Acetate production energy-saving device

Abstract

The utility model provides an acetic ester production energy-saving device, which comprises an esterification tower, the upper end of the esterification tower is provided with an esterification product outlet, the esterification product outlet is provided with an esterification product pipeline, and the side surface of the upper end of the esterification tower is provided with a reflux product inlet; a discharge port is formed in the bottom of the rectifying tower, and a discharge pipe is arranged on the discharge port; the first heat exchanger is arranged at the joint of the esterification product pipeline and the discharging pipe, a first esterification return pipe is further arranged on the first heat exchanger, and the esterification product pipeline is communicated with the first esterification return pipe; the esterification tower is thermally coupled with the finished product rectifying tower and the recovery tower, steam does not need to be additionally input into the finished product rectifying tower and the recovery tower only by injecting steam into the esterification tower at a time, the whole device only uses steam in the esterification tower, and steam consumption is greatly reduced.

Description

Technical Field

[0001] This application relates to an acetate production apparatus, and more particularly to an energy-saving acetate production apparatus. Background Technology

[0002] Currently, traditional acetate production equipment requires multiple steam injections during operation to ensure sufficient temperature for each tower (such as the esterification tower, product distillation tower, and recovery tower) at different production stages, thereby completing operations such as esterification, product distillation, and solvent recovery. However, this multi-point steam injection method presents the following technical problems:

[0003] In traditional processes, each tower requires independent steam injection, resulting in low steam resource utilization and significant heat loss due to the independent steam supply to multiple towers. Furthermore, the inability to effectively utilize steam in stages leads to high overall steam consumption. Multi-point steam injection not only requires additional steam supply but also increases equipment maintenance and operating costs. Simultaneously, the large-volume steam supply necessitates additional fuel or electricity, further increasing production costs. The frequent steam injection required in traditional processes is complex and labor-intensive. Moreover, the high-temperature, high-pressure steam is prone to leakage or malfunction during pipeline and equipment operation, posing significant safety hazards. Independent steam injection for each tower can easily lead to insufficient heat transfer between equipment, inadequate heat energy utilization, and reduced equipment operating efficiency. Utility Model Content

[0004] This application provides an energy-saving device for acetate production to solve the problems existing in related technologies. The technical solution is as follows:

[0005] This application provides an energy-saving device for acetate production, comprising:

[0006] An esterification tower, wherein the upper end of the esterification tower has an esterification product outlet, an esterification product pipeline is provided on the esterification product outlet, and the upper side of the esterification tower has a reflux product inlet.

[0007] A distillation column, wherein the bottom of the distillation column has a discharge port and a discharge pipe is provided on the discharge port;

[0008] A first heat exchanger is provided at the connection between the esterification product pipeline and the discharge pipe. A first esterification reflux pipe is also provided on the first heat exchanger. The esterification product pipeline is connected to the first esterification reflux pipe.

[0009] The recovery tower has a water recovery outlet at its bottom and a recovery tower discharge pipe on the water recovery outlet. A second heat exchanger is provided at the connection between the recovery tower discharge pipe and the esterification product pipeline. A second esterification reflux pipe is provided at one end of the second heat exchanger. The second esterification reflux pipe is connected to the esterification product pipeline, and the first esterification reflux pipe is connected to the second esterification reflux pipe.

[0010] In one implementation, it further includes:

[0011] A condenser phase separator is installed on the second esterification reflux pipe. The condenser phase separator is connected to the esterification tower through a first condenser pipe, to the distillation tower through a second condenser pipe, and to the recovery tower through a third condenser pipe.

[0012] In one implementation, it further includes:

[0013] An esterification reboiler is provided outside the esterification tower. One end of the esterification reboiler is equipped with a steam pipe, and the other end is connected to the esterification tower. External steam is heated by the esterification reboiler and then transported into the esterification tower.

[0014] In one implementation, it further includes:

[0015] A first vacuum pump is installed on the distillation column.

[0016] The top of the recovery tower has a head ester outlet, and a recovery pipe is connected to the head ester outlet.

[0017] The recovery pipe is connected to a waste heat recovery pipe, which is connected to the recovery tower.

[0018] In one implementation, it further includes:

[0019] A condensing heat exchanger is disposed at the connection between the recovery pipe and the waste heat recovery pipe.

[0020] In one implementation, it further includes:

[0021] A second vacuum pump is installed on the recovery tower.

[0022] The advantages or beneficial effects of the above technical solutions include at least the following:

[0023] By thermally coupling the products of the esterification tower with the products of the finished product distillation tower and the recovery tower, and exchanging heat between the products of the finished product distillation tower and the recovery tower and the products of the esterification tower respectively, it is possible to achieve a situation where only one injection of steam is needed into the esterification tower, and no additional steam input is required for the finished product distillation tower and the recovery tower. Only the esterification tower uses steam in the entire unit, which significantly reduces steam consumption from 1.4 t / h to 0.8-1.0 t / h, greatly saving the amount of steam required for the entire unit, and thus achieving energy saving in the production process.

[0024] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of this application will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0025] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0026] Figure 1 This is a schematic diagram of the structure of this utility model;

[0027] 100. Acetate production equipment;

[0028] 110. Esterification tower; 111. Reflux product inlet; 112. Esterification product outlet; 113. Esterification reboiler; 114. First heat exchanger; 115. Steam pipe; 116. Esterification product pipeline;

[0029] 120. Distillation column; 121. Condenser / phase separator; 122. Discharge port; 123. First condenser; 124. First vacuum pump; 125. Second condenser; 126. Discharge pipe; 127. Third condenser; 128. First esterification reflux pipe;

[0030] 130. Recovery tower; 131. Water recovery outlet; 132. Recovery pipe; 133. Second vacuum pump; 134. Condensation heat exchanger; 135. Second heat exchanger; 136. Recovery tower discharge pipe; 137. Head ester outlet; 138. Waste heat recovery pipe; 139. Second esterification reflux pipe. Detailed Implementation

[0031] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this application. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0032] Example 1

[0033] like Figure 1 As shown, the acetate production apparatus 100 may include:

[0034] Esterification tower 110, the upper end of the esterification tower 110 has an esterification product outlet 112, the esterification product outlet 112 is provided with an esterification product pipe 116, and the upper side of the esterification tower 110 has a reflux product inlet 111.

[0035] A distillation column 120 has a discharge port 122 at its bottom, and a discharge pipe 126 is provided on the discharge port 122.

[0036] The first heat exchanger 114 is located at the connection between the esterification product pipeline 116 and the discharge pipe 126. The first heat exchanger 114 is also provided with a first esterification reflux pipe 128. The esterification product pipeline 116 is connected to the first esterification reflux pipe 128.

[0037] Specifically, after the esterification product of the distillation column 120 is discharged through the discharge pipe 126, it exchanges heat with the product in the esterification product pipeline 116 through the first heat exchanger 114. The product in the esterification product pipeline 116 then changes from a vaporized state to a liquefied state and enters the first esterification reflux pipe 128. Since the first esterification reflux pipe 128 is connected to the second esterification reflux pipe 139, the liquefied product passes through the second esterification reflux pipe 139 and the condenser / phase separator 121, where it undergoes condensation and phase separation to produce an aqueous phase and a third phase. A first oil phase and a second oil phase; wherein, the aqueous phase is refluxed to the recovery tower 130 through the third condenser 127, the first oil phase is refluxed to the esterification tower 110 from the reflux product inlet 111 at the top of the esterification tower 110 through the first condenser 123, the second oil phase enters the distillation tower 120 from the middle through the second condenser 125, and the esterification product in the discharge pipe 126 is refluxed to the distillation tower 120 at the bottom of the distillation tower 120 as a heat source for the distillation tower 120.

[0038] In this embodiment, the first heat exchanger 114 enables heat exchange between the products of the distillation column 120 and the products of the esterification column 110, thereby achieving energy-saving effects.

[0039] like Figure 1 As shown, in one embodiment,

[0040] A recovery tower 130 has a water recovery outlet 131 at its bottom. A recovery tower discharge pipe 136 is provided on the water recovery outlet 131. A second heat exchanger 135 is provided at the connection between the recovery tower discharge pipe 136 and the esterification product pipeline 116. A second esterification reflux pipe 139 is provided at one end of the second heat exchanger 135. The second esterification reflux pipe 139 is connected to the esterification product pipeline 116. The first esterification reflux pipe 128 is connected to the second esterification reflux pipe 139.

[0041] In one implementation, it further includes:

[0042] A condenser phase separator 121 is installed on the second esterification reflux pipe 139. The condenser phase separator 121 is connected to the esterification tower 110 through the first condenser pipe 123, the condenser phase separator 121 is connected to the distillation tower 120 through the second condenser pipe 125, and the condenser phase separator 121 is connected to the recovery tower 130 through the third condenser pipe 127.

[0043] Because the product in the esterification product pipeline 116 is thermally coupled with the esterification product in the discharge pipe 126, the product in the esterification product pipeline 116 still retains some heat. Therefore, the product of the recovery tower 130 can be discharged through the recovery tower discharge pipe 136, and then pass through the second heat exchanger 135 to exchange heat with the product in the esterification product pipeline 116. After the heat exchange, the vaporized product produced at the esterification product outlet 112 is converted into liquefied product and enters the second esterification reflux pipe 139. After passing through the condenser phase separator 121, it is condensed and phase-separated. An aqueous phase and a first and second oil phase are generated. The aqueous phase is refluxed to the recovery tower 130 through the third condenser 127. The first oil phase is refluxed to the esterification tower 110 from the reflux product inlet 111 at the top of the esterification tower 110 through the first condenser 123. The second oil phase enters the distillation tower 120 from the middle through the second condenser 125. The product discharged through the recovery tower outlet pipe 136 is refluxed to the recovery tower 130 after heat exchange, serving as the heat source for the recovery tower 130.

[0044] In this embodiment, the vaporized product temperature at the esterification product outlet 112 at the top of the esterification tower 110 is 105℃-110℃, and the pressure is controlled at 0.1-0.25MPa(G). This allows the product at 75-75℃ in the finished product distillation tower 120 and the water at 100℃ in the recovery tower 130 to be thermally coupled with the product of the esterification tower 110. The heat-exchanged products from the finished product distillation tower 120 and the recovery tower 130 are then refluxed back to the distillation tower 120 and the recovery tower 130, respectively, as heat sources. This eliminates the need for additional steam in the finished product distillation tower 120 and the recovery tower 130; only the esterification tower 110 uses steam, resulting in a significant reduction in steam consumption. The vaporized product from the esterification product outlet 112 after heat exchange is converted into a liquefied product and enters the first esterification reflux pipe 128. The first esterification reflux pipe 128 is connected to the second esterification reflux pipe 139. After passing through the second esterification reflux pipe 139 and the condenser phase separator 121, an aqueous phase and a first part of the oil phase and a second part of the oil phase are generated by condensation phase separation. Among them, the aqueous phase is refluxed to the recovery tower 130 through the third condenser pipe 127, the first part of the oil phase is refluxed to the esterification tower 110 from the reflux product inlet 111 at the top of the esterification tower 110 through the first condenser pipe 123, and the second part of the oil phase enters the distillation tower 120 from the middle of the distillation tower 120 through the second condenser pipe 125.

[0045] By thermally coupling the esterification tower 110 with the product distillation tower 120 and the recovery tower 130, steam only needs to be injected into the esterification tower 110 once, so that the product distillation tower 120 and the recovery tower 130 do not need to be fed in with additional steam. Only the esterification tower 110 uses steam in the entire unit, which greatly reduces steam consumption and saves a lot of steam required for the entire unit, thereby achieving energy saving in the production process.

[0046] In this embodiment, the outlet 122 at the bottom of the distillation column 120 is connected to the outlet pipe 126, and the product of the outlet pipe 126 is returned to the distillation column 120 after heat exchange.

[0047] like Figure 1 As shown, it also includes:

[0048] An esterification reboiler 113 is provided outside the esterification tower 110. One end of the esterification reboiler 113 is provided with a steam pipe 115, and the other end is connected to the esterification tower 110. External steam is heated by the esterification reboiler 113 and then transported into the esterification tower 110.

[0049] Steam heats the material through the esterification reboiler 113 and is then transported to the esterification tower 110, thereby raising the temperature of the steam and vaporizing it to reach the required steam temperature for the esterification tower 110.

[0050] In this embodiment, it also includes:

[0051] A first vacuum pump 124 is installed on the distillation column 120.

[0052] In this embodiment, the gas pressure inside the distillation column 120 is controlled by the first vacuum pump 124, so that the distillation column 120 is in a state of normal pressure or negative pressure (-0.02 to -0.05 MPa), thereby ensuring the vacuum environment inside the distillation column 120, so as to lower the boiling point inside the distillation column 120 and reduce the loss of steam heat.

[0053] The top of the recovery tower 130 has a head ester outlet 137, and a recovery pipe 132 is connected to the head ester outlet 137.

[0054] The recovery pipe 132 is connected to a waste heat recovery pipe 138, which is connected to the recovery tower 130.

[0055] like Figure 1 As shown, it also includes:

[0056] A condensing heat exchanger 134 is disposed at the connection between the recovery pipe 132 and the waste heat recovery pipe 138.

[0057] In this embodiment, the heat exchanged material in the recovery pipe 132 is partially transported back to the recovery tower 130 through the waste heat recovery pipe 138 via the condensing heat exchanger 134, while the condensed material is discharged to the outside through the recovery pipe 132, thereby reducing heat consumption.

[0058] Also includes:

[0059] The second vacuum pump 133 is installed on the recovery tower 130;

[0060] In this embodiment, the gas pressure inside the recovery tower 130 is controlled by the second vacuum pump 133, so that the recovery tower 130 is in a state of normal pressure or negative pressure (-0.02 to -0.05 MPa), thereby ensuring the vacuum environment inside the recovery tower 130, so as to lower the boiling point inside the recovery tower 130 and reduce the loss of steam heat.

[0061] By using the product at the top of the esterification tower 110 as a heat source for the product distillation tower 120 and the recovery tower 130, the product distillation tower 120 and the recovery tower 130 do not need to be reheated. Only the esterification reboiler 113 needs to be injected with steam, which greatly reduces steam consumption.

[0062] The functions of each module in each device of this utility model embodiment can be found in the corresponding description in the above method, and will not be repeated here.

[0063] Comparative Example 1

[0064] The difference between this comparative example and Example 1 is that the esterification products produced by the esterification product pipeline 116 at the top of the esterification tower 110 are not thermally coupled to the discharge pipe 126 and the discharge pipe 136 of the recovery tower. That is, the products of the esterification product pipeline 116 at the top of the esterification tower 110 directly enter the distillation tower 120. Both the distillation tower 120 and the recovery tower 130 use external steam, and the other structures are the same.

[0065] Test case

[0066] Steam consumption was tested on the acetate production apparatus of Example 1 and Test Example 1.

[0067] The test results are shown in Table 1.

[0068] Table 1. Steam consumption test results of the acetate production unit in Example 1 and Comparative Example 1

[0069] Example 1 Comparative Example 1 Steam consumption (t / t) 0.8-1.0 1.4

[0070] As can be seen, in Example 1, since only the esterification tower uses steam, the steam consumption is greatly reduced, which saves a lot of steam required for the entire device.

[0071] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0072] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0073] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this application, and these should all be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An energy-saving device for acetate production, characterized in that, include: An esterification tower, wherein the upper end of the esterification tower has an esterification product outlet, an esterification product pipeline is provided on the esterification product outlet, and the upper side of the esterification tower has a reflux product inlet. A distillation column, wherein the bottom of the distillation column has a discharge port and a discharge pipe is provided on the discharge port; A first heat exchanger is provided at the connection between the esterification product pipeline and the discharge pipe. A first esterification reflux pipe is also provided on the first heat exchanger. The esterification product pipeline is connected to the first esterification reflux pipe. The recovery tower has a water recovery outlet at its bottom and a recovery tower discharge pipe on the water recovery outlet. A second heat exchanger is provided at the connection between the recovery tower discharge pipe and the esterification product pipeline. A second esterification reflux pipe is provided at one end of the second heat exchanger and is connected to the esterification product pipeline. The first esterification reflux pipe is connected to the second esterification reflux pipe.

2. The energy-saving device for acetate production according to claim 1, characterized in that, Also includes: A condenser phase separator is installed on the second esterification reflux pipe. The condenser phase separator is connected to the esterification tower through a first condenser pipe, to the distillation tower through a second condenser pipe, and to the recovery tower through a third condenser pipe.

3. The energy-saving device for acetate production according to claim 1, characterized in that, Also includes: An esterification reboiler is provided outside the esterification tower. One end of the esterification reboiler is equipped with a steam pipe, and the other end is connected to the esterification tower. External steam is heated by the esterification reboiler and then transported into the esterification tower.

4. The energy-saving device for acetate production according to claim 1, characterized in that, Also includes: A first vacuum pump is installed on the distillation column.

5. The energy-saving device for acetate production according to claim 1, characterized in that, The top of the recovery tower has a head ester outlet, and a recovery pipe is connected to the head ester outlet.

6. The energy-saving device for acetate production according to claim 5, characterized in that, The recovery pipe is connected to a waste heat recovery pipe, which is connected to the recovery tower.

7. The energy-saving device for acetate production according to claim 6, characterized in that, A condensing heat exchanger is disposed at the connection between the recovery pipe and the waste heat recovery pipe.

8. The energy-saving device for acetate production according to claim 1, characterized in that, Also includes: A second vacuum pump is installed on the recovery tower.

Images