CN110577851A - A device and method for rapid and continuous hydration separation of coalbed methane - Google Patents

Abstract

A rapid continuous hydration separation coal bed gas device and method. The device mainly includes a feed gas path, a separation liquid circulation loop, a hydration separation tower, a nitrogen-enriched gas path, a methane-enriched gas path, connecting pipes and valves. A gas cylinder, a gas decompression valve, a gas buffer tank, a pressurization system, and a first gas flowmeter are connected to the feed gas path. The method is to use nitrogen insoluble in the oil phase, but methane is easily soluble in the oil phase, using the water-in-oil emulsion as the separation liquid, increasing the contact area between the methane and water, and under the action of a uniform distributor at the upper liquid inlet of the separation tower , the separation liquid flows down along the spiral channel in the form of a flat film, and the mixed gas enters from the bottom of the tower, and contacts the separation liquid countercurrently along the spiral channel, rapidly forming hydrates and flowing to the bottom of the tower in the form of hydrate slurry. The invention has the advantages of increasing the gas-liquid contact area, thereby enhancing mass transfer and rapidly generating hydrate, and adopting the water-in-oil emulsion to ensure the fluidity of the hydrate slurry and improve the separation selectivity.

Description

A device and method for rapid and continuous hydration separation of coalbed methane

technical field

The invention relates to the field of separation and purification of mixed gas, in particular to a rapid continuous hydration separation coal bed gas device and method.

technical background

Coal bed methane, also known as coal bed methane (CBM), is widely produced and stored in coal seams. China has abundant coalbed methane resources within a depth of 2000 m underground, with a total volume of 31×10 ¹² m ³ . Coal mining in China mainly adopts underground extraction, and the pressure of the extracted coalbed methane is low. The volume fraction of CH ₄ in two-thirds of the coalbed methane is less than 30%, and it is mixed with air. Most of it is directly discharged into the atmosphere. It reaches 1.9×10 ¹⁰ m ³ per year, equivalent to 2.0×10 ⁸ t standard coal, which not only causes energy waste, but also pollutes the environment and damages the climate.

At present, the main methods for separating mixed gas are: cryogenic method, pressure swing adsorption method, and membrane separation method. These three methods are widely used in industry and the technology is mature, but there are some inherent limitations. The cryogenic separation method requires cascade refrigeration to achieve low temperature conditions, which requires high energy consumption, and the cyclic refrigeration process is also relatively complicated. The equipment investment is large, the requirements for the impurity content in the raw materials are relatively strict, and the product purity is generally low. The pressure swing adsorption technology uses a lot of equipment, occupies a large area, and the process and program control are complex, requiring frequent switching and large investment in equipment. The recovery rate and product purity of the membrane separation method are usually not high, and it has high requirements on the membrane material, the membrane has a short service life, high cost, and easy loss of gas, so it is only suitable for small-scale mixed gas purification devices.

Hydrate separation mixed gas method is an emerging separation technology in recent years. Using water-in-oil emulsion as the separation medium, taking advantage of the characteristics that hydrocarbons are easily soluble in the oil phase, the coalbed methane is separated twice through absorption and hydration, which can improve the separation of methane selective. Compared with traditional separation methods, the hydrate method has the advantages of small pressure loss, low cost, mild reaction conditions, simple process, safety, and easy industrial continuous production.

Although a lot of research has been done on the use of hydrates to separate various mixed gases in recent years, and great progress has been made, but they are basically intermittent operations with poor continuity and low production efficiency, making it difficult to realize industrialization.

Contents of the invention

The purpose of the present invention is to overcome the problems existing in the prior art and provide a high selectivity, low energy consumption, rapid continuous hydration separation coal bed gas device and method.

The object of the invention is achieved through the following technical solutions:

A rapid continuous hydration separation coalbed methane device, comprising a feed gas path, a separation liquid circulation loop, a hydration separation tower, a nitrogen-enriched gas path, and a methane-enriched gas path; the hydration separation tower is provided with an air inlet, a liquid inlet, a rich Nitrogen outlet, hydrate slurry outlet, coolant inlet and coolant outlet; the feed gas path includes a gas cylinder, a gas pressure reducing valve, a gas buffer tank, a booster system, a first gas flow meter, a first stop valve, The first vent valve, the second shut-off valve and the third shut-off valve; the gas cylinder, the gas decompression valve, the gas buffer tank, the pressurization system, and the first gas flow meter are connected in sequence through pipelines, and the first gas flow The gauge is connected to the inlet of the hydration separation tower through a pipeline; a first cut-off valve is arranged between the gas decompression valve and the gas buffer tank, and the top of the gas buffer tank is connected with a first vent valve through a three-way connection. A second cut-off valve is arranged between the gas buffer tank and the pressurization system, and a third cut-off valve is arranged between the first gas flow meter and the hydration separation tower; the feed gas path is connected to the inlet of the hydration separation tower through a pipeline. Gas port; the separation liquid circulation circuit includes a separation liquid storage tank, a first liquid level monitoring device, a liquid delivery pump, a liquid flow meter, a second liquid level monitoring device, a solid-liquid mixed delivery pump, a resolver, a third liquid level Monitoring device, the first solenoid valve, the second solenoid valve, the third solenoid valve, the second vent valve, the second liquid discharge port, the feeding port, the third liquid discharge port, and the fourth shut-off valve; the inlet of the hydration separation tower The liquid port is connected to the liquid flow meter and the liquid delivery pump in sequence, and the liquid delivery pump is connected to the bottom of the separation liquid storage tank; the hydrate slurry outlet of the hydration separation tower is connected to the solid-liquid mixed delivery pump, the decomposer, the separation The liquid storage tanks are connected in sequence; the first solenoid valve is located on the pipeline between the hydration separation tower and the solid-liquid mixed delivery pump, and is used to cooperate with the second liquid level monitoring device and the solid-liquid mixed delivery pump to control the hydration separation tower. bottom liquid level; the second solenoid valve is located on the pipeline between the decomposer and the separation liquid storage tank, and is used to cooperate with the third liquid level monitoring device to control the bottom liquid level in the decomposer; the third solenoid valve is located at the separation The pipeline between the liquid storage tank and the liquid delivery pump is used to cooperate with the first liquid level monitoring device and the liquid delivery pump to control the liquid level in the separation liquid storage tank; On the right end pipe, it is used to empty the residual gas in the decomposer when the operation ends; the second liquid discharge port is located on the right end pipe of the tee at the bottom of the decomposer, and is used to discharge the residual liquid in the decomposer when the operation ends; The feeding port is located on the top of the separation liquid storage tank, and is used to add separation liquid to the separation liquid storage tank; the third liquid discharge port is located on the right end pipe of the tee at the bottom of the separation liquid storage tank, and is used to discharge the separation liquid storage tank at the end of the operation. residual liquid in the tank; the fourth cut-off valve is located on the pipeline between the liquid flow meter and the liquid inlet; the first liquid level monitoring device is located on the liquid level in the separation liquid storage tank, and the third electromagnetic valve is controlled by a current signal and the switch of the liquid delivery pump; the second liquid level monitoring device is located on the liquid surface at the bottom of the hydration separation tower, and controls the switch of the first solenoid valve and the solid-liquid mixed delivery pump through the current signal; the third liquid level monitoring device is located in the resolver On the liquid surface, the switch of the second solenoid valve is controlled by the current signal;

The separation liquid circulation loop is connected to the liquid inlet of the hydration separation tower through pipelines, and the hydrate slurry generated by the hydration reaction in the separation tower is transported from the hydrate slurry outlet at the bottom to the decomposer through a solid-liquid mixed delivery pump. After the hydrate is decomposed The separation liquid flows into the separation liquid storage tank by gravity, and then is transported to the separation tower by the liquid delivery pump for recycling;

The nitrogen-enriched gas road is connected with a back pressure valve, a second gas dryer, and a third gas flowmeter, and the nitrogen-enriched gas outlet of the hydration separation tower is connected with the backpressure valve, the second gas dryer, and the third gas flowmeter in sequence. connect;

The methane-enriched gas path is connected with a one-way check valve, a first gas dryer, and a second gas flow meter, and the hydrate slurry generated in the separation tower is pumped into the decomposer through the hydrate slurry outlet, and the decomposer The top outlet is sequentially connected with the one-way check valve, the first gas dryer, and the second gas flow meter; the methane-enriched gas produced by the decomposition of hydrate in the decomposer is discharged from the top into the methane-enriched gas circuit, and then is discharged from the methane-enriched gas circuit. The gas is discharged from the exhaust port.

Further, the buffer tank is provided with a cooling jacket to pre-cool the feed gas, thereby improving the stability of the hydration reaction conditions in the hydrate separation tower, and the buffer tank is connected with a thermometer and a pressure gauge to control the The gas and pressure of the raw material are monitored, and the top of the buffer tank is connected with a first vent valve, which can withstand a pressure of 20 MPa.

Further, the temperature and pressure conditions in the hydrate separation tower are monitored by a temperature and pressure monitoring system, and the hydrate separation tower is also provided with a vent valve, a liquid outlet and a viewing window.

Further, the hydration separation tower is a cylindrical tower reactor with a height-to-diameter ratio of 4-8:1, which can withstand a pressure of 15 MPa. The interior is a spiral channel structure, and the channel is seamlessly welded to the pillars and the inner wall of the separation tower. Coated with a hydrophobic nano-coating, the water-in-oil emulsion can flow down in the form of a flat film on the top, and the hydrate will not adhere to the channel, and it is connected with a temperature and pressure monitoring system, a cooling jacket of the separation tower and internal pillars Zhongtong has a cooling liquid to control the temperature inside the hydration tower to 273~276 K, and the tower is also equipped with a vent valve, a liquid outlet and a viewing window.

Further, the spiral channel at the position of the liquid inlet is provided with a box-type distributor, the liquid inlet nozzle is wrapped in it, the edge interfaces of the distributor are all seamlessly welded, and the upstream baffle of the distributor is a solid stainless steel plate , the downstream baffle is a stainless steel plate with many grid-like small channels on the lower edge, the grid hole width is 1 mm~5 mm, and the height is 1~3 mm, which is used to evenly distribute the separation liquid.

Further, the separation liquid circulation circuit is connected with a first liquid level monitoring device, a second liquid level monitoring device, and a third liquid level monitoring device, and the liquid level monitoring device controls the solenoid valve and the liquid delivery pump/solid-liquid mixed delivery The switch of the pump, once the liquid level is detected to be lower than the set value, the liquid level control system will send a current signal to the solenoid valve and the delivery pump, the solenoid valve and the pump will be closed, and the solenoid valve and the delivery pump will be turned on when the liquid level recovers , which plays a role in maintaining the stability and safe operation of the system.

Further, the position of the decomposer is higher than the separation liquid storage tank, so that the separation liquid at the bottom of the decomposer flows into the separation liquid storage tank under the action of gravity. The decomposer is a hydrate decomposition reactor with a heating jacket, connected with a thermometer to monitor the internal temperature, and can withstand a pressure of 15 MPa. After the hydrate slurry is decomposed in it, the gas is discharged from the top one-way check valve, and the separation The liquid flows into the separation liquid storage tank from the solenoid valve at the bottom, and is equipped with a third liquid level monitoring device, a vent valve and a liquid discharge port. The separation liquid storage tank has a cooling jacket, which can pre-cool the separation liquid, improve the stability of the hydration reaction conditions in the separation tower, and is connected with a thermometer, a first liquid level monitoring device, and has a feeding port and a liquid discharge mouth.

Further, it can be continuously fed and discharged, and the separated liquid is recycled. The flow of the separated liquid is detected and recorded by the liquid flow meter, and the flow of the raw material gas is detected and recorded by the first gas flow meter. The nitrogen-enriched gas and the methane-enriched gas are respectively After being dehydrated by the second gas dryer and the first gas dryer, the gas production is obtained through detection, recording and calculation by the third gas flowmeter and the second gas flowmeter arranged on the pipeline. A back pressure valve is also connected to the nitrogen-enriched gas path to maintain the gas pressure condition in the separation tower.

A rapid and continuous hydration separation method for coalbed methane, using the characteristics that nitrogen is difficult to dissolve in the oil phase and methane is easily soluble in the oil phase, the water-in-oil emulsion is used as the separation liquid, so that the methane is dissolved in the oil phase, and then distributed in the oil phase The small water droplets in the phase are contacted and dissolved, increasing the contact area between methane and water, thereby improving the separation selectivity and the mass transfer rate of the hydration reaction. Flowing down like a film, the mixed gas of 6-14 MPa enters from the bottom of the tower, contacts with the separation liquid countercurrently along the spiral channel, quickly generates hydrates and flows to the bottom of the tower in the form of hydrate slurry.

A method for rapid continuous hydration separation of coalbed methane, comprising the steps of:

(1) Vacuuming: Use a vacuum pump to vacuumize the gas buffer tank, hydration separation tower and decomposer to achieve the required vacuum degree;

(2) Feeding: Open the gas cylinder, the pressure reducing valve and the stop valve feed the raw material gas into the gas buffer tank to 1~5MPa, then turn on the refrigeration system, and realize the precooling of the raw material gas to 273 through the cooling jacket outside the gas buffer tank ~276K; Open the feeding port on the separation liquid storage tank, and fill the separation liquid storage tank with separation liquid;

(3) Realize separation liquid circulation: open the first liquid level monitoring device, the second liquid level monitoring device, the third liquid level monitoring device, set the liquid level parameters, and then the first liquid level monitoring device controls the solenoid valve and the liquid delivery pump to open , open the stop valve to feed liquid from the liquid inlet to the hydration separation tower, adjust the liquid inlet flow rate, observe through the window, make it flow down the spiral channel in the separation tower in the form of a liquid film, and wait for the liquid level at the bottom of the tower to reach the second liquid level monitoring device When the set value of the third liquid level monitoring device is reached, the solenoid valve and the solid-liquid mixed delivery pump are opened to deliver the liquid to the decomposer. When the liquid level in the decomposer reaches the set value of the third liquid level monitoring device, the solenoid valve is opened and the separated liquid flows downward. Return to the separation liquid storage tank, then turn on the refrigeration system of the separation liquid storage tank, and turn on the heating system on the decomposer, and realize the precooling of the separation liquid to 273~276K through the cooling jacket outside the separation liquid storage tank;

(4) Separation: Turn on the refrigeration system of the hydration separation tower, the temperature and pressure monitoring system, set the back pressure value of the back pressure valve, and then open the stop valve, the pressurization system and the stop valve will enter the hydration separation tower from the air inlet, Make it countercurrently contact with the separation liquid along the spiral channel, keep the temperature in the tower at 273-276 K, and keep the absolute pressure at 6-14 MPa. The easily hydratable component methane in the mixed gas reacts with the separation liquid to quickly form hydrates. It flows to the bottom of the tower in the form of slurry, and the nitrogen gas of the unhydrated component rises to the top of the tower, and the back pressure valve is opened to make the nitrogen-rich gas from the nitrogen-rich gas outlet dry through the second gas dryer and be discharged after being recorded by the third gas flow meter; The slurry is transported from the outlet of the hydrate slurry at the bottom of the tower to the decomposer by a solid-liquid mixed pump to decompose and release methane-rich gas. After passing through the one-way check valve, the first gas dryer is dried and recorded by the second gas flow meter before being discharged. The separation liquid after hydrate decomposition at the bottom of the decomposer flows down to the separation liquid storage tank for recycling.

In the above method, the separating liquid is a water-in-oil emulsion, which selectively dissolves the methane in the mixed gas, and increases the contact area between the methane gas and water, and the water phase in the emulsion forms a liquid phase of 2-10 μm in the oil phase. It exists in the form of droplets, the water content of the emulsion is 30 vol%~80 vol%, and the oil phase is a kind of long-chain alkanes such as hexane, heptane, octane, nonane, decane, diesel oil, gasoline, crude oil, white oil, etc. or a mixture thereof; the emulsifier is a single emulsifier or a composite emulsifier with an HLB value between 3 and 10, and the emulsifier includes a composite emulsifier of the Span class or the Span class and the Tween class, and other lipophilic surfactants or Composite system of lipophilic surfactant and hydrophilic surfactant.

In the above method, the hydrate slurry is a solid-liquid mixture in which the oil phase wraps fine hydrate particles, and the hydrate particle size is 3-20 μm. Under the action of the emulsifier on the interface between the oil phase and the hydrate particles, the It prevents the aggregation of hydrate particles and further agglomeration and blockage of pipelines, which are not conducive to continuous operation, and greatly improves the fluidity of hydrate slurry.

Compared with the prior art, the present invention has the following advantages:

The invention uses the water-in-oil emulsion to hydrate and separate the coal bed gas, so that methane gas and nitrogen gas can be separated. Because nitrogen is difficult to dissolve in the oil phase, methane is easily soluble in the oil phase, so that the methane dissolves in the oil phase and increases the contact area between methane and water. In addition, the coalbed methane is in countercurrent contact with the separation liquid flowing down in a thin film during the ascending process in the spiral channel in the separation tower. Due to the large contact area and the fluidity of the material, the mass transfer is accelerated and the heat of hydration reaction is also removed faster. . This method can greatly improve the separation selectivity and the mass transfer rate of the hydration reaction, accelerate the formation of hydrates, and improve the separation efficiency.

Compared with the separation technologies such as cryogenic method, adsorption method and membrane separation method currently used in industry, the present invention has the advantages of good separation effect, low energy consumption, reusable separation liquid, friendly environment, simple process and the like.

Compared with the currently used intermittent hydration separation method, the present invention realizes continuous separation operation, can greatly increase the space velocity of the hydration separation reactor, improves production efficiency, and has broad industrial application prospects.

Description of drawings

Fig. 1 is a schematic diagram of a rapid continuous hydration separation coalbed methane device provided by the present invention.

Fig. 2 is a schematic diagram of the structure of the uniform distributor at the inlet of the hydration separation tower.

Fig. 3 is a schematic diagram of the spiral channel structure in the hydration separation tower.

The components in the figure are as follows: gas cylinder 1, pressure reducing valve 2, gas buffer tank 4, pressure gauge 6, pressurization system 9, first gas flow meter 10, air inlet 12, hydrate slurry outlet 14, second liquid Level monitoring device 15, solid-liquid mixed transport pump 17, decomposer 18, one-way check valve 21, first gas dryer 22, second gas flow meter 23, methane-enriched gas outlet 24, third liquid level monitoring device 25. Feeding port 28, separation liquid storage tank 30, first liquid level monitoring device 31, liquid delivery pump 32, liquid flow meter 35, liquid inlet 37, hydration separation tower 38, temperature and pressure monitoring system 39, window 40, rich Nitrogen gas outlet 41, back pressure valve 43, second gas dryer 44, third gas flowmeter 45, nitrogen-enriched gas outlet 46, coolant inlet 47, coolant outlet 48, spiral channel 49, uniform distributor upstream baffle 50 , Distributor downstream baffle 51, tower inner hollow pillar 52, separation tower cooling jacket 53, first stop valve 3, second stop valve 8, third stop valve 11, fourth stop valve 36, first solenoid valve 16. The second solenoid valve 26, the third solenoid valve 33, the first vent valve 7, the second vent valve 20, the third vent valve 42, the first liquid discharge port 13, the second liquid discharge port 27, the third liquid discharge port Port 34, the first thermometer 5, the second thermometer 19, and the third thermometer 29.

Detailed ways

The content of the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figures 1 to 3, a rapid continuous hydration separation coalbed methane device includes a feed gas path, a separation liquid circulation loop, a hydration separation tower 38, a nitrogen-rich gas path and a methane-rich gas path; the hydration separation tower 38 There are air inlet 12, liquid inlet 37, nitrogen-enriched gas outlet 41, hydrate slurry outlet 14, cooling liquid inlet 47 and cooling liquid outlet 48; the feed gas path includes gas cylinder 1, gas pressure reducing valve 2, Gas buffer tank 4, pressurization system 9, first gas flow meter 10, first shut-off valve 3, first vent valve 7, second shut-off valve 8 and third shut-off valve 11; the gas cylinder 1, gas decompression Valve 2, gas buffer tank 4, pressurization system 9, first gas flow meter 10 are connected in sequence by pipeline, and described first gas flow meter 10 is connected with the air inlet 12 of hydration separation tower 38 by pipeline; A first cut-off valve 3 is arranged between the decompression valve 2 and the gas buffer tank 4, the top of the gas buffer tank 4 is connected with a first vent valve 7 through a tee, and the gas buffer tank 4 and the pressurization system 9 are connected to each other. A second shut-off valve 8 is provided, and a third shut-off valve 11 is arranged between the first gas flow meter 10 and the hydration separation tower 38; the feed gas path is connected to the gas inlet 12 of the hydration separation tower 38 through a pipeline; The separation liquid circulation loop includes a separation liquid storage tank 30, a first liquid level monitoring device 31, a liquid delivery pump 32, a liquid flow meter 35, a second liquid level monitoring device 15, a solid-liquid mixed delivery pump 17, a resolver 18, The third liquid level monitoring device 25, the first solenoid valve 16, the second solenoid valve 26, the third solenoid valve 33, the second vent valve 20, the second liquid discharge port 27, the feeding port 28, the third liquid discharge port 34, The fourth stop valve 36; the liquid inlet 37 of the hydration separation tower 38 is connected with the liquid flow meter 35 and the liquid delivery pump 32 in sequence, and the liquid delivery pump 32 is connected with the bottom end of the separation liquid storage tank 30; The hydrate slurry outlet 14 of the hydration separation tower 38 is connected to the solid-liquid mixed delivery pump 17, the decomposer 18, and the separated liquid storage tank 30 in sequence; the first electromagnetic valve 16 is located between the hydration separation tower 38 and the solid-liquid mixed delivery pump 17 On the pipeline between them, it is used to cooperate with the second liquid level monitoring device 15 and the solid-liquid mixed delivery pump 17 to control the liquid level at the bottom of the hydration separation tower 38; 30, used to cooperate with the third liquid level monitoring device 25 to control the liquid level at the bottom of the cracker 18; the third solenoid valve 33 is located on the pipeline between the separation liquid storage tank 30 and the liquid delivery pump 32 , used to cooperate with the first liquid level monitoring device 31 and the liquid delivery pump 32 to control the liquid level in the separation liquid storage tank 30; the second vent valve 20 is located on the right end pipe of the tee at the top of the decomposer 18 for operation At the end, empty the residual gas in the cracker 18; the second liquid discharge port 27 is located on the right end pipe of the tee at the bottom of the cracker 18, and is used to discharge the residual liquid in the cracker 18 when the operation ends; the charging port 28 Located at the top of the separation liquid storage tank 30, it is used to add the separation liquid to the separation liquid storage tank 30; On the end pipeline, it is used to discharge the residual liquid in the separation liquid storage tank 30 when the operation ends; the fourth shut-off valve 36 is located on the pipeline between the liquid flow meter 35 and the liquid inlet 37; the first liquid level monitoring device 31 Located on the liquid surface in the separation liquid storage tank 30, the switch of the third solenoid valve 33 and the liquid delivery pump 32 is controlled by the current signal; the second liquid level monitoring device 15 is located on the liquid surface at the bottom of the hydration separation tower 38, and is controlled by the current signal The switch of the first solenoid valve 16 and the solid-liquid mixed delivery pump 17; the third liquid level monitoring device 25 is located on the liquid surface in the resolver 18, and the switch of the second solenoid valve 26 is controlled by a current signal; the separation liquid circulation circuit passes through the pipeline Connected to the liquid inlet 37 of the hydration separation tower 38, the hydrate slurry generated by the hydration reaction in the separation tower 38 is transported from the hydrate slurry outlet 14 at the bottom to the decomposer 18 through the solid-liquid mixing pump 17, and the hydrate is decomposed and separated The liquid flows into the separation liquid storage tank 30 by gravity, and then is transported to the separation tower 38 by the liquid delivery pump 32 for recycling; Meter 45, the nitrogen-enriched gas outlet 41 of the hydration separation tower 38 is connected with the back pressure valve 43, the second gas dryer 44, and the third gas flow meter 45 in sequence; 21. The first gas dryer 22, the second gas flow meter 23, the hydrate slurry generated in the separation tower 38 is pumped into the cracker 18 through the hydrate slurry outlet 14, and the top outlet of the cracker 18 is connected to the one-way stop. The return valve 21, the first gas dryer 22, and the second gas flow meter 23 are connected in sequence; the methane-enriched gas produced by the decomposition of hydrate in the cracker 18 is discharged from the top into the methane-enriched gas circuit, and then discharged from the methane-enriched gas Outlet 24 discharges. The buffer tank 4 is equipped with a cooling jacket to pre-cool the feed gas, thereby improving the stability of the hydration reaction conditions in the hydrate separation tower 38. The buffer tank 4 is connected with a thermometer 5 and a pressure gauge 6. The raw material gas pressure in 4 is monitored, and the first vent valve 7 is also connected to the top of the buffer tank, which can withstand a pressure of 20 MPa. The temperature and pressure conditions in the hydrate separation tower 38 are monitored by a temperature and pressure monitoring system 39 , and the hydrate separation tower 38 is also provided with a vent valve 42 , a liquid discharge port 13 and a window 40 . The hydration separation tower 38 is a cylindrical tower reactor with a height-to-diameter ratio of 4 to 8:1, which can withstand a pressure of 15 MPa. The interior is a spiral channel structure, and the channel 49 is seamlessly welded with the pillar 52 and the inner wall of the separation tower. It is coated with a hydrophobic nano-coating, which allows the water-in-oil emulsion to flow down in the form of a flat film, while the hydrate will not adhere to the channel, and is connected with a temperature and pressure monitoring system 39, and a cooling jacket for the separation tower 53 And in the internal pillar 52, there is a coolant to control the temperature in the hydration tower to be 273 ~ 276 K, and the tower is also provided with a vent valve 42, a liquid outlet 13 and a window 40. The spiral channel 49 at the position of the liquid inlet 37 is provided with a box-type uniform distributor, and the liquid inlet nozzle is wrapped in it. The edge interfaces of the distributor are seamlessly welded, and the upstream baffle plate 50 of the distributor is a solid stainless steel plate , the downstream baffle plate 51 is a stainless steel plate with many grid-shaped small channels on the lower edge, the grid hole width is 1 mm to 5 mm, and the height is 1 to 3 mm, which is used to evenly distribute the separation liquid. The separation liquid circulation circuit is connected with a first liquid level monitoring device 31, a second liquid level monitoring device 15, and a third liquid level monitoring device 25, and the electromagnetic valves 33, 16, 26 and the liquid delivery pump are controlled by the liquid level monitoring device 32/The switch of the solid-liquid mixed delivery pump 17, once the liquid level is detected to be lower than the set value, the liquid level control system will send a current signal to the solenoid valve and the delivery pump, the solenoid valve and the pump will be closed, and when the liquid level recovers, it will turn on again. The solenoid valve and delivery pump will be turned on, which plays a role in maintaining the stable and safe operation of the system. The position of the decomposer 18 is higher than the separation liquid storage tank 30 , so that the separation liquid at the bottom of the decomposer flows into the separation liquid storage tank 30 under the action of gravity. The decomposer 18 is a hydrate decomposition reactor with a heating jacket, connected with a thermometer 19 to monitor the internal temperature, and can withstand a pressure of 15 MPa. After the hydrate slurry is decomposed in it, the gas is discharged from the top one-way check valve 21 , the separation liquid flows into the separation liquid storage tank 30 from the bottom electromagnetic valve 26, and is provided with a third liquid level monitoring device 25, a vent valve 20 and a liquid discharge port 27. The separation liquid storage tank 30 has a cooling jacket, which can pre-cool the separation liquid, improve the stability of the hydration reaction conditions in the separation tower 38, and is connected with a thermometer 29, a first liquid level monitoring device 31, and a feeding port 28 and drain port 34. It can continuously feed and discharge materials, and the separation liquid can be recycled. The flow rate of the separation liquid is detected and recorded by the liquid flow meter 35, and the flow rate of the raw material gas is detected and recorded by the first gas flow meter 10. The nitrogen-enriched gas and the methane-enriched gas pass through the After the second gas dryer 44 and the first gas dryer 22 are dehydrated, the gas production is obtained through the detection, recording and calculation of the third gas flowmeter 45 and the second gas flowmeter 23 arranged on the pipeline. A back pressure valve 43 is also connected to the nitrogen-enriched gas path to maintain the gas pressure condition in the separation tower 38 .

A rapid and continuous hydration separation method for coalbed methane, using the characteristics that nitrogen is difficult to dissolve in the oil phase and methane is easily soluble in the oil phase, the water-in-oil emulsion is used as the separation liquid, so that the methane is dissolved in the oil phase, and then distributed in the oil phase The small water droplets in the phase contact and dissolve, increasing the contact area between methane and water, thereby improving the separation selectivity and the mass transfer rate of the hydration reaction. 49 flows down in a flat film shape, and the mixed gas of 6-14 MPa is introduced from the bottom of the tower, and contacts with the separation liquid countercurrently along the spiral channel 49, rapidly forming hydrates and flowing to the bottom of the tower in the form of hydrate slurry.

The use process of the present invention is as follows:

(1) Vacuuming: Use a vacuum pump to evacuate the gas buffer tank 4, the hydration separation tower 38 and the decomposer 18 to achieve the required vacuum degree.

(2) Feeding: Open the gas cylinder 1, the pressure reducing valve 2 and the stop valve 3 to feed the raw material gas into the gas buffer tank 4 to 1~5MPa, then turn on the refrigeration system, and realize the raw material through the cooling jacket outside the gas buffer tank 4 The air is pre-cooled to the required temperature of 273~276K; the feeding port 28 on the separation liquid storage tank 30 is opened, and the separation liquid storage tank 30 is filled with separation liquid.

(3) Realize the separation liquid circulation: open the first liquid level monitoring device 31, the second liquid level monitoring device 15, and the third liquid level monitoring device 25, and set the liquid level parameters. Then the first liquid level monitoring device 31 controls the solenoid valve 33 and the liquid delivery pump 32 to open, opens the shut-off valve 36 to feed the liquid into the hydration separation tower 38 from the liquid inlet 37, adjusts the liquid inlet flow rate, and observes through the window 40 to make it separate smoothly. The spiral channel 49 in the tower 38 flows down in the form of a liquid film. When the liquid level at the bottom of the tower reaches the set value of the second liquid level monitoring device 15, the solenoid valve 16 and the solid-liquid mixed delivery pump 17 are opened to deliver the material liquid to the decomposer 18, and when the liquid level in the decomposer 18 reaches the third liquid When the set value of the position monitoring device 25 is reached, the electromagnetic valve 26 is opened, and the separation liquid flows back to the separation liquid storage tank 30 downward. Then the refrigeration system of the separation liquid storage tank 30 is turned on, and the heating system on the decomposer 18 is turned on, and the separation liquid is precooled to 273-276K through the cooling jacket outside the separation liquid storage tank 30 .

(4) Separation: Turn on the refrigeration system of the hydration separation tower 38, the temperature and pressure monitoring system 39, and set the back pressure value of the back pressure valve 43. Then, the shut-off valve 8 is opened, and the pressurization system 9 and the shut-off valve 11 are fed into the hydration separation tower 38 from the air inlet 12, making it contact with the separation liquid countercurrently along the spiral channel 49, and the temperature in the tower is maintained at 273 ~ 276 K, the absolute pressure is kept at 6~14 MPa. The easily hydratable component (methane) in the mixed gas contacts with the separation liquid (water-in-oil emulsion) to quickly generate hydrate, which flows to the bottom of the tower in the form of slurry, and the unhydrated component (nitrogen) rises to the top of the tower. Open the back pressure valve 43 so that the nitrogen-rich gas is discharged from the nitrogen-rich gas outlet 41 through the second gas dryer 44 and is recorded by the third gas flow meter 45; The pump 17 sends it to the cracker 18 to decompose and release methane-enriched gas, which passes through the one-way check valve 21 , is dried by the first gas dryer 22 and is discharged after being recorded by the second gas flow meter 23 . The separation liquid after decomposition of the hydrate at the bottom of the decomposer 18 flows down to the separation liquid storage tank 30 for recycling.

Claims (10)

1. A rapid and continuous hydration separation coalbed methane device, characterized in that it includes a feed gas path, a separation liquid circulation loop, a hydration separation tower (38), a nitrogen-enriched gas path and a methane-enriched gas path; The hydration separation tower (38) has an air inlet (12), a liquid inlet (37), a nitrogen-enriched gas outlet (41), a hydrate slurry outlet (14), a cooling liquid inlet (47) and a cooling liquid outlet ( 48) The feed gas path includes a gas cylinder (1), a gas pressure reducing valve (2), a gas buffer tank (4), a pressurization system (9), a first gas flow meter (10), a first stop valve (3 ), the first vent valve (7), the second shut-off valve (8) and the third shut-off valve (11); the gas cylinder (1), gas pressure reducing valve (2), gas buffer tank (4), booster The pressure system (9), the first gas flowmeter (10) are connected in sequence through pipelines, and the first gas flowmeter (10) is connected with the air inlet (12) of the hydration separation tower (38) through pipelines; A first cut-off valve (3) is set between the gas decompression valve (2) and the gas buffer tank (4), and the top of the gas buffer tank (4) is connected with a first vent valve (7) through a tee. A second shut-off valve (8) is set between the gas buffer tank (4) and the pressurization system (9), and a third shut-off valve is set between the first gas flow meter (10) and the hydration separation tower (38) (11); the feed gas path is connected to the air inlet (12) of the hydration separation tower (38) through a pipeline; The separation liquid circulation circuit includes a separation liquid storage tank (30), a first liquid level monitoring device (31), a liquid delivery pump (32), a liquid flow meter (35), a second liquid level monitoring device (15), a solid Liquid mixing pump (17), resolver (18), third liquid level monitoring device (25), first solenoid valve (16), second solenoid valve (26), third solenoid valve (33), second Vent valve (20), second liquid discharge port (27), feed port (28), third liquid discharge port (34), fourth stop valve (36); liquid inlet of the hydration separation tower (38) (37) is sequentially connected to the liquid flow meter (35) and the liquid delivery pump (32), the liquid delivery pump (32) is connected to the bottom of the separation liquid storage tank (30); the hydration separation tower (38) The hydrate slurry outlet (14) is connected to the solid-liquid mixed delivery pump (17), decomposer (18), and separation liquid storage tank (30) in sequence; the first electromagnetic valve (16) is located in the hydration separation tower (38 ) and the solid-liquid mixed delivery pump (17), used to control the liquid level at the bottom of the hydration separation tower (38) in cooperation with the second liquid level monitoring device (15) and the solid-liquid mixed delivery pump (17); The second solenoid valve (26) is located on the pipeline between the resolver (18) and the separation liquid storage tank (30), and is used to control the inner bottom of the resolver (18) in cooperation with the third liquid level monitoring device (25) liquid level; the third solenoid valve (33) is located on the pipeline between the separation liquid storage tank (30) and the liquid delivery pump (32), and is used to communicate with the first liquid level monitoring device (31) and the liquid delivery pump ( 32) Coordinated control of the liquid level in the separation liquid storage tank (30); the second vent valve (20) is located on the right end pipe of the tee at the top of the decomposer (18), and is used to vent the decomposer (18) at the end of the operation the residual gas in the cracker; the second liquid discharge port (27) is located on the right end pipe of the tee at the bottom of the cracker (18), and is used to discharge the residual liquid in the cracker (18) at the end of the operation; the feed port ( 28) Located on the top of the separation liquid storage tank (30), used to add separation liquid to the separation liquid storage tank (30); the third drain port (34) is located at the right end of the tee at the bottom of the separation liquid storage tank (30) On the pipeline, it is used to discharge the residual liquid in the separation liquid storage tank (30) at the end of the operation; the fourth shut-off valve (36) is located on the pipeline between the liquid flow meter (35) and the liquid inlet (37); The first liquid level monitoring device (31) is located on the liquid surface in the separation liquid storage tank (30), and controls the switch of the third solenoid valve (33) and the liquid delivery pump (32) through the current signal; the second liquid level monitoring device ( 15) Located on the liquid surface at the bottom of the hydration separation tower (38), the switches of the first solenoid valve (16) and the solid-liquid mixed delivery pump (17) are controlled by current signals; the third liquid level monitoring device (25) is located in the resolver (18) On the inner liquid surface, the switch of the second solenoid valve (26) is controlled by the current signal; The nitrogen-enriched gas path is connected with a back pressure valve (43), a second gas dryer (44), and a third gas flow meter (45). The nitrogen-enriched gas outlet (41) of the hydration separation tower (38) is connected to the The valve (43), the second gas dryer (44), and the third gas flow meter (45) are connected in sequence; The top outlet of the decomposer (18) is sequentially connected with a one-way check valve (21), a first gas dryer (22), and a second gas flow meter (23). 2. A rapid continuous hydration separation coalbed methane device according to claim 1, characterized in that the buffer tank (4) has a cooling jacket, and a thermometer (5) is connected to the buffer tank (4) , pressure gauge (6), and a first vent valve (7) connected to the top of the buffer tank. 3. A rapid and continuous hydration separation coalbed methane device according to claim 1, characterized in that the temperature and pressure conditions in the hydrate separation tower (38) are monitored by a temperature and pressure monitoring system (39), and the hydrate The separation tower (38) is also provided with a vent valve (42), a drain port (13) and a viewing window (40). 4. A rapid continuous hydration separation coalbed methane device according to claim 1, characterized in that, the hydration separation tower (38) is a cylindrical tower reactor with a height-to-diameter ratio of 4-8:1. It is a spiral channel structure, the channel (49) is seamlessly welded with the pillar (52) and the inner wall of the separation tower, and the channel is coated with a hydrophobic nano-coating. 5. A rapid and continuous hydration separation coalbed methane device according to claim 1, characterized in that, the spiral channel (49) at the position of the liquid inlet (37) is provided with a box-type uniform distributor, and the liquid inlet pipe The mouth is wrapped in it, and the edge joints of the spreader are all seamlessly welded. The upstream baffle (50) of the spreader is a solid stainless steel plate, and the downstream baffle (51) is a stainless steel plate with many grid-shaped small channels on the lower edge. The grid hole width is 1 mm~5 mm, and the height is 1~3 mm. 6. A rapid continuous hydration separation coalbed methane device according to claim 1, characterized in that, the position of the decomposer (18) is higher than that of the separation liquid storage tank (30), and the decomposer (18) It is a hydrate decomposition reactor with a heating jacket, connected with a thermometer (19); the separation liquid storage tank (30) has a cooling jacket. 7. A rapid and continuous hydration separation method for coalbed methane, characterized in that, utilizing the characteristics that nitrogen is hardly soluble in the oil phase and methane is easily soluble in the oil phase, water-in-oil emulsion is used as the separating liquid to dissolve methane in the oil phase , and then contact and dissolve the small water droplets distributed in the oil phase, increasing the contact area between methane and water, thereby improving the separation selectivity and the mass transfer rate of the hydration reaction, and the liquid inlet (37) at the upper part of the separation tower Under the action, the separation liquid flows down along the helical channel (49) in the form of a flat film, and the mixed gas of 6~14 MPa enters from the bottom of the tower, and contacts with the separation liquid countercurrently along the helical channel (49), rapidly forming hydrate and hydrate Slurry form flows to the bottom of the column. 8. A kind of rapid continuous hydration separation coalbed methane method according to claim 7, is characterized in that, comprises the steps: (1) Vacuuming: Use a vacuum pump to vacuumize the gas buffer tank (4), the hydration separation tower (38) and the decomposer (18) to achieve the required vacuum degree; (2) Feeding: Open the gas cylinder (1), the pressure reducing valve (2) and the stop valve (3) to feed the raw material gas into the gas buffer tank (4) to 1~5MPa, then turn on the refrigeration system, and pass through the gas buffer tank ( 4) The outer cooling jacket realizes the pre-cooling of the raw material gas to 273~276K; open the feeding port (28) on the separation liquid storage tank (30), and fill the separation liquid storage tank (30) with separation liquid; (3) Realize separation liquid circulation: open the first liquid level monitoring device (31), the second liquid level monitoring device (15), the third liquid level monitoring device (25), set the liquid level parameters, and then the first liquid level monitoring The device (31) controls the opening of the electromagnetic valve (33) and the liquid delivery pump (32), opens the shut-off valve (36) and feeds the liquid from the liquid inlet (37) to the hydration separation tower (38), adjusts the flow of the liquid, and passes through the window ( 40) Observe to make it flow down the spiral channel (49) in the separation tower (38) in the form of a liquid film, and when the liquid level at the bottom of the tower reaches the set value of the second liquid level monitoring device (15), the solenoid valve (16) and the solid-liquid mixed delivery pump (17) is turned on to deliver the liquid to the decomposer (18). When the liquid level in the decomposer (18) reaches the set value of the third liquid level monitoring device (25), the solenoid valve (26 ) is turned on, the separation liquid flows back to the separation liquid storage tank (30), then the refrigeration system of the separation liquid storage tank (30) is turned on, and the heating system on the decomposer (18) is turned on, and the separation liquid flows through the separation liquid storage tank (30) The cooling jacket realizes the pre-cooling of the separation liquid to 273K~276K; (4) Separation: Open the refrigeration system of the hydration separation tower (38), the temperature and pressure monitoring system (39), set the back pressure value of the back pressure valve (43), then open the stop valve (8), pressurize the system (9 ) and shut-off valve (11) from the air inlet (12) to the hydration separation tower (38), so that it contacts with the separation liquid countercurrently along the spiral channel (49), and the temperature in the tower is kept at 273 ~ 276 K, The absolute pressure is kept at 6~14 MPa, the easily hydratable component methane in the mixed gas contacts with the separation liquid to quickly generate hydrate, which flows to the bottom of the tower in the form of slurry, and the nitrogen gas of the unhydrated component rises to the top of the tower, and the back pressure valve is opened (43) The nitrogen-rich gas is discharged from the nitrogen-rich gas outlet (41) through the second gas dryer (44) and recorded by the third gas flowmeter (45); the hydrate slurry is discharged from the bottom hydrate slurry outlet (14 ) is transported to the decomposer (18) by the solid-liquid mixed pump (17) to decompose and release methane-rich gas, which passes through the one-way check valve (21), is dried by the first gas dryer (22) and is passed through the second gas flowmeter (23) After being recorded, it is discharged, and the separation liquid after hydrate decomposition at the bottom of the decomposer (18) flows down to the separation liquid storage tank (30) for recycling. 9. A kind of rapid continuous hydration method for separating coalbed methane according to claim 8, characterized in that, the separating liquid is a water-in-oil emulsion, and the water phase in the emulsion is in the oil phase with 2 ~ 10 μm droplets It exists in dispersed form, the water content of the emulsion is 30vol%~80vol%, the oil phase is hexane, heptane, octane, nonane, decane, diesel oil, gasoline, crude oil, white oil or a mixture thereof; the emulsifier is A single emulsifier or compound emulsifier with an HLB value between 3 and 10, the emulsifier includes Span or Span and Tween compound emulsifiers, and other lipophilic surfactants or lipophilic surfactants and hydrophilic surfactants Composite system of water-based surfactants. 10. A method for rapid and continuous hydration separation of coalbed methane according to claim 8, characterized in that the hydrate slurry is a solid-liquid mixture in which the oil phase wraps fine hydrate particles, and the hydrate particle size is 3 ~ 20 μm.