Method for producing sulfuric acid with different specifications and concentrations

Abstract

The invention belongs to the technical field of sulfuric acid production, and particularly relates to a method for producing sulfuric acid with different specifications and concentrations. Comprising the following steps: S1, pretreatment of raw materials: pretreating the raw materials, and converting the raw materials into sulfur dioxide furnace gas; s2, sulfur dioxide conversion treatment: introducing the sulfur dioxide furnace gas treated in the step S1 into a converter for conversion treatment, and converting the sulfur dioxide furnace gas into sulfur trioxide furnace gas for later use; s3, sulfur trioxide absorption treatment: introducing the sulfur trioxide furnace gas treated in the step S2 into an absorption tower for absorption blending treatment, and obtaining sulfuric acid products with different concentrations after the absorption blending treatment is completed. Compared with a traditional mode that single-concentration sulfuric acid is produced and then diluted, sulfuric acid of different specifications and concentrations is directly produced, the dilution step and related equipment investment are reduced, and the production cost is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sulfuric acid production, and particularly relates to a method for producing sulfuric acid of different specifications. BACKGROUND

[0002] Sulfuric acid is an important basic chemical raw material and is widely used in many industries, such as fertilizer production, metal smelting, petroleum chemical industry, pharmaceuticals, etc. Different industry application scenarios have different requirements for the concentration specifications of sulfuric acid. For example, in fertilizer production, sulfuric acid with a concentration of 93% to 98% is usually required; in the alkylation reaction of petroleum chemical industry, concentrated sulfuric acid with a concentration of more than 98% or fuming sulfuric acid may be required; and in some metal surface treatment processes, dilute sulfuric acid with a concentration of 20% to 50% may be required.

[0003] At present, the traditional sulfuric acid production process can only produce sulfuric acid of a single concentration or a limited number of concentration specifications. Commonly used contact method for producing sulfuric acid mainly produces concentrated sulfuric acid with a concentration of about 98%. If other concentrations of sulfuric acid are needed, the product concentrated sulfuric acid is usually diluted to achieve the desired concentration. However, this method not only increases the production steps and costs, but also makes it difficult to accurately control the concentration of the diluted sulfuric acid, which can easily lead to unstable product quality. In addition, the traditional production process lacks sufficient flexibility and response capability when the market demand for sulfuric acid of different concentrations changes rapidly, and it cannot adjust the production in a timely manner to meet the diversified market demand.

[0004] Therefore, it is of great practical significance to develop a system and method for producing sulfuric acid of different specifications, which can not only meet the diversified needs of different industries, but also improve the market competitiveness and economic benefits of sulfuric acid production enterprises. SUMMARY

[0005] To solve the above problems, the application provides a method for producing sulfuric acid of different specifications.

[0006] The application provides the following technical solutions:

[0007] The method for producing sulfuric acid of different specifications comprises the following steps:

[0008] S1, raw material pretreatment: pretreating the raw material to convert it into sulfur dioxide furnace gas;

[0009] S2, sulfur dioxide conversion treatment: introducing the sulfur dioxide furnace gas treated in step S1 into a converter for conversion treatment to convert it into sulfur trioxide furnace gas for standby;

[0010] S3, sulfur trioxide absorption treatment: introducing the sulfur trioxide furnace gas treated in step S2 into an absorption tower for absorption and blending treatment, and obtaining sulfuric acid products of different concentrations after the treatment.

[0011] Further, the raw material in step S1 includes at least one of sulfur, pyrite and sulfur-containing gas; the pre-treatment methods of different raw materials are different.

[0012] Further, when the raw material is sulfur, the solid sulfur is heated and melted, and then sent to the incinerator for incineration to convert into sulfur dioxide furnace gas.

[0013] Further, when the raw material is pyrite, it is crushed and sieved, and then sent to the fluidized bed furnace to convert into sulfur dioxide furnace gas.

[0014] Further, when the raw material is sulfur-containing gas, the gas is purified and impurity-removed to convert into sulfur dioxide furnace gas.

[0015] Further, the sulfur dioxide furnace gas in step S2 is first subjected to temperature rising treatment before being introduced into the converter, and the temperature is raised to 400-450 DEG C.

[0016] Further, the converter in step S2 is provided with a vanadium-based catalyst, which can catalyze the reaction of sulfur dioxide and oxygen to generate sulfur trioxide.

[0017] Further, the sulfur trioxide furnace gas in step S3 is first subjected to countercurrent contact with concentrated sulfuric acid to generate high-temperature concentrated sulfuric acid, then subjected to countercurrent contact with fuming sulfuric acid to generate high-concentration fuming sulfuric acid, and finally subjected to countercurrent contact with reagent-grade sulfuric acid to generate high-concentration reagent-grade sulfuric acid.

[0018] Further, the adjustment treatment in step S3 is to adjust the concentration of sulfuric acid products generated by sulfur trioxide furnace gas according to the design requirements of products, and then different concentrations of sulfuric acid products are obtained.

[0019] The technical effects and advantages of the method for producing different specifications and concentrations of sulfuric acid are as follows:

[0020] The method has the advantages of high production flexibility, stable product quality, high overall efficiency, low production cost and the like. Specifically, different specifications and concentrations of sulfuric acid can be produced according to market demand, from low-concentration dilute sulfuric acid to high-concentration concentrated sulfuric acid, fuming sulfuric acid and reagent-grade sulfuric acid, to meet the diversified needs of multiple industries. By setting a sulfuric acid blending unit and an online concentration monitor, the concentration of the blended sulfuric acid can be accurately controlled to ensure the stability and consistency of the product quality and improve the market competitiveness of the product. The entire production process is highly automated, and the processes are closely coordinated to reduce manual intervention and production time and improve the production efficiency of sulfuric acid. Compared with the traditional method of producing single-concentration sulfuric acid and then diluting it, the present application directly produces sulfuric acid of different specifications and concentrations, reduces the dilution step and related equipment investment, and reduces the production cost. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0022] Embodiment 1

[0023] The method for producing sulfuric acid of different specifications and concentrations comprises the following steps:

[0024] S1, raw material pretreatment: pretreating the raw material to convert it into sulfur dioxide furnace gas;

[0025] S2, sulfur dioxide conversion treatment: introducing the sulfur dioxide furnace gas treated in step S1 into a converter for conversion treatment to convert it into sulfur trioxide furnace gas for standby;

[0026] S3, sulfur trioxide absorption treatment: introducing the sulfur trioxide furnace gas treated in step S2 into an absorption tower for absorption and blending treatment, and obtaining sulfuric acid products of different concentrations after completion.

[0027] The raw material in step S1 is specifically sulfur, which is first heated to 130-150 DEG C for melting, and then sent to an incinerator for incineration. The temperature of the incinerator is controlled at 1000-1200 DEG C, and the sulfur is fully mixed and burned with air to convert it into sulfur dioxide furnace gas. The concentration of sulfur dioxide in the furnace gas is 8-12%.

[0028] The sulfur dioxide furnace gas in step S2 is first subjected to temperature rising treatment before being introduced into the converter, and its temperature is raised to 400-450 DEG C.

[0029] The converter in step S2 is provided with a vanadium-based catalyst which can catalyze the reaction of sulfur dioxide and oxygen to generate sulfur trioxide. The conversion is generally divided into three stages: the first stage conversion temperature is controlled at 450-480°C, and the conversion rate reaches 70-80%; the converted gas is cooled to 400-420°C by a heat exchanger and then enters the second stage conversion, the second stage conversion temperature is controlled at 420-450°C, and the conversion rate reaches 90-95%; and then the gas is cooled by a heat exchanger and enters the third stage conversion, the third stage conversion temperature is controlled at 400-420°C, so that the total conversion rate reaches more than 99%.

[0030] After the sulfur trioxide furnace gas in step S3 is introduced into the absorption tower, it is first contacted with concentrated sulfuric acid with a concentration of 98.5-99% and a temperature of 170-180°C in countercurrent to generate high-temperature concentrated sulfuric acid with a concentration of 99-99.5%, then the unreacted sulfur trioxide furnace gas is contacted with fuming sulfuric acid with a concentration of 104-105% and a temperature of 50-60°C in countercurrent to generate high-concentration fuming sulfuric acid with a concentration of 106-107%, and finally the unreacted sulfur trioxide furnace gas is contacted with reagent-grade sulfuric acid with a concentration of 98-98.2% and a temperature of 60-70°C in countercurrent to generate high-concentration reagent-grade sulfuric acid with a concentration of 98.8-99%.

[0031] The adjustment process in step S3 is to adjust the concentration of sulfuric acid products generated from sulfur trioxide furnace gas according to the design needs of products, and to obtain sulfuric acid products with different concentrations by real-time monitoring of sulfuric acid concentration by an online concentration monitor.

[0032] The absorption equipment and medium used in the above embodiment 1 are as follows:

[0033] Equipment: FRP material dilute sulfuric acid absorption tower (diameter 2 m, height 10 m, with corrugated filler inside), matched with online concentration meter (accuracy ± 0.1%) and temperature sensor.

[0034] Absorption medium: deionized water (conductivity ≤ 10 μS / cm), stored in a 10 m 3 pure water storage tank.

[0035] Key parameter control:

[0036] Absorption temperature: the circulating liquid temperature is controlled at 35-38°C by a cooling tower to avoid the decrease of SO3 absorption efficiency caused by too high temperature.

[0037] Circulating liquid flow rate: adjust the circulating pump flow rate to stabilize the deionized water flow rate at 1.1 m / s to ensure sufficient contact with SO3 gas.

[0038] Feeding and leading out: slowly introduce deionized water (initial amount 3 m 3 ) into the absorption tower, and at the same time introduce the converted SO3 Gas (flow rate 80 m 3 / h); real-time monitoring by online concentration meter, when the circulating liquid concentration rises to 25%, open the discharge valve to introduce the product at a flow rate of 2 m 3 / h, while supplementing deionized water to maintain the circulating liquid volume stable, finally obtaining 25% dilute sulfuric acid product.

[0039] The product quality corresponding to the above process: 25% dilute sulfuric acid impurity content (Fe 3+ ≤ 0.001%), concentration fluctuation ±0.2%, meeting the GB / T 534-2014 industrial sulfuric acid standard.

[0040] Tail gas treatment: the tail gas of the absorption tower is treated by a 10% NaOH alkali washing tower (flow rate 2 m 3 / h), SO2 emission concentration ≤ 45 mg / m 3 , meeting the environmental protection requirements.

[0041] Example 2

[0042] The method for producing different specifications of sulfuric acid includes the following steps:

[0043] S1, raw material pretreatment: pretreating the raw material to convert it into sulfur dioxide furnace gas;

[0044] S2, sulfur dioxide conversion treatment: introducing the sulfur dioxide furnace gas treated in step S1 into a converter for conversion treatment to convert it into sulfur trioxide furnace gas for standby;

[0045] S3, sulfur trioxide absorption treatment: introducing the sulfur trioxide furnace gas treated in step S2 into an absorption tower for absorption and blending treatment, and obtaining different concentrations of sulfuric acid products after completion.

[0046] The raw material in step S1 is specifically

[0047] Pyrite, which is crushed to a particle size of less than 3 mm and then sent to a fluidized bed furnace for roasting at 850-950℃ to convert it into sulfur dioxide furnace gas.

[0048] The sulfur dioxide furnace gas in step S2 is first subjected to temperature raising treatment before being introduced into the converter, and its temperature is raised to 400-450℃.

[0049] The converter in step S2 is provided with a vanadium-based catalyst which can catalyze the reaction of sulfur dioxide and oxygen to generate sulfur trioxide. The conversion is generally divided into three stages: the first stage conversion temperature is controlled at 450-480°C, and the conversion rate reaches 70-80%; the converted gas is cooled to 400-420°C by a heat exchanger and then enters the second stage conversion, the second stage conversion temperature is controlled at 420-450°C, and the conversion rate reaches 90-95%; and then the gas is cooled by a heat exchanger and enters the third stage conversion, the third stage conversion temperature is controlled at 400-420°C, so that the total conversion rate reaches more than 99%.

[0050] After the sulfur trioxide furnace gas in step S3 is introduced into the absorption tower, it is first contacted with concentrated sulfuric acid with a concentration of 98.5-99% and a temperature of 170-180°C in countercurrent to generate high-temperature concentrated sulfuric acid with a concentration of 99-99.5%, then the unreacted sulfur trioxide furnace gas is contacted with fuming sulfuric acid with a concentration of 104-105% and a temperature of 50-60°C in countercurrent to generate high-concentration fuming sulfuric acid with a concentration of 106-107%, and finally the unreacted sulfur trioxide furnace gas is contacted with reagent-grade sulfuric acid with a concentration of 98-98.2% and a temperature of 60-70°C in countercurrent to generate high-concentration reagent-grade sulfuric acid with a concentration of 98.8-99%.

[0051] The adjustment treatment in step S3 is to adjust the concentration of the sulfuric acid product generated from the sulfur trioxide furnace gas according to the design needs of the product, and the concentration of the sulfuric acid product is monitored in real time by using an online concentration monitor, so as to obtain sulfuric acid products with different concentrations.

[0052] The absorption equipment and medium used in the above example 2 are as follows:

[0053] Equipment: the FRP absorption tower in example 1 is replaced with an online concentration meter with a measurement range of 0-100%.

[0054] Absorption medium: 25% dilute sulfuric acid produced in example 1, stored in a 20 m 3 intermediate storage tank.

[0055] Key parameter control:

[0056] Absorption temperature: the temperature of the circulating liquid is controlled at 40-42°C by a heat exchanger to balance the absorption efficiency and energy consumption.

[0057] Circulating liquid flow rate: the flow rate of the circulating pump is adjusted to stabilize the flow rate of the 25% dilute sulfuric acid at 1.3 m / s.

[0058] Feeding and leading out: 25% dilute sulfuric acid (initially added amount of 4 m 3 ) is added to the absorption tower, and SO3 gas (flow rate of 90 m 3 / h) is introduced; when the online concentration meter shows that the concentration of the circulating liquid rises to 60%, the flow rate of the circulating pump is adjusted to 3 m3 The flow of product H is led out, and 25% dilute sulfuric acid is added synchronously to maintain the dynamic balance of the concentration of circulating liquid.

[0059] Quality verification: product concentration 60.0% ± 0.3%, density 1.49 g / cm 3 (20℃), impurity content meets the use requirements of industrial-grade concentrated sulfuric acid, and can be directly used in the dye synthesis process.

[0060] Example 3

[0061] The method for producing different specifications of concentrated sulfuric acid comprises the following steps:

[0062] S1, raw material pretreatment: the raw material is pretreated to convert it into sulfur dioxide furnace gas;

[0063] S2, sulfur dioxide conversion treatment: the sulfur dioxide furnace gas treated in step S1 is introduced into a converter for conversion treatment to convert it into sulfur trioxide furnace gas for standby;

[0064] S3, sulfur trioxide absorption treatment: the sulfur trioxide furnace gas treated in step S2 is introduced into an absorption tower for absorption and blending treatment, and different concentrations of sulfuric acid products are obtained after completion.

[0065] The raw material in step S1 is specifically sulfur-containing gas (smelting flue gas or sulfur-containing hydrogen sulfide acid gas), which is purified and impurity-removed to convert it into sulfur dioxide furnace gas.

[0066] The sulfur dioxide furnace gas in step S2 is first subjected to temperature rising treatment before being introduced into the converter, and its temperature is first raised to 400-450℃.

[0067] The converter in step S2 is provided with a vanadium-based catalyst, which can catalyze the reaction of sulfur dioxide with oxygen to generate sulfur trioxide. The conversion stage is generally divided into three stages: the first stage conversion temperature is controlled at 450-480℃, and the conversion rate reaches 70-80%; the converted gas is cooled to 400-420℃ by a heat exchanger before entering the second stage conversion, the second stage conversion temperature is controlled at 420-450℃, and the conversion rate reaches 90-95%; and after being cooled by a heat exchanger, it enters the third stage conversion, the third stage conversion temperature is controlled at 400-420℃, so that the total conversion rate reaches more than 99%.

[0068] The sulfur trioxide furnace gas introduced into the absorption tower in step S3 is first contacted with concentrated sulfuric acid with a concentration of 98.5-99% and a temperature of 170-180°C in countercurrent, to generate high-temperature concentrated sulfuric acid with a concentration of 99-99.5%, the unreacted sulfur trioxide furnace gas is then contacted with fuming sulfuric acid with a concentration of 104-105% and a temperature of 50-60°C in countercurrent, to generate high-concentration fuming sulfuric acid with a concentration of 106-107%, and finally the unreacted sulfur trioxide furnace gas is contacted with reagent-grade sulfuric acid with a concentration of 98-98.2% and a temperature of 60-70°C in countercurrent, to generate high-concentration reagent-grade sulfuric acid with a concentration of 98.8-99%.

[0069] The blending treatment in step S3 is to adjust the concentration of the sulfuric acid product generated by the sulfur trioxide furnace gas according to the design requirements of the product, and the concentration of the sulfuric acid is monitored in real time by using an online concentration monitor, so as to obtain sulfuric acid products with different concentrations.

[0070] The absorption equipment and medium of the above embodiment 3 are as follows:

[0071] Equipment: carbon steel lined lead absorption tower (diameter 1.8 m, height 12 m, with built-in grid packing), matched with acid-resistant online concentration meter and temperature interlocking device.

[0072] Absorption medium: 93% concentrated sulfuric acid (purchased, purity 99.9%), stored in a 30 m 3 long carbon steel storage tank.

[0073] Key parameter control:

[0074] Absorption temperature: the temperature of the circulating liquid is controlled at 50-55°C by the disc-type cooler, to avoid the corrosion of the lead lining layer caused by the temperature exceeding 60°C.

[0075] Circulating liquid flow rate: the flow rate of the 93% concentrated sulfuric acid is adjusted to be stable at 1.8 m / s by adjusting the circulating pump flow, to ensure the sufficient absorption of SO3.

[0076] Feeding and leading out: initially, 93% concentrated sulfuric acid (5 m 3 ) is added to the absorption tower, and high-concentration SO3 gas (flow rate 100 m 3 / h, volume fraction 22%) is introduced; when the concentration rises to 98%, 98% concentrated sulfuric acid product is led out at a flow rate of 4 m 3 / h, and 93% concentrated sulfuric acid is supplemented at a flow rate of 2 m 3 / h, to maintain the stability of the circulating liquid volume and concentration.

[0077] Core indicators:

[0078] The product concentration is 98.0% ± 0.2%, the free SO3 content is less than or equal to 0.1%, which meets the concentrated sulfuric acid standard for chemical fertilizer production; the energy consumption of each ton of product is reduced by 6.2% compared with the traditional process, and there is no equipment leakage phenomenon.

[0079] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

[0080] Finally: the above is only a preferred embodiment of the present application and is not used to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for producing sulfuric acid of different concentrations, characterized in that, Includes the following steps: S1. Raw material pretreatment: Pretreatment of raw materials to convert them into sulfur dioxide furnace gas; S2, sulfur dioxide conversion treatment: The sulfur dioxide furnace gas after step S1 is introduced into the converter for conversion treatment, and converted into sulfur trioxide furnace gas for later use. S3. Sulfur trioxide absorption and treatment: The sulfur trioxide furnace gas after step S2 is introduced into the absorption tower for absorption and conditioning treatment, and sulfuric acid products of different concentrations are obtained after completion.

2. The method for producing sulfuric acid of different concentrations according to claim 1, characterized in that, The raw materials mentioned in step S1 include at least one of sulfur, pyrite, and sulfur-containing gas; different raw materials require different pretreatment methods.

3. The method for producing sulfuric acid of different concentrations according to claim 2, characterized in that, When the raw material is sulfur, solid sulfur is heated and melted, and then sent to an incinerator for combustion to convert it into sulfur dioxide gas.

4. The method for producing sulfuric acid of different concentrations according to claim 2, characterized in that, When the raw material is pyrite, it is crushed, screened, and then fed into a fluidized bed furnace to be converted into sulfur dioxide furnace gas.

5. The method for producing sulfuric acid of different concentrations according to claim 2, characterized in that, When the raw material is a sulfur-containing gas, the gas is purified and impurities are removed to convert it into sulfur dioxide furnace gas.

6. The method for producing sulfuric acid of different concentrations according to claim 1, characterized in that, Before the sulfur dioxide furnace gas mentioned in step S2 is introduced into the converter, it is first heated to 400-450℃.

7. The method for producing sulfuric acid of different concentrations according to claim 6, characterized in that, The converter described in step S2 is equipped with a vanadium-based catalyst, which can catalyze the reaction of sulfur dioxide and oxygen to produce sulfur trioxide.

8. The method for producing sulfuric acid of different concentrations according to claim 1, characterized in that, In step S3, the sulfur trioxide furnace gas is introduced into the absorption tower and first comes into countercurrent contact with concentrated sulfuric acid to generate high-temperature concentrated sulfuric acid. The unreacted sulfur trioxide furnace gas then comes into countercurrent contact with fuming sulfuric acid to generate high-concentration fuming sulfuric acid. Finally, the unreacted sulfur trioxide furnace gas comes into countercurrent contact with reagent-grade sulfuric acid to generate high-concentration reagent-grade sulfuric acid.

9. The method for producing sulfuric acid of different concentrations according to claim 1, characterized in that, The blending process described in step S3 involves adjusting the concentration of sulfuric acid products generated from sulfur trioxide furnace gas by using an online concentration monitor to monitor the sulfuric acid concentration in real time according to the product design requirements, thereby obtaining sulfuric acid products of different concentrations.