A method and device for decoloring and purifying by-product hydrochloric acid in a photo initiator production process

Abstract

The application discloses a kind of decolorization purification method and device of byproduct hydrochloric acid in photoinitiator production process, belong to byproduct hydrochloric acid refining utilization technical field.A kind of decolorization purification method of byproduct hydrochloric acid in photoinitiator production process, comprising the following steps: S1.in hydrochloric acid refining tower subsection packing packing and resin;S2.after packing is completed, byproduct hydrochloric acid is imported from top and is refined;S3.when resin is saturated, using hot water and nitrogen analysis regeneration, after hot water is imported, nitrogen is bubbled to the weak acidity of hot water at resin layer, and then repeat steps S1-S3;Purification hydrochloric acid using the method, change the conventional resin decolorization impurity removal, steam regeneration process, save steam, increase the life of resin, simultaneously with the characteristics of short cycle, low cost, high efficiency, in addition, the refined hydrochloric acid can be recycled, meet the clean industrial production requirements, while it is conducive to the matching and extension of enterprise's industrial chain, improve the risk resistance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of by-product hydrochloric acid refining and utilization, and more particularly relates to a decolorization and purification method and device for by-product hydrochloric acid in a photoinitiator production process. BACKGROUND

[0002] The photoinitiator is also called photosensitizer or photocuring agent, is a kind of compound which can absorb energy of a certain wavelength in the ultraviolet or visible light region, produce free radicals and cations, and thus initiate monomer polymerization, crosslinking and curing, and is widely used in the fields of chemistry, materials, medicine and the like; By-product hydrogen chloride is produced in the photoinitiator production process, when the process system cannot be reused, the most conventional utilization method for the by-product hydrogen chloride is by-product hydrochloric acid, therefore the production of hydrochloric acid in China has been mainly by-product; The by-product hydrochloric acid mostly contains organic matter, free chlorine and trace amounts of metal ions such as iron, copper and nickel, these metal ions and free chlorine impurities are difficult to remove, and the by-product hydrochloric acid reacts with the metal ions to form corresponding chlorides, so that the hydrochloric acid presents different colors. In addition, the hydrochloric acid may adsorb dust and particles in the air during storage and transportation, which also causes the hydrochloric acid to discolor. Therefore, the refining and purification of hydrochloric acid has very important practical significance in industrial production.

[0003] At present, the refining and purification methods of hydrochloric acid are divided into three kinds of physical method, chemical method and biological method. The physical method mainly separates the color substances and metal ions in the hydrochloric acid by filtration, centrifugation and precipitation, and the effect is not good for the trace amount of impurities in the hydrochloric acid. The chemical method is to add a deironing agent or a decolorizing agent to adsorb interference factors, and this method has good effect. The biological method mainly uses the metabolic action of microorganisms for purification, but is limited by the survival conditions of microorganisms and the long metabolic time of microorganisms. Therefore, the ion exchange method in the chemical method is more widely used. For example, the process for removing organic matter in by-product hydrochloric acid produced in the production of chlorobenzene (CN201510103599.6) disclosed in Chinese invention patent literature, the by-product hydrochloric acid is introduced into the top of the resin tower, the adsorbed by-product hydrochloric acid is discharged from the bottom of the resin tower, after the hydrochloric acid in the resin tower is discharged, hot steam is introduced into the resin tower to vaporize and separate the adsorbed substances; but the resin regeneration needs a large amount of steam, and the high-temperature steam will damage the service life of the resin and consume a large amount of energy.

[0004] In order to solve the above problems, we need a purification method and device which has good purification effect, small environmental impact, energy saving and can efficiently utilize the by-product hydrochloric acid. SUMMARY

[0005] The present application aims to provide a kind of decolorization purification device of byproduct hydrochloric acid in the production process of photoinitiator, use the device can be integrated to complete the decolorization purification of byproduct hydrochloric acid, structure is reasonable, with short cycle, low cost, high efficiency and recyclable characteristics, effectively solve the problem of byproduct hydrochloric acid utilization difficulty in the field of photoinitiator;In addition, based on the device, another application purpose of the present application is also to optimize a kind of decolorization purification method of byproduct hydrochloric acid in the production process of photoinitiator.

[0006] To achieve the above object, the present application provides the following technical scheme:

[0007] The present application provides a kind of decolorization purification method of byproduct hydrochloric acid in the production process of photoinitiator, comprising the following steps:

[0008] S1, in hydrochloric acid refining tower, subsection is filled with packing and resin;

[0009] S2, after filling, byproduct hydrochloric acid is introduced from top to be refined;

[0010] S3, when resin is saturated, use hot water and nitrogen analysis regeneration, after hot water is introduced, nitrogen is bubbled to the hot water in resin layer is weakly acidic, then repeat steps S1-S3;

[0011] The resin of above-mentioned step S1 includes ion exchange resin and macroporous adsorption resin, ion exchange resin is used to absorb the ion impurities in byproduct hydrochloric acid, macroporous adsorption resin is used to absorb the organic impurities in byproduct hydrochloric acid;The filling ratio of ion exchange resin and macroporous adsorption resin is 1:1-4:1, and ion exchange resin is excessive compared with macroporous adsorption resin.

[0012] As a further improvement of the present application, in the above-mentioned step S1, the material of hydrochloric acid refining tower is selected from graphite or steel lined with four fluorine.

[0013] As a further improvement of the present application, the packing in the above-mentioned step S1 is filled in the bottom of refining tower, and glass ball or quartz sand or water cap that does not react with hydrochloric acid is selected, which is used to control the effective residence time, block resin loss and reduce the turbidity of particulate matter in hydrochloric acid.

[0014] As a further improvement of the present application, the ion exchange resin in the above-mentioned step is anion exchange resin.

[0015] As a further improvement of the present application, the ion exchange resin and macroporous adsorption resin in the above-mentioned step are alternately added, forming a "sandwich cake" form, and the total filling height is about 20-80 cm from the liquid inlet.

[0016] As a further improvement of the present application, in the above-mentioned step S2, the liquid level of byproduct hydrochloric acid is maintained higher than the height of resin layer when the byproduct hydrochloric acid stock solution is introduced into the hydrochloric acid tower.

[0017] As a further improvement of the present application, the resin layer has a height of about 3m.

[0018] As a further improvement of the present application, the step S2 controls the refining rate of the hydrochloric acid to be 2-7BV / h, and the refining rate that is too fast or too slow will affect the effect of resin adsorption.

[0019] As a further improvement of the present application, in the step S3, the hot water temperature for resin desorption and regeneration is 30-80℃, and nitrogen bubbling is assisted, and the nitrogen pressure is 1-100kpa.

[0020] As a further improvement of the present application, the nitrogen pressure is preferably 2-10kpa.

[0021] As a further improvement of the present application, the pH value of the hot water in the resin layer is 5-6.

[0022] As a further improvement of the present application, in the step S3, the hot water in the desorption and regeneration process becomes acidic water, which is used as an absorption liquid for absorbing the by-product hydrochloric acid in the process of producing the photoinitiator, and when the iron ion content in the acidic water reaches a set value, the acidic water is directly reused in the process of wastewater treatment by the combination of iron-carbon reduction and Fenton oxidation in the wastewater treatment system.

[0023] A decolorization and purification device for by-product hydrochloric acid in the process of producing a photoinitiator is used to realize the above-mentioned purification method.

[0024] As a further improvement of the present application, the decolorization and purification device for by-product hydrochloric acid in the process of producing a photoinitiator has a filler layer at the bottom of the refining tower, and a resin layer at the upper part of the filler layer, and the resin layer is an ion exchange resin layer and a macroporous adsorption resin layer which are alternately stacked and used for decolorization and impurity removal and purification of by-product hydrochloric acid; a nitrogen pipe is fixedly installed at the top of the refining tower, and the bottom of the nitrogen pipe is below the hot water liquid level, and is used for nitrogen bubbling to improve the effect of hot water regeneration of the resin.

[0025] As a further improvement of the present application, the insertion depth of the nitrogen pipe is 45%-55% of the height of the resin layer, and the insertion depth that is too shallow will result in poor resin regeneration effect, and the insertion depth that is too deep may agitate the filler layer, resulting in the sinking and escape of the resin.

[0026] Compared with the prior art, the beneficial effects of the present application are that: by using resin to refine byproduct hydrochloric acid and using hot water and nitrogen to resolve and regenerate after the resin is saturated, the conventional resin decolorization and impurity removal process and steam regeneration process are changed, steam is saved, the service life of the resin is increased, and the process has the characteristics of short cycle, low cost and high efficiency; by alternately adding ion exchange resin and macroporous adsorption resin, the alternating layer structure provides more adsorption sites and channels, increases the contact opportunities between the byproduct hydrochloric acid and the resin, and thus improves the refining effect; by setting the proportion of ion exchange resin to be greater than the proportion of macroporous adsorption resin to remove impurities in the byproduct hydrochloric acid and improve the quality of the final obtained hydrochloric acid; by setting the nitrogen pipe to fill nitrogen for bubbling during the hot water regeneration process, the effect of resin regeneration is improved, which reduces the difficulty of resin resolution regeneration and improves the quality of hydrochloric acid; by recycling the concentrated hydrochloric acid obtained by purification to the photoinitiator preparation system or selling it, the recycling of hydrochloric acid is realized, and the acidic water obtained by the hot water in the resolution regeneration process is used as the absorption liquid for absorbing byproduct hydrochloric acid in the photoinitiator production process; when the iron ion content in the acidic water reaches a set value, the acidic water is directly recycled to the iron-carbon reduction-Fenton oxidation reaction combined wastewater treatment process in the sewage treatment system, which meets the requirements of clean industrial production, is conducive to the matching and extension of the industrial chain of the enterprise, and improves the anti-risk ability. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a purification process schematic diagram of the present application;

[0028] Figure 2 is a purification device structure schematic diagram of the present application.

[0029] Explanation of reference numerals in the drawing:

[0030] 1 filler layer, 2 resin layer, 21 ion exchange resin layer, 22 macroporous adsorption resin layer, 3 nitrogen pipe. DETAILED DESCRIPTION

[0031] The technical solutions of the present application will be further described below with reference to the accompanying drawings. Figure 1 - the accompanying drawings Figure 2 The technical solutions of the present application will be further described below with reference to the accompanying drawings.

[0032] The method for decoloring and purifying by-product hydrochloric acid in the production process of a photoinitiator comprises removing the impurities in the by-product hydrochloric acid through the mutual superposition of an ion exchange resin layer 21 and a macroporous adsorption resin layer 22, wherein the ion exchange resin has weak acidity in the solution, and the purpose of removing anions is achieved through the adsorption and exchange reaction between the functional groups in the resin and the anions in the hydrochloric acid based on the ion exchange process; the macroporous adsorption resin selectively adsorbs impurities from the solution through physical adsorption, and is not affected by the existence of inorganic salts and strong ions and low molecular compounds, so as to achieve the purpose of removing the impurities in the by-product hydrochloric acid; when the resin is saturated, hot water and nitrogen are used for desorption and regeneration, the hot water can make the resin swell through heating, and the adsorbed substances in the resin are washed out through the flow of water, nitrogen is filled in the bubble with the hot water, so as to improve the effect of hot water regeneration; after the regeneration is completed, the by-product hydrochloric acid can continue to be purified through the resin, the resin continues to be desorbed and regenerated by using hot water and nitrogen after saturation, and the operation is cycled, so as to achieve the purpose of purifying the by-product hydrochloric acid; the concentrated hydrochloric acid obtained through purification is reused in a photoinitiator preparation system or sold, the hot water becomes acidic water in the desorption and regeneration process, and the acidic water is used as an absorption liquid for absorbing the by-product hydrochloric acid in the production process of the photoinitiator; when the iron ion content in the acidic water reaches a set value, the acidic water is directly reused in the iron-carbon reduction-Fenton oxidation reaction combined wastewater treatment process of the sewage treatment system, the recycling of the hydrochloric acid is realized, the clean industrial production requirement is met, the enterprise's industrial chain is matched and extended, and the anti-risk ability is improved; the Fenton reagent can effectively oxidize and decompose refractory organic matter, and through the catalytic action of Fe 2+ and H2O2, active hydroxyl radicals with high reaction are generated, flocculation and adsorption are more easily generated, and the treatment effect is improved.

[0033] Example one: after adding granular quartz sand to form a 70cm-thick filler layer from bottom to top at the bottom of the hydrochloric acid tower, alternately adding 30cm-thick macroporous adsorption resin and 60cm-thick ion exchange resin, forming an ion exchange resin layer and a macroporous adsorption resin layer with a total height of 3m and a thickness ratio of 2:1 which are staggered distributed; after the filling is completed, 40℃ process water is introduced to cover the resin layer, then nitrogen is filled in the bubble under the assistance of 2kpa pressure, and the filler layer and the resin layer are cleaned and regenerated repeatedly for 3-5 times;

[0034] The yellow-green by-product hydrochloric acid with a concentration of 31%, iron ion content of 20 mg / L, free chlorine of 50 mg / L and organic matter content of about 300 mg / L is injected into the resin to immerse the resin for 48 hours; after acidification, the by-product hydrochloric acid is continuously introduced into the tower to ensure that the liquid level is higher than the resin layer, and the balance of the feed and discharge is adjusted to make the discharge rate 1-5 BV / h, and the continuous and stable operation is continued until the resin is deactivated, and the ultramicro light yellow purified hydrochloric acid with iron ion content of 2.1 mg / L, no free chlorine and organic matter content of 3.9 ppm is obtained; then the hot water and nitrogen are continuously used for regeneration, after regeneration, the by-product hydrochloric acid is added for acidification, and after acidification, the by-product hydrochloric acid is continuously introduced for purification, and the ultramicro light yellow purified hydrochloric acid with iron ion content of 2.2 mg / L, no free chlorine and organic matter content of 4.0 ppm is obtained; after multiple regeneration, the activity of the resin is maintained unchanged.

[0035] In the bottom of the hydrochloric acid tower, the quartz sand particles are added from bottom to top to form a 70 cm thick filler layer, then the 30 cm thick macroporous adsorption resin and the 60 cm thick ion exchange resin are alternately added to form the ion exchange resin layer and the macroporous adsorption resin layer with a total height of 3 m and a thickness ratio of 2:1; after filling, the 105 ℃ steam is introduced into the resin layer to clean and regenerate the filler layer and the resin layer by steam;

[0036] The yellow-green by-product hydrochloric acid with a concentration of 31%, iron ion content of 20 mg / L, free chlorine of 50 mg / L and organic matter content of about 300 mg / L is injected into the resin to immerse the resin for 48 hours, after acidification, the by-product hydrochloric acid is continuously introduced into the tower to ensure that the liquid level is higher than the resin layer, and the balance of the feed and discharge is adjusted to make the discharge rate 1-5 BV / h, and the continuous and stable operation is continued until the resin is deactivated, and the colorless transparent purified hydrochloric acid with iron ion content of 2.2 mg / L, no free chlorine and organic matter content of 3.9 ppm is obtained; then the steam is continuously used for regeneration, after regeneration, the by-product hydrochloric acid is added for acidification, and after acidification, the by-product hydrochloric acid is continuously introduced for purification, and the colorless transparent purified hydrochloric acid with iron ion content of 2.1 mg / L, no free chlorine and organic matter content of 3.9 ppm is obtained; after multiple regeneration, the activity of the resin is maintained unchanged.

[0037] By comparing example one with comparative example one, the hot water supplemented with nitrogen bubbling for cleaning and regeneration selected in the application is compared with the steam for cleaning and regeneration, the use of hot water can avoid the resin layer overheating in the regeneration process to reduce the service life, and the energy consumption of the regeneration hot water compared with the steam is also reduced; by comparing the time of complete failure of the resin, the use of hot water supplemented with nitrogen bubbling for cleaning and regeneration selected in the application can improve the service life of the resin.

[0038] Comparative Example 2: After adding granular quartz sand to form a 70 cm thick filler layer from bottom to top at the bottom of the hydrochloric acid tower, a macroporous adsorption resin layer was formed by adding a macroporous adsorption resin with a total height of 3 m; after filling was completed, process water at 40°C was passed through to submerge the resin layer, and then nitrogen was filled under the assistance of a pressure of 2 kPa to bubble, and the filler layer and the resin layer were cleaned and regenerated repeatedly 3-5 times;

[0039] Yellow-green by-product hydrochloric acid with a concentration of 31%, an iron ion content of 20 mg / L, free chlorine of 50 mg / L, and an organic matter content of about 300 mg / L was injected into the tower to submerge the resin, and maintained for 48 hours; after acidification was completed, the by-product hydrochloric acid was continuously passed into the tower to ensure that the liquid level was higher than the resin layer, the balance of the feed and discharge was adjusted, and the discharge rate was 1-5 BV / h, and continuous and stable operation was performed until the resin was deactivated, and ultrapure yellowish hydrochloric acid with an iron ion content of 14 mg / L, free chlorine of 35 mg / L, and an organic matter content of 3 ppm was obtained; then hot water and nitrogen were continuously used for regeneration, after regeneration was completed, the by-product hydrochloric acid was added for acidification, after acidification was completed, the by-product hydrochloric acid was continuously passed in for purification, and ultrapure yellowish hydrochloric acid with an iron ion content of 15 mg / L, free chlorine of 35 mg / L, and an organic matter content of 3.1 ppm was obtained.

[0040] Comparative Example 3: After adding granular quartz sand to form a 70 cm thick filler layer from bottom to top at the bottom of the hydrochloric acid tower, an ion exchange resin layer was formed by adding an ion exchange resin with a total height of 3 m; after filling was completed, process water at 40°C was passed through to submerge the resin layer, and then nitrogen was filled under the assistance of a pressure of 2 kPa to bubble, and the filler layer and the resin layer were cleaned and regenerated repeatedly 3-5 times;

[0041] Yellow-green by-product hydrochloric acid with a concentration of 31%, an iron ion content of 20 mg / L, free chlorine of 50 mg / L, and an organic matter content of about 300 mg / L was injected into the tower to submerge the resin, and maintained for 48 hours; after acidification was completed, the by-product hydrochloric acid was continuously passed into the tower to ensure that the liquid level was higher than the resin layer, the balance of the feed and discharge was adjusted, and the discharge rate was 1-5 BV / h, and continuous and stable operation was performed until the resin was deactivated, and ultrapure yellowish hydrochloric acid with an iron ion content of 14 mg / L, free chlorine of 35 mg / L, and an organic matter content of 3 ppm was obtained; then hot water and nitrogen were continuously used for regeneration, after regeneration was completed, the by-product hydrochloric acid was added for acidification, after acidification was completed, the by-product hydrochloric acid was continuously passed in for purification, and ultrapure yellowish hydrochloric acid with an iron ion content of 15 mg / L, free chlorine of 35 mg / L, and an organic matter content of 3.1 ppm was obtained.

[0042] By comparing Example One with the above Comparative Example Two and Comparative Example Three, the alternating addition of ion exchange resin and macroporous adsorption resin selected for the present application provides more adsorption sites and channels in the alternating layer structure, increasing the contact opportunities between byproduct hydrochloric acid and the resin. By comparison with Comparative Example Two which uses only a single macroporous adsorption resin and Comparative Example Three which uses only ion exchange resin, Comparative Example Two has weaker treatment capacity for iron ions and free chlorine, and Comparative Example Three has weaker treatment capacity for organic matter. Therefore, the selection of the present application to add ion exchange resin and macroporous adsorption resin alternately for purification of byproduct hydrochloric acid can improve the refining effect of byproduct hydrochloric acid.

[0043] Example Two: After adding granular quartz sand to form a 70 cm thick filler layer from the bottom up in the hydrochloric acid tower, alternately add 25 cm thick macroporous adsorption resin and 75 cm thick ion exchange resin to form ion exchange resin layers and macroporous adsorption resin layers with a total height of 3 m and a thickness ratio of 1:1 in staggered distribution; After filling is completed, 40°C process water is introduced to submerge the resin layer, then supplemented with nitrogen gas bubbling under a pressure of 2 kpa, and the filler layer and resin layer are washed and regenerated for 3-5 times;

[0044] Into the tower body, inject yellow-green byproduct hydrochloric acid with a concentration of 31%, an iron ion content of 20 mg / L, free chlorine of 50 mg / L, and an organic matter content of about 300 mg / L to submerge the resin, maintain for 48 hours, after acidification is completed, continue to introduce byproduct hydrochloric acid into the tower to ensure that the liquid level is higher than the resin layer, and adjust the feed and discharge balance to make the discharge rate 1-5 BV / h, continuously and stably run until the resin is deactivated, obtain colorless transparent purified hydrochloric acid with an iron ion content of 2.2 mg / L, no free chlorine, and an organic matter content of 3.8 ppm; then continue to regenerate with hot water and nitrogen, after regeneration is completed, add byproduct hydrochloric acid for acidification, after acidification is completed, continue to introduce byproduct hydrochloric acid for purification, obtain colorless transparent purified hydrochloric acid with an iron ion content of 2.2 mg / L, no free chlorine, and an organic matter content of 3.9 ppm; after multiple regeneration, the resin activity remains unchanged.

[0045] Example Three: After adding granular quartz sand to form a 70 cm thick filler layer from the bottom up in the hydrochloric acid tower, alternately add 20 cm thick macroporous adsorption resin and 80 cm thick ion exchange resin to form ion exchange resin layers and macroporous adsorption resin layers with a total height of 3 m and a thickness ratio of 4:1 in staggered distribution; After filling is completed, 40°C process water is introduced to submerge the resin layer, then supplemented with nitrogen gas bubbling under a pressure of 2 kpa, and the filler layer and resin layer are washed and regenerated for 3-5 times;

[0046] The yellow-green by-product hydrochloric acid with a concentration of 31%, iron ion content of 20 mg / L, free chlorine of 50 mg / L, and organic matter content of about 300 mg / L is injected into the resin to immerse the resin for 48 hours. After acidification, the by-product hydrochloric acid is continuously injected into the tower to ensure that the liquid level is higher than the resin layer. The balance of the inlet and outlet is adjusted, and the outlet rate is 1-5 BV / h. The continuous and stable operation is continued until the resin is deactivated. The purified hydrochloric acid with a trace of yellow color, iron ion content of 2.0 mg / L, no free chlorine, and organic matter content of 4.0 ppm is obtained. Then, the hot water and nitrogen are continuously used for regeneration. After regeneration, the by-product hydrochloric acid is added for acidification. After acidification, the by-product hydrochloric acid is continuously injected for purification. The purified hydrochloric acid with a trace of yellow color, iron ion content of 2.1 mg / L, no free chlorine, and organic matter content of 4.0 ppm is obtained. After multiple regeneration, the resin activity remains unchanged. The resin that is lost due to crushing is supplemented for about 1 year.

[0047] In example four, the granular quartz sand is added from bottom to top at the bottom of the hydrochloric acid tower to form a 70 cm thick filler layer. Then, the 30 cm thick macroporous adsorption resin and the 60 cm thick ion exchange resin are alternately added to form the ion exchange resin layer and the macroporous adsorption resin layer with a total height of 3 m and a thickness ratio of 2:1. After filling, the 60°C process water is injected to immerse the resin layer. Then, the nitrogen is filled under the pressure of 2 kpa for bubbling. The filling layer and the resin layer are cleaned and regenerated for 3-5 times.

[0048] The yellow-green by-product hydrochloric acid with a concentration of 31%, iron ion content of 20 mg / L, free chlorine of 50 mg / L, and organic matter content of about 300 mg / L is injected into the resin to immerse the resin for 48 hours. After acidification, the by-product hydrochloric acid is continuously injected into the tower to ensure that the liquid level is higher than the resin layer. The balance of the inlet and outlet is adjusted, and the outlet rate is 1-5 BV / h. The continuous and stable operation is continued until the resin is deactivated. The purified hydrochloric acid with a trace of yellow color, iron ion content of 2.0 mg / L, no free chlorine, and organic matter content of 4.0 ppm is obtained. Then, the hot water and nitrogen are continuously used for regeneration. After regeneration, the by-product hydrochloric acid is added for acidification. After acidification, the by-product hydrochloric acid is continuously injected for purification. The purified hydrochloric acid with a trace of yellow color, iron ion content of 2.1 mg / L, no free chlorine, and organic matter content of 4.0 ppm is obtained. After multiple regeneration, the resin activity remains unchanged. The resin that is lost due to crushing is supplemented for about 1 year.

[0049] In example five, the granular quartz sand is added from bottom to top at the bottom of the hydrochloric acid tower to form a 70 cm thick filler layer. Then, the 30 cm thick macroporous adsorption resin and the 60 cm thick ion exchange resin are alternately added to form the ion exchange resin layer and the macroporous adsorption resin layer with a total height of 3 m and a thickness ratio of 2:1. After filling, the 80°C process water is injected to immerse the resin layer. Then, the nitrogen is filled under the pressure of 2 kpa for bubbling. The filling layer and the resin layer are cleaned and regenerated for 3-5 times.

[0050] The yellow-green by-product hydrochloric acid with a concentration of 31%, iron ion content of 20 mg / L, free chlorine of 50 mg / L, and organic matter content of about 300 mg / L is injected into the resin to immerse the resin for 48 hours. After acidification, the by-product hydrochloric acid is continuously injected into the tower to ensure that the liquid level is higher than the resin layer. The balance of the feed and discharge is adjusted, and the discharge rate is 1-5 BV / h. The continuous and stable operation is performed until the resin is deactivated. The purified hydrochloric acid with iron ion content of 2.1 mg / L, no free chlorine, and organic matter content of 3.9 ppm is obtained. Then, the hot water and nitrogen are continuously used for regeneration. After regeneration, the by-product hydrochloric acid is added for acidification. After acidification, the by-product hydrochloric acid is continuously injected for purification. The purified hydrochloric acid with iron ion content of 2.1 mg / L, no free chlorine, and organic matter content of 3.9 ppm is obtained. After multiple regeneration, the activity of the resin is maintained.

[0051] In example six, the quartz sand is added from bottom to top at the bottom of the hydrochloric acid tower to form a 70 cm thick filler layer. Then, the macroporous adsorption resin and the ion exchange resin are alternately added to form a 3 m high ion exchange resin layer and a macroporous adsorption resin layer with a thickness ratio of 2:1. After filling, the process water at 40°C is injected to immerse the resin layer. Then, the nitrogen is filled under a pressure of 5 kPa for bubbling. The filling layer and the resin layer are cleaned and regenerated for 3-5 times.

[0052] The yellow-green by-product hydrochloric acid with a concentration of 31%, iron ion content of 20 mg / L, free chlorine of 50 mg / L, and organic matter content of about 300 mg / L is injected into the resin to immerse the resin for 48 hours. After acidification, the by-product hydrochloric acid is continuously injected into the tower to ensure that the liquid level is higher than the resin layer. The balance of the feed and discharge is adjusted, and the discharge rate is 1-5 BV / h. The continuous and stable operation is performed until the resin is deactivated. The purified hydrochloric acid with iron ion content of 2.1 mg / L, no free chlorine, and organic matter content of 3.9 ppm is obtained. Then, the hot water and nitrogen are continuously used for regeneration. After regeneration, the by-product hydrochloric acid is added for acidification. After acidification, the by-product hydrochloric acid is continuously injected for purification. The purified hydrochloric acid with iron ion content of 2.1 mg / L, no free chlorine, and organic matter content of 3.9 ppm is obtained. After multiple regeneration, the activity of the resin is maintained.

[0053]

[0054]

[0055] The results of the above table show that in the purification method of hydrochloric acid by-produced in the production process of the photoinitiator, with the increase of the ratio of ion exchange resin and macroporous adsorption resin within a certain range, and the control of a certain flow rate, the quality of the purified hydrochloric acid changes little; in the resin elution and regeneration process, with the increase of the temperature of hot water within a certain range, the quality of the hydrochloric acid obtained by the next purification can be improved; at the same time, the yellow-green hydrochloric acid stock solution has the same concentration of hydrochloric acid after purification, and a slightly yellow or colorless transparent solution is obtained, and the purification effect is good; within a certain range, increasing the gas pressure of nitrogen bubbling can improve the effect of regenerated resin, that is, improve the effect of subsequent hydrochloric acid decolorization and impurity removal.

[0056] Example Seven: For the above method, a purification device for by-product hydrochloric acid in the production process of the photoinitiator is also proposed, the internal bottom layer of the refining tower of the device is a filler layer 1, the upper part of the filler layer 1 is a resin layer 2, the resin layer 2 is an ion exchange resin layer 21 and a macroporous adsorption resin layer 22 alternately stacked, which is used for adsorbing impurities and purifying by-product hydrochloric acid; a nitrogen pipe 3 is fixedly installed at the top of the refining tower, the bottom of the nitrogen pipe 3 is below the hot water liquid level, which is used for nitrogen bubbling to improve the effect of hot water regenerated resin.

[0057] The above is only a preferred embodiment of the present application and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for decolorization and purification of hydrochloric acid as a by-product in a photoinitiator production process, characterized by: The method comprises the following steps: S1. Segmentally packing fillers and resins in a hydrochloric acid refining tower; S2. After the packing is completed, the by-product hydrochloric acid is introduced from the top to refine it; S3. When the resin is saturated, hot water and nitrogen are used for desorption and regeneration, and after the hot water is introduced, nitrogen is bubbled to make the hot water at the resin layer weakly acidic, and then steps S1-S3 are repeated; The resin of step S1 above comprises ion exchange resin and macroporous adsorption resin, and the packing ratio of the ion exchange resin and the macroporous adsorption resin is 1-4:1; The ion exchange resin packed in step S1 is an anion exchange resin; The ion exchange resin and the adsorption resin are alternately added to form a "sandwich cake" form, and the total packing height is 20-80 cm from the liquid inlet; In step S3, the temperature of the hot water used for desorption and regeneration of the resin is 30-80℃, nitrogen is bubbled to assist, the nitrogen pressure is 1-100kpa, and the pH value of the hot water at the resin layer is 4.5-6.5; In step S3, the hot water can cause the resin to swell by heating, and the adsorbed substances in the resin are washed out by the flow of water, and nitrogen is filled with bubbles to improve the regeneration effect of the hot water; In step S3, the acidic water obtained by the desorption and regeneration of the hot water is used as an absorption liquid for absorbing the by-product hydrochloric acid in the production process of the photoinitiator, and when the iron ion content in the acidic water reaches a set value, it is directly reused in the process of the iron-carbon reduction-Fenton oxidation reaction combined wastewater treatment system; Fenton reagent is used to oxidize and decompose the refractory organic matter. Through the catalysis of Fe 2+ and H2O2, active hydroxyl radicals with high reactivity are generated, which are more likely to flocculate and adsorb, thereby improving the treatment effect.

2. The method for decolorization and purification of hydrochloric acid by-produced in the process of producing a photoinitiator according to claim 1, characterized in that: The fillers in step S1 are packed at the bottom of the refining tower, and glass balls or quartz sand or water caps that do not react with hydrochloric acid are selected.

3. The method for decoloring and purifying the by-product hydrochloric acid in the process of producing a photoinitiator according to claim 1, characterized in that: In step S2, the by-product hydrochloric acid stock solution is introduced into the refining tower while maintaining the liquid level higher than the height of the resin layer.

4. The method for decoloring and purifying the by-product hydrochloric acid in the process of producing a photoinitiator according to claim 1, characterized in that: In step S2, the hydrochloric acid refining rate is controlled at 2-7BV / h.

5. A device for decolorizing and purifying hydrochloric acid, a byproduct of photoinitiator production, characterized in that: A purification method according to any one of claims 1-4.

6. The decoloring and purifying device for the by-product hydrochloric acid in the process of producing a photoinitiator according to claim 5, characterized in that: The refining tower has a filler layer (1) at the bottom, a resin layer (2) above the filler layer (1), and the resin layer (2) is an alternately stacked ion exchange resin layer (21) and macroporous adsorption resin layer (22) for decolorization and impurity removal to purify the by-product hydrochloric acid; a nitrogen pipe (3) is fixedly installed at the top of the refining tower, the bottom of the nitrogen pipe (3) is below the hot water liquid level, and the nitrogen pipe (3) is used for filling nitrogen bubbles to improve the effect of hot water regeneration of the resin.

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