A device for producing electronic grade sulfuric acid based on organic amine absorption and desorption

Abstract

The utility model discloses a device based on organic amine absorption and desorption production electronic grade sulfuric acid, the device includes organic amine absorption and desorption device, SO2 gas enrichment device, circulating mixed gas device, drying device, quasi-isothermal multistage conversion device, fuming acid circulating absorption device, evaporation and impurity removal device, liquefied rectification device, gasification mixing device, electronic grade sulfuric acid circulating absorption device, and organic amine absorption and desorption device are connected circulating mixed gas device through SO2 gas enrichment device, and the circulating mixed gas device of supplement pure oxygen and inert gas can be connected with electronic grade sulfuric acid circulating absorption device in proper order through drying device, quasi-isothermal multistage conversion device, fuming acid circulating absorption device, evaporation and impurity removal device, liquefied rectification device, gasification mixing device.The device of the utility model can produce chemical reagent sulfuric acid simultaneously when producing electronic grade sulfuric acid, and the conversion absorption part tail gas "0" is discharged, and the comprehensive cost of investment operation is reduced by 10%-20%.

Description

Technical Field

[0001] This utility model relates to the fields of chemical engineering, metallurgy, and environmental protection, and in particular to the field of sulfuric acid production and desulfurization, energy saving, and ultra-low emission technology for various furnaces and reactors that generate SO2-containing flue gas. Specifically, it is a device for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines. Background Technology

[0002] Electronic-grade sulfuric acid, also known as high-purity sulfuric acid or ultra-pure sulfuric acid, is a crucial, ultra-clean basic chemical reagent widely used in the assembly and processing of semiconductors and very large-scale integrated circuits. It is primarily used for cleaning and etching silicon wafers, effectively removing impurities, inorganic residues, and carbon deposits. With the further miniaturization of chip manufacturing processes and the development of new energy technologies (such as lithium batteries and hydrogen energy), the purity and application scenarios of electronic-grade sulfuric acid will continue to upgrade. Electronic-grade sulfuric acid is a high-end product among sulfuric acid products developed and introduced in recent years, and its application in the electronics industry and other fields has developed rapidly. The electronics industry is developing rapidly globally, and Asia (especially China, South Korea, and Japan) is the global center of semiconductor and PCB manufacturing, leading to a surge in demand for electronic-grade sulfuric acid, with the demand volume continuing to grow.

[0003] Flue gas emitted from kilns or reactors in smelting and chemical industries contains SO2. Flue gas with a high concentration of SO2 is typically used to produce industrial-grade sulfuric acid; flue gas with a relatively low concentration of SO2 is usually concentrated and purified using organic amine absorption before being used to produce liquid SO2 or returned to the sulfuric acid system for sulfuric acid production. Organic amine desulfurization, due to the unique selectivity of organic amines in absorbing SO2, increases the SO2 concentration while effectively separating it from other substances. Its characteristics, such as sulfur resource recovery and reuse, and minimal secondary pollution, have led to its rapid adoption in the past decade. Currently, China has become the world's fastest-growing market for IT and LCD (Liquid Crystal Display) demand. The competitiveness of leading Chinese companies is continuously strengthening, with huge long-term growth potential, making it one of the fastest-growing and most dynamic sectors in the chemical industry. The demand for ultra-clean, high-purity reagents is also gradually increasing. Electronic-grade sulfuric acid accounts for approximately 30% of the total consumption of high-purity reagents, indicating a broad market prospect for electronic-grade sulfuric acid. Currently, the production process of electronic-grade sulfuric acid relies heavily on imported technology. Common methods for preparing electronic-grade sulfuric acid include distillation and gas absorption.

[0004] Distillation is a distillation method that uses reflux to separate liquid mixtures to achieve high purity. Atmospheric distillation typically involves temperatures as high as 330℃, requiring high-quality equipment. Vacuum distillation, on the other hand, operates at temperatures of 175–190℃ and pressures of 1.33 kPa–2.67 kPa. Distillation is energy-intensive and costly, and some impurities are difficult to remove. The resulting waste gases and acid mists are harmful to human health and environmental protection, making it suitable only for small-scale production.

[0005] The gas absorption method involves purifying the furnace gas to obtain ultrapure fuming sulfuric acid. The purified sulfur trioxide after the fuming sulfuric acid is evaporated and demisted is directly absorbed by ultrapure water. The purification of sulfur trioxide is the key to achieving product standards.

[0006] Multi-stage distillation is used to remove volatile impurities (such as HCl and NOx), but it is inefficient, difficult, lengthy, and results in inconsistent product quality and high investment and operating costs. Therefore, breakthroughs are urgently needed to address this issue. Utility Model Content

[0007] The purpose of this invention is to address the problems existing in the prior art by providing an apparatus for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines; the gas in the section after the organic amine absorption and desorption unit of this apparatus can be closed-looped to achieve zero emissions.

[0008] The objective of this utility model is achieved through the following technical solution:

[0009] An apparatus for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines, characterized in that: the apparatus comprises, in sequence, an organic amine absorption and desorption unit, an SO2 gas concentration unit, a circulating gas mixing unit, a drying unit, a quasi-isothermal multi-stage conversion unit, a fuming acid circulating absorption unit, an evaporation and impurity removal unit, a liquefaction distillation unit, a gasification mixing unit, and an electronic-grade sulfuric acid circulating absorption unit, wherein...

[0010] The organic amine absorption and desorption device is used to treat SO2 flue gas containing other components to obtain SO2 saturated gas containing pure SO2 and water, which is then transported to the SO2 gas enrichment device.

[0011] The SO2 gas enrichment device is used to condense and separate SO2 saturated gas into gas and liquid to obtain high-concentration SO2 gas with a volume concentration of 80% to 95%, which is then transported to the circulating gas mixing device.

[0012] The circulating gas mixing device is used to mix high-concentration SO2 gas with pure O2 and inert gas to obtain SO2 water-containing mixed gas with a volume concentration of 7% to 40%, and then transport it to the drying device. The source of inert gas is the inert gas that has not been absorbed by the subsequent device and the newly added inert gas. The inert gas is recycled to achieve zero emissions of tail gas.

[0013] The drying device uses concentrated sulfuric acid with a mass fraction of not less than 93% to dry the SO2-water mixture to obtain a dehydrated SO2 mixture, which is then transported to a quasi-isothermal multi-stage conversion unit.

[0014] The quasi-isothermal multi-stage conversion device is used to pressurize and heat the SO2 dehydrated gas mixture and then perform multi-stage conversion to obtain a SO3 mixture containing SO3, excess O2, inert gas and a small amount of impurities, which is then transported to the fuming acid recycling absorption device.

[0015] The fuming acid circulating absorption device uses fuming sulfuric acid to circulate and absorb SO3 in the SO3 mixture, and obtains fuming sulfuric acid with a free SO3 content of 26% to 32%, which is then transported to the evaporation and impurity removal device.

[0016] The evaporation and impurity removal device is used to evaporate and remove impurities from fuming sulfuric acid with a SO3 free content of 26% to 32% to obtain high-purity SO3 gas with a purity of over 99.99%, which is then transported to the liquefaction distillation unit.

[0017] The liquefaction distillation unit is used to liquefy and distill high-purity SO3 gas to obtain ultra-pure SO3 liquid with a purity of over 99.9999%, and then transport it to the gasification mixing unit.

[0018] The gasification mixing device is used to vaporize ultrapure SO3 liquid into ultrapure SO3 gas, which is then mixed with ultrapure inert gas to obtain electronic-grade sulfuric acid absorption gas, and then transported to the electronic-grade sulfuric acid recycling absorption device.

[0019] The electronic-grade sulfuric acid recycling absorption device uses electronic-grade sulfuric acid to circulate and absorb SO3 in the gas. The electronic-grade sulfuric acid obtained from the recycling absorption is filtered and then output as finished electronic-grade sulfuric acid.

[0020] The device also includes a chemical reagent sulfuric acid circulating absorption device, which is connected to the top of the fuming sulfuric acid absorption tower in the fuming acid circulating absorption device via a pipeline. The chemical reagent sulfuric acid circulating absorption device is equipped with a finished chemical reagent sulfuric acid output pipe and is connected to a circulating gas mixing device via an inert gas circulation pipe. After partial absorption of SO3 in the SO3 mixture supplied to the fuming acid circulating absorption device by the quasi-isothermal multi-stage conversion device, the SO3 mixture carrying the remaining SO3 enters the chemical reagent sulfuric acid absorption tower in the chemical reagent sulfuric acid circulating absorption device for absorption. The finished chemical reagent sulfuric acid obtained by the circulating absorption of SO3 is cooled and output through the finished chemical reagent sulfuric acid output pipe. The tail gas, composed of excess O2 and inert gas, returns to the circulating gas mixing device through the inert gas circulation pipe. The total SO3 absorption rate of the fuming acid circulating absorption device and the chemical reagent sulfuric acid circulating absorption device for SO3 in the SO3 mixture can reach 99.99%.

[0021] The aforementioned sulfuric acid circulating absorption device includes a sulfuric acid absorption tower, a sulfuric acid circulating tank equipped with a sulfuric acid circulating pump, and a sulfuric acid cooler. The lower part of the sulfuric acid absorption tower is connected to the top of a fuming sulfuric acid absorption tower via a pipeline to receive the SO3 mixture carrying residual SO3 output from the fuming sulfuric acid absorption tower. The bottom of the sulfuric acid absorption tower is connected to the sulfuric acid circulating tank via a pipeline. The sulfuric acid circulating pump in the sulfuric acid circulating tank is connected to the sulfuric acid cooler via a pipeline, and the sulfuric acid cooler is connected to a liquid distributor above the packing layer in the sulfuric acid absorption tower via a pipeline. A demister is also arranged above the liquid distributor in the sulfuric acid absorption tower, and the top of the sulfuric acid absorption tower is connected to a circulating gas mixing device via a pipeline. A finished sulfuric acid output pipe with a valve is arranged on the pipeline between the sulfuric acid cooler and the liquid distributor in the sulfuric acid absorption tower. An ultrapure water input pipe is arranged on the sulfuric acid circulating tank to replenish ultrapure water to balance the acid concentration.

[0022] The process of circulating absorption in the chemical reagent sulfuric acid absorption tower is as follows: A mixed gas of SO3 with a pressure of 9 kPa to 24 kPa and a temperature of 80°C to 130°C is introduced from the bottom of the chemical reagent sulfuric acid absorption tower and encounters the chemical reagent sulfuric acid with a pressure of 100 kPa to 150 kPa and a temperature of 60°C to 80°C, which is flowing downwards. The remaining SO3 is absorbed, generating atmospheric pressure chemical reagent sulfuric acid at a temperature of 70°C to 100°C. This sulfuric acid returns to the chemical reagent sulfuric acid circulation tank and is then pressurized by the chemical reagent sulfuric acid circulation pump and cooled by the chemical reagent sulfuric acid cooler to a pressure of 100 kPa to 150 kPa and a temperature of 60°C to 80°C, continuing to participate in the circulation absorption. The tail gas, consisting of excess O2 and inert gas, with a pressure of 6 kPa to 21 kPa and a temperature of 70°C to 90°C, is output from the top of the chemical reagent sulfuric acid absorption tower and returns to the circulating mixing device to continue participating in the circulation. The chemical reagent sulfuric acid circulation tank is replenished with ultrapure water through the ultrapure water input pipe to maintain acid concentration balance. The chemical reagent sulfuric acid in the chemical reagent sulfuric acid circulation tank, with a temperature of 70°C to 90°C, is pressurized by the chemical reagent sulfuric acid circulation pump and cooled by the chemical reagent sulfuric acid cooler to a pressure of 100 kPa to 150 kPa and a temperature of 60°C to 80°C. The finished chemical reagent sulfuric acid is then output through the finished chemical reagent sulfuric acid output pipe. The obtained finished chemical reagent sulfuric acid conforms to the national standard GB / T625.

[0023] The described organic amine absorption and desorption device includes an SO2 flue gas absorption tower, a lean-rich amine heat exchanger, and an SO2 desorption tower. The rich amine liquid outlet pipe at the bottom of the SO2 flue gas absorption tower (with a chimney at the top) is connected via the lean-rich amine heat exchanger to a liquid distributor above the packing layer in the middle of the SO2 desorption tower. The lean amine liquid outlet pipe at the bottom of the SO2 desorption tower is connected via the lean-rich amine heat exchanger to a liquid distributor above the upper packing layer in the middle of the SO2 flue gas absorption tower. The top of the SO2 desorption tower is connected to an SO2 gas enrichment device via a pipe, and the SO2 gas enrichment device is connected to the liquid distributor above the upper packing layer of the SO2 desorption tower via a return pipe. Flue gas containing impurities and volatile gases with a concentration of 0.1% to 7% and containing SO2 is purified and scrubbed through an adiabatic evaporation cooling and dust removal system before entering the SO2 flue gas absorption tower to undergo a gas-liquid absorption reaction with organic amine liquid. After SO2 removal, the flue gas meets the ultra-clean emission standard and is then discharged through a chimney. The rich amine liquid that has absorbed SO2 in the SO2 flue gas absorption tower is heated by a lean-rich amine heat exchanger and then enters the SO2 desorption tower. In the SO2 desorption tower, the rich amine liquid is desorbed by secondary steam generated by a reboiler, resulting in SO2 saturated gas at a temperature of 90℃ to 125℃.

[0024] The SO2 gas enrichment device includes an SO2 condenser and an SO2 vapor-liquid separator. The SO2 condenser is connected to the top of the SO2 desorption tower in the organic amine absorption and desorption device via a pipeline. The SO2 condenser can condense and cool the SO2 saturated gas, which is composed of pure SO2 and water, output from the SO2 desorption tower to 40℃~80℃ for dehydration. The SO2 condenser is connected to the cavity below the packing layer in the inner cavity of the SO2 vapor-liquid separator via a pipeline. The top of the SO2 vapor-liquid separator is connected to the circulating gas mixing device via a pipeline, and the bottom is connected to the liquid distributor above the packing layer of the SO2 desorption tower in the organic amine absorption and desorption device via a return liquid pipe. The SO2 condenser can perform gas-liquid separation on the dehydrated SO2 saturated gas to obtain a high-concentration SO2 gas with a volume concentration of 80%~95% SO2 and 20%~5% water, which is then transported to the circulating gas mixing device. The water obtained from the gas-liquid separation is returned to the organic amine absorption and desorption device via the return liquid pipe.

[0025] The circulating gas mixing device is equipped with a pure oxygen supply pipe, an inert gas supply pipe, an inert gas circulation pipe, and a high-concentration SO2 gas delivery pipe. The circulating gas mixing device is connected to the high-concentration SO2 gas outlet of the SO2 vapor-liquid separator in the SO2 gas enrichment device through the high-concentration SO2 gas delivery pipe. The circulating gas mixing device is connected to the drying device through a pipeline to deliver the SO2-water mixture to the drying device. The volume concentration of O2 in the SO2-water mixture reaches 7% to 40%. The circulating gas mixing device is connected to the electronic-grade sulfuric acid circulating absorption device through the inert gas circulation pipe.

[0026] The drying device includes a flue gas drying tower, a sulfuric acid circulating tank equipped with a sulfuric acid circulating pump, and a sulfuric acid cooler. The lower part of the inner cavity of the flue gas drying tower is connected to a circulating gas mixing device through a pipe to receive the SO2-water mixture output by the circulating gas mixing device. The bottom of the flue gas drying tower is connected to the sulfuric acid circulating tank through a pipe. The sulfuric acid circulating pump in the sulfuric acid circulating tank is connected to the sulfuric acid cooler through a pipe, and the sulfuric acid cooler is connected to a liquid distributor above the packing layer in the flue gas drying tower through a pipe. The top of the flue gas drying tower is connected to a quasi-isothermal multi-stage conversion device through a pipe to output SO2-water mixture with an SO2 volume concentration of 12% to 40% (preferably 20% to 40%) and a temperature of 50°C to 120°C. The sulfuric acid circulating tank is connected to a fuming sulfuric acid circulating tank and a chemical reagent sulfuric acid circulating tank through pipes to replenish the sulfuric acid.

[0027] The quasi-isothermal multi-stage conversion device includes an SO2 booster fan, a primary heat exchanger, a multi-stage converter, a quasi-isothermal pre-converter, a secondary heat exchanger, and a tertiary heat exchanger. The SO2 booster fan is connected to the top of the flue gas drying tower in the drying device via a pipeline to receive the SO2-water mixture. The SO2 booster fan is connected to the quasi-isothermal pre-converter equipped with a waste heat boiler via pipelines through the primary, secondary, and tertiary heat exchangers. The pipeline at the bottom of the quasi-isothermal pre-converter is connected to the second layer of the multi-stage converter via the tertiary heat exchanger. The pipeline at the bottom of the second layer of the multi-stage converter is connected to the first layer of the multi-stage converter via the secondary heat exchanger. The pipeline at the bottom of the first layer of the multi-stage converter is connected to the fuming acid circulation absorption device via the primary heat exchanger to output the SO3 mixture.

[0028] The SO2 dehydrated gas mixture, after passing through an SO2 booster fan, obtains a pressurized SO2 mixture with a pressure of 25 kPa to 40 kPa and a temperature of 70°C to 170°C. This pressurized mixture then undergoes a first-stage heat exchanger for a first-stage heating process, resulting in a SO2 first-stage heated mixture with a pressure of 24 kPa to 39 kPa and a temperature of 200°C to 300°C. This first-stage heated mixture then undergoes a second-stage heat exchanger for a second-stage heating process, resulting in a SO2 second-stage heated mixture with a pressure of 26 kPa to 38 kPa and a temperature of 250°C to 350°C. This second-stage heated mixture then undergoes a third-stage heat exchanger for a third-stage heating process, resulting in a SO2 conversion mixture with a pressure of 22 kPa to 37 kPa and a temperature of 380°C to 450°C. This SO2 conversion mixture then undergoes a first-stage conversion process in a quasi-isothermal pre-converter, outputting a first-stage conversion mixture with a pressure of 19 kPa to 34 kPa and a temperature of 500°C to 600°C. The gas mixture undergoes a primary conversion process, followed by a tertiary heat exchanger for primary cooling, resulting in a primary cooling gas with a pressure of 18 kPa to 33 kPa and a temperature of 410°C to 460°C. This primary cooling gas then undergoes a secondary conversion process in the second stage of a multi-stage converter, resulting in a secondary conversion gas with a pressure of 16 kPa to 31 kPa and a temperature of 450°C to 550°C. This secondary conversion gas then undergoes a secondary cooling process in the second stage of a heat exchanger, resulting in a secondary cooling gas with a pressure of 15 kPa to 30 kPa and a temperature of 410°C to 430°C. This secondary cooling gas then undergoes a tertiary conversion process in the first stage of a multi-stage converter, resulting in a tertiary conversion gas with a pressure of 13 kPa to 28 kPa and a temperature of 440°C to 460°C. Finally, this tertiary conversion gas undergoes a tertiary cooling process in the first stage of a heat exchanger, resulting in a SO3 mixture with a pressure of 12 kPa to 27 kPa and a temperature of 160°C to 220°C.

[0029] The first-stage conversion is completed in a quasi-isothermal converter, and the second-stage and third-stage conversions are carried out step by step in a multi-stage converter. The conversion rate of the first-stage conversion is 60% to 90%, and the sum of the conversion rates of the second-stage and third-stage conversions is 90% to 97%. The sum of the conversion rates of the first-stage, second-stage, and third-stage conversions can reach 99.5%.

[0030] The fuming sulfuric acid circulating absorption device includes a fuming sulfuric acid absorption tower, a fuming sulfuric acid circulating tank equipped with a fuming sulfuric acid circulating pump, and a fuming sulfuric acid cooler. The lower part of the fuming sulfuric acid absorption tower is connected to the first-stage heat exchanger in a quasi-isothermal multi-stage conversion device via a pipeline to receive the SO3 mixed gas output from the first-stage heat exchanger. The bottom of the fuming sulfuric acid absorption tower is connected to the fuming sulfuric acid circulating tank via a pipeline. The fuming sulfuric acid circulating pump in the fuming sulfuric acid circulating tank is connected to the fuming sulfuric acid cooler via a pipeline, and the fuming sulfuric acid cooler is connected to a liquid distributor above the packing layer in the fuming sulfuric acid absorption tower via a pipeline. A demister is also arranged above the liquid distributor in the fuming sulfuric acid absorption tower, and the top of the fuming sulfuric acid absorption tower is connected to a chemical reagent sulfuric acid circulating absorption device via a pipeline. The fuming sulfuric acid circulating tank is connected to the chemical reagent sulfuric acid circulating tank and an evaporation and impurity removal device via pipelines. The SO3 vaporizer is connected to replenish the circulating fuming sulfuric acid. A SO3 mixture with a pressure of 12 kPa to 27 kPa and a temperature of 160°C to 220°C is introduced from the bottom of the fuming sulfuric acid absorption tower and meets the fuming sulfuric acid with a pressure of 100 kPa to 150 kPa and a temperature of 50°C to 60°C flowing down from the top. The absorbed SO3 generates atmospheric fuming sulfuric acid with a temperature of 60°C to 80°C, which returns to the fuming sulfuric acid circulation tank. It is then pressurized by the fuming sulfuric acid circulation pump and cooled by the fuming sulfuric acid cooler to a pressure of 100 kPa to 150 kPa and a temperature of 50°C to 60°C to continue participating in the circulation absorption. The SO3 mixture with a pressure of 9 kPa to 24 kPa and a temperature of 80°C to 130°C containing the remaining SO3 is transported to the chemical reagent sulfuric acid absorption tower for circulation absorption.

[0031] The evaporation and impurity removal device includes an evaporator nicotinic acid inlet pipe and an SO3 evaporator. The inlet end of the evaporator nicotinic acid inlet pipe, equipped with an evaporation valve, is located on the pipeline between the fuming sulfuric acid circulating pump and the fuming sulfuric acid cooler. The outlet end of the evaporator nicotinic acid inlet pipe is connected to the SO3 evaporator, which is connected to the fuming sulfuric acid circulating tank via a reflux pipe. The SO3 evaporator, equipped with low-pressure steam, is connected to a liquefaction distillation unit via a pipeline to output high-purity SO3 gas. The free SO3 content from the fuming sulfuric acid circulating tank reaches 2%. Fuming sulfuric acid of 6% to 32% is pressurized to 100 kPa to 150 kPa by a fuming sulfuric acid circulation pump and then fed into an SO3 evaporator with an evaporation temperature of 90℃ to 130℃. After evaporation and impurity removal, high-purity SO3 gas with a pressure of 20 kPa to 50 kPa and a temperature of 90℃ to 140℃ is output to a liquefied distillation unit. Fuming sulfuric acid from the fuming sulfuric acid circulation tank is evaporated to obtain atmospheric pressure fuming sulfuric acid with a temperature of 90℃ to 110℃ and a free SO3 content of 20% to 23%, which is returned to the fuming sulfuric acid circulation tank.

[0032] The liquefaction distillation apparatus includes an SO3 condenser and a liquid SO3 storage tank. The SO3 condenser, with a condensation temperature of 30℃ to 50℃, is connected via a pipeline to the output end of an SO3 evaporator to receive high-purity SO3 gas at a pressure of 20kPa to 50kPa and a temperature of 90℃ to 140℃. The SO3 condenser is connected via a pipeline to the liquid SO3 storage tank to output ultra-pure SO3 liquid with a purity of 99.9999% or higher. The liquid SO3 storage tank is connected via a pipeline to the vaporization... The mixing device is connected; the SO3 condenser and / or liquid SO3 storage tank are connected to the circulating gas mixing device through pipelines; high-purity SO3 gas with a pressure of 20kPa to 50kPa and a temperature of 90℃ to 140℃ enters the SO3 condenser with a temperature of 30℃ to 50℃ for liquefaction and distillation to obtain ultra-pure SO3 liquid with a pressure of 0kPa to 1kPa, a temperature of 20℃ to 35℃ and a purity of 99.9999% or higher, which is then sent to the liquid SO3 storage tank for storage.

[0033] The vaporization mixing device includes an SO3 vaporizer and an ultrapure SO3 gas output pipe. The upper or lower part of the SO3 vaporizer, with a vaporization temperature of 50℃~80℃, is connected to the bottom of a liquid SO3 storage tank via a pipe. The SO3 vaporizer can receive ultrapure SO3 liquid with a pressure of 0kPa~1kPa and a temperature of 20℃~35℃ from the liquid SO3 storage tank and vaporize it to output ultrapure SO3 gas with a pressure of 10kPa~15kPa and a temperature of 60℃~80℃. The top of the SO3 vaporizer is connected to the electronic-grade sulfuric acid absorption device via the ultrapure SO3 gas output pipe. The lower part of the tower is connected to an ultrapure SO3 gas output pipe, on which an ultrapure inert gas input pipe is arranged. The ultrapure inert gas input pipe is mixed with the ultrapure SO3 gas in the ultrapure SO3 gas output pipe at a pressure of 10 kPa to 15 kPa and a temperature of 60°C to 80°C to obtain electronic-grade sulfuric acid absorbing gas. The pressure of the electronic-grade sulfuric acid absorbing gas is 10 kPa to 15 kPa and the temperature is 60°C to 80°C. The volume ratio of the ultrapure SO3 gas to the ultrapure inert gas is 70% to 40%: 30% to 60%, and the purity of the ultrapure inert gas is above 99.999%.

[0034] The electronic-grade sulfuric acid circulating absorption device includes an electronic-grade sulfuric acid absorption tower, an electronic-grade ultrapure water inlet pipe, an electronic-grade sulfuric acid circulating pump, a cluster heat exchanger, a filter, and an electronic-grade sulfuric acid outlet pipe. The lower part of the electronic-grade sulfuric acid absorption tower is connected to the ultrapure SO3 gas outlet pipe to obtain electronic-grade sulfuric acid absorption gas. The top of the electronic-grade sulfuric acid absorption tower is connected to a circulating gas mixing device via a pipe, and the bottom of the electronic-grade sulfuric acid absorption tower is connected to an electronic-grade sulfuric acid circulating tank via a pipe. The electronic-grade sulfuric acid circulating pump in the electronic-grade sulfuric acid circulating tank is connected to the cluster heat exchanger via a pipe, and the cluster heat exchanger is connected to a liquid distributor above the packing layer in the electronic-grade sulfuric acid absorption tower via a pipe. A demister is also arranged above the liquid distributor in the electronic-grade sulfuric acid absorption tower. A pipe with a valve is arranged on the pipe between the cluster heat exchanger and the liquid distributor in the electronic-grade sulfuric acid absorption tower, leading to the filter. The outlet is connected to the electronic-grade sulfuric acid storage tank via an electronic-grade sulfuric acid output pipe. An electronic-grade ultrapure water input pipe is installed on the electronic-grade sulfuric acid circulation tank to replenish the ultrapure water and balance the acid concentration. The electronic-grade sulfuric acid absorption gas is introduced from the bottom of the electronic-grade sulfuric acid absorption tower and encounters the electronic-grade sulfuric acid, which has a pressure of 10kPa–15kPa and a temperature of 60°C–80°C, flowing downwards. The gas is absorbed, generating atmospheric pressure electronic-grade sulfuric acid at a temperature of 70°C–100°C. This gas returns to the electronic-grade sulfuric acid circulation tank and is pressurized by the electronic-grade sulfuric acid circulation pump and cooled by a cluster heat exchanger to a pressure of 10kPa–15kPa and a temperature of 60°C–80°C, continuing to participate in the circulation absorption. Meanwhile, inert gas with a pressure of 6kPa–11kPa and a temperature of 70°C–90°C is output from the top of the electronic-grade sulfuric acid absorption tower and returns to the circulating mixing device to continue the circulation, resulting in zero tail gas emissions.

[0035] The absorption rate of ultrapure SO3 gas in the electronic-grade sulfuric acid absorption gas can reach 99.99%.

[0036] The electronic-grade sulfuric acid in the circulating tank has a mass concentration of 95% to 98.6%, and the electronic-grade ultrapure water used has a purity of 99.9999 wt%.

[0037] The electronic-grade sulfuric acid in the circulating tank is pressurized by the circulating pump to a pressure not exceeding 100 kPa and cooled by the bundled heat exchanger to a temperature not exceeding 40°C. It is then sent to a filter with a pore size of 0.1 μm to 1 μm for 1 to 3 stages of filtration to obtain the finished electronic-grade sulfuric acid. The finished electronic-grade sulfuric acid is output to the electronic-grade sulfuric acid storage tank for nitrogen sealing through the electronic-grade sulfuric acid output pipe.

[0038] The electronic-grade sulfuric acid obtained by the device provided by this utility model conforms to the national standard GB / T41881-2022.

[0039] It should be noted that the national standard GB / T41881-2022 specifies the quality of electronic-grade sulfuric acid from high to low as follows: E1, E2, E3, E4, and E5 (corresponding to G5, G4, G3, G2, and G1 levels in the Semiconductor Equipment and Materials International (SEMI) standards, respectively. The indicators of E5 level are basically the same as those of G1 level, and the indicators of E1 level are basically the same as those of G5 level). The finished electronic-grade sulfuric acid obtained by the device provided by this utility model can reach a maximum of E1 level and will not be lower than E5 level.

[0040] All pressures mentioned in the device provided by this utility model are gauge pressures.

[0041] Compared with the prior art, the present invention has the following advantages:

[0042] The device provided by this invention uses organic amine absorption and desorption technology to purify SO2 and remove volatile impurities; then, pure oxygen is reacted with high-concentration SO2 to produce fuming sulfuric acid and chemical reagent sulfuric acid; next, the fuming sulfuric acid is evaporated to produce SO3, and the SO3 is condensed and distilled to remove reducing substances; finally, in a clean environment, electronic-grade sulfuric acid with an electronic-grade ultrapure water balance acid concentration is used to absorb ultrapure SO3 to produce ultrapure sulfuric acid products that meet the GB / T41881-2022 standard; this process can simultaneously produce ultrapure sulfuric acid and chemical reagent sulfuric acid, with stable and reliable product quality, and a 10%-20% reduction in overall investment and operating costs; it can also achieve zero emissions of flue gas.

[0043] The device provided by this invention utilizes the characteristic of organic amine absorbents to selectively adsorb SO2. Its key feature is the selective adsorption of SO2 gas from flue gas, while other media (NO...) are absorbed. x (e.g., HF, HCl) are retained in the flue gas and treated together with it before being discharged; this process achieves the purification and concentration of SO2 gas, solving the problem of removing volatile gases by distillation.

[0044] The device provided by this utility model utilizes purified, high-concentration SO2 gas, which is mixed with pure oxygen and inert gas to produce a pure SO3 mixture. The SO3 mixture enters an ultrapure fuming sulfuric acid absorption tower to obtain fuming sulfuric acid (preventing other substances from entering the system). The SO3 mixture after absorption by the fuming sulfuric acid absorption tower enters a chemical reagent sulfuric acid absorption tower to absorb the remaining SO3 gas. The chemical reagent sulfuric acid circulation tank is replenished with ultrapure water to maintain acid concentration balance while producing chemical reagent sulfuric acid that meets the GB / T625 national standard.

[0045] The device provided by this invention utilizes fuming sulfuric acid to obtain high-purity SO3 gas through evaporation. The high-purity SO3 gas is then liquefied and distilled in an SO3 condenser to obtain ultra-pure SO3 liquid. The liquefaction and distillation process removes reducing gases based on the difference in boiling points, thus completing the liquefaction and distillation process.

[0046] The device provided by this utility model heats and vaporizes ultrapure SO3 liquid. The ultrapure SO3 gas generated after heating and vaporization is mixed with an introduced ultrapure inert gas and then enters an electronic-grade sulfuric acid absorption tower. The electronic-grade sulfuric acid absorption tower directly absorbs the ultrapure sulfuric acid, which can be replenished with electronic-grade ultrapure water. The absorbed electronic-grade sulfuric acid is filtered in 1 to 3 stages (the filter membrane pore size is 0.1 to 1 μm) to obtain the finished electronic-grade sulfuric acid. The finished electronic-grade sulfuric acid is sent from the electronic-grade sulfuric acid output pipe into a fluoropolymer-lined electronic-grade sulfuric acid storage tank to obtain ultrapure sulfuric acid (meeting the GB / T41881-2022 standard) product.

[0047] The device provided by this utility model purifies SO2 from raw material gas using organic amines, and then absorbs electronic-grade sulfuric acid through a process of fuming sulfuric acid distillation, SO3 liquefaction distillation, and preparation of electronic-grade ultrapure water. This process enables large-scale production of electronic-grade sulfuric acid, while simultaneously producing chemical reagent sulfuric acid. It has the advantages of a short process flow, no secondary pollution, ultra-clean emissions, and the ability to scale up and automate the equipment. The overall investment and operating costs are reduced by 20%-40%, making it suitable for widespread use. Attached Figure Description

[0048] Appendix Figure 1 A schematic diagram of an apparatus for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines, provided for this utility model.

[0049] Wherein: 1—SO2 flue gas absorption tower; 2—Amine-rich heat exchanger; 3—SO2 desorption tower; 4—Pure oxygen replenishment pipe; 5—Circulating gas mixing device; 6—Flue gas drying tower; 7—SO2 booster fan; 8—First-stage heat exchanger; 9—Multi-stage converter; 10—Fogging sulfuric acid absorption tower; 11—Fogging sulfuric acid cooler; 12—Fogging sulfuric acid circulation pump; 13—Evaporator nicotinic acid inlet pipe; 14—Chemical reagent sulfuric acid absorption tower; 15—Ultrapure water inlet pipe; 16—Chemical reagent sulfuric acid circulation pump; 17—Chemical reagent sulfuric acid cooler; 18—Finished chemical reagent sulfuric acid 19—Ultra-pure SO3 gas output pipe; 20—Electronic-grade sulfuric acid absorption tower; 21—Electronic-grade ultrapure water input pipe; 22—Electronic-grade sulfuric acid circulating pump; 23—Cluster heat exchanger; 24—Filter; 25—Electronic-grade sulfuric acid output pipe; 26—SO3 vaporizer; 27—Liquid SO3 storage tank; 28—SO3 condenser; 29—SO3 evaporator; 30—Waste heat boiler; 31—Quasi-isothermal pre-converter; 32—Third-stage heat exchanger; 33—Second-stage heat exchanger; 34—SO2 vapor-liquid separator; 35—SO2 condenser; 36—Chimney. Detailed Implementation

[0050] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present invention will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed description will be omitted.

[0051] The terms “a,” “one,” “the,” and “the” are used to indicate the existence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended meaning of inclusion and that other elements / components / etc. may exist in addition to the listed elements / components / etc.

[0052] like Figure 1The apparatus shown is for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines. The apparatus includes an SO2 flue gas absorption tower 1, a lean-rich amine heat exchanger 2, an SO2 desorption tower 3, a pure O2 replenishment pipe 4, a circulating gas mixing device 5, a flue gas drying tower 6, an SO2 booster fan 7, a primary heat exchanger 8, a multi-stage converter 9, a fuming sulfuric acid absorption tower 10, a fuming sulfuric acid cooler 11, a fuming sulfuric acid circulation pump 12, an evaporator nicotinic acid inlet pipe 13, a chemical reagent sulfuric acid absorption tower 14, an ultrapure water inlet pipe 15, a chemical reagent sulfuric acid circulation pump 16, and a chemical reagent sulfuric acid cooler. 17. Finished chemical reagent sulfuric acid output pipe; 18. Ultrapure SO3 gas output pipe; 19. Electronic grade sulfuric acid absorption tower; 20. Electronic grade ultrapure water input pipe; 21. Electronic grade sulfuric acid circulating pump; 22. Cluster heat exchanger; 23. Filter; 24. Electronic grade sulfuric acid output pipe; 25. SO3 vaporizer; 26. Liquid SO3 storage tank; 27. SO3 condenser; 28. SO3 evaporator; 29. ​​Waste heat boiler; 30. Quasi-isothermal pre-converter; 31. Three-stage heat exchanger; 32. Two-stage heat exchanger; 33. SO2 vapor-liquid separator; 34. SO2 condenser; 35. Chimney; 36. The SO2 desorption tower 3 is made of 316L stainless steel; the circulating gas mixing device 5, the primary heat exchanger 8, the multi-stage converter 9, the quasi-isothermal pre-converter 31, the tertiary heat exchanger 32, and the secondary heat exchanger 33 are all made of S30408 ​​stainless steel; the fuming sulfuric acid absorption tower 10 and the chemical reagent sulfuric acid absorption tower 14 are made of F4 steel-lined steel; the fuming sulfuric acid cooler 11 and the chemical reagent sulfuric acid cooler 17 are made of Hastelloy alloy; the fuming sulfuric acid circulation pump 12 and the chemical reagent sulfuric acid circulation pump 16 are fluoroplastic-lined magnetic pumps; SO3 vaporization... The equipment 26, liquid SO3 storage tank 27, and SO3 condenser 28 are made of 304L or 316L material; the electronic-grade sulfuric acid absorption tower 20 is lined with S30408 ​​ultrapure PTFE and the packing is made of ultrapure PFA Pall rings; the cluster heat exchanger 23 is made of ultrapure PFA material; the electronic-grade sulfuric acid circulation pump 22 is an ultrapure PFA magnetic pump; the filter 24 is lined with S30408 ​​ultrapure PTFE and filled with ultrapure PFA / PTFE membrane filter element; the pipelines and valves required for the process are made of S30408 ​​stainless steel lined with ultrapure PTFE.

[0053] The connection of the device is as follows: SO2-containing flue gas emitted from various kilns or reactors in smelting, chemical, and other industries is purified and scrubbed through an adiabatic evaporation cooling and dust removal system before being input from the bottom of SO2 flue gas absorption tower 1. The rich amine liquid output pipe at the bottom of SO2 flue gas absorption tower 1 is connected to the liquid distributor above the packing layer in the middle of SO2 desorption tower 3 via a lean-rich amine heat exchanger 2. The lean amine liquid output pipe at the bottom of SO2 desorption tower 3 is connected to the liquid distributor above the packing layer in the upper middle of SO2 flue gas absorption tower 1 via a lean-rich amine heat exchanger 2. The top of SO2 flue gas absorption tower 1 is equipped with a chimney 36 (which is also the only device in this utility model that has an external chimney). (The exhaust gas is recycled from the gas generated during the process in the downstream unit). The top of the SO2 desorption tower 3 is connected to the SO2 condenser 35 via a pipeline, and the SO2 condenser 35 is connected to the SO2 vapor-liquid separator 34 via a pipeline. The top of the SO2 vapor-liquid separator 34 is connected to the circulating gas mixing device 5 via a pipeline, and the bottom of the SO2 vapor-liquid separator 34 is connected to the liquid distributor above the packing layer of the SO2 desorption tower 3 via a pipeline. The circulating gas mixing device 5 is connected to the pure O2 replenishment pipe 4, and the circulating gas mixing device 5 is also connected to the top of the chemical reagent sulfuric acid absorption tower 14 and the electronic grade sulfuric acid absorption tower 20 via pipelines respectively. Inert gas is added and recycled to achieve zero emissions of exhaust gas. If needed, the circulating gas mixing device 5 can also be connected to an inert gas supply device. The circulating gas mixing device 5 is connected to the lower part of the flue gas drying tower 6 via a pipeline. The top of the flue gas drying tower 6 is connected to the SO2 booster fan 7 via a pipeline, and the bottom of the flue gas drying tower 6 is connected to a drying sulfuric acid circulation tank equipped with a drying sulfuric acid circulation pump via a pipeline. The drying sulfuric acid circulation pump is connected to a drying sulfuric acid cooler via a pipeline, and the drying sulfuric acid cooler is connected to a liquid distributor above the packing layer inside the flue gas drying tower 6 via a pipeline. This drying sulfuric acid circulation tank can also be connected to a fuming sulfuric acid circulation tank. A chemical reagent sulfuric acid circulation tank is connected to replenish the dried sulfuric acid; an SO2 booster fan 7 is connected to a quasi-isothermal pre-converter 31 via a pipeline through a primary heat exchanger 8, a secondary heat exchanger 33, and a tertiary heat exchanger 32. A waste heat boiler 30 is installed on the quasi-isothermal pre-converter 31. The pipeline at the bottom of the quasi-isothermal pre-converter 31 is connected to the second layer of the multi-stage converter 9 via the tertiary heat exchanger 32. The pipeline at the bottom of the second layer of the multi-stage converter 9 is connected to the first layer of the multi-stage converter 9 via the secondary heat exchanger 33. The pipeline at the bottom of the first layer of the multi-stage converter 9 is connected to the lower part of the fuming sulfuric acid absorption tower 10 via the primary heat exchanger 8.The top of the fuming sulfuric acid absorption tower 10 is connected to the chemical reagent sulfuric acid absorption tower 14 via a pipeline, and the bottom of the fuming sulfuric acid absorption tower 10 is connected to a fuming sulfuric acid circulation tank equipped with a fuming sulfuric acid circulation pump 12 via a pipeline. The fuming sulfuric acid circulation pump 12 is connected to the fuming sulfuric acid cooler 11 via a pipeline, and the fuming sulfuric acid cooler 11 is connected to the liquid distributor above the packing layer inside the fuming sulfuric acid absorption tower 10 via a pipeline. A demister is also arranged above the liquid distributor inside the fuming sulfuric acid absorption tower 10. The fuming sulfuric acid circulation tank can also be connected to the chemical reagent sulfuric acid circulation tank and the SO3 vaporizer 26 to supplement the circulation. Fuming sulfuric acid is used; the top of the chemical reagent sulfuric acid absorption tower 14 is connected to the circulating gas mixing device 5 via a pipeline, and the bottom of the chemical reagent sulfuric acid absorption tower 14 is connected to the chemical reagent sulfuric acid circulation tank equipped with a chemical reagent sulfuric acid circulation pump 16 via a pipeline. The chemical reagent sulfuric acid circulation pump 16 is connected to the chemical reagent sulfuric acid cooler 17 via a pipeline, and the chemical reagent sulfuric acid cooler 17 is connected to the liquid distributor above the packing layer inside the chemical reagent sulfuric acid absorption tower 14 via a pipeline. A demister is also arranged above the liquid distributor inside the chemical reagent sulfuric acid absorption tower 14. Ultrapure sulfuric acid is arranged on the chemical reagent sulfuric acid circulation tank. A water inlet pipe 15 is used to replenish ultrapure water to balance the acid concentration. A finished chemical reagent sulfuric acid outlet pipe 18 with a valve is arranged on the pipeline between the chemical reagent sulfuric acid cooler 17 and the liquid distributor in the chemical reagent sulfuric acid absorption tower 14. An evaporator nicotinic acid inlet pipe 13 with a valve is arranged on the pipeline between the fuming sulfuric acid circulation pump 12 and the fuming sulfuric acid cooler 11. The evaporator nicotinic acid inlet pipe 13 is connected to the SO3 evaporator 29, and the SO3 evaporator 29 is connected to the fuming sulfuric acid circulation tank through a return pipe. The SO3 evaporator 29, equipped with low-pressure steam, is connected to the SO3 condenser 28 through a pipeline. The two are connected (a demister can be installed on the pipeline between them, and the trace sulfuric acid collected by the demister is returned to the drying sulfuric acid absorption tower 6 to participate in the drying process); the SO3 condenser 28 is connected to the liquid SO3 storage tank 27 through a pipeline; the liquid SO3 storage tank 27 is connected to the upper part (the SO3 vaporizer 26 has a built-in sink pipe) or the lower part of the SO3 vaporizer 26 through a pipeline, and the top of the SO3 vaporizer 26, which is equipped with low-pressure steam, is connected to the lower part of the electronic grade sulfuric acid absorption tower 20 through the ultra-pure SO3 gas output pipe 19, and the ultra-pure SO3 gas output pipe 19 is matched with an ultra-pure inert gas input pipe;The top of the electronic-grade sulfuric acid absorption tower 20 is connected to the circulating gas mixing device 5 via a pipeline, and the bottom of the electronic-grade sulfuric acid absorption tower 20 is connected to the electronic-grade sulfuric acid circulation tank equipped with an electronic-grade sulfuric acid circulation pump 22 via a pipeline. The electronic-grade sulfuric acid circulation pump 22 is connected to the cluster heat exchanger 23 via a pipeline, and the cluster heat exchanger 23 is connected to the liquid distributor above the packing layer inside the electronic-grade sulfuric acid absorption tower 20 via a pipeline. A demister is also arranged above the liquid distributor inside the electronic-grade sulfuric acid absorption tower 20. An electronic-grade ultrapure water inlet pipe 21 is arranged on the electronic-grade sulfuric acid circulation tank to replenish the electronic-grade ultrapure water to balance the acid concentration. A pipe with a valve is arranged on the pipeline between the cluster heat exchanger 23 and the liquid distributor inside the electronic-grade sulfuric acid absorption tower 20, leading to a filter 24. The outlet of the filter 24 is connected to the electronic-grade sulfuric acid storage tank via an electronic-grade sulfuric acid outlet pipe 25. Valves are configured on the above-mentioned pipelines as needed.

[0054] The key technologies for high-grade E1 and E2 electronic-grade sulfuric acid products are ultra-pure production equipment and a clean control environment. This set of equipment can produce chemical reagent sulfuric acid and electronic-grade sulfuric acid while meeting ultra-clean emission standards, regardless of the concentration of SO2-containing flue gas.

[0055] The process flow steps for using the apparatus for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines provided by this utility model are as follows:

[0056] A. Flue gas containing SO2 (0.1%–7% SO2 volume concentration) and impurities, along with volatile gases, undergoes adiabatic evaporation cooling and dust removal through a purification and scrubbing system before entering SO2 flue gas absorption tower 1 for gas-liquid absorption reaction. After SO2 removal, the flue gas meets ultra-clean emission standards and is then discharged through chimney 36. The amine-rich liquid, having absorbed SO2 in SO2 flue gas absorption tower 1, is then heated by a lean-amine heat exchanger 2 before entering SO2 desorption tower 3. In SO2 desorption tower 3, the amine-rich liquid undergoes desorption by secondary steam generated by a reboiler, yielding pure SO2 and water at a temperature of 90℃–125℃, resulting in SO2-saturated gas.

[0057] B. Saturated SO2 gas is first cooled to 40℃~80℃ to remove water, and then dehydrated by gas-liquid separation to obtain high-concentration SO2 gas with a volume concentration of 80%~95% SO2 and 20%~5% water.

[0058] C. A mixture of high-concentration SO2 gas, pure O2, and inert gas is used to obtain a water-containing SO2 mixture at a temperature of 50℃~90℃. The volume concentration of SO2 in the water-containing SO2 mixture is 7%~40%, and the volume concentration of O2 is 7%~40%.

[0059] D. A mixture of SO2 and water is dried with concentrated sulfuric acid of not less than 93% by mass to obtain a dehydrated SO2 mixture at a temperature of 50℃~120℃. The volume concentration of SO2 in the dehydrated SO2 mixture is 12%~40%, preferably 20%~40%.

[0060] E. Pressurizing the SO2 dehydration mixture yields a pressurized SO2 mixture with a pressure of 25 kPa to 40 kPa and a temperature of 70°C to 170°C. After multi-stage heating, this pressurized SO2 mixture yields a converted SO2 mixture with a pressure of 22 kPa to 37 kPa and a temperature of 380°C to 450°C. This converted SO2 mixture undergoes further multi-stage conversion to yield an SO3 mixture with a pressure of 12 kPa to 27 kPa and a temperature of 160°C to 220°C. The SO3 mixture consists of SO3, excess O2, inert gases, and trace impurities. The overall SO2 conversion rate after multi-stage conversion reaches 99.5%.

[0061] F. A mixture of SO3 gas with a pressure of 12kPa to 27kPa and a temperature of 160℃ to 220℃ is introduced from the bottom of the fuming sulfuric acid absorption tower 10 and encounters fuming sulfuric acid with a pressure of 100kPa to 150kPa and a temperature of 50℃ to 60℃ flowing downwards. Some of the absorbed SO3 is converted into atmospheric pressure fuming sulfuric acid at a temperature of 60℃ to 80℃. This gas returns to the fuming sulfuric acid circulation tank and is pressurized by the fuming sulfuric acid circulation pump 12 and cooled by the fuming sulfuric acid cooler 11 to a pressure of 100kPa to 150kPa and a temperature of 50℃ to 60℃. The SO3 mixture, containing 35%–50% of the SO3 in the SO3 mixture after being absorbed by fuming sulfuric acid, and with a pressure of 9 kPa–24 kPa and a temperature of 80°C–130°C, is then transported to the chemical reagent sulfuric acid absorption tower 14 for further absorption. This SO3 mixture, with a pressure of 9 kPa–24 kPa and a temperature of 80°C–130°C, is introduced from the bottom of the chemical reagent sulfuric acid absorption tower 14 and encounters the chemical reagent sulfuric acid, with a pressure of 100 kPa–150 kPa and a temperature of 60°C–80°C, flowing downwards. The remaining SO3 is absorbed, generating atmospheric sulfuric acid at a temperature of 70℃~100℃. This sulfuric acid is returned to the sulfuric acid circulation tank and pressurized by the sulfuric acid circulation pump 16 and cooled by the sulfuric acid cooler 17 to a pressure of 100kPa~150kPa and a temperature of 60℃~80℃. It then continues to participate in the circulation absorption. Meanwhile, the tail gas from the top of the sulfuric acid absorption tower 14, composed of excess O2 and inert gases, with a pressure of 6kPa~21kPa and a temperature of 70℃~90℃, returns to step C to continue the circulation. The reagent sulfuric acid circulation tank is replenished with ultrapure water through the ultrapure water inlet pipe 15 to maintain acid concentration balance. The reagent sulfuric acid in the chemical reagent sulfuric acid circulation tank, with a temperature of 70℃~90℃, is pressurized by the chemical reagent sulfuric acid circulation pump 16 and cooled by the chemical reagent sulfuric acid cooler 17 to a pressure of 100kPa~150kPa and a temperature of 60℃~80℃, and then output through the finished chemical reagent sulfuric acid outlet pipe 18. The total SO3 absorption rate in the SO3 mixture can reach 99.99% after absorption by the fuming sulfuric acid circulation and the chemical reagent sulfuric acid circulation.

[0062] G. Fuming sulfuric acid with a SO3 free concentration of 26%–32% in the fuming sulfuric acid circulation tank is pressurized to 100 kPa–150 kPa by the fuming sulfuric acid circulation pump 12, and then sent to the SO3 evaporator 29 by the fuming sulfuric acid inlet pipe 13. The SO3 evaporator 29, heated by low-pressure steam, evaporates and removes impurities from the fuming sulfuric acid with a SO3 free concentration of 26%–32%, obtaining SO3 gas with a pressure of 20 kPa–50 kPa and a temperature of 90°C–140°C. Fuming sulfuric acid with a SO3 free content of 26% to 32% is reduced to atmospheric pressure fuming sulfuric acid with a SO3 free content of 20% to 23% and a temperature of 90℃ to 110℃ after SO3 evaporation and returned to the fuming sulfuric acid circulation tank; the evaporation process of SO3 evaporator 29 can remove trace heavy metals and dust entrained in it. The SO3 gas evaporated by SO3 evaporator 29 is then removed by demister to remove trace sulfuric acid entrained in it, resulting in high-purity SO3 gas with a purity of over 99.99%.

[0063] H. High-purity SO3 gas enters SO3 condenser 28 at a temperature of 30℃~50℃ for liquefaction distillation (distillation removes other non-condensable gases based on its different properties from other non-condensable gases), obtaining ultra-pure SO3 liquid with a pressure of 0kPa~1kPa, a temperature of 20℃~35℃ and a purity of 99.9999% or higher, which is then sent to liquid SO3 storage tank 27 for storage; the gaseous reducing gas (such as SO2 gas) produced by liquefaction distillation returns to the circulating gas mixing device 5 in step C through a valved pipeline installed on SO3 condenser 28 or liquid SO3 storage tank 27.

[0064] 1. Ultrapure SO3 liquid is fed into SO3 vaporizer 26, which has a vaporization temperature of 50℃~80℃. SO3 vaporizer 26, which is heated by low-pressure steam, outputs ultrapure SO3 gas with a pressure of 10kPa~15kPa and a temperature of 60℃~80℃. The electronic-grade sulfuric acid absorption gas obtained by mixing ultrapure SO3 gas with ultrapure inert gas is input into electronic-grade sulfuric acid absorption tower 20. The residual liquid produced by SO3 vaporizer 26 is transported to fuming sulfuric acid circulation tank to participate in SO3 absorption.

[0065] J. Electronic-grade sulfuric acid absorption gas with a pressure of 10kPa~15kPa and a temperature of 60℃~80℃ is introduced from the bottom of the electronic-grade sulfuric acid absorption tower 20 and encounters electronic-grade sulfuric acid with a pressure of 10kPa~15kPa and a temperature of 60℃~80℃ flowing down from above. The gas is absorbed, generating atmospheric pressure electronic-grade sulfuric acid with a temperature of 70℃~100℃. This gas returns to the electronic-grade sulfuric acid circulation tank and is then pressurized by the electronic-grade sulfuric acid circulation pump 22 and cooled by the cluster heat exchanger 23 to a pressure of 10kPa~15kPa and a temperature of 60℃. Electronic-grade sulfuric acid at ~80℃ continues to participate in the circulation absorption, and the inert gas output from the top of the electronic-grade sulfuric acid absorption tower 20, with a pressure of 6kPa~11kPa and a temperature of 70℃~90℃, returns to step C to continue the circulation, resulting in zero tail gas emissions. The electronic-grade sulfuric acid circulation tank is replenished with electronic-grade ultrapure water through the electronic-grade ultrapure water input pipe 21 to maintain acid concentration balance. The purity of the electronic-grade ultrapure water is 99.9999wt%, and the absorption rate of ultrapure SO3 gas in the electronic-grade sulfuric acid absorption gas can reach 99.99%.

[0066] K. Electronic-grade sulfuric acid is pressurized by electronic-grade sulfuric acid circulation pump 22 and cooled by cluster heat exchanger 23 to a pressure not exceeding 100 kPa and a temperature not exceeding 40°C. It is then sent to filter 24 with a filter membrane pore size of 0.1 μm to 1 μm for 1 to 3 stages of filtration to obtain finished electronic-grade sulfuric acid. The finished electronic-grade sulfuric acid is output to electronic-grade sulfuric acid storage tank for nitrogen sealing through electronic-grade sulfuric acid output pipe 25. The finished electronic-grade sulfuric acid conforms to the national standard GB / T41881-2022.

[0067] The apparatus for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines provided by this utility model will be further illustrated below in conjunction with the apparatus and process flow for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines.

[0068] SO2-containing flue gas emitted from various kilns or reactors in smelting, chemical, and other industries undergoes adiabatic evaporation cooling and dust removal through a purification and scrubbing system before entering the SO2 flue gas absorption tower 1. The flue gas reacts with lean amine liquid flowing from top to bottom on the packing surface through a gas-liquid absorption reaction. After SO2 removal, the flue gas meets ultra-clean emission standards and is then discharged through chimney 36. The SO2-rich amine liquid absorbed in the SO2 flue gas absorption tower 1 is heated to 97°C by the lean-rich amine heat exchanger 2 and then sent to the SO2 desorption tower 3. In the SO2 desorption tower 3, desorption is completed by secondary steam heating generated by a reboiler (heat source: low-pressure steam). The desorbed SO2 saturated gas sequentially enters the condenser 35 and the SO2 vapor-liquid separator 34 to obtain a high-concentration SO2 gas composed of 90% SO2 and 10% water at a temperature of 45°C. This achieves the goal of SO2 gas purification and concentration, solving the problem of removing volatile gases by distillation.

[0069] The high-concentration SO2 gas produced by the SO2 vapor-liquid separator 34 is mixed with the pure O2 replenishment pipe 4 and the N2 returned from the chemical reagent sulfuric acid absorption tower 14 and / or the electronic grade sulfuric acid absorption tower 20 to obtain a SO2-water mixture gas with a temperature of 50℃~90℃. The SO2-water mixture gas has a SO2 concentration of 30% (V / V%), an O2 concentration of 25% (V / V%), and the remainder is N2 and water. The SO2-water mixture gas enters the flue gas drying tower 6 and comes into countercurrent contact with the sprayed 95% dry sulfuric acid. After drying, a SO2-water-free mixture gas with a temperature of 50℃~120℃ is obtained. The SO2-water-free mixture gas is pressurized to 25kPa~40kPa by the SO2 booster fan 7 and then enters the first-stage heat exchanger 8 to exchange heat with the third-stage reformed mixture gas at the first-stage outlet of the multi-stage converter 9. The SO2 first-stage heated mixture gas after heat exchange then enters the second-stage heat exchanger 33 to exchange heat with the second-stage outlet of the multi-stage converter 9. The SO2 mixture undergoes heat exchange, and the SO2 mixture after heat exchange enters the tertiary heat exchanger 32 to exchange heat with the primary conversion mixture from the outlet of the quasi-isothermal pre-converter 31. After three heat exchanges, the temperature of the SO2 conversion mixture reaches 400℃, and then enters the quasi-isothermal pre-converter 31 for primary conversion reaction. The temperature of the primary conversion mixture at the outlet of the quasi-isothermal pre-converter 31 will rise. After heat recovery by the waste heat boiler 30 and cooling to 425℃ by heat exchange in the tertiary heat exchanger 32, it enters the second layer of the multi-stage converter 9. After the reaction in the second layer of the multi-stage converter 9, the temperature of the secondary conversion mixture rises and enters the secondary heat exchanger 33. After heat exchange, the temperature drops to 415℃ and enters the first layer of the multi-stage converter 9 for conversion reaction. The tertiary conversion mixture after the reaction in the first layer of the multi-stage converter 9 enters the primary heat exchanger 8. The SO3 mixture, whose temperature drops to 170℃ after heat exchange, is sent to the fuming sulfuric acid absorption tower 10.

[0070] The fuming sulfuric acid absorption tower 10 completes the fuming sulfuric acid circulation through the fuming sulfuric acid circulation pump 12 and the fuming sulfuric acid cooler 11. The fuming sulfuric acid in the fuming sulfuric acid circulation tank can replenish the consumption in the dry sulfuric acid circulation tank. The fuming sulfuric acid in the fuming sulfuric acid circulation tank is replenished from the chemical reagent sulfuric acid circulation tank and / or the SO3 vaporizer 26. After the SO3 mixture is partially absorbed by the acid in the fuming sulfuric acid absorption tower 10, the remaining SO3 mixture enters the chemical reagent sulfuric acid absorption tower 14 for further absorption. Ultrapure water is added through the ultrapure water inlet pipe 15 to maintain the acid concentration balance. The chemical reagent sulfuric acid absorption tower 14 completes the acid circulation through the chemical reagent sulfuric acid circulation pump 16 and the chemical reagent sulfuric acid cooler 17. At the same time, chemical reagent sulfuric acid (analytical grade sulfuric acid) is produced through the finished chemical reagent sulfuric acid outlet pipe 18. At this time, the total absorption rate of SO3 gas reaches 99.99%, and almost all of the remainder is N2 (the remainder is excess O2), which returns to the circulating gas mixing device 5 to continue gas distribution and complete the closed cycle.

[0071] Fuming sulfuric acid with a SO3 free content of 26% to 32% in the fuming sulfuric acid circulation tank is pressurized to 100 kPa to 150 kPa by the fuming sulfuric acid circulation pump 12, and then sent to SO3 evaporator 29 through fuming sulfuric acid inlet pipe 13. In SO3 evaporator 29, SO3 gas is evaporated by heating to 130°C with low-pressure saturated steam. The atmospheric pressure fuming sulfuric acid with a SO3 free content of 20% to 23% and a temperature of 90°C to 110°C after evaporation in SO3 evaporator 29 returns to the fuming sulfuric acid circulation tank to continue to circulate and absorb SO3 in the SO3 mixture. The SO3 gas evaporated from SO3 evaporator 29 is then removed by a demister to remove trace amounts of sulfuric acid, resulting in high-purity SO3 gas with a purity of over 99.99%.

[0072] High-purity SO3 gas is condensed into liquid SO3 in an SO3 condenser 28 with the temperature controlled at 35℃ and then stored in a liquid SO3 storage tank 27. Since reducing gases such as SO2 have high boiling points, they are still in a gaseous state at this point and return to the circulating gas mixing device 5 through the exhaust pipe. This process completes the SO3 distillation and purification process, and the obtained ultra-pure SO3 liquid has a purity of 99.9999%.

[0073] Ultrapure SO3 liquid is vaporized in SO3 vaporizer 26 to obtain ultrapure SO3 gas. The ultrapure SO3 gas is mixed with ultrapure inert gas to obtain electronic-grade sulfuric acid absorption gas, which enters electronic-grade sulfuric acid absorption tower 20 through ultrapure SO3 gas output pipe 19 for absorption. Ultrapure water is added through electronic-grade ultrapure water input pipe 21 to maintain the acid concentration balance in the electronic-grade sulfuric acid circulation tank. Electronic-grade sulfuric acid absorption tower 20 completes the circulation absorption through electronic-grade sulfuric acid circulation tank, electronic-grade sulfuric acid circulation pump 22, and cluster heat exchanger 23. After circulation absorption, the electronic-grade sulfuric acid passes through filter 24 and electronic-grade sulfuric acid output pipe 25 to produce finished electronic-grade sulfuric acid (reaching E1 and E2 grades), which is transported under nitrogen sealing in storage tanks. The absorption rate of ultrapure SO3 gas in the electronic-grade sulfuric acid circulation absorption process reaches 99.99%. The remaining gas returns to the circulating gas mixing device 5 for further gas distribution to complete the closed-loop cycle.

[0074] The concentration of the obtained electronic-grade sulfuric acid is 92.5% to 98%.

[0075] The above-mentioned device greatly shortens the purification process of electronic-grade sulfuric acid by purifying the raw material gas; at the same time, the gas inside the system can achieve closed-loop circulation, achieving "0" emissions, and can be controlled in a closed and clean environment.

[0076] Verification Example 1

[0077] A lead-acid battery recycling plant has a flue gas volume of approximately 100,000 Nm³. 3 / h, SO2 concentration 12~120g / Nm 3Nitrogen oxides: 400-600 mg / Nm 3 The flue gas temperature is ~80℃, and the flue gas pressure is ~8.0KPa. Based on steps A to F of the process provided by this utility model, combined with the reagent sulfuric acid cyclic absorption, an organic amine desulfurization method is adopted, combined with a dual-tower double-effect + desorption low-pressure variable-load deep desorption process. After organic amine desulfurization, the emission index is: SO2 concentration 35mg / Nm³. 3 Sulfuric acid mist 35 mg / Nm 3 After further purification, high-concentration SO2 gas with a volume concentration of 90% SO2 and a volume concentration of 10% water is obtained. After the high-concentration SO2 gas is introduced into the air (equivalent to oxygen supplementation), the SO2 concentration in the mixed flue gas reaches 18%. The total conversion rate reaches 98% through three-stage conversion. The converted flue gas is cooled to 160℃~130℃ by heat exchange, and after precision filtration, it enters the refined acid absorption tower (steel-lined F4x). Ultrapure water is added to maintain the acid concentration balance. The sulfuric acid produced meets or exceeds the analytical grade index of chemical reagent sulfuric acid.

[0078]

[0079] The device provided by this invention features a simple layout, small footprint, high operating efficiency, and easy management and operation. It achieves the analytical purity of sulfuric acid, a chemical reagent, thus saving investment and reducing production costs. This verification example demonstrates the feasibility of using organic amines for SO2 absorption and desorption purification.

[0080] Verification Example 2

[0081] A large non-ferrous metal smelting enterprise, due to advancements in oxygen-enriched smelting technology, increased metal production in its smelting section by raising oxygen concentrations, resulting in an SO2 concentration of 19.6% in the smelting flue gas. The proposed technical upgrade involved adding an isothermal pre-conversion process. The inlet isothermal pre-conversion flue gas volume was approximately 60,000 Nm³. 3 / h, SO2 concentration 18%, O2 concentration 14%. Isothermal pre-conversion stage, conversion rate ≥90%.

[0082] Although the quasi-isothermal conversion device of this invention has an SO2 concentration as high as 30%, by supplementing with pure oxygen, the oxygen concentration in the flue gas also reaches 30%, and the oxygen-to-sulfur ratio is higher than that of current smelting devices. According to calculations, the first-stage conversion rate of the quasi-isothermal conversion device exceeds 90%, and the total conversion rate of this device is ≥99.6%. This verification example uses pure oxygen in conjunction with isothermal pre-conversion to prove the feasibility of producing acid from high-concentration SO2.

[0083] Verification Example 3

[0084] A chemical company producing chlorosulfonic acid and ketone (K acid) uses pyrite as raw material to produce 10,000 tons of liquid SO3 annually through the evaporation and condensation of fuming sulfuric acid. The production process is continuous and stable. High-purity SO3 is obtained through distillation purification. This verification example demonstrates the feasibility of SO3 distillation as a method.

[0085] Based on the above three verification examples that demonstrate the process feasibility of the device provided by this utility model, this utility model will illustrate the specific usage process of the device for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines through the following embodiments.

[0086] An apparatus for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines, such as... Figure 1 As shown, the process flow steps of this device are as follows:

[0087] A. Flue gas containing SO2 (3.2% SO2 volume concentration) and impurities, along with volatile gases, undergoes adiabatic evaporation cooling and dust removal through a purification and scrubbing system before entering SO2 flue gas absorption tower 1 for gas-liquid absorption reaction. After SO2 removal, the flue gas meets ultra-clean emission standards and is then discharged through chimney 36. The amine-rich liquid, having absorbed SO2 in SO2 flue gas absorption tower 1, is then heated by a lean-amine heat exchanger 2 before entering SO2 desorption tower 3. In SO2 desorption tower 3, the amine-rich liquid undergoes desorption by secondary steam generated by a reboiler, yielding a saturated SO2 gas at 113°C containing pure SO2 and water.

[0088] B. Saturated SO2 gas is first cooled to 50°C by condensation to remove water, and then dehydrated by gas-liquid separation to obtain high-concentration SO2 gas with a volume concentration of 92% SO2 and 8% water.

[0089] C. A mixture of high-concentration SO2 gas, pure O2, and inert gas is obtained to form a SO2-water mixture at a temperature of 50°C. The SO2 volume concentration in the SO2-water mixture reaches 30%, and the O2 volume concentration reaches 29%.

[0090] D. A mixture of SO2 and water is dried using concentrated sulfuric acid with a mass fraction of not less than 93% to obtain a dehydrated SO2 mixture at a temperature of 50℃. The volume concentration of SO2 in the dehydrated SO2 mixture is 31%.

[0091] E. The SO2 dehydration mixture is pressurized to obtain a SO2 pressurized mixture with a pressure of 30 kPa and a temperature of 80℃. This SO2 pressurized mixture undergoes a first-stage heating process to obtain a first-stage heated SO2 mixture with a pressure of 28.5 kPa and a temperature of 300℃. A second-stage heating process yields a second-stage heated SO2 mixture with a pressure of 27.2 kPa and a temperature of 350℃. A third-stage heating process yields a SO2 conversion mixture with a pressure of 26 kPa and a temperature of 400℃. This SO2 conversion mixture undergoes a first-stage conversion process to output a first-stage conversion mixture with a pressure of 24 kPa and a temperature of 500℃. This first-stage conversion mixture undergoes a first-stage cooling process to output a final pressure of 23 kPa and a temperature of... The process involves a first-stage cooling mixture at 440℃; a second-stage reforming mixture at 490℃ and 20.8 kPa; a third-stage cooling mixture at 420℃ and 19 kPa; a fourth-stage cooling mixture at 445℃ and 17 kPa; and finally, a third-stage cooling mixture at 215℃, producing an SO3 mixture. The SO3 mixture consists of SO3, excess O2, inert gases, and trace impurities. The overall SO2 conversion rate after multi-stage reforming reaches 99.5%.

[0092] F. A SO3 mixture with a pressure of 15 kPa and a temperature of 215°C is introduced from the bottom of the fuming sulfuric acid absorption tower 10 and encounters fuming sulfuric acid with a pressure of 120 kPa and a temperature of 52°C flowing downwards. Part of the SO3 is absorbed, generating atmospheric fuming sulfuric acid at a temperature of 65°C. This gas returns to the fuming sulfuric acid circulation tank and is pressurized by the fuming sulfuric acid circulation pump 12 and cooled by the fuming sulfuric acid cooler 11 to a pressure of 120 kPa and a temperature of 52°C, continuing to participate in the circulation absorption. A SO3 mixture with 37% of its SO3 absorbed by the fuming sulfuric acid circulation and containing the remaining SO3, at a pressure of 15 kPa and a temperature of 80°C, is transported to the chemical reagent sulfuric acid absorption tower 14 for further circulation absorption. A SO3 mixture with a pressure of 12 kPa and a temperature of 80°C is introduced from the bottom of the chemical reagent sulfuric acid absorption tower 14 and encounters chemical reagent sulfuric acid with a pressure of 120 kPa and a temperature of 70°C flowing downwards. The remaining SO3 is absorbed, generating atmospheric fuming sulfuric acid at a temperature of 95°C. At 0℃, atmospheric pressure sulfuric acid is returned to the sulfuric acid circulation tank and pressurized by the sulfuric acid circulation pump 16 and cooled by the sulfuric acid cooler 17 to a pressure of 120 kPa and a temperature of 70℃, continuing to participate in the circulation absorption. Meanwhile, the tail gas, composed of excess O2 and inert gas, with a pressure of 9 kPa and a temperature of 75℃, is output from the top of the sulfuric acid absorption tower 14 and returns to step C to continue the circulation. The sulfuric acid circulation tank is replenished with ultrapure water through the ultrapure water inlet pipe 15 to maintain acid concentration balance. The sulfuric acid at 90℃ in the circulation tank is pressurized by the sulfuric acid circulation pump 16 and cooled by the sulfuric acid cooler 17 to a pressure of 120 kPa and a temperature of 70℃, and then output through the finished sulfuric acid outlet pipe 18. The total SO3 absorption rate in the SO3 mixture after absorption by fuming sulfuric acid circulation and sulfuric acid circulation can reach 99.99%.

[0093] G. Fuming sulfuric acid with a SO3 free content of 30% in the fuming sulfuric acid circulation tank is pressurized to 120 kPa by the fuming sulfuric acid circulation pump 12, and then sent to the SO3 evaporator 29 through the fuming sulfuric acid inlet pipe 13. The SO3 evaporator 29, heated by low-pressure steam, evaporates and removes impurities from the fuming sulfuric acid with a SO3 free content of 30%, obtaining SO3 gas with a pressure of 40 kPa and a temperature of 130°C. The fuming sulfuric acid with a SO3 free content of 30% is reduced to atmospheric pressure fuming sulfuric acid with a SO3 free content of 22% and a temperature of 100°C after SO3 evaporation and returned to the fuming sulfuric acid circulation tank. The evaporation process of SO3 evaporator 29 can remove trace heavy metals and dust. The SO3 gas evaporated by SO3 evaporator 29 is purified by a demister to remove trace sulfuric acid, obtaining high-purity SO3 gas with a purity of over 99.99%.

[0094] H. High-purity SO3 gas enters SO3 condenser 28 at 35°C for liquefaction distillation (distillation removes other non-condensable gases based on its different properties from other non-condensable gases), obtaining ultra-pure SO3 liquid with a pressure of 0.3 kPa, a temperature of 35°C, and a purity of over 99.9999%, which is then sent to liquid SO3 storage tank 27 for storage; the gaseous reducing gas (such as SO2 gas) produced by liquefaction distillation returns to the circulating gas mixing device 5 in step C through a valved pipeline installed on SO3 condenser 28 or liquid SO3 storage tank 27.

[0095] 1. Ultrapure SO3 liquid is fed into SO3 vaporizer 26, which has a vaporization temperature of 65℃. SO3 vaporizer 26, which is heated by low-pressure steam, outputs ultrapure SO3 gas with a pressure of 10kPa and a temperature of 65℃. The electronic-grade sulfuric acid absorption gas obtained by mixing ultrapure SO3 gas with ultrapure inert gas is input into electronic-grade sulfuric acid absorption tower 20. The residual liquid produced by SO3 vaporizer 26 is transported to fuming sulfuric acid circulation tank to participate in SO3 absorption.

[0096] J. Electronic-grade sulfuric acid absorption gas is introduced from the bottom of the electronic-grade sulfuric acid absorption tower 20 and encounters electronic-grade sulfuric acid with a pressure of 10 kPa and a temperature of 65°C flowing downwards. The gas is absorbed, generating atmospheric-pressure electronic-grade sulfuric acid at a temperature of 85°C. This gas returns to the electronic-grade sulfuric acid circulation tank and is pressurized by the electronic-grade sulfuric acid circulation pump 22 and cooled by the cluster heat exchanger 23 to a pressure of 120 kPa and a temperature of 65°C, continuing to participate in the circulation absorption. Meanwhile, inert gas with a pressure of 7.5 kPa and a temperature of 70°C is output from the top of the electronic-grade sulfuric acid absorption tower 20 and returns to step C to continue the circulation, resulting in zero tail gas emissions. The electronic-grade sulfuric acid circulation tank is replenished with electronic-grade ultrapure water through the electronic-grade ultrapure water input pipe 21 to maintain acid concentration balance. The purity of the electronic-grade ultrapure water is 99.9999 wt%, and the absorption rate of ultrapure SO3 gas in the electronic-grade sulfuric acid absorption gas can reach 99.99%.

[0097] K. Electronic-grade sulfuric acid is pressurized by electronic-grade sulfuric acid circulation pump 22 and cooled by cluster heat exchanger 23 to a pressure not exceeding 100 kPa and a temperature not exceeding 40°C. It is then sent to filter 24 with a filter membrane pore size of 0.1 μm to 1 μm for three-stage filtration to obtain finished electronic-grade sulfuric acid. The finished electronic-grade sulfuric acid is output to electronic-grade sulfuric acid storage tank for nitrogen sealing through electronic-grade sulfuric acid output pipe 25. The finished electronic-grade sulfuric acid meets the E1 grade in the national standard GB / T41881-2022.

[0098] This invention utilizes a device that evaporates SO3 gas from clean fuming sulfuric acid, achieving a purity several orders of magnitude higher than that of SO3 gas evaporated from industrial-grade fuming sulfuric acid. Further purification via SO3 distillation yields SO3 gas with a purity of 99.9999%. This high-purity SO3 gas is then absorbed by electronic-grade sulfuric acid in a clean environment within an electronic-grade sulfuric acid absorption tower 20 (lined with ultra-pure PTFE and packed with ultra-pure PFA Pall rings) to produce electronic-grade sulfuric acid (E1 and E2 grades). This significantly shortens the time required to reach the required standards, overcoming the problems of long processing times and unstable products associated with other processes. Therefore, it is suitable for widespread application.

[0099] In this embodiment of the invention, the term "multiple" refers to two or more, unless otherwise explicitly defined. The terms "install," "connect," and "fix" should be interpreted broadly. For example, "connect" can mean a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this embodiment of the invention based on the specific circumstances.

[0100] In the description of the embodiments of this utility model, it should be understood that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this utility model and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific direction or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this utility model.

[0101] In this specification, the terms "an embodiment," "a preferred embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0102] The above embodiments are only for illustrating the technical concept of this utility model and should not be construed as limiting the scope of protection of this utility model. Any modifications made to the technical solution based on the technical concept proposed by this utility model shall fall within the scope of protection of this utility model. Technologies not covered by this utility model can be implemented by existing technologies.

Claims

1. An apparatus for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines, characterized in that: The device comprises, in sequence, an organic amine absorption and desorption unit, an SO2 gas concentration unit, a circulating gas mixing unit (5), a drying unit, a quasi-isothermal multi-stage conversion unit, a fuming acid circulating absorption unit, an evaporation and impurity removal unit, a liquefaction distillation unit, a gasification mixing unit, and an electronic-grade sulfuric acid circulating absorption unit. The organic amine absorption and desorption device is used to treat SO2 flue gas containing other components to obtain SO2 saturated gas containing pure SO2 and water, which is then transported to the SO2 gas concentration device. The SO2 gas enrichment device is used to condense and separate SO2 saturated gas into gas and liquid to obtain high-concentration SO2 gas with a volume concentration of 80% to 95%, and then transport it to the circulating gas mixing device (5). The circulating gas mixing device (5) is used to mix high-concentration SO2 gas with pure O2 and inert gas to obtain SO2 water-containing mixed gas with a volume concentration of 7% to 40%, and then transport it to the drying device; the source of inert gas is the inert gas that has not been absorbed by the subsequent device and the newly added inert gas. The drying device uses concentrated sulfuric acid with a mass fraction of not less than 93% to dry the SO2-water mixture to obtain a dehydrated SO2 mixture, which is then transported to a quasi-isothermal multi-stage conversion unit. The quasi-isothermal multi-stage conversion device is used to pressurize and heat the SO2 dehydrated gas mixture and then perform multi-stage conversion to obtain a SO3 mixture containing SO3, excess O2, inert gas and a small amount of impurities, which is then transported to the fuming acid recycling absorption device. The fuming acid circulating absorption device uses fuming sulfuric acid to circulate and absorb SO3 in the SO3 mixture, and obtains fuming sulfuric acid with a free SO3 content of 26% to 32%, which is then transported to the evaporation and impurity removal device. The evaporation and impurity removal device is used to evaporate and remove impurities from fuming sulfuric acid with a SO3 free content of 26% to 32% to obtain high-purity SO3 gas with a purity of over 99.99%, which is then transported to the liquefaction distillation unit. The liquefaction distillation unit is used to liquefy and distill high-purity SO3 gas to obtain ultra-pure SO3 liquid with a purity of over 99.9999%, and then transport it to the gasification mixing unit. The gasification mixing device is used to vaporize ultrapure SO3 liquid into ultrapure SO3 gas, which is then mixed with ultrapure inert gas to obtain electronic-grade sulfuric acid absorption gas, and then transported to the electronic-grade sulfuric acid recycling absorption device. The electronic-grade sulfuric acid recycling absorption device uses electronic-grade sulfuric acid to circulate and absorb SO3 in the gas. The electronic-grade sulfuric acid obtained from the recycling absorption is filtered and then output as finished electronic-grade sulfuric acid.

2. The apparatus for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines according to claim 1, characterized in that: The device also includes a chemical reagent sulfuric acid circulation absorption device, which is connected to the top of the fuming sulfuric acid absorption tower (10) in the fuming acid circulation absorption device via a pipeline. The chemical reagent sulfuric acid circulation absorption device is equipped with a finished chemical reagent sulfuric acid output pipe (18) and is connected to the circulation mixing device (5) via an inert gas circulation pipe.

3. The apparatus for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines according to claim 2, characterized in that: The aforementioned chemical reagent sulfuric acid circulation absorption device includes a chemical reagent sulfuric acid absorption tower (14), a chemical reagent sulfuric acid circulation tank equipped with a chemical reagent sulfuric acid circulation pump (16), and a chemical reagent sulfuric acid cooler (17). The lower part of the chemical reagent sulfuric acid absorption tower (14) is connected to the top of the fuming sulfuric acid absorption tower (10) through a pipe to receive the SO3 mixture carrying the remaining SO3 output from the fuming sulfuric acid absorption tower (10). The bottom of the chemical reagent sulfuric acid absorption tower (14) is connected to the chemical reagent sulfuric acid circulation tank through a pipe, and the chemical reagent sulfuric acid circulation pump (16) in the chemical reagent sulfuric acid circulation tank is connected to the chemical reagent sulfuric acid cooler through a pipe. (17) The chemical reagent sulfuric acid cooler (17) is connected to the liquid distributor above the packing layer in the chemical reagent sulfuric acid absorption tower (14) through a pipe. A demister is also arranged above the liquid distributor in the chemical reagent sulfuric acid absorption tower (14), and the top of the chemical reagent sulfuric acid absorption tower (14) is connected to the circulating gas mixing device (5) through a pipe. A finished chemical reagent sulfuric acid output pipe (18) with a valve is arranged on the pipe between the chemical reagent sulfuric acid cooler (17) and the liquid distributor in the chemical reagent sulfuric acid absorption tower (14). An ultrapure water input pipe (15) is arranged on the chemical reagent sulfuric acid circulation tank to replenish ultrapure water to balance the acid concentration.

4. The apparatus for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines according to any one of claims 1-3, characterized in that: The organic amine absorption and desorption device includes an SO2 flue gas absorption tower (1), a lean and rich amine heat exchanger (2), and an SO2 desorption tower (3). The rich amine liquid output pipe at the bottom of the SO2 flue gas absorption tower (1), which has a chimney (36) at the top, is connected to the liquid distributor above the packing layer in the middle of the SO2 desorption tower (3) via the lean and rich amine heat exchanger (2). The lean amine liquid output pipe at the bottom of the SO2 desorption tower (3) is connected to the liquid distributor above the packing layer in the upper middle of the SO2 flue gas absorption tower (1) via the lean and rich amine heat exchanger (2). The top of the SO2 desorption tower (3) is connected to an SO2 gas enrichment device via a pipe, and the SO2 gas enrichment device is connected to the liquid distributor above the packing layer in the upper middle of the SO2 desorption tower (3) via a return liquid pipe.

5. The apparatus for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines according to any one of claims 1-3, characterized in that: The SO2 gas enrichment device includes an SO2 condenser (35) and an SO2 vapor-liquid separator (34). The SO2 condenser (35) is connected to the top of the SO2 desorption tower (3) in the organic amine absorption and desorption device via a pipeline. The SO2 condenser (35) can condense and cool the SO2 saturated gas, which is pure SO2 and water, output from the SO2 desorption tower (3) to 40℃~80℃ for dehydration. The SO2 condenser (35) is connected to the cavity below the packing layer in the inner cavity of the SO2 vapor-liquid separator (34) via a pipeline. The top of the gas-liquid separator (34) is connected to the circulating gas mixing device (5) through a pipe, and the bottom is connected to the liquid distributor above the packing layer of the SO2 desorption tower (3) in the organic amine absorption and desorption device through a return liquid pipe. The SO2 condenser (35) can separate the dehydrated SO2 saturated gas into a high concentration of SO2 gas with a volume concentration of 80% to 95% and 20% to 5% water, and transport it to the circulating gas mixing device (5). The water obtained from the gas-liquid separation is returned to the organic amine absorption and desorption device through the return liquid pipe.

6. The apparatus for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines according to any one of claims 1-3, characterized in that: The circulating gas mixing device (5) is equipped with a pure oxygen supply pipe (4), an inert gas supply pipe, an inert gas circulation pipe, and a high-concentration SO2 gas delivery pipe. The circulating gas mixing device (5) is connected to the high-concentration SO2 gas outlet of the SO2 vapor-liquid separator (34) in the SO2 gas enrichment device through the high-concentration SO2 gas delivery pipe. The circulating gas mixing device (5) is connected to the drying device through a pipeline to deliver the SO2 water-containing mixed gas to the drying device. The circulating gas mixing device (5) is connected to the electronic-grade sulfuric acid circulating absorption device through the inert gas circulation pipe.

7. The apparatus for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines according to any one of claims 1-3, characterized in that: The drying device includes a flue gas drying tower (6), a sulfuric acid circulating tank equipped with a sulfuric acid circulating pump, and a sulfuric acid cooler. The lower part of the inner cavity of the flue gas drying tower (6) is connected to a circulating gas mixing device (5) through a pipe to receive the SO2 water-containing mixed gas output by the circulating gas mixing device (5). The bottom of the flue gas drying tower (6) is connected to the sulfuric acid circulating tank through a pipe. The sulfuric acid circulating pump in the sulfuric acid circulating tank is connected to the sulfuric acid cooler through a pipe, and the sulfuric acid cooler is connected to the liquid distributor above the packing layer in the flue gas drying tower (6) through a pipe. The top of the flue gas drying tower (6) is connected to a quasi-isothermal multi-stage conversion device through a pipe to output SO2 water-free mixed gas with a SO2 volume concentration of 12% to 40% and a temperature of 50°C to 120°C. The sulfuric acid circulating tank is connected to a fuming sulfuric acid circulating tank and a chemical reagent sulfuric acid circulating tank through a pipe to replenish the sulfuric acid.

8. The apparatus for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines according to any one of claims 1-3, characterized in that: The quasi-isothermal multi-stage conversion device includes an SO2 booster fan (7), a primary heat exchanger (8), a multi-stage converter (9), a quasi-isothermal pre-converter (31), a secondary heat exchanger (33), and a tertiary heat exchanger (32). The SO2 booster fan (7) is connected to the top of the flue gas drying tower (6) in the drying device through a pipeline to receive the SO2-water mixture. The SO2 booster fan (7) passes through the primary heat exchanger (8), the secondary heat exchanger (33), and the tertiary heat exchanger in sequence through the pipeline. (32) is connected to a quasi-isothermal pre-converter (31) equipped with a waste heat boiler (30). The pipe at the bottom of the quasi-isothermal pre-converter (31) is connected to the second layer of the multi-stage converter (9) through a three-stage heat exchanger (32). The pipe at the bottom of the second layer of the multi-stage converter (9) is connected to the first layer of the multi-stage converter (9) through a two-stage heat exchanger (33). The pipe at the bottom of the first layer of the multi-stage converter (9) is connected to the fuming acid circulation absorption device through a first-stage heat exchanger (8) to output SO3 mixed gas.

9. The apparatus for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines according to any one of claims 1-3, characterized in that: The fuming sulfuric acid circulating absorption device includes a fuming sulfuric acid absorption tower (10), a fuming sulfuric acid circulating tank equipped with a fuming sulfuric acid circulating pump (12), and a fuming sulfuric acid cooler (11). The lower part of the fuming sulfuric acid absorption tower (10) is connected to the first-stage heat exchanger (8) in the quasi-isothermal multi-stage conversion device through a pipeline to receive the SO3 mixed gas output from the first-stage heat exchanger (8). The bottom of the fuming sulfuric acid absorption tower (10) is connected to the fuming sulfuric acid circulating tank through a pipeline. The fuming sulfuric acid circulating pump (12) in the fuming sulfuric acid circulating tank is connected to the fuming sulfuric acid circulating tank through a pipeline. The fuming sulfuric acid cooler (11) is connected to the liquid distributor above the packing layer in the fuming sulfuric acid absorption tower (10) via a pipe. A demister is also arranged above the liquid distributor in the fuming sulfuric acid absorption tower (10), and the top of the fuming sulfuric acid absorption tower (10) is connected to the chemical reagent sulfuric acid circulation absorption device via a pipe. The fuming sulfuric acid circulation tank is connected to the chemical reagent sulfuric acid circulation tank and the SO3 vaporizer (26) in the evaporation and impurity removal device via a pipe to replenish the circulating fuming sulfuric acid.

10. The apparatus for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines according to claim 9, characterized in that: The evaporation and impurity removal device includes an evaporator nicotinic acid inlet pipe (13) and an SO3 evaporator (29). The inlet end of the evaporator nicotinic acid inlet pipe (13) with an evaporation valve is located on the pipeline between the fuming sulfuric acid circulation pump (12) and the fuming sulfuric acid cooler (11). The outlet end of the evaporator nicotinic acid inlet pipe (13) is connected to the SO3 evaporator (29), and the SO3 evaporator (29) is connected to the fuming sulfuric acid circulation tank through a return pipe. The SO3 evaporator (29) equipped with low-pressure steam is connected to the liquefaction distillation unit through a pipeline to output high-purity SO3 gas.

11. The apparatus for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines according to any one of claims 1-3, characterized in that: The liquefaction distillation apparatus includes an SO3 condenser (28) and a liquid SO3 storage tank (27). The SO3 condenser (28), with a condensation temperature of 30℃ to 50℃, is connected to the output end of the SO3 evaporator (29) via a pipeline to receive high-purity SO3 gas with a pressure of 20kPa to 50kPa and a temperature of 90℃ to 140℃. The SO3 condenser (28) is connected to the liquid SO3 storage tank (27) via a pipeline to output ultra-pure SO3 liquid with a purity of 99.9999% or higher. The liquid SO3 storage tank (27) is connected to a gasification mixing device via a pipeline. The SO3 condenser (28) and / or the liquid SO3 storage tank (27) are connected to a circulating gas mixing device (5) via a pipeline.

12. The apparatus for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines according to any one of claims 1-3, characterized in that: The vaporization mixing device includes an SO3 vaporizer (26) and an ultrapure SO3 gas output pipe (19). The upper or lower part of the SO3 vaporizer (26), which has a vaporization temperature of 50℃ to 80℃, is connected to the bottom of a liquid SO3 storage tank (27) via a pipe. The SO3 vaporizer (26) can receive ultrapure SO3 liquid with a pressure of 0 kPa to 1 kPa and a temperature of 20℃ to 35℃ output from the liquid SO3 storage tank (27) and vaporize it to output ultrapure SO3 with a pressure of 10 kPa to 15 kPa and a temperature of 60℃ to 80℃. Pure SO3 gas; the top of the SO3 vaporizer (26) is connected to the lower part of the electronic grade sulfuric acid absorption tower (20) in the electronic grade sulfuric acid circulation absorption device through the ultrapure SO3 gas output pipe (19). An ultrapure inert gas input pipe is arranged on the ultrapure SO3 gas output pipe (19). The ultrapure inert gas input pipe is mixed with the ultrapure SO3 gas with a pressure of 10kPa to 15kPa and a temperature of 60℃ to 80℃ in the ultrapure SO3 gas output pipe (19) to obtain electronic grade sulfuric acid absorption gas.

13. The apparatus for producing electronic-grade sulfuric acid based on the absorption and desorption of organic amines according to any one of claims 1-3, characterized in that: The electronic-grade sulfuric acid circulating absorption device includes an electronic-grade sulfuric acid absorption tower (20), an electronic-grade ultrapure water inlet pipe (21), an electronic-grade sulfuric acid circulating pump (22), a cluster heat exchanger (23), a filter (24), and an electronic-grade sulfuric acid outlet pipe (25). The lower part of the electronic-grade sulfuric acid absorption tower (20) is connected to an ultrapure SO3 gas outlet pipe (19) to obtain electronic-grade sulfuric acid absorption gas. The top of the electronic-grade sulfuric acid absorption tower (20) is connected to a circulating gas mixing device (5) through a pipe, and the bottom of the electronic-grade sulfuric acid absorption tower (20) is connected to an electronic-grade sulfuric acid circulating tank through a pipe. The electronic-grade sulfuric acid circulating pump (22) is located in the electronic-grade sulfuric acid circulating tank. The pipeline connects to the cluster heat exchanger (23), and the cluster heat exchanger (23) is connected to the liquid distributor above the packing layer in the electronic-grade sulfuric acid absorption tower (20) via a pipeline. A demister is also arranged above the liquid distributor in the electronic-grade sulfuric acid absorption tower (20). A pipeline with a valve is arranged on the pipeline between the cluster heat exchanger (23) and the liquid distributor in the electronic-grade sulfuric acid absorption tower (20) to the filter (24). The outlet of the filter (24) is connected to the electronic-grade sulfuric acid storage tank via the electronic-grade sulfuric acid output pipe (25). An electronic-grade ultrapure water input pipe (21) is arranged on the electronic-grade sulfuric acid circulation tank to replenish the electronic-grade ultrapure water to balance the acid concentration.

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