Method and device for efficiently preparing carbon dioxide hydrate

Abstract

The invention discloses an efficient preparation method and device of carbon dioxide hydrate, and belongs to the technical field of preparation of carbon dioxide hydrate. Comprising the following steps: step 1, vacuumizing a reaction container to ensure that no foreign gas exists in the device; 2, graphene oxide, L-methionine, lauryl sodium sulfate and tetrahydrofuran are selected and prepared into a reaction solution; 3, adding the reaction solution into distilled water to prepare a mixed solution; 4, setting the temperature and pressure of the reaction container, determining the rotating speed of a stirring mechanism in the reaction container, and determining the duration of ultrasonic oscillation; 5, injecting the mixed solution into a reaction container by using a constant flow pump, and injecting carbon dioxide into the reaction container by using a carbon dioxide gas steel cylinder; 6, reacting until a carbon dioxide hydrate is fully generated, and taking out the carbon dioxide hydrate from the reaction container; the efficient preparation method applied to the carbon dioxide hydrate can achieve the purpose of efficiently preparing the carbon dioxide hydrate.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide hydrate preparation, and in particular to a method and device for efficiently preparing carbon dioxide hydrate. Background Art

[0002] Hydrate is a non-stoichiometric envelope crystal formed by the interaction of gas or low-boiling point liquid molecules with water molecules under low temperature and high pressure conditions. Water molecules form a cage structure through hydrogen bonds between hydrogen atoms and oxygen atoms. The guest molecules are located in the center of the cage structure and interact with the main water molecules through van der Waals forces. Common guest molecules include methane, ethane, propane, carbon dioxide, cyclopentane and tetrahydrofuran. Carbon dioxide hydrate is used in air conditioning cold storage, seawater desalination, gas separation, carbon capture and storage, and replacement method for natural gas hydrate mining due to its unique properties. Since the formation conditions of carbon dioxide hydrate are relatively harsh, in order to reduce application energy consumption, it is usually used together with tetrahydrofuran hydrate, and is used in carbon dioxide storage and the collection and transportation of cold and heat energy.

[0003] In traditional technologies, the synthesis process of carbon dioxide hydrate has problems such as long induction time, large supercooling, slow growth rate and low conversion rate. The reason is that tetrahydrofuran (THF), as a guest molecule, only acts as a thermodynamic promoter and has no significant effect on the kinetic behavior of carbon dioxide hydrate synthesis. Compared with the synthesis of methane hydrate, there are obvious deficiencies in the kinetic promotion of carbon dioxide hydrate synthesis. Summary of the invention

[0004] The object of the present invention is to provide a method and device for efficiently preparing carbon dioxide hydrate to solve the problems raised in the above background technology.

[0005] In view of the above problems, the technical solution proposed by the present invention is: A method for efficiently preparing carbon dioxide hydrate comprises the following steps: Step 1: Evacuate the reaction vessel to ensure that there is no impurity gas in the device; Step 2: selecting graphene oxide, L-methionine, sodium dodecyl sulfate, and tetrahydrofuran, and configuring them to form a reaction solution; Step 3: adding the reaction solution into distilled water to prepare a mixed solution; Step 4: setting the temperature and pressure of the reaction vessel, determining the rotation speed of the stirring mechanism in the reaction vessel, and determining the duration of the ultrasonic oscillation; Step 5: injecting the mixed solution into the reaction container using a constant flow pump, and injecting carbon dioxide into the reaction container using a carbon dioxide gas cylinder; Step 6: react until carbon dioxide hydrate is fully generated, and take out the carbon dioxide hydrate from the reaction container.

[0006] As a preferred technical solution of the present invention, the mass concentration of graphene oxide in step 2 is 25 mg / L, the mass fraction of L-methionine is 0.3 wt %, the mass fraction of sodium dodecyl sulfate is 0.3 wt %, and the mass fraction of tetrahydrofuran is 4 wt %.

[0007] As a preferred technical solution of the present invention, the temperature in the reaction container in step 4 is 3° C., the pressure in the reaction container is 3-4 MPa, and the duration of the ultrasonic oscillation is 45-50 min.

[0008] On the other hand, the present invention provides an efficient preparation device of carbon dioxide hydrate, comprising: a reaction container, a carbon dioxide injection mechanism, and a water storage mechanism, the reaction container comprising a reactor, a motor is installed on the top of the reactor, and stirring blades, porous media, and zinc surface spacers are arranged in sequence from top to bottom inside the reactor, a stirring rod is connected between the output end of the motor and the stirring blade, a discharge port is provided on the side of the reactor below the zinc surface spacer, and a discharge pipe is connected to the discharge port, and a ball valve is connected to the free end of the discharge pipe, the carbon dioxide injection mechanism injects carbon dioxide into the reactor, and the water storage mechanism injects distilled water into the reactor.

[0009] As a preferred technical solution of the present invention, the carbon dioxide injection mechanism includes a carbon dioxide gas cylinder storing carbon dioxide, the top of the carbon dioxide gas cylinder is connected to a first angle valve, a first air pipe is connected between the output end of the first angle valve and the reactor, and the connection between the reactor and the first air pipe is located above the stirring blade.

[0010] As a preferred technical solution of the present invention, the water storage mechanism includes a water tank storing distilled water, a constant current pump is installed on the top of the water tank, a first water pipe is connected between the input end of the constant current pump and the water tank, a second water pipe is connected between the output end of the constant current pump and the water tank, and the top of the water tank is connected to a water inlet pipe.

[0011] As a preferred technical solution of the present invention, a water outlet pipe is installed inside the reactor above the stirring blade, a plurality of atomizing nozzles are connected to the side of the water outlet pipe, and the water outlet pipe is connected to the second water pipe.

[0012] As a preferred technical solution of the present invention, it also includes a nitrogen injection mechanism and a cooling mechanism, wherein the nitrogen injection mechanism includes a nitrogen gas cylinder storing nitrogen, the top of the nitrogen gas cylinder is connected to a second angle valve, a second air pipe is connected between the output end of the second angle valve and the reactor, a pressure gauge is connected to the outside of the reactor, and the top of the reactor is also connected to a pressure reducing valve; The cooling mechanism includes a chiller, a coil is installed inside the reactor below the zinc surface spacer, and the water outlet and water inlet of the chiller are respectively connected to the first cold water pipe and the second cold water pipe at both ends of the coil, and a thermometer is connected to the outside of the reactor.

[0013] As a preferred technical solution of the present invention, it also includes an ultrasonic oscillator, and the reaction kettle is placed on a workbench of the ultrasonic oscillator.

[0014] As a preferred technical solution of the present invention, it also includes an online thermal property measuring instrument, and the probe of the online thermal property measuring instrument is located at the inner bottom of the reactor.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: the efficient method and device for preparing carbon dioxide hydrate overcomes the problems of long induction time and low nucleation ratio in the synthesis of carbon dioxide hydrate by tetrahydrofuran by changing the configuration of the reaction solution and changing the concentration and mass fraction of each reactant constituting the reaction solution, thereby improving the rate of preparing carbon dioxide aqueous solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A method block diagram of a method for efficiently preparing carbon dioxide hydrate disclosed in an embodiment of the present invention; Figure 2 It is a schematic structural diagram of a highly efficient carbon dioxide hydrate preparation device disclosed in an embodiment of the present invention; Figure 3 It is a cross-sectional schematic diagram of a highly efficient device for preparing carbon dioxide hydrate disclosed in an embodiment of the present invention.

[0017] In the figure: 100, reaction vessel; 1001, reactor; 1002, motor; 1003, barometer; 1004, thermometer; 1005, pressure reducing valve; 1006, discharge pipe; 1007, ball valve; 1008, stirring rod; 1009, stirring blade; 1010, water outlet pipe; 1011, atomizing nozzle; 1012, porous medium; 1013, zinc surface spacer; 1014, coil; 200, ultrasonic oscillator; 300, carbon dioxide injection mechanism; 3 001, carbon dioxide gas cylinder; 3002, first angle valve; 3003, first air pipe; 400, nitrogen injection mechanism; 4001, nitrogen gas cylinder; 4002, second angle valve; 4003, second air pipe; 500, water storage mechanism; 5001, water tank; 5002, constant flow pump; 5003, second water pipe; 5004, water inlet pipe; 600, cooling mechanism; 6001, chiller; 6002, first cold water pipe; 700, online thermal property measuring instrument. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] See also Figure 1 The present invention provides a technical solution: a method for efficiently preparing carbon dioxide hydrate, comprising the following steps: Step 1: Evacuate the reaction vessel to ensure that there is no impurity gas in the device; Step 2: selecting graphene oxide, L-methionine, sodium dodecyl sulfate, and tetrahydrofuran, and configuring them to form a reaction solution; Step 3: adding the reaction solution into distilled water to prepare a mixed solution; Step 4: setting the temperature and pressure of the reaction vessel, determining the rotation speed of the stirring mechanism in the reaction vessel, and determining the duration of the ultrasonic oscillation; Step 5: injecting the mixed solution into the reaction container using a constant flow pump, and injecting carbon dioxide into the reaction container using a carbon dioxide gas cylinder; Step 6: react until carbon dioxide hydrate is fully generated, and take out the carbon dioxide hydrate from the reaction container.

[0020] In one embodiment of the present invention, further, in step 2, the mass concentration of graphene oxide is 25 mg / L, the mass fraction of L-methionine is 0.3 wt %, the mass fraction of sodium dodecyl sulfate is 0.3 wt %, and the mass fraction of tetrahydrofuran is 4 wt %.

[0021] Specifically, the amount of the reaction solution added is adjusted according to the capacity of distilled water.

[0022] According to an embodiment of the present invention, further, in step 4, the temperature in the reaction container is 3° C., the pressure in the reaction container is 3-4 MPa, and the duration of ultrasonic oscillation is 45-50 min.

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] See also Figure 2 - Figure 3 The present invention provides a technical solution: a highly efficient preparation device for carbon dioxide hydrate, comprising a reaction vessel 100, a carbon dioxide injection mechanism 300, and a water storage mechanism 500. The reaction vessel 100 comprises a reactor 1001. A motor 1002 is installed on the top of the reactor 1001. A stirring blade 1009, a porous medium 1012, and a zinc surface spacer 1013 are sequentially arranged inside the reactor 1001 from top to bottom. A stirring rod 1008 is connected between the output end of the motor 1002 and the stirring blade 1009. A discharge port is provided on the side of the reactor 1001 below the zinc surface spacer 1013, and a discharge pipe 1006 is connected to the discharge port. A ball valve 1007 is connected to the free end of the discharge pipe 1006. The carbon dioxide injection mechanism 300 injects carbon dioxide into the reactor 1001. The water storage mechanism 500 injects distilled water into the reactor 1001.

[0025] Specifically, after the distilled water and carbon dioxide are injected into the reactor 1001, the motor 1002 is used to drive the stirring blade 1009 to rotate, so that the distilled water and carbon dioxide can be fully mixed together. At the same time, the porous medium 1012 has a large number of pores and a high specific surface area. When carbon dioxide passes through, it can contact with more inner surfaces of the medium. Compared with the ordinary single phase, this provides more dissolution sites for carbon dioxide molecules, thereby increasing solubility. The pores in the porous medium 1012 are usually very small, which will produce capillary action, causing the distilled water to rise or fall in the pores, driving the carbon dioxide molecules into the pores. At the same time, in small-diameter pores, surface tension will cause the distilled water to form a curved interface , increasing the contact area between carbon dioxide molecules and distilled water, and reducing the energy required for carbon dioxide molecules to enter distilled water, thereby increasing solubility, and the zinc surface of the zinc surface spacer 1013 has a specific microstructure and chemical properties, which can provide a large number of active sites for the nucleation of carbon dioxide hydrates. When carbon dioxide gas and distilled water contact the zinc surface spacer 1013, these sites can promote the formation of hydrate nuclei, thereby shortening the nucleation induction time. The pores and channels of the zinc surface spacer 1013 can promote the diffusion of carbon dioxide gas in distilled water, making the carbon dioxide gas more evenly distributed in the water phase. Finally, the generated carbon dioxide hydrate flows out through the discharge pipe 1006.

[0026] In one embodiment of the present invention, further, the carbon dioxide injection mechanism 300 includes a carbon dioxide gas cylinder 3001 storing carbon dioxide, the top of the carbon dioxide gas cylinder 3001 is connected to a first angle valve 3002, a first air pipe 3003 is connected between the output end of the first angle valve 3002 and the reactor 1001, and the connection between the reactor 1001 and the first air pipe 3003 is located above the stirring blade 1009.

[0027] Specifically, by turning the first angle valve 3002 , high-pressure carbon dioxide can flow into the reaction kettle 1001 .

[0028] In one embodiment of the present invention, further, the water storage mechanism 500 includes a water tank 5001 for storing distilled water, a constant flow pump 5002 is installed on the top of the water tank 5001, a first water pipe is connected between the input end of the constant flow pump 5002 and the water tank 5001, a second water pipe 5003 is connected between the output end of the constant flow pump 5002 and the water tank 5001, and the top of the water tank 5001 is connected to a water inlet pipe 5004.

[0029] In one embodiment of the present invention, further, a water outlet pipe 1010 is installed inside the reactor 1001 above the stirring blade 1009, and a plurality of atomizing nozzles 1011 are connected to the side of the water outlet pipe 1010, and the water outlet pipe 1010 is connected to the second water pipe 5003.

[0030] Specifically, the reaction solution is added to the distilled water in the water tank 5001 using the water inlet pipe 5004, and then the mixed solution is pumped into the water outlet pipe 1010 using a constant flow pump and sprayed out through the atomizing nozzle 1011. The mixed solution sprayed out by the atomizing nozzle 1011 is in the form of water droplets, so it can increase the contact area with the carbon dioxide gas and increase the formation of carbon dioxide hydrate.

[0031] An embodiment of the present invention further includes a nitrogen injection mechanism 400 and a cooling mechanism 600. The nitrogen injection mechanism 400 includes a nitrogen gas cylinder 4001 storing nitrogen. The top of the nitrogen gas cylinder 4001 is connected to a second angle valve 4002. A second air pipe 4003 is connected between the output end of the second angle valve 4002 and the reactor 1001. A pressure gauge 1003 is connected to the outside of the reactor 1001. The top of the reactor 1001 is also connected to a pressure reducing valve 1005. Specifically, by turning the second angle valve 4002, high-pressure nitrogen can flow into the reactor 1001 to increase the pressure inside the reactor 1001. The user uses the pressure gauge 1003 to understand the internal pressure until the pressure rises to 3-4 MPa. At the same time, during the formation of hydrates, the pressure inside the reactor 1001 must always be maintained at 3-4 MPa. If the pressure exceeds this range, slowly open the pressure reducing valve 1005 to discharge the gas in the reactor 1001 to maintain the pressure at 3-4 MPa. When discharging carbon dioxide hydrate, the pressure reducing valve 1005 is also needed to reduce the pressure inside the reactor 1001.

[0032] The cooling mechanism 600 includes a chiller 6001, and a coil 1014 is installed inside the reactor 1001 below the zinc surface spacer 1013, and the water outlet and water inlet of the chiller 6001 are respectively connected to the first cold water pipe 6002 and the second cold water pipe at both ends of the coil 1014, and a thermometer 1004 is connected to the outside of the reactor 1001.

[0033] Specifically, the chiller 6001 generates cooling water at 2 to 3°C and injects it into the coil 1014 so that it absorbs the temperature in the reactor 1001. After the user knows through the thermometer 1004 that the temperature in the reactor 1001 reaches 3°C, the cooling of the reactor 1001 can be stopped. At the same time, during the hydrate formation period, the temperature of the reactor 1001 must always be maintained at 3°C.

[0034] An embodiment of the present invention further includes an ultrasonic oscillator 200, and the reaction kettle 1001 is placed on a workbench of the ultrasonic oscillator 200.

[0035] Specifically, the ultrasonic oscillator 200 can generate ultrasonic waves and transmit the ultrasonic waves to the reactor 1001 to increase the reaction rate between distilled water and carbon dioxide.

[0036] An embodiment of the present invention further includes an online thermal property measuring instrument 700 , and a probe of the online thermal property measuring instrument 700 is located at the inner bottom of the reaction kettle 1001 .

[0037] Specifically, the online thermophysical property measuring instrument 700 measures relevant thermophysical property parameters of carbon dioxide hydrate to help users understand the generation of carbon dioxide hydrate.

Claims

1. A method for efficiently preparing carbon dioxide hydrate, characterized in that: The following steps are involved: Step 1: Evacuate the reaction vessel to ensure that there is no impurity gas in the device; Step 2: selecting graphene oxide, L-methionine, sodium dodecyl sulfate, and tetrahydrofuran, and configuring them to form a reaction solution; Step 3: adding the reaction solution into distilled water to prepare a mixed solution; Step 4: setting the temperature and pressure of the reaction vessel, determining the rotation speed of the stirring mechanism in the reaction vessel, and determining the duration of the ultrasonic oscillation; Step 5: injecting the mixed solution into the reaction container using a constant flow pump, and injecting carbon dioxide into the reaction container using a carbon dioxide gas cylinder; Step 6: react until carbon dioxide hydrate is fully generated, and take out the carbon dioxide hydrate from the reaction container.

2. The method for efficiently preparing carbon dioxide hydrate according to claim 1, characterized in that: The mass concentration of graphene oxide in step 2 is 25 mg / L, the mass fraction of L-methionine is 0.3 wt %, the mass fraction of sodium dodecyl sulfate is 0.3 wt %, and the mass fraction of tetrahydrofuran is 4 wt %.

3. The method for efficiently preparing carbon dioxide hydrate according to claim 1, characterized in that: The temperature in the reaction container in step 4 is 3° C., the pressure in the reaction container is 3-4 MPa, and the duration of the ultrasonic oscillation is 45-50 min.

4. The device for efficiently preparing carbon dioxide hydrate according to claim 1, characterized in that: A highly efficient method for preparing carbon dioxide hydrate as described in claims 1 to 3, comprising a reaction vessel (100), a carbon dioxide injection mechanism (300), and a water storage mechanism (500), wherein the reaction vessel (100) comprises a reaction kettle (1001), a motor (1002) is installed on the top of the reaction kettle (1001), and the interior of the reaction kettle (1001) is provided with stirring blades (1009), porous media (1012), and zinc surface spacers (1013) in order from top to bottom, and the motor (1002) A stirring rod (1008) is connected between the output end and the stirring blade (1009), a discharge port is provided on the side of the reactor (1001) below the zinc surface spacer (1013), and a discharge pipe (1006) is connected to the discharge port, a ball valve (1007) is connected to the free end of the discharge pipe (1006), the carbon dioxide injection mechanism (300) injects carbon dioxide into the reactor (1001), and the water storage mechanism (500) injects distilled water into the reactor (1001).

5. The device for efficiently preparing carbon dioxide hydrate according to claim 4, characterized in that: The carbon dioxide injection mechanism (300) comprises a carbon dioxide gas cylinder (3001) storing carbon dioxide, the top of the carbon dioxide gas cylinder (3001) is connected to a first angle valve (3002), a first air pipe (3003) is connected between the output end of the first angle valve (3002) and the reactor (1001), and the connection between the reactor (1001) and the first air pipe (3003) is located above the stirring blade (1009).

6. The device for efficiently preparing carbon dioxide hydrate according to claim 4, characterized in that: The water storage mechanism (500) comprises a water tank (5001) storing distilled water, a constant flow pump (5002) being installed on the top of the water tank (5001), a first water pipe being connected between the input end of the constant flow pump (5002) and the water tank (5001), a second water pipe (5003) being connected between the output end of the constant flow pump (5002) and the water tank (5001), and a water inlet pipe (5004) being connected to the top of the water tank (5001).

7. The device for efficiently preparing carbon dioxide hydrate according to claim 6, characterized in that: A water outlet pipe (1010) is installed inside the reactor (1001) above the stirring blade (1009), and a plurality of atomizing nozzles (1011) are connected to the side of the water outlet pipe (1010). The water outlet pipe (1010) is connected to the second water pipe (5003).

8. The device for efficiently preparing carbon dioxide hydrate according to claim 4, characterized in that: It also comprises a nitrogen injection mechanism (400) and a temperature reduction mechanism (600), wherein the nitrogen injection mechanism (400) comprises a nitrogen gas cylinder (4001) storing nitrogen, the top of the nitrogen gas cylinder (4001) is connected to a second angle valve (4002), a second air pipe (4003) is connected between the output end of the second angle valve (4002) and the reactor (1001), the outside of the reactor (1001) is connected to a pressure gauge (1003), and the top of the reactor (1001) is also connected to a pressure reducing valve (1005); The cooling mechanism (600) comprises a water chiller (6001), a coil (1014) is installed inside the reactor (1001) below the zinc surface spacer (1013), and a water outlet and a water inlet of the water chiller (6001) are respectively connected to a first cold water pipe (6002) and a second cold water pipe at both ends of the coil (1014), and a thermometer (1004) is connected to the outside of the reactor (1001).

9. The device for efficiently preparing carbon dioxide hydrate according to claim 4, characterized in that: It also includes an ultrasonic oscillator (200), and the reaction kettle (1001) is placed on a workbench of the ultrasonic oscillator (200).

10. The device for efficiently preparing carbon dioxide hydrate according to claim 4, characterized in that: It also includes an online thermal property measuring instrument (700), wherein a probe of the online thermal property measuring instrument (700) is located at the inner bottom of the reaction kettle (1001).

Images