An ethylene glycol production system for increasing the production of diethylene glycol and triethylene glycol

Abstract

The present invention provides an ethylene glycol production process for increasing the production of diethylene glycol and triethylene glycol, which includes 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 material pipelines. The ethylene glycol process module further includes an ethylene glycol feed stripping unit and an ethylene glycol dehydration unit, and the ethylene glycol dehydration unit is located downstream of the ethylene glycol feed stripping unit. A pipeline is additionally provided and connected between the outlets at three positions, namely the reflux pump of the ethylene glycol refining column, the side stream extraction of the ethylene glycol refining column, and the side stream extraction of the diethylene glycol refining column, and the ethylene glycol feed stripping unit. By reforming the ethylene glycol production system device, the present invention realizes the adjustment of the output of ethylene glycol and the conversion to diethylene glycol products and triethylene glycol products, so as to solve the problem that the yields of diethylene glycol products and triethylene glycol products in the existing ethylene glycol production process are limited by the hydration ratio and cannot be further increased.

Description

Technical Field

[0001] The present invention relates to the technical field of ethylene glycol production processes, and particularly 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 the direct oxidation method of ethylene to produce ethylene oxide, 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 Scientific Design Company Limited (SD) in the United States. The specific products include: monoethylene glycol as the main product, and diethylene glycol and triethylene glycol as by-products. In the SD process, ethylene oxide and water react directly (non-catalytically) to obtain ethylene glycol (Monoethylene Glycol, MEG). Since ethylene oxide also continues to react with ethylene glycol (MEG) to obtain other higher homologues, the formation of diethylene glycol (Diethylene Glycol, DEG), triethylene glycol (Triethylene Glycol, TEG) and polyethylene glycol (Polyethylene Glycol, PEG) is caused. Its designed hydration ratio is 25:1. As the hydration ratio decreases, the yield of the MEG product gradually decreases, and the yields of DEG and TEG will gradually increase. However, due to the interlock limit of the low absorption water flow rate at the reaction tower top, the hydration ratio can only be reduced to 18:1. Therefore, the yields of DEG and TEG are limited by the hydration ratio and cannot be further increased.

[0003] In order to improve the comprehensive production efficiency and increase the MEG content in the ethylene oxide (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 systems were analyzed to find out the changes in DEG and TEG products at different MEG concentrations in the EO aqueous solution, and the whole process was optimized to achieve an increase in the production of DEG and TEG.

[0004] It should be noted that the information disclosed in the above background art section is only used to strengthen 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 above-mentioned disadvantages of the prior art, the present invention provides an ethylene glycol production system for increasing the production of diethylene glycol and triethylene glycol. By transforming the ethylene glycol production system device, the production of ethylene glycol is adjusted and converted into diethylene glycol DEG products and triethylene glycol TEG products, so as to solve the problem that the yields of diethylene glycol DEG products and triethylene glycol TEG products in the existing ethylene glycol MEG production system are limited by the hydration ratio and cannot be further increased.

[0006] The present invention provides an ethylene glycol production system for increasing the production of diethylene glycol and triethylene glycol. The system 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 connected via a material pipeline. The ethylene glycol process module further comprises an ethylene glycol feed stripping unit and an ethylene glycol refining unit. The ethylene glycol refining unit is located on a downstream pipeline of the ethylene glycol feed stripping unit. A first pipeline is additionally provided between a side line extraction outlet pipeline of the ethylene glycol refining unit and the ethylene glycol feed stripping unit.

[0007] In one embodiment of the present invention, the ethylene glycol process module further 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 provided between the side line outlet pipeline of the diethylene glycol refining unit and the ethylene glycol feed stripping unit.

[0009] In one embodiment of the present invention, the outlets of the first pipeline and the second pipeline are connected in parallel to an 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 via a material pipeline. Several 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 the 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 added benefits of by-products generated in the ethylene glycol production system high.

[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 accompanying drawings are incorporated into and constitute a part of the specification, illustrate 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 it is clear that a person skilled in the art can derive other drawings based on these drawings without inventive effort. 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 Schematic diagram of temperature parameter changes of an ethylene glycol reaction unit in one embodiment of the present invention;

[0021] Figure 3 Schematic diagram of the extraction changes of the ethylene glycol refining unit in one embodiment of the present invention;

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

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

[0024] Figure 6 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, the first pipeline; 200, the second pipeline; 300, the third pipeline; 10, the ethylene glycol feed stripping unit; 20, the ethylene glycol reaction unit; 30, the multi-effect evaporation system; 40, the ethylene glycol dehydration unit; 50, the ethylene glycol refining unit; 60, the ethylene glycol refining reflux unit; 70, the ethylene glycol circulation unit; 80, the diethylene glycol refining unit; 90, the triethylene glycol refining unit. Detailed implementation manners

[0026] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. It should also be understood that the terms used in the embodiments of the present invention are for describing specific specific implementation manners, rather than for limiting the protection scope of the present invention.

[0027] Please refer to Figures 1 to 6 . It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limited conditions under which the present invention can be implemented. Therefore, they do not have technical essential meanings. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention. At the same time, the terms such as the positions and quantity relationships cited in this specification are only for the convenience of clear narration, rather than for limiting the scope under which the present invention can be implemented. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope within which the present invention can be implemented.

[0028] Please refer to Figure 1 , the present invention provides an ethylene glycol production system for increasing the production of diethylene glycol and triethylene glycol, including 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 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. A first pipeline 100 is additionally provided and connected between the side draw outlet pipeline of the ethylene glycol refining unit 50 and the ethylene glycol feed stripping unit 10.

[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 added 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 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.

[0031] Specifically, the ethylene glycol production process uses the reaction of ethylene oxide and water. During the production process, ethylene oxide will continue to react with ethylene glycol to produce other higher homologues such as diethylene glycol, triethylene glycol and heavy ethylene glycol. Ethylene glycol is the main product of the production process, while diethylene glycol, triethylene glycol and heavy ethylene glycol are by-products of the production 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 production 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, transfer pumps, heat exchangers and other equipment and facilities connected thereto. Therefore, the various units mentioned in the embodiment of the present invention refer to the corresponding reaction towers and other equipment, which will not be described in detail here.

[0032] More specifically, the added first pipeline 100 connects the side-line outlet of the ethylene glycol refining unit 50 to the ethylene glycol feed stripping unit 10. This allows the ethylene glycol product initially produced in the ethylene glycol refining unit 50 to be fed into the ethylene oxide and water feedstock in the ethylene glycol feed stripping unit 10. This increases the ethylene glycol content in the feedstock, promoting the reaction between ethylene oxide and ethylene glycol and increasing the production of diethylene glycol, triethylene glycol, and heavy ethylene glycol homologues. In other words, with the same amount of ethylene oxide and water as the feedstock, the production of the ethylene glycol product is reduced, while the production of diethylene glycol, triethylene glycol, and other homologues is increased.

[0033] Furthermore, the outlet pipeline of the refined tower reflux pump in the ethylene glycol refining reflux unit 60 connected to the outlet of the ethylene glycol refining unit 50 is also 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 into the raw materials of ethylene oxide and water in the ethylene glycol feed stripping unit 10, further increasing the content of ethylene glycol in its preparation raw materials, that is, promoting the reaction between ethylene oxide and ethylene glycol, and increasing the formation of diethylene glycol, triethylene glycol and heavy ethylene glycol homologues. That is to say, under the same amount of raw materials of ethylene oxide and water, the yield of ethylene glycol converted into diethylene glycol and triethylene glycol homologues is increased, and the yield of ethylene glycol products is reduced.

[0034] Even further, the side draw outlet pipeline of the diethylene glycol refining unit 80 is connected to the ethylene glycol feed stripping unit 10 by a third pipeline 300, that is, the diethylene glycol product prepared in the diethylene glycol refining unit 80 is transported into the raw materials of ethylene oxide and water in the ethylene glycol feed stripping unit 10, increasing the content of diethylene glycol in its preparation raw materials, that is, promoting the reaction between ethylene oxide and diethylene glycol, and increasing the formation of triethylene glycol and heavy ethylene glycol homologues. That is to say, under the same amount of raw materials of ethylene oxide and water, the yield of diethylene glycol converted into triethylene glycol homologues is increased, and the yield of ethylene glycol products is reduced.

[0035] Please refer to Figure 1 , in an embodiment, a heat exchanger is installed on the side draw 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 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. A cooler is installed on the side draw 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 embodiment of the present invention, please refer to the attached Figure 1 The red line segments in the figure represent the added first pipeline 100, second pipeline 200 and third pipeline 300, which are used to reflux the ethylene glycol and diethylene glycol products in the ethylene glycol production system to the initial reaction tower, that is, the ethylene glycol feed stripping tower. Furthermore, the content of ethylene glycol and diethylene glycol in the ethylene glycol preparation raw materials is increased, promoting the reaction between them and ethylene oxide to produce diethylene glycol and triethylene glycol products. Thus, under the same amount of preparation raw materials, part of the ethylene glycol and diethylene glycol finished products are converted into diethylene glycol and triethylene glycol finished products, 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 span multiple towers and other equipment and 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 the addition of long pipelines is overcome by utilizing the head of the delivery pump and reflux pump, thereby maintaining the effective transportation 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 cooling the diethylene glycol product and facilitating transportation through the third pipeline 300. Please refer to the attached figure. Figure 1 Corresponding pumping equipment is also installed upstream of the cooler pipeline to ensure the transportation of materials and products in the pipeline. Furthermore, compared to the first pipeline 100 and second pipeline 200 added within the ethylene glycol process module, third pipeline 300 has a longer pipeline length. Therefore, corresponding pumping equipment can also be installed on third pipeline 300 to meet the transportation needs of materials and products (not shown in the drawings). Similarly, corresponding pumping equipment can also be installed in first pipeline 100 and second pipeline 200 as needed, but this will not be detailed 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 via material pipelines. Several 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, which in turn is connected to a diethylene glycol refining unit 80 via the ethylene glycol circulation unit 70.

[0039] Specifically, in this embodiment of the present invention, the multi-effect evaporation system 30, formed by connecting multiple-effect evaporation units in series, divides the evaporation process into multiple stages, allowing each stage to utilize the steam generated in the previous stage and reusing the heat in the steam, thereby improving energy efficiency and reducing energy consumption. Furthermore, the cascade operation of the series structure reduces the need for external steam, effectively concentrating the ethylene glycol solution to achieve product purification, and reducing the amount of wastewater discharged.

[0040] More specifically, in the pipeline upstream of the multi-effect evaporation system 30, a reaction occurs 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 through a heat exchanger, so that the raw material liquid output from the ethylene glycol feed stripping unit 10 usually undergoes preheating and reaction heat release 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 in the first effect is relatively high, and the generated steam is used to heat the second effect. The second effect (and subsequent effects) continues to use the steam from the previous effect as the heating source to gradually reduce the moisture 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 is condensed into a liquid and discharged from the system. After multiple evaporations and concentrations, a liquid product with the desired concentration is finally obtained.

[0041] In this way, in the multi-effect evaporation system 30, through the multi-effect series multi-effect evaporation unit, the heat of the steam is utilized efficiently, and the energy consumption is significantly reduced. It can also handle a large amount of liquid, improving the production efficiency. It realizes the reduction of wastewater discharge and other treatment costs.

[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. The separated ethylene glycol component is re-transported through the material pipeline to the multi-effect evaporation system 30, and the separated diethylene glycol component is directly transported to the diethylene glycol refining unit 80 to further purify the products of ethylene glycol and diethylene glycol respectively.

[0043] Please refer to Figure 1 , in an 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. At the ethylene glycol feed stripping unit 10, the outlet position of the third pipeline 300 is higher than the parallel outlet position of the first pipeline 100 and the second pipeline 200. By connecting the first pipeline 100 and the second pipeline 200 that convey 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, it can also control the re-input ethylene glycol material to be at the same position in 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 product is separated by means such as distillation, and by using the different boiling points of ethylene glycol and diethylene glycol, the height position of its re-entry into the ethylene glycol feed stripping unit 10 is controlled, so as to achieve matching with the process at different temperatures and optimize the process of diethylene glycol and triethylene glycol components in the ethylene glycol feed stripping unit 10.

[0044] More specifically, in an embodiment of the present invention, the designed full-load production capacity of the ethylene glycol production system for ethylene glycol MEG product is 127.8 t / h, the production capacity of diethylene glycol DEG product is 10.54 t / h, and the production capacity of triethylene glycol TEG product is 0.555 t / h. When the economic benefit of ethylene glycol MEG product is relatively weak and the economic benefit added value of diethylene glycol DEG product and triethylene glycol TEG product is relatively high, the economic benefit added value of the product can be increased by increasing the production of diethylene glycol DEG product and triethylene glycol TEG product. Thus, after the transformation using the embodiment of the present invention, the production capacity of diethylene glycol DEG product and triethylene glycol TEG product is effectively improved, and the ethylene glycol production system can realize flexible adjustment of the 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 using the improved production capacity of diethylene glycol DEG product and triethylene glycol TEG product, the product benefit of the ethylene glycol production system device is improved.

[0045] In an embodiment of the present invention, the device benefit calculation of a single set of ethylene glycol production system can be referred to: the production of ethylene glycol MEG product is reduced by 1.12 t / h, and the expected reduction in efficiency is 4381.92 yuan / h. The production of diethylene glycol DEG product is increased by about 0.9 t / h, and the estimated profit is about 4305 yuan / h. The production of triethylene glycol TEG product is increased by 0.100 t / h, and the expected profit is about 962.7 yuan / h; the total economic benefit is increased by about 885.78 yuan / h, about 21258.72 yuan is increased every day, and the cumulative monthly benefit of two sets of ethylene glycol devices is increased by 1.27 million.

[0046] In yet another embodiment, reference can be made to the attached Figures 2 to 6, the ethylene glycol reaction unit 20, namely the R-520 reactor, has corresponding undulating changes in its temperature curve with the amounts of ethylene glycol and diethylene glycol products added in the reflux in the first to third pipelines 300. In particular, the temperatures at the elbow end and the front end of the outlet pipe are higher than the original gentle temperature curve, which can reflect the changes in the internal material components. Similarly, regarding the production amount change in the ethylene glycol purification unit 50, namely the T-620 system, with the increase in the amount of ethylene glycol MEG product in the reflux to the ethylene glycol feed stripping unit 10, the bottom discharge of the ethylene glycol dehydration unit 40, namely the T-610 tower, also increases. At the same time, the side stream extraction in the ethylene glycol purification unit 50, that is, the amount of material extracted from the side pipeline leading to the ethylene glycol purification reflux unit 60, also increases. In the outlet pipeline of the diethylene glycol purification unit 80 leading to the third pipeline 300, namely the T-710 side line, with the gradual increase in the amount of ethylene glycol MEG product refluxed to the initial reaction tower, the material extraction amounts in the ethylene glycol circulation unit 70 and the diethylene glycol purification unit 80 increase slowly respectively. In the production amount of the triethylene glycol purification unit 90, namely the T-720 system, similarly, with the gradual increase in the amount of ethylene glycol MEG product in the initial reaction tower, the material extraction amount of the triethylene glycol purification unit 90 also gradually increases. Finally, through the light transmittance detection at different wavelengths, with the gradual increase in the amount of ethylene glycol MEG product refluxed to the initial reaction tower, there is no obvious impact on the light 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, an ethylene glycol production system for increasing the production of diethylene glycol and triethylene glycol provided by the present invention realizes adjusting the production amount of ethylene glycol and converting it into diethylene glycol DEG products and triethylene glycol TEG products by transforming the ethylene glycol production system device. Under different market benefits of ethylene glycol, diethylene glycol, or triethylene glycol, it can improve the comprehensive benefit of the products; and has small changes in the pipeline structure of the existing production system device, high conversion rates of diethylene glycol DEG products and triethylene glycol TEG products, reduces the production amount of ethylene glycol MEG products, and increases the production amounts of diethylene glycol DEG products and triethylene glycol TEG products.

[0048] The above embodiments are only illustrative of the principles and effects of the present invention, and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should 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, It includes 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 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 additionally provided and connected between the side draw outlet pipeline of the ethylene glycol refining unit (50) and the ethylene glycol feed stripping unit (10). The ethylene glycol process module further includes an ethylene glycol dehydration unit (40). The ethylene glycol dehydration unit (40) is located on the upstream pipeline of the ethylene glycol refining unit (50), and a second pipeline (200) is additionally provided and connected between the outlet of the reflux pump of the refining tower of the ethylene glycol refining unit (50) and the ethylene glycol feed stripping unit (10). A third pipeline (300) is additionally provided and connected between the side draw outlet pipeline of the diethylene glycol refining unit (80) and the ethylene glycol feed stripping unit (10); 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 parallel outlet position of the first pipeline (100) and the second pipeline (200).

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

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

4. The production system according to claim 1, characterized in that, The top outlet of the ethylene glycol refining unit (50) is further 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). The inlet of the second pipeline (200) is connected to the outlet pipeline of the reflux pump.

5. The production system according to claim 4, wherein The outlet of the ethylene glycol refining unit (50) is further connected to an ethylene glycol circulation unit (70). The ethylene glycol refining unit (50) is connected to the diethylene glycol refining unit (80) through the ethylene glycol circulation unit (70).

6. The production system according to claim 1, characterized in that, A cooler is installed on the side draw outlet pipeline of the diethylene glycol refining unit (80). The inlet of the third pipeline (300) is connected to the outlet pipeline of the cooler.

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