CN111484618A - Method and device for synthesizing organic silicon compound under assistance of low-temperature plasma electric field - Google Patents

Abstract

The present invention provides a method and device for synthesizing organic silicon compounds by using a low-temperature plasma negative corona discharge electric field to assist, in particular, a method and device for synthesizing organic silicon compounds by using a low-temperature plasma negative corona discharge electric field to assist in treating carbon-containing gas and hydrogen-containing gas with silicon-containing compounds. The method of the present invention utilizes the electric energy generated by the low-temperature negative corona discharge electric field to convert carbon-containing gas and hydrogen-containing gas into gas molecules, atoms, ions and/or free radicals, and obtains organic hydrocarbon compound molecules, ions and/or free radicals through reforming, which are then contacted with silicon-containing compounds to form organic silicon compounds.

Description

Method and device for assisted synthesis of organosilicon compounds by low temperature plasma electric field

technical field

The invention belongs to the technical field of plasma-assisted chemical reactions, and in particular relates to a method and a device for synthesizing organosilicon compounds assisted by a low-temperature plasma electric field; reduction and reforming reactions.

Background technique

With the development of industries that rely on traditional energy, the carbon dioxide produced by the combustion of fossil fuels is increasing day by day, and carbon dioxide has become the main source of risk driving global warming and the greenhouse effect. The impact of carbon dioxide produced by burning fossil fuels on global warming has become a topic of international concern. The control and utilization of carbon dioxide emitted by industry is the main means to deal with the greenhouse effect. Efficient and economical use of carbon dioxide to reduce carbon dioxide emissions has become one of the main contents of sustainable development in the future.

Plasma can be divided into high temperature, hot and low temperature plasma. In low temperature plasma, electrons can have kinetic energy above 5eV, and molecules, radicals and atoms can be in the range from room temperature to hundreds of degrees Celsius. Electrons with sufficient energy can inelastically collide with gas molecules to convert them into active particles such as excited particles, free radicals (or atoms) and ions, activate the reactants, and often make catalytic reactions that are kinetically difficult to carry out. at lower temperature.

At present, low-temperature plasma technology has become a frontier hot topic in the fields of environmental governance and energy development. Researches such as using plasma reaction to purify air and convert carbon dioxide gas have been widely carried out. Low temperature plasma treatment technology can strengthen the decomposition and conversion of carbon dioxide, and promote it to reform with other gases and convert it into many valuable products, which has significant economic advantages and good development prospects.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a low-temperature plasma electric field-assisted method and device for synthesizing organosilicon compounds, especially a low-temperature plasma negative corona discharge electric field-assisted treatment method and device for synthesizing organosilicon compounds from carbon-containing gas and hydrogen-containing gas and silicon-containing compounds The method of the present invention converts carbon-containing gas and hydrogen-containing gas into gas molecules, atoms, ions and/or free radicals by utilizing the electric energy generated by low temperature plasma, and obtains organic hydrocarbon molecules, ions and/or free radicals through reforming , and then contact with a silicon-containing compound to form an organosilicon compound.

Organosilicon compounds refer to compounds that contain Si-C bonds and at least one organic group is directly connected to a silicon atom. It is customary to connect those compounds with organic groups such as oxygen, sulfur, nitrogen and other silicon atoms. called organosilicon compounds. Among them, polysiloxane (containing -Si-O-Si-) composed of silicon-oxygen bond (-Si-O-) as the skeleton is the most numerous, most deeply studied and most widely used type of organosilicon compounds. It accounts for more than 90% of the total consumption.

At present, there are many kinds of silicone products, with more than 10,000 varieties and brands, and more than 4,000 kinds of commonly used ones, which can be roughly divided into three categories: raw materials, intermediates and products. Commonly used silicone intermediates mainly refer to linear or cyclic siloxane oligomers, such as hexamethyldisiloxane (MM), octamethylcyclotetrasiloxane (D4), dimethyl ring Siloxane mixture (DMC) etc.

Silicone has excellent properties, so the application range is very wide. It is not only used as a special material in aviation, cutting-edge technology and military technology sectors, but also in various sectors of the national economy. Metal and paint, medicine and medical, etc. However, the synthetic route of industrial organosilicon compounds is long, and the process control of the monomer synthesis section is strictly controlled. Generally, organic silicon monomers are synthesized by catalytic reactions with raw materials such as methanol, hydrogen chloride, and silicon powder. After the monomers are hydrolyzed, a ring body can be obtained. The preparation process is complicated, the process requirements are high, the production cost is high, and the environmental protection cannot be achieved.

In order to solve the deficiencies in the prior art, the present invention provides a low-temperature plasma negative corona discharge electric field-assisted method for synthesizing organosilicon compounds, the method comprising the steps of: feeding carbon-containing gas and hydrogen-containing gas into a reactor, and the The reactor has a negative corona discharge electric field, and a solution bed containing silicon compounds is placed, the negative corona discharge electric field is a direct current negative corona discharge electric field, or other fields that can provide enough energy to oxidize and decompose the reaction gas molecules into atoms, ions, free radicals, etc. electric field source.

The negative corona discharge electric field of the present invention is not particularly limited, and any plasma source known in the prior art can be used in the present invention. Preferably, the DC negative corona discharge electric field is a high frequency high voltage DC negative corona discharge electric field.

The invention adopts non-thermodynamic equilibrium plasma technology, and gas molecules (carbon-containing gas and hydrogen-containing gas) are excited by electric field energy to form aggregates composed of electrons, ions, atoms, free radicals and molecules. In low-temperature plasma, electrons can have kinetic energy of about 4-6 eV, and electrons with sufficient energy can inelastically collide with gas molecules to convert them into active particles such as excited particles, free radicals (or atoms) and ions to make the reaction biological activation. Corona discharge can use asymmetric electrodes to generate plasma under normal pressure discharge. Dielectric barrier discharge can discharge in the gap of an insulating medium under normal pressure or even higher than atmospheric pressure, resulting in repeated electron-medium collisions, increasing the current density. Strengthen the electric field strength, thereby causing a fast and efficient chemical reaction. The electron velocity inside the plasma generated in this way is very fast, the thermodynamic temperature is high (for example, 11000K), and the gas temperature is close to room temperature, thus forming a non-equilibrium thermodynamic system, resulting in a reaction system not limited by the thermodynamic equilibrium composition law, the maximum Convert all reactants to products as much as possible. On the one hand, the electrons ejected by the electrode have high enough energy to excite, dissociate and reform the reactant molecules, so that the reactant molecules and ions can fully react in a short time and be converted into products; on the other hand, the reacted gas can be maintained Low temperature, or close to room temperature, allows low-temperature gas molecules to effectively obtain the thermodynamic energy required for chemical decomposition or synthesis to react quickly, thereby reducing unnecessary energy consumption for high-temperature and high-pressure processing. It should be pointed out that such an excited reaction system can not only eliminate or reduce the use of catalysts, but also make it possible to avoid the use of high temperature and high pressure process equipment as much as possible.

According to the present invention, the carbon-containing gas and the hydrogen-containing gas are reacted in the negative corona discharge electric field to generate hydrocarbon molecules, ions and/or free radicals, and the generated hydrocarbon molecules, ions and/or free radicals and silicon-containing gas molecules, ions and/or free radicals are generated. The compounds are contacted and reacted, and the silica in the silicon-containing compound is reformed to prepare an organosilicon compound. Preferably, the organosilicon compound is preferably an organosiloxane compound, especially an organosiloxane oligomer C _2n H _6n On Si _n , _where n is an integer, such as n is 4-20, 4-18 or 4 -16. Those skilled in the art can understand that the oligomer synthesized in the present invention is a mixture of various polysiloxanes satisfying the above structural formula.

According to the present invention, various carbon-containing gases such as CH ₄ , CO ₂ , CO and other carbon-containing gases can be used in the negative corona discharge electric field, and various hydrogen-containing gases such as CH ₄ , H ₂ O, H ₂ and other hydrogen-containing gases that are decomposed by a negative corona discharge electric field to produce various active components such as H·, CO ₂ ⁻ , CO ⁻ , CH ₃ · and CO; molecules, atoms, ions and/or free radicals of the gas generated by the decomposition tend to entrain electron movement in a large number of electron groups that are densely erupted, and quickly collide with silicon-containing compounds to generate relatively stable organosilicon compound molecules.

Preferably, mixtures of CH ₄ , CO ₂ , CO and other carbon-containing gases with H ₂ O, H ₂ and other hydrogen-containing gases can be used in the negative corona discharge electric field.

According to the present invention, the source of the carbon-containing gas is not particularly limited, for example, it can come from the gas generated by the combustion device, the carbon source gas containing methane, or the gas generated by the gas generating device, such as natural gas, shale gas, coal seam Gas, biogas, water gas, coke oven gas, flue gas, etc.

According to the present invention, the solution of the silicon-containing compound can be a solution of sodium silicate, lithium silicate, silicic acid, silicon chloride or other silicon-containing compounds, such as water glass, which is a common name for a water-soluble silicate aqueous solution, The chemical formula is R ₂ O·mSiO ₂ , where R ₂ O is an alkali metal oxide, and m is the ratio of the moles of silicon dioxide to the alkali metal oxide; the concentration of silicon in the solution of the silicon-containing compound is not particularly Limited, for example, it can be 0.5-30 wt %, for example, 5-25 wt %, such as 22 wt %.

In an embodiment of the present invention, the carbon-containing gas and the hydrogen-containing gas are passed into the above-mentioned reactor containing the negative corona discharge electric field, and the electrons ejected by the negative corona discharge electric field provide energy to the gas molecules. Electrons are provided to bombard gas molecules in the region of the negative corona discharge electric field, thereby decomposing the gas molecules. Specifically, CO ₂ is used as the carbon source, and H ₂ or H ₂ O is used as the hydrogen source. In the negative corona discharge electric field, the electrodes of the negative corona discharge electric field are corona discharge, and a large number of negative electrons are released to adhere to CO ₂ and H ₂ or H ₂ On the surface of O molecule, gas molecules capture these high-energy electrons to form high-energy electronegative gas ions, such as H ₂ ^- , CO ₂ ^- , CO ^- or H ^- and other anions, as well as CH ₃ · and H · and other free radicals, these anions It will be forced to be re-reduced or reformed into some short-chain hydrocarbons or groups, and the generated short-chain hydrocarbons or groups can further generate free radicals such as CH ₃ · and H · under the action of an electric field. The generated radicals can be contacted with a solution bed of a silicon-containing compound, thereby reacting with a silicon-containing compound (such as sodium silicate or silicon dioxide) to prepare an organosilicon compound.

As an example, when the temperature in the reaction system is 100-110°C (for example, 100-105°C, such as 100-102°C), for example, the temperature of the reaction chamber is 100-110°C (for example, 100-105°C, such as 100-102°C), carbon dioxide gas and water vapor can be mixed into the reactor, and in the negative corona discharge electric field, the gas molecules capture high-energy electrons to form intermediates of negative ions and free radicals, which are further reduced or reformed into For a new substance, the reaction speed is very fast, usually completed within a few seconds, and the instantaneous reaction of its intermediates is difficult to capture and detect. Therefore, the inventors based on the principle of plasma reaction and its function, as well as the products detected by the reaction, speculated that in the negative corona electric field Reactions that take place include but are not limited to the following:

(1)CO ₂ +e ^- =====>CO+1/2O ₂ ^-

(2) CO+H ₂ O+e ^- =====>CO ₂ +H ₂ ^-

(3) CO ₂ ^- +H ₂ O ^- =====>CO+H ₂ ^- +O ₂ +e ^-

(4) H ₂ +2e ^- =====>2H ^- <====>H ₂ ^- +e ^-

(5)CO+2H ₂ ^- <=-=>CH ₄ +1/2O ₂ +2e ^-

(6) CH ₄ +e ^- ==>CH ₃ ·+H · +e ^-

(7)(n+1)H ₂ ^- +nCO====>C _n H _(2n+2) +n/2O ₂ +(n+1)e ^-

In the reaction formula (7), when n is 1, the substantially prepared methane is the same as the reaction formula (5). However, in a negative corona field, there is always a tendency to generate higher boiling, more stable organics, which are retained as end products. However, methane easily captures electrons and further decomposes into CH ₃ · and H ·, or returns to CO and H ₂ ^- through the reverse reaction of reaction formula (5), so in most cases, methane only exists as an intermediate. In the present invention, since there are silicon-containing compounds in the reactor, the CH ₃ · and H · obtained from the decomposition of methane are more likely to have a gas-liquid interface reaction with the liquid-phase silicon-containing compounds, and are captured by the silica in the silicon-containing compounds to generate more stable production. Organosiloxanes:

(8) Na ₂ O·SiO ₂ +H ₂ O====>Na ₂ O+SiO ₂ +H ₂ O

(9) nSiO ₂ +2nCH ₃ ·+H·====>C _2n H _6n O _n Si _n +nH ₂ O

In the above examples, the carbon-containing gas is not limited to carbon dioxide gas, but can also be a gas containing CO ₂ , CO generated by a combustion device or a gas generated by a gas generating device, such as flue gas, automobile exhaust gas, biogas, internal combustion engine exhaust gas, Refinery waste gas, etc.

According to the present invention, the carbon-containing gas, the hydrogen-containing gas and the silicon-containing compound are reformed by the negative corona discharge electric field to obtain a mixed gas. However, under normal operating conditions, the reformed mixed gas can be separated into two phases of gas and liquid after being condensed by the condenser. Among them, the gas phase includes unreacted carbon oxides and hydrocarbons; the liquid phase includes water and organosilicon molecules.

The present invention also provides a low-temperature plasma-assisted device for synthesizing organosilicon compounds, the device comprising a reaction chamber having a plasma region with a negative corona discharge electric field, and a solution bed for placing a silicon-containing compound is arranged under the plasma region .

The present invention also provides a low-temperature plasma-assisted device for synthesizing organosilicon compounds, the device comprising a reaction chamber having a plasma region with a negative corona discharge electric field, and a solution bed for placing a silicon-containing compound is arranged under the plasma region .

According to the present invention, the device has an outer shell, a reaction chamber is arranged in the outer shell, a negative corona discharge electric field is arranged in the reaction chamber, and a solution bed containing silicon compounds is arranged in the lower part of the reaction chamber; Electrodes or metal rods, the negative DC high voltage power supply supplies power to the electrodes or metal rods; the electrodes or metal rods provide high-energy electrons.

Preferably, the housing of the device is grounded.

Preferably, the device further includes a temperature control system for maintaining the temperature inside the device at 100-110°C, for example, 100-105°C, such as 100-102°C; for example, the temperature inside the reaction chamber is 100-110°C (for example, 100-105°C, such as 100-102°C).

Preferably, the device has an air inlet, an air outlet, a liquid inlet and a liquid outlet, wherein the air inlet is arranged at the top of the device; the air outlet is arranged at the bottom of the device, and the air outlet The connected gas outlet pipe extends to the gas region above the solution bed, or the gas outlet is arranged on the side wall of the device and is located in the gas region above the solution bed; the liquid inlet is arranged on the side wall of the device and positioned above the solution bed; The liquid outlet is arranged at the bottom of the solution bed; the air inlet is used to charge the carbon-containing gas and the hydrogen-containing gas into the negative corona discharge electric field of the reaction chamber, and the decomposition products generated in the corona discharge field are then mixed with the solution. The interfacial contact reaction of the silicon-containing compound solution in the bed produces a gas-phase organosilicon compound, the gas outlet and the connected gas outlet pipe are used to remove the gas-phase product containing the gas-phase organosilicon compound, and the liquid inlet is used for the solution of the silicon-containing compound. It is injected into the solution bed, and the liquid outlet is used to discharge the solution residue of the silicon-containing compound.

Preferably, the carbon-containing gas and the hydrogen-containing gas are introduced into the inlet of the reaction chamber from the gas inlet. In order to introduce the gas into the inlet of the reaction chamber, in the cross-sectional direction of the device, a barrier is provided between the outer shell and the inlet of the reaction chamber. plate.

Preferably, a condensation separator communicated with the gas outlet is provided outside the device, and the condensation separator has a liquid outlet and a gas outlet.

Preferably, the electrodes or metal rods are connected to a negative corona discharge electric field source.

Preferably, the reaction chamber is a metal cylindrical reaction chamber or a metal tubular reaction chamber.

Preferably, in the cross-sectional direction of the device, near the exit of the reaction chamber, a baffle is provided between the outer shell and the reaction chamber, and the baffle is used to promote the contact of the gas reformed by the negative corona discharge electric field with the silicon-containing compound, so that The gas-phase product no longer diffuses to the top of the device, and it is easy to remove the gas-phase product from the gas outlet pipe and the gas outlet.

Preferably, an insulating medium thin-layer cylinder can also be placed between the electrode or the metal rod and the outer wall of the metal cylindrical reaction chamber or the metal tubular reaction chamber, and the insulating medium cylinder can be made of materials with different dielectric constants, such as Glass, ceramics, silica gel, etc., the insulating medium thin-layer cylinder and the side wall of the reaction chamber form a gas gap channel, that is, a discharge structure of a dielectric barrier (DBD) (dielectric barrier discharge) is formed, and the metal cylindrical reaction chamber and the metal tube are strengthened. The electric field strength of the reaction chamber is strengthened, thereby strengthening the reaction process.

Preferably, the diameter and number of the metal cylindrical reaction chamber and the metal tubular reaction chamber are not particularly limited, and they can be conventional choices by those skilled in the art. For example, as shown in FIG. 1 , one In the metal cylinder reaction chamber, more than two metal cylinders or metal tubes can also be used to form reaction tubes; when multiple metal cylinders or metal tubes are selected, they have no influence on each other, so there is no need for their arrangement. The special limitation can be reasonably selected according to the size of the device.

Preferably, the number of the metal cylindrical reaction chambers or metal tubular reaction chambers is one or more, and a plurality of metal cylindrical reaction chambers or metal tubular reaction chambers are arranged together to form a cylindrical or tubular column. Tube group.

Preferably, the diameter of the metal cylinder reaction chamber or the metal tube reaction chamber is not particularly limited. Small (such as 30-70mm) metal cylinder or metal tube; the specific selection also needs to be reasonably selected according to the strength of the electric field and the amount of gas to be treated; The magnitude also affects the strength of the electric field within the reaction chamber. For example, when an electrode or a metal rod is set in the center of a metal cylindrical reaction chamber or a metal tubular reaction chamber, if a larger size metal cylinder or metal pipe is used, the internal electric field strength is lower than that of a smaller size metal cylinder or metal pipe. The electric field strength formed inside the metal tube; similarly, the electric field strength can also be adjusted by introducing a medium; adding an insulating medium layer to the electric field with a weak electric field strength will greatly enhance the electric field strength of the electric field; According to the diameter of the metal cylindrical reaction chamber or the metal tubular reaction chamber, the dielectric constant of the insulating medium substance, the voltage of the external power supply and other factors, the personnel reasonably design the electric field strength, and then realize the reformation of the reaction gas.

Preferably, the number of the electrodes is one or more, and the electrodes may be, for example, sawtooth tip electrodes to generate a negative corona discharge electric field around the electrodes.

In some instances, the electrodes are wire or needle shaped elements with a sharp point at the tip of the electrode. The sharp point provides a very high charge area around it. Electrons inside the reaction chamber generate electrons by creating a negative corona discharge electric field at the tip of the electrode. The electrons are generated in the negative corona at the tip of the electrode. These electrons are adsorbed on chemical gas molecules around the tip of the electrode. In the device of the present invention, about 4-6 eV of energy is required to transfer electrons from the surface of the corona electrode for the metal material suitable as the electrode in the device of the negative corona discharge field. The electrodes can be of the following materials: cobalt, gold, nickel, copper, silver, iron, tungsten, or platinum. The present invention does not make any particular limitation on the electrode material, and any material that can form a corona to generate electrons may be used. The electrodes can also be coated with metals, available metals are: cobalt, gold, nickel, rhodium, cesium and platinum. Any metal capable of generating electrons can be used.

Preferably, the shape of the electrodes may be needle-shaped or linear. If the electrode has a sharp point, the potential difference of the gas near the sharp point will be much higher than elsewhere around the electrode. Eventually, the resulting high-potential electronegative ions transfer charge to adjacent low-potential regions, where they recombine to form gas molecules.

Preferably, the principle and arrangement of the metal rods are the same as those of the electrodes. Preferably the metal rods are selected from thin metal rods.

Other sources that provide sufficient energy for electrons to be transferred to the gas can also be used in the present invention. Electronegative gas ions can also be generated by other non-thermal or thermal plasma techniques or ion sources, including high frequency methods such as radio frequency plasma, microwave plasma, inductively coupled plasma and other methods such as electron beam (EB). Any method that produces electronegative gas ions with sufficient energy to react with the gas can be used in the present invention.

The present invention also provides a method for synthesizing organosilicon compounds assisted by a low-temperature plasma negative corona discharge electric field.

The operating conditions of the plasma-assisted gas-phase reaction method and device of the present invention are as follows: it can be operated at different temperatures and pressures, including normal temperature and normal pressure, and the carbon-containing gas and hydrogen-containing gas are fed into the device in gaseous form, and the amount of processing gas Optionally, the power input will increase with the number of multiple discharge metal cylinders or metal tubes in the device and the gas handling capacity. The voltage can be 3,000-300,000 volts, preferably 10,000-200,000 volts, such as 15,000 volts, and the frequency is 15 to 35 kHz, preferably about 20 kHz, 25 kHz or 35 kHz. It should be understood that the above-mentioned conditions are the preferred operating condition ranges of the present invention, but the key to realizing the method and purpose of the present invention lies in the use of plasma corona discharge itself. These operating conditions can be determined by routine experiments, and are not limited to The above specific description.

Preferably, the apparatus can convert carbon- and hydrogen-containing gases into organosilicon compounds, such as siloxanes.

In addition, based on the disclosure of the present invention, other advantages brought by the method and apparatus of the present invention will be apparent to those skilled in the art. Other aspects and advantages of the present invention are described in detail in the detailed description below.

Description of drawings

FIG. 1 is a schematic diagram of a specific structure of the device for plasma-assisted gas-phase reaction according to the present invention.

Detailed ways

It should be understood that these examples are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the contents described in the present invention, various changes or modifications can be made to the present invention, and these equivalent forms also fall within the limited scope of the present invention.

"Gas" as described in this specification and claims refers to those gases in which atoms or molecules are capable of capturing additional electrons to form electronegative ions. Other technical and scientific terms in this specification have their ordinary meanings known in the art.

An example of the present invention using electrodes to provide a negative corona discharge electric field is described below. It should be understood that the present invention is not so limited, and electrodes that are capable of generating a plasma discharge at a sufficiently high energy state to generate electrons can also be used in the present invention.

FIG. 1 shows a schematic diagram of a specific structure of the apparatus for plasma-assisted gas-phase reaction according to the present invention. In corona discharge, the reactive gas is passed through a high-frequency high-voltage negative DC corona discharge electric field, where it is reduced and converted into products.

In an embodiment of the present invention, the negative corona discharge electric field is a high frequency high voltage direct current negative corona discharge electric field. The high voltage is, for example, 15,000 volts. The high frequency is a high frequency voltage, eg 25kHz. Electrodes or metal rods are arranged in the electric field region of high frequency high voltage direct current negative corona discharge, which can provide high enough energy, eg 5 eV, to convert the gas molecules. Device 117 has a housing that may be made of carbon steel, stainless steel, or other suitable material.

A cylindrical or tubular reaction chamber 111 is provided within the apparatus 117 formed by the housing, wherein the material of the cylindrical or tubular reaction chamber may be made of stainless steel, carbon steel or copper and other metals. An electrode 112 is arranged in the center of the cylindrical or tubular reaction chamber 111, and the electrode is a needle-shaped or sawtooth rod electrode with a tip. A high frequency high voltage direct current negative voltage is applied to the electrodes 112 in the electric field through the electrode distribution plate 123 to form a high frequency high voltage direct current negative corona discharge electric field. The voltage (intensity) should be selected so that the gas delivered into the device 117 through the gas inlet 110 at the top of the device 117 can be highly ionized in the metal cylinder or metal tubular reaction chamber 111 .

The insulating dielectric cylinder 122 is arranged between the electrode 112 and the outer wall of the cylinder or the tubular reaction chamber 111, which can form a dielectric barrier discharge (DBD) in the electric field, which can provide a narrow collision reaction zone to strengthen the decomposition of all molecules into free radicals or ions, thereby forming product molecules, enhancing the electric field strength of the plasma-assisted reaction process. The material of the insulating medium cylinder 122 is, for example, glass, ceramics, polytetrafluoroethylene sheet, and the like.

The electrode material of the electrode 112 can be nickel, cobalt, iron, steel, tungsten, nickel, copper, silver, iron, carbon or platinum, or any other material that can be used for the electrode and generate a corona around the electrode to generate electrons. The electrodes can also be coated with metals, available metals are: cobalt, nickel, rhodium, cesium and platinum. Any metal capable of generating electrons can be used.

During operation, when the electrode 112 is connected to the electric field source through the electrode distribution plate 123, a discharge is formed at the tip of the electrode 112, and then a corona field discharge is formed, and the high-energy electrons hit the gas molecules, which can stimulate reduction and reformation reactions.

The high voltage electricity is sent to the electrode 112 through the electrode distribution plate 123 for discharge. A partition plate 121 is provided on the side close to the outlet of the cylindrical or tubular reaction chamber 111, and the partition plate 121 divides the device into upper and lower spaces, and the device shell is connected to the ground.

The carbon-containing gas and the hydrogen-containing gas are fed into the negative corona discharge electric field within the device 117 through the air inlet 110 at the top of the device 117 . Some gas molecules can be oxidized and reformed by receiving the discharged electrons in the negative corona discharge electric field. In the negative corona discharge electric field, gas molecules and ions can be reduced and transformed. After these gas molecules and ions leave the negative corona discharge electric field, they come into contact with the solution bed containing silicon compounds and react to generate organic silicon molecules. The liquid of the silicon compound can be discharged through port 125 , and the gas containing unreacted hydrocarbons and oxygen can be discharged through port 124 .

The silicon compound-containing solution bed 115 at the bottom of the device 117 stores a silicon compound solution, and the silicon compound solution can be added through a liquid inlet 118 provided on the side wall of the device. After the reaction is completed, the remaining or waste silicon compound solution is discharged through the liquid outlet 120 at the bottom of the device.

The present invention uses carbon dioxide and water vapor as the raw material gas, the temperature in the reaction chamber is 100-102° C., and is transformed by the above-mentioned device, and the liquid discharged from the above-mentioned port 125 is detected by the Guangzhou Analysis and Testing Center in China. The liquid obtained by qualitative analysis includes but not limited to The following products, the results are shown in the following table:

It can be known from the detection results shown in the above table that the organosilicon compound can be prepared by using the device and method of the present application.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A method for synthesizing an organic silicon compound by assistance of a low-temperature plasma negative corona discharge electric field, wherein the method comprises the following steps: introducing a carbon-containing gas and a hydrogen-containing gas into a reactor, wherein the reactor is provided with a negative corona discharge electric field and a solution bed for placing a silicon-containing compound, and the negative corona discharge electric field is a direct current negative corona discharge electric field or other electric field sources capable of providing enough energy to oxidize and decompose reaction gas molecules into atoms, ions, free radicals and the like.

2. The method of claim 1, wherein the direct current negative corona discharge electric field is a high frequency, high voltage direct current negative corona discharge electric field.

3. The method according to claim 1 or 2, wherein the carbon-containing gas and the hydrogen-containing gas react in the negative corona discharge electric field to generate hydrocarbon molecules, ions and/or radicals, the generated hydrocarbon molecules, ions and/or radicals contact with the silicon-containing compound to react, and the silicon dioxide in the silicon-containing compound is reformed to prepare the organosilicon compound.

Preferably, the organosilicon compound is preferably an organosiloxane compound, such as organosiloxane oligomer C_2nH_6nO_nSi_nWherein n is an integer.

4. A method according to any of claims 1-3, wherein various carbon-containing gases, such as CH, can be used in the negative corona discharge field₄、CO₂CO and other carbon-containing gases, various hydrogen-containing gases, such as CH, may be used in the negative corona discharge field₄、H₂O、H₂And other hydrogen-containing gases which are decomposed by a negative corona discharge electric field to produce various active components, such as O₃、H^-、H、CH₃And CO.

Preferably, CH may be used in a negative corona discharge electric field₄、CO₂CO and other carbon-containing gases with H₂O、H₂And a mixed gas of gaseous hydrogen-containing gas.

Preferably, the carbonaceous gas is derived from a gas produced by a combustion device, a carbon source gas containing methane, or a gas produced by a gas generation device, such as natural gas, shale gas, coal bed gas, biogas, water gas, coke oven gas, flue gas, and the like.

Preferably, the solution of the silicon-containing compound may be a solution of sodium silicate, lithium silicate, silicic acid, silicon chloride or other silicon-containing compounds.

5. The method according to any one of claims 1 to 4, wherein CO is used₂As a carbon source, H₂Or H₂O is used as hydrogen source, corona discharge is carried out on the electrode of the negative corona discharge electric field in the negative corona discharge electric field area, and a large number of negative electrons are released to be adhered to CO₂And H₂Or H₂The gas molecules trap these high energy electrons to form high energy electronegative gas ions, such as H₂ ^-，CO₂ ^-，CO^-Or H^-Plasma anion, and CH₃And H, etc., the negative ions are forced to be reduced or reformed into short-chain hydrocarbons or radicals, and the generated short-chain hydrocarbons or radicals can be subjected to the action of an electric fieldFurther generation of e.g. CH₃And H.and the like. The generated radicals may be contacted with a bed of a solution of a silicon-containing compound to react with the silicon-containing compound (e.g., sodium silicate or silica) to produce an organosilicon compound.

6. The method according to any one of claims 1 to 5, wherein the carbon-containing gas, the hydrogen-containing gas and the silicon-containing compound are reformed by a negative corona discharge electric field to obtain a mixed gas, and the reformed mixed gas can be separated into a gas phase and a liquid phase after being condensed by a condenser; wherein the gas phase comprises unreacted carbon oxides and hydrocarbons; the liquid phase includes water and silicone molecules.

7. An apparatus for low temperature plasma-assisted synthesis of organosilicon compounds, wherein the apparatus comprises a reaction chamber having a plasma region with a negative corona discharge electric field, below which is disposed a solution bed in which a silicon-containing compound is disposed.

8. The apparatus of claim 7, wherein the apparatus has a housing, a reaction chamber is disposed within the housing, a negative corona discharge electric field is disposed within the reaction chamber, and a solution bed in which the silicon-containing compound is disposed below the reaction chamber; an electrode or a metal rod is arranged in the center of the negative corona discharge electric field, and a negative direct-current high-voltage power supply supplies power to the electrode or the metal rod; the electrodes or metal rods provide energetic electrons.

Preferably, the electrode or metal rod is connected to a source of negative corona discharge electric field.

Preferably, the reaction chamber is a metal cylinder type reaction chamber or a metal tube type reaction chamber.

Preferably, a baffle is provided between the housing and the reaction chamber in the cross-sectional direction of the device, at a position near the outlet of the reaction chamber.

Preferably, a baffle is provided between the housing and the inlet of the reaction chamber in the cross-sectional direction of the device.

Preferably, an insulating dielectric thin-layer cylinder can be further placed between the electrode or the metal rod and the outer wall of the metal cylindrical reaction chamber or the metal tubular reaction chamber, the insulating dielectric thin-layer cylinder can be made of materials with different dielectric constants, such as glass, ceramics, silica gel and the like, and the insulating dielectric thin-layer cylinder and the side wall of the reaction chamber form a gas crack channel, namely a dielectric barrier discharge structure.

Preferably, the number of the metal cylindrical reaction chambers or the metal tubular reaction chambers is one or more, and a plurality of the metal cylindrical reaction chambers or the metal tubular reaction chambers are arranged together to form a cylinder or tubular array tube group.

9. The apparatus of claim 7 or 8, wherein the apparatus has a gas inlet, a gas outlet, a liquid inlet and a liquid outlet, wherein the gas inlet is disposed at a top of the apparatus; the gas outlet is arranged at the bottom of the device, and a gas outlet pipe connected with the gas outlet extends to a gas area above the solution bed, or the gas outlet is arranged on the side wall of the device and is positioned in the gas area above the solution bed; the liquid inlet is arranged on the side wall of the device and is positioned above the solution bed; the liquid outlet is arranged at the bottom of the solution bed.

Preferably, a condensation separator is arranged outside the device and communicated with the air outlet, and the condensation separator is provided with a liquid outlet and a gas outlet.

10. A method for synthesizing an organic silicon compound by low-temperature plasma negative corona discharge electric field assistance, which is based on the apparatus of any one of claims 7 to 9, and which further comprises the method for synthesizing an organic silicon compound by low-temperature plasma negative corona discharge electric field assistance of any one of claims 1 to 6.

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