CN109928872B - Method for high-purity synthesis of anthraquinone and co-production of magnesium sulfate - Google Patents
Method for high-purity synthesis of anthraquinone and co-production of magnesium sulfate Download PDFInfo
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Abstract
The invention discloses a method for high-purity anthraquinone synthesis and magnesium sulfate co-production, belonging to the technical field of organic chemistry. According to the process, benzene and water are sequentially adopted to carry out washing type separation twice on the o-benzoylbenzoic acid obtained by acidification and hydrolysis, the content of inorganic salt is reduced, the purity of the o-benzoylbenzoic acid entering a dehydration ring-closing reaction is improved, meanwhile, the influence of impurities on the ring-closing reaction is reduced, the o-benzoylbenzoic acid can be fully closed, the yield and the purity of anthraquinone are improved, and the generated waste acid water is subjected to filtering, suspension oil removal, adsorption and other processes to remove impurities in the waste acid water, so that high-quality magnesium sulfate with higher application value is prepared, and the ideal recycling of the waste acid water is realized.
Description
Technical Field
The invention belongs to the technical field of organic chemistry, and particularly relates to a method for synthesizing anthraquinone with high purity and co-producing magnesium sulfate.
Background
Anthraquinone is an important chemical intermediate and is widely applied to the fields of dyes, medicines, pesticides and the like. Anthraquinone is used as a raw material, and a dye intermediate with a wide application range is obtained through sulfonation, nitration and the like, is used for producing anthraquinone disperse dyes, acid dyes, reactive dyes, vat dyes and the like, and plays an important role in the field of synthetic dyes. Anthraquinone is also used in large quantities as a cooking agent for paper pulping, the production of high-concentration hydrogen peroxide and in the fertilizer industry for the manufacture of the desulfurizing agent anthraquinone disulfonic acid sodium.
The anthraquinone synthesis method mainly comprises a phthalic anhydride method, an oxidation method, a naphthoquinone method and the like. Among them, the phthalic anhydride method has the advantages of sufficient raw material sources, simple process, stable operation, no special requirements for equipment and high yield, and is widely applied to the current industrial production in China. On the one hand, however, the anthraquinone produced by the method can only be applied to the field with lower requirements on impurities, and still needs to be improved in the aspect of purity; on the other hand, a large amount of byproducts such as waste dilute sulfuric acid, aluminum chloride mother liquor and the like are generated in the production process of synthesizing anthraquinone, wherein the aluminum chloride mother liquor can be used as an excellent raw material of a polyaluminum chloride water purifying agent due to clear and transparent appearance, low organic matter content and high aluminum chloride content, so that the problem of the destination of the part of wastewater is well solved.
The waste dilute sulfuric acid is from the ring-closing reaction in the production of synthetic anthraquinone, and a large amount of acidic waste water is generated in the acid precipitation process after the reaction is finished. At present, the main methods for disposing the wastewater are: (1) directly discharged into a trench or a river, which brings about a serious pollution problem; (2) the liquid alkali is used for neutralizing to recover salt, and because the quality of the salt is not high and the price is low, an enterprise cannot bear the neutralization cost; (3) and concentrating and recycling the dilute sulfuric acid, and reusing the dilute sulfuric acid for anthraquinone production. Although simple, the method can generate a large amount of acid mist in the concentration process due to the strong corrosiveness of the sulfuric acid, thereby greatly increasing the difficulty and the cost of waste acid treatment. So that the waste acid water of anthraquinone production enterprises still basically stays on the first disposal mode.
Disclosure of Invention
The invention aims to solve the technical problem of providing a method and equipment for synthesizing anthraquinone and co-producing magnesium sulfate with high purity, which can improve the quality of anthraquinone and magnesium sulfate and improve the application value of the anthraquinone and magnesium sulfate.
In order to solve the technical problems, the technical scheme of the invention is as follows: a method for synthesizing anthraquinone with high purity and co-producing magnesium sulfate is designed, and is characterized in that: the method comprises the following steps:
(1) acylation reaction: mixing 400-450 parts by mass of phthalic anhydride, 250-300 parts by mass of benzene and 800-850 parts by mass of aluminum trichloride, reacting at 50-70 ℃ for 0.5-2 hours to obtain a mixture, and adding the mixture into 4200-4800 parts by mass of a sulfuric acid solution with the mass percentage concentration of 5-7% for acidification and hydrolysis;
(2) separation: adding benzene at 40-60 ℃ into the mixture obtained by acidification and hydrolysis in the step (1), wherein the volume ratio of the benzene to the mixture is 2-3: 1, continuously stirring, standing for 10-20 minutes, separating out a first mixed solution of benzene and o-benzoylbenzoic acid on the upper layer, injecting water into the first mixed solution, wherein the volume ratio of the water to the first mixed solution is 0.8-1.2: 1, stirring again, standing for 8-12 minutes, separating out a second mixed solution of benzene and o-benzoylbenzoic acid on the upper layer, heating the second mixed solution to 95-105 ℃, and distilling out the benzene to obtain o-benzoylbenzoic acid;
(3) closed loop: adding 850-900 parts by mass of concentrated sulfuric acid or fuming sulfuric acid into the o-benzoylbenzoic acid prepared in the step (2), heating to 130-135 ℃, and preserving heat for 0.5-1.5 hours to carry out dehydration closed loop;
(4) and (3) filtering: isolating the reactant obtained in the step (3) to obtain an anthraquinone crude product and first waste liquid, washing and filtering the anthraquinone crude product to obtain an anthraquinone wet product and second waste liquid, and drying the anthraquinone wet product to obtain a dry product anthraquinone;
(5) and (3) neutralization reaction: pouring the first waste liquid and the second waste liquid into a reaction tank, slowly adding a material containing magnesium oxide or magnesium hydroxide into the reaction tank to obtain a reaction liquid, continuously stirring the reaction liquid until the reaction liquid is neutral, stopping adding the material, and continuously stirring for a neutralization reaction;
(6) and (3) filtering: pumping the clear liquid into a plate-and-frame filter press for filtering to obtain filter mud and filtrate, pumping the filtrate into an air flotation machine, and removing oil substances on the liquid surface to obtain a first clear liquid;
(7) adsorption: pumping the first clear liquid prepared in the step (6) into an adsorption tower, and adsorbing to obtain a second clear liquid;
(8) and (3) crystallization: cooling and crystallizing the second clear liquid prepared in the step (7) to obtain magnesium sulfate crystal slurry, and drying the magnesium sulfate crystal slurry after centrifugal separation to obtain a magnesium sulfate heptahydrate finished product;
or (7) carrying out thermal state evaporation crystallization on the second clear liquid prepared in the step to obtain magnesium sulfate crystal slurry, and drying the magnesium sulfate crystal slurry after centrifugal separation to obtain the anhydrous magnesium sulfate finished product.
Preferably, the temperature of the acidic hydrolysis in step (1) does not exceed 75 ℃.
Preferably, the temperature of the neutralization reaction in the step (5) is 80-100 ℃, and the reaction time is 4-6 hours.
Preferably, the solid material produced in step (6) is returned to the reaction tank.
Preferably, the sludge produced in step (6) is returned to the reaction tank.
Preferably, the benzene distilled off in step (2) is reused in the production of anthraquinones.
Compared with the prior art, the invention has the beneficial effects that:
1. the process promotes the raw materials to participate in the acylation reaction as much as possible by specific raw material proportion and specific process conditions, and improves the yield of the o-benzoylbenzoic acid.
2. The o-benzoylbenzoic acid obtained by acidification hydrolysis is subjected to washing separation twice by adopting benzene and water, the content of inorganic salt is reduced, the purity of the o-benzoylbenzoic acid entering a dehydration closed-loop reaction is improved, the influence of impurities on the closed-loop reaction is reduced, the o-benzoylbenzoic acid can be fully closed-loop, the yield and the purity of anthraquinone are improved, and the generated waste acid water is subjected to filtering, suspension degreasing, adsorption and other processes to remove impurities in the waste acid water, so that high-quality magnesium sulfate with higher application value is prepared, and the ideal recycling of the waste acid water is realized.
3. The closed-loop reactant is subjected to segregation, washing and drying to prepare the anthraquinone, so that the purity of the anthraquinone can be further improved, and the application value of the anthraquinone is improved.
4. The temperature of acidification hydrolysis is controlled below 75 ℃, so that the generation of acid mist can be reduced, the utilization rate of sulfuric acid is improved, the sulfuric acid can participate in the acidification hydrolysis reaction more fully, and the product yield is improved.
5. The method has the advantages of simple process and easily controlled flow, can improve the yield and the quality of the anthraquinone, and utilizes the generated waste acid water to prepare the high-quality magnesium sulfate, so that the production of the anthraquinone is oriented to a benign development way of environmental protection, and the method is convenient to popularize and apply in the industry.
Detailed Description
The present invention will be described in further detail with reference to specific embodiments.
Example one
The specific steps of synthesizing anthraquinone and co-producing magnesium sulfate in this example are as follows:
(1) acylation reaction: mixing 400 parts by mass of phthalic anhydride, 300 parts by mass of benzene and 800 parts by mass of aluminum trichloride, reacting at 50 ℃ for 2 hours to obtain a mixture, adding the mixture into 4200 parts by mass of sulfuric acid solution with the mass percentage concentration of 7% for acidification and hydrolysis, wherein the temperature of acidification and hydrolysis is not more than 75 ℃;
(2) separation: adding 60 ℃ benzene into the mixture obtained by acidification and hydrolysis in the step (1), wherein the volume ratio of the benzene to the mixture is 2:1, continuously stirring, standing for 20 minutes, separating out a first mixed solution of the benzene and the o-benzoylbenzoic acid on the upper layer, adding water into the first mixed solution, wherein the volume ratio of the water to the first mixed solution is 0.8:1, stirring again, standing for 12 minutes, separating out a second mixed solution of the benzene and the o-benzoylbenzoic acid on the upper layer, and heating the second mixed solution to 105 ℃ to distill off the benzene to obtain the o-benzoylbenzoic acid;
(3) closed loop: adding 850 parts by mass of concentrated sulfuric acid into the o-benzoylbenzoic acid prepared in the step (2), heating to 135 ℃, and preserving heat for 0.5 hour to perform dehydration ring closure;
(4) and (3) filtering: isolating the reactant obtained in the step (3) to obtain an anthraquinone crude product and first waste liquid, washing and filtering the anthraquinone crude product to obtain an anthraquinone wet product and second waste liquid, and drying the anthraquinone wet product to obtain a dry product anthraquinone;
(5) and (3) neutralization reaction: and pouring the first waste liquid and the second waste liquid into a reaction tank, slowly adding a material containing magnesium oxide or magnesium hydroxide into the reaction tank to obtain a reaction liquid, continuously stirring the reaction liquid until the reaction liquid is neutral, stopping adding the material, continuously stirring to perform a neutralization reaction, wherein the temperature of the neutralization reaction is 80 ℃, and the reaction time is 6 hours.
(6) And (3) filtering: settling the cured slurry obtained in the step (5) to obtain solid materials and clear liquid, returning the solid materials to the reaction tank for continuous reaction, pumping the clear liquid into a plate-and-frame filter press for filtering to obtain filter mud and filtrate, returning the filter mud to the reaction tank for continuous reaction, pumping the filtrate into an air flotation machine, and removing oil substances on the liquid surface to obtain first clear liquid;
(7) adsorption: pumping the first clear liquid prepared in the step (6) into an adsorption tower, and adsorbing to obtain a second clear liquid;
(8) and (3) crystallization: cooling and crystallizing the second clear liquid prepared in the step (7) to obtain magnesium sulfate crystal slurry, and drying the magnesium sulfate crystal slurry after centrifugal separation to obtain a magnesium sulfate heptahydrate finished product;
or (7) carrying out thermal state evaporation crystallization on the second clear liquid prepared in the step to obtain magnesium sulfate crystal slurry, and drying the magnesium sulfate crystal slurry after centrifugal separation to obtain the anhydrous magnesium sulfate finished product.
The benzene distilled in the step (2) can be returned to the step (1) or the beginning of the step (2) and is applied to the production of the anthraquinone again.
The yield of the anthraquinone produced by the embodiment is 98.5%, the purity of the anthraquinone is 99.4%, the purity of the prepared magnesium sulfate is 99.1%, the magnesium sulfate can be applied to industries with strict requirements such as fertilizers and medicines, the application value is improved, and anthraquinone production enterprises are willing to be put into actual production, so that the anthraquinone production is in the way of environmental protection of sustainable development.
Example two
The difference between the present embodiment and the first embodiment is:
in the step (1), 450 parts by mass of phthalic anhydride, 250 parts by mass of benzene and 850 parts by mass of aluminum trichloride are mixed, the mixture is obtained after reaction for 0.5 hour at 70 ℃, and the mixture is added into 4800 parts by mass of sulfuric acid solution with the mass percentage concentration of 5% for acidification and hydrolysis;
in the step (2), adding 40 ℃ benzene into the mixture, wherein the volume ratio of the benzene to the mixture is 3:1, continuously stirring, standing for 10 minutes, separating out a first mixed solution of the benzene and the o-benzoyl benzoic acid on the upper layer, injecting water into the first mixed solution, wherein the volume ratio of the water to the first mixed solution is 1.2:1, standing for 8 minutes after stirring again, separating out a second mixed solution of the benzene and the o-benzoyl benzoic acid on the upper layer, and then heating the second mixed solution to 95 ℃ to distill out the benzene to obtain the o-benzoyl benzoic acid;
in the step (3), 900 parts by mass of concentrated sulfuric acid is added into the o-benzoylbenzoic acid prepared in the step (2), the temperature is raised to 130 ℃, and the temperature is kept for 1.5 hours to carry out dehydration ring closure;
in the step (5), the temperature of the neutralization reaction is 100 ℃ and the reaction time is 6 hours.
The yield of anthraquinone produced in this example was 98.8%, the purity was 98.9%, and the purity of the magnesium sulfate produced was 99.3%.
EXAMPLE III
The difference between the present embodiment and the first embodiment is:
in the step (1), 425 parts by mass of phthalic anhydride, 275 parts by mass of benzene and 825 parts by mass of aluminum trichloride are mixed, the mixture is obtained after reaction for 1.5 hours at 60 ℃, and the mixture is added into 4500 parts by mass of sulfuric acid solution with the mass percentage concentration of 6% for acidification and hydrolysis;
in the step (2), adding 50 ℃ benzene into the mixture, wherein the volume ratio of the benzene to the mixture is 2.5:1, continuously stirring, standing for 15 minutes, separating out a first mixed solution of the benzene and the o-benzoylbenzoic acid on the upper layer, injecting water into the first mixed solution, wherein the volume ratio of the water to the first mixed solution is 1:1, standing for 10 minutes after stirring again, separating out a second mixed solution of the benzene and the o-benzoylbenzoic acid on the upper layer, and then heating the second mixed solution to 100 ℃ to distill out the benzene to obtain the o-benzoylbenzoic acid;
in the step (3), 875 parts by mass of fuming sulfuric acid is added into the o-benzoylbenzoic acid prepared in the step (2), the temperature is raised to 133 ℃, and the temperature is kept for 1 hour to carry out dehydration ring closing;
in the step (5), the temperature of the neutralization reaction is 90 ℃ and the reaction time is 5 hours.
The yield of anthraquinone produced in this example was 97.5%, the purity was 98.3%, and the purity of the magnesium sulfate produced was 98.5%.
The foregoing is directed to preferred embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.
Claims (4)
1. A method for synthesizing anthraquinone and co-producing magnesium sulfate is characterized in that: the preparation method comprises the following steps:
(1) acylation reaction: mixing 400-450 parts by mass of phthalic anhydride, 250-300 parts by mass of benzene and 800-850 parts by mass of aluminum trichloride, reacting at 50-70 ℃ for 0.5-2 hours to obtain a mixture, adding 4200-4800 parts by mass of a sulfuric acid solution with a mass percentage concentration of 5-7% into the mixture, and carrying out acidification hydrolysis at a temperature not exceeding 75 ℃;
(2) separation: adding benzene at 40-60 ℃ into the mixture obtained by acidification and hydrolysis in the step (1), wherein the volume ratio of the benzene to the mixture is 2-3: 1, continuously stirring, standing for 10-20 minutes, separating out a first mixed solution of benzene and o-benzoylbenzoic acid on the upper layer, injecting water into the first mixed solution, wherein the volume ratio of the water to the first mixed solution is 0.8-1.2: 1, stirring again, standing for 8-12 minutes, separating out a second mixed solution of benzene and o-benzoylbenzoic acid on the upper layer, heating the second mixed solution to 95-105 ℃, and distilling out the benzene to obtain o-benzoylbenzoic acid;
(3) closed loop: adding 850-900 parts by mass of concentrated sulfuric acid or fuming sulfuric acid into the o-benzoylbenzoic acid prepared in the step (2), heating to 130-135 ℃, and preserving heat for 0.5-1.5 hours to carry out dehydration ring closure;
(4) and (3) filtering: isolating the reactant obtained in the step (3) to obtain an anthraquinone crude product and first waste liquid, washing and filtering the anthraquinone crude product to obtain an anthraquinone wet product and second waste liquid, and drying the anthraquinone wet product to obtain a dry product anthraquinone;
(5) and (3) neutralization reaction: pouring the first waste liquid and the second waste liquid into a reaction tank, slowly adding a material containing magnesium oxide or magnesium hydroxide into the reaction tank to obtain a reaction liquid, continuously stirring the reaction liquid until the reaction liquid is neutral, stopping adding the material, continuously stirring to perform a neutralization reaction, wherein the temperature of the neutralization reaction is 80-100 ℃, and the reaction time is 4-6 hours;
(6) and (3) filtering: settling the cured slurry obtained in the step (5) to obtain a solid material and a clear liquid, pumping the clear liquid into a plate-and-frame filter press for filtering to obtain filter mud and filtrate, pumping the filtrate into an air flotation machine, and removing oil substances on the liquid surface to obtain a first clear liquid;
(7) adsorption: pumping the first clear liquid prepared in the step (6) into an adsorption tower, and adsorbing to obtain a second clear liquid;
(8) and (3) crystallization: cooling and crystallizing the second clear liquid prepared in the step (7) to obtain magnesium sulfate crystal slurry, and drying the magnesium sulfate crystal slurry after centrifugal separation to obtain a magnesium sulfate heptahydrate finished product;
or (7) carrying out thermal state evaporation crystallization on the second clear liquid prepared in the step to obtain magnesium sulfate crystal slurry, and drying the magnesium sulfate crystal slurry after centrifugal separation to obtain the anhydrous magnesium sulfate finished product.
2. The method for synthesizing anthraquinone and co-producing magnesium sulfate according to claim 1, wherein the method comprises the following steps: and (4) returning the solid material generated in the step (6) to the reaction tank.
3. The method for synthesizing anthraquinone and co-producing magnesium sulfate according to claim 1, wherein the method comprises the following steps: and (4) returning the filter mud generated in the step (6) to the reaction tank.
4. The method for the synthesis of anthraquinone and the co-production of magnesium sulfate according to any one of claims 1 to 3, characterized in that: the benzene distilled in the step (2) is applied to the production of anthraquinone again.
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| CN111847491A (en) * | 2020-07-31 | 2020-10-30 | 山东泓瑞医药科技股份公司 | Treatment method of amantadine production waste acid |
| CN113416124B (en) * | 2021-06-21 | 2022-06-07 | 山东裕滨新材料有限公司 | Method for preparing anthraquinone substitute auxiliary agent based on 2-alkylanthraquinone closed-loop waste liquid |
| CN114477250B (en) * | 2022-01-25 | 2024-04-19 | 重庆毂运科技有限公司 | Method for preparing magnesium sulfate by utilizing anthraquinone waste acid |
| CN116177576A (en) * | 2022-12-01 | 2023-05-30 | 百色实华环保科技有限公司 | Comprehensive utilization method of waste acid of anthraquinone production device |
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