Polyether polyol deliming device

Abstract

The utility model relates to a polyether polyol deashing device, which belongs to the technical field of chemical engineering and comprises a neutralization reactor, a deashing device and a deashing device, the neutralization product filter and the ion adsorption equipment are sequentially connected with an outlet of the middle reactor. Compared with the prior art, the liquid to be treated and the precipitant are added into the neutralization reactor, more than 90% of metal ions are removed by a precipitation method through the neutralization product filter, and a small amount of metal ions and other anions are removed through the ion adsorption equipment, so that the polyhydric alcohol with ultralow ash content is obtained; the metal ion content of the polyether polyol treated by the device is less than or equal to 5ppm, so that the ash content is less than or equal to 0.0001 wt%.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical engineering, in particular to a deashing device for polyether polyol. Background Art

[0002] Polyether polyols are oligomers with ether bonds (-ROR-) in the main chain and more than 2 hydroxyl groups (-OH) in the terminal or side groups. They are produced by ring-opening polymerization of different monomers under the action of catalysts, such as ethylene oxide (EO), propylene oxide (PO), and butylene oxide (BO), to produce polyether polyols for various applications. These polyols react with polyisocyanates in the presence of added catalysts and other materials to produce polyurethane polymers, and manufacture rubber-like elastomers, soft and hard foams, fibers and other products. These polyurethane products have excellent flexibility, low temperature resistance, wear resistance, light shielding, and aging resistance. The ash content of polyether polyols is an important indicator affecting polymer materials, and its content affects the performance of polymers in molding processes such as extrusion, film blowing, and wire drawing. For example, in the spandex industry, in the spandex wire drawing process using polytetrahydrofuran diol as raw material, when the ash content is too high, it will cause problems such as increased breakage during fiber drawing and filter clogging, while the ash content in the polyurethane film blowing process affects the color value and transparency after film formation. Therefore, it is crucial to develop technologies to reduce the ash content in polymers.

[0003] The ash in polyether polyols mainly comes from catalysts including alkali metal hydroxides or alcohol salts, metal ions carried by raw and auxiliary materials, and other inorganic substances. The content of alkali metal catalysts in normal production industry is about 2000~10000ppm. There are currently two industrial solutions:

[0004] 1) Before the polymerization reaction is completed, the amount of catalyst is strictly controlled and the ion content and inorganic impurities in the raw and auxiliary materials are reduced, but the effect of controlling the ash content to a lower level is not obvious.

[0005] 2) After the polymerization reaction is completed, it is removed by precipitation, adsorption, washing and other methods. However, since additives need to be added, the amount added is difficult to control accurately. Abnormal amounts of alkali or excess acid will contaminate the product.

[0006] Patent CN102887995A discloses a method for removing alkali metal ions from polyether polyols by precipitation, wherein magnesium sulfate-water solution is used as a precipitant, and alkali metal ions and magnesium sulfate are reacted to form sulfate or sulfite, magnesium hydroxide and excess magnesium sulfate and / or magnesium sulfite precipitation solid phase, and then the dehydrated slurry is passed through a filtration system including a filter press to separate the molten polyether polyol phase from the precipitation solid phase. Patent US4460796A introduces a method for removing an alkaline catalyst by reacting with orthophosphoric acid at an equivalent ratio of 1.5 to 2.5: 3, and the salt formed can be subsequently removed by filtration. However, the above patents have some disadvantages and problems. The process recorded in the above patents is repeatedly interrupted during the filtration process, and the polyol is exposed to air to oxidize the hydroxyl group, thereby producing unqualified products. After adding a large amount of water, the water still needs to be removed, which greatly increases energy consumption. Utility Model Content

[0007] In order to reduce the ash content in polyether polyol, the utility model provides a polyether polyol deashing device.

[0008] The purpose of the utility model can be achieved through the following technical solutions:

[0009] A polyether polyol deashing device comprises: a neutralization reactor, the neutralization reactor is provided with a to-be-treated liquid inlet and a precipitant inlet; a neutralization product filter and an ion adsorption device connected to the neutralization reactor outlet in sequence.

[0010] Furthermore, the neutralization reactor is a kettle reactor, and the neutralization product filter is a candle filter.

[0011] Furthermore, a neutralization product delivery pump is provided between the neutralization reactor and the neutralization product filter.

[0012] Furthermore, the deashing device is also provided with a filter residue collecting tank, and the filter residue collecting tank is connected to the filter residue outlet of the neutralization product filter.

[0013] Furthermore, a valve is provided on the pipeline between the neutralization product filter and the filter residue collection tank.

[0014] Furthermore, the deashing device is also provided with a discharge delivery pump, and the discharge delivery pump is connected to the outlet of the filter residue collection tank.

[0015] Furthermore, the ion adsorption device comprises a connected cation adsorption column and an anion adsorption column; the column inlet pipeline of the cation adsorption column is connected to the product outlet of the neutralization product filter.

[0016] Furthermore, a neutralization product cooler is provided between the cation adsorption column and the neutralization product filter.

[0017] Furthermore, the particle size of the resin in the cation adsorption column is ≤500 μm, and the specific surface area is 200-2000 m 2 / g, pore volume ≥0.5ml / g.

[0018] Furthermore, the particle size of the resin in the anion adsorption column is ≤500 μm, and the specific surface area is 200-2000 m 2 / g, pore volume ≥0.5ml / g.

[0019] Compared with the prior art, the utility model has the following advantages:

[0020] (1) The utility model discloses a polyether polyol deashing device, which adds a liquid to be treated and a precipitant into a neutralization reactor, first removes more than 90% of metal ions by precipitation through a neutralization product filter, and then removes a small amount of metal ions and other anions through an ion adsorption device to obtain a polyol with ultra-low ash content. The metal ion content of the polyether polyol treated by the utility model is ≤5ppm, thereby ensuring that the ash content is ≤0.0001wt%.

[0021] (2) The utility model discloses a deashing device for polyether polyols, wherein a candle filter is used as a filter for neutralizing a product. The liquid to be treated does not contact the air when being filtered in the candle filter, thereby preventing the polyether polyols from being exposed to the air and causing the hydroxyl groups to oxidize, thereby causing the product to be unqualified.

[0022] (3) The utility model discloses a deashing device for polyether polyols, wherein the ion adsorption device of the deashing device comprises a cation adsorption column and an anion adsorption column connected to each other, and removes a small amount of remaining metal ions and other anions by resin adsorption. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of a polyether polyol deashing device in an embodiment;

[0024] As shown in the figure: 1-neutralization reactor; 2-neutralization product delivery pump; 3-neutralization product filter; 4-neutralization product cooler; 5-cation adsorption column; 6-anion adsorption column; 7-filter residue collection tank; 8-discharge delivery pump; 9-inlet for liquid to be treated; 10-precipitant inlet. DETAILED DESCRIPTION

[0025] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0026] Example

[0027] In order to reduce the ash content in polyether polyols to obtain ultra-low ash polyether polyols, wherein the metal ion content of the ultra-low ash polyether polyols is ≤5ppm and the ash content is ≤0.0001wt%, this embodiment provides a polyether polyol deashing device, the specific structure of which is shown in Figure 1 , comprising: a neutralization reactor 1, wherein the neutralization reactor 1 is provided with a to-be-treated liquid inlet 9 and a precipitant inlet 10; a neutralization product filter 3 and an ion adsorption device which are sequentially connected to the outlet of the neutralization reactor 1.

[0028] In this embodiment, the neutralization reactor 1 is a kettle reactor, which is provided with a stirring kettle to improve the neutralization reaction efficiency.

[0029] In this embodiment, the treated liquid inlet 9 and the precipitant inlet 10 are both arranged at the upper part of the neutralization reactor 1. The polyether polyol to be treated is injected through the treated liquid inlet 9, and the precipitant is injected through the precipitant inlet 10. The precipitant is an inorganic acid, which can be phosphoric acid, sulfuric acid, carbonic acid, etc., and reacts below pH ≤ 7.

[0030] In this embodiment, the neutralization product filter 3 is a candle filter. The treated liquid does not contact the air when filtered in the candle filter, which can prevent the polyether polyol from being exposed to air and oxidizing the hydroxyl groups, thereby causing the product to be unqualified; the neutralization product filter 3 is used to remove more than 90% of the metal ions present in the polyether polyol, and the removed metal ions are mainly alkali metal ions, such as Na, K, Ca, Mg, and Al.

[0031] In this embodiment, a neutralization product delivery pump 2 is provided between the neutralization reactor 1 and the neutralization product filter 3 , and one end of the neutralization product delivery pump 2 is connected to the bottom of the neutralization reactor 1 , and the other end is connected to the bottom of the neutralization product filter 3 .

[0032] In this embodiment, the deashing device is further provided with a filter residue collection tank 7, and the filter residue collection tank 7 is connected to the filter residue outlet of the neutralization product filter 3. More specifically, the filter residue outlet of the neutralization product filter 3 is located at the lower end of the neutralization product filter 3, and the filter residue flowing out through the filter residue outlet flows into the tank from the upper end of the filter residue collection tank 7.

[0033] In this embodiment, a valve is provided on the pipeline between the neutralization product filter 3 and the filter residue collection tank 7. Preferably, the valve is an electromagnetic valve.

[0034] In this embodiment, the deashing device is also provided with a discharge delivery pump 8, which is connected to the outlet of the filter residue collecting tank 7, and the solution in the filter residue collecting tank 7 is discharged through the discharge delivery pump 8, wherein the outlet of the filter residue collecting tank 7 is arranged at the bottom of the filter residue collecting tank 7.

[0035] In this embodiment, the ion adsorption device includes a connected cation adsorption column 5 and anion adsorption column 6; the head end of the cation adsorption column 5 is connected to the product outlet of the neutralization product filter 3, wherein the cation adsorption column 5 and the anion adsorption column 6 are connected end to end, and the ion removal liquid flowing out from the tail end of the anion adsorption column 6 is the product low-ash polyether polyol.

[0036] In this embodiment, a neutralization product cooler 4 is provided between the cation adsorption column 5 and the neutralization product filter 3, and the temperature of the liquid entering the cation adsorption column 5 is controlled by the neutralization product cooler 4, thereby ensuring a good ion exchange rate.

[0037] In this embodiment, the particle size of the resin in the cation adsorption column 5 is ≤500 μm, and the specific surface area is 200-2000 m 2 / g, pore volume ≥0.5ml / g.

[0038] In this embodiment, the particle size of the resin in the anion adsorption column 6 is ≤500 μm, and the specific surface area is 200-2000 m 2 / g, pore volume ≥0.5ml / g.

[0039] Working principle:

[0040] The deashing device provided in this embodiment first adds the liquid to be treated and the precipitant into the neutralization reactor 1, and uses the precipitation reaction principle to make more than 90% of the metal ions in the solution form precipitation, and then separates the precipitation through the neutralization product filter 3. The neutralization product filter 3 in the device is a candle filter. When the liquid to be treated is filtered in the candle filter, due to its structural characteristics, the liquid to be treated does not contact with the air.

[0041] Then, the solution obtained from the neutralization product filter is further filtered through an ion adsorption device. The ion adsorption device consists of a connected cation adsorption column 5 and anion adsorption column 6. After precipitation treatment, a small amount of metal ions and other anions still remain in the solution. This device utilizes the adsorption characteristics of resins for ions. When the solution passes through the cation adsorption column 5 and the anion adsorption column 6 in turn, the resin in the cation adsorption column 5 will adsorb metal ions, and the resin in the anion adsorption column 6 will adsorb other anions, thereby achieving the removal of the remaining small amount of ions. Finally, the metal ion content of the polyether polyol treated by the device can be controlled at ≤5ppm, ensuring that the ash content is ≤0.0001wt%, and obtaining an ultra-low ash polyether polyol product that meets the requirements.

[0042] The above is only the preferred embodiment of the utility model, and does not limit the utility model in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the utility model without departing from the technical solution of the utility model still belongs to the protection scope of the technical solution of the utility model.

Claims

1. A polyether polyol deashing device, characterized in that: include: A neutralization reactor (1), wherein the neutralization reactor (1) is provided with an inlet (9) for a liquid to be treated and an inlet (10) for a precipitant; A neutralization product filter (3) and an ion adsorption device are sequentially connected to the outlet of the neutralization reactor (1).

2. A polyether polyol deashing device according to claim 1, characterized in that: The neutralization product filter (3) is a candle filter.

3. A polyether polyol deashing device according to claim 1, characterized in that: A neutralization product delivery pump (2) is provided between the neutralization reactor (1) and the neutralization product filter (3).

4. A polyether polyol deashing device according to claim 1, characterized in that: The deashing device is further provided with a filter residue collection tank (7), and the filter residue collection tank (7) is connected to the filter residue outlet of the neutralization product filter (3).

5. A polyether polyol deashing device according to claim 4, characterized in that: A valve is provided on the pipeline between the neutralization product filter (3) and the filter residue collection tank (7).

6. A polyether polyol deashing device according to claim 4, characterized in that: The deashing device is further provided with a discharge delivery pump (8), and the discharge delivery pump (8) is connected to the outlet of the filter residue collection tank (7).

7. A polyether polyol deashing device according to claim 1, characterized in that: The ion adsorption device comprises a connected cation adsorption column (5) and an anion adsorption column (6); the column inlet pipeline of the cation adsorption column (5) is connected to the product outlet of the neutralization product filter (3).

8. A polyether polyol deashing device according to claim 7, characterized in that: A neutralization product cooler (4) is provided between the cation adsorption column (5) and the neutralization product filter (3).

9. A polyether polyol deashing device according to claim 7, characterized in that: The particle size of the resin in the cation adsorption column (5) is ≤500 μm, and the specific surface area is 200-2000 m 2 / g, pore volume ≥0.5ml / g.

10. A polyether polyol deashing device according to claim 7, characterized in that: The particle size of the resin in the anion adsorption column (6) is ≤500 μm, and the specific surface area is 200-2000 m 2 / g, pore volume ≥0.5ml / g.

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