Shale gas exploitation wastewater forward osmosis membrane distillation coupling device

Abstract

The utility model relates to a forward osmosis membrane distillation coupling device for shale gas exploitation wastewater. According to the technical scheme, a raw material liquid tank is sequentially connected with raw material liquid inlet ends of a first-stage forward osmosis assembly, a second-stage forward osmosis assembly and a third-stage forward osmosis assembly through pipelines and a forward osmosis water pump; a liquid outlet of the circulating driving liquid tank is sequentially connected with a driving liquid inlet end through a pipeline and a driving liquid water pump; the three-stage forward osmosis assembly is connected to the raw material liquid tank for circulation through a pipeline; the drawn liquid outlet end is connected to a heater through a pipeline and a heat exchanger, the output end of the heater is connected to a high-temperature side inlet of a membrane distillation assembly through a pipeline and a membrane distillation driving pump, and a low-temperature side outlet of the membrane distillation assembly is connected to a reclaimed water storage tank through a pipeline and a condenser. Moreover, the method is realized through membrane distillation, moisture on the high-temperature side moves towards the low-temperature side, the drawn liquid is recovered while fresh water is obtained, and the treatment cost of the high-salinity oil-containing wastewater is reduced.

Description

Technical Field

[0001] The utility model relates to a shale gas wastewater treatment device, in particular to a shale gas mining wastewater forward osmosis membrane distillation coupling device. Background Art

[0002] At present, the shale gas wastewater in China is mainly discharged by centralized collection and placement, and then regularly handed over to water treatment companies for transportation and treatment. There are problems such as serious waste of water resources, high wastewater treatment costs, and high environmental pollution risks. my country's environmental protection regulations stipulate that wastewater must be harmlessly treated before discharge. If the water quality meets specific standards, the treated wastewater can be further reused, thus providing a way to reduce the burden of fresh water supply in today's increasingly scarce water resources. However, how to efficiently, economically and environmentally treat this type of high-salinity oily wastewater is an urgent problem to be solved in the current oil and gas field exploitation, especially in the shale gas exploitation process; at the same time, my country's shale gas storage areas are mostly in water-scarce areas, and wastewater reuse (for fracturing fluid or as domestic water) is crucial to the sustainable development of shale gas.

[0003] In addition, there are six main methods for treating high-salinity oily wastewater: flotation, coagulation, biological treatment, mixing technology, advanced oxidation technology and membrane separation technology. Compared with other treatment methods, membrane separation technology has great advantages, and has good application effects in desalination and removal of volatile organic compounds. It is also simple to operate and easy to maintain, so it has a good application prospect in the treatment of high-salinity oily wastewater.

[0004] Among them, forward osmosis (FO) is a membrane separation process driven by osmotic pressure, that is, water molecules spontaneously diffuse from the feed liquid side (FS) through the selective permeable membrane to the draw liquid side (DS) under the action of the osmotic pressure difference (Δπ). It does not require external pressure (Δp) like reverse osmosis (RO) and slow pressure osmosis (PRO) processes, and has the advantages of low energy consumption, high anti-pollution and operation under normal pressure. Due to the high retention of the FO membrane, most of the pollutants in the wastewater can be intercepted, which can not only realize the regeneration and reuse of water resources, but also concentrate the feed liquid concentration, facilitate the recovery of nutrients such as nitrogen, phosphorus, and iodine in the water, so as to achieve sustainable utilization of resources. According to research, the FO process has good anti-pollution ability, which can achieve 100% trace metal retention, 99% removal of COD and phosphate, and 60%-70% retention of ammonia nitrogen and total nitrogen in the wastewater to be treated; after a period of treatment, the water flux can also be restored to a high degree by physical cross-flow and chemical cleaning of the membrane surface. Utility Model Content

[0005] The purpose of the utility model is to address the above-mentioned defects in the prior art and to provide a shale gas mining wastewater forward osmosis membrane distillation coupling device, which reduces the treatment cost of high-salt oily wastewater through the coupling use of multi-stage forward osmosis and membrane distillation, and is simple to operate and easy to maintain.

[0006] The utility model discloses a shale gas mining wastewater forward osmosis membrane distillation coupling device, and its technical scheme is as follows: comprising a wastewater filter tank (1), a raw material liquid tank (2), a circulating drive liquid tank (3), a first-stage forward osmosis component (4), a second-stage forward osmosis component (5), a third-stage forward osmosis component (6), a heat exchanger (7), a heater (8), a membrane distillation component (9), a recycled water storage tank (10), a concentrated water storage tank (11), a forward osmosis water pump (12), a drive liquid water pump (13), a forward osmosis throttle valve (14), a membrane distillation drive pump ( 15), a concentrated water circulation pump (16), an infusion pump (17), and a blower (18); the liquid outlet of the raw liquid tank (2) is connected to the raw liquid inlet (4.1) of the first-stage forward osmosis component (4), the second-stage forward osmosis component (5), and the third-stage forward osmosis component (6) in sequence through a pipeline and a forward osmosis water pump (12); the liquid outlet of the circulating drive liquid tank (3) is connected to the drive liquid inlet (4.1) of the first-stage forward osmosis component (4), the second-stage forward osmosis component (5), and the third-stage forward osmosis component (6) in sequence through a pipeline and a drive liquid water pump (13). 4.2), the raw liquid outlet end (6.1) of the three-stage forward osmosis component (6) is connected to the forward osmosis throttle valve (14) through a pipeline and connected to the raw liquid tank (2) for circulation; the draw liquid outlet end (6.2) of the three-stage forward osmosis component (6) is connected to the tube side inlet of the heat exchanger (7) through a pipeline, the tube side outlet of the heat exchanger (7) is connected to the heater (8) through a pipeline, the output end of the heater (8) is connected to the high temperature side inlet of the membrane distillation component (9) through a pipeline and a membrane distillation drive pump (15), and the membrane distillation component ( The high-temperature side outlet of the heat exchanger (9) is connected to the shell-side inlet of the heat exchanger (7) through a pipeline, the low-temperature side outlet is connected to the regenerated water storage tank (10) through a pipeline and a condenser (19), and the low-temperature side inlet is connected to the blower (18) through a pipeline; the shell-side outlet of the heat exchanger (7) is connected to the concentrated water storage tank (11) through a pipeline, the output end of the concentrated water storage tank (11) is connected to the circulation drive liquid tank (3) through a pipeline and a concentrated water circulation pump (16), and the liquid outlet of the wastewater filter tank (1) is connected to the concentrated water storage tank (11) through a pipeline and an infusion pump (17).

[0007] Preferably, the heater (8) is a solar heater and a gas water heater connected in combination.

[0008] Preferably, a multi-layer filter screen (1.1) is installed in the middle of the wastewater filter tank (1).

[0009] Preferably, one of the high temperature side outlets of the membrane distillation assembly (9) is connected to the shell side inlet of the heat exchanger (7) through a pipeline and a second control valve (a2), and the other is connected to the concentrated water storage tank (11) through a pipeline and a sixth control valve (a6).

[0010] Preferably, the shell side outlet of the heat exchanger (7) is connected to the circulation drive liquid tank (3) via a pipeline and a ninth control valve (a9).

[0011] Preferably, the output end of the concentrated water circulating water pump (16) is connected to the circulating drive liquid tank (3) via a pipeline and a first control valve (a1).

[0012] Preferably, the blower (18) is a positive displacement blower.

[0013] The beneficial effects of the utility model are as follows: through the multi-stage forward osmosis components, water molecules spontaneously diffuse from the feed liquid side through the selectively permeable membrane to the draw liquid side, thereby increasing the permeation volume and reducing energy consumption; moreover, through membrane distillation, the water on the high-temperature side moves to the low-temperature side, and through the heat exchange between the forward osmosis process and the cold temperature of the membrane distillation, the latent heat is recovered and reused, and the draw liquid is recovered while obtaining fresh water; in short, on the one hand, the utility model uses the forward osmosis process as a pretreatment process, which can reduce the possibility of contamination of the membrane distillation membrane and improve the overall operating efficiency of the device; on the other hand, the membrane distillation process is used to treat the draw liquid in the forward osmosis process, which can maintain a high osmotic pressure difference between the feed liquid and the draw liquid, so that the forward osmosis process can continue to operate efficiently; the forward osmosis-membrane distillation coupling process includes two high-retention rate membrane processes, which can realize double-barrier treatment of wastewater, thereby improving the removal of pollutants such as organic matter, oil substances, surfactants, etc., which is much higher than the removal rate when the same pollutants are treated by independent forward osmosis or membrane distillation processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the flow chart of Example 1 of the utility model;

[0015] Figure 2 It is a schematic diagram of the flow chart of Example 2 of the utility model;

[0016] In the figure above: wastewater filter tank 1, raw liquid tank 2, circulating drive liquid tank 3, first-stage forward osmosis component 4, second-stage forward osmosis component 5, third-stage forward osmosis component 6, heat exchanger 7, heater 8, membrane distillation component 9, regenerated water storage tank 10, concentrated water storage tank 11, forward osmosis water pump 12, drive liquid water pump 13, forward osmosis throttle valve 14, fourth water pump 15, concentrated water circulation water pump 16, infusion pump 17, blower 18, condenser 19, filter screen 1.1, raw liquid inlet end 4.1, drive liquid inlet end 4.2, raw liquid outlet end 6.1, drawn liquid outlet end 6.2, first control valve a1, second control valve a2, third control valve a3, fourth control valve a4, fifth control valve a5, sixth control valve a6, seventh control valve a7, eighth control valve a8, ninth control valve a9. DETAILED DESCRIPTION

[0017] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0018] Example 1, reference Figure 1The utility model discloses a shale gas mining wastewater forward osmosis membrane distillation coupling device, comprising a wastewater filtration tank 1, a raw material liquid tank 2, a circulating driving liquid tank 3, a first-stage forward osmosis component 4, a second-stage forward osmosis component 5, a third-stage forward osmosis component 6, a heat exchanger 7, a heater 8, a membrane distillation component 9, a regenerated water storage tank 10, a concentrated water storage tank 11, a forward osmosis water pump 12, a driving liquid water pump 13, a forward osmosis throttle valve 14, a membrane distillation driving pump 15, a concentrated water circulating water pump 16, an infusion pump 17, and a blower 18. The liquid outlet of the raw material liquid tank 2 is connected to the raw material liquid inlet end 4.1 of the first-stage forward osmosis component 4, the second-stage forward osmosis component 5 and the third-stage forward osmosis component 6 in sequence through a pipeline and the forward osmosis water pump 12; the liquid outlet of the circulating driving liquid tank 3 is connected to the driving liquid inlet end 4.2 of the first-stage forward osmosis component 4, the second-stage forward osmosis component 5 and the third-stage forward osmosis component 6 in sequence through a pipeline and the driving liquid water pump 13. The raw liquid outlet end 6.1 of the first-stage forward osmosis component 6 is connected to the forward osmosis throttle valve 14 through a pipeline and connected to the raw liquid tank 2 for circulation; the draw liquid outlet end 6.2 of the three-stage forward osmosis component 6 is connected to the tube side inlet of the heat exchanger 7 through a pipeline, the tube side outlet of the heat exchanger 7 is connected to the heater 8 through a pipeline, the output end of the heater 8 is connected to the high temperature side inlet of the membrane distillation component 9 through a pipeline and a membrane distillation drive pump 15, the high temperature side outlet of the membrane distillation component 9 is connected to the shell side inlet of the heat exchanger 7 through a pipeline, the low temperature side outlet is connected to the regenerated water storage tank 10 through a pipeline and a condenser 19, and the low temperature side inlet is connected to a blower 18 through a pipeline; the shell side outlet of the heat exchanger 7 is connected to the concentrated water storage tank 11 through a pipeline, the output end of the concentrated water storage tank 11 is connected to the circulation drive liquid tank 3 through a pipeline and a concentrated water circulation water pump 16, and the liquid outlet of the wastewater filter pool 1 is connected to the concentrated water storage tank 11 through a pipeline and an infusion pump 17.

[0019] The heater 8 is a combination of a solar heater and a gas water heater, and the combination of the two can maintain the continuous operation of the device.

[0020] A multi-layer filter screen 1.1 is installed in the middle of the wastewater filter tank 1.

[0021] One of the high temperature side outlets of the membrane distillation assembly 9 is connected to the shell side inlet of the heat exchanger 7 through a pipeline and the second control valve a2, and the other is connected to the concentrated water storage tank 11 through a pipeline and the sixth control valve a6.

[0022] The output end of the concentrated water circulation pump 16 is connected to the circulation drive liquid tank 3 through a pipeline and a first control valve a1, and the blower 18 is a positive displacement blower.

[0023] When the utility model is used, the shale gas mining wastewater after primary treatment is sent to the wastewater filter pool 1, and then sent to the concentrated water storage tank 11 by the infusion pump 17, the water in the raw liquid tank 2 is sent to the first-stage forward osmosis component 4, the second-stage forward osmosis component 5 and the third-stage forward osmosis component 6 by the forward osmosis water pump 12, and the outlet of the circulating driving liquid tank 3 is connected to the first-stage forward osmosis component 4, the second-stage forward osmosis component 5 and the third-stage forward osmosis component 6 in sequence through the pipeline and the driving liquid water pump 13, and the water will enter the high-concentration driving liquid formed by the drawing liquid through the pipe. The line is sent to the heat exchanger 7, and the raw material liquid returns to the raw material liquid tank 2 along the forward osmosis throttle valve 14 and the pipeline to continue to be circulated; the drawn liquid is preheated through the heat exchanger 7 and sent to the heater 8, and then sent to the membrane distillation component 9 after heating. The water vapor on the high-temperature side enters the low-temperature side and is then blown out and condensed into water; the liquid on the high-temperature side is sent to the heat exchanger 7 to preheat the drawn liquid, which improves the recycling of heat. In addition, the forward osmosis component 6 used also reduces energy consumption, thereby reducing the treatment cost of shale gas extraction wastewater.

[0024] Example 2, reference Figure 1The utility model discloses a shale gas mining wastewater forward osmosis membrane distillation coupling device, comprising a wastewater filtration tank 1, a raw material liquid tank 2, a circulating driving liquid tank 3, a first-stage forward osmosis component 4, a second-stage forward osmosis component 5, a third-stage forward osmosis component 6, a heat exchanger 7, a heater 8, a membrane distillation component 9, a regenerated water storage tank 10, a concentrated water storage tank 11, a forward osmosis water pump 12, a driving liquid water pump 13, a forward osmosis throttle valve 14, a membrane distillation driving pump 15, a concentrated water circulating water pump 16, an infusion pump 17, and a blower 18. The liquid outlet of the raw material liquid tank 2 is connected to the raw material liquid inlet end 4.1 of the first-stage forward osmosis component 4, the second-stage forward osmosis component 5 and the third-stage forward osmosis component 6 in sequence through a pipeline and the forward osmosis water pump 12; the liquid outlet of the circulating driving liquid tank 3 is connected to the driving liquid inlet end 4.2 of the first-stage forward osmosis component 4, the second-stage forward osmosis component 5 and the third-stage forward osmosis component 6 in sequence through a pipeline and the driving liquid water pump 13. The raw liquid outlet end 6.1 of the first-stage forward osmosis component 6 is connected to the forward osmosis throttle valve 14 through a pipeline and connected to the raw liquid tank 2 for circulation; the draw liquid outlet end 6.2 of the three-stage forward osmosis component 6 is connected to the tube side inlet of the heat exchanger 7 through a pipeline, the tube side outlet of the heat exchanger 7 is connected to the heater 8 through a pipeline, the output end of the heater 8 is connected to the high temperature side inlet of the membrane distillation component 9 through a pipeline and a membrane distillation drive pump 15, the high temperature side outlet of the membrane distillation component 9 is connected to the shell side inlet of the heat exchanger 7 through a pipeline, the low temperature side outlet is connected to the regenerated water storage tank 10 through a pipeline and a condenser 19, and the low temperature side inlet is connected to a blower 18 through a pipeline; the shell side outlet of the heat exchanger 7 is connected to the concentrated water storage tank 11 through a pipeline, the output end of the concentrated water storage tank 11 is connected to the circulation drive liquid tank 3 through a pipeline and a concentrated water circulation water pump 16, and the liquid outlet of the wastewater filter pool 1 is connected to the concentrated water storage tank 11 through a pipeline and an infusion pump 17.

[0025] The difference from Example 1 is:

[0026] The shell side outlet of the heat exchanger 7 of the present invention is connected to the circulation drive liquid tank 3 through a pipeline and a ninth control valve a9, which can facilitate effective control of the device.

[0027] The above is only a preferred embodiment of the utility model. Any person skilled in the art may modify the utility model by using the above technical solution or modify it into an equivalent technical solution. Therefore, any simple modification or equivalent transformation based on the technical solution of the utility model shall fall within the scope of protection claimed by the utility model.

Claims

1. A shale gas mining wastewater forward osmosis membrane distillation coupling device, characterized by: It includes a wastewater filter tank (1), a raw material liquid tank (2), a circulating drive liquid tank (3), a first-stage forward osmosis component (4), a second-stage forward osmosis component (5), a third-stage forward osmosis component (6), a heat exchanger (7), a heater (8), a membrane distillation component (9), a recycled water storage tank (10), a concentrated water storage tank (11), a forward osmosis water pump (12), a drive liquid water pump (13), a forward osmosis throttle valve (14), a membrane distillation drive pump (15), a concentrated water circulating water pump (16), an infusion pump (17), and a blower (18), the liquid outlet of the raw material liquid tank (2) is connected to the raw material liquid inlet (4.1) of the first-stage forward osmosis component (4), the second-stage forward osmosis component (5) and the third-stage forward osmosis component (6) in sequence through a pipeline and a forward osmosis water pump (12); the liquid outlet of the circulating drive liquid tank (3) is connected to the drive liquid inlet (4.2) of the first-stage forward osmosis component (4), the second-stage forward osmosis component (5) and the third-stage forward osmosis component (6) in sequence through a pipeline and a drive liquid water pump (13), and the third-stage forward osmosis component (6) is connected to the raw material liquid inlet (4.1) of the first-stage forward osmosis component (4), the second-stage forward osmosis component (5) and the third-stage forward osmosis component (6) in sequence through a pipeline and a drive liquid water pump (13). The raw liquid outlet (6.1) is connected to the forward osmosis throttle valve (14) through a pipeline and connected to the raw liquid tank (2) for circulation; the draw liquid outlet (6.2) of the three-stage forward osmosis assembly (6) is connected to the tube side inlet of the heat exchanger (7) through a pipeline, the tube side outlet of the heat exchanger (7) is connected to the heater (8) through a pipeline, the output end of the heater (8) is connected to the high temperature side inlet of the membrane distillation assembly (9) through a pipeline and a membrane distillation drive pump (15), and the high temperature side outlet of the membrane distillation assembly (9) is connected to the high temperature side outlet of the membrane distillation assembly (9). The shell-side inlet of the heat exchanger (7) is connected via a pipeline, the low-temperature side outlet is connected to the regenerated water storage tank (10) via a pipeline and a condenser (19), and the low-temperature side inlet is connected to the blower (18) via a pipeline; the shell-side outlet of the heat exchanger (7) is connected to the concentrated water storage tank (11) via a pipeline, the output end of the concentrated water storage tank (11) is connected to the circulation drive liquid tank (3) via a pipeline and a concentrated water circulation pump (16), and the liquid outlet of the wastewater filter tank (1) is connected to the concentrated water storage tank (11) via a pipeline and an infusion pump (17).

2. The shale gas production wastewater forward osmosis membrane distillation coupling device according to claim 1 is characterized in that: The heater (8) is a solar heater and a gas water heater connected in combination.

3. The shale gas production wastewater forward osmosis membrane distillation coupling device according to claim 2 is characterized in that: A multi-layer filter screen (1.1) is installed in the middle of the wastewater filter tank (1).

4. The shale gas production wastewater forward osmosis membrane distillation coupling device according to claim 2 or 3, characterized in that: One of the high temperature side outlets of the membrane distillation assembly (9) is connected to the shell side inlet of the heat exchanger (7) through a pipeline and a second control valve (a2), and the other is connected to the concentrated water storage tank (11) through a pipeline and a sixth control valve (a6).

5. The shale gas production wastewater forward osmosis membrane distillation coupling device according to claim 4 is characterized in that: The shell side outlet of the heat exchanger (7) is connected to the circulation drive liquid tank (3) through a pipeline and a ninth control valve (a9).

6. The shale gas mining wastewater forward osmosis membrane distillation coupling device according to claim 5 is characterized in that: The output end of the concentrated water circulating water pump (16) is connected to the circulating drive liquid tank (3) via a pipeline and a first control valve (a1).

7. The shale gas production wastewater forward osmosis membrane distillation coupling device according to claim 1 is characterized in that: The blower (18) is a positive displacement blower.

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