration tower, refining tower, reactor and the material pipelines, delivery pumps, heat exchangers and other equipment and facilities connected thereto. Therefore, each unit mentioned in the embodiment of the present invention refers to the corresponding reaction tower and other equipment, which will not be repeated here.

[0032] More specifically, the side line extraction outlet pipeline of the ethylene glycol refining unit 50 is connected to the ethylene glycol feed stripping unit 10 through the added first pipeline 100, that is, the ethylene glycol product initially prepared in the ethylene glycol refining unit 50 is transported to the raw materials of ethylene oxide and water in the ethylene glycol feed stripping unit 10, thereby increasing the content of ethylene glycol in the raw materials for preparation, that is, promoting the reaction between ethylene oxide and ethylene glycol, and increasing the generation of diethylene glycol, triethylene glycol and heavy ethylene glycol homologues. In other words, with the same amount of ethylene oxide and water raw materials, the output of ethylene glycol products is reduced, and the output of diethylene glycol and triethylene glycol homologues is increased.

[0033] Furthermore, the outlet pipeline of the refining tower reflux pump in the ethylene glycol refining reflux unit 60 connected to the outlet of the ethylene glycol refining unit 50 is connected to the ethylene glycol feed stripping unit 10 by adding a second pipeline 200, that is, the ethylene glycol solution in the ethylene glycol refining reflux unit 60 is transported to the raw materials of ethylene oxide and water in the ethylene glycol feed stripping unit 10, and the content of ethylene glycol in the raw materials is further increased, that is, the reaction between ethylene oxide and ethylene glycol is promoted, and the generation of diethylene glycol, triethylene glycol and heavy ethylene glycol homologues is increased. In other words, under the same amount of ethylene oxide and water raw materials, the output of ethylene glycol converted into diethylene glycol and triethylene glycol homologues is increased, and the output of ethylene glycol products is reduced.

[0034] Furthermore, the side line extraction outlet pipeline of the diethylene glycol refining unit 80 is connected to the ethylene glycol feed stripping unit 10 through the third pipeline 300, that is, the diethylene glycol product prepared in the diethylene glycol refining unit 80 is transported to the raw materials of ethylene oxide and water in the ethylene glycol feed stripping unit 10, so as to increase the content of diethylene glycol in the raw materials for preparation, that is, to promote the reaction between ethylene oxide and diethylene glycol, and increase the generation of triethylene glycol and heavy ethylene glycol homologues. In other words, under the same amount of ethylene oxide and water raw materials, the output of diethylene glycol converted into triethylene glycol and other homologues is increased, and the output of ethylene glycol products is reduced.

[0035] See also Figure 1 In one embodiment, a heat exchanger is installed on the side line production outlet pipeline of the ethylene glycol refining unit 50, the outlet pipeline of the heat exchanger is connected to the ethylene glycol product tank, and the inlet of the first pipeline 100 is connected to the outlet pipeline of the heat exchanger. The outlet of the ethylene glycol refining unit 50 is also connected to the ethylene glycol refining reflux unit 60, the outlet of the ethylene glycol refining reflux unit 60 is connected to the ethylene glycol refining unit 50, and a reflux pump is installed on the outlet pipeline of the ethylene glycol refining reflux unit 60, and the inlet of the second pipeline 200 is connected to the outlet pipeline of the reflux pump. A cooler is installed on the side line production outlet pipeline of the diethylene glycol refining unit 80, and the inlet of the third pipeline 300 is connected to the outlet pipeline of the cooler.

[0036] Specifically, in the embodiments of the present invention, please refer to the attached Figure 1 The red line in the middle represents the first pipeline 100, the second pipeline 200 and the third pipeline 300, which are added to reflux the ethylene glycol and diethylene glycol products in the ethylene glycol production system to the initial reaction tower, i.e., the ethylene glycol feed stripping tower. This increases the content of ethylene glycol and diethylene glycol in the ethylene glycol production raw materials, promotes the reaction between them and ethylene oxide to generate diethylene glycol and triethylene glycol products, and thus, with the same amount of raw materials, converts part of the finished products of ethylene glycol and diethylene glycol into finished products of diethylene glycol and triethylene glycol, thereby achieving the purpose of increasing the production of diethylene glycol and triethylene glycol.

[0037] More specifically, the additional first pipeline 100, second pipeline 200 and third pipeline 300 need to cross multiple towers and other equipment facilities in the ethylene glycol production system. By connecting the inlet of the additional pipeline to the outlet pipeline of the pump in the initial material pipeline, the head loss caused by adding long-distance pipelines is overcome by using the head of the delivery pump and the reflux pump to maintain the delivery effect of ethylene glycol and diethylene glycol product materials. On the outlet pipeline of the diethylene glycol refining unit 80 connected to the inlet of the third pipeline 300, a cooler is used to cool the high-temperature liquid flowing from the diethylene glycol refining unit 80 to the outlet pipeline, further cool the diethylene glycol product, and facilitate the delivery of the third pipeline 300. Please refer to the attached Figure 1 , corresponding pumping equipment is also provided upstream of the pipeline where the cooler is located to ensure the transportation of the material products in the pipeline. At the same time, the third pipeline 300 has a longer pipeline length than the first pipeline 100 and the second pipeline 200 added inside the ethylene glycol process module, so corresponding pumping equipment can also be installed on the third pipeline 300 to meet the transportation requirements of the material products (not shown in the drawings). Similarly, pumping equipment can also be arranged in the first pipeline 100 and the second pipeline 200 according to the requirements, which will not be repeated here.

[0038] See also Figure 1 In one embodiment, the ethylene glycol process module further includes an ethylene glycol reaction unit 20 and a multiple-effect evaporation unit. The ethylene glycol reaction unit 20 and the multiple-effect evaporation unit are sequentially connected between the ethylene glycol feed stripping unit 10 and the ethylene glycol dehydration unit 40 through a material pipeline, and a plurality of multiple-effect evaporation units are connected in series to form a multiple-effect evaporation system 30. The outlet of the ethylene glycol refining unit 50 is also connected to an ethylene glycol circulation unit 70, and the ethylene glycol refining unit 50 is connected to a diethylene glycol refining unit 80 through the ethylene glycol circulation unit 70.

[0039] Specifically, in the embodiment of the present invention, the multi-effect evaporation system 30 formed by connecting the multi-effect evaporation units in series divides the evaporation process into multiple stages, so that each stage uses the steam generated in the previous stage and reuses the heat in the steam, thereby improving energy efficiency and reducing energy consumption. In addition, the cascade operation of the series structure is used to reduce the demand for external steam, play a role in effectively concentrating the ethylene glycol solution to achieve product purification, and reduce the amount of wastewater discharged.

[0040] More specifically, on the pipeline upstream of the multiple-effect evaporation system 30, the reaction is carried out in the ethylene glycol reactor in the ethylene glycol reaction unit 20, which is a U-shaped tubular ethylene glycol reactor. Before entering the ethylene glycol reaction unit 20, it needs to be preheated by a heat exchanger, so that the raw liquid output by the ethylene glycol feed stripping unit 10 is usually preheated and reacted to release heat before entering the first "effect" to increase its temperature. In the first effect, the preheated liquid is heated to its boiling point, and the evaporated steam is used to heat the second effect. The steam pressure of the first effect is relatively high, and the steam generated is used to heat the second effect. The second effect (and subsequent effects) continue to use the steam of the previous effect as a heating source to gradually reduce the water concentration in the liquid. The steam pressure of each effect gradually decreases, and finally a concentrated liquid is obtained. In each effect, the generated steam will be condensed into liquid and discharged from the system. After multiple evaporations and concentrations, a liquid product of the desired concentration is finally obtained.

[0041] Thus, in the multiple-effect evaporation system 30, the heat of steam is efficiently utilized by connecting multiple-effect evaporation units in series, and energy consumption is significantly reduced. A large amount of liquid can be processed, production efficiency is improved, and wastewater discharge and other treatment costs are reduced.

[0042] Similarly, the ethylene glycol circulation unit 70 connected between the ethylene glycol refining unit 50 and the diethylene glycol refining unit 80 is used to further separate different components in the material, transport the separated ethylene glycol component to the multiple-effect evaporation system 30 through the material pipeline again, and transport the separated diethylene glycol component directly to the diethylene glycol refining unit 80 to further purify the ethylene glycol and diethylene glycol products respectively.

[0043] See also Figure 1 In one embodiment, the outlets of the first pipeline 100 and the second pipeline 200 are connected in parallel to the ethylene glycol feed stripping unit 10. On the ethylene glycol feed stripping unit 10, the outlet position of the third pipeline 300 is higher than the outlet position of the first pipeline 100 and the second pipeline 200 connected in parallel. By connecting the first pipeline 100 and the second pipeline 200 conveying the same ethylene glycol material in parallel to the ethylene glycol feed stripping unit 10, on the one hand, the total length of the first pipeline 100 and the second pipeline 200 can be reduced, and on the other hand, the re-input ethylene glycol material can be controlled to be located at the same position of the ethylene glycol feed stripping unit 10, which is convenient for controlling the process involved in the ethylene glycol feed stripping unit 10. In the ethylene glycol feed stripping unit 10, the material products are separated by distillation or the like, and the different boiling points of ethylene glycol and diethylene glycol are utilized to control the height position at which they re-enter the ethylene glycol feed stripping unit 10, thereby achieving matching with process steps at different temperatures and optimizing the process steps of diethylene glycol and triethylene glycol components in the ethylene glycol feed stripping unit 10.

[0044] More specifically, in one embodiment of the present invention, the design full-load production capacity of ethylene glycol MEG products of the ethylene glycol production system is 127.8t / h, the production capacity of diethylene glycol DEG products is 10.54t / h, and the production capacity of triethylene glycol TEG products is 0.555t / h. In the case where the economic benefits of ethylene glycol MEG products are weak and the economic benefits added value of diethylene glycol DEG products and triethylene glycol TEG products is high, the economic benefits added value of products can be increased by increasing the output of diethylene glycol DEG products and triethylene glycol TEG products. In this way, after the transformation of the embodiment of the present invention, the production capacity of diethylene glycol DEG products and triethylene glycol TEG products is effectively improved, and the ethylene glycol production system can realize flexible adjustment of product structure, and adjust the product output of ethylene glycol MEG, diethylene glycol DEG triethylene glycol and TEG at any time according to market changes. By increasing the production capacity of diethylene glycol DEG products and triethylene glycol TEG products, the product benefits of the ethylene glycol production system device are improved.

[0045] In one embodiment of the present invention, the device benefit calculation of a single ethylene glycol production system can be referred to: the output of ethylene glycol MEG product decreased by 1.12 t / h, and the expected benefit reduction was 4,381.92 yuan / h; the output of diethylene glycol DEG product increased by about 0.9 t / h, and the estimated benefit was about 4,305 yuan / h; the output of triethylene glycol TEG product increased by 0.100 t / h, and the estimated benefit was about 962.7 yuan / h; the total economic benefit increased by about 885.78 yuan / h, and the daily increase was about 21,258.72 yuan. The two sets of ethylene glycol equipment accumulated an increase of 1.27 million yuan in benefits per month.

[0046] In another embodiment, please refer to the attached Figures 2 to 6The temperature curve of the ethylene glycol reaction unit 20, i.e., the R-520 reactor, fluctuates accordingly with the amount of ethylene glycol and diethylene glycol products added in the first to third pipelines 300, especially the temperature at the elbow end and the front end of the outlet pipe, which increases compared to the original gentle temperature curve, reflecting the changes in the internal material components. Similarly, the output of the ethylene glycol refining unit 50, i.e., the T-620 system, changes with the increase in the amount of ethylene glycol MEG products refluxed to the ethylene glycol feed stripping unit 10, and the output of the ethylene glycol dehydration unit 40, i.e., the T-610 tower bottom, also increases. At the same time, the side line output of the ethylene glycol refining unit 50, i.e., the material output of the side pipeline leading to the ethylene glycol refining reflux unit 60, also increases. On the outlet pipeline of the diethylene glycol refining unit 80 leading to the third pipeline 300, that is, the T-710 side line, as the amount of ethylene glycol MEG product refluxed to the initial reaction tower gradually increases, the material output of each of the ethylene glycol circulation unit 70 and the diethylene glycol refining unit 80 also slowly increases. In the output of the triethylene glycol refining unit 90, that is, the T-720 system, as the amount of ethylene glycol MEG product in the initial reaction tower gradually increases, the material output of the triethylene glycol refining unit 90 also gradually increases. Finally, through the transmittance detection at different wavelengths, as the amount of ethylene glycol MEG product refluxed to the initial reaction tower gradually increases, there is no obvious effect on the transmittance of the final product, which can reflect that the purity quality of the final ethylene glycol, diethylene glycol and triethylene glycol products is maintained.

[0047] In summary, the present invention provides an ethylene glycol production system for increasing the output of diethylene glycol and triethylene glycol. By transforming the ethylene glycol production system device, the output of ethylene glycol can be adjusted and converted into diethylene glycol DEG products and triethylene glycol TEG products. Under the different market benefits of ethylene glycol, diethylene glycol or triethylene glycol, the comprehensive benefits of the products can be improved; and the pipeline structure of the existing production system device is slightly changed, the conversion rate of diethylene glycol DEG products and triethylene glycol TEG products is high, the output of ethylene glycol MEG products is reduced, and the output of diethylene glycol DEG products and triethylene glycol TEG products is increased.

[0048] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. An ethylene glycol production system for increasing the production of diethylene glycol and triethylene glycol, characterized in that: The invention comprises an ethylene glycol process module, a diethylene glycol refining unit (80) and a triethylene glycol refining unit (90); the ethylene glycol process module, the diethylene glycol refining unit (80) and the triethylene glycol refining unit (90) are sequentially connected through a material pipeline; the ethylene glycol process module further comprises an ethylene glycol feed stripping unit (10) and an ethylene glycol refining unit (50); the ethylene glycol refining unit (50) is located on the downstream pipeline of the ethylene glycol feed stripping unit (10); a first pipeline (100) is additionally provided between the side line extraction outlet pipeline of the ethylene glycol refining unit (50) and the ethylene glycol feed stripping unit (10) for communication.

2. The production system according to claim 1, characterized in that: The ethylene glycol process module further comprises an ethylene glycol dehydration unit (40), wherein the ethylene glycol dehydration unit (40) is located on an upstream pipeline of the ethylene glycol refining unit (50), and a second pipeline (200) is additionally provided between the outlet of the refining tower reflux pump of the ethylene glycol refining unit (50) and the ethylene glycol feed stripping unit (10) for communication.

3. The production system according to claim 2, characterized in that: A third pipeline (300) is provided between the side line outlet pipeline of the diethylene glycol refining unit (80) and the ethylene glycol feed stripping unit (10) to communicate with each other.

4. The production system according to claim 3, characterized in that: The outlets of the first pipeline (100) and the second pipeline (200) are connected in parallel to the ethylene glycol feed stripping unit (10).

5. The production system according to claim 1, characterized in that: The ethylene glycol process module further comprises an ethylene glycol reaction unit (20) and a multiple-effect evaporation unit. The ethylene glycol reaction unit (20) and the multiple-effect evaporation unit are sequentially connected between the ethylene glycol feed stripping unit (10) and the ethylene glycol dehydration unit (40) through a material pipeline, and a plurality of the multiple-effect evaporation units are connected in series to form a multiple-effect evaporation system (30).

6. The production system according to claim 1, characterized in that: A heat exchanger is installed on the side line outlet pipeline of the ethylene glycol refining unit (50), the outlet pipeline of the heat exchanger is connected to the ethylene glycol product tank, and the inlet of the first pipeline (100) is connected to the outlet pipeline of the heat exchanger.

7. The production system according to claim 2, characterized in that: The top outlet of the ethylene glycol refining unit (50) is also connected to an ethylene glycol refining reflux unit (60), the outlet of the ethylene glycol refining reflux unit (60) is connected to the ethylene glycol refining unit (50), and a reflux pump is installed on the outlet pipeline of the ethylene glycol refining reflux unit (60), and the inlet of the second pipeline (200) is connected to the outlet pipeline of the reflux pump.

8. The production system according to claim 7, characterized in that: The outlet of the ethylene glycol refining unit (50) is also connected to an ethylene glycol circulation unit (70), and the ethylene glycol refining unit (50) is connected to the diethylene glycol refining unit (80) via the ethylene glycol circulation unit (70).

9. The production system according to claim 3, characterized in that: A cooler is installed on the side line outlet pipeline of the diethylene glycol refining unit (80), and the inlet of the third pipeline (300) is connected to the outlet pipeline of the cooler.

10. The production system according to claim 4, characterized in that: In the ethylene glycol feed stripping unit (10), the outlet position of the third pipeline (300) is higher than the outlet positions of the first pipeline (100) and the second pipeline (200) connected in parallel.

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