Device and method for treating high-COD (Chemical Oxygen Demand) organic wastewater in 1-chlorobutane production process

Abstract

The invention relates to a device and a method for treating high-COD (Chemical Oxygen Demand) organic wastewater in a 1-chlorobutane production process. The device comprises a wastewater storage tank, a stripping tower, a reboiler, a first graphite condenser, a stripping organic phase storage tank, a second graphite condenser and a process water storage tank, a water outlet of the wastewater storage tank is connected with a feeding hole of the stripping tower through a first fluorine lining pipe; the lower part of the stripping tower is connected with a reboiler through a pipeline, the bottom of the stripping tower and the bottom of the reboiler are respectively connected with a feed port of a second graphite condenser through a second fluorine-lined pipe, and a discharge port of the stripping tower is connected with a feed port of the first graphite condenser through a third fluorine-lined pipe; a discharging hole of the first graphite condenser is connected with a feeding hole of the stripping organic phase storage tank through a pipeline; and the discharge port of the second graphite condenser is connected with the feed port of the process water storage tank through a pipeline. According to the method, the COD removal rate can be increased without adding extra chemical reagents, secondary wastewater cannot be generated, and the required equipment and method are simple and efficient.

Description

Technical Field

[0001] The invention belongs to the field of chemical organic wastewater treatment, and specifically relates to a method and a device for treating organic wastewater generated in the production process of 1-chlorobutane. Background Art

[0002] With the development of social economy, industrial pollution has also intensified, and the increase in the amount of industrial sewage and wastewater is the most prominent, among which high COD organic wastewater is the most discharged. High COD organic wastewater refers to industrial wastewater with a chemical oxygen demand concentration of more than 3000 mg / L. It usually has the characteristics of high color, strong odor, poor biodegradability, strong corrosiveness, and difficulty in treatment. It must be treated before it can be discharged or reused.

[0003] A large amount of high COD organic wastewater is generated during the production of 1-chlorobutane. Traditional methods for treating high COD organic wastewater include physical methods, chemical methods, and biological methods. The physical method uses precipitation, filtration, and flotation methods for treatment, which have the disadvantages of large site occupation, long process, low efficiency, high production cost, and environmental pollution. The chemical method mainly uses oxidation-reduction, chemical precipitation, and coagulation methods. Although its treatment efficiency is high, it requires the addition of additional chemical reagents. For example, Chinese patent application CN118579916A discloses a method for treating organic wastewater, first adding acid to industrial organic wastewater to adjust the pH to 3.8-5.5, then adding sodium dimethyldithiocarbamate, sodium diethyldithiocarbamate, trisodium thiocyanate, sodium piperazinedithiocarbamate and other reagents to the acidic wastewater for stirring reaction, and after standing, the treated industrial organic wastewater is obtained. Chinese patent CN104925997A discloses a method for treating organic wastewater with a recyclable catalyst, wherein the organic wastewater is treated in a weakly acidic environment, i.e., pH=4.0-6.0, with H2O2 as an oxidant, Cu 2+As a catalyst, the organic pollutants in the wastewater are oxidized and degraded. After the oxidation reaction is completed, acid is added to the reaction solution to adjust the pH value of the reaction solution to 2.0-4.0, and finally alkali is added to neutralize and precipitate to recover the catalyst. Chinese patent CN107473435A discloses a catalytic oxidation method for treating organic wastewater. Under normal temperature and pressure conditions, calcium hypochlorite + flocculant (polyacrylamide) is first used for enhanced flocculation, and then a certain concentration of ozone and a small amount of H2O2 are added. The catalytic oxidation is carried out using a honeycomb carrier catalyst loaded with precious metal elements such as Pt, Pd, Ru and transition metal elements such as Cu, Mn, Zn, Fe, and Co. Although the COD removal rate of this method is ≥95%, this catalytic oxidation method is limited to wastewater with a COD content of ≤1000 mg / L. Chinese patent application CN101774676A discloses a method for treating high COD industrial organic wastewater. The method is based on the principle of heterogeneous catalytic Fenton oxidation reaction, the active phase of the catalyst is Fe / Al composite oxide, the wastewater treatment temperature is 30-80℃, the pH value is 3-4.5, hydrogen peroxide (H2O2) is used as the oxidant, and hydrogen peroxide is added in different time periods. Chinese patent application CN116874109A discloses a method and device for treating industrial organic wastewater. First, the pretreatment component is used to soften, remove impurities and filter the salt-containing industrial wastewater to remove divalent hardness ions, suspended matter and colloidal pollutants; then the advanced oxidation component is used to intercept microorganisms and dissolved salts, colloids and organic matter in the wastewater to remove odors, and then the gas-liquid separation component is used to separate the wastewater into gas and liquid, so that the harmful gases in the wastewater are separated faster; finally, the electrodialysis component and the desalination component are used for desalination. The chemical method will not only cause more pollution, but also increase the difficulty of wastewater treatment and the production cost of the industry. The biological method mainly uses aerobic treatment, anaerobic treatment and biofilm methods, which have problems such as large investment in treatment equipment and high treatment cost. Summary of the invention

[0004] The purpose of the present invention is to solve the deficiencies of the prior art and to provide a 1-chlorobutane organic wastewater treatment device and method which can improve the COD removal rate in organic wastewater without adding additional chemical reagents during the treatment process, and will not generate secondary wastewater, and the required equipment and method are simple and efficient.

[0005] The technical solution adopted by the present invention is as follows: A high COD organic wastewater treatment device for a 1-chlorobutane production process comprises a wastewater storage tank, a stripping tower, a reboiler, a first graphite condenser, a stripping organic phase storage tank, a second graphite condenser and a process water storage tank; the water outlet at the bottom of the wastewater storage tank is connected to the feed port of the stripping tower through a first fluorine-lined pipe, and a feed pump, a flow meter and a pneumatic regulating valve are sequentially arranged on the first fluorine-lined pipe; the lower part of the stripping tower is connected to the reboiler through a pipeline, the bottom of the stripping tower and the bottom of the reboiler are respectively connected to the feed port of the second graphite condenser through a second fluorine-lined pipe, and the upper end discharge port of the stripping tower is connected to the feed port of the first graphite condenser through a third fluorine-lined pipe; the discharge port of the first graphite condenser is connected to the feed port of the stripping organic phase storage tank through a pipeline; the discharge port of the second graphite condenser is connected to the feed port of the process water storage tank through a pipeline.

[0006] Furthermore, the first graphite condenser and the second graphite condenser are provided with cooling circulating water jackets, the upper ends of the cooling circulating water jackets are provided with cooling circulating water outlets, and the lower ends are provided with cooling circulating water inlets.

[0007] Furthermore, a control valve and an arch bridge pipe connected before and after the control valve are arranged on the third fluorine-lined pipe, so that qualified water in the distillation tower can flow smoothly out of the arch bridge pipe and then enter the process water storage tank.

[0008] Furthermore, the tower body of the distillation tower is made of steel-lined PTFE and graphite, and has ceramic corrugated packing inside.

[0009] Furthermore, the reboiler is made of graphite.

[0010] The present invention discloses a method for treating high COD organic wastewater in a 1-chlorobutane production process, comprising the following steps: S1. The organic wastewater with a COD content of ≥6000 mg / L generated in the production process of 1-chlorobutane is sent to a wastewater storage tank, and the organic wastewater stored in the wastewater storage tank is transported into the distillation tower through a discharge pump, and the flow rate is displayed and controlled by a flow meter and a pneumatic regulating valve; S2. Start the reboiler to heat the organic wastewater in the distillation tower to 70 o C~110 o C, vaporizes the organic matter and then enters the first graphite condenser; S3. The steam containing the vaporized organic phase entering the first graphite condenser is condensed to obtain an organic phase, and the organic phase enters the stripping organic storage tank; S4. After the organic phase in the distillation tower is vaporized, the remaining water flows out from the arch bridge pipe and enters the second graphite condenser (10) through the fluorine-lined pipe for condensation to obtain low COD wastewater with a COD content of ≤300 mg / L. The wastewater enters the process water storage tank.

[0011] The device and method of the present invention make full use of the characteristics of volatile organic compounds such as alcohol and chlorobutane contained in high COD organic wastewater generated in the production process of 1-chlorobutane that are easily volatilized by heating. The high COD organic wastewater only needs to be pumped into a distillation tower and heated by a reboiler, and the hot steam is condensed and separated. Wastewater with a COD content of ≤300 mg / L can be obtained by heating, vaporizing, condensing and separating. The device is simple to set up, and the operation method is simple and efficient. The COD removal rate in the organic wastewater can be improved without adding additional chemical reagents during the treatment process, and no secondary wastewater is generated. The treated water resources can be recycled in industrial production, which is green and environmentally friendly, and reduces the cost of industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Schematic diagram of the device of the present invention.

[0013] Figure 1 :1-wastewater storage tank, 2-feed pump, 3-flow meter, 4-pneumatic regulating valve, 5-first fluorine-lined pipe, 6-distillation tower, 7-reboiler, 8-first graphite condenser, 9-stripping organic storage tank, 10-second graphite condenser, 11-process water storage tank, 12-second fluorine-lined pipe, 13-third fluorine-lined pipe, 14-arch bridge pipe, 15-control valve. DETAILED DESCRIPTION

[0014] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings.

[0015] like Figure 1As shown, a high COD organic wastewater treatment device for the production process of 1-chlorobutane includes a wastewater storage tank 1, a stripping tower 6, a reboiler 7, a first graphite condenser 8, a stripping organic phase storage tank 9, a second graphite condenser 10, and a process water storage tank 11. The water outlet at the bottom of the wastewater storage tank 1 is connected to the feed port of the stripping tower 6 through a first fluorine-lined pipe 5, and a feed pump 2, a flow meter 3, and a pneumatic regulating valve 4 are sequentially arranged on the first fluorine-lined pipe 5. The flow meter is used to display the feed flow rate, and the pneumatic regulating valve is used to adjust the feed flow rate. The lower part of the stripping tower 6 is connected to the reboiler 7 through a pipeline, and the bottom of the stripping tower and the bottom of the reboiler are respectively connected to the feed port of the second graphite condenser 10 through a second fluorine-lined pipe 12, and the upper end discharge port of the stripping tower is connected to the feed port of the first graphite condenser 8 through a third fluorine-lined pipe 13. The discharge port of the first graphite condenser 8 is connected to the feed port of the stripping organic phase storage tank 9 through a pipeline. The discharge port of the second graphite condenser 10 is connected to the feed port of the process water storage tank 11 through a pipeline. The first graphite condenser 8 and the second graphite condenser 10 are provided with cooling circulating water jackets, and the upper end of the cooling circulating water jacket is provided with a cooling circulating water outlet, and the lower end is provided with a cooling circulating water inlet. The third fluorine-lined pipe 13 is provided with a control valve 15 and an arch bridge pipe 14 connected to the front and rear of the control valve, and the arch bridge pipe 14 is a fluorine-lined pipe.

[0016] like Figure 1 As shown, the distillation tower 6 adopts existing technical equipment. This embodiment adopts the AD6K-300LBCP model distillation tower produced by Nantong Graphite Factory. The tower body is made of a combination of steel-lined PTFE and graphite. There is a ceramic corrugated packing in the tower. The ceramic corrugated packing is a special packing used for separation and mass transfer. It is made of high-purity ceramic material with a corrugated shape. This packing has many tiny pores and channels inside, which can increase the surface area and contact area, thereby improving the separation and mass transfer effects.

[0017] like Figure 1 As shown, the reboiler 7 adopts existing technical equipment. This embodiment adopts a YKC60-30 model reboiler produced by Nantong Graphite Factory, which is made of graphite.

[0018] The first graphite condenser 8 and the second graphite condenser 10 may be graphite condensers of the prior art.

[0019] The wastewater storage tank 1 and the stripping organic storage tank 9 are both enamel tanks with good corrosion resistance.

[0020] The first fluorine-lined tube 5 , the second fluorine-lined tube 12 , the third fluorine-lined tube 13 , and the arch bridge tube 14 are commercially available fluorine-lined pipes, which have good corrosion resistance.

[0021] use Figure 1The device shown in the figure is used to treat high COD organic wastewater in the 1-chlorobutane production process, and the specific steps are as follows: S1. The high COD organic wastewater generated in the production process of 1-chlorobutane is sent to the wastewater storage tank 1, wherein the high COD organic wastewater contains volatile organic matter such as alcohol and chlorobutane, and the COD content is usually 6000-25000 mg / L.

[0022] The organic wastewater stored in the wastewater storage tank is transported into the distillation tower 6 through the discharge pump, and the flow rate is displayed and controlled by the flow meter 3 and the pneumatic regulating valve 4; S2. Start the reboiler 7 to heat the organic wastewater in the distillation tower to 70 o C~110 o C, vaporizes the organic matter and then enters the first graphite condenser 8; S3. The steam containing the vaporized organic phase entering the first graphite condenser is condensed to obtain an organic phase, and the organic phase enters the stripping organic storage tank 9; S4. The remaining water after the organic phase in the distillation tower 6 is gasified comes out from the arch bridge pipe 14 and enters the second graphite condenser 10 through the fluorine-lined pipe 13 for condensation to obtain low-COD wastewater with a COD content of ≤300 mg / L, and the wastewater then enters the subsequent process water storage tank 11. The arch bridge pipe can prevent the high-COD organic wastewater that has just entered the distillation tower from flowing out into the process water storage tank together with the low-COD wastewater in the tower without being heated and evaporated. If the wastewater in the distillation tower directly comes out from the pneumatic valve 15 and enters the second graphite condenser through the fluorine-lined pipe 13, the high-COD organic wastewater that has just entered the distillation tower will flow out into the process water storage tank together with the low-COD wastewater in the tower without being heated and evaporated.

Claims

1. A high COD organic wastewater treatment device for 1-chlorobutane production process, characterized in that: The device comprises a wastewater storage tank (1), a stripping tower (6), a reboiler (7), a first graphite condenser (8), a stripping organic phase storage tank (9), a second graphite condenser (10), and a process water storage tank (11); the water outlet at the bottom of the wastewater storage tank (1) is connected to the feed port of the stripping tower (6) via a first fluorine-lined pipe (5), and a feed pump (2), a flow meter (3), and a pneumatic regulating valve (4) are sequentially arranged on the first fluorine-lined pipe (5); the lower part of the stripping tower (6) is connected to the reboiler (7); The stripping tower (7) is connected to the stripping organic phase storage tank (9) through a pipeline; the bottom of the stripping tower and the bottom of the reboiler are respectively connected to the feed port of the second graphite condenser (10) through a second fluorine-lined tube (12); the discharge port at the upper end of the stripping tower is connected to the feed port of the first graphite condenser (8) through a third fluorine-lined tube (13); the discharge port of the first graphite condenser (8) is connected to the feed port of the stripping organic phase storage tank (9) through a pipeline; and the discharge port of the second graphite condenser (10) is connected to the feed port of the process water storage tank (11) through a pipeline.

2. A high COD organic wastewater treatment device for 1-chlorobutane production process according to claim 1, characterized in that: The first graphite condenser (8) and the second graphite condenser (10) are provided with cooling circulating water jackets, the upper ends of the cooling circulating water jackets are provided with cooling circulating water outlets, and the lower ends of the cooling circulating water jackets are provided with cooling circulating water inlets.

3. A high COD organic wastewater treatment device for 1-chlorobutane production process according to claim 1, characterized in that: The third fluorine-lined pipe (13) is provided with a control valve (15) and an arch bridge pipe (14) connected to the front and rear of the control valve.

4. A high COD organic wastewater treatment device for 1-chlorobutane production process according to claim 1, 2 or 3, characterized in that: The body of the distillation tower (6) is made of steel-lined PTFE and graphite, and there is ceramic corrugated packing in the tower.

5. A high COD organic wastewater treatment device for 1-chlorobutane production process according to claim 1, 2 or 3, characterized in that: The material of the reboiler (7) is graphite.

6. The method for treating high COD organic wastewater from the 1-chlorobutane production process according to any one of claims 1 to 5, characterized in that: The steps are as follows: S1. Organic wastewater with a COD content of ≥6000 mg / L generated in the production process of 1-chlorobutane is sent to a wastewater storage tank (1). The organic wastewater stored in the wastewater storage tank is transported into a distillation tower (6) through a discharge pump, and the flow rate is displayed and controlled by a flow meter (3) and a pneumatic regulating valve (4); S2. Start the reboiler (7) to heat the organic wastewater in the distillation tower to 70 o C~110 o C, vaporizing the organic matter and then entering the first graphite condenser (8); S3. The steam containing the vaporized organic phase entering the first graphite condenser is condensed to obtain an organic phase, and the organic phase enters the stripping organic storage tank (9); S4. After the organic phase in the distillation tower (6) is vaporized, the remaining water comes out from the arch bridge pipe (14) and enters the second graphite condenser (10) through the fluorine-lined pipe (13) for condensation to obtain low-COD wastewater with a COD content of ≤300 mg / L and enters the process water storage tank (11).

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