Gas field water bromine extraction device

Abstract

The utility model relates to the technical field of gas field water treatment and bromine extraction devices, and particularly discloses a gas field water bromine extraction device which comprises an electrooxidation unit, a bromine storage tank, a blow-off tower, a chlorine washing tower, an absorption unit with an injection port, an evaporation centrifugal unit and a demisting tower connected with the absorption unit and the blow-off tower respectively, the electrooxidation unit is externally connected with a raw water tank; the demisting tower and the electrooxidation unit are respectively connected with the raw water tank. According to the device disclosed by the utility model, chlorine oxidation is replaced by electrooxidation, so that a hazardous chemical substance C l2 is prevented from being used in the oxidation process, and meanwhile, the product can be a derivative such as sodium bromide.

Description

Technical Field

[0001] This utility model relates to the technical field of gas field water treatment and bromine extraction equipment, and more specifically, to a gas field water bromine extraction equipment. Background Technology

[0002] Bromine has a certain solubility in gas field water. High concentrations of bromide released into the environment may negatively impact aquatic ecosystems, potentially causing toxic effects on aquatic organisms through bioaccumulation and food chain amplification. Furthermore, bromide in gas field water can be converted into bromine gas under certain conditions, posing a potential hazard to both aquatic and terrestrial organisms. Many countries and regions have specific regulations on bromide discharge concentrations in their water quality standards. For example, the U.S. Environmental Protection Agency (EPA) sets a maximum contaminant level (MCL) of 0.01 mg / L for bromide in drinking water. If the bromide content in gas field water exceeds national standards, direct discharge will cause serious environmental pollution, affecting ecological balance and human health. Therefore, effective measures need to be taken to treat gas field water for bromine removal before it is discharged in compliance with standards.

[0003] Bromine, as an important resource, has high economic value. In the chemical industry, bromine can be used to produce brominated flame retardants, brominated plasticizers, and brominated alcohols. These chemicals play a vital role in the production of plastics, rubber, and electronics, improving product safety and performance stability. In pesticides, bromine compounds can be used to produce fungicides, insecticides, and herbicides, effectively controlling crop diseases and pests and increasing agricultural yields. In pharmaceuticals, bromine and its compounds can be used to produce anti-infective drugs, sedatives, and disinfectants, playing a vital role in maintaining human health. In water treatment and disinfection, bromine is widely used in water treatment, disinfection, and purification. Bromine disinfectants are highly efficient, broad-spectrum, and long-lasting, effectively killing bacteria, viruses, and algae, maintaining clean and safe water quality. In lighting technology, bromine can be used to produce lighting gases and phosphors, improving the brightness and stability of lighting equipment. In display technology, bromides can be used to produce liquid crystal displays and other electronic displays, enhancing display effects and image quality. Extracting bromine from gas field water can meet market demand and generate economic benefits. At the same time, the utilization of associated water resources in gas fields also helps to achieve sustainable development and recycling of resources.

[0004] Traditional bromine extraction processes involve the oxidation of bromine with chlorine gas; see process details below. Figure 1 This process is primarily used to extract bromine from bromine-containing brine in salt lakes, seawater, or gas field water. Both chlorine and bromine are listed as hazardous chemicals in the "List of Hazardous Chemicals (2022 Edition)". Therefore, the production process using Cl2 oxidation to produce Br2 falls under the category of hazardous chemical production and storage projects. The basic principle of this process is to use chlorine as an oxidant to oxidize bromine (Br2) in water.- The chlorine gas is oxidized to bromine gas (Br2), and then bromine is extracted from the bromine gas through absorption and distillation. During the bromine extraction process, chlorine gas (Cl2) reacts with bromides to produce bromine gas (Br2) and chloride ions (Cl-). - The reaction equation is: 2Br - +Cl₂→2Cl - +Br2. Although this process is widely used, many problems still exist in the actual production of bromine extraction from gas field water: 1. Chlorine is a toxic gas and a hazardous chemical. If it is used in production, the storage and use of hazardous chemicals must be reported in advance, and the amount of chlorine used and the reaction conditions must be strictly controlled. Excessive chlorine will damage the environment and equipment, and harm human health. 2. The chlorine-containing wastewater generated in the process also requires deep treatment, which is costly and difficult. 3. The chlorine-to-bromine extraction process requires a large amount of energy for bromine evaporation and concentration, resulting in high energy costs and insufficient resource utilization. Due to the constraints of hazardous chlorine and other considerations, the traditional chlorine oxidation bromine extraction process cannot be applied to some high-bromine gas field water. Other processes that use hazardous chlorine as an oxidant and produce hazardous bromine must be avoided. Other methods should be adopted to achieve comprehensive utilization of bromine resources in gas field water.

[0005] Electro-oxidative bromine extraction technology is based on Br - With C - The difference in standard redox potentials allows for the selection of appropriate working electrode potentials to control Br. - Selective oxidation and extraction. Because the standard redox potential of Br- is higher than that of Cl-... - The voltage is 0.271V lower. When the working electrode potential is controlled between 1.087 and 1.358V, that is, when the working electrode potential is higher than Br... - The standard redox potential is lower than that of Cl. - At the standard redox potential, the Br in the solution - It can be oxidized and Cl - It cannot be oxidized, thus achieving Br - Selective electro-oxidation. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a bromine extraction device for gas field water; it uses electro-oxidation instead of chlorine oxidation, which avoids the use of hazardous chemical Cl2 in the oxidation process, while the product can be a derivative such as sodium bromide.

[0007] The solution adopted by this utility model to solve the technical problem is:

[0008] A bromine extraction device for gas field water, connected to a raw water tank; comprising, in sequence, an electro-oxidation unit, a bromine storage tank, a blowing tower, a chlorine washing tower, an absorption unit with an injection port, an evaporation centrifugation unit, and a demister connected to the absorption unit and the blowing tower respectively; the electro-oxidation unit is externally connected to the raw water tank;

[0009] The demister and electro-oxidation unit are connected to the raw water tank respectively; the chlorine washing tower is connected to the waste brine tank, and a waste brine pump is installed between the waste brine tank and the raw water tank.

[0010] The gas field water is first pumped to the raw water tank for storage, then pumped to the electro-oxidation unit for electro-oxidation. The generated bromine is stored in the bromine storage tank, and then blown out to the chlorine washing tower via the blow-out tower. The dechlorinated bromine gas phase enters the absorption unit for absorption. The gas phase absorbed by the absorption unit is dehydrated by the demister tower and then circulated back into the blow-out tower by the blower. The liquid phase absorbed by the absorption tower is pumped to the evaporation centrifuge. After evaporation centrifugation, sodium bromide solid is produced. The debrominated gas field water is returned to the chlorine washing tower.

[0011] In some possible implementations, a waste brine tank is also included, which is connected to the demister and the raw water tank respectively.

[0012] In some possible implementations, a dosing tank connected to the injection port of the absorption unit is also included.

[0013] In some possible implementations, the absorption unit includes a primary absorption tower connected to the chlorine washing tower and the evaporation centrifuge unit, respectively, and a secondary absorption tower connected to the primary absorption tower, the evaporation centrifuge unit, and the demister tower, respectively.

[0014] In some possible implementations, the evaporation centrifugation unit includes an evaporator connected to a primary absorption tower and a secondary absorption tower, respectively, and a centrifuge connected to the evaporator; the centrifuge is connected to a chlorine washing tower.

[0015] In some possible implementations, a mother liquor tank is provided between the centrifuge and the chlorine washing tower, and is connected to both the centrifuge and the chlorine washing tower respectively; a submersible pump is provided between the mother liquor tank and the chlorine washing tower.

[0016] In some possible implementations, a brine pump assembly is provided between the bromine storage tank and the blow-out tower; the output end of the brine pump assembly is connected to the top of the blow-out tower.

[0017] In some possible implementations, a sodium bromide pump assembly is provided on the outside of the chlorine washing tower; the input end of the sodium bromide pump assembly is connected to the bottom of the chlorine washing tower, and the output end of the sodium bromide pump assembly is connected to the top of the chlorine washing tower.

[0018] In some possible implementations, absorption pump assemblies are respectively provided on the outside of the primary absorption tower and the secondary absorption tower; the input end of the absorption pump assembly is connected to the bottom of the primary absorption tower or the secondary absorption tower, and the output end of the absorption pump assembly is connected to the top of the primary absorption tower or the secondary absorption tower.

[0019] In some possible implementations, a fan is provided between the demister and the blow-out tower, and the output end of the fan is connected to the bottom of the blow-out tower.

[0020] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0021] This invention selectively extracts and absorbs bromine through electro-oxidation, ultimately yielding sodium bromide for comprehensive utilization. It innovates a "self-production and self-sales" bromine extraction method, while also having relatively lower investment and energy consumption. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of this utility model;

[0023] In the middle section: 1. Raw water tank; 2. Electro-oxidation unit; 3. Bromine storage tank; 4. Blowout tower; 41. Brine pump assembly; 5. Chlorine washing tower; 51. Sodium bromide pump assembly; 6. Absorption unit; 60. Dosing tank; 61. Primary absorption tower; 62. Secondary absorption tower; 611. Absorption pump assembly; 7. Evaporation and centrifugation unit; 71. Evaporation kettle; 72. Centrifuge; 73. Mother liquor tank; 74. Submersible pump; 8. Demisting tower; 81. Fan; 9. Waste brine tank; 91. Waste brine pump. Detailed Implementation

[0024] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. The terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "a" or "one," etc., do not indicate a quantity limitation, but rather indicate the existence of at least one. In the implementation of this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more. For example, multiple positioning posts refer to two or more positioning posts. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0025] The present invention will now be described in detail.

[0026] like Figure 1 As shown:

[0027] A bromine extraction device for gas field water is connected to a raw water tank 1. It includes, in sequence, an electro-oxidation unit 2, a bromine storage tank 3, a blowing tower 4, a chlorine washing tower 5, an absorption unit 6 with an injection port, an evaporation centrifugation unit 7, a demisting tower 8 connected to the absorption unit 6 and the blowing tower 4 respectively, and a waste brine tank 9 connected to the demisting tower 8 and the raw water tank 1 respectively. The chlorine washing tower 5 is connected to the waste brine tank 9, and a waste brine pump 91 is installed between the waste brine tank 9 and the raw water tank 1. The electro-oxidation unit 2 is externally connected to the raw water tank 1. The chlorine washing tower 5 stores sodium bromide solution. The waste brine tank 9 and the electro-oxidation unit 2 are respectively connected to the raw water tank 1.

[0028] Gas field water is pumped to raw water tank 1 for storage, and then pumped to electro-oxidation unit 2 for electro-oxidation. The generated bromine is stored in bromine storage tank 3, and then blown out to chlorine washing tower 5 via blowout tower 4. The dechlorinated bromine gas phase enters absorption unit 6 for absorption. The gas phase absorbed by absorption unit 6 is dehydrated by demister tower 8 and then enters blowout tower 4 for circulation via blower 81. The liquid phase absorbed by absorption tower is pumped to evaporation and centrifugation unit 7. After evaporation and centrifugation, sodium bromide solid is produced. The debrominated gas field water is returned to chlorine washing tower 5.

[0029] Specifically, when the electro-oxidation unit 2 is operating, the electro-oxidation working electrode potential is controlled between 1.087 and 1.358 V. When Br - The oxidation reaction is completed when the content is below 0.7 g / L.

[0030] Since the gas field water contains a small amount of residual chlorine, a small amount of chlorine gas may be generated during the electro-oxidation process in electro-oxidation unit 2. The sodium bromide solution in chlorine washing tower 5 removes the chlorine gas through a displacement reaction, generating more bromine gas. The bromine is selectively extracted and absorbed through electro-oxidation, and finally sodium bromide product is obtained for recycling, which has good advantages in energy saving and environmental protection.

[0031] This invention prioritizes energy conservation and environmental protection. It employs electro-oxidation to avoid the use of hazardous chlorine gas during the oxidation process, while producing sodium bromide and other derivatives. By optimizing the electro-oxidation process and combining the functional characteristics of the blowing tower 4, chlorine washing tower 5, absorption unit 6, and demister tower 8, an innovative "self-production and self-consumption" bromine extraction method is developed. The bromine generated by the electro-oxidation reaction is absorbed in the absorption unit within the device, ultimately yielding sodium bromide. This device uses electro-oxidation to extract bromine, avoiding the use of hazardous chlorine gas. Furthermore, the sodium bromide product obtained through blowing, chlorine washing, absorption, evaporation, and crystallization is recycled and reused. This achieves comprehensive utilization of associated resources while purifying gas field water, demonstrating green and environmentally friendly characteristics in energy recovery.

[0032] In some possible embodiments, a dosing tank 60 connected to the injection port of the absorption unit 6 is also included; the dosing tank 60 stores a mixed solution formed by urea and alkaline solution, specifically the alkaline solution can be a 15% mass concentration NaOH solution, the urea is a 45% mass concentration urea solution, and the mass ratio of NaOH solution to urea solution is 4:1.

[0033] In some possible implementations, the absorption unit 6 includes a primary absorption tower 61 connected to the chlorine washing tower 5 and the evaporation centrifuge unit 7, respectively, and a secondary absorption tower 62 connected to the primary absorption tower 61, the evaporation centrifuge unit 7, and the demister tower 8, respectively.

[0034] The secondary absorption tower 62 serves as a backup tower. Liquid level monitoring components are installed on both the primary absorption tower 61 and the secondary absorption tower 62. These components control the liquid levels in both towers. The liquid phase generated after absorption by either the primary or secondary absorption tower 61 enters the evaporation centrifuge unit 7 for evaporation and centrifugation to obtain sodium bromide solid. The gas phase generated after absorption by either the primary or secondary absorption tower 62 enters the demister tower 8, where it undergoes dehydration treatment. The gas phase then enters the blow-out tower 4 for recycling. The waste brine generated after treatment by the demister tower 8 enters the waste brine tank 9 and is pumped into the raw water tank 1 via the waste brine pump 91.

[0035] In some possible implementations, the evaporation centrifugation unit 7 includes an evaporation vessel 71 connected to a primary absorption tower 61 and a secondary absorption tower 62, and a centrifuge 72 connected to the evaporation vessel 71; a mother liquor tank 73 is provided between the centrifuge 72 and the chlorine washing tower 5, and is connected to both the centrifuge 72 and the chlorine washing tower 5; a submersible pump 74 is provided between the mother liquor tank 73 and the chlorine washing tower 5.

[0036] The centrifuge 72 is connected to the chlorine washing tower 5; the liquid phase after the reaction in the absorption unit 6 enters the evaporation kettle 71 for evaporation treatment, and then enters the centrifuge 72 for centrifugation treatment to obtain 45% sodium bromide product. The resulting liquid (sodium bromide) enters the mother liquor tank 73, and then is transported to the chlorine washing tower 5 for use by the submersible pump 74.

[0037] In some possible implementations, a brine pump assembly 41 is provided between the bromine storage tank 3 and the blowing tower 4; the output end of the brine pump assembly 41 is connected to the top of the blowing tower 4; the brine pump assembly 41 is connected to the bottom of the blowing tower 4.

[0038] The bromine stored in the bromine storage tank 3 enters the blow-out tower 4 through the brine pump assembly 41, and the bromine gas is blown off by the blow-out tower 4 to the chlorine washing tower 5.

[0039] In some possible implementations, a sodium bromide pump assembly 41 is provided on the outside of the chlorine washing tower 5; the input end of the sodium bromide pump assembly 41 is connected to the bottom of the chlorine washing tower 5, and the output end of the sodium bromide pump assembly 41 is connected to the top of the chlorine washing tower 5. The elemental bromine in the bromine storage tank 3 is transported to the top of the blow-out tower 4 through the brine pump assembly 41.

[0040] In some possible implementations, absorption pump assemblies 611 are respectively provided on the outside of the primary absorption tower 61 and the secondary absorption tower 62; the input end of the absorption pump assembly 611 is connected to the bottom of the primary absorption tower 61 or the secondary absorption tower 62, and the output end of the absorption pump assembly 611 is connected to the top of the primary absorption tower 61 or the secondary absorption tower 62.

[0041] Each absorption pump assembly 611 includes two absorption pump bodies arranged in parallel. One end of the pump is connected to the bottom of the corresponding absorption tower (first-stage absorption tower 61 or second-stage absorption tower 62), and the other end is connected to the top of the absorption tower (first-stage absorption tower 61 or second-stage absorption tower 62). The absorption pump body is also connected to the evaporation centrifugal unit 7.

[0042] The brine pump assembly 41 includes two sets of brine pump bodies arranged in parallel, one end of which is connected to the bottom of the blow-out tower 4 and the bromine storage tank 3, and the other end is connected to the top of the blow-out tower 4.

[0043] The sodium bromide pump assembly 51 includes two sets of pump bodies arranged in parallel; one end is connected to the bottom of the chlorine washing tower 5, and the other end is connected to the top of the chlorine washing tower 5.

[0044] The gas phase after the reaction in the chlorine washing tower 5 enters the primary absorption tower 61, where it undergoes a thorough mixing reaction under the action of the absorption pump assembly 611. When the required pH value is reached (pH value reaches 8), the absorption pump assembly 611 transports the mixed liquid to the evaporation centrifuge unit 7 to obtain 45% sodium bromide product. The gas phase generated after the reaction then enters the demister tower 8.

[0045] In some possible implementations, a fan 81 is provided between the demister 8 and the blow-out tower 4. The output end of the fan 81 is connected to the bottom of the blow-out tower 4. The gas phase after water removal treatment by the demister 8 enters the blow-out tower 4 through the fan 81. The elemental bromine in the bromine storage tank 3 is blown out through the gas phase into the chlorine washing tower 5 to react with the sodium bromide solution in the chlorine washing tower 5.

[0046] The bromine storage tank 3 is equipped with a liquid level testing component. When the liquid level in the bromine storage tank 3 reaches 1.5m, the component is activated. Bromine enters the top of the blow-out tower 4 through the brine pump component and enters the blow-out tower 4 under the action of the blower 81. The bromine gas is blown off by the blow-out tower 4 and sent to the chlorine washing tower 5, where it mixes with the sodium bromide solution in the chlorine washing tower 5. Then, it enters the absorption tower for absorption. When the pH value in the absorption tower reaches about 8.0, the absorption pump component 611 sends the qualified solution to the evaporation kettle 71 for evaporation and centrifugation to obtain 45% sodium bromide product.

[0047] The absorption pump assembly 611 will circulate the solution in the absorption tower (primary absorption tower 61, secondary absorption tower 62), and deliver the liquid that meets the requirements to the evaporation unit and the gas phase to the demister tower 8.

[0048] Specifically, after the sodium bromide solution in the chlorine washing tower 5 has been completely converted into sodium chloride solution, and the bromine content is determined to be 0.5-0.8 g / L through sampling analysis, the sodium bromide solution in the chlorine washing tower 5 is discharged into the waste brine tank 9, and then transported to the raw water tank 1 through the waste brine pump 91.

[0049] Taking a gas field water as an example, laboratory analysis shows that when the oxidation rate is 98%, the COD content of the gas field water can be reduced to 80 mg / L, the ammonia nitrogen content can be reduced to 150 mg / L, the electricity consumption per ton of water is 3.83 kWh, and the electricity cost per ton of water is calculated at 0.6 yuan. The electricity cost per ton of water is 2.298 yuan, and the electricity cost to produce one ton of sodium bromide is 3986 yuan.

[0050] This invention is not limited to the specific embodiments described above. This invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A gas field water bromine extraction unit characterized in that, The device comprises an electric oxidation unit, a bromine storage tank, a blowing tower, a chlorine washing tower, an absorption unit provided with an injection port, an evaporation centrifugal unit, and a demisting tower connected with the absorption unit and the blowing tower respectively; the electric oxidation unit is externally connected with a raw water tank; The demisting tower and the electric oxidation unit are connected with the raw water tank respectively.

2. A gas field water bromine extraction unit according to claim 1, characterized in that, Further comprising a waste brine tank connected with the demisting tower and the raw water tank respectively.

3. A gas field water bromine extraction unit according to claim 1, characterized in that, Further comprising a dosing tank connected with the injection port of the absorption unit.

4. A gas field water bromine extraction unit according to claim 1, characterized in that, The absorption unit comprises a first-stage absorption tower connected with the chlorine washing tower and the evaporation centrifugal unit respectively, and a second-stage absorption tower connected with the first-stage absorption tower, the evaporation centrifugal unit, and the demisting tower respectively.

5. A gas field produced water bromide extraction unit according to claim 4 wherein, The evaporation centrifugal unit comprises an evaporation kettle connected with the first-stage absorption tower and the second-stage absorption tower respectively, and a centrifugal machine connected with the evaporation kettle; the centrifugal machine is connected with the chlorine washing tower.

6. A gas field produced water bromide extraction unit according to claim 5 wherein, A mother liquor tank in communication with the centrifugal machine and the chlorine washing tower is arranged between the centrifugal machine and the chlorine washing tower; a submersible pump is arranged between the mother liquor tank and the chlorine washing tower.

7. A gas field water bromine extraction unit as claimed in claim 1, wherein, A brine pump assembly is arranged between the bromine storage tank and the blowing tower; an output end of the brine pump assembly is connected with a top of the blowing tower.

8. A gas field water bromine extraction unit according to claim 1, characterized in that, A sodium bromide pump assembly is arranged outside the chlorine washing tower; an input end of the sodium bromide pump assembly is in communication with a bottom of the chlorine washing tower, and an output end of the sodium bromide pump assembly is in communication with a top of the chlorine washing tower.

9. A gas field produced water bromide extraction unit according to claim 3 wherein, An absorption pump assembly is arranged outside the first-stage absorption tower and the second-stage absorption tower respectively; an input end of the absorption pump assembly is in communication with a bottom of the first-stage absorption tower or the second-stage absorption tower, and an output end of the absorption pump assembly is in communication with a top of the first-stage absorption tower or the second-stage absorption tower.

10. A gas field produced water bromide extraction unit according to claim 1 wherein, A fan is arranged between the demisting tower and the blowing tower; an output end of the fan is connected with a bottom of the blowing tower.

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