A nitration reaction process of 1,2-diazooxynaphthalene-4-sulfonic acid

Abstract

The invention discloses a 1,2-diazooxynaphthalene-4-sulfonic acid nitration reaction process, which belongs to the field of chemical technology. It includes the following steps: first, sulfuric acid, an organic solvent and 1,2-diazooxynaphthalene-4-sulfonic acid (or recycled) are added to the slurry kettle to obtain an oxygenate slurry; then, when the oxygenate slurry is added to the nitrification pot A to a volume of H1, nitric acid is added dropwise, and after the volume is H2, the slurry in the nitrification pot A is continuously discharged into the empty pot nitrification pot B, and similarly discharged into the empty pot nitrification pot C, and then discharged into the nitrification pot D, and the slurry in the nitrification pot D is continuously discharged into the empty pot nitrification pot E1 (or E2), and the nitrification material reacted to the end point is subjected to static separation, the organic solvent is recycled and applied, and the remaining is diluted into the F pot, and then separated by a filter press to obtain the product. It can reduce the safety production level, reduce the work intensity of operators, improve production efficiency, greatly reduce the generation of waste acid water, and at the same time improve the yield.

Description

Technical Field

[0001] The invention relates to the technical field of chemical industry, and more specifically to a nitration reaction process of 1,2-diazooxynaphthalene-4-sulfonic acid. Background Art

[0002] Nitration reaction is an important unit reaction in organic synthetic chemistry and chemical production. Mixed acid nitration method (nitric acid and sulfuric acid are mixed in a certain proportion) is a traditional nitration method. Its outstanding advantages are simple reaction equipment and stable process. Therefore, it has always been the main method for industrial production of nitro compounds. The main method is intermittent reaction. Each batch operation process requires five processes: feeding, heating, cooling, discharging and cleaning. The production cycle is long, the risk is high, the cleaning time is long, the labor intensity is high, the amount of sulfuric acid used is large, and a large amount of waste acid water is generated. In addition, the production efficiency is low, resulting in high production costs.

[0003] Taking the production of the widely used dye intermediate 6-nitro-1,2-diazooxynaphthalene-4-sulfonic acid (referred to as 6-nitro-1,2,4-acidoxyform, or 6-nitro) as an example, the current process is to generate 6-nitro-1,2-diazooxynaphthalene-4-sulfonic acid by nitration reaction of 1,2-diazooxynaphthalene-4-sulfonic acid (referred to as 1,2,4-acidoxyform) in sulfuric acid with mixed acid. The amount of sulfuric acid used is about 3 times that of the substrate, and the nitration product is crystallized by diluting sulfuric acid. The product usually contains 6-nitro-1,2,4-acidoxyform and by-product 8-nitro-1,2-diazooxynaphthalene-4-sulfonic acid at the same time, and the product is usually accompanied by some deep nitration products, such as polynitro compounds, etc. The products produced by the traditional method usually need to be deeply refined to reach the content requirement of 90% of 6-nitro-1,2-diazooxynaphthalene-4-sulfonic acid in the national standard. Recrystallization requires the discharge of acidic wastewater 10-15 times the total weight of the solution, which not only increases costs but also harms the environment.

[0004] Although the traditional stirred tank reaction process is relatively mature, it has problems such as difficulty in recycling waste acid, many side reactions and low yield. Many developed countries no longer produce 6-nitro-1,2-diazooxynaphthalene-4-sulfonic acid and import it from my country, making the production of this product more economical. The industrial production process of 6-nitro-1,2-diazooxynaphthalene-4-sulfonic acid of some dye manufacturers still follows the process conditions of the last century. The overall low yield and large amount of wastewater have become bottlenecks restricting the sustainable development of enterprises.

[0005] On the other hand, the production process of 6-nitro-1,2-diazooxynaphthalene-4-sulfonic acid is mostly done manually, which not only reduces the production efficiency but also makes the product quality (such as product consistency evaluation, such as quality indicators and availability) difficult to control.

[0006] Increasingly stringent environmental protection and safety supervision requirements, workers' expectations for improved working environment and process product quality stability all hope to achieve continuous nitration of products, while achieving clean and safe production of products, reduction of waste acid and its resource utilization. Therefore, it is necessary to develop a solvent-based continuous nitration reaction process for 1,2-diazooxynaphthalene-4-sulfonic acid. Summary of the invention

[0007] 1. Technical problems to be solved

[0008] In view of the problems existing in the prior art, the present invention adopts DCS automatic control technology, aiming to provide a 1,2-diazooxynaphthalene-4-sulfonic acid nitration reaction process.

[0009] 2. Technical solution

[0010] To solve the above problems, the present invention adopts the following technical solutions.

[0011] A 1,2-diazooxynaphthalene-4-sulfonic acid nitration reaction process, the reaction process comprising the following steps:

[0012] S1, DCS controls to first add a certain amount of sulfuric acid, ethylene dichloride (or recycled ethylene dichloride) and a certain amount of 1,2-diazooxynaphthalene-4-sulfonic acid into the slurry kettle J1 (or J2) while stirring, and controls the temperature within 25°C to obtain oxygen slurry;

[0013] S2, DCS controls to first add H1 volume of oxygen slurry in J1 (or J2) slurry kettle to nitrification pot A, and then continuously add nitric acid and oxygen slurry in J1 (or J2) slurry kettle according to a certain feed ratio until the slurry liquid volume of nitrification pot A is H2, and at the same time, continuously discharge the slurry in nitrification pot A into the empty nitrification pot B;

[0014] S3, DCS controls the slurry in the empty nitration pot B to reach the slurry volume H1, and then starts to continuously add nitric acid to the nitration pot B until the slurry volume of the nitration pot B reaches H2, and at the same time, continuously discharges the slurry in the nitration pot B into the empty nitration pot C;

[0015] S4, DCS control, after the volume of the slurry in the empty nitration pot C reaches H1, nitric acid is continuously added to the nitration pot C until the volume of the slurry liquid in the nitration pot C reaches H2, and the slurry in the nitration pot C is continuously discharged into the empty nitration pot D until the volume reaches H1, and then 97% nitric acid is continuously added to the nitration pot D until the volume of the slurry in the nitration pot D reaches H2, and the slurry in the nitration pot D is continuously discharged into the empty nitration pot E1;

[0016] S5, DCS control, after the volume of the slurry in the empty nitration pot E1 reaches H1, start to continuously add nitric acid to the nitration pot E1 according to a certain ratio until the volume of the slurry in the nitration pot E1 reaches H2, then stop adding nitric acid, and continuously discharge the slurry in the nitration pot D into the empty nitration pot E2, and at the same time continuously add nitric acid to the nitration pot E1 until the volume of the slurry in the nitration pot E1 reaches H3, then stop adding nitric acid, after the reactants in the nitration pot E1 react to the end point, put the slurry in the nitration pot E1 into the dilution pot F and add ice water for dilution, after the dilution is completed, use a filter press to separate it to obtain 6-nitro-1,2-diazooxynaphthalene-4-sulfonic acid.

[0017] Furthermore, the weight ratio of sulfuric acid, ethylene dichloride and 1,2-diazooxynaphthalene-4-sulfonic acid in step S1 is 0.3-1:3-6:1.

[0018] Furthermore, when the slurry in the nitrification pot A is continuously discharged into the empty nitrification pot B, the weight ratio of nitric acid and oxygen slurry continuously added to the nitrification pot A is 1:0.26-0.275.

[0019] Furthermore, the stirring speed of the beating kettle is 55-90 rpm.

[0020] Furthermore, the volume ratio of H1, H2 and H3 is 1:2-4:2.5-3.0.

[0021] Furthermore, the concentration of the sulfuric acid used is 98-100%.

[0022] Furthermore, the stirring speed of nitrifying pot A, nitrifying pot B, nitrifying pot C, nitrifying pot D, nitrifying pot E1 and nitrifying pot E2 is 45-70 rpm.

[0023] Furthermore, the nitric acid concentration is 97-98% and the temperature is 5-10°C.

[0024] Furthermore, the content of 1,2-diazooxynaphthalene-4-sulfonic acid in step S1 is 75-90%.

[0025] Furthermore, in step S1, the beating temperature of 1,2-diazooxynaphthalene-4-sulfonic acid is 10-20°C.

[0026] 3. Beneficial effects

[0027] Compared with the prior art, the advantages of the present invention are:

[0028] The present invention provides a continuous nitration reaction process of 1,2-diazooxynaphthalene-4-sulfonic acid, which can reduce the safety level, reduce the work intensity of operators, improve production efficiency, reduce production costs, reduce the generation of waste water, and improve yield and product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the process flow of the present invention. DETAILED DESCRIPTION

[0030] Embodiment 1: A nitration reaction process of 1,2-diazooxynaphthalene-4-sulfonic acid, the reaction process comprising the following steps:

[0031] Nitration pot A, nitration pot B, nitration pot C, nitration pot D and nitration pots E1 and E2 are the same nitration pots.

[0032] S1, DCS control first adjust the stirring speed to 65 rpm in the J1 slurry kettle, add 1250 kg of ethylene dichloride and 300 kg of 98% sulfuric acid, then add 625 kg of 80% 1,2-diazooxynaphthalene-4-sulfonic acid, adjust the stirring speed to 85 rpm, stir for 2 hours, control the temperature at 13-17°C, beat evenly, then add 1250 kg of ethylene dichloride, adjust the stirring speed to 65 rpm, stir for 30 minutes and control the temperature of the slurry kettle within 15°C to obtain oxygen slurry;

[0033] S2, DCS control first add the oxygen slurry in J1 slurry kettle to nitrification pot A until the liquid level h1 = 0.3 meters, then start to uniformly add 97% nitric acid at a rate of 6.5 kg / hour, control the nitration temperature at 22-24 ° C, the oxygen slurry in J1 slurry kettle dripping speed 171.25 kg / hour, then add the oxygen slurry in the slurry kettle to nitrification pot A until the liquid level h2 = 0.9 meters, and then continuously discharge the slurry in nitrification pot A to the empty nitrification pot B at 177.75 kg / hour;

[0034] S3, DCS control, when the slurry in the empty nitration pot B reaches the liquid level h1=0.3m, start to continuously add 97% nitric acid to the nitration pot B at a rate of 6.5KG / hour, control the nitration temperature at 24-26℃, when the slurry liquid level in the nitration pot B is h2=0.9m, continuously discharge the material to the empty nitration pot C at a rate of 184.25KG / hour;

[0035] S4, DCS controls the slurry level in the empty nitration pot C to h1=0.3m, then starts to continuously add 97% nitric acid to the nitration pot C at a rate of 6.5KG / hour, controls the nitration temperature at 24-26°C, when the slurry level in the nitration pot C reaches h2=0.9m, then continuously discharges the slurry in the nitration pot C to the empty nitration pot D at 190.75KG / hour, controls the nitration temperature at 24-26°C, when the slurry level in the nitration pot D reaches h1=0.3m, then starts to continuously add 97% nitric acid to the nitration pot D at a rate of 6.5KG / hour; when the slurry level in the nitration pot D reaches h2=0.9m, then continuously discharges the slurry in the nitration pot D to the empty nitration pot E1 at 197.25KG / hour;

[0036] S5, DCS control, when the slurry in the empty nitration pot E1 reaches the liquid level h1=0.3m, start to continuously add 97% nitric acid to the nitration pot E1 at a rate of 6.5KG / hour; control the nitration temperature at 24-26℃, when the slurry liquid level in the nitration pot E1 reaches h2=0.9m, stop adding the slurry in the nitration pot D to E1, and continuously discharge the slurry in the nitration pot D to the empty nitration pot E2 at 197.25KG / hour, but start to continuously add 97% nitric acid to the nitration pot E1 at a rate of 6.5KG / hour until the liquid level h2=0.9m 3=0.903 meters, stop adding nitric acid, control the nitration temperature at 24-26℃, wait until the reactants in the nitration pot E1 react to the end point, put the slurry in the nitration pot E1 into the dilution pot F and add 300KG of ice water for dilution. After the dilution is completed, let it stand for 1 hour to separate the lower layer of 6-nitro-1,2-diazooxynaphthalene-4-sulfonic acid, use a centrifuge to separate, and obtain 6-nitro-1,2-diazooxynaphthalene-4-sulfonic acid and mother liquor. The filter cake is washed with a small amount of water. Washed with ice water, the filter cake is 128.5KG, the content is 90%, the 115.65KG is 96.5% pure, the by-product 8-nitro-1,2-diazooxynaphthalene-4-sulfonic acid is 2.9% pure, the yield is 98%, the production capacity is 28.9KG / hour; the mother liquor and washing water are 422.9KG in total, the sulfuric acid content is 13.49%, the mother liquor consumption is: 3.66 tons / ton of finished product, the mother liquor COD is 2200, and the upper organic layer is recovered and reused.

[0037] Embodiment 2: A 1,2-diazooxynaphthalene-4-sulfonic acid nitration reaction process, the reaction process comprising the following steps:

[0038] Nitrification pot A, nitrification pot B, nitrification pot C, nitrification pot D and nitrification pot E1, E2 are the same nitrification pots. S1, DCS control first adjust the stirring speed to 60 rpm in the J1 slurry kettle, add 1300KG of dichloroethane (or recycled), 400KG of 98.2% sulfuric acid, and then add 625KG 80% 1,2-diazooxynaphthalene-4-sulfonic acid, adjust the stirring speed to 90 rpm, stir for 2 hours, control the temperature at 12-15°C, and after beating evenly, add 1700KG of dichloroethane (or recycled), adjust the stirring speed to 60 rpm, stir for 30 minutes and control the slurry kettle temperature within 15°C to obtain oxygen slurry;

[0039] S2, DCS control first add the oxygen slurry in J1 slurry kettle to nitrification pot A until the liquid level h1 = 0.3 meters, then start to uniformly add 97.1% nitric acid at a rate of 6.7 kg / hour, control the nitration temperature at 24-26 ° C, the oxygen slurry in J1 slurry kettle dripping speed 201.25 kg / hour, then drop the oxygen slurry in the slurry kettle into nitrification pot A until the liquid level h2 = 0.9 meters, and then continuously discharge the slurry in nitrification pot A into the empty pot nitrification pot B at 207.95 kg / hour;

[0040] S3, DCS control, when the slurry in the empty nitration pot B reaches the liquid level h1 = 0.3 meters, start to continuously add 97.1% nitric acid to the nitration pot B at a rate of 6.7 kg / hour, control the nitration temperature at 25-27 ° C, when the slurry liquid level in the nitration pot B is h2 = 0.9 meters, continuously discharge the material to the empty nitration pot C at a rate of 214.65 kg / hour;

[0041] S4, DCS controls the slurry level in the empty nitration pot C to h1 = 0.3 meters, and then starts to continuously add 97.1% nitric acid to the nitration pot C at a rate of 6.7 kg / hour, and controls the nitration temperature to 25-27 ° C. When the slurry level in the nitration pot C is h2 = 0.9 meters, the slurry in the nitration pot C is continuously discharged into the empty nitration pot D at 221.35 kg / hour, and the nitration temperature is controlled to 25-27 ° C. When the slurry level in the nitration pot D is h1 = 0.3 meters, 97.1% nitric acid is continuously added to the nitration pot D at a rate of 6.7 kg / hour; when the slurry level in the nitration pot D is h2 = 0.9 meters, the slurry in the nitration pot D is continuously discharged into the empty nitration pot E2 at 228.05 kg / hour;

[0042] S5, DCS control, when the slurry in the empty nitration pot E2 reaches the liquid level h1=0.3m, start to continuously add 97.1% nitric acid to the nitration pot E2 at a rate of 6.7KG / hour; control the nitration temperature at 25-27℃, when the slurry liquid level in the nitration pot E2 reaches h2=0.9m, stop adding the slurry in the nitration pot D to E2, and continuously discharge the slurry in the nitration pot D to the empty nitration pot E1 at 228.05KG / hour, but start to continuously add 97.1% nitric acid to the nitration pot E2 at a rate of 6.7KG / hour until the liquid level h2=0.9m 3=0.901 meters, stop adding nitric acid, control the nitration temperature at 25-27℃, wait until the reactants in the nitration pot E2 react to the end point, put the slurry in the nitration pot E2 into the dilution pot F and add 380KG of ice water for dilution. After the dilution is completed, let it stand for 1 hour to separate the lower layer of 6-nitro-1,2-diazooxynaphthalene-4-sulfonic acid, separate it by centrifuge, and obtain 6-nitro-1,2-diazooxynaphthalene-4-sulfonic acid and mother liquor. Wash the filter cake with a small amount of ice water , filter cake 129.9KG, content of 89.5%, 116.23KG purity of 96.8%, by-product 8-nitro-1,2-diazooxynaphthalene-4-sulfonic acid purity of 2.5%, yield of 98.5%, production capacity of 29.1KG / hour; mother liquor and washing water total 522KG, sulfuric acid content 14.67%, mother liquor unit consumption: 4.49 tons / ton of finished product, mother liquor COD is 2100, upper organic layer 3006KG recovery and application.

[0043] Comparative Example 1:

[0044] A 1,2-diazooxynaphthalene-4-sulfonic acid nitration reaction process, the reaction process comprising the following steps:

[0045] Add 1200kg of 98.5% sulfuric acid to the reactor, control the temperature to <45℃ while stirring at 60r / min, add 353kg of 85% 1,2-diazooxynaphthalene-4-sulfonic acid, beat for about 2-3 hours, cool to 15-20℃ evenly, slowly drip 234kg of mixed acid at 15-25℃ for 4-5 hours, the mass ratio of sulfuric acid to nitric acid in the mixed acid is 2:1, react at 20-25℃ for 5 hours after the addition is complete, take samples and detect the endpoint, then dilute into 4000kg of 12℃ water, control the dilution temperature to <35℃, The product was allowed to stand at 25-35°C for 16-24 hours, and filtered to obtain 384 kg of product cake, 318.6 kg of 100% and 5468 kg of mother liquor. The purity of 6-nitro-1,2-diazooxynaphthalene-4-sulfonic acid in the product was 93.2%, the purity of by-product 8-nitro-1,2-diazooxynaphthalene-4-sulfonic acid was 5.5%, the total yield was 90%, the production capacity was 8.4-10.6 kg / ton, the mother liquor consumption was 17 tons / ton of product, the sulfuric acid content in the mother liquor was 24.3%, the COD was 12600, and the production cycle was 32-40 hours.

Claims

1. A 1,2-diazooxynaphthalene-4-sulfonic acid nitration reaction process, characterized in that: The reaction process comprises the following steps: S1, DCS control, first add a certain amount of sulfuric acid, ethylene dichloride and a certain amount of 1,2-diazooxynaphthalene-4-sulfonic acid into the slurry kettle while stirring, and control the temperature within 25°C to obtain oxygen slurry; S2, DCS controls to first add oxygen slurry of volume H1 into nitrification pot A, then drop nitric acid until the slurry volume of nitrification pot A reaches H2, and then continuously discharge the slurry in nitrification pot A into the empty nitrification pot B; S3, DCS controls the slurry in the empty nitration pot B to reach the slurry volume H1, starts to continuously add nitric acid to the nitration pot B until the volume reaches H2, and then continuously discharges the slurry in the nitration pot B into the empty nitration pot C; S4, DCS control, when the volume of the slurry in the empty nitration pot C reaches H1, nitric acid is continuously added to the nitration pot C until the volume is H2, and then the slurry in the nitration pot C is continuously discharged into the empty nitration pot D. When the volume of the slurry in the nitration pot D reaches H1, nitric acid is continuously added to the nitration pot D until the volume is H2, and then the slurry in the nitration pot D is continuously discharged into the empty nitration pot E1; S5, DCS control, after the volume of the slurry in the empty nitration pot E1 reaches H1, nitric acid is continuously added to the nitration pot E1 until the volume of the slurry in the nitration pot E1 reaches H2, then stop adding nitric acid and slurry; stop putting the slurry in the nitration pot D into E1, switch the slurry in the nitration pot D to the empty nitration pot E2, and continuously add nitric acid to the nitration pot E1 until the volume of the slurry in the nitration pot E1 reaches H3, then stop adding nitric acid, after the reactants in the nitration pot E1 react to the end point, let stand for stratification, put the slurry in the nitration pot E1 into the dilution pot F with ice water for dilution, after the dilution is completed, separate it by using a filter press to obtain 6-nitro-1,2-diazooxynaphthalene-4-sulfonic acid; The volume ratio of H1, H2 and H3 is 1:2-4:2.5-3.1; The weight ratio of sulfuric acid, ethylene dichloride and 1,2-diazooxynaphthalene-4-sulfonic acid in step S1 is 0.3-1:2-6:

1.

2. A 1,2-diazooxynaphthalene-4-sulfonic acid nitration reaction process according to claim 1, characterized in that: When the slurry in the nitrification pot A is continuously discharged into the empty nitrification pot B, the feeding ratio of nitric acid and oxygen slurry continuously added to the nitrification pot A is 1:0.26-0.

275.

3. A 1,2-diazooxynaphthalene-4-sulfonic acid nitration reaction process according to claim 1, characterized in that: The stirring speed of the slurry kettle is 55-90 rpm.

4. A 1,2-diazooxynaphthalene-4-sulfonic acid nitration reaction process according to claim 1, characterized in that: The concentration of sulfuric acid used is 98-100%.

5. A 1,2-diazooxynaphthalene-4-sulfonic acid nitration reaction process according to claim 1, characterized in that: The stirring speed of nitrifying pot A, nitrifying pot B, nitrifying pot C, nitrifying pot D, nitrifying pot E1 and E2 is 45-70 rpm.

6. A 1,2-diazooxynaphthalene-4-sulfonic acid nitration reaction process according to claim 1, characterized in that: The nitric acid concentration is 97-98%.

7. A 1,2-diazooxynaphthalene-4-sulfonic acid nitration reaction process according to claim 1, characterized in that: The content of 1,2-diazooxynaphthalene-4-sulfonic acid in step S1 is 75-90%.

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