System for improving purity of byproduct ammonium sulfate in preparation of direct coal liquefaction catalyst

Abstract

The utility model relates to a system for improving the purity of a byproduct ammonium sulfate in preparation of a direct coal liquefaction catalyst. The system comprises a reaction device, a dosing device, an immersed membrane filtration device and an aeration device, the reaction device is used for reacting a medicament with an ammonium sulfate solution to separate out solid particles and maintaining the pH value of the solution to be stable; the dosing device is connected with the reaction device; the immersed membrane filtration device is connected with the reaction device; the immersed membrane filtration device is used for separating solid particles from an ammonium sulfate solution; a gas distributor is arranged in the immersed membrane filtration device and is connected with the aeration device; the aeration device is connected with the reaction device and is used for keeping the solid particles in a suspended state. Compared with the prior art, the device disclosed by the utility model has the advantages of high treatment efficiency, low medicament cost, avoidance of impurity introduction, simple process, easiness in operation and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of resource recycling of industrial wastewater, in particular to a system for improving the purity of by-product ammonium sulfate in the preparation of a direct coal liquefaction catalyst. Background Art

[0002] Direct coal liquefaction is an important technology for clean utilization of coal, which can reduce dependence on external petroleum resources and effectively ensure national energy security. In order to improve the efficiency of direct coal liquefaction and reduce energy consumption, a high-efficiency catalyst needs to be prepared and used on site. The wastewater generated in this process contains a large amount of ammonia and sulfate, which can be further utilized to obtain by-product ammonium sulfate solid. The preparation process of the catalyst uses ferrous sulfate and ammonia water as raw materials to react to form nano-scale highly active FeOOH solid. Ammonium sulfate is a by-product in the catalyst preparation process. The catalyst preparation process is one of the important steps in the direct coal liquefaction process.

[0003] However, the purity of the by-product ammonium sulfate that can be recovered is relatively low at present, and it is difficult to reach the industrial first-class standard. The reason is that the impurities in the water (for example: suspended particles, calcium ions, etc.) are not effectively removed and precipitate together into the solid product. In this regard, Chinese patent CN201910529988.3 (a method for treating ammonium sulfate concentrate from direct coal liquefaction) uses an Oslo crystallizer to avoid the doping of insoluble coal powder in the by-product ammonium sulfate solid, but it cannot avoid the co-precipitation of other soluble substances and ammonium sulfate, and the purity of the obtained ammonium sulfate is still low, only 95-98%. Chinese patent CN201710346996.5 (a treatment process for zero discharge and resource recycling of catalyst wastewater) proposes to use a combination of sodium carbonate, polyaluminum chloride, polymagnesium chloride and other combined agents to remove suspended particles and calcium ions in water, but at the same time, sodium ions, chloride ions and other impurity ions are added to the wastewater, and the purity of the by-product ammonium sulfate has not been substantially improved.

[0004] Therefore, there is an urgent need to seek a technology that has high processing efficiency and good economic benefits to improve the purity of by-product ammonium sulfate. Utility Model Content

[0005] The purpose of the utility model is to overcome the defects of the above-mentioned prior art and to propose a system for improving the purity of by-product ammonium sulfate in the preparation of coal direct liquefaction catalyst. By setting a reaction device, a dosing device, an immersed membrane filtration device, and an aeration device, the system has high processing efficiency, low reagent cost, avoids the introduction of impurities, has a simple process, and is easy to operate.

[0006] The purpose of the utility model can be achieved through the following technical solutions:

[0007] The utility model provides a system for improving the purity of by-product ammonium sulfate in the preparation of a direct coal liquefaction catalyst. The system comprises a reaction device, a dosing device, an immersed membrane filter device and an aeration device; the reaction device is used for reacting a reagent with an ammonium sulfate solution to precipitate solid particles and maintain the pH value of the solution stable; the dosing device is connected to the reaction device and is used for adding the reagent to the reaction device; the immersed membrane filter device is connected to the reaction device; the immersed membrane filter device is used for separating the solid particles from the ammonium sulfate solution; a gas distributor is provided inside the immersed membrane filter device, and the gas distributor is connected to the aeration device; the aeration device is connected to the reaction device, and the aeration device is continuously operated to keep the solid particles in a suspended state.

[0008] Preferably, the agent is selected from one or more combinations of ammonium oxalate, ammonium hydrogen oxalate, and a combination of oxalic acid and ammonia water.

[0009] Preferably, the dosing device comprises a drug storage tank and a drug pump; the drug storage tank and the reaction device are connected via the drug pump.

[0010] Preferably, the reaction device is provided with a feed port for the ammonium sulfate solution.

[0011] Preferably, the reaction device is provided with a discharge port; the discharge port of the reaction device is connected to the submerged membrane filtration device via a delivery pump.

[0012] Preferably, the ammonium sulfate solution is delivered to the feed port of the reaction device, and the reagent storage tank is connected to the drug addition port of the reaction device through a reagent pump; the discharge port of the reaction device is connected to the feed liquid inlet of the submerged membrane filtration device through a delivery pump.

[0013] Preferably, a membrane assembly is further provided in the submerged membrane filtration device; and the gas distributor is arranged directly below the membrane assembly.

[0014] Preferably, the membrane assembly is arranged directly above the gas distributor, and its projected area is smaller than the service area of ​​the gas distributor.

[0015] Preferably, the submerged membrane module may be in the form of a curtain type, that is, the membrane module is a submerged curtain type membrane module.

[0016] Preferably, the membrane component material may be polytetrafluoroethylene or polyvinylidene fluoride.

[0017] Preferably, the system further comprises a produced water tank.

[0018] Preferably, the water production pipeline of the submerged membrane filtration device is connected to the water production tank inlet through a water production pump.

[0019] Preferably, the membrane assembly is connected to the water production tank via a water production pipeline and a water production pump disposed on the water production pipeline.

[0020] Preferably, a backwash pump may be provided for periodically flushing the membrane assembly, the inlet of the backwash pump being connected to the production water tank, and the outlet of the backwash pump being connected to the production water pipeline.

[0021] Preferably, the water production tank is connected to a backwash pump, and the backwash pump is connected to a water production pipeline at the front end of the water production pump inlet.

[0022] Preferably, a sludge dewatering device may also be provided, and a feed port of the sludge dewatering device is connected to a sludge discharge port of the reaction device and the submerged membrane filtration device via a sludge pump.

[0023] Preferably, the effluent from the sludge dewatering device can be returned to the reaction device.

[0024] Preferably, a mud discharge port is provided at the bottom of the reaction device, and a mud discharge port is provided at the bottom of the submerged membrane filtration device; the mud discharge port at the bottom of the reaction device and the mud discharge port at the bottom of the submerged membrane filtration device are both connected to the sludge dewatering device through a sludge pump; the sludge dewatering device is provided with a liquid discharge end, and the sludge dewatering device is provided with a liquid discharge end connected to the reaction device.

[0025] Preferably, the mud discharge ports of the reaction device and the submerged membrane filtration device are connected to the same mud discharge pipeline and connected to a sludge pump.

[0026] Preferably, the reaction device is provided with a stirring mechanism and a sludge hopper for mixing the ammonium sulfate solution with the reagent; the stirring mechanism is arranged above the sludge hopper.

[0027] Preferably, the stirring mechanism may be a mechanical stirrer and / or a gas distributor.

[0028] Preferably, the reaction device is provided with an online pH detector to maintain the pH of the solution in the reaction device in the range of 4.0-9.5.

[0029] Compared with the prior art, the utility model has the following beneficial effects:

[0030] 1) The utility model discloses a system for improving the purity of by-product ammonium sulfate in the preparation of a direct coal liquefaction catalyst. The ammonium sulfate solution and the reagent are fully mixed and reacted in a reaction device to cause impurity ions to form solid particles and precipitate. The solid-liquid mixture is transported to an immersed membrane filter device, and the air continuously blown in by an aeration device keeps the particles in a suspended state. Subsequently, the particles are intercepted by a membrane component to obtain an ammonium sulfate solution with a high purity. The treatment efficiency is high, and suspended particles and calcium ions in water are effectively removed, while the introduction of impurities such as sodium ions is avoided, and the purity of the by-product ammonium sulfate is significantly improved.

[0031] 2) The utility model provides a system for improving the purity of by-product ammonium sulfate in the preparation of a direct coal liquefaction catalyst, which can alleviate the blockage of rear-end concentration and evaporation equipment and significantly reduce the cleaning frequency.

[0032] 3) The utility model provides a system for improving the purity of by-product ammonium sulfate in the preparation of a coal direct liquefaction catalyst. The reagent is easily available and inexpensive, the reagent cost is low, and the economic benefit is good.

[0033] 4) The utility model provides a system for improving the purity of by-product ammonium sulfate in the preparation of a direct coal liquefaction catalyst, which has a simple process flow and is easy to operate and maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The utility model is a schematic diagram of the structure of a system for improving the purity of by-product ammonium sulfate in the preparation of a direct coal liquefaction catalyst.

[0035] In the figure:

[0036] 1. Reaction device; 2. Chemical storage tank; 3. Chemical pump; 4. Delivery pump; 5. Immersed membrane filtration device; 6. Membrane assembly; 7. Gas distributor; 8. Aeration device; 9. Water production pump; 10. Water production tank; 11. Backwash pump; 12. Sludge pump; 13. Sludge dewatering device. DETAILED DESCRIPTION

[0037] The utility model is described in detail below in conjunction with the accompanying drawings and specific embodiments. The following embodiments will help those skilled in the art to further understand the utility model, but do not limit the utility model in any form. It should be pointed out that for those of ordinary skill in the art, several changes and improvements can be made without departing from the concept of the utility model. These all belong to the protection scope of the utility model.

[0038] Any features such as preparation methods, materials, structures or composition ratios that are not clearly described in this technical solution shall be deemed as common technical features disclosed in the prior art.

[0039] It should be noted that the directions or positional relationships indicated by "front", "back", "left", "right", "up", "down", "inside", "outside" and the like described in this application are based on the directions or positional relationships indicated in the accompanying drawings, and are intended to be more concise and clear when describing this application. They do not mean that the devices or components must have certain direction restrictions, and therefore cannot be used as limitations on this application. In addition, the embodiments described in this application are only part of the embodiments of the utility model and cannot represent all the embodiments. Other embodiments obtained by those skilled in the art without making creative efforts on this application should all fall within the protection scope of this utility model.

[0040] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] It should be noted that, in the present utility model, relational terms such as first and second, etc. are only used 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. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0042] The technical scheme is a system for improving the purity of by-product ammonium sulfate in the preparation of direct coal liquefaction catalyst, which includes a reaction device 1, a dosing device, an immersed membrane filter device 5, and an aeration device 8. The ammonium sulfate solution and the reagent (ammonium oxalate and / or ammonium hydrogen oxalate and / or a combination of oxalic acid and ammonia water) are fully mixed and reacted in the reaction device 1 to cause the impurity ions to form solid particles and precipitate; the solid-liquid mixture is transported to the immersed membrane filter device 5, and the air continuously blown in by the aeration device 8 keeps the particles in a suspended state; then the particles are intercepted by the membrane assembly 6 to obtain a high-purity ammonium sulfate solution.

[0043] like Figure 1As shown, the utility model is a system for improving the purity of by-product ammonium sulfate in the preparation of direct coal liquefaction catalyst. The ammonium sulfate solution is transported to the reaction device 1, and the reagent storage tank 2 is connected through the reagent pump 3 to transport the reagent to the reaction device 1 to achieve mixing and reaction between the two. The discharge port of the reaction device 1 is connected to the submerged membrane filtration device 5 through the delivery pump 4. The gas distributor 7 in the device is arranged directly below the membrane assembly 6 and is connected to the aeration device 8; the water production pipeline of the membrane assembly 6 is connected to the water production pump 9 to transport the water production to the water production tank 10. The bottom of the water production tank 10 is provided with an interface connected to the inlet of the backwash pump 11, and the outlet of the backwash pump 11 is connected to the water production pipeline at the front end of the inlet of the water production pump 9 to clean the membrane assembly 6. The mud discharge port at the bottom of the reaction device 1 and the mud discharge port at the bottom of the submerged membrane filtration device 5 are connected to the same mud discharge pipeline, and are connected to the sludge dewatering device 13 through the sludge pump 12; the discharge end of the sludge dewatering device 13 is connected and returned to the reaction device 1.

[0044] Example

[0045] refer to Figure 1 The present embodiment provides a system for improving the purity of by-product ammonium sulfate in the preparation of coal direct liquefaction catalyst, the system comprising a reaction device 1, a reagent storage tank 2, a reagent pump 3, a delivery pump 4, an immersed membrane filter device 5, a membrane assembly 6, a gas distributor 7, an aeration device 8, a water production pump 9, a water production tank 10, a backwash pump 11, a sludge pump 12, and a sludge dewatering device 13.

[0046] The reaction device is used for reacting the agent with the ammonium sulfate solution to precipitate solid particles and maintain the pH of the solution stable.

[0047] The submerged membrane filtration device 5 is used to separate solid particles from the ammonium sulfate solution.

[0048] The aeration device 8 is operated continuously to keep the solid particles in suspension.

[0049] The submerged membrane filtration device 5 is provided with a membrane assembly 6 and a gas distributor 7 inside. The gas distributor 7 is connected to the aeration device 8. The membrane assembly 6 is arranged directly above the gas distributor 7, and its projected area is smaller than the service area of ​​the gas distributor 7.

[0050] The agent is selected from one or more combinations of ammonium oxalate, ammonium hydrogen oxalate, and a combination of oxalic acid and ammonia water.

[0051] The reagent storage tank 2 and the reaction device 1 are connected via a first pipeline and a reagent pump 3 arranged on the first pipeline.

[0052] The reaction device 1 is provided with a discharge port; the discharge port of the reaction device 1 is connected to the submerged membrane filtration device 5 via a discharge pipeline and a delivery pump 4 provided on the discharge pipeline.

[0053] The ammonium sulfate solution is transported to the feed port of the reaction device 1, and the reagent storage tank 2 is connected to the drug addition port of the reaction device 1 through the reagent pump 3; the discharge port of the reaction device 1 is connected to the feed liquid inlet of the submerged membrane filtration device 5 through the delivery pump 4.

[0054] In this embodiment, the membrane assembly 6 is an immersed curtain membrane assembly, and the material of the membrane assembly 6 can be polytetrafluoroethylene or polyvinylidene fluoride.

[0055] The membrane assembly 6 is connected to the water production tank 10 via a water production pipeline and a water production pump 9 disposed on the water production pipeline.

[0056] The backwash pump 11 is used to regularly flush the membrane assembly 6 . The inlet of the backwash pump 11 is connected to the production water tank 10 , and the outlet of the backwash pump 11 is connected to the production water pipeline.

[0057] Preferably, a mud discharge port is provided at the bottom of the reaction device 1, and a mud discharge port is provided at the bottom of the submerged membrane filtration device 5; the mud discharge port at the bottom of the reaction device 1 and the mud discharge port at the bottom of the submerged membrane filtration device 5 are connected to a sludge dewatering device 13 through the same mud discharge pipe and a sludge pump 12 connected to the mud discharge pipe; the sludge dewatering device 13 is provided with a liquid discharge end, and the sludge dewatering device 13 is provided with a liquid discharge end connected to the reaction device 1.

[0058] The reaction device 1 is provided with a stirring mechanism for mixing the ammonium sulfate solution with the reagent and a sludge hopper; the stirring mechanism is arranged above the sludge hopper.

[0059] In this embodiment, the stirring mechanism is a mechanical stirrer (using an existing mechanical stirrer).

[0060] The reaction device 1 is provided with an online pH detector (using an existing online pH detector) to maintain the pH of the solution in the reaction device 1 in the range of 4.0-9.5.

[0061] The working steps of the above system for improving the purity of by-product ammonium sulfate in the preparation of direct coal liquefaction catalyst are as follows:

[0062] (1) Ammonium sulfate solution and ammonium oxalate are respectively transported to the reaction device 1, and the two are fully mixed and reacted under the action of a mechanical stirrer; an online pH detector is provided at the front end of the discharge port of the reaction device 1 to maintain the pH value of the solution in the range of 6.0-7.0. The solid-liquid mixture flows into the submerged membrane filtration device 5 through the delivery pump 4, and a part of the particles are discharged through the mud discharge port at the bottom of the reaction device 1.

[0063] (2) The solid-liquid mixture is transported to the submerged membrane filtration device 5, and the air is evenly diffused into the submerged membrane filtration device 5 through the gas distributor 7, so that the particles remain suspended. Under the suction action of the water production pump 9, the produced water passes through the membrane assembly 6 and is transported to the water production tank 10 to obtain a high-purity ammonium sulfate solution; the particles are intercepted by the membrane assembly 6 and discharged through the mud discharge port at the bottom of the submerged membrane filtration device 5.

[0064] (3) According to the operation conditions, the produced water pump 9 is shut down periodically and the backwash pump 11 is started to backwash the membrane assembly 6 with part of the produced water in the produced water tank 10 to remove dirt on the surface of the membrane assembly 6.

[0065] (4) Solid particles are discharged through the bottom sludge outlet of the reaction device 1 and the bottom sludge outlet of the submerged membrane filtration device 5, and transported to the sludge dewatering device 13 through the sludge pump 12; the discharge of the sludge dewatering device 13 is returned to the reaction device 1 for further processing.

[0066] The implementation examples of the present utility model are described to facilitate the understanding and use of the present utility model by ordinary technicians in the technical field. It is obvious that those familiar with the technology in the field can easily make various modifications to these embodiments and apply the general principles described here to other embodiments without creative work. Therefore, the present utility model is not limited to the above-mentioned embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present utility model without departing from the scope of the present utility model should be within the scope of protection of the present utility model.

Claims

1. A system for improving the purity of by-product ammonium sulfate in the preparation of direct coal liquefaction catalyst, characterized in that: The system comprises a reaction device (1), a dosing device, an immersed membrane filtration device (5), and an aeration device (8); The reaction device is used to react the agent with the ammonium sulfate solution to precipitate solid particles and maintain the pH of the solution stable; The dosing device is connected to the reaction device (1); The submerged membrane filtration device (5) is connected to the reaction device (1); The submerged membrane filtration device (5) is used to separate solid particles from the ammonium sulfate solution; The submerged membrane filtration device (5) is provided with a gas distributor (7) inside, and the gas distributor (7) is connected to an aeration device (8); The aeration device (8) is connected to the reaction device (1), and the aeration device (8) is used to keep the solid particles in a suspended state.

2. A system for improving the purity of by-product ammonium sulfate in the preparation of direct coal liquefaction catalyst according to claim 1, characterized in that: The drug adding device comprises a drug storage tank (2) and a drug pump (3); The reagent storage tank (2) and the reaction device (1) are connected via a reagent pump (3).

3. A system for improving the purity of by-product ammonium sulfate in the preparation of direct coal liquefaction catalyst according to claim 1, characterized in that: The reaction device (1) is provided with a discharge port; The discharge port of the reaction device (1) is connected to the submerged membrane filtration device (5) via a delivery pump (4).

4. The system for improving the purity of by-product ammonium sulfate in the preparation of direct coal liquefaction catalyst according to claim 1, characterized in that: The submerged membrane filtration device (5) is further provided with a membrane assembly (6); The gas distributor (7) is arranged directly below the membrane assembly (6).

5. A system for improving the purity of by-product ammonium sulfate in the preparation of direct coal liquefaction catalyst according to claim 4, characterized in that: The membrane assembly (6) is a submerged curtain membrane assembly.

6. A system for improving the purity of by-product ammonium sulfate in the preparation of direct coal liquefaction catalyst according to claim 4, characterized in that: The system also includes a water production tank (10); The membrane assembly (6) is connected to the water production tank (10) via a water production pipeline and a water production pump (9) disposed on the water production pipeline.

7. A system for improving the purity of by-product ammonium sulfate in the preparation of direct coal liquefaction catalyst according to claim 6, characterized in that: The water production tank (10) is connected to a backwash pump (11), and the backwash pump (11) is connected to a water production pipeline at the front end of the inlet of the water production pump (9).

8. The system for improving the purity of by-product ammonium sulfate in the preparation of direct coal liquefaction catalyst according to claim 1, characterized in that: The bottom of the reaction device (1) is provided with a mud discharge port, and the bottom of the submerged membrane filtration device (5) is provided with a mud discharge port; The mud discharge port at the bottom of the reaction device (1) and the mud discharge port at the bottom of the submerged membrane filtration device (5) are both connected to the sludge dewatering device (13) via a sludge pump (12); The sludge dewatering device (13) is provided with a liquid discharge end, and the sludge dewatering device (13) is provided with a liquid discharge end connected to the reaction device (1).

9. The system for improving the purity of by-product ammonium sulfate in the preparation of direct coal liquefaction catalyst according to claim 1, characterized in that: The reaction device (1) is provided with a stirring mechanism and a sludge hopper; The stirring mechanism is arranged above the sludge hopper.

10. The system for improving the purity of by-product ammonium sulfate in the preparation of direct coal liquefaction catalyst according to claim 1, characterized in that: The reaction device (1) is provided with an online pH detector for maintaining the pH of the solution in the reaction device (1) in the range of 4.0-9.5.

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