A device and method for recycling heavy boiler acidolysis in trioxane production

Abstract

The application provides a device and method for recycling heavy boiling acidolysis in trioxane production, which comprises a main reactor, a pre-reactor, a catalytic rectifying tower, a condenser, a buffer tank, a reflux pump, a discharge pump, a reboiler and a side line pump-off pump, and the method uses solid acid or carbon-based sulfonic acid as a catalyst and heavy boiling produced in trioxane production as a reaction raw material, adopts a catalytic rectification method to generate and preliminarily purify formaldehyde, realizes preliminary separation of formaldehyde and other heavy boiling, the method adopts solid acid catalysis, material separation is simple, corrosion to the material of the reactor and other equipment is small, equipment investment is small, a large amount of acidic waste liquid is not generated, formaldehyde is recycled, production cost is reduced, the amount of sewage treatment is reduced, and the effect of reducing environmental pollution is achieved.

Description

Technical Field

[0001] This invention relates to the field of formaldehyde acid reaction preparation of trioxymethylene technology, specifically to a device and method for acid hydrolysis and recycling of reboilers in trioxymethylene production. Background Technology

[0002] During the preparation of trioxymethylene, the concentration of reboiler residue at the bottom of the reactor gradually increases, leading to a decrease in trioxymethylene recovery rate, increased viscosity of the reaction liquid in the reactor, and a tendency to flood, resulting in insufficient load capacity. Regular drainage or replacement is required, which not only affects production and generates large amounts of waste liquid, increasing material consumption, but also increases the difficulty of wastewater treatment and causes environmental pollution. Returning the reboiler residue to the trioxymethylene reactor can achieve acidolysis of some of the reboiler residue and reduce waste liquid discharge, but it severely affects the normal operation of the reactor. Under solid acid conditions, the reboiler residue discharged from the bottom of the reboiler requires a lower reaction temperature, making it difficult for formic acid to distill off; under sulfuric acid catalysis, a higher reaction temperature is required, and some formic acid distills off. Summary of the Invention

[0003] The technical problem this invention aims to solve is to provide a device and method for the acid hydrolysis and recovery of reboilers in the production of trioxymethylene (TOM). This addresses the environmental pollution caused by wastewater treatment of reboilers generated during TOM preparation, while also offering the benefits of recycling and cost savings. This method provides an approach to the acid hydrolysis and recovery of reboilers in TOM production, significantly reducing wastewater treatment difficulty and promoting emission reduction and energy conservation in actual production. Furthermore, this method provides a device for recovering and treating reboilers generated during TOM preparation. The wastewater produced by this device is easily treated, and formaldehyde can be recovered for continued use in TOM preparation, effectively saving energy and improving efficiency while ensuring safety and environmental protection.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a device for the acid hydrolysis and recovery of reboilers in the production of trioxymethylene, comprising a main reactor, a pre-reactor, a catalytic distillation column, a condenser, a buffer tank, a reflux pump, a discharge pump, a reboiler, and a collection pump. The output ends of the main reactor and the pre-reactor are fixedly connected to the catalytic distillation column. The output end of the pre-reactor is fixedly connected to the buffer tank. The output end of the catalytic distillation column is fixedly connected to the input ends of the pre-reactor and the condenser, respectively. The output end of the condenser is connected to the... The input end of the buffer tank is fixedly connected, the output end of the buffer tank is fixedly connected to the input end of the reflux pump, the output end of the reflux pump is fixedly connected to the catalytic distillation column, the output end of the catalytic distillation column is fixedly connected to the input end of the discharge pump, the output end of the discharge pump and the top of the main reactor are respectively fixedly connected to the input end of the reboiler, the output end of the reboiler is fixedly connected to the catalytic distillation column, the circulation mode of the reboiler is set to forced circulation, and the bottom output end of the catalytic distillation column is fixedly connected to the input end of the collection pump.

[0005] A further improvement of the present invention is that: the pre-reactor is provided with an outer jacket, and the pre-reactor is configured as a fixed-bed reactor, and a built-in catalyst is provided in the pre-reactor, wherein the built-in catalyst is a solid acid catalyst or a carbon-based sulfonic acid.

[0006] A further improvement of the present invention is that: the pre-reactor is provided with an outer jacket, and the pre-reactor is configured as a fixed-bed reactor, and an internal catalyst is provided in the pre-reactor, which is a solid acid catalyst or a carbon-based sulfonic acid.

[0007] A further improvement of the present invention is that the main reactor is made of titanium, the catalytic distillation column is a plate or packed column, and the packing material is a solid acid or carbon-based sulfonic acid.

[0008] A further improvement of the present invention is that a spray pipe is provided at the inlet of the condenser, the cooling medium of the condenser is hot water, and the cooling water of the condenser is a water circulation pump.

[0009] A further improvement of the present invention is that the output end of the pre-reactor is directly connected to the buffer tank via a pipeline.

[0010] A further improvement of the present invention is that: the top output end of the catalytic distillation column is connected to the pre-reactor via a pipeline, and the bottom output end of the catalytic distillation column is directly connected to the extraction pump via a pipeline.

[0011] A further improvement of the present invention is that the output end of the bottom of the catalytic distillation column is connected to a discharge pump through a pipeline to carry the sludge into the reboiler and the main reactor.

[0012] A method for recovering and utilizing reboilers in the production of paraformaldehyde, applied to a paraformaldehyde production reboiler acidolysis recovery and utilization device, includes the following operating steps:

[0013] S1: The reactants are 50-60% trioxymethylene and 40-50% reboiler. The reaction and initial concentration are carried out by catalytic distillation using a catalyst. The reactants are pumped into a pre-reactor to obtain crude formaldehyde reaction solution. The crude reaction solution from the pre-reactor enters the bottom of a catalytic distillation column, in which solid acid or carbon-based sulfonic acid is used as the reaction catalyst. The catalytic distillation column is used in conjunction with a circulating reactor to replace the reaction vessel in the traditional process. The solid acid can withstand a temperature of not less than 130℃. Each layer of solid acid is laid with a thickness of 5-10cm. The reaction pressure should be 0-0.4MPa. The reactor residence time is 10-50min.

[0014] S2: Part of the reboiled material at the bottom of the catalytic distillation column is pumped into the main reactor to obtain formaldehyde solution, and part of it enters the reboiler for forced circulation;

[0015] S3: The catalyst loading method of the catalytic distillation column is to directly place several catalyst sections in the catalytic distillation column, and / or to adopt an external circulation method, so that the bottom liquid of the column passes through the fixed bed reactor containing the catalyst and then returns to the catalytic distillation column. The formaldehyde solution obtained from the external circulation reactor enters the bottom of the synthesis column, and some stable cyclic products are precipitated to the bottom of the synthesis column and pumped out of the system for sewage treatment.

[0016] S4: Part of the gas from the top of the catalytic distillation column enters the condenser, and the condensed water-soluble liquid enters the buffer tank. The condenser is equipped with a water mist spray nozzle, which can effectively enhance gas condensation and, on the other hand, help formaldehyde dissolve in water. The condenser is cooled with hot water at 30-50°C to raise the temperature of the tubes, so as to inhibit formaldehyde from scaling on the metal surface. The other part of the gas enters the pre-reactor, bringing heat to the pre-reactor and keeping the temperature inside the reactor at 98-105°C.

[0017] S5: Water and formaldehyde are produced by the reaction in the catalytic distillation column. The formaldehyde is continuously distilled off at the top of the column and then condensed into liquid by the condenser before entering the buffer tank. At the same time, a portion of the solution in the pre-reactor enters the buffer tank for further cooling. A portion of the formaldehyde solution in the buffer tank enters the subsequent purification or material recycling process, while a portion of the solution is further circulated by the reflux pump.

[0018] A further improvement of the present invention is that, in step S4, another part of the gas enters the pre-reactor, bringing heat to the pre-reactor and maintaining the temperature inside the reactor at 102°C.

[0019] Due to the adoption of the above technical solution, the beneficial effects achieved by this invention are:

[0020] (1) The device and method for acid hydrolysis and recycling of reboilers in the production of trioxymethylene effectively solves the problem that reboilers cannot be utilized and are complicated to process. Solid acid or carbon-based sulfonic acid is used as a catalyst, and the reboilers produced in the production of trioxymethylene are used as reaction raw materials to generate and preliminarily purify formaldehyde by catalytic distillation.

[0021] (2) The device and method for acid hydrolysis and recycling of reboilers in the production of trioxymethylene use solid acid as a catalyst to avoid the addition of sulfuric acid, and the reaction materials have relatively little corrosion to the reaction equipment materials.

[0022] (3) The main reaction tower of the reboiler acid hydrolysis recovery and utilization device and method in the production of trioxymethylene can meet the requirements by using titanium material, and no waste acid is generated in the production process that is difficult to handle. On the other hand, part of the gas in the distillation tower enters the pre-reactor, and part of the solution in the pre-reactor enters the buffer tank, effectively utilizing heat, reducing heat loss, realizing continuous production, and achieving a high degree of automation. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of a device for the acidolysis and recovery of reboilers in the production of trioxymethylene, as proposed in this invention.

[0024] The attached diagram lists the components represented by each number as follows:

[0025] 100. Main reactor; 200. Pre-reactor; 300. Catalytic distillation column; 400. Condenser; 500. Buffer tank; 600. Reflux pump; 700. Feed pump; 800. Reboiler; 900. Outlet pump. Detailed Implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] The present invention will be described in detail with reference to the following embodiments:

[0028] Example 1

[0029] refer to Figure 1 As shown, a device for the acid hydrolysis and recovery of reboilers in the production of paraformaldehyde includes a main reactor 100, a pre-reactor 200, a catalytic distillation column 300, a condenser 400, a buffer tank 500, a reflux pump 600, a discharge pump 700, a reboiler 800, and a collection pump 900. The output ends of the main reactor 100 and the pre-reactor 200 are fixedly connected to the catalytic distillation column 300. The output end of the pre-reactor 200 is fixedly connected to the buffer tank 500. The output end of the catalytic distillation column 300 is fixedly connected to the input ends of the pre-reactor 200 and the condenser 400, respectively. The output end of the condenser 400 is connected to the buffer tank 500. The input terminal of the buffer tank 500 is fixedly connected to the input terminal of the reflux pump 600. The output terminal of the reflux pump 600 is fixedly connected to the catalytic distillation column 300. The output terminal of the catalytic distillation column 300 is fixedly connected to the input terminal of the discharge pump 700. The output terminal of the discharge pump 700 and the top of the main reactor 100 are respectively fixedly connected to the input terminal of the reboiler 800. The output terminal of the reboiler 800 is fixedly connected to the catalytic distillation column 300. The circulation mode of the reboiler 800 is set to forced circulation. The bottom output terminal of the catalytic distillation column 300 is fixedly connected to the input terminal of the collection pump 900.

[0030] The pre-reactor 200 is provided with an outer jacket and is configured as a fixed-bed reactor. The pre-reactor 200 is provided with an internal catalyst, which is a solid acid catalyst or a carbon-based sulfonic acid.

[0031] The pre-reactor 100 is provided with an outer jacket and is configured as a fixed-bed reactor. The pre-reactor 100 is provided with an internal catalyst, which is a solid acid catalyst or a carbon-based sulfonic acid.

[0032] The main reactor 100 is made of titanium, and the catalytic distillation column 300 is a plate or packed column with the packing material being solid acid or carbon-based sulfonic acid.

[0033] A spray pipe is provided at the inlet of the condenser 400, the cooling medium of the condenser 400 is hot water, and the cooling water of the condenser 400 is a water circulation pump.

[0034] The output of the pre-reactor 200 is directly connected to the buffer tank 500 via a pipeline.

[0035] The top output of the catalytic distillation column 300 is connected to the pre-reactor 200 via a pipeline, and the bottom output of the catalytic distillation column 300 is directly connected to the extraction pump 900 via a pipeline.

[0036] The output end of the bottom of the catalytic distillation column 300 is connected to the discharge pump 700 through a pipeline, which is used to carry the sludge into the reboiler 800 and the main reactor 100.

[0037] A method for recovering and utilizing reboilers in the production of paraformaldehyde, applied to a paraformaldehyde production reboiler acidolysis recovery and utilization device, includes the following operating steps:

[0038] S1: The reactants are 50-60% trioxymethylene and 40-50% reboiler. The reaction and initial concentration are carried out by catalytic distillation using a catalyst. The reactants are pumped into a pre-reactor to obtain crude formaldehyde reaction solution. The crude reaction solution from the pre-reactor enters the bottom of a catalytic distillation column, in which solid acid or carbon-based sulfonic acid is used as the reaction catalyst. The catalytic distillation column is used in conjunction with a circulating reactor to replace the reaction vessel in the traditional process. The solid acid can withstand a temperature of not less than 130℃. Each layer of solid acid is laid with a thickness of 5-10cm. The reaction pressure should be 0-0.4MPa. The reactor residence time is 10-50min.

[0039] S2: Part of the reboiled material at the bottom of the catalytic distillation column is pumped into the main reactor 100 to obtain formaldehyde solution, and part of it enters the reboiler 800 for forced circulation;

[0040] S3: The catalyst loading method of the catalytic distillation column 300 is to directly place several catalyst sections in the catalytic distillation column, and / or to adopt an external circulation method, so that the bottom liquid of the column passes through the fixed bed reactor containing the catalyst and then returns to the catalytic distillation column 300. The formaldehyde solution obtained from the external circulation reactor enters the bottom of the synthesis column, and some stable cyclic products are precipitated to the bottom of the synthesis column and pumped out of the system for sewage treatment.

[0041] S4: Part of the gas from the top of the catalytic distillation column 300 enters the condenser 400, and the condensed water-soluble liquid enters the buffer tank 500. The condenser 400 is equipped with a water mist spray nozzle, which can effectively enhance gas condensation and, on the other hand, help formaldehyde dissolve in water. The condenser is cooled with hot water at 30-50℃ to raise the temperature of the tubes, so as to inhibit the scaling of formaldehyde on the metal surface. The other part of the gas enters the pre-reactor 200, which brings heat to the pre-reactor 200 and keeps the temperature inside the reactor at 98-105℃.

[0042] S5: Water and formaldehyde are generated by the reaction in the catalytic distillation column 300. The formaldehyde is continuously distilled off at the top of the column and then condensed into liquid by the condenser 400 before entering the buffer tank 500. At the same time, a portion of the solution in the pre-reactor 200 enters the buffer tank 500 for further cooling. A portion of the formaldehyde solution in the buffer tank 500 enters the subsequent purification or material recycling process, while a portion of the solution is further circulated by the reflux pump 600.

[0043] In step S4, another portion of the gas enters the pre-reactor 200, bringing heat to the pre-reactor 200 and maintaining its internal temperature at 102°C.

[0044] Example 2

[0045] To achieve the above objectives, the present invention provides the following solution: a device for the acid hydrolysis and recovery of reboilers in the production of trioxymethylene, comprising a main reactor 100, a pre-reactor 200, a catalytic distillation column 300, a condenser 400, a buffer tank 500, a reflux pump 600, a discharge pump 700, a reboiler 800, and a collection pump 900. The output ends of the main reactor 100 and the pre-reactor 200 are fixedly connected to the catalytic distillation column 300 via pipes and flanges. The output end of the pre-reactor 200 is fixedly connected to the buffer tank 500 via pipes and flanges. The output end of the catalytic distillation column 300 is fixedly connected to the input ends of the pre-reactor 200 and the condenser 400 via pipes and flanges. The output end of the condenser 400 is fixedly connected to the input end of the buffer tank 500 via pipes and flanges. The output end of the buffer tank 500 is fixedly connected to the input end of the reflux pump 600 via pipes and flanges. The output end of the reflux pump 600 is fixedly connected to the catalytic distillation column 300 via a pipe and a flange. The output end of the catalytic distillation column 300 is fixedly connected to the input end of the discharge pump 700 via a pipe and a flange. The output end of the discharge pump 700 and the top of the main reactor 100 are fixedly connected to the input end of the reboiler 800 via a pipe and a flange. The output end of the reboiler 800 is fixedly connected to the catalytic distillation column 300 via a pipe and a flange. The bottom output end of the catalytic distillation column 300 is fixedly connected to the input end of the extraction pump 900 via a pipe and a flange.

[0046] Preferably, the corrosion of the catalytic distillation column 300 is much lower than that of the combination of formic acid and sulfuric acid. The equipment is made of titanium. The structure of the catalytic distillation column 300 is a plate type and a packed column. The packing material is solid acid carbon-based sulfonic acid.

[0047] Preferably, the pre-reactor 200 is a fixed-bed reactor with a built-in solid acid catalyst, carbon-based sulfonic acid, and an external jacket is provided on the outside of the pre-reactor 200.

[0048] Preferably, the pre-reactor 100 is a fixed-bed reactor with a built-in solid acid catalyst, carbon-based sulfonic acid, and an outer jacket is provided on the outside of the pre-reactor 100.

[0049] Preferably, the reboiler 800 uses forced circulation.

[0050] Preferably, a spray pipe is designed at the inlet of the condenser 400, and hot water is used as the cooling medium of the condenser 400. The cooling water of the condenser 400 is circulated by a water pump through pipes and flanges.

[0051] Preferably, the output end of the pre-reactor 200 is directly connected to the buffer tank 500 via a pipeline, and the top output end of the catalytic distillation column 300 is connected to the pre-reactor 200 via a pipeline, thereby reducing heat consumption.

[0052] Preferably, the bottom output end of the catalytic distillation column 300 is directly connected to the extraction pump 900 via a pipeline, and the bottom stable annular sediment and other sludge are treated for sewage discharge.

[0053] Preferably, the output end of the catalytic distillation column 300 is connected to the discharge pump 700 via a pipeline slightly above the bottom, so as to minimize the introduction of stable annular substances and other sludge into the reboiler 800 and the main reactor 100.

[0054] A method for recovering and utilizing reboilers in the production of paraformaldehyde, applied to a paraformaldehyde production reboiler acidolysis recovery and utilization device, includes the following steps:

[0055] S1: The reactants are 50-60% trioxymethylene and 40-50% reboiler. The reaction and initial concentration are carried out by catalytic distillation using a catalyst. The reactants are pumped into a pre-reactor to obtain crude formaldehyde reaction solution. The crude reaction solution from the pre-reactor enters the bottom of a catalytic distillation column, in which solid acid carbon-based sulfonic acid is used as the reaction catalyst. The catalytic distillation column is used in conjunction with a circulating reactor to replace the reaction vessel in the traditional process. The solid acid can withstand a temperature of not less than 130℃. Each layer of solid acid is laid with a thickness of 5-10cm. The reaction pressure should be 0-0.4MPa. The reactor residence time is 10-50min.

[0056] S2: Part of the reboiled material at the bottom of the catalytic distillation column is pumped into the main reactor 100 to obtain formaldehyde solution, and part of it enters the reboiler 800 for forced circulation;

[0057] S3: The catalyst loading method of the catalytic distillation column 300 is to directly place several catalyst sections in the catalytic distillation column, or to adopt an external circulation method, so that the bottom liquid of the column passes through the fixed bed reactor containing the catalyst and then returns to the catalytic distillation column 300, or both. The formaldehyde solution obtained from the external circulation reactor enters the bottom of the synthesis column, and some stable cyclic products are precipitated to the bottom of the synthesis column and pumped out of the system for sewage treatment.

[0058] S4: Part of the gas from the top of the catalytic distillation column 300 enters the condenser 400, and the condensed water-soluble liquid enters the buffer tank 500. The condenser 400 is equipped with a water mist spray nozzle, which can effectively enhance gas condensation and, on the other hand, help formaldehyde dissolve in water. The condenser is cooled with hot water at 30-50℃, which keeps the tube temperature high and can effectively inhibit formaldehyde from scaling on the metal surface. The other part of the gas enters the pre-reactor 200, which brings heat to the pre-reactor 200 and keeps the temperature inside the reactor at about 102℃.

[0059] S5: Water and formaldehyde are generated by the reaction in the catalytic distillation column 300. The formaldehyde is continuously distilled off at the top of the column and then condensed into liquid by the condenser 400 before entering the buffer tank 500. At the same time, a portion of the solution in the pre-reactor 200 enters the buffer tank 500 for further cooling. A portion of the formaldehyde solution in the buffer tank 500 enters the subsequent purification or material recycling process, while a portion of the solution is further circulated by the reflux pump 600.

[0060] This method for recovering and utilizing reboilers from the production of trioxymethylene effectively solves the problem of unusable and complex treatment of reboilers. It uses a solid acid (carbon-based sulfonic acid) as a catalyst, employing catalytic distillation to generate and initially purify formaldehyde from the reboilers produced during trioxymethylene production. The use of a solid acid as a catalyst avoids the need for sulfuric acid, resulting in less corrosion of the reaction equipment. The main reaction tower can be made of titanium, meeting the requirements. Furthermore, it avoids the generation of difficult-to-treat waste acid during production. On the other hand, a portion of the gas from the distillation tower enters the pre-reactor, and a portion of the solution from the pre-reactor enters the buffer tank, effectively utilizing heat and reducing heat loss. This method achieves continuous production with a high degree of automation.

[0061] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are by no means intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is impossible to exhaustively list all possible implementations here, and any obvious variations or modifications derived therefrom still fall within the scope of protection of this invention.

Claims

1. A device for acid hydrolysis and recovery of reboilers in the production of trioxymethylene, characterized in that: The reactor includes a main reactor (100), a pre-reactor (200), a catalytic distillation column (300), a condenser (400), a buffer tank (500), a reflux pump (600), a discharge pump (700), a reboiler (800), and a collection pump (900). The output ends of the main reactor (100) and the pre-reactor (200) are fixedly connected to the catalytic distillation column (300). The other output end of the pre-reactor (200) is fixedly connected to the buffer tank (500). The output end of the catalytic distillation column (300) is fixedly connected to the input ends of the pre-reactor (200) and the condenser (400), respectively. The output end of the condenser (400) is fixedly connected to the input end of the buffer tank (500). The output end of the buffer tank (500) is fixedly connected to the input end of the reflux pump (600), the output end of the reflux pump (600) is fixedly connected to the catalytic distillation column (300), the other output end of the catalytic distillation column (300) is fixedly connected to the input end of the discharge pump (700), the output end of the discharge pump (700) and the top of the main reactor (100) are respectively fixedly connected to the input end of the reboiler (800), the output end of the reboiler (800) is fixedly connected to the catalytic distillation column (300), the circulation mode of the reboiler (800) is set to forced circulation, and the bottom output end of the catalytic distillation column (300) is fixedly connected to the input end of the extraction pump (900). Both the main reactor (100) and the pre-reactor (200) are equipped with built-in catalysts, which are solid acid catalysts or carbon-based sulfonic acid catalysts.

2. The apparatus for acid hydrolysis and recovery of reboilers in the production of paraformaldehyde according to claim 1, characterized in that: The pre-reactor (200) is provided with an outer jacket, and the pre-reactor (200) is configured as a fixed-bed reactor.

3. The apparatus for acid hydrolysis and recovery of reboilers in the production of paraformaldehyde according to claim 1, characterized in that: The main reactor (100) is made of titanium, the catalytic distillation column (300) is a plate or packed column, and the catalyst used in the catalytic distillation column (300) is a solid acid or carbon-based sulfonic acid.

4. The apparatus for acid hydrolysis and recovery of reboilers in the production of trioxymethylene according to claim 1, characterized in that: A spray pipe is provided at the inlet of the condenser (400), the cold medium of the condenser (400) is hot water, and the cooling water of the condenser (400) is a water circulation pump.

5. The apparatus for acid hydrolysis and recovery of reboilers in the production of trioxymethylene according to claim 1, characterized in that: The output of the pre-reactor (200) is directly connected to the buffer tank (500) via a pipeline.

6. The apparatus for acid hydrolysis and recovery of reboilers in the production of trioxymethylene according to claim 1, characterized in that: The top output of the catalytic distillation column (300) is connected to the pre-reactor (200) via a pipeline, and the bottom output of the catalytic distillation column (300) is directly connected to the extraction pump (900) via a pipeline.

7. The apparatus for acid hydrolysis and recovery of reboilers in the production of paraformaldehyde according to claim 1, characterized in that: The bottom output of the catalytic distillation column (300) is connected to a discharge pump (700) via a pipeline to carry the sludge into the reboiler (800) and the main reactor (100).

8. A method for acid hydrolysis and recovery of reboilers in the production of trioxymethylene, applied to the acid hydrolysis and recovery device for reboilers in the production of trioxymethylene as described in any one of claims 1-7, characterized in that: The following steps are included: S1: The reactants are 50-60% trioxymethylene and 40-50% reboiler. The reaction and initial concentration are carried out by catalytic distillation using a catalyst. The reactants are pumped into a pre-reactor to obtain crude formaldehyde reaction solution. The crude reaction solution from the pre-reactor enters the bottom of a catalytic distillation column, in which solid acid or carbon-based sulfonic acid is used as the reaction catalyst. The catalytic distillation column is used in conjunction with a circulating reactor to replace the reaction vessel in the traditional process. The solid acid can withstand a temperature of not less than 130℃. Each layer of solid acid is laid with a thickness of 5-10cm. The reaction pressure should be 0-0.4MPa. The reactor residence time is 10-50min. S2: A portion of the reboiled material at the bottom of the catalytic distillation column is pumped into the main reactor (100) to obtain formaldehyde solution, and a portion enters the reboiler (800) for forced circulation; S3: The catalyst loading method of the catalytic distillation column (300) is to directly place several catalyst sections in the catalytic distillation column, and / or adopt an external circulation method, so that the bottom liquid of the column passes through the fixed bed reactor containing the catalyst and then returns to the catalytic distillation column (300). The formaldehyde solution obtained from the external circulation reactor enters the bottom of the synthesis column, and some stable cyclic products are precipitated to the bottom of the synthesis column and pumped out of the system for sewage treatment. S4: Part of the gas at the top of the catalytic distillation column (300) enters the condenser (400), and the condensed water-soluble liquid enters the buffer tank (500). The condenser (400) is equipped with a water mist spray nozzle, which can effectively enhance gas condensation and, on the other hand, help formaldehyde dissolve in water. The condenser is cooled with hot water at 30-50°C to raise the temperature of the tubes and thus inhibit formaldehyde from scaling on the metal surface. The other part of the gas enters the pre-reactor (200), which brings heat to the pre-reactor (200) and keeps the temperature inside the reactor at 98-105°C. S5: Water and formaldehyde are generated by the reaction in the catalytic distillation column (300). The formaldehyde is continuously distilled off at the top of the column and then condensed into liquid by the condenser (400) and enters the buffer tank (500). At the same time, a part of the solution in the pre-reactor (200) enters the buffer tank (500) for further cooling. A part of the formaldehyde solution in the buffer tank (500) enters the subsequent purification or material recycling process, and a part of the solution is further circulated by the reflux pump (600).

9. A method for acid hydrolysis and recovery of reboilers in the production of paraformaldehyde according to claim 8, characterized in that: In step S4, another portion of the gas enters the pre-reactor (200), bringing heat to the pre-reactor (200) and maintaining its internal temperature at 102°C.

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