A process for producing H acid by alkali fusion in an ammonia environment

Abstract

The present invention relates to the technical field of H acid preparation, and in particular to a process for producing H acid by alkali fusion under an ammonia environment. Amino T acid generates a chromotropic acid byproduct during alkali fusion, and the chromotropic acid is the amino group of H acid replaced by a hydroxyl group. The hydroxyl group on the naphthalene ring can generate an amino group under the catalysis of sulfite, so the chromotropic acid generates H acid under an ammonia environment. In the present invention, alkali fusion under an ammonia environment can effectively inhibit the generation of chromotropic acid by the side reaction of alkali fusion, and improve the H acid yield. Based on amino T acid, the H acid yield can be increased to about 85%, effectively reducing the cost.

Description

Technical Field

[0001] The invention relates to the technical field of H acid preparation, and in particular to a process for producing H acid by alkali fusion in an ammonia environment. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] H acid (1-amino-8-naphthol-3,6-disulfonic acid monosodium) is an important intermediate for the production of reactive dyes. At present, the production of H acid uses refined naphthalene as raw material, and amino T acid is first prepared through sulfonation, nitration, denitrification, neutralization, reduction, sodium chloride salting out and other processes, and amino T acid is then produced through alkali fusion, acidification and other processes. However, the mother liquor produced in the production of H acid belongs to the "five highs" organic wastewater with high concentration, high acidity, high salinity, high chroma and high toxicity, with a chemical oxygen demand (Chemical Oxygen Demand-COD) as high as 80,000 to 100,000, a salt content of 1 to 20%, and a chroma of 4,000 to 6,000 times. It is difficult to effectively treat these "five highs" organic wastewaters using traditional biochemical and physicochemical methods; and the use of unconventional extraction, pyrolysis, adsorption and other methods for treatment, the pretreatment cost alone is as high as thousands of yuan, and it is still impossible to achieve thorough and effective treatment. At present, no enterprise can effectively treat the "five highs" organic wastewater generated in the production of H acid and make it meet the discharge standards. Although some wastewater can be concentrated by MVR to produce mixed salts of ammonium sulfate and sodium chloride, this mixed salt contains a large amount of organic matter and is difficult to purify, so it can only be treated as solid waste.

[0004] At present, the problem of treating high-concentration salt-containing wastewater of H acid has been effectively solved through the recycling of materials. However, the total yield of H acid is still relatively low. The yield based on refined naphthalene is less than 50%, and the yield based on amino T acid is only about 70%. Therefore, it is urgent to solve the problem of low total yield of H acid. Summary of the invention

[0005] In order to overcome the above problems, the present invention provides a process for producing H acid by alkali fusion in an ammonia environment.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0007] A process for producing H acid by alkali fusion in an ammonia environment comprises the following steps:

[0008] S1, refined naphthalene is separated to obtain amino T acid after sulfonation, nitration, denitration, neutralization and reduction, and an alkaline solution and a high dispersant are added to the amino T acid, and after being adjusted to a defined concentration, a substance that can produce free ammonia and methanol are added to carry out alkali fusion; the substance that can produce free ammonia is selected from one or more of ammoniacal liquor, urea and ammonium salt;

[0009] S2. After the alkali fusion is completed, the free ammonia in the reaction system is absorbed by water for deammoniation. The deammonated alkali fusion material is diluted, neutralized, acidified, desulfurized, cooled, and filtered to obtain a filter cake. The filter cake is washed with water, filtered, and dried to obtain H acid.

[0010] In one or more embodiments, in step S1, the solute alkali in the alkaline solution is selected from sodium hydroxide or potassium hydroxide.

[0011] In one or more embodiments, in step S1, the mass ratio of the solute base to the amino T acid in the alkaline solution is (80-110):100.

[0012] In one or more embodiments, in step S1, the high dispersant is selected from a quaternary ammonium salt, and the quaternary ammonium salt is selected from one or more of tetrabutylammonium bromide, dodecyldimethylbenzylammonium chloride 1227, and hexadecyltrimethylammonium chloride 1631.

[0013] In one or more embodiments, in step S1, the amount of high dispersant added is 0.1-2% of the total mass of amino acid and alkali solution. The purpose of adding high dispersant is to fully mix the organic matter and alkali, so that alkali melting can proceed more smoothly.

[0014] In one or more embodiments, in step S1, the ammonium salt includes ammonium chloride, ammonium sulfate, ammonium bicarbonate, ammonium nitrate, ammonium carbonate and ammonium acetate.

[0015] In one or more embodiments, in step S1, the ammonia water is ammonia water or liquid ammonia with a concentration greater than 1%.

[0016] In one or more embodiments, in step S1, the mass of the substance that can generate free ammonia is 1% to 15% of the total mass of the amino acid and the alkaline solution.

[0017] In one or more embodiments, in step S1, when the substance capable of generating free ammonia is selected from ammonium salt, the mass fraction of the ammonium salt is 5-40%.

[0018] In one or more embodiments, in step S1, the alkali melting temperature is 165-185° C., and the alkali melting time is 1-5 h.

[0019] In one or more embodiments, in step S1, an alkaline solution and a high dispersant are added to the amino T acid, and the concentration is adjusted to a mass fraction of the amino T acid of 20-30%.

[0020] In one or more embodiments, in step S2, after deamination, the pH of the alkali solution is adjusted to 4 to 5. The pH is adjusted to ensure efficient neutralization reaction.

[0021] In one or more embodiments, in step S2, dilute sulfuric acid is used to acidify to pH=2.

[0022] In one or more embodiments, in step S2, alkali is used to absorb the sulfur dioxide removed during desulfurization. The alkali that absorbs the sulfur dioxide can be used to produce sulfite, thereby preventing pollution caused by sulfur dioxide and producing byproducts with utilization value.

[0023] The beneficial effects of the present invention are:

[0024] (1) The present invention relates to the technical field of H acid preparation, and specifically to a process for producing H acid by alkali fusion in an ammonia environment. Amino T acid will generate chromotropic acid as a byproduct during alkali fusion. Chromotropic acid is the amino group of H acid replaced by hydroxyl group. The hydroxyl group on the naphthalene ring can generate amino group under the catalysis of sulfite. Therefore, chromotropic acid will generate H acid in an ammonia environment. In the present invention, alkali fusion in an ammonia environment can effectively inhibit the generation of chromotropic acid as a side reaction of alkali fusion, and improve the yield of H acid. Based on amino T acid, the yield of H acid can be increased to about 85%, effectively reducing the cost.

[0025] (2) The present invention recovers the substance that can generate free ammonia by deammonification after alkali melting, thereby realizing the recycling of the substance that can generate free ammonia and reducing costs.

[0026] (3) The sulfur element introduced by the present invention is absorbed by the alkali during the desulfurization process to prepare sulfite with economic value, thereby preventing nitrogen and sulfur elements from being discharged in the form of ammonia, sulfur oxides, etc. and becoming pollutants. DETAILED DESCRIPTION

[0027] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0028] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0029] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

[0030] It should be noted that the sulfonation, nitration, denitration, neutralization and reduction process of refined naphthalene are referred to the prior art unless otherwise specified. The parts in the embodiments are all parts by weight and the percentages are all percentages by weight.

[0031] The H acid in the present invention is 1-amino-8-naphthol-3,6-disulfonic acid monosodium, and the amino T acid is 1-amino-3,6,8-naphthalenetrisulfonic acid.

[0032] The weight parts of amino T acid solutions in the following examples are all percentages, i.e. the weight of pure amino T acid.

[0033] Example 1

[0034] A process for producing H acid by alkali fusion in an ammonia environment comprises the following steps:

[0035] (1) After sulfonation, nitration, denitration, neutralization and reduction, amino T acid is separated from refined naphthalene. Take 120 parts (weight parts, percentage) of amino T acid solution, add 200 parts of 50% (mass fraction) sodium hydroxide solution and 12274 parts of dodecyl dimethyl benzyl ammonium chloride, concentrate to the amino T acid mass fraction of 26%, add 20 parts of 20% (mass fraction) ammonium sulfate solution and 60 parts of methanol, and alkali melt at 175 ℃ for 3 hours.

[0036] (2) After recovering methanol and ammonium sulfate, an alkaline molten liquid is obtained, which is diluted with water and acidified to pH=2 using 30% (mass fraction) dilute sulfuric acid. The desulfurized liquid is desulfurized and the sulfur dioxide removed is absorbed using sodium hydroxide to produce sodium sulfite. The desulfurized alkaline molten neutralized liquid is cooled and filtered to obtain a filter cake. The filter cake is washed with water, filtered and dried to obtain 107.6 parts of H acid with a content of 85.45%. The H acid yield based on amino T acid is 86.06% and the chromatographic purity is 98.63%.

[0037] Example 2

[0038] A process for producing H acid by alkali fusion in an ammonia environment comprises the following steps:

[0039] (1) After sulfonation, nitration, denitration, neutralization and reduction, refined naphthalene is separated to obtain amino T acid. Take 180 parts (weight parts, percentage) of amino T acid solution, add 350 parts of 50% (mass fraction) sodium hydroxide solution and 16316 parts of cetyltrimethylammonium chloride, concentrate to the amino T acid mass fraction of 28%, add 30 parts of 40% (mass fraction) urea solution and 75 parts of methanol, and alkali melt at 170-180℃ for 2.5 hours.

[0040] (2) After methanol is recovered, an alkaline molten liquid is obtained, which is diluted with water and acidified to pH=2 using 30% (mass fraction) dilute sulfuric acid. The desulfurized liquid is desulfurized and the sulfur oxide removed is absorbed using sodium hydroxide to produce sodium sulfite. The desulfurized alkaline molten neutralized liquid is cooled and filtered to obtain a filter cake. The filter cake is washed with water, filtered by pressure, and dried to obtain 160.3 parts of H acid with a content of 85.67%. The H acid yield based on amino T acid is 85.69% and the chromatographic purity is 98.32%.

[0041] Example 3

[0042] A process for producing H acid by alkali fusion in an ammonia environment comprises the following steps:

[0043] (1) After sulfonation, nitration, denitration, neutralization and reduction, amino T acid is separated from refined naphthalene. Take 120 parts (weight parts, percentage) of amino T acid solution, add 260 parts of 50% (mass fraction) sodium hydroxide solution and 16314 parts of cetyltrimethylammonium chloride, concentrate to the amino T acid mass fraction of 23.5%, add 35 parts of 15% (mass fraction) ammonia water and 50 parts of methanol, and alkali melt at 170 ℃ for 5 hours.

[0044] (2) After recovering methanol and ammonia water, an alkaline molten liquid was obtained, which was diluted with water and acidified to pH=2 using 30% (mass fraction) dilute sulfuric acid. The desulfurized liquid was desulfurized and the sulfur oxide removed was absorbed using sodium hydroxide to produce sodium sulfite. The desulfurized alkaline molten neutralized liquid was cooled and filtered to obtain a filter cake. The filter cake was washed with water, filtered and dried to obtain 105.4 parts of H acid with a content of 85.32%. The H acid yield based on amino T acid was 84.17% and the chromatographic purity was 98.24%.

[0045] Example 4

[0046] A process for producing H acid by alkali fusion in an ammonia environment comprises the following steps:

[0047] (1) After sulfonation, nitration, denitration, neutralization and reduction, refined naphthalene is separated to obtain amino T acid. Take 150 parts (weight parts, percentage) of amino T acid solution, add 280 parts of 50% (mass fraction) sodium hydroxide solution and 12275 parts of dodecyl dimethyl benzyl ammonium chloride, concentrate to the amino T acid mass fraction of 25.5%, add 45 parts of 10% (mass fraction) ammonia water and 65 parts of methanol, and react at 180°C for 2 hours.

[0048] (2) After recovering methanol and ammonia water, an alkaline molten liquid is obtained, which is diluted with water and acidified to pH=2 using 30% (mass fraction) dilute sulfuric acid. The desulfurized liquid is desulfurized and the sulfur oxide removed is absorbed using sodium hydroxide to produce sodium sulfite. The desulfurized alkaline molten neutralized liquid is cooled and filtered to obtain a filter cake. The filter cake is washed with water, filtered by pressure, and dried to obtain 105.9 parts of H acid with a content of 85.65%. The H acid yield based on amino T acid is 85.23% and the chromatographic purity is 98.36%.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A process for producing monosodium 1-amino-8-naphthol-3,6-disulfonate by alkali fusion in an ammonia environment, characterized in that: The steps include: S1, separating refined naphthalene through sulfonation, nitration, denitration, neutralization and reduction to obtain 1-amino-3,6,8-naphthalenetrisulfonic acid, adding an alkaline solution and a high dispersant to the 1-amino-3,6,8-naphthalenetrisulfonic acid, adjusting the concentration to a defined value, adding a substance that can generate free ammonia and methanol, and performing alkali melting; the substance that can generate free ammonia is selected from one or more of ammonia water, urea and ammonium salt; S2. After the alkali fusion is completed, the free ammonia in the reaction system is absorbed by water for deammoniation. The deaminated alkali fusion material is diluted, neutralized, acidified, desulfurized, cooled, and filtered to obtain a filter cake. The filter cake is washed with water, filtered, and dried to obtain 1-amino-8-naphthol-3,6-disulfonic acid monosodium; Wherein, in step S1, the solute alkali in the alkaline solution is selected from sodium hydroxide or potassium hydroxide; the mass ratio of the solute alkali in the alkaline solution to 1-amino-3,6,8-naphthalenetrisulfonic acid is (80-110):100; The mass of the substance that can generate free ammonia is 1% to 15% of the total mass of 1-amino-3,6,8-naphthalenetrisulfonic acid and the alkaline solution; The alkali melting temperature is 165~185 ℃, and the alkali melting time is 1~5 h.

2. The process according to claim 1, characterized in that In step S1, the high dispersant is selected from quaternary ammonium salt, and the quaternary ammonium salt is selected from one or more of tetrabutylammonium bromide, dodecyldimethylbenzylammonium chloride 1227, and hexadecyltrimethylammonium chloride 1631.

3. The process according to claim 1, characterized in that In step S1, the amount of the high dispersant added is 0.1-2% of the total mass of 1-amino-3,6,8-naphthalenetrisulfonic acid and the alkaline solution.

4. The process according to claim 1, characterized in that In step S1, the ammonium salt is selected from ammonium chloride, ammonium sulfate, ammonium bicarbonate, ammonium nitrate, ammonium carbonate and ammonium acetate.

5. The process according to claim 1, characterized in that In step S1, an alkaline solution and a high dispersant are added to 1-amino-3,6,8-naphthalenetrisulfonic acid, and the mixture is concentrated and adjusted to a mass fraction of 1-amino-3,6,8-naphthalenetrisulfonic acid of 20-30%; In step S2, the pH of the alkali solution is adjusted to 4-5 after deamination; In step S2, alkali is used to absorb the desulfurized sulfur dioxide during desulfurization.