CN113318795B - Device and method for preparing liquid metal catalyst by plasma - Google Patents

Abstract

The invention discloses a device and a method for preparing a liquid metal catalyst by using plasma, wherein the device comprises a reaction chamber and a sealing cover, and the reaction chamber and the sealing cover form a containing cavity; an aeration head, an aeration pipe and a first electrode are arranged in the accommodating cavity, an insulating sleeve is arranged in the aeration pipe, and a second electrode is arranged in the insulating sleeve; one end of the aeration pipe is provided with an aeration head, the other end of the aeration pipe is provided with a sealing plug, and the second electrode is sealed with the aeration pipe through the sealing plug. The invention can form uniform and high-density plasmas, generate a large amount of active particles in a gas phase, and introduce a liquid phase to form activated water, and can effectively increase the catalytic forming rate of the liquid metal catalyst and improve the preparation efficiency of the liquid metal catalyst through the regulation and control of the types of active substances and the reaction temperature.

Description

Device and method for preparing liquid metal catalyst by plasma

technical field

The invention relates to the field of catalyst preparation, in particular to a device and method for preparing a liquid metal catalyst by plasma.

Background technique

As an extremely important part of catalysts, metal catalysts affect industrial production and human life in many ways, such as hydrogen production industry, chemical industry, electroplating industry, etc. The traditional methods of preparing metal catalysts mainly include impregnation method, atomic deposition method, reduction method, solid phase melting method, etc. The process of the above methods is cumbersome and time-consuming in the preparation process, and most of the raw materials contain toxic and harmful reagents. The environment has certain hazards. In view of the above problems, the rapid development of plasma technology in recent years is a good solution. At present, the plasma catalyst preparation technology mainly uses jet discharge, dielectric barrier discharge, glow discharge, etc. to prepare solid catalysts, but there are few studies on the preparation of liquid catalysts, especially liquid two-phase catalysts. In the preparation of liquid metal catalysts, the low efficiency of gas-liquid mass transfer has always been the bottleneck of catalyst preparation by gas-phase discharge. Therefore, it is imminent to develop efficient plasma preparation catalyst technology.

Contents of the invention

The invention provides a device and method for preparing a liquid metal catalyst by plasma to solve the problem of low gas-liquid mass transfer efficiency when preparing the liquid metal catalyst.

In order to achieve the above object, technical scheme of the present invention is:

A device for preparing a liquid metal catalyst by plasma, comprising: a reaction chamber and a sealing cover, the reaction chamber and the sealing cover constitute an accommodating cavity; an aeration head, an aeration tube, a first electrode and a target are arranged in the accommodating cavity metal salt solution, the aeration tube is provided with an insulating sleeve, and the insulating sleeve is provided with a second electrode;

An aeration head is provided at one end of the aeration tube, and a sealing plug is provided at the other end, and the second electrode is fixed in the aeration tube through the sealing plug. Further, the aeration pipe is provided with an air guide port.

Further, the aeration pipe is provided with several micropores, and the inner diameter of the micropores is 0.2-2 mm.

Further, a fastener is provided at one end of the first electrode, and the first electrode is fixed to the sealing cover through the fastener and placed in the target metal salt solution.

Further, the first electrode and the second electrode are made of stainless steel or other conductive materials.

Further, the power supply is one of pulse, direct current and alternating current power.

A method for preparing a liquid metal catalyst using a device for preparing a liquid metal catalyst using plasma, comprising the following steps:

Step 1: Prepare the target metal salt solution, adjust the pH value to 7-10, and place the configured target metal salt solution in the reaction chamber;

Step 2: Introduce carrier gas into the aeration tube and seal the device, apply voltage to the first electrode and the second electrode to form plasma, and control one or more of the discharge voltage, frequency and pulse width parameters to make the target metal The catalyst is gradually formed in solution.

Further, the concentration of the target metal salt solution in step 1 is 0.1-1 mol/L.

The invention provides a device and method for preparing a liquid metal catalyst by plasma, which utilizes the active material, temperature field and strong electric field generated by the low-temperature plasma to improve the preparation efficiency and catalytic activity of the catalyst; The way of pores improves the gas-liquid two-phase mass transfer efficiency and effectively improves the yield of liquid catalysts. The device and method overcome the shortcomings of the existing plasma preparation of liquid catalysts, and can realize uniform, large-scale and rapid preparation of catalysts under normal pressure.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a schematic structural diagram of a device for preparing a liquid metal catalyst by plasma in the present invention.

In the figure: 1. First electrode, 2. Sealing plug, 3. Air guide port, 4. Aeration tube, 5. Insulating sleeve, 6. Aeration head, 7. Fastener, 8. Sealing cover, 9. Reaction chamber, 10, second electrode, 11, target metal salt solution.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Fig. 1 is the device that plasma prepares liquid metal catalyst, comprises: reaction chamber 9 and sealing cover 8, and described reaction chamber 9 and sealing cover 8 constitute accommodating cavity; Aeration head 6, aeration tube are arranged in described accommodating cavity 4. The first electrode 1 and the target metal salt solution 11, the aeration tube 4 is provided with an insulating sleeve 5, and the insulating sleeve 5 is provided with a second electrode 10; preferably, the aeration tube 4 It is connected with the second electrode 10 from the inside to the outside according to the order of the second electrode 10, the insulating tube 5 and the aeration tube 4 through the insulating sleeve 5 and the sealing plug 2 of suitable size. The inner diameter of the insulating sleeve 5 is the same as the The outer diameter of the second electrode 10 is matched, and the inner diameter of the aeration tube 4 is about 1-20 mm larger than the outer diameter of the insulating sleeve 5; preferably, the distance between the inner wall of the aeration tube and the outer wall of the insulating sleeve is 1-5 mm.

One end of the aeration tube 4 is provided with an aeration head 6, and the other end is provided with a sealing plug 2, and the second electrode 10 is placed in the insulating sleeve 5 and fixed in the aeration tube 4 through the sealing plug 2 . It should be noted that when the first electrode 1 and the second electrode 10 are directly exposed to the reaction chamber 9, an electrolytic reaction will be formed, and plasma cannot be induced.

Further, the aeration pipe 4 is provided with an air guide port 3 . Gas is passed into the aeration pipe 4 through the air guide port 3 .

Further, the aeration pipe 4 is provided with several micropores, and the inner diameter of the micropores is 0.2-2mm. Preferably, the number of micropores is 4 to 20; when using the device, gas is first introduced into the aeration tube 4 to prevent liquid from entering the insulating sleeve 5 through the micropores and contacting the second metal electrode 10, and the plasma is in the gas phase Initiated, blown into the liquid phase by aeration.

Further, a fastener 7 is provided at one end of the first electrode 1 , and the first electrode 1 is fixed to the sealing cover 8 through the fastener 7 .

Further, the first electrode 1 and the second electrode 10 are made of stainless steel or other conductive materials.

Further, the power supply is one of pulse, direct current and alternating current power.

A method for preparing a liquid metal catalyst using a device for preparing a liquid metal catalyst using plasma, comprising the following steps:

Step 1: Prepare the target metal salt solution, adjust the pH value to 7-10, and place the configured target metal salt solution in the reaction chamber 9;

Step 2: Pass the carrier gas into the aeration tube 4 and seal the device, apply voltage to the first electrode 1 and the second electrode 10 to form plasma, and control one or more of the discharge voltage, frequency and pulse width parameters , so that the target metal catalyst is gradually generated in the solution.

Further, the concentration of the target metal salt solution 11 described in step 1 is 0.1-1 mol/L. Preferably, a weak base solution or a strong base and weak salt solution is used to adjust the pH value of the target metal salt solution.

When using this device to prepare a liquid metal catalyst, the electrodes are respectively connected to the high-voltage end of the power supply and the ground end, and when the first electrode 1 is grounded, the target metal salt solution can be used to directly ground the first electrode outside the aeration tube 4. Electrode 1, the plasma is induced between the insulating sleeve 5 and the aeration tube 4, when the insulating sleeve 5 has micropores, the plasma can directly contact the liquid; the active material generated by the discharge will be ventilated through the gas guide port 3 The gas is blown into the reaction solution through the aeration head 6, and the gas type and flow rate can be adjusted according to the reaction requirements. The control of the gas flow rate is controlled by a flow meter to ensure that the pressure generated by the ventilation prevents the liquid outside the air guide tube from entering between the air guide tube and the insulating sleeve through the aeration head or micropores, thereby extinguishing the plasma. The type of gas is replaced by changing the target gas cylinder, and the target gas is selected according to the participation of oxidizing (choose air, oxygen, etc.) or reducing (choose hydrogen, ammonia, etc.) substances in the reaction process. Concrete embodiment situation is as follows:

Example 1, dissolve oxalic acid and nickel nitrate with a molar ratio of 1:1 in water, and use potassium carbonate to adjust the pH value of the solution to 10 as the reaction solution for preparing the catalyst, discharge it with an AC source, pass oxygen during the discharge process, and the oxygen flow rate is 200mL /min. When the discharge voltage is 5kV, the discharge frequency is 3kHz, and the discharge time is 20min, the solution can be clearly separated into layers, and an oil-soluble nickel oxalate catalyst and a water-soluble catalyst rich in active oxygen components can be obtained respectively. The obtained oil-soluble and water-soluble catalysts were used in the catalytic upgrading of heavy oil at a volume ratio of 3:1, where the viscosity of the heavy oil at 20°C was 2016.66 mPa·s. The experimental results show that when the reaction temperature is 290°C and the reaction time is 24 hours, the viscosity of the heavy oil is 403.33mPa·s, the viscosity reduction rate reaches 80%, and the colloid and asphaltene content are significantly reduced.

Example 2, dissolving ammonium heptamolybdate and nickel nitrate with a molar ratio of 1:7 in water, adding oleic acid and using ammonium hydroxide to adjust the pH value of the solution to 8 as the reaction solution for preparing the catalyst, discharging with a pulse source, during the discharge process Ventilate the air, the air flow rate is 500mL/min. When the peak voltage is 25kV, the discharge frequency is 5kHz, the pulse width is 10μs, and the discharge time is 15min, a nickel molybdate bimetallic catalyst rich in active oxygen components can be obtained. The prepared catalyst is used in the catalytic upgrading of heavy oil. The experimental results show that the reaction temperature is 290°C, the reaction time is 24 hours, the viscosity reduction rate reaches 90%, and the API degree increases by 5.2.

Embodiment three, adopt 1mol/L silver nitrate solution, control pH value to be 7, discharge with direct current source, open 8 micropores that diameter is 0.5mm in aeration pipe, and prepare liquid state with the hydrogen of flow rate 150mL/min as carrier gas nanosilver catalyst. When the discharge voltage is 2kV and the discharge time is 30min, the nano-silver catalyst with a particle size of 5-30nm can be obtained.

The invention adopts the plasma method to prepare the liquid metal catalyst. Compared with the traditional catalyst preparation method, it is more rapid, uniform and efficient, and the catalyst can be produced in a large amount in only tens of minutes; The introduction into the liquid catalyst increases the activity of the catalyst; in addition, the preparation temperature of the catalyst can be effectively controlled by adjusting the discharge parameters. The catalyst prepared by this method has strong practical value and application prospect in heavy oil upgrading and other applications.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present invention. scope.

Claims (8)

1. An apparatus for preparing a liquid metal catalyst by plasma, comprising: the reaction chamber (9) and the sealing cover (8), wherein the reaction chamber (9) and the sealing cover (8) form a containing cavity; an aeration head (6), an aeration pipe (4), a first electrode (1) and a target metal salt solution (11) are arranged in the accommodating cavity, an insulating sleeve (5) is arranged in the aeration pipe (4), and a second electrode (10) is arranged in the insulating sleeve (5); the electrodes are respectively connected with a power high-voltage end and a grounding end, and when the first electrode (1) is grounded, the first electrode (1) outside the aerator pipe (4) can be omitted by utilizing the target metal salt solution (11) to be directly grounded;

one end of the aeration pipe (4) is provided with an aeration head (6), the other end of the aeration pipe is provided with a sealing plug (2), and the second electrode (10) is fixed in the aeration pipe (4) through the sealing plug (2).

2. An apparatus for preparing a liquid metal catalyst by means of plasma according to claim 1, characterized in that the aeration tube (4) is provided with a gas-guiding opening (3).

3. The apparatus for preparing a liquid metal catalyst by using plasma according to claim 2, wherein the aeration pipe (4) is provided with a plurality of micropores, and the inner diameter of the micropores is 0.2-2 mm.

4. An apparatus for preparing a liquid metal catalyst by means of plasma according to claim 1, characterized in that one end of the first electrode (1) is provided with a fastener (7), and the first electrode (1) is fixed with the sealing cover (8) by means of the fastener (7) and placed in the target metal salt solution (11).

5. An apparatus for preparing a liquid metal catalyst according to claim 1, characterized in that the first electrode (1) and the second electrode (10) are made of stainless steel or other electrically conductive material.

6. The apparatus for preparing a liquid metal catalyst by using plasma according to claim 1, wherein the power source is one of a pulse, a direct current and an alternating current power source.

7. A method for preparing a liquid metal catalyst based on the apparatus for preparing a liquid metal catalyst by plasma according to any one of claims 1 to 6, comprising the steps of:

step 1: preparing a target metal salt solution (11), adjusting the pH value to 7-10, and placing the prepared target metal salt solution into a reaction chamber (9);

step 2: and introducing carrier gas into the aeration pipe (4) and sealing the device, applying voltage to the first electrode (1) and the second electrode (10) to form plasma, and gradually generating the target metal catalyst in the solution by controlling one or more of discharge voltage, frequency and pulse width parameters.

8. The method for preparing a liquid metal catalyst by using a plasma apparatus for preparing a liquid metal catalyst according to claim 7, wherein the concentration of the target metal salt solution (11) in the step 1 is 0.1 to 1mol/L.

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