Sodium removal method and system for waste alkali butter

Abstract

The invention relates to a sodium removal method of waste alkali butter, which comprises the following steps: fully mixing waste alkali butter with an acetic acid solution to obtain a mixture; separating the mixture phase to obtain an oil phase and a water phase; and collecting the oil phase to obtain the butter after sodium removal. The acetic acid is used as the sodium removal agent, so that the trend of diffusion of sodium ions to the acetic acid solution can be enhanced, and the extraction efficiency of water on sodium is remarkably improved. Meanwhile, as the biodegradability of the acetic acid is very good, the subsequent treatment process of the water phase is relatively easy after phase separation. The water phase can be directly discharged into a sewage biochemical treatment plant and can also be discharged into a waste alkali oxidation reactor. The influence on the existing wastewater treatment facility is avoided.

Description

Technical Field

[0001] This application relates to the ethylene industry, and more particularly to the treatment of waste alkali butter. Background Technology

[0002] During the alkaline washing process, pyrolysis gas produces liquid polymers, which tend to be yellow and viscous, hence the common name "waste alkali grease." In ethylene plants, the usual treatment of waste alkali grease involves sending it along with the waste alkali to a waste alkali oxidation unit. After skimming and other treatments, it is separated from the waste alkali and sold as waste oil. However, with increasingly stringent environmental policies, waste alkali grease is now classified as hazardous waste and cannot be sold directly as a product. Therefore, further treatment of waste alkali grease is now necessary. However, if waste alkali grease is sent to a fuel oil boiler or waste liquid incinerator for incineration, the sodium ions in it will cause ash accumulation in the boiler's convection flue and corrosion of the furnace lining. If waste alkali grease is mixed with pyrolysis gasoline for hydrogenation, the sodium ions in it will poison the gasoline hydrogenation catalyst.

[0003] Therefore, the key to the resource utilization of waste lye butter is the removal of sodium ions. Currently, the industrially practical method for removing sodium ions from waste lye butter is a water washing process. This involves mixing the waste lye butter with water and allowing it to stand for a long time, causing the oil and water phases to separate. Sodium ions in the waste lye butter are transferred to the water phase, achieving the purpose of sodium removal. The limitations of this method are that the water washing process easily produces an emulsion layer, requiring the addition of a demulsifier; the separation effect between the water and oil phases depends on the standing time—the longer the standing time, the better the phase separation. According to the actual operating experience of a domestic petrochemical plant, to achieve the desired sodium removal effect, the standing time needs to be greater than 36 hours. Therefore, this process requires large equipment size, a large unit footprint, and significant investment. Furthermore, continuous operation is not possible, making this sodium removal process quite limited. Summary of the Invention

[0004] This application provides a method and system for removing sodium from waste lye butter to solve the technical problem of difficult sodium removal from waste lye butter.

[0005] In a first aspect, embodiments of this application provide a method for removing sodium from waste lye butter, the method comprising the following steps:

[0006] The waste alkali butter was thoroughly mixed with the acetic acid solution to obtain a mixture;

[0007] The mixture is then separated into an oil phase and an aqueous phase.

[0008] Collect the oil phase to obtain desodium-free butter.

[0009] In some embodiments of this application, the pH of the acetic acid solution is 3 to 5.

[0010] In some embodiments of this application, the waste alkali butter and acetic acid solution are thoroughly mixed using a static mixer.

[0011] In some embodiments of this application, the phase separation is performed using a disc centrifuge.

[0012] Secondly, embodiments of this application provide a sodium removal system for waste lye butter, the sodium removal system for waste lye butter comprising:

[0013] Acetic acid storage tanks, demineralized water storage tanks, and waste alkali butter storage tanks;

[0014] An acetic acid solution storage tank, wherein the acetic acid storage tank is connected to another acetic acid solution storage tank, and the demineralized water storage tank is connected to another acetic acid solution storage tank;

[0015] The mixer is connected to the waste alkali butter storage tank and the acetic acid solution storage tank.

[0016] A buffer tank, the mixer being connected to the buffer tank;

[0017] A phase separation device, wherein the buffer tank is connected to the phase separation device;

[0018] An oil phase storage tank and an aqueous phase storage tank are provided. The phase separation device is connected to the oil phase storage tank and the aqueous phase storage tank.

[0019] In some embodiments of this application, the desodiuming system for the waste alkali butter further includes a pH monitoring device for monitoring the pH of the acetic acid solution in the acetic acid solution storage tank.

[0020] In some embodiments of this application, the desodiuming system for the waste alkali butter further includes a first flow regulating valve and a second flow regulating valve. The acetic acid storage tank and the acetic acid solution storage tank are connected through the first flow regulating valve, and the waste alkali butter storage tank and the acetic acid solution storage tank are connected through the second flow regulating valve.

[0021] In some embodiments of this application, the mixer is a static mixer.

[0022] In some embodiments of this application, the phase separation device is a disc centrifuge.

[0023] In some embodiments of this application, the desodiuming system for waste lye butter further includes a level sensing device for sensing the liquid level in the acetic acid solution storage tank.

[0024] A third flow regulating valve is also installed on the pipeline connecting the acetic acid solution storage tank and the phase separation device, and the third flow regulating valve is communicatively connected to the liquid level sensing device.

[0025] The technical solutions provided in this application have the following advantages compared with the prior art:

[0026] The sodium removal method for waste alkali butter provided in this application uses acetic acid as a sodium removal agent, which enhances the tendency of sodium ions to diffuse into the acetic acid solution, thereby significantly improving the extraction efficiency of sodium from water. Furthermore, because acetic acid itself has excellent biodegradability, the subsequent treatment of the aqueous phase after phase separation is relatively easy and will not affect existing wastewater treatment facilities. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of a sodium removal system for waste lye butter provided in an embodiment of this application. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] Unless otherwise specified, the terminology used herein should be understood as having the meaning commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. In case of any conflict, this specification shall prevail.

[0032] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0033] Existing waste lye butter has technical problems with sodium removal.

[0034] The technical solution provided in this application is to solve the above-mentioned technical problems, and the general idea is as follows:

[0035] In a first aspect, embodiments of this application provide a method for removing sodium from waste lye butter, the method comprising the following steps:

[0036] S1: Thoroughly mix the waste alkali butter with the acetic acid solution to obtain a mixture;

[0037] S2: Separate the mixture phases to obtain an oil phase and an aqueous phase;

[0038] S3: Collect the oil phase to obtain desodium-free butter.

[0039] Experiments and production verification have shown that using acetic acid as a sodium removal agent can significantly improve the sodium extraction efficiency.

[0040] The inventors speculate that its mechanism of action is as follows:

[0041] Waste alkali grease is a byproduct of the alkali washing process. It is generally alkaline and contains primarily alkaline sodium salts such as sodium carbonate and sodium sulfide, as well as sodium hydroxide. When waste alkali grease is mixed with acetic acid solution, the alkaline anions (hydroxyl, carbonate, and sulfide ions) in the waste alkali grease react with the hydrogen ions in the acetic acid solution. This directly consumes the negative charge in the waste alkali grease and the positive charge in the acetic acid solution. The tendency for charge neutralization between the waste alkali grease and acetic acid solution inevitably enhances the diffusion of cations from the waste alkali grease into the acetic acid solution and enhances the diffusion of anions from the acetic acid solution into the waste alkali grease. Acetic acid solution is an excellent extractant for sodium ions, which readily diffuse into it. However, waste alkali grease is not a good extractant for acetate ions, which do not readily diffuse into it. Therefore, charge neutralization between the waste alkali grease and acetic acid solution will primarily occur through the diffusion of sodium ions from the waste alkali grease into the acetic acid solution. Therefore, this application uses acetic acid as a sodium removal agent, which can enhance the tendency of sodium ions to diffuse into the acetic acid solution, thereby significantly increasing the sodium extraction efficiency.

[0042] Furthermore, due to the excellent biodegradability of acetic acid, the subsequent treatment of the aqueous phase after phase separation is relatively easy. The aqueous phase can be directly discharged into a wastewater biological treatment plant or into a waste alkali oxidation reactor. It will not affect existing wastewater treatment facilities.

[0043] This application utilizes acetic acid as a sodium removal agent, which enhances the diffusion tendency of sodium ions into the acetic acid solution, thereby significantly increasing the sodium extraction efficiency. Furthermore, due to the excellent biodegradability of acetic acid, the subsequent treatment of the aqueous phase after phase separation is relatively easy. The aqueous phase can be directly discharged into a wastewater biological treatment plant or into a waste alkali oxidation reactor, without affecting existing wastewater treatment facilities.

[0044] In some embodiments of this application, the pH of the acetic acid solution is 3 to 5.

[0045] It is easy to understand that the beneficial effect of having a pH of 3 to 5 in the acetic acid solution is that it ensures a sufficiently high hydrogen ion concentration in the acetic acid solution, thereby ensuring extraction efficiency, while minimizing the amount of acetic acid used.

[0046] In some embodiments of this application, the waste alkali butter and acetic acid solution are thoroughly mixed using a static mixer.

[0047] It is easy to understand that using a static mixer to thoroughly mix waste alkali butter and acetic acid solution can enhance the mass transfer process through a high Reynolds number, thereby improving extraction efficiency. At the same time, the static reactor is small in size, allowing for compact installation and saving space. In some embodiments of this application, the static reactor also has distribution nozzles.

[0048] In some embodiments of this application, the phase separation is performed using a disc centrifuge.

[0049] It's easy to understand that disc centrifuges have the advantages of high settling area, high operational flexibility, cleanability, and continuous operation. Compared with traditional methods that rely on density difference for static sedimentation to separate the aqueous and oil phases, disc centrifuges offer advantages such as smaller footprint, higher separation efficiency, and higher separation accuracy.

[0050] Secondly, embodiments of this application provide a sodium removal system for waste lye butter, please refer to... Figure 1 The desodium removal system for the waste lye butter includes:

[0051] Acetic acid storage tank 001, demineralized water storage tank 002, and waste alkali butter storage tank 003;

[0052] Acetic acid solution storage tank 101, acetic acid storage tank 001 is connected to acetic acid solution storage tank 101, and demineralized water storage tank 002 is connected to acetic acid solution storage tank 101;

[0053] The mixer 102 is connected to the waste alkali butter storage tank 003 and the acetic acid solution storage tank 101.

[0054] Buffer tank 103, the mixer 102 is connected to the buffer tank 103;

[0055] Phase separation device 104, the buffer tank 103 is connected to the phase separation device 104;

[0056] The oil phase storage tank 106 and the aqueous phase storage tank 105 are connected together. The phase separation device 104 is connected to the oil phase storage tank 106 and the aqueous phase storage tank 105.

[0057] It is easy to understand that the acetic acid in the acetic acid storage tank 001 and the demineralized water in the demineralized water storage tank 002 will enter the acetic acid solution storage tank 101 and mix to form an acetic acid solution.

[0058] It is easy to understand that the waste alkali butter in the waste alkali butter storage tank 003 and the acetic acid solution in the acetic acid solution storage tank 101 will be mixed and extracted in the mixer 102.

[0059] It is readily understood that the phase separation device 104 will separate an aqueous phase and an oil phase, wherein the aqueous phase will enter the aqueous phase storage tank 105 and the oil phase will enter the oil phase storage tank 106. In some embodiments of this application, the aqueous phase storage tank 105 may be connected to an external wastewater treatment device 005. As an example, the wastewater treatment device 005 may be a waste alkali oxidation reactor. In some embodiments of this application, the oil phase storage tank 106 may be connected to an external grease treatment device 004, which may be, for example, a boiler, an incinerator, or a gasoline hydrogenation unit.

[0060] The desodium removal system for the waste lye butter can implement the method described in any embodiment of the first aspect, and therefore has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here.

[0061] In some embodiments of this application, the desodiuming system for the waste alkali butter further includes a pH monitoring device 204 for monitoring the pH of the acetic acid solution in the acetic acid solution storage tank 101.

[0062] In some embodiments of this application, the desodiuming system for waste alkali butter further includes a first flow regulating valve 201 and a second flow regulating valve 202. The acetic acid storage tank 001 is connected to the acetic acid solution storage tank 101 through the first flow regulating valve 201, and the waste alkali butter storage tank 003 is connected to the acetic acid solution storage tank 101 through the second flow regulating valve 202.

[0063] It is easy to understand that when the pH monitoring device 204 detects that the pH of the acetic acid solution is too high or too low, the flow rate of acetic acid or demineralized water can be adjusted by adjusting the opening of the first flow regulating valve 201 and the second flow regulating valve 202, thereby adjusting the pH of the acetic acid solution.

[0064] In some embodiments of this application, the mixer 102 is a static mixer 102.

[0065] It is easy to understand that by using a static mixer 102 to thoroughly mix waste alkali butter and acetic acid solution, the mass transfer process can be enhanced through a high Reynolds number, thereby improving extraction efficiency. At the same time, the static reactor is small in size, allowing for compact installation and saving space. In some embodiments of this application, the static reactor also has distribution nozzles.

[0066] In some embodiments of this application, the phase separation device 104 is a disc centrifuge.

[0067] It's easy to understand that disc centrifuges have the advantages of high settling area, high operational flexibility, cleanability, and continuous operation. Compared with traditional methods that rely on density difference for static sedimentation to separate the aqueous and oil phases, disc centrifuges offer advantages such as smaller footprint, higher separation efficiency, and higher separation accuracy.

[0068] In some embodiments of this application, the desodiuming system for waste lye butter further includes a level sensor 205, which is used to sense the liquid level in the acetic acid solution storage tank 101.

[0069] A third flow regulating valve 203 is also provided on the pipeline connecting the acetic acid solution storage tank 101 and the phase separation device 104. The third flow regulating valve 203 is communicatively connected to the liquid level sensing device 205.

[0070] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to industry standards. If there is no corresponding industry standard, then common international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0071] Example

[0072] This embodiment provides a sodium removal system for waste lye butter. Please refer to [link / reference]. Figure 1 The desodium removal system for the waste lye butter includes:

[0073] Acetic acid storage tank 001, demineralized water storage tank 002, and waste alkali butter storage tank 003;

[0074] Acetic acid solution storage tank 101, acetic acid storage tank 001 is connected to acetic acid solution storage tank 101, and demineralized water storage tank 002 is connected to acetic acid solution storage tank 101;

[0075] The mixer 102 is connected to the waste alkali butter storage tank 003 and the acetic acid solution storage tank 101.

[0076] Buffer tank 103, the mixer 102 is connected to the buffer tank 103;

[0077] Phase separation device 104, the buffer tank 103 is connected to the phase separation device 104;

[0078] The oil phase storage tank 106 and the aqueous phase storage tank 105 are connected together. The phase separation device 104 is connected to the oil phase storage tank 106 and the aqueous phase storage tank 105.

[0079] The desodium removal system for the waste alkali butter also includes a pH monitoring device 204 for monitoring the pH of the acetic acid solution in the acetic acid solution storage tank 101.

[0080] The desodium removal system for the waste alkali butter also includes a first flow regulating valve 201 and a second flow regulating valve 202. The acetic acid storage tank 001 is connected to the acetic acid solution storage tank 101 through the first flow regulating valve 201, and the waste alkali butter storage tank 003 is connected to the acetic acid solution storage tank 101 through the second flow regulating valve 202.

[0081] The mixer 102 is a static mixer 102. The phase separation device 104 is a disc centrifuge.

[0082] The desodium removal system for the waste alkali butter also includes a liquid level sensor 205, which is used to sense the liquid level in the acetic acid solution storage tank 101. A third flow regulating valve 203 is also provided on the pipeline connecting the acetic acid solution storage tank 101 and the phase separation device 104. The third flow regulating valve 203 is communicatively connected to the liquid level sensor 205.

[0083] This embodiment also provides a method for removing sodium from waste lye butter based on the above-mentioned waste lye butter desodiuming system, the method comprising the following steps:

[0084] Acetic acid from acetic acid storage tank 001 and demineralized water from demineralized water storage tank 002 are introduced into acetic acid solution storage tank 101 to form acetic acid solution. The pH of the acetic acid solution is monitored by pH monitoring device 204, and the pH of the acetic acid solution is controlled between 3 and 5 by adjusting the opening of the first flow regulating valve 201 and the second flow regulating valve 202.

[0085] Acetic acid solution in acetic acid solution storage tank 101 and waste alkali butter in waste alkali butter storage tank 003 are introduced into the static mixer 102 to fully mix the acetic acid solution and waste alkali butter for extraction, thereby obtaining a mixture.

[0086] The mixture in the static mixer 102 is introduced into the buffer tank 103 for storage;

[0087] The mixture in the buffer tank 103 is introduced into the disc centrifuge for phase separation to form an oil phase and an aqueous phase.

[0088] The oil phase is introduced into the oil phase storage tank 106 for storage, and the aqueous phase is introduced into the aqueous phase storage tank 105 for storage.

[0089] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0090] In this application, unless otherwise stated, directional terms such as "upper" and "lower" specifically refer to the drawing directions in the accompanying drawings. Furthermore, in the description of this application, the terms "comprising," "including," etc., mean "including but not limited to." Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this document, "and / or" describes the relationship between related objects, indicating that three relationships can exist; for example, A and / or B can represent: A alone, A and B simultaneously, or B alone. For relationships involving three or more related objects described using "and / or", it indicates that any one of the three related objects can exist alone, or at least two of them can exist simultaneously. For example, for A, and / or B, and / or C, it can mean that any one of A, B, and C exists alone, or any two of them exist simultaneously, or all three of them exist simultaneously. In this document, "at least one" means one or more, and "more than one" means two or more. "At least one", "at least one of the following", or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple. The "parts representation" involved in this application, such as parts by weight or parts by mass, indicates the proportional relationship between the components. In the proportional relationships involved in this application, the parameters that need to be described by proportion should be understood as the first term of the proportion in the order of description, and the proportion figures should be understood as the second term of the proportion. For example, if the mass ratio of substance A, substance B and substance C is 1:2:3, then substance A, substance B and substance C should correspond one-to-one with the proportion figures in the proportion in the order of description, that is, the mass of substance A: the mass of substance B: the mass of substance C = 1:2:3.

[0091] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for removing sodium from waste lye butter, characterized in that, The method includes the following steps: The waste alkali butter was thoroughly mixed with the acetic acid solution to obtain a mixture; The mixture is then separated into an oil phase and an aqueous phase. Collect the oil phase to obtain desodium-free butter.

2. The method for removing sodium from waste lye butter according to claim 1, characterized in that, The pH of the acetic acid solution is 3 to 5.

3. The method for removing sodium from waste lye butter according to claim 1, characterized in that, The waste alkali butter and acetic acid solution are thoroughly mixed using a static mixer.

4. The method for removing sodium from waste lye butter according to claim 1, characterized in that, The phase separation is performed using a disc centrifuge.

5. A sodium removal system for waste lye butter, characterized in that, The desodium removal system for the waste lye butter includes: Acetic acid storage tanks, demineralized water storage tanks, and waste alkali butter storage tanks; An acetic acid solution storage tank, wherein the acetic acid storage tank is connected to another acetic acid solution storage tank, and the demineralized water storage tank is connected to another acetic acid solution storage tank; The mixer is connected to the waste alkali butter storage tank and the acetic acid solution storage tank. A buffer tank, the mixer being connected to the buffer tank; A phase separation device, wherein the buffer tank is connected to the phase separation device; An oil phase storage tank and an aqueous phase storage tank are provided. The phase separation device is connected to the oil phase storage tank and the aqueous phase storage tank.

6. The sodium removal system for waste lye butter according to claim 5, characterized in that, The desodium removal system for the waste alkali butter also includes a pH monitoring device for monitoring the pH of the acetic acid solution in the acetic acid solution storage tank.

7. The sodium removal system for waste lye butter according to claim 5, characterized in that, The desodium removal system for the waste alkali butter also includes a first flow regulating valve and a second flow regulating valve. The acetic acid storage tank and the acetic acid solution storage tank are connected through the first flow regulating valve, and the waste alkali butter storage tank and the acetic acid solution storage tank are connected through the second flow regulating valve.

8. The desodiuming system for waste lye butter according to claim 5, characterized in that, The mixer is a static mixer.

9. The sodium removal system for waste lye butter according to claim 5, characterized in that, The phase separation device is a disc centrifuge.

10. The sodium removal system for waste lye butter according to claim 5, characterized in that, The desodium removal system for the waste lye butter also includes a level sensor, which is used to sense the liquid level in the acetic acid solution storage tank. A third flow regulating valve is also installed on the pipeline connecting the acetic acid solution storage tank and the phase separation device, and the third flow regulating valve is communicatively connected to the liquid level sensing device.

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