Removal device for residual acid and catalyst in isooctyl thioglycolate

Abstract

The utility model discloses a device for removing residual acid and a catalyst in isooctyl thioglycolate, and belongs to the technical field of purification and treatment of isooctyl thioglycolate. Comprising a mixing assembly, a reaction assembly, a settling tower and an acidification kettle which are sequentially connected, the mixing assembly is provided with an isooctyl thioglycolate feed port and a dilute alkali feed port, a feed port of the reaction assembly is communicated with a middle liquid inlet of the settling tower, and the upper portion and the lower portion of the settling tower are each provided with a filler layer. The top of the settling tower is provided with a settling tower upper liquid outlet, the bottom of the settling tower is provided with a settling tower lower liquid outlet, the settling tower lower liquid outlet is communicated with the liquid inlet of the acidification kettle, and the settling tower is provided with a hydrochloric acid liquid inlet. The waste of raw materials is reduced, and meanwhile, the problem that the waste liquid treatment cost and difficulty are increased due to the fact that the organic matter content in the waste liquid is too high is avoided; a continuous treatment mode is adopted, automation is achieved, the treatment efficiency is high, and tedious manual operation is avoided.

Description

TECHNICAL FIELD

[0001] The device for removing residual acid and catalyst in mercaptoacetic acid isopropyl ester belongs to the technical field of purification and treatment of mercaptoacetic acid isopropyl ester. BACKGROUND

[0002] The synthesis of mercaptoacetic acid isopropyl ester is generally carried out by extracting mercaptoacetic acid in an aqueous solution with isopropyl alcohol, and the organic phase after extraction is a mixture of isopropyl alcohol and mercaptoacetic acid. Then, under the action of a catalyst (generally concentrated sulfuric acid or p-toluene sulfonic acid), an esterification reaction is completed. The mercaptoacetic acid isopropyl ester after the esterification reaction contains a small amount of unreacted mercaptoacetic acid and catalyst. Therefore, the removal of the mercaptoacetic acid and catalyst is required before entering the rectification process.

[0003] The traditional treatment method is to transfer the mercaptoacetic acid isopropyl ester to a water removal kettle, add water into the kettle, stir and then separate the layers, manually observe the state of the material in the discharge pipeline through a sight glass, and then separate the washing water and the mercaptoacetic acid isopropyl ester. This method usually requires 2-3 times the amount of water of the mercaptoacetic acid isopropyl ester, thus a large amount of washing water is generated. The content of mercaptoacetic acid in the washing water is low (usually below 0.3wt%), which is difficult to recover and is generally directly transported to a sewage workshop for waste water treatment. This not only causes waste of raw materials, but also increases the amount of sewage and the difficulty of treatment. In addition, this treatment method is intermittent and requires frequent manual on-site operation, thus the treatment efficiency is low. CONTENT OF THE UTILITY MODEL

[0004] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art, provide a device for removing residual acid and catalyst in mercaptoacetic acid isopropyl ester, which can realize continuous treatment and reduce the cost and difficulty of waste liquid treatment.

[0005] The utility model adopts the technical scheme that the device for removing residual acid and catalyst in mercaptoacetic acid isopropyl ester comprises a mixing assembly, a reaction assembly, a settling tower and an acidification kettle which are connected in sequence, the mixing assembly is provided with a mercaptoacetic acid isopropyl ester feed inlet and a dilute alkali feed inlet, the feed inlet of the reaction assembly is communicated with the middle liquid inlet of the settling tower, the upper part and the lower part of the settling tower are both provided with a filler layer, the top of the settling tower is provided with a settling tower upper liquid outlet, the bottom of the settling tower is provided with a settling tower lower liquid outlet, the settling tower lower liquid outlet is communicated with the liquid inlet of the acidification kettle, and the settling tower is provided with a hydrochloric acid liquid inlet.

[0006] Further, the upper part of the settling tower is provided with a settling tower upper liquid level meter, the settling tower upper liquid level meter is located on the upper side of the filler layer, the lower part of the settling tower is provided with a settling tower lower liquid level meter, and the settling tower lower liquid level meter is located on the lower side of the filler layer.

[0007] Further, the upper liquid level meter and the lower liquid level meter of the settling tower are both magnetic flap liquid level meters.

[0008] Further, the mixing assembly comprises a pair of sprayers and a pair of sprayer nozzles, and the two ends of each sprayer are provided with a sprayer nozzle.

[0009] Further, the reaction assembly is a tubular reactor.

[0010] Further, a tubular reactor pH meter is arranged at the outlet of the reaction assembly, and an acidification kettle pH meter is arranged at the outlet of the acidification kettle.

[0011] Further, the application further comprises a receiving tank in communication with the outlet of the acidification kettle.

[0012] Compared with the prior art, the application has the beneficial effects that:

[0013] The application adopts a dilute alkaline solution to treat the catalyst and mercaptoacetic acid in mercaptoacetic acid iso-octyl ester, and the amount of wastewater generated is reduced by more than 80% compared with the original process, the content of sodium mercaptoacetate in the washing liquid is higher, and after acidification, the washing liquid can be returned to the production system to continue to synthesize mercaptoacetic acid iso-octyl ester as raw material, thereby reducing raw material waste, and also reducing the content of organic matter in the waste liquid, reducing the cost and difficulty of waste liquid treatment; the continuous treatment mode is adopted to realize automation, and the treatment efficiency is high, and manual tedious operation is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a structural schematic view of a device for removing residual acid and catalyst in mercaptoacetic acid iso-octyl ester.

[0015] In the figure: 1, sprayer; 2, tubular reactor; 3, settling tower; 4, acidification kettle; 5, receiving tank; 101, sprayer nozzle; 102, upper liquid level meter of the settling tower; 103, lower liquid level meter of the settling tower; 104, filler layer; 105, upper liquid outlet of the settling tower; 106, hydrochloric acid inlet; 107, mercaptoacetic acid iso-octyl ester inlet; 108, dilute alkali inlet; 109, acidification kettle pH meter; 110, tubular reactor pH meter. DETAILED DESCRIPTION

[0016] Figure 1 is the best embodiment of the application, and the following will be combined with the accompanying drawings to further describe the application. Figure 1 The application will be further described.

[0017] The utility model discloses a kind of removal device of residual acid and catalyst in mercaptoacetic acid isooctyl ester, including the mixing assembly, reaction assembly, settling tower 3 and acidification kettle 4 connected in sequence, mixing assembly is provided with mercaptoacetic acid isooctyl ester feed port 107 and dilute alkali feed port 108, the feed port of reaction assembly is communicated with the middle part liquid inlet of settling tower 3, the upper portion and lower portion of settling tower 3 are provided with packing layer 104, the top of settling tower 3 is provided with settling tower upper portion liquid outlet 105, the bottom of settling tower 3 is provided with settling tower lower portion liquid outlet, and settling tower lower portion liquid outlet is communicated with the liquid inlet of acidification kettle 4, and settling tower 3 is provided with hydrochloric acid liquid inlet 106.The utility model uses dilute aqueous solution to treat catalyst and mercaptoacetic acid in mercaptoacetic acid isooctyl ester, and the generation amount of final waste water is reduced by more than 80% than original process, and the content of sodium mercaptoacetate in washing liquid is higher, which can be returned to production system after acidification, as raw material to continue to synthesize mercaptoacetic acid isooctyl ester, reduce raw material waste, also avoid that organic content in waste liquid is too high, increase waste liquid treatment cost and difficulty;Using the mode of continuous processing, automation is realized, processing efficiency is high, and tedious manual operation is avoided.

[0018] The utility model will be further described below in conjunction with specific embodiments, however, people skilled in the art should understand that the detailed description given herein in conjunction with the drawings is for better explanation, and the structure of the utility model must exceed these limited embodiments, and for some equivalent alternative or common means, detailed description is not given in the text, but still belongs to the protection scope of the application.

[0019] Specifically, as shown in the figure: Figure 1 The mixing assembly includes a pair of sprayers 1 and a pair of sprayer nozzles 101. The pair of sprayers 1 are vertically arranged circular pipes, and each end of the pair of sprayers 1 is provided with a pair of sprayer nozzles 101. The input port of the upper pair of sprayer nozzles 101 is the mercaptoacetic acid isooctyl ester feed port 107, and the input port of the lower pair of sprayer nozzles 101 is the dilute alkali feed port 108. In this embodiment, the reaction assembly is a vertically arranged tubular reactor 2.

[0020] The mercaptoacetic acid isooctyl ester and the dilute alkali of a certain flow rate enter the pair of sprayers 1 through the two pair of sprayer nozzles 101 respectively, and the two materials collide and mix at a high flow rate. The two materials after preliminary mixing enter the tubular reactor 2. The two materials in the tubular reactor 2 further mix and react. The mercaptoacetic acid in the mercaptoacetic acid isooctyl ester and the acidic catalyst react with the dilute alkali to generate the corresponding sodium salt dissolved in water. A tubular reactor pH meter 110 is arranged at the discharge port of the tubular reactor 2 to detect the reaction of the mercaptoacetic acid and the catalyst with the dilute alkali in real time. The reacted material enters the settling tower 3 for oil-water settling separation.

[0021] The upper and lower parts of the settling tower 3 are provided with packing layers 104, the upper part of the settling tower 3 is provided with a settling tower upper liquid level meter 102, the settling tower upper liquid level meter 102 is located on the upper side of the packing layer 104, the lower part of the settling tower 3 is provided with a settling tower lower liquid level meter 103, the settling tower lower liquid level meter 103 is located on the lower side of the packing layer 104. In this embodiment, the settling tower upper liquid level meter 102 and the settling tower lower liquid level meter 103 are both magnetic float liquid level meters. The upper part of the settling tower 3 on the upper side of the packing layer 104 is provided with a settling tower upper liquid outlet 105, the lower part of the settling tower 3 on the lower side of the packing layer 104 is provided with a settling tower lower liquid outlet, the settling tower lower liquid outlet is communicated with the feed inlet of the acidification kettle 4, the middle part of the settling tower 3 between the two packing layers 104 is provided with a middle liquid inlet, and the acidification kettle 4 is provided with a hydrochloric acid liquid inlet 106. In this embodiment, the outlet of the acidification kettle 4 is also connected with a receiving tank 5, and the acidification kettle 4 is provided with an acidification kettle pH meter 109.

[0022] The mixture after the reaction of the mercaptoacetic acid iso-octyl ester and the dilute alkali is introduced into the settling tower 3 from the middle liquid inlet of the settling tower 3, due to the difference in density, the organic matter such as mercaptoacetic acid iso-octyl ester will float up, and the aqueous solution containing sodium mercaptoacetate and catalyst sodium salt will sink down, the floating organic phase and the sinking aqueous phase will further be subjected to oil-water separation when passing through the packing layer 104, finally the organic phase such as mercaptoacetic acid iso-octyl ester is discharged from the settling tower upper liquid outlet 105 to go to a rectification process, and the aqueous phase is transported to the acidification kettle 4 from the settling tower lower liquid outlet, the float ball in the settling tower upper liquid level meter 102 can float up in the mercaptoacetic acid iso-octyl ester, which is used to detect the liquid level of the organic phase in the upper part of the settling tower 3, the float ball in the settling tower lower liquid level meter 103 can float up in water, but cannot float up in the mercaptoacetic acid iso-octyl ester, which is used to detect the liquid level of the aqueous phase in the bottom of the settling tower 3, so as to ensure that the aqueous phase with a certain liquid level is always maintained in the bottom of the settling tower 3.

[0023] The aqueous phase in the bottom of the settling tower 3 is introduced into the acidification kettle 4 at a certain flow rate, and hydrochloric acid is simultaneously added into the acidification kettle 4 from the hydrochloric acid liquid inlet 106 at a certain flow rate, under the action of the hydrochloric acid, the sodium mercaptoacetate in the aqueous phase is converted into mercaptoacetic acid, and the generated aqueous solution of mercaptoacetic acid is introduced into the receiving tank 5 from the outlet of the acidification kettle 4 in a U-shaped overflow manner, and the acidification kettle pH meter 109 of the outlet of the acidification kettle 4 is used to detect the reaction condition of the material in the kettle in real time.

[0024] The working process of the device for removing residual acid and catalyst in the mercaptoacetic acid iso-octyl ester is as follows:

[0025] S1 the mercaptoacetic acid iso-octyl ester containing residual acid and catalyst is reacted with the dilute alkali aqueous solution after passing through the pair of sprayers 1, and the reacted material is introduced into the tubular reactor 2 for settling separation;

[0026] S2 mercaptoacetic acid isooctyl ester and other organic matters are discharged from the upper liquid outlet 105 of the settling tower, enter the next purification process, the water phase containing sodium mercaptoacetate and catalyst sodium salt is discharged from the lower liquid outlet at the bottom of the settling tower to the acidification kettle 4, hydrochloric acid is input into the acidification kettle 4 through the hydrochloric acid inlet 106, and sodium mercaptoacetate is converted into mercaptoacetic acid;

[0027] S3 the generated mercaptoacetic acid is transported to the extraction process as raw material to continue the synthesis of mercaptoacetic acid isooctyl ester.

[0028] Specifically, concentrated sulfuric acid is used as a catalyst in esterification reaction, and sodium bicarbonate is used to treat the catalyst and mercaptoacetic acid in mercaptoacetic acid isooctyl ester. The flow rate of mercaptoacetic acid isooctyl ester (mercaptoacetic acid content 0.5wt% max, concentrated sulfuric acid content 3wt‰) is 3000 kg / h, and the flow rate of 5wt% sodium bicarbonate solution is 700 kg / h. After preliminary mixing in the eductor 1, the mixture is reacted in the tubular reactor 2. The pH of the reacted mixture is 8.2, the mixture is separated and settled in the settling tower 3, the residual acid in the mercaptoacetic acid isooctyl ester is 0.02wt%, the water phase at the bottom of the settling tower 3 is added to the acidification kettle 4 at a flow rate of 700 kg / h, hydrochloric acid is added to the acidification kettle 4 at a flow rate of 50 kg / h, and the pH of the reacted material is 0.54. The content of mercaptoacetic acid is 1.92wt%, the mercaptoacetic acid solution is transported to the extraction process, and the synthesis of mercaptoacetic acid isooctyl ester is continued.

[0029] The above is only a preferred embodiment of the present application, and is not intended to limit the present application in other forms. Any skilled person in the art can modify or change the above disclosed technical content to equivalent embodiments. However, any simple modification, equivalent change and modification of the above embodiments without departing from the technical solution of the present application, according to the technical essence of the present application, still belongs to the protection scope of the technical solution of the present application.

Claims

1. A device for removing residual acid and catalyst from isooctyl mercaptoacetate, characterized in that: The mixture includes a mixing component, a reaction component, a settling tower (3), and an acidification vessel (4) connected in sequence. The mixing component is provided with a mercaptoacetic acid isooctyl ester inlet (107) and a dilute alkali inlet (108). The inlet of the reaction component is connected to the middle liquid inlet of the settling tower (3). The upper and lower parts of the settling tower (3) are provided with packing layers (104). The top of the settling tower (3) is provided with an upper liquid outlet (105). The bottom of the settling tower (3) is provided with a lower liquid outlet. The lower liquid outlet of the settling tower is connected to the liquid inlet of the acidification vessel (4). The settling tower (3) is provided with a hydrochloric acid inlet (106).

2. The apparatus for removing residual acid and catalyst from isooctyl thioglycolate according to claim 1, characterized in that: A settling tower upper level gauge (102) is provided at the upper part of the settling tower (3), and the settling tower upper level gauge (102) is located on the upper side of the packing layer (104). A settling tower lower level gauge (103) is provided at the lower part of the settling tower (3), and the settling tower lower level gauge (103) is located on the lower side of the packing layer (104).

3. The apparatus for removing residual acid and catalyst from isooctyl thioglycolate according to claim 2, characterized in that: Both the upper level gauge (102) and the lower level gauge (103) of the settling tower are magnetic float level gauges.

4. The apparatus for removing residual acid and catalyst from isooctyl thioglycolate according to claim 1, characterized in that: The mixing component includes a sprayer (1) and a sprayer nozzle (101), with sprayer nozzles (101) provided at both ends of the sprayer (1).

5. The apparatus for removing residual acid and catalyst from isooctyl thioglycolate according to claim 1, characterized in that: The reaction assembly is a tubular reactor (2).

6. The apparatus for removing residual acid and catalyst from isooctyl mercaptoacetate according to claim 1, characterized in that: A tubular reactor pH meter (110) is installed at the outlet of the reaction assembly, and an acidification reactor pH meter (109) is installed at the outlet of the acidification reactor (4).

7. The apparatus for removing residual acid and catalyst from isooctyl thioglycolate according to claim 1 or 6, characterized in that: It also includes a receiving tank (5) connected to the discharge port of the acidification vessel (4).

Images