CN-119118389-B - System and method for obtaining concentrated lithium from gas field produced water

Abstract

The invention belongs to the field of treatment of gas field produced water, and particularly relates to a system and a method for obtaining concentrated lithium from gas field produced water. The system for obtaining the concentrated lithium from the gas field produced water comprises an oxidation mechanism, a liquid film mechanism and a concentration mechanism which are sequentially connected, wherein the oxidation mechanism is used for carrying out oxidative degradation on the produced water, the liquid film mechanism is used for carrying out lithium selective extraction on the produced water after oxidative degradation, and the concentration mechanism is used for carrying out lithium concentration on the produced water after selective extraction. The system can realize the effective extraction and concentration of the lithium in the produced water, and improves the recovery rate of the lithium in the produced water.

Inventors

• WANG DAN
• WANG QINGJI
• WANG YILIN
• LUO ZHEN
• YANG XUEYING
• SUN XIUMEI

Assignees

• 中国石油天然气集团有限公司
• 中国石油集团安全环保技术研究院有限公司

Dates

Publication Date

20260508

Application Date

20230612

Claims (9)

1. 1. A method for obtaining concentrated lithium from field produced water, comprising the steps of: ozone is added to carry out oxidative degradation on the produced water; adding a liquid film to carry out lithium selective extraction treatment on the produced water after oxidative degradation; Concentrating lithium in the extracted water after selective extraction; The preparation method of the liquid film comprises the following steps: mixing ethyl acetate, a surfactant, sodium tetraphenylborate, trioctyl phosphate and a sodium carbonate solution; stirring at normal temperature and normal pressure to realize homogeneous emulsification of the solution of ethyl acetate, surfactant, sodium tetraphenylborate, trioctyl phosphate and sodium carbonate, so as to obtain a liquid film.
2. 2. The method for obtaining concentrated lithium from gas field produced water according to claim 1, wherein the volume ratio of the produced water after oxidative degradation to the liquid film is 0.1-5.
3. 3. The method for obtaining concentrated lithium from gas field produced water according to claim 2, wherein the volume ratio of ethyl acetate to trioctyl phosphate is 1-5, the volume ratio of trioctyl phosphate to sodium tetraphenylborate is 1-10, the volume ratio of organic solvent to sodium carbonate solution is 2-20, and the mass fraction ratio of ethyl acetate to surfactant is 10-100; wherein the organic solvent comprises ethyl acetate, trioctyl phosphate, sodium tetraphenylborate and a surfactant.
4. 4. A method of obtaining concentrated lithium from gas field produced water according to claim 3, wherein the surfactant has an HLB value of 3 to 6.
5. 5. A system for obtaining concentrated lithium from gas field produced water for implementing the method according to any one of claims 1-4, characterized by comprising an oxidation mechanism (10), a liquid film mechanism (20) and a concentration mechanism (30) connected in sequence; the oxidation mechanism (10) is used for carrying out oxidative degradation on produced water; the liquid film mechanism (20) is used for selectively extracting lithium from the produced water after oxidative degradation; The concentration mechanism (30) is used for concentrating lithium in the produced water after the selective extraction.
6. 6. A system for obtaining concentrated lithium from gas field produced water according to claim 5, wherein the oxidation mechanism (10) comprises an oxidation reaction tank (11).
7. 7. A system for obtaining concentrated lithium from gas field produced water according to claim 5, wherein said liquid film mechanism (20) comprises a stirred tank separator (21) and a demulsification tank (22), said oxidation mechanism (10) is connected to said stirred tank separator (21), and said stirred tank separator (21) is connected to said demulsification tank (22).
8. 8. A system for obtaining concentrated lithium from gas field produced water according to claim 7, wherein said liquid film mechanism (20) further comprises a liquid film preparation device (23), said liquid film preparation device (23) being connected to said agitation separator tank (21).
9. 9. The system for obtaining concentrated lithium from gas field produced water according to claim 7, wherein the concentration mechanism (30) comprises a membrane distillation reactor (31), a condensation collection tank (32) and a concentrated lithium liquid storage tank (33), the demulsification tank (22) is connected with the membrane distillation reactor (31), and the membrane distillation reactor (31) is respectively connected with the condensation collection tank (32) and the concentrated lithium liquid storage tank (33).

Description

System and method for obtaining concentrated lithium from gas field produced water Technical Field The invention belongs to the field of treatment of gas field produced water, and particularly relates to a system and a method for obtaining concentrated lithium from gas field produced water. Background Along with the continuous promotion of the strategic targets of 'stable oil and gas increase' in China, the crude oil yield steadily rises, the natural gas yield accelerates the up-production, the water yield of oil and gas field produced water in the development process of the oil and gas field is obviously increased, the total amount of the oil and gas field produced water in the current stage is approximately 10 hundred million tons/year, and the increase of the oil and gas field produced water by 10% in 2030 is expected. The produced water of the gas field is produced by underground natural gas, the mineralization degree of the water body is high, a large amount of high-added-value components including lithium, potassium, bromine, iodine, boron and the like are enriched, the occurrence taste of partial areas can reach the mineral indexes of deep-reservoir salts, the extraction and utilization values are high, and the overall recycling potential is high along with the increase of the water quantity of the produced water of the gas field. At present, gas field produced water is treated by taking reinjection as a main treatment path and a small amount of water is discharged from a part of areas. The produced water surface treatment process corresponding to reinjection treatment mainly takes suspended solids and the like in water as removal objects, adopts technical methods such as air floatation, filtration and the like, and the produced water surface treatment objects corresponding to outward discharge treatment comprise sulfide removal, organic matters, salts and the like, and mainly adopts technical methods such as filtration, air floatation, oxidation, membrane separation and the like. In the current treatment process of gas field effluent, high added value components such as lithium in water cannot be effectively extracted and recycled. Lithium is the lightest metal element in nature, mainly exists in the form of hard rock such as spodumene, lepidolite, and gibbsite, and also exists in salt lake brine and underground deep-storage brine. Lithium is widely used in important fields such as batteries, glass, lubricating grease and the like, and with development and application of new energy automobiles and energy storage technologies, lithium is paid attention to in the field of new energy materials and becomes an important strategic resource. Under the push of the high-quality development of new energy industry in China, the consumption speed of lithium is rapidly increased. It is necessary to extract lithium from the produced water. In view of this, the present invention has been made. Disclosure of Invention In order to achieve effective extraction of lithium from gas field produced water, the invention provides a system and a method for obtaining concentrated lithium from gas field produced water. The system can realize the effective extraction and concentration of the lithium in the produced water, and improves the recovery rate of the lithium in the produced water. The invention comprises the following technical scheme: The first aspect of the invention provides a system for obtaining concentrated lithium from gas field produced water, which comprises an oxidation mechanism, a liquid film mechanism and a concentration mechanism which are connected in sequence; The oxidation mechanism is used for carrying out oxidative degradation on produced water; the liquid film mechanism is used for selectively extracting lithium from the produced water after oxidative degradation; the concentration mechanism is used for concentrating lithium in the produced water after the selective extraction. Further, the oxidation mechanism includes an oxidation reaction tank. Further, the liquid film mechanism comprises a stirring separation tank and a demulsification tank, the oxidation mechanism is connected with the stirring separation tank, and the stirring separation tank is connected with the demulsification tank. Further, the liquid film mechanism further comprises a liquid film preparation device, and the liquid film preparation device is connected with the stirring separation tank. Further, the concentration mechanism comprises a membrane distillation reactor, a condensation collection tank and a concentrated lithium liquid storage tank, wherein the demulsification tank is connected with the membrane distillation reactor, the membrane distillation reactor is respectively connected with the condensation collection tank and the concentrated lithium liquid storage tank, preferably, the upper end of the demulsification tank is connected with an emulsion liquid film preparation device, and the lower end of the demulsificati