Method for cleaning blockage material of polycarbonate production device

Abstract

The invention belongs to the technical field of chemical engineering, and particularly relates to a cleaning method for a blocked material of a polycarbonate production device. According to the invention, a detergent is adopted to clean the blocking material in the polycarbonate production device, the detergent comprises 66-90 parts of phenol, 9.5-30 parts of diphenyl carbonate and 0.5-4 parts of a volatile basic catalyst, and the boiling point of the volatile basic catalyst is less than 130 DEG C. The detergent provided by the invention is used for cleaning blockage materials in the polycarbonate production device, does not introduce any impurities, meets the pressure-bearing requirement of the polycarbonate production device, and is good in actual cleaning effect, simple to operate and energy-saving.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical industry, and in particular relates to a method for cleaning blockages in a polycarbonate production device. Background Art

[0002] As an engineering plastic with excellent comprehensive performance and wide application fields, the demand for polycarbonate (PC) is increasing year by year. At present, the melt transesterification method has become the mainstream production process of PC due to its advantages such as not using toxic phosgene and no wastewater pollution. However, high temperature is required in the melt transesterification production process. Under this production condition, rearrangement, cross-linking and other by-products are easily produced. Severe rearrangement and cross-linking products adhere to the reactor and pipeline, which will not only have an adverse effect on the quality of PC products, but also cause blockage of the reactor and pipeline of the device due to long-term accumulation, affecting the normal production of the device and bringing safety hazards to the device. In addition, when the device is operated abnormally, such as excessive addition of catalyst under abnormal conditions, uneven dispersion, and abnormal overheating of the device, a large amount of rearrangement and cross-linking products will be produced. Severe rearrangement and cross-linking products are almost insoluble in any solvent and do not melt at a temperature below 500°C. In similar situations, when cleaning the blockage in the reactor of the device, it is usually necessary to add diphenyl carbonate into the reactor and stir and dissolve it several times under high temperature (260~280℃) conditions until it is clean. This operation requires high energy consumption, takes a long time, and is complicated to operate. When cleaning the blocked transmission pipeline, it can only be solved by cutting the blocked pipeline and using high-temperature calcination. This method is not only time-consuming and difficult to operate, but also cannot effectively treat the pipelines of the entire device. Therefore, it is very necessary to study more effective treatment methods.

[0003] The traditional alcoholysis method can handle the blockage of PC reactors and pipelines, but there are the following problems: 1) During alcoholysis, a strong base with a mass fraction of 10-40% is usually added as a catalyst. A large amount of base enters the PC production device, which is easy to cause residue in the device. The extremely small amount of residual base will affect the polymerization of PC (usually 10 -4 ~10 -6ppm, too high alkali content will increase the rearrangement product); 2) alcoholysis usually adopts higher temperature, at higher temperature, the saturated vapor pressure of alcohol is higher (methanol at 130℃, the gauge pressure of saturated vapor pressure is 0.745MPa), that is, alcoholysis usually requires a certain pressure, and the melt ester exchange method for producing PC adopts high temperature vacuum conditions (pressure ≤0.7MPa), so the reactor and pipeline cannot meet the pressure requirements of alcoholysis reaction; 3) Because PC and its rearrangement and cross-linking products are not soluble in alcohol, the alcoholysis process is slow, and additional solvents are usually added to increase the alcoholysis reaction rate. The solvent is usually a good solvent for PC, such as 2-methyl-tetrahydrofuran, benzene, toluene, etc., but the above solvents cannot dissolve highly cross-linked and rearranged products, and the above PC good solvents cannot be used to accelerate the reaction rate. Moreover, it is difficult to completely remove the above solvents introduced into the PC polymerization system, which will affect the subsequent start-up production. Summary of the invention

[0004] The object of the present invention is to provide a method for cleaning blockages in a polycarbonate production device. The detergent provided by the present invention is used for cleaning blockages in a polycarbonate production device without introducing any impurities, meeting the pressure requirements of the polycarbonate production device, and having good actual cleaning effect, simple operation, and energy saving.

[0005] In order to achieve the above object, the present invention provides the following technical solutions: The present invention provides a method for cleaning blockage in a polycarbonate production device, wherein the polycarbonate production device comprises a reactor and / or a pipeline; the method comprises the following steps: Using a detergent to clean the blockage in the polycarbonate production device; The detergent comprises the following components in parts by weight: 66-90 parts of phenol, 9.5-30 parts of diphenyl carbonate, and 0.5-4 parts of a volatile alkaline catalyst, wherein the boiling point of the volatile alkaline catalyst is less than 130°C.

[0006] Preferably, the volatile alkaline catalyst comprises tetramethylammonium hydroxide and / or tetraethylammonium hydroxide.

[0007] Preferably, the detergent comprises the following components in parts by mass: 80 parts of phenol, 19 parts of diphenyl carbonate, and 1 part of a volatile alkaline catalyst.

[0008] Preferably, the cleaning comprises the following steps: delivering the detergent to the polycarbonate production unit; heating and steaming a polycarbonate production device containing the detergent; After the cooking is completed, the cooked detergent is discharged from the polycarbonate production device.

[0009] Preferably, before and / or during the steaming, the method further comprises: connecting the polycarbonate production device containing the detergent to a vacuum system, and evacuating the polycarbonate production device containing the detergent through the vacuum system.

[0010] Preferably, the cleaning is repeated; the volume of the detergent during each cleaning accounts for 1 / 3 to 2 / 3 of the total volume remaining in the polycarbonate production device excluding the blockage material.

[0011] Preferably, the cleaning is repeated; the cooking time during each cleaning is 1 to 3 hours.

[0012] Preferably, the cooking temperature is 90-130°C.

[0013] Preferably, after the cleaning is completed, the method further comprises: heating the cleaned polycarbonate production device to remove the volatile alkaline catalyst in the detergent remaining in the polycarbonate production device.

[0014] The present invention provides a method for cleaning blockages in a polycarbonate production device, wherein the polycarbonate production device includes a reactor and / or a pipeline; and comprises the following steps: using a detergent to clean the blockages in the polycarbonate production device; the detergent includes the following components by mass: 66-90 parts of phenol, 9.5-30 parts of diphenyl carbonate, and 0.5-4 parts of a volatile alkaline catalyst, wherein the boiling point of the volatile alkaline catalyst is less than 130°C. The present invention aims at the problem of blockages caused by heavy rearrangement and cross-linking products adhering to the reactor and pipelines in the production process of non-phosgene polycarbonate, and uses a detergent to clean the blockages in the reactor and pipelines. The detergent provided by the present invention uses phenol as a depolymerizing agent, DPC as a solvent, and a volatile alkaline catalyst, wherein DPC and phenol are both raw materials used in the PC production process, trace residues will not affect the restart of the device, the volatile alkaline catalyst content is small, and the easily decomposable residual catalyst can be completely decomposed at 130°C, and the catalyst can be removed by nitrogen purging, which will not affect the restart. The cleaning method provided by the present invention realizes the removal of blockages in the reactor and pipeline of the polycarbonate production device by designing a reasonable detergent component ratio, thereby improving the efficiency and flexibility of the blockage cleaning. The cleaning method provided by the present invention does not introduce any impurities, meets the pressure requirements of the polycarbonate production device, and does not affect the normal production of the device. It solves the problems of high difficulty and long time consumption when cleaning blockages in the reactor and pipeline by traditional methods (cutting the blocked pipeline and high-temperature calcination), realizes the removal of agglomerated materials in the reactor and pipeline of the polycarbonate production device, saves the cost of cleaning agglomerated materials, improves the efficiency of the device in dealing with such problems, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a flow chart of using detergent to clean blockage in a polycarbonate production device in an embodiment of the present invention; Figure 1 In the middle: 1 is a liquid storage tank, 2 is a pneumatic pump, 3 is heat transfer oil tracing, 4 is a reactor or pipeline plugging material, 5 is a waste liquid tank, and 6 is a vacuum pump. DETAILED DESCRIPTION

[0016] The present invention provides a method for cleaning blockage in a polycarbonate production device, wherein the polycarbonate production device comprises a reactor and / or a pipeline; the method comprises the following steps: Using a detergent to clean the blockage in the polycarbonate production device; The detergent comprises the following components in parts by weight: 66-90 parts of phenol, 9.5-30 parts of diphenyl carbonate, and 0.5-4 parts of a volatile alkaline catalyst, wherein the boiling point of the volatile alkaline catalyst is less than 130°C.

[0017] In the present invention, unless otherwise specified, all preparation raw materials / components are commercially available products well known to those skilled in the art.

[0018] In terms of mass fraction, the detergent provided by the present invention comprises 66 to 90 parts of phenol, preferably 70 to 87 parts, more preferably 75 to 85 parts, and specifically 60 parts, 66 parts, 80 parts or 90 parts in the embodiment. In the present invention, the phenol is used as a depolymerizing agent.

[0019] The detergent provided by the present invention comprises 9.5 to 30 parts of diphenyl carbonate, preferably 10 to 25 parts, more preferably 15 to 30 parts, and specifically 39.9 parts, 30 parts, 19 parts or 9.5 parts in the embodiment, based on the mass fraction of the phenol. In the present invention, the diphenyl carbonate is used as a solvent.

[0020] The detergent provided by the present invention comprises 0.5 to 4 parts of a volatile alkaline catalyst, preferably 0.8 to 2 parts, and specifically 0.1 parts, 4 parts, 1 part or 0.5 parts, based on the mass fraction of the phenol. In the present invention, the boiling point of the volatile alkaline catalyst is less than 130° C. The volatile alkaline catalyst preferably comprises tetramethylammonium hydroxide and / or tetraethylammonium hydroxide, and specifically tetraethylammonium hydroxide in the embodiment.

[0021] In the present invention, the polycarbonate production device is a production device used in the non-phosgene polycarbonate production process, specifically a melt transesterification polycarbonate production device. The plugging material is a heavy rearrangement and cross-linking product adhered to the polycarbonate production device (reactor and / or pipeline).

[0022] The detergent provided by the invention is used for cleaning the reactor and pipeline blockages of carbonate production equipment, and has mild reaction, efficient depolymerization and simple post-treatment.

[0023] The invention provides a method for cleaning blockages in a polycarbonate production device. The polycarbonate production device comprises a reactor and / or a pipeline.

[0024] In the present invention, the cleaning preferably comprises the following steps: delivering the detergent to the polycarbonate production unit; heating and steaming a polycarbonate production device containing the detergent; After the cooking is completed, the cooked detergent is discharged from the polycarbonate production device.

[0025] The present invention delivers the detergent to the polycarbonate production device.

[0026] In a specific embodiment of the present invention, the present invention preferably uses an external pump to deliver the detergent from the pipeline drain of the polycarbonate production device. In the present invention, the cleaning is repeated, and the volume of the detergent in each cleaning preferably accounts for 1 / 3 to 2 / 3 of the total volume of the polycarbonate production device except for the plugging material, and more preferably 1 / 2 to 2 / 3.

[0027] Then, the present invention closes the valve of the reactor and / or pipeline to be cleaned, and heats the polycarbonate production device containing the detergent inside for steaming. In the present invention, the steaming temperature is preferably 90-130°C, more preferably 95-120°C, and further preferably 100-115°C, and in the embodiment, it is specifically 90°C, 110°C or 130°C. The cleaning is repeated. The steaming time for each cleaning is preferably 1-3h, and in the embodiment, it is specifically 1h, 2h or 3h.

[0028] In the present invention, before and / or during the cooking, the present invention preferably further comprises: connecting the polycarbonate production device containing the detergent to a vacuum system. The present invention preferably evacuates the polycarbonate production device containing the detergent through the vacuum system.

[0029] In the present invention, since the melt ester exchange production equipment is equipped with a multi-stage vacuum system, the reactor and / or pipeline segment to be cleaned must remain connected to the vacuum system and unobstructed to ensure that a small amount of detergent evaporated due to temperature increase during the cooking process can be smoothly discharged through the vacuum system to prevent the reactor and pipeline from being pressurized.

[0030] After the cooking is finished, the present invention discharges the cooked detergent from the polycarbonate production device. In the present invention, the cooked detergent is discharged from the drain of the pipeline of the polycarbonate production device.

[0031] In the present invention, the cleaning is repeated, and the number of cleaning is preferably 2 to 5 times, specifically 2 times, 3 times, 4 times or 5 times. The present invention uses the above cleaning method to repeatedly clean the polycarbonate production device until the blockage in the polycarbonate production device is completely removed.

[0032] In the present invention, after the cleaning is completed, the cleaning method preferably further comprises: heating the cleaned polycarbonate production device to remove the volatile alkaline catalyst in the detergent remaining in the polycarbonate production device.

[0033] In the present invention, after the cleaning is completed, the detergent after cooking is discharged. The present invention preferably reheats the cleaned polycarbonate production device to ensure the removal of the volatile alkaline catalyst. Since the solvent (diphenyl carbonate) and the depolymerizing agent (phenol) in the detergent are both raw materials used in the PC production process, trace residues will not affect the restart of the device. The volatile alkaline catalyst is easy to decompose. The residual volatile alkaline catalyst can be completely decomposed at 130°C. The catalyst can be removed by nitrogen purging, which will not affect the restart of the device.

[0034] The present invention has the following beneficial effects: Compared with the existing cleaning of PC reactors and pipelines caused by severe rearrangement and cross-linking, the cleaning method provided by the present invention is highly operable, does not require cleaning of the reactor under high temperature conditions, and avoids the use of high-temperature calcination after cutting the blocked pipeline. The cleaning time and labor time are greatly shortened, and a convenient cleaning method can be implemented at places where cleaning cannot be achieved by cutting, such as inlets and outlets of machine pumps.

[0035] In order to further illustrate the present invention, the technical solutions provided by the present invention are described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0036] Parts in the following examples are all parts by mass.

[0037] Example 1 like Figure 1As shown, the detergent (60 parts of phenol, 39.9 parts of diphenyl carbonate, and 0.1 parts of tetraethylammonium hydroxide) is transported from the pipeline drain into the reactor and pipeline to be cleaned by an external pneumatic pump, and filled to 1 / 2 of the remaining volume of the reactor and pipeline. The valve at the drain of the reactor and pipeline to be cleaned is closed, and the reactor and pipeline section to be cleaned must be connected to the vacuum system. The reactor and pipeline to be cleaned are heated to control the reaction temperature to 110 °C. After high-temperature cooking for 2 hours, the depolymerized solution (i.e., the detergent after cooking) is discharged from the drain to the waste liquid tank, and the reactor and pipeline are cleaned 5 times. After the cleaning liquid is discharged, it is heated again and purged with nitrogen to ensure the removal of the catalyst.

[0038] Example 2 like Figure 1 As shown, the detergent (66 parts of phenol, 30 parts of diphenyl carbonate, and 4 parts of tetraethylammonium hydroxide) is transported from the pipeline drain into the reactor and pipeline to be cleaned by an external pneumatic pump, and filled to 1 / 2 of the remaining volume of the reactor and pipeline. The valve at the drain of the reactor and pipeline to be cleaned is closed, and the reactor and pipeline section to be cleaned must be connected to the vacuum system. The reactor and pipeline to be cleaned are heated to control the reaction temperature to 110 °C. After high-temperature cooking for 2 hours, the depolymerized solution is discharged from the drain to the waste liquid tank, and the reactor and pipeline are cleaned three times. After the cleaning liquid is discharged, it is heated again and purged with nitrogen to ensure the removal of the catalyst.

[0039] Example 3 like Figure 1 As shown, the detergent (phenol 80 parts, diphenyl carbonate 19 parts, tetraethylammonium hydroxide 1 part) is transported from the pipeline drain into the reactor and pipeline to be cleaned by an external pneumatic pump, and filled to 1 / 2 of the remaining volume of the pipeline, and the valve of the reactor and pipeline drain to be cleaned is closed. The reactor and pipeline section to be cleaned need to be connected to the vacuum system, and the reactor and pipeline to be cleaned are heated to control the reaction temperature to 110 °C. After high-temperature cooking for 2 hours, the depolymerized solution is discharged from the drain to the waste liquid tank, and the reactor and pipeline are cleaned twice. After the cleaning liquid is discharged, it is heated again and purged with nitrogen to ensure the removal of the catalyst.

[0040] Example 4 like Figure 1As shown, the detergent (90 parts of phenol, 9.5 parts of diphenyl carbonate, and 0.5 parts of tetraethylammonium hydroxide) is transported from the pipeline drain into the reactor and pipeline to be cleaned by an external pneumatic pump, and filled to 1 / 2 of the remaining volume of the reactor and pipeline. The valve at the drain of the reactor and pipeline to be cleaned is closed, and the reactor and pipeline section to be cleaned must be connected to the vacuum system. The reactor and pipeline to be cleaned are heated to control the reaction temperature to 110 °C. After high-temperature cooking for 2 hours, the depolymerized solution is discharged from the drain to the waste liquid tank, and the reactor and pipeline are cleaned three times. After the cleaning liquid is discharged, it is heated again and purged with nitrogen to ensure the removal of the catalyst.

[0041] By comparing Examples 1 to 4, it can be seen that under the same cooking temperature and time, different detergent ratios result in different times of completely cleaning the reactor and pipeline blockages. In Example 3, when the detergent composition is: 80 parts of phenol, 19 parts of diphenyl carbonate, and 1 part of tetraethylammonium hydroxide, the number of times used to clean the reactor and pipeline is the least, indicating that under the same conditions, this detergent component ratio is most suitable for cleaning the reactor and pipeline blockages.

[0042] Example 5 like Figure 1 As shown, the detergent (phenol 80 parts, diphenyl carbonate 19 parts, tetraethylammonium hydroxide 1 part) is transported from the pipeline drain into the reactor and pipeline to be cleaned by an external pneumatic pump, and filled to 1 / 3 of the remaining volume of the reactor and pipeline, and the valve of the reactor and pipeline drain to be cleaned is closed. The reactor and pipeline section to be cleaned need to be connected to the vacuum system, and the reactor and pipeline to be cleaned are heated to control the reaction temperature to 110 ℃. After high-temperature cooking for 2 hours, the depolymerized solution is discharged from the drain to the waste liquid tank, and the reactor and pipeline are cleaned 4 times. After the cleaning liquid is discharged, it is heated again and purged with nitrogen to ensure the removal of the catalyst.

[0043] Example 6 like Figure 1 As shown, the detergent (phenol 80 parts, diphenyl carbonate 19 parts, tetraethylammonium hydroxide 1 part) is transported from the pipeline drain into the reactor and pipeline to be cleaned by an external pneumatic pump, and filled to 2 / 3 of the remaining volume of the reactor and pipeline, and the valve of the reactor and pipeline drain to be cleaned is closed. The reactor and pipeline section to be cleaned need to be connected to the vacuum system, and the reactor and pipeline to be cleaned are heated to control the reaction temperature to 110 °C. After high-temperature cooking for 2 hours, the depolymerized solution is discharged from the drain to the waste liquid tank, and the reactor and pipeline are cleaned twice. After the cleaning liquid is discharged, it is heated again and purged with nitrogen to ensure the removal of the catalyst.

[0044] Compared with Examples 5-6, when other conditions remain unchanged, increasing the amount of detergent added is beneficial to the removal of blockages. When the detergent is filled to 1 / 2 or more of the remaining volume of the reactor and pipeline, there is no difference in the number of times used to clean the reactor and pipeline blockages.

[0045] Example 7 like Figure 1 As shown, the detergent (phenol 80 parts, diphenyl carbonate 19 parts, tetraethylammonium hydroxide 1 part) is transported from the pipeline drain into the reactor and pipeline to be cleaned by an external pneumatic pump, and filled to 1 / 2 of the remaining volume of the reactor and pipeline, and the valve of the reactor and pipeline drain to be cleaned is closed. The reactor and pipeline section to be cleaned need to be connected to the vacuum system, and the reactor and pipeline to be cleaned are heated to control the reaction temperature to 130 °C. After high-temperature cooking for 2 hours, the depolymerized solution is discharged from the drain to the waste liquid tank, and the reactor and pipeline are cleaned twice. After the cleaning liquid is discharged, it is heated again and purged with nitrogen to ensure the removal of the catalyst.

[0046] Example 8 like Figure 1 As shown, the detergent (phenol 80 parts, diphenyl carbonate 19 parts, tetraethylammonium hydroxide 1 part) is transported from the pipeline drain into the reactor and pipeline to be cleaned by an external pneumatic pump, and filled to 1 / 2 of the remaining volume of the reactor and pipeline, and the valve of the reactor and pipeline drain to be cleaned is closed. The reactor and pipeline section to be cleaned need to be connected to the vacuum system, and the reactor and pipeline to be cleaned are heated to control the reaction temperature to 90 °C. After high-temperature cooking for 2 hours, the depolymerized solution is discharged from the drain to the waste liquid tank, and the reactor and pipeline are cleaned three times. After the cleaning liquid is discharged, it is heated again and purged with nitrogen to ensure the removal of the catalyst.

[0047] Compared with Examples 7-8, when other conditions remain unchanged, increasing the reaction temperature is beneficial to the removal of blockages in Example 3. However, when the temperature is increased to 110°C or above, there is no difference in the number of times used to clean the reactor and pipeline blockages.

[0048] Example 9 like Figure 1 As shown, the detergent (phenol 80 parts, diphenyl carbonate 19 parts, tetraethylammonium hydroxide 1 part) is transported from the pipeline drain into the reactor and pipeline to be cleaned by an external pneumatic pump, and filled to 1 / 2 of the remaining volume of the reactor and pipeline, and the valve of the reactor and pipeline drain to be cleaned is closed. The reactor and pipeline section to be cleaned need to be connected to the vacuum system, and the reactor and pipeline to be cleaned are heated to control the reaction temperature to 110 °C. After high-temperature cooking for 1 h, the depolymerized solution is discharged from the drain to the waste liquid tank, and the reactor and pipeline are cleaned by repeating 4 times. After the cleaning liquid is discharged, it is heated again and purged with nitrogen to ensure the removal of the catalyst.

[0049] Example 10 like Figure 1 As shown, the detergent (phenol 80 parts, diphenyl carbonate 19 parts, tetraethylammonium hydroxide 1 part) is transported from the pipeline drain into the reactor and pipeline to be cleaned by an external pneumatic pump, and filled to 1 / 2 of the remaining volume of the reactor and pipeline, and the valve of the reactor and pipeline drain to be cleaned is closed. The reactor and pipeline section to be cleaned need to be connected to the vacuum system, and the reactor and pipeline to be cleaned are heated to control the reaction temperature to 110 °C. After high-temperature cooking for 3 hours, the depolymerized solution is discharged from the drain to the waste liquid tank, and the reactor and pipeline are cleaned twice. After the cleaning liquid is discharged, it is heated again and purged with nitrogen to ensure the removal of the catalyst.

[0050] Compared with Examples 9-10, when other conditions remain unchanged, increasing the cooking time is beneficial to the removal of blockages. However, when the cooking time is 2 h or more, there is no difference in the number of times used to clean the reactor and pipeline blockages.

[0051] From the above embodiments, it can be seen that the cleaning method provided by the present invention comprises: using an external pump to transport the detergent from the pipeline drain into the reactor and pipeline to be cleaned, after filling the reactor and pipeline, closing the valve of the drain of the reactor and pipeline to be cleaned, and heating the reactor and pipeline to be cleaned to control the reaction temperature. After high-temperature cooking, the depolymerized solution is discharged from the drain, and the reactor and pipeline can be cleaned again after repeated several times. After the detergent is discharged, it is heated again, and the catalyst can be removed by nitrogen purging without affecting the normal production of the device. The present invention realizes the removal of the blockage of the reactor and pipeline of the polycarbonate production device by designing a reasonable detergent component ratio, addition amount, reaction boiling temperature, and boiling time, and after repeated cleaning, the efficiency and flexibility of the blockage cleaning are improved. The cleaning method provided by the present invention solves the problems of high difficulty in operation and long time consumption when cleaning the reactor and pipeline blockage by the traditional method (cutting the blocked pipeline and high-temperature calcination), realizes the removal of the agglomerated material of the reactor and pipeline of the polycarbonate production device, saves the cost of cleaning the agglomerated material, improves the efficiency of the device in dealing with such problems, and has broad application prospects.

[0052] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for cleaning blockage in a polycarbonate production device, wherein the polycarbonate production device comprises a reactor and / or a pipeline; characterized in that: The following steps are involved: Using a detergent to clean the blockage in the polycarbonate production device; The detergent comprises the following components in parts by weight: 66-90 parts of phenol, 9.5-30 parts of diphenyl carbonate, and 0.5-4 parts of a volatile alkaline catalyst, wherein the boiling point of the volatile alkaline catalyst is less than 130°C.

2. The method for cleaning blockage in a polycarbonate production device according to claim 1, characterized in that: The volatile alkaline catalyst includes tetramethylammonium hydroxide and / or tetraethylammonium hydroxide.

3. The method for cleaning blockage in a polycarbonate production device according to claim 1 or 2, characterized in that: The detergent comprises the following components in parts by mass: 80 parts of phenol, 19 parts of diphenyl carbonate and 1 part of a volatile alkaline catalyst.

4. The method for cleaning blockage in a polycarbonate production device according to claim 1, characterized in that: The cleaning comprises the following steps: delivering the detergent to the polycarbonate production unit; heating and steaming a polycarbonate production device containing the detergent; After the cooking is completed, the cooked detergent is discharged from the polycarbonate production device.

5. The method for cleaning blockage in a polycarbonate production device according to claim 4, characterized in that: Before and / or during the cooking, the method further includes: connecting the polycarbonate production device containing the detergent to a vacuum system, and evacuating the polycarbonate production device containing the detergent through the vacuum system.

6. The method for cleaning blockages in a polycarbonate production device according to claim 1, wherein the cleaning is repeated; the volume of the detergent during each cleaning accounts for 1 / 3 to 2 / 3 of the total volume remaining in the polycarbonate production device excluding the blockages.

7. The method for cleaning blockage in a polycarbonate production device according to claim 4, characterized in that: The cleaning is repeated; the cooking time for each cleaning is 1 to 3 hours.

8. The method for cleaning blockage in a polycarbonate production device according to claim 4 or 7, characterized in that: The cooking temperature is 90-130°C.

9. The method for cleaning blockage in a polycarbonate production device according to claim 1 or 4, characterized in that: After the cleaning is completed, the method further includes: heating the cleaned polycarbonate production device to remove the volatile alkaline catalyst in the detergent remaining in the polycarbonate production device.

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