A method for high-efficiency treatment of terephthalic acid oxidation residues and a burning device thereof

Abstract

This invention relates to the field of terephthalic acid oxidation residue technology, specifically a high-efficiency treatment method for terephthalic acid oxidation residue, comprising the following steps: S1. Pretreatment; S2. Separation; S3. Evaporation and concentration; S4. Incineration; S5. Ash dissolution; S6. Filtration; S7. Sodium carbonate recovery; S8. Sodium carbonate recycling; S9. Bromine recovery and utilization; S10. Cobalt-manganese catalyst recovery; S11. Precipitate treatment; S12. Cobalt-manganese catalyst recycling. This application utilizes the waste heat or residual heat from the top of the xylene oxidation unit as a heat source to heat and concentrate the first filtrate. The acetic acid flash evaporator in the crystallizer serves as the heat source for evaporator V3 to evaporate and concentrate sodium carbonate, reducing process energy consumption and improving sodium carbonate recovery efficiency. The incineration unit heats the furnace body through external and internal incineration components, achieving efficient incineration of the material, greatly increasing the material's heating efficiency, and improving incineration efficiency and energy utilization.

Description

Technical Field

[0001] This invention relates to the field of terephthalic acid oxidation residue technology, specifically to a high-efficiency treatment method and incineration device for terephthalic acid oxidation residue. Background Technology

[0002] Terephthalic acid (PTA) is an important organic synthetic monomer in the chemical industry, mainly used in the production of polyethylene terephthalate (PET) and bottle-grade polyester. Currently, China's PTA production capacity has exceeded 50 million tons. To ensure the quality of PTA products, the mother liquor needs to be extracted during the PTA production process and then sent to a thin-film evaporator to recover acetic acid. The distillation residue is discharged as waste, accounting for approximately 0.45-0.6% of the total PTA production. The main components of this residue are oxidation byproducts of organic acids, along with small amounts of cobalt, manganese, heavy metals, and bromides. Furthermore, during PTA manufacturing, alkaline solutions are often used for cleaning to remove blockages from various equipment and pipelines. Other waste materials from leaks, spills, and drips are also discharged into waste collection ponds. These waste residues are also discharged into the PTA oxidation waste residue system. Because these waste residues are complex in composition and their composition and content fluctuate with the high-temperature oxidation process, comprehensive recycling and utilization of the waste residues presents challenges.

[0003] To recover various substances from the residue, steps such as incineration and evaporation concentration are required. Incineration and other processes consume a large amount of energy. If the excess heat energy cannot be utilized, it will result in a significant waste of energy.

[0004] Therefore, there is a need for a high-efficiency treatment method and incineration device for terephthalic acid oxidation residue, which can efficiently recover substances from the terephthalic acid oxidation residue and recover heat during the incineration process to reduce energy waste. Summary of the Invention

[0005] To address the above problems, this invention provides a high-efficiency treatment method for terephthalic acid oxidation residue and its incineration device.

[0006] The technical solution adopted by this invention to solve its technical problem is: a high-efficiency treatment method for terephthalic acid oxidation residue, comprising the following steps:

[0007] S1. Pretreatment: Add the terephthalic acid oxidation residue to the mixing device, then stir and react the sodium carbonate aqueous solution or sodium hydroxide aqueous solution with the sodium carbonate aqueous solution, and adjust the pH of the solution to 7-8, controlling the solid content in the solution to 3-5%;

[0008] S2. Separation: The mixture after pretreatment in step S1 is filtered to obtain solid A and a first filtrate, wherein the solid content in the first filtrate is 3-5%;

[0009] S3. Evaporation and Concentration: The first filtrate obtained in step S2 is added to the multi-effect evaporation system V1. The residual heat at the top of the dehydration tower of the xylene oxidation unit, which is 85°C, is used as a heat source for evaporation and concentration. The solid content of the first filtrate obtained in step S2 is concentrated from 3~5% to 25~40%. Then it is sent to the single-effect evaporation system V2 for evaporation and concentration to 50~70% to obtain a concentrated liquid. The water vapor generated during the evaporation process is recovered after cooling.

[0010] S4. Incineration: The concentrated liquid obtained in step S3 is sent to the incineration device for incineration to obtain ash residue. The high-temperature flue gas generated during the incineration process is treated by the heat exchange part of the incineration device to obtain water vapor with a pressure of 0~9.8 MPa and a temperature of 180~360℃.

[0011] S5. Ash and slag dissolution: Add the ash and slag obtained in step S4 to the dissolution tank, and then add pure water to make the ash and slag concentration reach 15~25% to obtain ash and slag dissolution solution.

[0012] S6. Filtration: The ash residue solution obtained in step S5 is filtered. The filtered solid filter cake is washed with pulping water and sent to a centrifuge to separate solid B and filtrate. The filtrate is pumped into evaporator V3.

[0013] S7. Sodium carbonate recycling: Acetic acid flash vapor from the terephthalic acid crystallizer in the xylene oxidation unit is used as the heat source for evaporator V3. The flash vapor temperature is 85~95℃ and the pressure is -46~-55Kpag. When the sodium carbonate concentration in the salt leg at the bottom of evaporator V3 reaches 28~32%, it is collected by gravity flow and sent to evaporator V4 to further concentrate the sodium carbonate concentration to 58~62%. Then, it is separated by centrifuge to obtain filter cake with a moisture content of 13~17% and bromine-containing mother liquor. The filter cake is directly used to prepare sodium carbonate aqueous solution or dried to obtain solid sodium carbonate product. The water vapor generated during the evaporation process is recovered after cooling.

[0014] S8. Sodium carbonate recycling: Add the evaporated water or pure water condensed by the condenser during the evaporation process in steps S3 and S7 to the filter cake obtained in step S7 to prepare sodium carbonate with a concentration of 20~25%, and return it to step S1 for recycling.

[0015] S9. Bromine recovery and utilization: When the sodium bromide content in the bromine-containing mother liquor in step S7 reaches 30~43%, the bromine-containing mother liquor is transferred to the reaction evaporator. Phosphoric acid or sulfuric acid aqueous solution is added to the reaction evaporator, heated to boiling, and the distillate is collected to obtain crude hydrobromic acid, which is sent to the catalyst device as raw material. When no hydrobromic acid is distilled off, the remaining liquid is sent to the crystallization kettle, cooled or evaporated to crystallize and obtain sodium hydrogen phosphate or sodium sulfate products.

[0016] The molar ratio of bromide ions to phosphoric acid or sulfuric acid is 2:01~1, and the concentration of added phosphoric acid is 40~98% and the concentration of added sulfuric acid is 40~95%.

[0017] S10. Recovery of cobalt-manganese catalyst: Add solid A obtained in step S2 to a mixer, add dilute acetic acid to the mixer, heat to 80℃~boiling, maintain for 30~180min, filter while hot to obtain catalyst filtrate and precipitate C;

[0018] The content of dilute acetic acid is 25-40%, and the molar ratio of cobalt and manganese to acetic acid is 1:2.05-6.0.

[0019] S11. Precipitate treatment: The solid B obtained in step S6 and the precipitate C obtained in step S10 are fed into the reactor, and the hydrobromic acid collected in step S9 or fresh hydrobromic acid and water are added to react. The molar ratio of cobalt manganese to hydrobromic acid is 1:2.2~3.0. When the concentration of cobalt manganese ions in the solution no longer changes or the dissolution is complete, cobalt carbonate and / or manganese carbonate are added to adjust the pH of the solution to 5~6, the solution is stirred and dissolved, and the catalyst filtrate is obtained by filtration.

[0020] S12. Recycling of cobalt-manganese catalyst: The catalyst filtrate obtained in steps S10 and S11 is returned to the catalyst blending system and mixed with fresh catalyst for use.

[0021] As an optimization, in step S1, the mass fraction of the sodium hydroxide aqueous solution is 20-40%, and the concentration of the sodium carbonate aqueous solution is 20-25%.

[0022] When sodium hydroxide and sodium carbonate are used simultaneously, the pH of the solution is first adjusted to 4-5 using an aqueous solution of sodium hydroxide, and then the pH of the solution is adjusted to 7-8 using sodium carbonate.

[0023] As an optimization, in step S11, the molar ratio of cobalt and manganese to hydrobromic acid in both solid B and precipitate C is 1:2.2~3.0.

[0024] As an optimization, the multi-effect evaporation system V1 in step S3 includes a plate falling film evaporator and a forced circulation evaporator;

[0025] The single-effect evaporation system V2 includes two forced circulation evaporators.

[0026] As an optimization, the incineration device in step S4 includes an incineration section and a heat exchange section, and the incineration section and the heat exchange section are connected by a flue gas duct.

[0027] The heat exchange section includes a heat exchange furnace, which has a flue gas passage inside and is filled with cold water on the inner wall of the heat exchange furnace.

[0028] As an optimization, the incineration section includes an incineration furnace, a heated furnace body, and an incineration assembly. The interior of the incineration furnace is provided with two supports, and a support pipe is connected between the two supports. The incineration assembly is fixedly connected to the support pipe.

[0029] At least four support rollers are connected to the outside of the support tube. The four support rollers are arranged in pairs opposite each other on the lower side of both ends of the heating furnace body along its length. A drive motor is connected to the axis of the support rollers. The heating furnace body is coaxially arranged outside the support tube. The outer side of the heating furnace body is in contact with the support rollers. One end of the support tube is connected to a liquid inlet pipe. The concentrated liquid obtained in step S3 enters the support tube through the liquid inlet pipe.

[0030] The middle part of the support tube is connected to a liquid spraying assembly. The incineration assembly includes an external incineration assembly and an internal incineration assembly. The internal incineration assembly is located inside the heated furnace body, and the external incineration assembly is located outside the heated furnace body. The internal incineration assembly and the external incineration assembly are arranged opposite to each other.

[0031] As an optimization, the spraying assembly includes a first spraying plate and a second spraying plate, both of which are arc plates. The first and second spraying plates are coaxially arranged with the heating furnace body and the support pipe. Connecting pipes are provided between the first spraying plate and the support pipe, and between the second spraying plate and the support pipe. Spraying holes are densely provided on the side of the first spraying plate opposite to the inner side of the heating furnace body and on the side of the second spraying plate opposite to the inner side of the heating furnace body.

[0032] As an optimization, the internal combustion assembly includes two internal flame-spraying arms. The length direction of the internal flame-spraying arms is parallel to the length direction of the support tube. A plurality of first flame-spraying nozzles are evenly provided on the side of the internal flame-spraying arm opposite to the inner side of the heated furnace body. The internal flame-spraying arm is located between the first liquid spraying plate and the second liquid spraying plate.

[0033] The external incineration assembly includes two external flame-spraying arms, and a number of second flame-spraying nozzles are provided on the side of the external flame-spraying arms opposite to the heated furnace body.

[0034] As an optimization, the upper part of the heating furnace body is provided with an arc-shaped receiving plate, and a receiving cavity is formed between the receiving plate and the heating furnace body. A scraping device is provided inside the receiving cavity, and the scraping device contacts the inner wall of the heating furnace body. A spiral conveying paddle is provided inside the receiving cavity. Both ends of the receiving plate are in contact with the inner side of the heating furnace body. The outer end of the receiving plate passes through the incineration furnace and is located on the outer side of the incineration furnace.

[0035] One end of the support pipe is connected to a support frame, and one end of the receiving plate, the scraping device, and the screw conveyor are connected to the support frame. The support frame provides support for the receiving plate, the incineration assembly, the liquid spraying assembly, and the scraping device.

[0036] As an optimization, the scraping device includes a scraping motor, a connecting shaft, and several scraping blades. The scraping blades are arranged along the length of the connecting shaft, and the length of the scraping blades is equal to the length of the heating furnace body. The end of the scraping blade away from the connecting shaft contacts the inner surface of the heating furnace body. The scraping motor is fixedly connected to the support frame, and the output shaft of the scraping motor is coaxially fixedly connected to the connecting shaft. The scraping motor and the connecting shaft drive the scraping blades to rotate, and the scraping blades scrape off the ash and slag produced by combustion on the inner wall of the heating furnace body, which falls into the receiving plate.

[0037] The receiving plate is arc-shaped, curving towards the inner side of the furnace body. It includes a receiving section and an auxiliary plate, with a spring shaft connecting the auxiliary plate and the receiving section. The outer end of the auxiliary plate contacts the inner side of the furnace body. The auxiliary plate rotates towards the side closest to the scraping device, and the furnace body rotates in the same direction. Ash and slag from the inner wall of the furnace body enter the upper part of the receiving plate through the auxiliary plate. Under pressure, the auxiliary plate rotates towards the receiving section, allowing the ash and slag to pass through the auxiliary plate and enter the receiving cavity.

[0038] The beneficial effects of this solution are that it provides a highly efficient method for treating terephthalic acid oxidation residue, which has the following advantages:

[0039] The system utilizes the waste heat or residual heat from the top of the xylene oxidation unit as a heat source to heat and concentrate the first filtrate, and uses the acetic acid flash vapor in the crystallizer as a heat source for evaporator V3 to evaporate and concentrate sodium carbonate, thereby reducing energy consumption in the residue treatment process.

[0040] An incineration device is provided, in which a heated furnace body is set inside the incineration furnace. Material is sprayed onto the inner wall of the heated furnace body through a liquid spraying assembly. The heated furnace body is heated by external and internal incineration assemblies, and the material is incinerated efficiently, which greatly increases the heating efficiency of the material, improves the incineration efficiency and energy utilization, and realizes efficient heat exchange of the heat generated by incineration.

[0041] The recovery and recycling of cobalt, manganese, and bromine catalysts in terephthalic acid oxidation residues has been achieved.

[0042] The water generated during the treatment process is recycled, with no wastewater discharge; fifth, the residue treatment process is green and energy-saving, with no waste discharge. Attached Figure Description

[0043] Appendix Figure 1 This is a schematic diagram of the back axis of the present invention.

[0044] Appendix Figure 2 This is an isometric view of the present invention.

[0045] Appendix Figure 3This is an isometric view of the connection structure between the heated furnace body and the incineration assembly of the present invention.

[0046] Appendix Figure 4 This is a schematic diagram of the back axis of the connection structure between the heated furnace body and the incineration assembly of the present invention.

[0047] Appendix Figure 5 Appendix to this invention Figure 3 A magnified structural diagram of part A.

[0048] Appendix Figure 6 This is a front view schematic diagram of the connection structure between the heated furnace body and the incineration component of the present invention.

[0049] Appendix Figure 7 Appendix to this invention Figure 6 A schematic diagram of the AA cross-section structure.

[0050] Appendix Figure 8 Appendix to this invention Figure 7 A magnified structural diagram of part B.

[0051] The components include: 1. Incineration furnace, 2. Heat exchange section, 3. Heated furnace body, 4. Support, 5. Support pipe, 6. Support roller, 7. Liquid inlet pipe, 8. First spray plate, 9. Second spray plate, 10. Spray hole, 11. Internal flame-spraying arm, 12. External flame-spraying arm, 13. Material receiving plate, 14. Spiral conveyor, 15. Scraper motor, 16. Scraper blade, and 17. Auxiliary plate. Detailed Implementation

[0052] Example 1:

[0053] A high-efficiency treatment method for terephthalic acid oxidation residue includes the following steps:

[0054] S1. Pretreatment: Add the terephthalic acid oxidation residue to the mixing device, then add sodium carbonate aqueous solution and stir to react, adjust the pH of the solution to 7, and control the solid content of the solution to 3%;

[0055] The concentration of the sodium carbonate aqueous solution is 20%;

[0056] S2. Separation: The mixture after pretreatment in step S1 is filtered to obtain solid A and a first filtrate, wherein the solid content of the first filtrate is 3%;

[0057] S3. Evaporation and Concentration: The first filtrate obtained in step S2 is added to the multi-effect evaporation system V1. The residual heat at the top of the dehydration tower of the xylene oxidation unit, which is 85°C, is used as a heat source for evaporation and concentration. The solid content of the first filtrate obtained in step S2 is concentrated from 3% to 25%. Then it is sent to the single-effect evaporation system V2 for evaporation and concentration to 50% to obtain a concentrated liquid. The water vapor generated during the evaporation process is recovered after cooling.

[0058] The multi-effect evaporation system V1 includes one plate falling film evaporator and one forced circulation evaporator; the single-effect evaporation system V2 includes two forced circulation evaporators.

[0059] S4. Incineration: The concentrated liquid obtained in step S3 is sent to the incineration device for incineration to obtain ash residue. The high-temperature flue gas generated during the incineration process is treated by the heat exchange section 2 of the incineration device to obtain 0.2 Pa, 180 °C water vapor.

[0060] The incineration device includes an incineration section and a heat exchange section 2, and the incineration section and the heat exchange section 2 are connected by a flue gas pipe.

[0061] S5. Ash and slag dissolution: Add the ash and slag obtained in step S4 to the dissolution tank, and then add pure water to make the ash and slag concentration reach 15% to obtain the ash and slag dissolution solution.

[0062] S6. Filtration: The ash residue solution obtained in step S5 is filtered. The filtered solid filter cake is washed with pulping water and sent to a centrifuge to separate solid B and filtrate. The filtrate is pumped into evaporator V3.

[0063] S7. Sodium carbonate recovery: Acetic acid flash vapor from the terephthalic acid crystallizer in the xylene oxidation unit is used as the heat source for evaporator V3. The flash vapor temperature is 85℃ and the pressure is -46~Kpag. When the sodium carbonate concentration in the salt leg at the bottom of evaporator V3 reaches 28%, it is collected by gravity flow and sent to evaporator V4 to further concentrate the sodium carbonate concentration to 58%. Then, it is separated by centrifuge to obtain a filter cake with a moisture content of 13% and a bromine-containing mother liquor. The filter cake is directly used for drying to obtain solid sodium carbonate product. The water vapor generated during the evaporation process is recovered after cooling.

[0064] S8. Sodium carbonate recycling: Add the evaporated water condensed by the condenser during the evaporation process in steps S3 and S7 to the filter cake obtained in step S7 to prepare 20% sodium carbonate, and return it to step S1 for recycling.

[0065] S9. Bromine recovery and utilization: When the sodium bromide content in the bromine-containing mother liquor in step S7 reaches 30%, the bromine-containing mother liquor is transferred to the reaction evaporator. Phosphoric acid aqueous solution is added to the reaction evaporator, heated to boiling, and the distillate is collected to obtain crude hydrobromic acid, which is sent to the catalyst device as raw material. When no hydrobromic acid is distilled off, the remaining liquid is sent to the crystallization kettle, cooled or evaporated to crystallize sodium hydrogen phosphate.

[0066] The molar ratio of bromide ions to phosphoric acid is 2:1.01, and the concentration of added phosphoric acid is 40%.

[0067] S10. Recovery of cobalt-manganese catalyst: Add solid A obtained in step S2 to a mixer, add dilute acetic acid to the mixer, heat to boiling, maintain for 30 minutes, filter while hot to obtain catalyst filtrate and precipitate C;

[0068] The content of dilute acetic acid is 25%, and the molar ratio of cobalt and manganese to acetic acid is 1:2.05.

[0069] S11. Precipitate treatment: The solid B obtained in step S6 and the precipitate C obtained in step S10 are sent into the reactor, and the hydrobromic acid and water collected in step S9 are added to react. The molar ratio of cobalt manganese to hydrobromic acid is 1:2.2. When the concentration of cobalt manganese ions in the solution no longer changes, cobalt carbonate is added, stirred and dissolved, the pH of the solution is adjusted to 5, and the catalyst filtrate is obtained by filtration.

[0070] In step S11, the molar ratio of cobalt and manganese to hydrobromic acid in both solid B and precipitate C is 1:2.2.

[0071] S12. Recycling of cobalt-manganese catalyst: The catalyst filtrate obtained in steps S10 and S11 is returned to the catalyst blending system and mixed with fresh catalyst for use.

[0072] Example 2:

[0073] A high-efficiency treatment method for terephthalic acid oxidation residue includes the following steps:

[0074] S1. Pretreatment: Add the terephthalic acid oxidation residue to the mixing device, then add sodium hydroxide aqueous solution and sodium carbonate aqueous solution, stir and react, adjust the pH of the solution to 8, and control the solid content of the solution to 5%;

[0075] The sodium hydroxide aqueous solution has a mass fraction of 40%, the sodium carbonate aqueous solution has a concentration of 22%, the pH value of the solution is adjusted to 4 using sodium hydroxide, and then the pH value of the solution is adjusted to 8 using sodium carbonate.

[0076] S2. Separation: The mixture after pretreatment in step S1 is filtered to obtain solid A and a first filtrate, wherein the solid content of the first filtrate is 5%;

[0077] S3. Evaporation and Concentration: The first filtrate obtained in step S2 is added to the multi-effect evaporation system V1. The waste heat at the top of the dehydration tower of the xylene oxidation unit, which is 85°C, is used as a heat source for evaporation and concentration. The solid content of the first filtrate obtained in step S2 is concentrated from 5% to 40%. Then it is sent to the single-effect evaporation system V2 for evaporation and concentration to 70% to obtain a concentrated liquid. The water vapor generated during the evaporation process is recovered after cooling.

[0078] The multi-effect evaporation system V1 includes one plate falling film evaporator and one forced circulation evaporator; the single-effect evaporation system V2 includes two forced circulation evaporators.

[0079] S4. Incineration: The concentrated liquid obtained in step S3 is sent to the incineration device for incineration to obtain ash residue. The high-temperature flue gas generated during the incineration process is treated by the heat exchange section 2 of the incineration device to obtain water vapor at 9.8 MPa and 360°C.

[0080] The incineration device includes an incineration section and a heat exchange section 2, and the incineration section and the heat exchange section 2 are connected by a flue gas pipe.

[0081] S5. Ash and slag dissolution: Add the ash and slag obtained in step S4 to the dissolution tank, and then add pure water to make the ash and slag concentration reach 25% to obtain the ash and slag dissolution solution.

[0082] S6. Filtration: The ash residue solution obtained in step S5 is filtered. The filtered solid filter cake is washed with pulping water and sent to a centrifuge to separate solid B and filtrate. The filtrate is pumped into evaporator V3.

[0083] S7. Sodium carbonate recovery: Acetic acid flash vapor from the terephthalic acid crystallizer in the xylene oxidation unit is used as the heat source for evaporator V3. The flash vapor temperature is 95℃ and the pressure is -55Kpag. When the sodium carbonate concentration in the salt leg at the bottom of evaporator V3 reaches 32%, it is collected by gravity flow and sent to evaporator V4 to further concentrate the sodium carbonate concentration to 62%. Then, it is separated by centrifuge to obtain a filter cake with a moisture content of 17% and a bromine-containing mother liquor. The filter cake is directly used to prepare sodium carbonate aqueous solution. The water vapor generated during the evaporation process is recovered after cooling.

[0084] S8. Sodium carbonate recycling: Add pure water to the filter cake obtained in step S7 to prepare 25% sodium carbonate, and return to step S1 for recycling;

[0085] S9. Bromine recovery and utilization: When the sodium bromide content in the bromine-containing mother liquor in step S7 reaches 43%, the bromine-containing mother liquor is transferred to the reaction evaporator. Sulfuric acid aqueous solution is added to the reaction evaporator, heated to boiling, and the distillate is collected to obtain crude hydrobromic acid, which is sent to the catalyst device as raw material. When no hydrobromic acid is distilled off, the remaining liquid is sent to the crystallization kettle, cooled or evaporated to crystallize and obtain sodium phosphate sulfate product.

[0086] The molar ratio of bromide ions to sulfuric acid is 2:1.1, and the concentration of added phosphoric acid is 98% and the concentration of added sulfuric acid is 95%.

[0087] S10. Recovery of cobalt-manganese catalyst: Add solid A obtained in step S2 to a mixer, add dilute acetic acid to the mixer, heat to 80°C, maintain for 180 min, filter while hot to obtain catalyst filtrate and precipitate C;

[0088] The content of dilute acetic acid is 40%, and the molar ratio of cobalt and manganese to acetic acid is 1:6.0.

[0089] S11. Precipitate treatment: The solid B obtained in step S6 and the precipitate C obtained in step S10 are fed into the reactor, and fresh hydrobromic acid and water are added to react. The molar ratio of cobalt manganese to hydrobromic acid is 1:3.0. When the concentration of cobalt manganese ions in the solution no longer changes, cobalt carbonate is added. Cobalt carbonate and manganese carbonate are first mixed in a molar ratio of 2:1 before being added. The mixture is stirred to dissolve and then filtered to obtain the catalyst filtrate.

[0090] In step S11, the molar ratio of cobalt and manganese to hydrobromic acid in both solid B and precipitate C is 1:3.0;

[0091] S12. Recycling of cobalt-manganese catalyst: The catalyst filtrate obtained in steps S10 and S11 is returned to the catalyst blending system and mixed with fresh catalyst for use.

[0092] Example 3:

[0093] A high-efficiency treatment method for terephthalic acid oxidation residue includes the following steps:

[0094] S1. Pretreatment: Add the terephthalic acid oxidation residue to the mixing device, then add sodium carbonate aqueous solution and stir to react. Adjust the pH of the solution to 7.5 and control the solid content in the solution to 4%.

[0095] The concentration of the sodium carbonate aqueous solution is 25%;

[0096] S2. Separation: The mixture after pretreatment in step S1 is filtered to obtain solid A and a first filtrate, wherein the solid content of the first filtrate is 4%;

[0097] S3. Evaporation and Concentration: The first filtrate obtained in step S2 is added to the multi-effect evaporation system V1. The residual heat at the top of the dehydration tower of the xylene oxidation unit, which is 85°C, is used as a heat source for evaporation and concentration. The solid content of the first filtrate obtained in step S2 is concentrated from 4% to 33%. Then it is sent to the single-effect evaporation system V2 for evaporation and concentration to 60% to obtain a concentrated liquid. The water vapor generated during the evaporation process is recovered after cooling.

[0098] The multi-effect evaporation system V1 includes one plate falling film evaporator and one forced circulation evaporator; the single-effect evaporation system V2 includes two forced circulation evaporators.

[0099] S4. Incineration: The concentrated liquid obtained in step S3 is sent to the incineration device for incineration to obtain ash residue. The high-temperature flue gas generated during the incineration process is treated by the heat exchange section 2 of the incineration device to obtain 5.0 MPa, 270℃ water vapor.

[0100] The incineration device includes an incineration section and a heat exchange section 2, and the incineration section and the heat exchange section 2 are connected by a flue gas pipe.

[0101] S5. Ash and slag dissolution: Add the ash and slag obtained in step S4 to the dissolution tank, and then add pure water to make the ash and slag concentration reach 20% to obtain the ash and slag dissolution solution.

[0102] S6. Filtration: The ash residue solution obtained in step S5 is filtered. The filtered solid filter cake is washed with pulping water and sent to a centrifuge to separate solid B and filtrate. The filtrate is pumped into evaporator V3.

[0103] S7. Sodium carbonate recovery: Acetic acid flash vapor from the terephthalic acid crystallizer in the xylene oxidation unit is used as the heat source for evaporator V3. The flash vapor temperature is 90℃ and the pressure is -50Kpag. When the sodium carbonate concentration in the salt leg at the bottom of evaporator V3 reaches 30%, it is collected by gravity flow and sent to evaporator V4 to further concentrate the sodium carbonate concentration to 60%. Then, it is separated by centrifuge to obtain a filter cake with a moisture content of 15% and a bromine-containing mother liquor. The filter cake is directly used to prepare sodium carbonate aqueous solution. The water vapor generated during the evaporation process is recovered after cooling.

[0104] S8. Sodium carbonate recycling: Add the evaporated water condensed by the condenser during the evaporation process in steps S3 and S7 to the filter cake obtained in step S7 to prepare sodium carbonate with a concentration of 23%, and return it to step S1 for recycling.

[0105] S9. Bromine recovery and utilization: When the sodium bromide content in the bromine-containing mother liquor in step S7 reaches 36%, the bromine-containing mother liquor is transferred to the reaction evaporator. Phosphoric acid aqueous solution is added to the reaction evaporator, heated to boiling, and the distillate is collected to obtain crude hydrobromic acid, which is sent to the catalyst device as raw material. When no hydrobromic acid is distilled off, the remaining liquid is sent to the crystallization kettle, cooled or evaporated to crystallize and obtain sodium hydrogen phosphate or sodium sulfate products.

[0106] The molar ratio of bromide ions to phosphoric acid is 2:1.05, and the concentration of added phosphoric acid is 70%.

[0107] S10. Recovery of cobalt-manganese catalyst: Add solid A obtained in step S2 to a mixer, add dilute acetic acid to the mixer, heat to 90°C, maintain for 105 min, filter while hot to obtain catalyst filtrate and precipitate C;

[0108] The content of dilute acetic acid is 25-40%, and the molar ratio of cobalt and manganese to acetic acid is 1:4.05.

[0109] S11. Precipitate treatment: The solid B obtained in step S6 and the precipitate C obtained in step S10 are fed into the reactor, and the hydrobromic acid and water collected in step S9 are added to react. The molar ratio of cobalt and manganese to hydrobromic acid is 1:2.6. When the cobalt and manganese in the solution are completely dissolved, manganese carbonate is added, stirred and dissolved, the pH of the solution is adjusted to 5.5, and the catalyst filtrate is obtained by filtration.

[0110] In step S11, the molar ratio of cobalt and manganese to hydrobromic acid in both solid B and precipitate C is 1:2.6.

[0111] S12. Recycling of cobalt-manganese catalyst: The catalyst filtrate obtained in steps S10 and S11 is returned to the catalyst blending system and mixed with fresh catalyst for use.

[0112] This solution also includes a controller, the location of which is set by the operator according to the actual situation. The controller is used to control the electrical components used in this solution, including but not limited to sensors, motors, telescopic rods, water pumps, solenoid valves, heating wires, heat pumps, displays, computer input devices, switches, communication devices, lights, speakers, and microphones. The controller is an Intel processor, AMD processor, PLC controller, ARM processor, or microcontroller. It is used in conjunction with a motherboard, memory modules, storage media, and power supply, which is AC power or a lithium battery. When a display screen is provided, a graphics card is also included. For the operating principle of the controller, please refer to "Principles of Automatic Control," "Microcontroller Principles and Application Simulation Cases," and "Sensor Principles and Applications" published by Tsinghua University Press. Other books in this field can also be consulted. Other automation control and electrical components not mentioned are knowledge well known to those skilled in the art and will not be described further here.

[0113] The heat exchange section 2 includes a heat exchange furnace, which has a flue gas passage inside and is filled with cold water on the inner wall of the heat exchange furnace.

[0114] like Figure 1 , 3 As shown, the incineration section includes an incineration furnace 1, a heated furnace body 3, and an incineration assembly. The interior of the incineration furnace 1 is provided with two supports 4, and a support pipe 5 is connected between the two supports 4. The incineration assembly is fixedly connected to the support pipe 5.

[0115] like Figure 3As shown, at least four support rollers 6 are connected to the outside of the support tube 5. The four support rollers 6 are arranged in pairs opposite each other on the lower side of both ends of the heating furnace body 3 in the length direction. A drive motor is connected to the axis of the support rollers 6. The heating furnace body 3 is coaxially arranged outside the support tube 5. The outer side of the heating furnace body 3 is in contact with the support rollers 6. One end of the support tube 5 is connected to a liquid inlet pipe 7. The concentrated liquid obtained in step S3 enters the support tube 5 through the liquid inlet pipe 7.

[0116] like Figure 3 As shown, the middle part of the support pipe 5 is connected to a liquid spraying assembly. The incineration assembly includes an external incineration assembly and an internal incineration assembly. The internal incineration assembly is located inside the heated furnace body 3, and the external incineration assembly is located outside the heated furnace body 3. The internal incineration assembly and the external incineration assembly are arranged opposite to each other.

[0117] like Figure 7 As shown, the spraying assembly includes a first spraying plate 8 and a second spraying plate 9. Both the first spraying plate 8 and the second spraying plate 9 are arc plates. The first spraying plate 8 and the second spraying plate 9 are coaxially arranged with the heating furnace body 3 and the support pipe 5. Connecting pipes are provided between the first spraying plate 8 and the support pipe 5, and between the second spraying plate 9 and the support pipe 5. Spraying holes 10 are densely provided on the side of the first spraying plate 8 opposite to the inner side of the heating furnace body 3 and on the side of the second spraying plate 9 opposite to the inner side of the heating furnace body 3.

[0118] like Figure 7 As shown, the internal combustion assembly includes two internal flame-spraying arms 11. The length direction of the internal flame-spraying arms 11 is parallel to the length direction of the support tube 5. Several first flame-spraying nozzles are evenly provided on the side of the internal flame-spraying arms 11 opposite to the inner side of the heated furnace body 3. The internal flame-spraying arms 11 are located between the first liquid spraying plate 8 and the second liquid spraying plate 9.

[0119] like Figure 7 As shown, the external incineration assembly includes two external flame-spraying arms 12, and a plurality of second flame-spraying nozzles are provided on the side of the external flame-spraying arms 12 opposite to the heated furnace body 3.

[0120] like Figure 7 As shown, the upper part of the heating furnace body 3 is provided with an arc-shaped receiving plate 13, and a receiving cavity is formed between the receiving plate 13 and the heating furnace body 3. A scraping device is provided inside the receiving cavity, and the scraping device is in contact with the inner wall of the heating furnace body 3. A spiral conveying paddle 14 is provided inside the receiving cavity. Both ends of the receiving plate 13 are in contact with the inner side of the heating furnace body 3. The outer end of the receiving plate 13 passes through the incineration furnace chamber 1 and is located on the outer side of the incineration furnace chamber 1.

[0121] like Figure 7As shown, one end of the support pipe 5 is connected to a support frame, and one end of the receiving plate 13, the scraping device, and the spiral conveyor 14 are connected to the support frame.

[0122] like Figure 6 , 7 As shown, the scraping device includes a scraping motor 15, a connecting shaft, and several scraping blades 16. The scraping blades 16 are arranged along the length of the connecting shaft, and the length of the scraping blades 16 is equal to the length of the heating furnace body 3. The end of the scraping blade 16 away from the connecting shaft contacts the inner surface of the heating furnace body 3. The scraping motor 15 is fixedly connected to the support frame, and the output shaft of the scraping motor 15 is coaxially fixedly connected to the connecting shaft. The scraping motor 15 and the connecting shaft drive the scraping blades 16 to rotate, and the scraping blades 16 scrape off the ash and slag produced by combustion on the inner wall of the heating furnace body 3, which falls into the receiving plate 13.

[0123] like Figure 6 , 7 As shown, the receiving plate 13 is arc-shaped and bends towards the inner side of the heating furnace body 3. The receiving plate 13 includes a receiving section and an auxiliary plate 17. A spring shaft connects the auxiliary plate 17 to the receiving section, and the outer end of the auxiliary plate 17 contacts the inner side of the heating furnace body 3. The auxiliary plate 17 rotates towards the side closest to the scraping device, and the rotation direction of the heating furnace body 3 is the same as the rotation direction of the auxiliary plate 17. The ash and slag on the inner wall of the heating furnace body 3 enter the upper side of the receiving plate 13 through the auxiliary plate 17. Under the action of extrusion pressure, the auxiliary plate 17 rotates towards the receiving section, allowing the ash and slag to pass through the auxiliary plate 17 and enter the receiving cavity.

[0124] How to use:

[0125] In actual use, the concentrated liquid obtained in step S3 is injected into the support tube 5 through the inlet pipe 7.

[0126] The concentrated liquid is sprayed onto the inner side of the heated furnace body 3 through the support pipe 5, the first spray plate 8, and the second spray plate 9.

[0127] One end of the external flame-spraying arm 12 is connected to one end of the internal flame-spraying arm 11. Both the external flame-spraying arm 12 and the internal flame-spraying arm 11 have through cavities. The cavities are filled with combustible gas. The combustible gas is sprayed out through the first and second flame-spraying nozzles. The incinerator 1 has a built-in ignition device. The fuel sprayed out through the first and second flame-spraying nozzles of the ignition device is ignited to burn the concentrate.

[0128] At the same time, the support roller 6 is driven to rotate by the drive motor, and the support roller 6 drives the heated furnace body 3 to rotate, so that the concentrate can come into full contact with the flame.

[0129] The ash residue after incineration adheres to the inner wall of the heated furnace body 3. When the ash residue passes through the auxiliary plate 17, the ash residue pushes the auxiliary plate 17 to move towards the upper side of the receiving section.

[0130] The scraper motor 15 drives the connecting shaft to rotate, and scrapes the ash and slag on the inner wall of the heated furnace body 3 through the scraper plate, so that the ash and slag fall onto the upper side of the receiving plate 13.

[0131] One end of the spiral conveyor 14 is connected to a conveyor motor, which drives the spiral conveyor 14 to convey the ash and slag, so that the ash and slag are discharged from the heated furnace body 3.

[0132] The flue gas generated by combustion is discharged into the flue gas passage of heat exchange section 2 through the flue gas pipe. The heat in the flue gas is recovered by the cold water in the inner wall of the heat exchange furnace, reducing energy waste.

[0133] The above-described specific embodiments are merely specific examples of the present invention. The patent protection scope of the present invention includes, but is not limited to, the product form and style of the above-described specific embodiments. Any efficient treatment method and incineration device for terephthalic acid oxidation residue that conforms to the claims of the present invention, and any appropriate changes or modifications made thereto by those skilled in the art, shall fall within the patent protection scope of the present invention.

Claims

1. A method for high performance treatment of terephthalic acid oxidation residue, characterized by: Comprising the following steps: S1. Pretreatment: the terephthalic acid oxidation residue is added to a mixing device, then an aqueous sodium carbonate solution or an aqueous sodium hydroxide solution and an aqueous sodium carbonate solution are added for stirring reaction, and the pH value of the solution is adjusted to 7-8, and the solid content in the solution is controlled to be 3-5%; S2. Separation: the mixture after pretreatment in step S1 is filtered to obtain solid A and a first filtrate, and the solid content in the first filtrate is 3-5%; S3. Evaporation concentration: the first filtrate obtained in step S2 is added to a multi-effect evaporation system V1, and the waste heat of the xylene oxidation device with a top tower temperature of 85 DEG C is used as a heat source for evaporation concentration, and the solid content of the first filtrate obtained in step S2 is concentrated from 3-5% to 25-40%, and then sent to a single-effect evaporation system V2 for evaporation concentration to 50-70% to obtain a concentrated solution, and the water vapor generated in the evaporation process is recovered after cooling; S4. Incineration: the concentrated solution obtained in step S3 is sent to an incineration device for incineration to obtain an ash residue, and the high-temperature flue gas generated in the incineration process is treated by the heat exchange part (2) of the incineration device to obtain 1.0-9.8 MPa, 180-360 DEG C water vapor; S5. Ash residue dissolution: the ash residue obtained in step S4 is added to a dissolving tank, and then pure water is added to make the ash residue concentration reach 15-25% to obtain an ash residue dissolution solution; S6. Filtration: the ash residue dissolution solution obtained in step S5 is filtered, the filtered solid cake is sent to a centrifuge for separation to obtain solid B and a filtrate, and the filtrate is pumped into an evaporator V3; S7. Sodium carbonate recovery: the acetic acid flash gas of the terephthalic acid crystallizer in the xylene oxidation device is used as the heat source of the evaporator V3, the flash gas has a temperature of 85-95 DEG C and a pressure of -55 to -46 kPag, when the sodium carbonate concentration in the salt leg at the bottom of the evaporator V3 reaches 28-32%, it is collected by gravity flow and sent to an evaporator V4 for further concentration of the sodium carbonate concentration to 58-62%, and then separated by a centrifuge to obtain a filter cake with a moisture content of 13-17% and a bromine-containing mother liquor, the filter cake is directly used for preparing an aqueous sodium carbonate solution or dried to obtain a solid sodium carbonate product, and the water vapor generated in the evaporation process is recovered after cooling; S8. Sodium carbonate recycling: the filter cake obtained in step S7 is added with the evaporation water condensed by a condenser in the evaporation processes in steps S3 and S7 or pure water to prepare a 20-25% concentration sodium carbonate solution, which is returned to step S1 for recycling; S9. Bromine recovery and utilization: when the sodium bromide content in the bromine-containing mother liquor in step S7 reaches 30-43%, the bromine-containing mother liquor is transferred into a reaction evaporator, an aqueous phosphoric acid or sulfuric acid solution is added to the reaction evaporator, heated to boiling, and the collected fraction is a crude hydrobromic acid which is sent to a catalyst device as a raw material, when no hydrobromic acid is evaporated, the remaining liquid is sent to a crystallization kettle, and sodium hydrogen phosphate or sodium sulfate products are obtained by cooling or evaporation crystallization; The molar ratio of bromide ions to phosphoric acid or sulfuric acid is 2:1.01-1.1, the concentration of the added phosphoric acid is 40-98%, and the concentration of the added sulfuric acid is 40-95%; S10. Recovery of cobalt-manganese catalyst: the solid A obtained in step S2 is added into a mixer, dilute acetic acid is added into the mixer, heated to 80℃-boiling, kept for 30-180min, filtered while hot, to obtain catalyst filtrate and precipitate C; wherein the content of dilute acetic acid is 25-40%, the molar ratio of cobalt-manganese to acetic acid is 1:2.05-6.0; S11. Precipitate treatment: the solid B obtained in step S6 and the precipitate C obtained in step S10 are sent into a reactor, hydrobromic acid collected in step S9 or fresh hydrobromic acid, water are added for reaction, wherein the molar ratio of cobalt-manganese to hydrobromic acid is 1:2.2-3.0, when the concentration of cobalt-manganese ions in the solution no longer changes or the dissolution is completed, cobalt carbonate or / and manganese carbonate is added to adjust the pH value of the solution to 5-6, stirred and dissolved, filtered to obtain catalyst filtrate; S12. Recycling of cobalt-manganese catalyst: the catalyst filtrate obtained in steps S10, S11 is returned to the catalyst preparation system and used together with fresh catalyst.

2. The method for high efficiency treatment of terephthalic acid oxidation residue according to claim 1, characterized in that: In step S1, the mass fraction of the aqueous sodium hydroxide solution is 20-40%, the concentration of the aqueous sodium carbonate solution is 20-25%; when sodium hydroxide and sodium carbonate are used at the same time, the aqueous sodium hydroxide solution is used first to adjust the pH value of the solution to 4-5, and then the sodium carbonate is used to adjust the pH value of the solution to 7-8.

3. The method for high efficiency treatment of terephthalic acid oxidation residue according to claim 1, characterized in that: In step S11, the molar ratio of cobalt-manganese in solid B and precipitate C to hydrobromic acid is 1:2.2-3.

0.

4. The method for high efficiency treatment of terephthalic acid oxidation residue according to claim 1, characterized in that: The multiple-effect evaporation system V1 in step S3 comprises a plate falling film evaporator and a forced circulation evaporator; The single-effect evaporation system V2 comprises two forced circulation evaporators.

5. The method for treating terephthalic acid oxidation residue according to any one of claims 1 to 4, characterized in that: The incineration device in step S4 comprises an incineration part and a heat exchange part (2), and the incineration part is connected with a flue gas pipeline.

6. The method for high efficiency treatment of terephthalic acid oxidation residue according to claim 5, characterized in that: The incineration part comprises an incineration hearth (1), a heated furnace body (3) and an incineration assembly, the inside of the incineration hearth (1) is provided with two supports (4), the two supports (4) are connected with a support pipe (5), and the incineration assembly is fixedly connected with the support pipe (5); The outer side of the support pipe (5) is connected with at least four support rollers (6), the four support rollers (6) are oppositely arranged at the lower sides of the two ends of the length direction of the heated furnace body (3), the shaft center direction of the support rollers (6) is connected with a driving motor, the heated furnace body (3) is coaxially arranged outside the support pipe (5), the outer side surface of the heated furnace body (3) is in contact with the support rollers (6), one end of the support pipe (5) is connected with a liquid inlet pipe (7), and the concentrated solution obtained in step S3 enters into the support pipe (5) through the liquid inlet pipe (7); The middle part of the support pipe (5) is connected with a liquid spraying assembly, the incineration assembly comprises an external incineration assembly and an internal incineration assembly, the internal incineration assembly is located at the inner side of the heated furnace body (3), the external incineration assembly is located at the outer side of the heated furnace body (3), and the internal incineration assembly and the external incineration assembly are oppositely arranged.

7. The method for high efficiency treatment of terephthalic acid oxidation residue according to claim 6, characterized in that: The liquid spraying assembly comprises a first liquid spraying plate (8) and a second liquid spraying plate (9), both of which are circular arc plates, the first liquid spraying plate (8) and the second liquid spraying plate (9) are coaxially arranged with the heating furnace body (3) and the supporting pipe (5), and the first liquid spraying plate (8) and the second liquid spraying plate (9) are both provided with a plurality of liquid spraying holes (10) on the side opposite to the inner side of the heating furnace body (3).

8. The method for high efficiency treatment of terephthalic acid oxidation residue according to claim 7, characterized in that: The internal incineration assembly comprises two internal flame spraying arms (11), the length direction of the internal flame spraying arms (11) is parallel to the length direction of the supporting pipe (5), and the internal flame spraying arms (11) are uniformly provided with a plurality of first flame spraying nozzles on the side opposite to the inner side of the heating furnace body (3). The external incineration assembly comprises two external flame spraying arms (12), and the external flame spraying arms (12) are provided with a plurality of second flame spraying nozzles on the side opposite to the heating furnace body (3).

9. The method for high efficiency treatment of terephthalic acid oxidation residue according to claim 8, characterized in that: The upper portion of the heating furnace body (3) is provided with a circular arc-shaped material receiving plate (13), and a material receiving cavity is formed between the material receiving plate (13) and the heating furnace body (3), the material receiving cavity is provided with a material scraping device, the material scraping device is in contact with the inner wall of the heating furnace body (3), and the material receiving cavity is provided with a spiral conveying paddle (14), and the two ends of the material receiving plate (13) are in contact with the inner side of the heating furnace body (3). One end of the supporting pipe (5) is connected with a supporting frame, one end of the material receiving plate (13), the material scraping device and the spiral conveying paddle (14) are connected with the supporting frame, and the material receiving plate, the incineration assembly, the liquid spraying assembly and the material scraping device are supported by the supporting frame.

10. The method for high efficiency treatment of terephthalic acid oxidation residue according to claim 9, characterized in that: The material scraping device comprises a material scraping motor (15), a connecting shaft and a plurality of material scraping pieces (16), the plurality of material scraping pieces (16) are arranged along the length direction of the connecting shaft, the length of the material scraping piece (16) is equal to the length of the heating furnace body (3), one end of the material scraping piece (16) away from the connecting shaft is in contact with the inner side of the heating furnace body (3), the material scraping motor (15) is fixedly connected with the supporting frame, and the output shaft of the material scraping motor (15) is coaxially fixedly connected with the connecting shaft. The material receiving plate (13) is circular arc-shaped, the material receiving plate (13) is curved towards the inner side of the heating furnace body (3), the material receiving plate (13) comprises a material receiving section and an auxiliary plate (17), a spring rotating shaft is connected between the auxiliary plate (17) and the material receiving section, the outer end of the auxiliary plate (17) is in contact with the inner side of the heating furnace body (3), the auxiliary plate (17) rotates towards the side close to the material scraping device, and the rotating direction of the heating furnace body (3) is the same as the rotating direction of the auxiliary plate (17).

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