Separation and recovery device and recovery method for glufosinate-ammonium hydrolysis low-boiling-point substances

Abstract

The invention discloses a glufosinate-ammonium hydrolysis low-boiling-point substance separation and recovery device and method, and the recovery device comprises a first rectifying tower, a cyanogen breaking reaction kettle, a second rectifying tower and a third rectifying tower, the first rectifying tower is provided with a first feed port suitable for introducing a hydrolyzed low-boiling-point substance, a first kettle bottom solution outlet suitable for extracting a first kettle bottom solution and a first distillate discharge port suitable for distilling out a first distillate; the cyanogen breaking reaction kettle is provided with a distillate feed port suitable for introducing condensed first distillate and a liquid discharge port suitable for outputting liquid subjected to cyanogen breaking treatment; the second rectifying tower is provided with a second feeding hole, an extracting agent inlet, a second distillate discharge hole and a second kettle bottom liquid outlet; the second feeding hole is suitable for introducing liquid subjected to cyanogen breaking treatment; the extracting agent inlet is suitable for introducing an extracting agent; the second distillate discharge hole is suitable for distilling a second distillate; the device can well recover ethanol and ethyl acetate respectively, improves the recovery rate, and is convenient to use.

Description

Technical Field

[0001] This invention relates to a device and method for separating and recovering low-boiling-point substances from glufosinate hydrolysis, belonging to the field of chemical separation technology. Background Technology

[0002] Currently, glufosinate, as a broad-spectrum, non-selective herbicide, possesses both high weed control and broad-spectrum activity. It is rapidly decomposed by microorganisms in soil and is widely used for weed control in arable land, orchards, tea gardens, and glufosinate-resistant genetically modified crops. In the glufosinate strecher synthesis process, hydrochloric acid and aminonitrile are added for reaction. During the hydrolysis reaction, low-boiling-point hydrolysates are drained, which generally contain ethanol, ethyl acetate, cyanide, and hydrochloric acid. Existing technologies typically neutralize the hydrolysates with liquid alkali to create an alkaline solution, then add sodium hypochlorite to destroy the cyanide before allowing them to enter the wastewater system for treatment and discharge. This method of treating the hydrolysates does not effectively recover ethanol and ethyl acetate. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a glufosinate hydrolysis low-boiling product separation and recovery device, which can effectively recover ethanol and ethyl acetate separately, improve the recovery rate, and is easy to use.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is: a glufosinate hydrolysis low-boiling-point separation and recovery device, comprising:

[0005] The first distillation column has a first feed inlet suitable for introducing hydrolyzed low-boiling substances, a first bottom liquid outlet suitable for extracting first bottom liquid, and a first distillate outlet suitable for distilling first distillate.

[0006] A cyanide-breaking reactor, wherein the cyanide-breaking reactor has a distillate inlet suitable for introducing the first distillate after condensation and a liquid outlet suitable for discharging the liquid after cyanide-breaking treatment;

[0007] The second distillation column has a second feed inlet suitable for introducing the liquid after cyanide decomposition treatment, an extractant inlet suitable for introducing the extractant, a second distillate outlet suitable for distilling out the second distillate, and a second bottom liquid outlet suitable for collecting the second bottom liquid. The second feed inlet is connected to the liquid outlet.

[0008] The third distillation column has a third feed inlet suitable for introducing the second bottom liquid, a third distillate outlet suitable for distilling the third distillate, and a third bottom liquid outlet suitable for collecting the third bottom liquid. The third feed inlet is connected to the second bottom liquid outlet.

[0009] Furthermore, in order to effectively utilize the first bottom liquid (containing dilute hydrochloric acid), the glufosinate hydrolysis low-boiling-point separation and recovery device also includes a concentration tower, the inlet of which is connected to the outlet of the first bottom liquid.

[0010] Furthermore, the cyanide-breaking reactor has a liquid alkali inlet suitable for introducing liquid alkali.

[0011] Furthermore, the cyanide-breaking reactor has a sodium hypochlorite inlet suitable for introducing sodium hypochlorite.

[0012] Furthermore, in order to condense the first distillate, a first condenser suitable for condensing the first distillate is connected between the first distillate outlet and the distillate inlet.

[0013] Furthermore, in order to effectively recycle the extractant, the glufosinate hydrolysis low-boiling-point separation and recovery device also includes a fourth distillation column. The fourth distillation column has a fourth feed inlet suitable for introducing the third bottom liquid and a fourth distillate outlet suitable for distilling the fourth distillate. The fourth feed inlet is connected to the outlet of the third bottom liquid, and the fourth distillate outlet is connected to the extractant inlet.

[0014] Furthermore, a pump is provided between the liquid outlet and the second inlet and / or between the second bottom liquid outlet and the third inlet and / or between the third bottom liquid outlet and the fourth inlet.

[0015] Furthermore, a second condenser suitable for condensing the fourth distillate is connected between the fourth distillate outlet and the extractant inlet.

[0016] Furthermore, in order to properly store the second distillate (ethyl acetate), the glufosinate hydrolysis low-boiling product separation and recovery device also includes a first storage tank, which is connected to the outlet of the second distillate and is suitable for storing the second distillate or the condensed second distillate.

[0017] Furthermore, in order to properly store the third distillate (ethanol), the glufosinate hydrolysis low-boiling product separation and recovery device also includes a second storage tank, which is connected to the outlet of the third distillate and is suitable for storing the third distillate or the condensed third distillate.

[0018] This invention also provides a recovery method for a glufosinate hydrolysis low-boiling-point substance separation and recovery device, the method comprising the following steps:

[0019] The hydrolyzed low-boiling product is continuously fed into the first distillation column for the first distillation, producing the first distillate and the first bottom liquid.

[0020] The first distillate is condensed and sent to a cyanide-crushing reactor for cyanide-crushing treatment, producing a cyanide-crushed liquid.

[0021] The liquid after cyanide removal treatment is sent to a second distillation column containing an extractant for a second distillation to produce a second distillate and a second bottom liquid.

[0022] The second bottom liquid is fed into the third distillation column for a third distillation, producing the third distillate and the third bottom liquid.

[0023] The third bottom liquid is fed into the fourth distillation column for a fourth distillation, producing a fourth distillate and a fourth bottom liquid. The fourth distillate is returned to the second distillation column as an extractant for recycling.

[0024] The hydrolyzed low-boiling products contain ethanol, ethyl acetate, cyanide, and hydrochloric acid;

[0025] The first distillate contains ethanol, ethyl acetate, and cyanide.

[0026] The second distillate was ethyl acetate;

[0027] The third distillate is ethanol;

[0028] The fourth distillate is the extractant.

[0029] Furthermore, the first distillation column is operated at atmospheric pressure with a reflux ratio of 0.2, a top temperature of 83°C, and a bottom temperature of 105°C.

[0030] The second distillation column is operated at atmospheric pressure with a reflux ratio of 1, a top temperature of 77°C, and a bottom temperature of 98.5°C.

[0031] The third distillation column is operated at atmospheric pressure with a reflux ratio of 1, a top temperature of 57°C, and a bottom temperature of 122°C.

[0032] The fourth distillation column is operated at atmospheric pressure with a reflux ratio of 1 and a top temperature of 52°C.

[0033] After adopting the above technical solution, the hydrolyzed low-boiling product (containing 27% ethanol, 26% ethyl acetate, 480 ppm cyanide, 5% hydrochloric acid, and 42% water) is continuously fed into the first distillation column. The first distillate (including ethanol, ethyl acetate, water, and cyanide) is collected from the first distillate outlet at the top of the column, cooled, and then fed into the cyanide-breaking reactor. After condensation, the first distillate enters the cyanide-breaking reactor, where a small amount of liquid alkali is added to adjust the pH of the solution to 9-10. A small amount of sodium hypochlorite is also added to break down the cyanide. The liquid after cyanide-breaking treatment can be pumped from the liquid outlet into the second distillation column, where an extractant is added. The second distillation column is for ethyl acetate recovery. 99% ethyl acetate is collected from the second distillate outlet at the top of the column, cooled, and then stored in the first storage tank. The ethanol and extractant solution, i.e., the bottom liquid of the second reactor, can be pumped into the third distillation column. The third distillation column is for ethyl acetate recovery. In the alcohol column, 99% ethanol is collected from the third distillate outlet at the top of the column. After cooling, it enters the second storage tank to store the 99% ethanol. The extractant solution, i.e., the third bottom liquid, can be pumped into the fourth distillation column, which is the extractant distillation column. The extractant is collected from the fourth distillate outlet at the top of the column, cooled, and then returned to the second distillation column for recycling. In addition, about 15% dilute hydrochloric acid can be collected from the first bottom liquid outlet of the first distillation column by pump. After passing through the concentration column, the hydrochloric acid content reaches 30% and is then reused in the original hydrolysis reaction. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the connection of the glufosinate hydrolysis low-boiling-point separation and recovery device of the present invention; wherein,

[0035] 1. First distillation column; 11. First feed inlet; 12. First bottom liquid outlet; 13. First distillate outlet;

[0036] 2. Cyanide crushing reactor; 21. Distillate inlet; 22. Liquid outlet; 23. Liquid alkali inlet; 24. Sodium hypochlorite inlet;

[0037] 3. Second distillation column; 31. Second feed inlet; 32. Extractant inlet; 33. Second distillate outlet; 34. Second bottom liquid outlet;

[0038] 4. Third distillation column; 41. Third feed inlet; 42. Third distillate outlet; 43. Third bottom liquid outlet;

[0039] 5. Fourth distillation column; 51. Fourth feed inlet; 52. Fourth distillate outlet; 53. Fourth bottom liquid outlet;

[0040] 6. Concentration tower;

[0041] 7. Pump;

[0042] 81. First condenser; 82. Second condenser; 83. Third condenser; 84. Fourth condenser;

[0043] 91. First storage tank; 92. Second storage tank. Detailed Implementation

[0044] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0045] like Figure 1 As shown, a glufosinate hydrolysis low-boiling-point separation and recovery device includes:

[0046] First distillation column 1, the first distillation column 1 having a first feed inlet 11 suitable for introducing hydrolyzed low-boiling substances, a first bottom liquid outlet 12 suitable for extracting the first bottom liquid, and a first distillate outlet 13 suitable for distilling the first distillate.

[0047] The cyanide-breaking reactor 2 has a distillate inlet 21 suitable for introducing the first distillate after condensation and a liquid outlet 22 suitable for discharging the liquid after cyanide-breaking treatment. The first distillate enters the cyanide-breaking reactor 2 at 67°C and undergoes cyanide-breaking with liquid alkali and sodium hypochlorite. The liquid after cyanide-breaking treatment enters the second distillation column 3.

[0048] The second distillation column 3 has a second feed inlet 31 suitable for introducing the liquid after cyanide destruction treatment, an extractant inlet 32 ​​suitable for introducing the extractant, a second distillate outlet 33 suitable for distilling out the second distillate, and a second bottom liquid outlet 34 suitable for collecting the second bottom liquid. The second feed inlet 31 is connected to the liquid outlet 22.

[0049] The third distillation column 4 has a third feed inlet 41 suitable for introducing the second bottom liquid, a third distillate outlet 42 suitable for distilling the third distillate, and a third bottom liquid outlet 43 suitable for collecting the third bottom liquid. The third feed inlet 41 is connected to the second bottom liquid outlet 34.

[0050] Specifically, such as Figure 1 As shown, in order to effectively recycle the extractant, the glufosinate hydrolysis low-boiling product separation and recovery device also includes a fourth distillation column 5. The fourth distillation column 5 has a fourth feed port 51 suitable for introducing the third bottom liquid and a fourth distillate outlet 52 suitable for distilling the fourth distillate. The fourth feed port 51 is connected to the third bottom liquid outlet 43, and the fourth distillate outlet 52 is connected to the extractant inlet 32.

[0051] Specifically, such as Figure 1 As shown, the fourth distillation column 5 also has a fourth bottom liquid outlet 53 suitable for collecting the fourth bottom liquid.

[0052] In this embodiment, the first distillation column 1, the second distillation column 3, the third distillation column 4, and the fourth distillation column 5 may also include a reboiler located at the bottom of the column to heat the medium inside the column, and may also include a reflux structure for reflux of the distillate from the top of the column (not shown in the figure). Of course, they are also equipped with packing material, which are all prior art and will not be described in detail in this embodiment.

[0053] Specifically, in this embodiment, the hydrolyzed low-boiling product includes ethanol, ethyl acetate, cyanide, hydrochloric acid, etc. After distillation separation in the first distillation column 1, the first distillate includes ethanol, ethyl acetate, water, and cyanide, and the first bottom liquid is dilute hydrochloric acid. After distillation separation in the second distillation column 3, the second distillate is ethyl acetate, and the second bottom liquid includes ethanol and an extractant. After distillation separation in the third distillation column 4, the third distillate is ethanol, and the third bottom liquid is an extractant solution. After distillation separation in the fourth distillation column 5, the fourth distillate is an extractant, and the fourth bottom liquid is wastewater. In addition, in this embodiment, the extractant can be ethylene glycol, but other extractants can also be used.

[0054] Specifically, such as Figure 1 As shown, pumps 7 are installed between the first bottom liquid outlet 12 and the inlet of the concentration tower 6, between the liquid outlet 22 and the second inlet 31, between the second bottom liquid outlet 34 and the third inlet 41, and between the third bottom liquid outlet 43 and the fourth inlet 51 for material extraction.

[0055] Specifically, such as Figure 1 As shown, in order to effectively utilize the first bottom liquid (including dilute hydrochloric acid), the glufosinate hydrolysis low-boiling-point separation and recovery unit also includes a concentration tower 6, the inlet of which is connected to the outlet 12 of the first bottom liquid. Approximately 15% dilute hydrochloric acid can be collected from the outlet 12 of the first bottom liquid of the first distillation column 1 via pump 7, concentrated in the concentration tower 6 until the hydrochloric acid content reaches 30%, and then reused in the original hydrolysis reaction.

[0056] Specifically, such as Figure 1 As shown, the cyanide-breaking reactor 2 has a liquid alkali inlet 23 suitable for introducing liquid alkali.

[0057] Specifically, such as Figure 1 As shown, the cyanide-breaking reactor 2 has a sodium hypochlorite inlet 24 suitable for introducing sodium hypochlorite.

[0058] In this embodiment, liquid alkali is introduced into the reactor through liquid alkali inlet 23, and sodium hypochlorite is introduced into the reactor through sodium hypochlorite inlet 24. Inside the reactor, a small amount of liquid alkali is added to the first distillate solution to adjust the pH of the solution to 9-10, and then a small amount of sodium hypochlorite is added to carry out cyanide removal treatment.

[0059] Furthermore, such as Figure 1As shown, in order to condense the first distillate, a first condenser 81 suitable for condensing the first distillate is connected between the first distillate outlet 13 and the distillate inlet 21.

[0060] Furthermore, such as Figure 1 As shown, in order to condense the fourth distillate, i.e. the extractant, and reuse it in the second distillation column 3, a second condenser 82 suitable for condensing the fourth distillate is connected between the fourth distillate outlet 52 and the extractant inlet 32.

[0061] Furthermore, such as Figure 1 As shown, in order to store the second distillate (ethyl acetate) well, the glufosinate hydrolysis low-boiling product separation and recovery device also includes a first storage tank 91, which is connected to the second distillate outlet 33 and is suitable for storing the second distillate; of course, a third condenser 83 can also be set between the first storage tank 91 and the second distillate outlet 33 to condense the second distillate and store it in the first storage tank 91.

[0062] Furthermore, in order to better store the third distillate (ethanol), the glufosinate hydrolysis low-boiling product separation and recovery device also includes a second storage tank 92, which is connected to the third distillate outlet 42 and is suitable for storing the third distillate; of course, a fourth condenser 84 can also be installed between the second storage tank 92 and the third distillate outlet 42 to condense the third distillate and store it in the second storage tank 92.

[0063] In this embodiment, a hydrolyzed low-boiling product (containing ethanol, ethyl acetate, cyanide, and hydrochloric acid) at 90°C is continuously fed into the first distillation column 1. The first distillation column 1 operates at atmospheric pressure with a reflux ratio of 0.2, a top temperature of 83°C, and a bottom temperature of 105°C. The first distillate (containing ethanol, ethyl acetate, water, and cyanide) is collected from the first distillate outlet 13 at the top of the column, cooled, and fed into the cyanide-breaking reactor 2. The bottom liquid from the first reactor at 105°C is fed into the concentration column 6. After condensation, the first distillate enters the cyanide-breaking reactor 2, where a small amount of liquid alkali is added to adjust the pH of the solution to 9-10. A small amount of sodium hypochlorite is also added to break down the cyanide. The liquid after cyanide-breaking treatment is transferred from the liquid outlet 22 at 67°C using pump 7 into the second distillation column 3. An extractant is added to the second distillation column 3, which is used to recover ethyl acetate. The second distillation column 3 operates at atmospheric pressure with a reflux ratio of 1 and a top temperature of 77°C. At a bottom temperature of 98.5℃, 99% ethyl acetate is collected from the second distillate outlet 33 at the top of the column. After cooling, it enters the first storage tank 91 to store 99% ethyl acetate. Ethanol and the extractant solution, i.e., the second bottom liquid, can be transferred to the third distillation column 4 by pump 7. The third distillation column 4 is an ethanol column. The third distillation column 4 operates at atmospheric pressure with a reflux ratio of 1. The top temperature of the column is 57℃ and the bottom temperature is 122℃. 99% ethanol is collected from the third distillate outlet 42 at the top of the column. After cooling, it enters the second storage tank 92 to store 99% ethanol. The extractant solution, i.e., the third bottom liquid, can be transferred to the fourth distillation column 5 by pump 7. The fourth distillation column 5 is an extractant distillation column. The fourth distillation column 4 operates at atmospheric pressure with a reflux ratio of 1. The top temperature of the column is 52℃. The extractant is collected from the fourth distillate outlet 52 at the top of the column. After cooling, it returns to the second distillation column 3 for recycling. The fourth bottom liquid is the product wastewater.

[0064] The specific embodiments described above further illustrate the technical problems, technical solutions, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for separating and recovering low-boiling-point substances from glufosinate hydrolysis, characterized in that, include: The first distillation column has a first feed inlet suitable for introducing hydrolyzed low-boiling substances, a first bottom liquid outlet suitable for extracting first bottom liquid, and a first distillate outlet suitable for distilling first distillate. A cyanide-breaking reactor, wherein the cyanide-breaking reactor has a distillate inlet suitable for introducing the first distillate after condensation and a liquid outlet suitable for discharging the liquid after cyanide-breaking treatment; The second distillation column has a second feed inlet suitable for introducing the liquid after cyanide decomposition treatment, an extractant inlet suitable for introducing the extractant, a second distillate outlet suitable for distilling out the second distillate, and a second bottom liquid outlet suitable for collecting the second bottom liquid. The second feed inlet is connected to the liquid outlet. The third distillation column has a third feed inlet suitable for introducing the second bottom liquid, a third distillate outlet suitable for distilling the third distillate, and a third bottom liquid outlet suitable for collecting the third bottom liquid. The third feed inlet is connected to the second bottom liquid outlet.

2. The glufosinate hydrolysis low-boiling-point separation and recovery device according to claim 1, characterized in that: It also includes a concentration tower, the inlet of which is connected to the outlet of the first bottom liquid.

3. The glufosinate hydrolysis low-boiling-point separation and recovery device according to claim 1, characterized in that: The cyanide-breaking reactor has a liquid alkali inlet suitable for introducing liquid alkali; And / or the cyanide-breaking reactor has a sodium hypochlorite inlet suitable for introducing sodium hypochlorite.

4. The glufosinate hydrolysis low-boiling-point separation and recovery device according to claim 1, characterized in that: A first condenser suitable for condensing the first distillate is connected between the first distillate outlet and the distillate inlet.

5. The glufosinate hydrolysis low-boiling-point separation and recovery device according to claim 1, characterized in that: It also includes a fourth distillation column, which has a fourth feed inlet suitable for introducing the third bottom liquid and a fourth distillate outlet suitable for distilling a fourth distillate. The fourth feed inlet is connected to the outlet of the third bottom liquid, and the fourth distillate outlet is connected to the extractant inlet.

6. The glufosinate hydrolysis low-boiling-point separation and recovery device according to claim 5, characterized in that: A pump is provided between the liquid outlet and the second inlet and / or between the second bottom liquid outlet and the third inlet and / or between the third bottom liquid outlet and the fourth inlet.

7. The glufosinate hydrolysis low-boiling-point separation and recovery device according to claim 5, characterized in that: A second condenser suitable for condensing the fourth distillate is connected between the fourth distillate outlet and the extractant inlet.

8. The glufosinate hydrolysis low-boiling-point separation and recovery device according to claim 1, characterized in that: It also includes a first storage tank, which is connected to the outlet of the second distillate and is suitable for storing the second distillate or the condensed second distillate; And / or may also include a second storage tank connected to the outlet of the third distillate, suitable for storing the third distillate or the condensed third distillate.

9. A recovery method for a glufosinate hydrolysis low-boiling-point substance separation and recovery device as described in any one of claims 1 to 8, characterized in that, The steps of the method include: The hydrolyzed low-boiling product is continuously fed into the first distillation column for the first distillation, producing the first distillate and the first bottom liquid. The first distillate is condensed and sent to a cyanide-crushing reactor for cyanide-crushing treatment, producing a cyanide-crushed liquid. The liquid after cyanide destruction is sent to a second distillation column containing an extractant for a second distillation to produce a second distillate and a second bottom liquid. The second bottom liquid is fed into the third distillation column for a third distillation, producing the third distillate and the third bottom liquid. The third bottom liquid is fed into the fourth distillation column for a fourth distillation, producing a fourth distillate and a fourth bottom liquid. The fourth distillate is returned to the second distillation column as an extractant for recycling. The hydrolyzed low-boiling products contain ethanol, ethyl acetate, cyanide, and hydrochloric acid; The first distillate contains ethanol, ethyl acetate, and cyanide. The second distillate was ethyl acetate; The third distillate is ethanol; The fourth distillate is the extractant.

10. The recycling method according to claim 9, characterized in that, The first distillation column operates at atmospheric pressure with a reflux ratio of 0.2, a top temperature of 83°C, and a bottom temperature of 105°C. The second distillation column is operated at atmospheric pressure with a reflux ratio of 1, a top temperature of 77°C, and a bottom temperature of 98.5°C. The third distillation column is operated at atmospheric pressure with a reflux ratio of 1, a top temperature of 57°C, and a bottom temperature of 122°C. The fourth distillation column is operated at atmospheric pressure with a reflux ratio of 1 and a top temperature of 52°C.

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