Evaporator and separation method using the same

Abstract

An evaporator according to one embodiment of the present application includes a tower in which a plurality of packings are stacked, an upper inlet, a middle inlet, and a lower inlet provided at an upper portion, a middle portion, and a lower portion of the tower, respectively, an upper outlet and a lower outlet provided at the upper portion and the lower portion of the tower, respectively, a pump connected to the lower outlet, and a heater connected between the pump and the middle inlet.

Description

Technical Field

[0001] Cross-reference to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2021-0034018, filed with the Korean Intellectual Property Office on March 16, 2021, the entire contents of which are incorporated herein by reference.

[0003] This disclosure relates to an evaporator and a separation method using the evaporator. Background Technology

[0004] Typically, to produce compounds, multiple substances are mixed and subjected to multiple reactions.

[0005] In multiple reaction processes, unwanted substances are generated, which reduces production efficiency.

[0006] Therefore, unwanted reactants are removed during the intermediate process. In a gas-phase reactor, a single evaporator or a combination of a distillation column and a single evaporator is used to separate and remove some of the liquid-phase reactants containing the compounds so that they can participate in the reaction.

[0007] A single evaporator requires less heat but has a lower efficiency in removing heavy substances, around 10%. On the other hand, a combination of a distillation column and a single evaporator has a high efficiency in removing heavy substances, exceeding 90%, but requires a large amount of heat. Summary of the Invention

[0008] Technical issues

[0009] This disclosure attempts to provide an evaporator that can improve the efficiency of removing heavy substances while reducing the amount of heat used, as well as a separation method using the evaporator.

[0010] Technical solution

[0011] An exemplary embodiment of the present invention provides an evaporator, comprising: a tower in which a plurality of packing materials are stacked; an upper inlet, a middle inlet, and a lower inlet respectively disposed in the upper, middle, and lower portions of the tower; an upper outlet and a lower outlet respectively disposed in the upper and lower portions of the tower; a pump connected to the lower outlet; and a heater connected between the pump and the middle inlet.

[0012] The evaporator may also include a first supply unit and a second supply unit for supplying the target material to the tower, wherein the first supply unit is connected to the upper inlet and the second supply unit is connected to the lower inlet.

[0013] The target substance to be separated can be stored in the first supply unit, and the second supply unit may include a first storage tank for storing the target substance and a second storage tank for storing the gas to be supplied together with the target substance.

[0014] The evaporator may further include: a first heater located between the first feed unit and the tower; and a second heater located between the second feed unit and the tower.

[0015] The tower may include: a first tower, to which the target material is supplied from a first supply unit through an upper inlet; and a second tower located below the first tower.

[0016] The first and second towers may include multiple structured packings, and the number of packing stages in the first tower and the number of packing stages in the second tower may be different from each other.

[0017] The material discharged through the lower outlet is then fed back to the tower through the middle inlet after passing through a pump and heater.

[0018] Another exemplary embodiment of the present invention provides a separation method using the above-described evaporator, the separation method comprising: injecting a target substance into the upper inlet and the lower inlet of the evaporator; and injecting a substance discharged from the lower outlet after passing through the tower into the middle inlet via a pump and a heater, wherein when the target substance is injected into the upper inlet and the lower inlet, gas is injected together with the target substance into the lower inlet.

[0019] Target substances may include 2-EHEL and heavy substances.

[0020] The gas may include at least one of hydrogen, methane, carbon dioxide, and carbon monoxide.

[0021] The heater between the first supply unit and the tower can heat the material to be discharged to a temperature of 70°C to 122°C, and the heater between the second supply unit and the tower can heat the material to be discharged to a temperature of 105°C to 115°C.

[0022] Beneficial effects

[0023] By using an evaporator according to an exemplary embodiment of the present disclosure, the efficiency of separating 2-EHEL and removing heavy substances can be improved. Attached Figure Description

[0024] Figure 1 This is a schematic construction diagram of an evaporator according to an exemplary embodiment of the present disclosure.

[0025] Figure 2 It is a graph showing the heat (load) and heavy material removal rate based on the fill height in an evaporator according to an exemplary embodiment of the present disclosure.

[0026] Figure 3 This is a graph showing the heat, heavy material removal rate, and maximum overflow % as a function of the ratio of the number of circulating feed stages to the total number of stages, when the target material is supplied through the middle inlet according to an exemplary embodiment of the present disclosure.

[0027] Figure 4 This is a graph showing the heat, heavy material removal rate, and maximum overflow % as the ratio of the amount of 2-EHEL supplied through the upper inlet to the amount of 2-EHEL injected through the lower inlet varies according to an exemplary embodiment of this disclosure.

[0028] Figure 5 This is a graph showing the heat, heavy material removal rate, and maximum overflow % as the temperature supplied to the 2-EHEL through the upper inlet changes, according to an exemplary embodiment of the present disclosure.

[0029] Figure 6 This is a graph showing the heat, heavy material removal rate, and maximum overflow % as the temperature of the 2-EHEL supplied through the inlet changes, according to an exemplary embodiment of the present disclosure. Detailed Implementation

[0030] Exemplary embodiments of this disclosure will now be described in detail with reference to the accompanying drawings, enabling those skilled in the art to readily implement this disclosure. This disclosure may be implemented in various different forms and is not limited to the exemplary embodiments described herein.

[0031] In the following, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0032] Figure 1 This is a schematic construction diagram of an evaporator according to an exemplary embodiment of the present disclosure.

[0033] like Figure 1 As shown, an evaporator according to an exemplary embodiment of the present disclosure includes a tower 100, and a pump 201 and a heater 202 connected to the tower 100.

[0034] Tower 100 may be configured as a stripping tower to facilitate contact with the liquid, and multiple trays may be arranged in tower 100, or tower 100 may include random packing or structured packing. The internal structure of the tower is well known, and therefore its detailed description will be omitted.

[0035] Tower 100 includes a first tower 11 located at the top of tower 100 and a second tower 12 located below the first tower 11. For example, each of the first tower 11 and the second tower 12 may include 10 stages of packing.

[0036] The target substances to be separated, such as 2-ethyl-2-hexenal (2-EHEL) to be evaporated upwards and heavy substances to be separated downwards, can be injected into column 100. Heavy substances may include substances with boiling points higher than 2-EHEL, such as substances containing more than 9 carbons (C) and substances containing sulfur (S).

[0037] Tower 100 is formed having an upper entrance 21, a lower entrance 23, and a middle entrance 25. The upper entrance 21 may be located above the first tower 11, the lower entrance 23 may be located below the second tower 12, and the middle entrance 25 may be located between the first tower 11 and the second tower 12.

[0038] The target substance can be stored in liquid form in the first storage tank 101 and injected through the upper inlet 21 and lower inlet 23 of the tower 100.

[0039] The first storage tank 101 for supplying the target substance and the second storage tank 102 for injecting gas can be connected to the tower 100.

[0040] The target material stored in the first storage tank 101 can be injected into the upper inlet 21 (see dashed line (1)), and the gas can be injected into the lower inlet 23 together with the target material (see dashed line (2)).

[0041] Some of the target substances injected through the upper inlet 21 evaporate through mass exchange and heat exchange as they pass through the first tower 11 and the second tower 12, and are discharged as gas through the upper outlet 27. The remaining target substances that are not discharged as gas, some 2-EHEL substances and substances with boiling points higher than 2-EHEL, are discharged to the outside through the lower outlet 29 (see dashed line (3)).

[0042] The heaters can be connected to the upper inlet and the lower inlet. The first heater 31 connected to the upper inlet can heat the injected material to a temperature of 70°C to 122°C, and the second heater 32 connected to the lower inlet can heat the injected material to a temperature of 105°C to 115°C.

[0043] Some of the target material supplied through the lower inlet 23 can be evaporated and discharged along with the injected gas through the upper outlet 27. Therefore, the gas injected along with the target material through the lower inlet 23 can be a light gas, such as hydrogen, methane, butane, carbon monoxide, or carbon dioxide, to facilitate the upward evaporation of the target material. The target material supplied through the lower inlet 23 evaporates along with the injected gas and moves upward, being discharged through the upper outlet 27, while the target material not discharged as a gas, some 2-EHEL substances, and substances with boiling points above 2-EHEL are discharged from the column through the lower outlet 29.

[0044] Meanwhile, the target substances supplied through the upper inlet 21 that have not been evaporated and discharged, as well as the target substances supplied through the lower inlet 23 that have not been evaporated and discharged, some 2-EHEL substances and substances with boiling points higher than 2-EHEL, are discharged from the tower 100 (see dashed line (3)).

[0045] Some of the target material discharged from tower 100 is discharged outside the tower via pump 201 (see dashed line (5)), while other target materials discharged from tower 100 are supplied to heater 202 (see dashed line (4)). The target material passing through heater 202 is injected into the middle inlet 25 of tower 100. At this time, the material discharged outside the tower and the material injected back into tower 100 through the middle inlet 25 have the same composition and can be supplied separately according to the flow rate ratio.

[0046] The middle inlet 25 is located between the first tower 11 and the second tower 12. The target material injected into the middle inlet 25 is supplied to the second tower 12.

[0047] The target substance injected through the central inlet 25 is supplied in a heated state via heater 202. At this time, the target substance injected through the central inlet can be injected after being heated to a temperature of 122°C to 140°C, so as to provide heat to the substance inside the second column 12 and increase the temperature of the substance. Therefore, the substance in the second column, which is supplied with heat, can evaporate more easily and pass through the first column 11 while evaporating at a relatively elevated temperature.

[0048] The target material injected through the middle inlet exchanges mass and heat with the target material supplied to the first tower 11 through the upper inlet 21, making it easier to induce the evaporation of the target material supplied through the upper inlet 21.

[0049] As described above, in the exemplary embodiments of this disclosure, by dividing the interior of tower 100 into a first tower 11 and a second tower 12, then heating the target substance discharged to the outside and injecting the heated target substance between the first tower 11 and the second tower 12, the target substance can be separated from each other more quickly and effectively.

[0050] Figure 2 This is a graph showing the energy consumption (load) and heavy material removal rate based on the fill height in an evaporator according to an exemplary embodiment of the present disclosure.

[0051] exist Figure 2 In this context, regarding the packing material stacked in the tower, the theoretical height of the equal-volume packing (HETP) is 0.5m, the packing diameter is 1.6m, and the ratio of the number of recirculating feed stages to the total number of stages is 0.7. This ratio represents the ratio of the first tower to the total number of stages. A ratio of 0.7 indicates that the number of stages in the first tower differs from the number of stages in the second tower. If the total number of stages is 20 and the ratio is 0.7, it means the first tower has 14 stages and the second tower has 6 stages.

[0052] The target substance is discharged through the lower outlet at a flow rate of 390 kg / hr. The target substance supplied through the upper inlet includes 2-EHEL, heavy substances, and other substances. At this time, the ratio of the amount of 2-EHEL supplied through the upper inlet to the amount of 2-EHEL injected through the lower inlet is 0.42.

[0053] See Figure 2 It can be confirmed that as the height increases from 5m to 10m, the heat (load) decreases while the removal rate of heavy materials increases. In other words, it can be seen that as the height increases, the heat decreases, and therefore the energy consumption decreases.

[0054] Figure 3 This is a graph showing the heat, heavy material removal rate, and maximum overflow % as a function of the ratio of the number of circulating feed stages to the total number of stages, according to an exemplary embodiment of the present disclosure, when the target material is supplied through the middle inlet.

[0055] exist Figure 3 Regarding the packing material stacked in the tower, the HETP packing is 0.5m thick, the packing diameter is 1.6m, and the packing height is 5m. Additionally, the target material is supplied to the lower inlet at a flow rate of 390 kg / hr, and the ratio of the amount of 2-EHEL supplied through the upper inlet to the amount of 2-EHEL injected through the lower inlet is 0.42.

[0056] The ratio of the number of recycle feed stages to the total number of stages indicates the location of the unit supplying the target material through the middle inlet. The closer the ratio is to 0, the closer the unit location is to the top of the column, while the closer the ratio is to 1, the closer the unit location is to the bottom of the column.

[0057] See Figure 3 As the ratio of the number of recirculating feed stages to the total number of stages increases, i.e., the unit location is closer to the bottom of the column, the heat (load) decreases, while the removal rate of heavy materials increases. As a result, when the ratio is 1, a removal efficiency of over 90% is achieved. Furthermore, it has been confirmed that when the ratio of the inlet stage to the total number of stages increases from 0.9 to 1, the maximum overflow percentage remains at approximately 80% and increases to almost 90%.

[0058] Maximum overflow % is an indicator used when operating the column and is a value calculated based on the flow rates of the gas and liquid present inside the column and the characteristics of the packing or trays inside the column. Since separation efficiency may decrease when the maximum overflow % exceeds 80%, the column is operated with a maximum overflow % of 80% or less. Therefore, in an exemplary embodiment of this disclosure, the middle inlet can be positioned such that the ratio of the number of recirculated feed stages to the total number of stages is 0.8 or less. To obtain a heavy material removal rate of 90% or more, the ratio of the number of recirculated feed stages to the total number of stages can be 0.6 or more. That is, according to an exemplary embodiment of this disclosure, the ratio of the number of recirculated feed stages to the total number of stages can be 0.6 or more and 0.8 or less.

[0059] Figure 4 This is a graph showing the heat (load), heavy material removal rate, and maximum overflow % as the ratio of the amount of 2-EHEL supplied through the upper inlet to the amount of 2-EHEL injected through the lower inlet varies according to an exemplary embodiment of the present disclosure.

[0060] exist Figure 4 Regarding the packing material stacked in the tower, the HETP packing is 0.5m, the packing diameter is 1.6m, and the packing height is 5m. The ratio of the number of circulating feed stages to the total number of stages is 0.7.

[0061] See Figure 4 It can be seen that when the ratio of the amount of 2-EHEL supplied through the upper inlet to the amount of 2-EHEL injected through the lower inlet increases from 0.2 to 0.4, the heat decreases rapidly, but thereafter the heat decreases slowly.

[0062] Furthermore, when the ratio of the amount of 2-EHEL supplied through the upper inlet to the amount of 2-EHEL injected through the lower inlet increased from 0.2 to 0.4, the heavy mass removal rate increased rapidly, but thereafter, despite the increase in the ratio, the heavy mass removal rate remained at around 95%.

[0063] Furthermore, it was confirmed that the maximum overflow percentage increases steadily with the increase of this ratio, and the maximum overflow percentage exceeds 80% when the ratio of the 2-EHEL supply exceeds 0.6. Since the separation efficiency decreases when the maximum overflow percentage exceeds 80%, the ratio of the 2-EHEL supply according to the exemplary embodiment of this disclosure is preferably 0.4 to 0.6.

[0064] Figure 5 This is a graph showing the heat, heavy material removal rate, and maximum overflow % as the temperature supplied to the 2-EHEL through the upper inlet changes, according to an exemplary embodiment of the present disclosure.

[0065] exist Figure 5 In this tower, the HETP packing depth is 0.5m, the packing diameter is 1.6m, and the packing height is 5m. Additionally, the target material is supplied to the lower inlet at a flow rate of 390 kg / hr. The ratio of the amount of 2-EHEL supplied through the upper inlet to the amount of 2-EHEL injected through the lower inlet is 0.42. The ratio of the number of circulating feed stages to the total number of stages is 0.7.

[0066] See Figure 5It can be seen that as the temperature supplied to the 2-EHEL through the upper inlet increases, the heat continuously increases, while the maximum overflow percentage slowly decreases. It can also be seen that when the supply temperature is above or equal to 120℃, the maximum overflow percentage becomes below 80%. Furthermore, it can be seen that the removal rate of heavy materials remains consistently between 90% and 95%.

[0067] Therefore, the 2-EHEL supplied through the upper inlet is preferably supplied at a temperature above 120°C, so that the maximum overflow percentage is below 80%.

[0068] Figure 6 This is a graph showing the heat, heavy material removal rate, and maximum overflow % as the temperature of the 2-EHEL supplied through the inlet changes, according to an exemplary embodiment of the present disclosure.

[0069] exist Figure 6 In this tower, the HETP packing depth is 0.5m, the packing diameter is 1.6m, and the packing height is 5m. Additionally, the target material is supplied to the lower inlet at a flow rate of 390 kg / hr. The ratio of the amount of 2-EHEL supplied through the upper inlet to the amount of 2-EHEL injected through the lower inlet is 0.42. The ratio of the number of circulating feed stages to the total number of stages is 0.7.

[0070] See Figure 6 It can be seen that as the temperature supplied to 2-EHEL through the middle inlet increases, the heat and maximum overflow percentage decrease, while the removal rate of heavy materials remains at 90%.

[0071] Because the temperature rise when 2-EHEL is supplied through the middle inlet greatly reduces heat and maximum overflow, while maintaining the heavy removal rate above 90%, the tower can be operated at a temperature of 135°C or higher when 2-EHEL is supplied through the middle inlet.

[0072] As described above, by using an evaporator according to an exemplary embodiment of the present disclosure, a heavy material removal rate of 92.8% was achieved at 3.6 Gcal / hr (which is the same as the heat in a conventional evaporator), which is an improvement compared to the 16.4% of a conventional evaporator.

[0073] Furthermore, in order to achieve a heavy substance removal rate of over 90%, conventional distillation columns require 5.5 Gcal / hr or more of heat, while the evaporator according to an exemplary embodiment of the present disclosure can achieve a heavy substance removal rate of over 90% at 3.6 Gcal / hr.

[0074] While preferred exemplary embodiments of the present disclosure have been described above, the present disclosure is not limited thereto, and various modifications can be made within the scope of the claims, the detailed description of the invention, and the accompanying drawings. It is self-evident that such modifications also fall within the scope of this disclosure.

Claims

1. An evaporator, comprising: A tower containing multiple stacked packing materials; The upper, middle, and lower inlets are respectively located at the upper, middle, and lower parts of the tower; The upper and lower outlets are respectively located at the upper and lower parts of the tower; A pump connected to the lower outlet; as well as A heater connected between the pump and the inlet, and The target substance is supplied to the first and second supply units of the tower. The first supply unit is connected to the upper inlet, and The second supply unit is connected to the lower inlet. The gas is injected together with the target substance into the lower inlet.

2. The evaporator according to claim 1, wherein... The first supply unit includes a first storage tank for storing the target material to be separated, and The second supply unit includes a second storage tank for storing the gas to be supplied together with the target substance.

3. The evaporator according to claim 2, further comprising: A first heater is located between the first supply unit and the tower; as well as A second heater is located between the second supply unit and the tower.

4. The evaporator according to claim 1, wherein, The tower includes: A first tower, wherein the target material is supplied from the first supply unit to the first tower through the upper inlet; and The second tower is located below the first tower.

5. The evaporator according to claim 4, wherein The first and second towers each contain multiple structured packing materials. The number of packing stages in the first tower is different from that in the second tower.

6. The evaporator according to claim 1, wherein, The material discharged through the lower outlet is fed into the tower through the middle inlet after passing through the pump and the heater.

7. A separation method using an evaporator according to any one of claims 1 to 6, the separation method comprising: The target substance is injected into the upper and lower inlets of the evaporator; as well as The material discharged from the lower outlet after passing through the tower is injected into the middle inlet via the pump and the heater. When the target substance is injected into the upper inlet and the lower inlet... The gas is injected together with the target substance into the lower inlet.

8. The separation method according to claim 7, wherein, The target substances include 2-EHEL and heavy substances.

9. The separation method according to claim 7, wherein, The gas includes at least one of hydrogen, methane, carbon dioxide, and carbon monoxide.

10. The separation method according to claim 7, wherein, The heater between the first supply unit and the tower heats the substance to be discharged to a temperature of 70°C to 122°C, and The heater between the second supply unit and the tower heats the material to be discharged to a temperature of 105°C to 115°C.

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