CN110882665A

CN110882665A - Plasma reactor, reaction device and method for preparing acetylene by cracking heavy oil with plasma

Info

Publication number: CN110882665A
Application number: CN201910990986.4A
Authority: CN
Inventors: 张帅; 邵涛; 孙昊; 范喆; 高远
Original assignee: Institute of Electrical Engineering of CAS
Current assignee: Institute of Electrical Engineering of CAS
Priority date: 2019-10-17
Filing date: 2019-10-17
Publication date: 2020-03-17

Abstract

The invention provides a plasma reactor, a reaction device and a method for preparing acetylene by cracking heavy oil with plasma, wherein the method for preparing acetylene by cracking heavy oil comprises the following steps: evacuating air in the plasma reactor, switching on a pulse power supply, introducing heavy oil and working gas into the plasma reactor for cracking after discharge is stable, and cooling and separating a cracking product to obtain acetylene; the plasma is generated by adopting a pulse power supply to drive discharge, the gas in the plasma area in the reactor cavity can be heated to more than 2000 ℃ within ns-mus order time by utilizing the rising edge, the falling edge and the narrow pulse width of the plasma, the temperature can also be rapidly reduced after the plasma is maintained for a short time, the problems of acetylene polycondensation, high coke yield and low acetylene yield caused by overhigh temperature duration are prevented, and meanwhile, the requirements on the heat resistance and the insulating property of the insulating material of the plasma reactor are lower.

Description

Plasma reactor, reaction device and method for preparing acetylene by cracking heavy oil with plasma

Technical Field

The invention relates to the technical field of petrochemical industry, in particular to a plasma reactor, a reaction device and a method for preparing acetylene by cracking heavy oil with plasma.

Background

The heavy oil is the residual heavy oil after extracting gasoline and diesel oil from crude oil, and is characterized by large molecular weight and high viscosity. Under the condition that petroleum resources are gradually reduced and the properties of crude oil are gradually deteriorated in the oil refining industry of various countries in the world, heavy oil becomes an important strategic alternative energy source, so that how to realize high-efficiency conversion and utilization of the heavy oil becomes an important research direction in the petrochemical industry.

At present, the preparation of olefin by heavy oil cracking becomes a main research direction for realizing high-efficiency conversion and utilization of heavy oil in the petrochemical industry, and the heavy oil cracking technology not only can obtain higher selectivity of low-carbon olefin, but also improves the flexibility of the distribution of cracked products, and is an effective means for lightening heavy oil.

At present, most of the existing plasma technology for cracking heavy oil to prepare acetylene is adopted, for example, chinese patent document CN106866334A discloses a thermal plasma cracking treatment method for asphaltenes, which specifically comprises the following steps: a) spraying asphaltenes generated by the poor-quality heavy oil solvent deasphalting process into a thermal plasma reactor through an atomizing device; b) in the thermal plasma reactor, mixing and reacting with hydrogen thermal plasma jet to obtain a cracking product; c) the cracking product passes through a gas-solid fast separation device to obtain a solid phase product and a gas phase product with the temperature of 1600-; the solid-phase product is a solid carbon material; d) and the gas-phase product enters a quenching device to obtain pyrolysis gas containing acetylene, hydrogen and methane.

However, the thermal plasma disclosed in the above patent documents is a thermal plasma torch excited by a direct current or alternating current power supply, and the cracked product needs to be introduced into a gas-solid separation device, and the obtained gas is introduced into a quenching device to be cooled, and thus the temperature is continuously too high, which causes problems such as decrease in acetylene yield, increase in coke yield, and low energy efficiency.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to overcome the defects that in the prior art, in the process of preparing acetylene by cracking heavy oil by adopting thermal plasma, thermal plasma is generated by adopting direct current or alternating current power supply excitation, the acetylene yield is reduced, the coke yield is high, the energy efficiency utilization efficiency is low and the like due to continuous overhigh temperature, so that a plasma reactor, a reaction device and a method for preparing acetylene by cracking heavy oil by using plasma are provided, the acetylene yield and the energy utilization rate are improved, and the coke yield is reduced.

Therefore, the invention provides the following technical scheme:

the invention provides a method for preparing acetylene by cracking heavy oil with plasma, which comprises the following steps:

and (3) evacuating air in the plasma reactor, switching on a pulse power supply, introducing heavy oil and working gas into the plasma reactor for cracking after discharge is stable, and cooling and separating a cracking product to obtain acetylene.

The pulse voltage of the pulse power supply is 5-50kV, the frequency is 1-100kHz, and the rising edge, the falling edge and the pulse width of the pulse voltage are 10-10000 ns.

Separating the gaseous product obtained by cracking to obtain acetylene and hydrogen-rich gas, and circulating the hydrogen-rich gas back to the plasma reactor to replace part of working gas; and cooling the heavy oil residue obtained by cracking, and then flowing out of the plasma reactor.

The hydrogen-rich gas refers to hydrogen, methane, ethane and other gases.

The working gas is hydrogen, the flow rate of the working gas is 10-1000ml/min, and the pressure is 0.1-1 MPa.

Evacuating air in the plasma reactor with an auxiliary gas, wherein the auxiliary gas is helium or argon; the flow rate of the auxiliary gas is 10-1000ml/min, and the pressure is 0.1-1 MPa.

The flow rate of the heavy oil entering the plasma reactor is 0.1-2 g/min.

And cooling the electrode of the plasma reactor.

The heavy oil is at least one of atmospheric residue, vacuum residue, cracked diesel oil, catalytic diesel oil, deasphalted oil, oil shale oil or coal tar.

The present invention also provides a plasma reactor comprising:

the reactor cavity is formed by enclosing a first insulating support plate, an insulating side wall and a second insulating support plate, wherein the first insulating support plate is provided with an air inlet, a liquid inlet and a high-voltage electrode, and the high-voltage electrode is externally connected with a pulse power supply;

the low-voltage electrode is positioned in the reactor cavity, is opposite to the high-voltage electrode and is used for grounding;

the cooling medium nozzle is arranged on the insulating side wall and is positioned at the lower part of the reactor cavity;

the air outlet is arranged on the insulating side wall and is positioned above the low-voltage electrode;

and the liquid outlet is arranged on the second insulating supporting plate.

The reaction region refers to a region between the high voltage electrode and the low voltage electrode.

A first cooling device is arranged outside the high-voltage electrode;

and a second cooling device is arranged outside the low-voltage electrode.

The distance between the high-voltage electrode and the low-voltage electrode is 0.5-50mm, so that the phenomenon that the power supply is damaged due to too small distance between the two electrodes or the discharge cannot be caused due to too large distance between the two electrodes is avoided.

The structure of the plasma reactor is any one of a needle-plate structure, a needle-needle structure and a plate-plate structure.

The plasma reactor is in a needle-plate structure, wherein the low-voltage electrode is a metal disc grounding electrode, and the high-voltage electrode is in a metal rod shape or a needle shape; preferably, the high voltage electrode is not less than one, and is in the form of an array or a round cluster.

The high-voltage electrode and/or the low-voltage electrode are made of any one of tungsten, stainless steel or copper;

and/or the discharge in the plasma reactor is in the form of spark discharge or sliding arc discharge;

and/or the insulating side wall is made of any one of glass, quartz, polytetrafluoroethylene and ceramic.

The invention also provides a reaction device which comprises the plasma reactor.

The reaction apparatus further comprises:

the inlet of the gas separation tower is communicated with the gas outlet of the plasma reactor, and the gas separation tower is provided with a hydrogen-rich gas outlet and an acetylene outlet;

the acetylene collecting tower is communicated with an acetylene outlet on the gas separation tower;

and the heavy oil collecting tower is communicated with the liquid outlet of the plasma reactor.

The hydrogen-rich gas outlet is communicated with the gas inlet of the plasma reactor.

And the outlet of the heavy oil collecting tower is communicated with the liquid inlet of the plasma reactor through a liquid phase pump.

The technical scheme of the invention has the following advantages:

1. the inventor of the method for preparing acetylene by cracking heavy oil by using the plasma, which is provided by the invention, researches show for the first time that the plasma can heat the gas in a reactor cavity to more than 2000 ℃ within ns-mus order of time by adopting a pulse power supply to drive discharge and utilizing the rising edge, the falling edge and the narrow pulse width of the discharge, the temperature can also be rapidly reduced after the plasma is maintained for a short time, the problems of acetylene polycondensation, high coke yield and low acetylene yield caused by overhigh temperature can be effectively prevented, and meanwhile, the requirements on the heat resistance and the insulating property of an insulating material of a plasma reactor are lower.

2. According to the method for preparing acetylene by cracking heavy oil with plasma, acetylene and hydrogen-rich gas are obtained by separation, and the hydrogen-rich gas is recycled to replace part of working gas, so that the cost can be reduced, the further cracking of acetylene is limited, the acetylene yield and the energy utilization efficiency are improved, and the possible coking or carbon deposition phenomenon is reduced or avoided; and the heavy oil residue after reaction and the generated gas are cooled in the cavity of the plasma reactor, so that the problems of acetylene polycondensation, high coke yield and low acetylene yield caused by continuous overhigh temperature are further prevented while the consumption of a cooling medium is reduced, and meanwhile, the gas-liquid quick separation can be realized in the cavity of the reactor.

3. The method for preparing acetylene by cracking heavy oil with plasma provided by the invention can improve the yield of acetylene and reduce the yield of acetylene polycondensation and coke by controlling the rate of the heavy oil sample entering the plasma reactor.

4. The inventor of the plasma reactor provided by the invention researches and discovers for the first time that the plasma can heat the gas in the cavity of the reactor to more than 2000 ℃ within ns-mus order time by adopting a pulse power supply to drive discharge and utilizing the rising edge, the falling edge and the narrow pulse width of the pulse power supply, and the temperature can be rapidly reduced after the plasma is maintained for a short time, so that the problems of acetylene polycondensation, high coke yield and low acetylene yield caused by overhigh temperature can be effectively prevented, and meanwhile, the requirements on the heat resistance and the insulating property of an insulating material of the plasma reactor are lower.

5. According to the plasma reactor provided by the invention, the cooling medium nozzle is arranged on the side wall below the reaction area in the reactor cavity, so that the cooling of heavy oil residues and reaction generated gas in the plasma reactor is accelerated, the problems of acetylene polycondensation, high coke yield and low acetylene yield caused by continuous overhigh temperature are further prevented, and meanwhile, the gas-liquid rapid separation can be realized in the reactor cavity.

6. According to the plasma reactor provided by the invention, the electrode cooling device is arranged outside the electrode to cool the electrode, so that the heat damage to the insulating material near the electrode can be reduced.

7. According to the plasma reactor provided by the invention, the high-voltage electrodes are arranged in an array or round cluster form, and a plurality of electrodes can be synchronously excited by pulse discharge to generate a large amount of plasma, so that the heavy oil treatment efficiency is increased, the acetylene yield is further improved, and the energy consumption is saved.

8. The reaction device provided by the invention can effectively improve the acetylene yield and the energy utilization rate and reduce the coke yield by adopting the plasma reactor, and simultaneously can realize the rapid gas-liquid separation in the cavity of the plasma reactor and reduce the dosage of a cooling medium.

9. According to the reaction device provided by the invention, the acetylene collecting tower is arranged, the hydrogen-rich gas outlet is communicated with the gas inlet of the plasma reactor, the hydrogen-rich gas is recycled to replace part of working gas, the cost can be reduced, the acetylene is limited from being further cracked, the acetylene yield and the energy utilization efficiency are improved, and the possible coking or carbon deposition phenomenon is reduced or avoided; the outlet of the heavy oil collecting tower is communicated with the liquid inlet of the plasma reactor through a liquid phase pump, and heavy oil residues circularly enter the plasma reactor to be cracked again, so that the yield of acetylene is further improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic view of a plasma reactor according to the present invention;

FIG. 2 is a schematic flow chart of a process for preparing acetylene by plasma cracking of heavy oil in example 3 according to the present invention;

description of reference numerals:

1. an auxiliary gas; 2. a pulse power supply; 3. a liquid phase pump; 4. a plasma reactor; 5. a gas separation column; 6. an acetylene collection column; 7. a heavy oil collection tower; 11. an air inlet; 12. a high voltage electrode; 13. a liquid inlet; 14. a first insulating support plate; 15. an air outlet; 16. a metal disc; 17. an insulating sidewall; 18. a cooling medium nozzle; 19. a liquid outlet; 20. a first cooling device; 21. a second insulating support plate; 22. a second cooling device; 23. and a low voltage electrode.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "connected" and "communicating" are to be interpreted broadly, e.g., as being either fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Example 1

The present embodiment provides a plasma reactor, as shown in fig. 1, comprising a reactor cavity formed by a first insulating support plate 14, a second insulating support plate 21 and an insulating sidewall 17, wherein the first insulating support plate 14 of the reactor cavity is provided with a high voltage electrode 12, an air inlet 11 and a liquid inlet 13, the second insulating support plate 21 is provided with a low voltage electrode 23 and a liquid outlet 19, and the insulating sidewall 17 of the reactor cavity sidewall is provided with an air outlet 15 and a cooling medium nozzle 18;

the high voltage electrode 12 is inserted into the reactor cavity through the first insulating support plate 14 of the reactor cavity, the low voltage electrode 23 is positioned in the reactor cavity, penetrates through the second insulating support plate 21 of the reactor cavity and is grounded;

wherein the cooling medium nozzle 18 is positioned at the lower part of the gas outlet 15, and the cooling medium nozzle 18 is positioned below the reaction zone in the reactor cavity; the reaction region refers to a region between the high voltage electrode and the low voltage electrode.

Through setting up the cooling medium nozzle at reactor cavity lateral wall, can accelerate the cooling to the heavy oil residue after the reaction and gaseous in the plasma reactor, when reducing cold water quantity and carbon dioxide output, prevent to lead to the fact acetylene polycondensation, the big and low problem of acetylene yield of coke output because of the temperature lasts too high, can also realize gas-liquid quick separation in the reactor cavity simultaneously.

Specifically, a first cooling device 20 (in this embodiment, an electrode water cooling device) is disposed on the outer side of the high-voltage electrode 12 and sleeved on the high-voltage electrode 12, a second cooling device 22 (in this embodiment, an electrode water cooling device) is disposed on the contact portion of the low-voltage electrode 23 and the second insulating support plate 21 and sleeved on the low-voltage electrode 23, and the electrode is cooled by the electrode water cooling device, so that thermal damage to the insulating material near the electrode can be reduced.

Specifically, the distance between the high-voltage electrode 12 and the low-voltage electrode 23 is 0.5-50mm, so that the phenomenon that the power supply is damaged due to the fact that the distance between the two electrodes is too small or the discharge cannot be performed due to the fact that the distance between the two electrodes is too large is avoided. In the present embodiment, the distance between the high voltage electrode 12 and the low voltage electrode 23 is 10 mm.

Specifically, the material of the high voltage electrode 12 and/or the low voltage electrode 23 is tungsten;

specifically, the structure of the plasma reactor is a needle-plate structure, wherein the low-voltage electrode 23 is a metal disc grounding electrode, and the high-voltage electrode 12 is a rod-shaped high-voltage electrode;

in another embodiment of the high voltage electrode, the high voltage electrode may be a needle-shaped high voltage electrode.

As still another embodiment of the above high voltage electrode, the rod-shaped or needle-shaped high voltage electrodes are 10 and are in an array form, and the high voltage electrodes are arranged in an array or a circular cluster form, so that a plurality of electrodes can be synchronously excited by pulse discharge to generate a large amount of plasma, thereby increasing the heavy oil treatment efficiency, further improving the acetylene yield, improving the energy utilization rate and saving the energy consumption.

As another embodiment of the above plasma reactor structure, the plasma reactor may also be a pin-pin structure or a plate-plate structure.

In particular, the discharge in the plasma reactor is in the form of a spark discharge.

Specifically, the pulse waveform of the pulse power supply is triangular; the pulse voltage is 8-10kV, the frequency is 5kHz, and the rising edge, the falling edge and the pulse width of the pulse voltage are all 500 ns.

Specifically, the first insulating support material, the second insulating support material and the insulating side wall are all made of glass.

Example 2

As shown in fig. 2, this embodiment provides a reaction apparatus, comprising the plasma reactor of embodiment 1, further comprising,

the inlet of the gas separation tower 5 is communicated with the gas outlet 15 on the side wall of the plasma reactor 4, and the first outlet of the gas separation tower 5 is communicated with the gas inlet 11 on the first insulating support plate 14;

the heavy oil collecting tower 7 is communicated with the liquid outlet 19 on the second insulating support plate 21, and the heavy oil collecting tower 7 is communicated with the liquid inlet 13 on the first insulating support plate 14 through the liquid phase pump 3;

an acetylene collecting column 6, wherein the acetylene collecting column 6 is communicated with a second outlet of the gas separation column 5;

the acetylene is separated into the acetylene collecting tower by arranging the gas separating tower and the acetylene collecting tower, and the hydrogen-rich gas is circularly introduced into the plasma reactor to replace part of working gas, so that the further cracking of the acetylene is limited, the acetylene yield and the energy utilization efficiency are improved, and the possible coking or carbon deposition phenomenon is reduced or avoided; the heavy oil residue circularly enters the plasma reactor for cracking again by arranging the heavy oil collecting tower, so that the yield of acetylene is improved.

The reaction device provided by the invention can effectively improve the acetylene yield and the energy utilization rate and reduce the coke yield by adopting the plasma reactor, and simultaneously can realize the rapid gas-liquid separation in the cavity of the plasma reactor and reduce the dosage of a cooling medium.

Example 3

This example provides a method for preparing acetylene by cracking heavy oil using the reaction apparatus described in the above example 2, as shown in fig. 1 and 2, comprising the following steps:

firstly, setting the distance between electrodes to be 10 mm; then, the auxiliary gas 1 argon is communicated with the gas inlet 11 of the plasma reactor 4, the air in the device is evacuated for 10min at the flow rate of 100ml/min, then the working gas hydrogen is communicated with the gas inlet 11 of the plasma reactor 4, and the reactor is cleaned for 10min at the flow rate of 50 ml/min; then, a pulse power supply 2 is switched on, a first cooling device 20 (an electrode water cooling device is adopted in the embodiment), a second cooling device 22 (an electrode water cooling device is adopted in the embodiment) and a cooling medium nozzle 18 (the cooling medium is high-speed water in the embodiment, the spraying speed is 30m/s), at the moment, the power supply is switched on, the rising edge and the falling edge of pulse parameters are both 500ns, the frequency is 5kHz, the discharging voltage is 8kV, and spark discharging plasma is generated;

after the discharge is stabilized, the liquid phase pump 3 is turned on, the heavy oil sample (in this example, catalytic cracking diesel oil) is introduced into the plasma reactor 4 through the liquid inlet 13 at a rate of 0.1g/min, and the pulse parameters are adjusted: triangular waves, wherein the rising edge and the falling edge are both 500ns, the frequency is 5kHz, the discharge voltage is 10kV, and the discharge power is 50W, so that the discharge is stable;

gaseous products obtained by cracking heavy oil in the plasma reactor 4 are introduced into the gas separation tower 5 through the gas outlet 15, acetylene obtained by separation in the gas separation tower 5 enters the acetylene collecting tower 6, and hydrogen-rich gas (hydrogen, methane, ethane and other gases) circularly enters the plasma reactor 4 through the gas inlet 11;

after the cracking products in the plasma reactor 4 are cooled by water sprayed by a cooling medium nozzle 18, the obtained heavy oil residues enter a heavy oil collecting tower 7 through a liquid outlet 19, and then enter the plasma reactor 4 at the speed of 0.1g/min through circulation of a liquid phase pump 3;

the whole cracking process lasts for 1h in total.

Comparative example

This comparative example provides a method for preparing acetylene by cracking heavy oil using an apparatus similar to the reaction apparatus described in example 2 above, except that a direct current power source is used as the power source in this comparative example, comprising the steps of:

firstly, setting the distance between electrodes to be 10 mm; then, the auxiliary gas 1 argon is communicated with the gas inlet 11 of the plasma reactor 4, the air in the device is evacuated for 10min at the flow rate of 100ml/min, then the working gas hydrogen is communicated with the gas inlet 11 of the plasma reactor 4, and the reactor is cleaned for 10min at the flow rate of 50 ml/min; then, a power supply is switched on (a direct current power supply is adopted in the comparative example), a first cooling device 20 (an electrode water cooling device is adopted in the comparative example), a second cooling device 22 (an electrode water cooling device is adopted in the comparative example) and a cooling medium nozzle 18 (a cooling medium in the comparative example is high-speed water, and the spraying speed is 30m/s) are switched on, and spark discharge is adopted;

after the discharge is stable, the liquid phase pump 3 is opened, and a heavy oil sample (catalytic cracking diesel oil is adopted in the comparative example) is introduced into the plasma reactor 4 through the liquid inlet 13 at the speed of 0.1 g/min;

after the cracking products in the plasma reactor 4 are cooled by water sprayed by a cooling medium nozzle, the obtained heavy oil residues enter a heavy oil collecting tower 7 through a liquid outlet 19, and then enter the plasma reactor 4 at the speed of 0.1g/min through circulation of a liquid phase pump 3;

the whole cracking process lasts for 1h in total.

Examples of the experiments

Acetylene and hydrogen-rich gas prepared in example 3 and comparative example were measured by gas chromatography using the SammerfleTRACEGC 1300 series. The results of the measurements are shown in Table 1 below.

Calculation formula of coke yield: coke yield ═ coke formation ÷ heavy oil consumption x 100%;

the calculation formula of the energy utilization efficiency is as follows: the energy utilization efficiency is the calorific value increased by the product after reaction divided by the electric energy consumed in the cracking process x100 percent,

the added heat value of the products after the reaction is the sum of the heat values of the products after the reaction-heavy oil consumption x the heat value of the diesel oil.

TABLE 1 examination results of the products obtained in Experimental example 3 and comparative example, coke productivity and energy utilization

From the data in the above table, it can be seen that the pulse power supply is used to drive the discharge, and the plasma can heat the gas in the reactor cavity to above 2000 ℃ in ns-mus time by using the rising edge, the falling edge and the narrow pulse width, and the temperature will rapidly drop after the short time maintenance, compared with the common direct current power supply to drive the discharge, the acetylene yield and the energy utilization rate can be effectively improved, the coke yield is obviously reduced, and no propane and butane can be detected by using the common direct current power supply to drive the discharge to crack the heavy oil.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of the invention may be made without departing from the spirit or scope of the invention.

Claims

1. A method for preparing acetylene by plasma cracking of heavy oil is characterized by comprising the following steps:

2. The method for preparing acetylene by plasma cracking heavy oil according to claim 1, wherein the pulse voltage of the pulse power supply is 5-50kV, the frequency is 1-100kHz, and the rising edge, the falling edge and the pulse width of the pulse voltage are 10-10000 ns.

3. The method for preparing acetylene by cracking heavy oil through plasma according to claim 1 or 2, wherein the gaseous product obtained by cracking is separated to obtain acetylene and hydrogen-rich gas, and the hydrogen-rich gas is recycled to the plasma reactor to replace part of working gas; and cooling the heavy oil residue obtained by cracking, and then flowing out of the plasma reactor.

4. The method for preparing acetylene by plasma cracking of heavy oil according to claim 1 or 2, wherein the working gas is hydrogen, the flow rate of the working gas is 10-1000ml/min, and the pressure is 0.1-1 MPa.

5. The method for preparing acetylene by plasma cracking of heavy oil according to claim 1 or 2, wherein air in the plasma reactor is evacuated with an auxiliary gas, wherein the auxiliary gas is helium or argon; the flow rate of the auxiliary gas is 10-1000ml/min, and the pressure is 0.1-1 MPa.

6. The method for preparing acetylene by plasma cracking of heavy oil according to claim 1 or 2, wherein the flow rate of the heavy oil into the plasma reactor is 0.1-2 g/min.

7. The method for preparing acetylene by plasma cracking of heavy oil according to claim 1 or 2, wherein the electrode of the plasma reactor is subjected to a cooling treatment.

8. The method for producing acetylene by plasma cracking of heavy oil according to any one of claims 1 to 7, wherein the heavy oil is at least one of atmospheric residue, vacuum residue, cracked diesel, catalytic diesel, deasphalted oil, oil shale oil or coal tar.

9. A plasma reactor, comprising:

and the liquid outlet is arranged on the second insulating supporting plate.

10. The plasma reactor according to claim 9, wherein the high voltage electrode is externally provided with a first cooling device;

and a second cooling device is arranged outside the low-voltage electrode.

11. A plasma reactor according to claim 9 or 10, characterized in that the distance between the high voltage electrode and the low voltage electrode is 0.5-50 mm.

12. The plasma reactor according to claim 11, wherein the structure of the plasma reactor is any one of a pin-plate structure, a pin-pin structure, and a plate-plate structure.

13. The plasma reactor according to any one of claims 9 to 12, wherein the structure of the plasma reactor is a pin-plate structure, wherein the low voltage electrode is a metal disk ground electrode, and the high voltage electrode is a metal rod or a pin; preferably, the high voltage electrode is not less than one, and is in the form of an array or a round cluster.

14. The plasma reactor according to claim 13, wherein the material of the high voltage electrode and/or the low voltage electrode is any one of tungsten, stainless steel or copper;

15. A reactor apparatus comprising a plasma reactor as claimed in any one of claims 9 to 14.

16. The reactor device of claim 15, further comprising:

17. The reactor apparatus of claim 16, wherein the hydrogen rich gas outlet is in communication with a gas inlet of the plasma reactor.

18. The reactor apparatus of claim 16, wherein the outlet of the heavy oil collection column is in communication with the liquid inlet of the plasma reactor via a liquid phase pump.