Device for preparing concentrated sulfuric acid from desulfurization concentrated solution

Abstract

The utility model discloses a device for preparing concentrated sulfuric acid from a desulfurization concentrated solution. The multiphase separator is used for receiving sulfur foam concentrate, the purification tower and the oxidation tower are connected with the multiphase separator, the clarifying tank is connected with the oxidation tower, the dissolving kettle is connected with the clarifying tank, the incinerator is connected with the purification tower, the acid making system is connected with the incinerator, and the dissolving kettle is connected with the incinerator. The device for preparing the concentrated sulfuric acid from the desulfurized concentrated solution disclosed by the utility model is low in one-time investment, environment-friendly, good in comprehensive use effect and capable of reducing energy consumption.

Description

Technical Field

[0001] The utility model belongs to the technical field of waste resource utilization, and specifically relates to a device for preparing concentrated sulfuric acid from desulfurized concentrated liquid. Background Art

[0002] Coke oven gas, as an important by-product of the coking industry, has important significance in environmental protection and energy utilization due to its purification technology. With the increasing attention paid to environmental protection and the continuous growth of energy demand, how to purify coke oven gas efficiently and environmentally friendly and improve its application value has become a core research topic in this field.

[0003] In recent years, coke oven gas purification technology has received extensive attention and research. From basic purification processes to new desulfurization and denitrification technologies, various technologies and methods are constantly being explored and improved. Among them, some studies focus on energy-saving measures in the coke oven gas purification process, aiming to achieve efficient use of resources; while others explore the environmental upgrading and transformation of the coke oven gas deep purification and regeneration system in order to achieve higher environmental protection standards.

[0004] Coke oven gas purification is an important link in the metallurgical industry, which is related to the quality and production efficiency of coking products. In recent years, with the improvement of environmental protection requirements and the optimization of energy utilization, coke oven gas purification technology has been widely studied and applied.

[0005] From the perspective of recent research, the application and improvement of coke oven gas purification technology has become a hot topic. Many papers have discussed different purification processes, equipment selection and energy-saving measures. Among them, dry purification devices, cyclone separators, composite steel plates, etc. have shown good results in practical applications. At the same time, new technologies such as laser gas analysis systems and temperature swing adsorption have also been introduced into coke oven gas purification, providing new ideas for improving purification efficiency and quality.

[0006] Coke oven gas desulfurization and regeneration is an important part of environmental protection engineering. The main purpose is to remove sulfides in the gas to reduce environmental pollution and improve the utilization efficiency of the gas. Research in this field mainly focuses on the development of desulfurization technology, optimization of desulfurization equipment and evaluation of desulfurization effects.

[0007] As the core link of coke oven gas purification, desulfurization technology has also received widespread attention. New desulfurization technologies such as various deep purification and desulfurization processes not only improve the desulfurization efficiency, but also reduce environmental pollution. In addition, extracting hydrogen for hydrogen fuel cells is also a new direction for coke oven gas purification, which provides strong support for the development of green energy. However, despite a lot of progress in coke oven gas purification technology, it still faces some challenges. How to further improve purification efficiency, reduce energy consumption, and reduce environmental pollution remains the focus of research. At the same time, with the improvement of the recovery rate of coking products, how to better utilize coke oven gas resources is also a direction worth exploring.

[0008] The Chinese patent with publication number CN106276973A discloses a distributed resource system and method for sulfur in the coking industry. The invention is based on the resource balance of the coking process system, gives full play to the self-purification function of the coking process, and considers the coupling treatment of sulfur foam, sulfur-containing waste gas and sulfur-containing waste liquid in the system, turning waste into treasure and improving the process value of resources. The technical scheme is: after the sulfur foam is purified, pure sulfur is obtained by incineration to produce acid, and the obtained concentrated sulfuric acid absorbs ammonia in the coke oven gas to produce ammonium sulfate; after decolorization, the desulfurized waste liquid is subjected to thiooxidation, sulfur is separated for incineration to produce acid, and the solution is crystallized and separated to obtain ammonium sulfate and ammonium thiocyanate mother liquor, and the ammonium thiocyanate mother liquor is incinerated to produce SO2, which is absorbed by ammonia water to generate ammonium sulfite, and the ammonium sulfite is oxidized to produce ammonium sulfate or ammonium sulfite is used as a denitrification agent for flue gas denitrification; after the coke oven flue gas recovers the waste heat, it is mixed with ozone to partially or completely oxidize the NO therein, and then desulfurized and denitrified together with the tail gas of the aforementioned resource recovery process, and finally ammonium sulfate and ammonium nitrate are generated.

[0009] This method makes comprehensive use of sulfur in coal gas and has high recovery efficiency, but the overall process is long and complicated, the one-time investment in equipment is high, and the subsequent operating costs remain high, making it difficult to truly promote its use. At the same time, this method incinerates the ammonium thiocyanate mother liquor, resulting in resource loss.

[0010] A Chinese patent with publication number CN106430116A discloses a method for preparing sulfuric acid from sulfur-containing waste liquid produced by coal gas wet oxidation, which comprises the following steps: (1) pretreatment of sulfur-containing waste liquid, (2) incineration of sulfur-containing waste liquid, (3) waste heat recovery, (4) wet purification, (5) drying, (6) dry contact catalytic oxidation, (7) absorption, and (8) tail gas detoxification treatment. The sulfuric acid produced by the method provided by the invention can be supplied to the ammonium sulfate production section as a raw material for ammonium sulfate products. Compared with the existing process, this method is a "clean production" process that does not produce waste liquid, can completely solve the pollution problem of coking desulfurization waste liquid, and meets environmental protection requirements, and has great environmental benefits, social benefits and economic benefits.

[0011] This method can produce high-concentration finished acid, but all desulfurization waste liquid is incinerated, resulting in the loss of ammonium thiocyanate resources and increasing the energy consumption required for incineration. Utility Model Content

[0012] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a device for preparing concentrated sulfuric acid from desulfurized concentrated liquid, the purpose of which is to reduce energy consumption.

[0013] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a device for preparing concentrated sulfuric acid from desulfurized concentrated liquid, including a multi-phase separator for receiving sulfur foam concentrated liquid, a purification tower and an oxidation tower connected to the multi-phase separator, a clarification tank connected to the oxidation tower, a dissolving kettle connected to the clarification tank, an incinerator connected to the purification tower and an acid-making system connected to the incinerator, and the dissolving kettle is connected to the incinerator.

[0014] The acid-making system comprises a waste heat boiler connected to the incinerator, a purification and drying device connected to the waste heat boiler, a conversion tower connected to the purification and drying device, and an absorption tower connected to the conversion tower.

[0015] The clarification tank is connected to a clear liquid cooler, and the clear liquid cooler is connected to a desulfurization unit.

[0016] A stirrer is arranged on the dissolving kettle.

[0017] The dissolving kettle is connected to a quantitative feeding device, the quantitative feeding device is connected to a crude ammonium sulfate hopper, and the crude ammonium sulfate hopper is filled with crude ammonium sulfate crystals.

[0018] The clarification tank is connected to the salt extraction unit.

[0019] The utility model discloses a device for preparing concentrated sulfuric acid from desulfurized concentrated liquid, which has low one-time investment, is environmentally friendly, has good comprehensive use effect, and can reduce energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] This specification includes the following drawings, which show the following contents:

[0021] Figure 1 It is a schematic diagram of the structure of the device for preparing concentrated sulfuric acid from desulfurized concentrated liquid of the utility model;

[0022] The markings in the figure are: 1. multiphase separator; 2. purification tower; 3. oxidation tower; 4. clarification tank; 5. dissolution kettle; 6. incinerator; 7. waste heat boiler; 8. purification and drying device; 9. conversion tower; 10. absorption tower; 11. clear liquid cooler; 12. mixer; 13. quantitative feeding device; 14. crude ammonium sulfate hopper. DETAILED DESCRIPTION

[0023] The specific implementation methods of the utility model are further explained in detail below with reference to the accompanying drawings through the description of embodiments, with the aim of helping technicians in the field to have a more complete, accurate and in-depth understanding of the concept and technical solution of the utility model and facilitating its implementation.

[0024] like Figure 1 As shown, the utility model provides a device for preparing concentrated sulfuric acid from desulfurized concentrated liquid, comprising a multiphase separator 1 for receiving sulfur foam concentrated liquid, a purification tower 2 and an oxidation tower 3 connected to the multiphase separator 1, a clarification tank 4 connected to the oxidation tower 3, a dissolving kettle 5 connected to the clarification tank 4, an incinerator 6 connected to the purification tower 2, and an acid-making system connected to the incinerator 6.

[0025] Specifically, the utility model mainly proposes a plan for the comprehensive utilization of the desulfurization concentrated liquid produced by desulfurization, that is, the concentrated liquid is further concentrated and purified, burned and catalytically oxidized to produce concentrated sulfuric acid, and the concentrated sulfuric acid can react with ammonia to produce ammonium sulfate, thereby achieving comprehensive product recycling and reducing emissions.

[0026] like Figure 1 As shown, the sulfur foam concentrate from the system is physically removed from the liquid sulfur and the clear liquid by entering the multiphase separator 1, and the clear liquid then enters the oxidation tower 3 to further remove the oxidizable impurities. After the impurities are removed, the clear liquid is passed into the storage tank for clarification and separation. The lower impurities are then pumped into the desulfurization system. The upper clear liquid dissolves the crude ammonium sulfate from the salt extraction section to form a desulfurization concentrate, which enters the incinerator 6 for combustion and then undergoes catalytic oxidation to produce concentrated sulfuric acid.

[0027] The multiphase separator 1 is connected to a sulfur foam pretreatment system, which is used to obtain a sulfur foam concentrate after pretreatment, filtration and other steps of the desulfurization liquid and the sulfur foam. The sulfur foam pretreatment system includes a sulfur foam tank, a filter, and a sulfur foam concentrate storage tank. The sulfur foam pretreatment system is used to pass the desulfurization liquid containing sulfur foam through the sulfur foam tank, the filter, and the sulfur foam concentrate storage tank, and then send the sulfur foam concentrate to the multiphase separator 1 through a sulfur foam pump.

[0028] Therefore, the sulfur foam concentrate (sulfur content of about 10-15%) from the sulfur foam pretreatment section (mainly concentrated by filter) can be directly introduced into the multi-phase separator 1 .

[0029] As a modified implementation scheme, in the sulfur foam pretreatment system, a super centrifuge (super centrifuge replaces the filter) can be used to concentrate the sulfur foam, and the sulfur foam concentrate (sulfur content is about 40-55%) directly enters the multi-phase separator 1.

[0030] The sulfur foam concentrate is separated into sulfur and clear liquid at 125-135° C. and 0.25-0.3 MPa (top temperature and top pressure of the multiphase separator 1 ) in the multiphase separator 1 . Steam heating is adopted in the multiphase separator 1 to heat the temperature of the sulfur foam concentrate to the required conditions. The clear liquid in the upper layer of the multiphase separator 1 enters the oxidation tower 3 for purification, and the mixture of liquid sulfur and sulfur slag in the lower layer of the multiphase separator 1 enters the purification tower 2 .

[0031] The liquid sulfur obtained from the purification tower 2 is directly fed into the incinerator 6 for combustion, and the sulfur slag is discharged to the coal yard for coal blending. Specifically, the purification tower 2 is maintained at 140-150°C and 0.5MPa for filtration and separation, and the sulfur slag (mainly composed of tar coal powder and heavy metals, etc.) is discharged from the top of the purification tower 2 and sent to the coal yard of the coking plant, and the liquid sulfur enters the incineration process through self-pressure (controlled at 0.1-0.3MPa).

[0032] The oxidation tower 3 can decompose the oxidizable salts such as ammonium thiosulfate in the supernatant, and the sulfur slag at the bottom after decomposition is discharged to the coal yard for coal blending. The remaining clear liquid is directly discharged into the clarification tank 4.

[0033] like Figure 1 As shown, further, a part of the clear liquid in the clarification tank 4 is sent to the dissolution kettle 5. Another part of the clear liquid in the clarification tank 4 is sent to the salt extraction section, and the clarification tank 4 is connected to the salt extraction unit for extracting ammonium thiocyanate and crude ammonium sulfate.

[0034] like Figure 1 As shown, further, the remaining clear liquid in the clarification tank 4 is discharged to the clear liquid cooler 11, the clarification tank 4 is connected to the clear liquid cooler 11, the clear liquid cooler 11 is connected to the desulfurization unit, and the clear liquid is cooled to 30-40°C and then returned to the desulfurization section.

[0035] like Figure 1 As shown, a stirrer 12 is provided on the dissolving kettle 5. A portion of the clear liquid in the clarification tank 4 is sent to the dissolving kettle 5 with the stirrer 12, and a crude ammonium sulfate hopper 14 is provided on the upper part of the dissolving kettle 5, and the bagged or bulk crude ammonium sulfate crystals produced by the desulfurization and salt extraction unit are added to the crude ammonium sulfate hopper 14.

[0036] The lower part of the crude ammonium sulfate hopper 14 is provided with a quantitative feeding device 13, which can add a quantitative amount of crude ammonium sulfate to the dissolving kettle 5, so that the secondary salt content of the desulfurization concentrated solution in the dissolving kettle 5 reaches 800-850g / l (mainly ammonium sulfate, ammonium thiocyanate and a small amount of ammonium thiosulfate). The temperature of the desulfurization concentrated solution in the dissolving kettle 5 is maintained at 80-95°C to prevent crystal precipitation in the concentrated solution.

[0037] like Figure 1As shown, the dissolving kettle 5 is connected to the incinerator 6. The qualified desulfurized concentrated liquid prepared in the dissolving kettle 5 is sent to the incinerator 6 and incinerated together with the liquid sulfur from the purification tower 2 to generate furnace gas containing sulfur dioxide.

[0038] like Figure 1 As shown, the purified liquid sulfur and desulfurized concentrated liquid enter the incinerator 6 to burn and generate sulfur dioxide. The liquid sulfur and desulfurized concentrated liquid are respectively atomized by compressed air through the atomizing nozzle and enter the incinerator 6 for combustion. Coal gas combustion can be used to provide sufficient heat to burn the liquid sulfur and desulfurized waste liquid concentrated liquid to generate sulfur dioxide. If the amount of liquid sulfur and desulfurized waste liquid concentrated liquid entering the incinerator 6 is sufficient to make the furnace temperature reach 1050°C, coal gas combustion can also be omitted.

[0039] like Figure 1 As shown, the acid production system includes a waste heat boiler 7 connected to the incinerator 6, a purification and drying device 8 connected to the waste heat boiler 7, a conversion tower 9 connected to the purification and drying device 8, and an absorption tower 10 connected to the conversion tower 9.

[0040] The total amount of high-temperature sulfur dioxide gas and water vapor is large and the temperature is high, so it is necessary to recover heat in time. The waste heat boiler 7 is used to recover this part of the heat to generate steam. After the waste heat boiler 7 recovers the waste heat and the temperature drops to about 320°C, the furnace gas enters the purification and drying device 8, and the sulfur dioxide gas is purified and dried by the purification and drying device 8. The obtained sulfur dioxide gas has a high water content and needs to be dried, otherwise it will have an adverse effect on the conversion catalyst. Sulfur dioxide is catalytically oxidized to sulfur trioxide, and sulfur dioxide is converted into sulfur trioxide in the conversion tower 9 at 420°C under the action of the catalyst. Finally, the sulfur trioxide is absorbed by concentrated sulfuric acid in the absorption tower 10 to generate concentrated sulfuric acid product.

[0041] The device for preparing concentrated sulfuric acid from desulfurized concentrated liquid of the above structure has the following advantages:

[0042] 1. Save the heat of converting sulfur foam liquid into sulfur at high temperature.

[0043] If the sulfur foam liquid is directly converted into sulfur through a sulfur melting kettle according to the existing sulfur melting process, a large amount of heat is consumed. After the sulfur foam liquid is concentrated by filtering or other methods, the energy consumption of the multi-phase separator 1 can be reduced, and the load and capacity of the multi-phase separator 1 can be reduced.

[0044] 2. Dry catalytic oxidation of sulfur dioxide. The utility model adopts dry catalytic oxidation of sulfur dioxide, which can directly produce concentrated sulfuric acid with high catalytic efficiency.

[0045] 3. The clear liquid with a higher temperature of nearly 100°C in the clarification tank 4 is directly used to enter the salt extraction section, which can reduce the energy consumption of the salt extraction unit. The clear liquid with a higher temperature of nearly 100°C in the clarification tank 4 is used to dissolve crude ammonium sulfate, which can reduce the steam consumption required to dissolve high-concentration crude ammonium sulfate.

[0046] 4. The clear liquid in the clarification tank 4 is divided into three parts, one part is used to dissolve crude ammonium sulfate to make acid, one part is sent to salt extraction to produce ammonium thiocyanate and crude ammonium sulfate, and the remaining part is sent to the desulfurization unit after cooling to reduce the consumption of cooling water, and also reduce the impact of the clear liquid after melting sulfur returning to the desulfurization unit on the desulfurization efficiency.

[0047] 5. The unqualified crude ammonium sulfate produced by salt extraction is added to the dissolving kettle 5 to prepare a concentrated solution, which is sprayed into the incinerator 6 for combustion, thereby increasing the output of concentrated sulfuric acid. At the same time, because the solid content of the concentrated solution can be guaranteed to reach more than 80% at above 80°C, the water content sprayed into the incinerator 6 is minimized, and the amount of dilute acid produced by the acid-making device is reduced. The amount of dilute acid is only 15% of the concentrated acid output at most, which effectively guarantees the digestion and treatment of the dilute sulfuric acid in the subsequent process.

[0048] 6. The unqualified crude ammonium sulfate produced by salt extraction is added to the dissolving kettle 5 to prepare a concentrated liquid, which is sprayed into the incinerator 6 for combustion. This can reduce the amount of crude ammonium sulfate added to the coal and then enter the coke oven for thermal decomposition again, thereby reducing the heat consumption of coking, reducing the hydrogen sulfide and ammonia contained in the coal gas, and reducing the load of the coal gas purification section.

[0049] 7. Installing the crude ammonium sulfate hopper 14 and the quantitative feeding device 13 directly above the dissolving kettle 5 is conducive to the unloading of crude ammonium sulfate and the normal operation of the quantitative feeding device 13, ensuring that the concentration of the desulfurization concentrate is stable and meets the standard, and ensuring the stable and reliable operation of the incinerator 6 and other equipment.

[0050] 8. The utility model can ensure that the ammonium thiocyanate in the desulfurization waste liquid is recovered and extracted into high-quality ammonium thiocyanate products for sale. The crude ammonium sulfate, a byproduct that is difficult to handle obtained during the salt extraction process, is added to the clear liquid after melting sulfur and dissolved into a concentrated liquid, which not only recovers resources but also saves energy.

[0051] The above is an exemplary description of the utility model in conjunction with the accompanying drawings. Obviously, the specific implementation of the utility model is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the utility model; or the above concept and technical solution of the utility model are directly applied to other occasions without improvement, they are all within the protection scope of the utility model.

Claims

1. A device for preparing concentrated sulfuric acid from desulfurized concentrated liquid, characterized in that: It includes a multiphase separator for receiving sulfur foam concentrate, a purification tower and an oxidation tower connected to the multiphase separator, a clarification tank connected to the oxidation tower, a dissolving kettle connected to the clarification tank, an incinerator connected to the purification tower, and an acid-making system connected to the incinerator, wherein the dissolving kettle is connected to the incinerator.

2. The device for preparing concentrated sulfuric acid from desulfurized concentrated liquid according to claim 1, characterized in that: The acid-making system comprises a waste heat boiler connected to the incinerator, a purification and drying device connected to the waste heat boiler, a conversion tower connected to the purification and drying device, and an absorption tower connected to the conversion tower.

3. The device for preparing concentrated sulfuric acid from desulfurized concentrated liquid according to claim 1, characterized in that: The clarification tank is connected to a clear liquid cooler, and the clear liquid cooler is connected to a desulfurization unit.

4. The device for preparing concentrated sulfuric acid from desulfurized concentrated liquid according to any one of claims 1 to 3, characterized in that: A stirrer is arranged on the dissolving kettle.

5. The device for preparing concentrated sulfuric acid from desulfurized concentrated liquid according to any one of claims 1 to 3, characterized in that: The dissolving kettle is connected to a quantitative feeding device, the quantitative feeding device is connected to a crude ammonium sulfate hopper, and the crude ammonium sulfate hopper is filled with crude ammonium sulfate crystals.

6. The device for preparing concentrated sulfuric acid from desulfurized concentrated liquid according to any one of claims 1 to 3, characterized in that: The clarification tank is connected to the salt extraction unit.

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