KR20100121388A - Vertical reactor for obtaining silane and method for continuous obtaining silane using the same - Google Patents

Abstract

PURPOSE: In one reactor the stoichiometric flow is guaranteed. It can switch into the mono silane gas by altogether reacting the silicon halides, the continuous recovering method of silane for manufacture vertical reactor and silane using the same. CONSTITUTION: The silane for manufacture vertical reactor. With the first raw material of the liquid including the metal hydride. The second raw material of the weather including the silicon halides. The reactive part(110) including a plurality of active zones reacting. The first inlet which is formed in the upper one side of the reactive part, and flows in the first raw material as the reactive part(120).

Description

Vertical reactor for obtaining silane and method for continuous obtaining silane using the same}

The present invention relates to a vertical reactor for producing silane and a continuous recovery method of silane using the same.

In recent years, the production of monosilane has significant implications for the production of "solar grade" silicon for the production of semiconductor silicon, thin film silicon layers and photovoltaic devices.

In general, metallurgical silicon (MGS) is the first raw material used in semiconductor silicon production. The recovery of the semiconductor silicon from the metal silicon requires a large number of steps, which results in high energy loss.

Specifically, first, the metal silicon is converted into volatile silicon compounds, and the volatile silicon compounds are subjected to various steps of purification, and then the purified volatile silicon compounds are recovered into semiconductor silicon.

Meanwhile, in some industries, a halogen compound of silicon such as silicon tetrahalide is produced in large quantities as a byproduct in the production of titanium, magnesium, and trichlorosilane. In addition, fertilizer production generates a large amount of silicon tetrafluoride, which, if discarded as is, can cause great environmental problems, but when used in the recovery process of silicon, It can be usefully used as a cheap raw material.

Thus, attention has been paid to the process of converting silicon halide compounds such as silicon tetrafluoride into valuable products such as monosilane and alkali metal aluminum fluoride.

The process of recovering monosilane using silicon halide may be performed by, for example, Scheme 1 below.

NaAlH ₄ + SiF ₄ → NaAlF ₄ + SiH ₄

Here, the NaAlF ₄ compound generally does not appear as a single stoichiometric compound in the reaction product, but is produced together with Na ₅ Al ₃ F ₁₄ ㆍ AlF ₃ , AlF ₃ , NaF and other compounds. do.

Initial raw materials typically contain a mixture of various halides such as chloride, fluoride, free hydrogen halide, element impurities, moisture or oxygen in the silicon halide compound. Compound, etc.) and impurities in the metal hydride (eg, NaAlH ₂ Et ₂ ). Accordingly, reaction products may include by-products such as hydrocarbons, hydrogen, and aluminum metal.

All such ancillary processes are subject to the difficulty of selecting and controlling the reaction flow to ensure stoichiometric reactions.

Thus, if the process is not properly controlled, the large amount of unreacted silicon halides may limit the recovery of monosilane or contaminate the monosilane, thereby making the purification and separation process of the mixture more difficult and containing hydrogen. The generation of metal halides not only significantly increased the risk of treatment, but also made it difficult to restore and use them.

Accordingly, various methods have been developed to solve this technical problem.

US Pat. No. 4,632,816 discloses a method for recovering monosilane from excess metal hydride contained in one reactor.

However, according to the above method, the reaction apparatus may be rapidly contaminated due to contamination by the metal halide containing hydrogen and aluminum metal produced as a by-product thereof, and thus, the production and recovery function of the monosilane is deteriorated. have.

In addition, U.S. Patent No. 4,847,061 discloses a method for recovering monosilane in two reactors formed in the opposite direction to the movement of the reaction stream to reduce contamination by hydrogen containing metal halides. However, this type of solution also has a problem that it does not completely solve the problem of contamination due to the metal halide containing hydrogen.

On the other hand, US Patent No. 5,075,092 discloses a method for the continuous recovery of monosilane through a prototype consisting of three devices. The two reactors flow in the opposite direction to the reaction flow for ideal mixing, and the third reactor is designed to react in contact with several chemical reaction processes in the gas phase. This allows the third reactor to ideally mix the two processes and serve to separate the gas and liquid phases.

More specifically, the method for the continuous recovery of the monosilane according to the conventional literature will first be described. First, silicon halide is fed to the first reactor, and reacted with the remainder of the metal hydride to convert almost all of the silicon halide to monosilane. After this, a mixture comprising unreacted silicon halide and monosilane is fed to the second reactor. The metal hydride is fed to the second reactor, reacted with the monosilane supplied from the first reactor, and then transferred to the first reactor for final release. In addition, the stoichiometric ratio of the feed is adjusted by minimizing heat release inside the second reactor.

According to this method, the stoichiometric ratio of the reactants approaches an approximation, and in particular, it is possible to prevent the metal halides which do not react with the metal hydrides from leaking in a contaminated state.

However, according to the above method, since the use of two reactors requires the transport of sludge containing metal hydride to the pump, the hydride may be destroyed due to the division of aluminum on the surface of the device, thereby There is a problem that by increasing the consumption can shorten the life of the device and make the operation difficult.

Furthermore, the second reactor, in which excessive reaction of silicon halides and metal hydrides (there is no excess because both materials are used for almost 100% bonding), is a controlled reactor that stoichiometrically controls the feed of the mixing reactor and raw material reactants. Depending on the reaction characteristics in the mixing reactor, there may be raw materials remaining in the reaction product which are relatively small but not always able to react. Thus, an ideal mixing reactor equipped with a mechanical mixing device is provided. There is a problem in that it must be used.

That is, when using such a mixing reactor as the main apparatus, it may be difficult to expand the reactor to increase the production power of the monosilane, there was a problem that it is difficult to recover the monosilane in large quantities.

The present invention was created in order to solve the above problems, and an object of the present invention is to perform a stoichiometric reaction for producing silane using silicon halide with only one reactor, and includes a reaction section including a plurality of reaction zones. At the stop, the silicon halide flowing from the bottom is reacted with the metal hydride flowing from the top to produce monosilane and metal halides, and the monosilane and metal halides generated are continuously separated and recovered to the upper and lower outlets, respectively. It is to provide a vertical reactor for producing silane and a continuous recovery method of silane using the same.

According to an aspect of the present invention, there is provided a device comprising: a reaction unit including a plurality of reaction zones in which a first raw material in a liquid phase including a metal hydride and a second raw material in a gas phase including silicon halides are reacted; A first inlet formed on an upper side of the reaction part and introducing a first raw material into the reaction part; A second inlet formed on one side of the lower portion of the reaction part and introducing a second raw material into the reaction part; A first outlet formed at an upper end of the reaction part and discharging silane gas generated in the reaction part; And a second outlet formed at a lower end of the reaction part and discharging the liquid metal halide generated in the reaction part.

In another aspect, the present invention provides a continuous recovery method of silane to recover the silane using a vertical reactor for producing silane according to the present invention.

According to the present invention, it is possible to provide a vertical reactor for producing silane capable of producing silane continuously by smoothing hydrogenation of silicon halide and a method for continuously recovering silane using the same. In addition, according to the present invention, in one reactor, the stoichiometric flow can be ensured, so that all of the silicon halides can be converted into monosilane gas, thereby easily separating and recovering the produced monosilane gas. In addition, the metal hydride remaining without reaction can be reused in the reaction with the halogenated silane through reflow, thereby reducing the waste of raw materials.

In addition, since the process is performed using only one reactor, the process can be simplified, the connection part can be shortened, the loss due to the movement of the initial reaction product can be reduced, and the derived reaction product can be efficiently used. As a result, production costs can be greatly reduced.

The present invention comprises: a reaction part including a plurality of reaction zones in which a first raw material in a liquid phase including a metal hydride and a second raw material in a gas phase including silicon halides are reacted; A first inlet formed on one side of the upper part of the reaction part to introduce a first raw material into the reaction part; A second inlet formed on one side of the lower portion of the reaction part and introducing a second raw material into the reaction part; A first outlet formed at an upper end of the reaction part and discharging silane gas generated in the reaction part; And a second discharge port formed at a lower end of the reaction unit and discharging the liquid metal halide produced in the reaction unit.

Hereinafter, a vertical reactor for producing silane according to the present invention will be described in more detail.

Referring to FIG. 1, a vertical reactor 100 for producing silane according to an embodiment of the present invention may include a reaction part including a plurality of reaction zones in which a liquid metal hydride and a gaseous silicon halide react as described above. 110); A first inlet 120 formed on one side of the upper part of the reaction part 110 to introduce metal hydride into the reaction part 110; A second inlet 130 formed at one lower side of the reaction part 110 to introduce silicon halide into the reaction part 110; A first outlet 140 formed at an upper end of the reaction part 110 to discharge silane gas generated through the reaction; And a second outlet 150 formed at a lower end of the reaction unit 110 to discharge the metal halide of the liquid phase generated through the reaction.

That is, the silane manufacturing vertical reactor 100 according to an embodiment of the present invention introduces a liquid metal hydride into the upper portion of the reaction unit 110 through the first inlet 120, and the second inlet 130. The gaseous silicon halide is introduced into the lower portion of the reaction unit 110 through the.

That is, as the metal hydride in the liquid phase introduced into the upper and lower portions and the silicon halide in the gas phase are brought into contact with each other, a reaction occurs in a plurality of reaction zones provided in the reaction unit 110. Since both of the silane gas and the liquid metal halides generated according to the stop portion of the first and second reaction holes 110 are formed at the upper end of the reaction unit 110 and the second outlet formed at the lower end of the reaction unit 110, respectively. Discharge through 150.

As used herein, the term "vertical reactor" refers to a reactor in which a reaction part is formed along a vertical direction, and the shape and shape thereof are not particularly limited. For example, the vertical reactor may have a relatively long height compared to the diameter. The branch may be a column-type reactor.

That is, in the vertical reactor for producing silane according to the present invention, a first inlet and a second inlet formed of a liquid metal hydride and a gaseous silicon halide on one upper side and one lower side, respectively, in one reactor. All reactions are carried out in the reaction zone formed in the middle portion of the reaction unit of the plurality of reaction zones, so as to separate the silane gas and the liquid metal halide obtained therefrom at the top and the bottom of the reaction unit, respectively. Discharge through the discharge port and the second discharge port.

In addition, the reaction zone is not particularly limited, but may include, for example, a reaction rack formed so that the first liquid of the introduced liquid phase reacts for a predetermined time and then overflows.

Here, the reaction shelf is a contact-type device to prevent the accumulation of solids, made of a kind of dish or shelf formed so that the liquid compound (ex. NaAlH ₄ solution) and the gas phase compound (ex. SiF ₄ ) can react by contact. Can be.

More specifically, for example, the metal halide (ex. NaAlF ₄ ) generated through the reaction with the liquid metal hydride (ex. NaAlH ₄ ) may have a slurry form, and the metal halide in the slurry form may not accumulate. It may be configured to flow over the outside of the reaction shelf so as not to.

In addition, the reaction unit may further include a liquid transport device, thereby allowing a smoother flow.

Meanwhile, as described above, the reaction unit includes a plurality of reaction zones for reacting the first raw material and the second raw material to generate the high value-added monosilane and the metal halide generated as all the reactions are performed at the stop of the reaction part. If the separation can be recovered, and the number of stages is not particularly limited, for example, the reaction zone may be formed in three to 30 stages in the vertical direction from the top to the bottom.

That is, as described above, the reaction part includes a plurality of reaction zones so that the first raw material of the liquid phase and the second raw material of the gaseous phase respectively introduced into the upper part and the lower part of the reaction part can perform the reaction at various heights along the vertical direction. I can regulate it.

Here, when the reaction zone is formed in less than three stages, it may be difficult to control the reaction so that the reaction occurs mainly at the stop of the reaction portion, and if it exceeds 30 stages, there is a fear that the efficiency is reduced due to the excess equipment. .

In addition, the reaction unit may further include a stirring device for mixing the first raw material and the second raw material introduced.

 The stirring device serves to uniformly mix the first raw material and the second raw material so that sufficient contact can be made between the reacting raw materials, and the number thereof is not particularly limited. It can be installed separately for each reaction zone so that it can be mixed well, and one stirring device can be installed to operate simultaneously with blades for each reaction zone.

In addition, the form of the stirring device is not particularly limited, but, for example, the first raw material and the second inside of the reaction unit are attached to the stirring shaft and the stirring shaft formed along the vertical direction from the upper part to the lower part of the reaction part. It may be to include at least one blade for mixing the raw materials. That is, in the stirring device as described above, as the stirring shaft rotates, the blade attached to the stirring shaft rotates along the stirring shaft to uniformly mix the raw materials in the reaction unit, and the blade may be provided in each reaction zone. have.

On the other hand, the vertical reactor for producing silane according to the present invention may further include a heat sensing unit for measuring the temperature inside the reaction unit.

The heat sensing unit measures a temperature to detect a temperature inside the reaction unit so as to predict where the main reaction occurs in the reaction unit. Accordingly, when the reaction unit includes at least two reaction zones, each reaction By measuring the heat of reaction in the zone, if the main reaction occurs in the reaction zone formed in the upper and lower portions of the reaction section, it can be induced to occur in the stop of the reaction section.

That is, when the main reaction zone (the reaction zone with the highest heat of reaction) formed according to the heat of reaction measured through the heat sensing unit is formed at the top or the bottom of the reaction unit, the reaction is not normally controlled. By controlling the stoichiometric relationship between the reactants contained in the raw material and the second raw material, the heat of reaction can be controlled to appear high at the stop of the reaction part.

For example, when the temperature of the inside of the reaction unit is measured by the heat sensing unit, when the heat of reaction in the reaction zone formed at the upper or lower portion of the reaction unit appears to be high, it flows into the first inlet or the second inlet to control this. Inflow of the first raw material and / or the second raw material can be controlled.

That is, when the main reaction appears in the reaction zone formed at the bottom of the reaction section, it means that the metal hydride is oversupplied and the main reaction occurs in the reaction zone on the lower side, thereby reducing the inflow of metal hydride or reducing the inflow of silicon halide. If the main reaction occurs in the reaction zone formed at the top of the reaction section, it means that the silicon halide is oversupplied, so that the inflow of silicon halide or the inflow of metal hydride can be increased.

Meanwhile, the vertical reactor for producing silane according to the present invention may further include a heat exchanger for absorbing heat in the reaction zone or supplying heat into the reaction zone according to the temperature of the reaction zone measured by the heat sensing unit.

The heat exchanger serves to adjust the temperature in each reaction zone according to the temperature measured from the heat sensing unit. As described above, the heat exchanger functions as a heat exchanger by adjusting the amount of raw material introduced according to the measured reaction heat. It may be possible, however, when the heat exchanger is further included, separate heating and cooling means may be used to adjust the temperature of the reaction zone.

The heat exchanger may include all of heat exchangers that may be commonly used in the art, and may include, for example, a heating device for supplying heat to the reaction part and a cooling device for absorbing heat from the reaction part.

Meanwhile, the vertical reactor for producing silane according to the present invention may further include a third inlet formed on one side of the lower part of the reaction part to re-introduce the liquid metal halide discharged through the second outlet into the reaction part. When the vertical reactor for producing silane according to the present invention includes the third inlet, the residue remaining in the liquid phase may be reintroduced through the third inlet so that the slurry remaining in the lower portion of the reaction portion is stagnant to cause precipitation. The flow can be smoothed to prevent it.

Furthermore, it may further include a pump unit for transferring the residue to the first inlet or the third inlet so that the liquid metal halide discharged through the second outlet to the reaction unit.

That is, when the liquid metal halide discharged to the second outlet is separated with high purity, it may be discharged as it is and used separately.If unreacted metal hydride is present, it is transferred to the first inlet as needed in the process. It may be re-introduced, and by re-introducing through the third inlet, it is possible to reduce the loss of the raw material by providing a flow so that the unreacted metal hydride in the lower portion of the reaction unit can participate in the reaction without precipitation.

Meanwhile, the material of the vertical reactor for producing silane according to the present invention is not particularly limited, but may be made of a material commonly used in the art, but may be made of a material such as carbon steel.

In addition, the vertical reactor for producing silane according to the present invention does not need to move gas and liquid to another device because the reaction is performed in one device, so that a compressor or a pump may not be used.

In addition, the present invention relates to a continuous recovery method of silane for recovering the silane gas obtained by using the vertical reactor for producing silane according to the present invention, specifically, alkali metal hydride and / or aluminum hydride, and the like. A series of silanes that separate and recover high-purity halogenated products and monosilanes from the same metal hydrides and silicon halides such as silicon tetrafluoride, trichlorosilane, and dichlorosilane. It relates to a recovery method.

According to the continuous recovery method of silane according to the present invention, since the silane and metal halides can be generated and recovered continuously by using a vertical reactor for producing silane as described above, it is suitable for mass production. This is not mixed, and separately discharged to the upper end and the lower end of the reaction unit, it is possible to recover a high purity monosilane and metal halides.

Continuous recovery method of the silane according to the present invention, as described above, if the silane can be continuously produced using the vertical reactor for producing a silane according to the present invention, the specific kind is not particularly limited, for example, reaction A first step of introducing a liquid first raw material including a metal hydride into an upper portion of the reaction part through a first inlet formed on one side of the upper part; A second step of introducing a second raw material of a gaseous phase including silicon halide into the lower portion of the reaction portion through a second inlet formed at one lower portion of the reaction portion; A third step of reacting the first raw material and the second raw material introduced into the reaction unit in the first step and the second step; And a fourth step of separating and discharging the silane gas and the liquid metal halide formed in the third step.

However, the first step and the second step are not specified in a time-series order, but may be performed simultaneously, respectively, and the time-series propagation relationship is not greatly limited.

Hereinafter, the steps described in more detail, the first step is a step of introducing the first liquid in the liquid phase containing the metal hydride through the first inlet to the upper portion of the reaction unit. That is, the liquid metal hydride is introduced into the reaction part through the first inlet formed in the upper part of the reaction part to react with the gaseous silicon halide introduced in the second step to be described later.

Although the type of the metal hydride used in the first step is not particularly limited, for example, it may be a compound represented by the following formula (1) or (2).

AH ₄

In Formula 1, A is lithium, sodium or potassium,

AAlH ₄

In Formula 2, A is lithium, sodium or potassium.

More specifically, the liquid metal hydride may include an alkali metal hydride (ex. NaH or LiH), or an aluminum hydride (LiAlH ₄ , NaAlH ₄ or KAlH ₄ ).

Meanwhile, in the first step, the liquid first raw material may include one or more solvents selected from ethers or cyclic ethers, and more specifically, the solvent may be diethylene glycol dimethyl ether, ethylene glycol dimethyl ether, 1,4-dioxane. , Butyl ether and derivatives thereof.

In addition, the solvent may further include a hydrocarbon. The type of the hydrocarbon is not particularly limited, and may include all hydrocarbons of various forms that may be used in admixture with ethers or cyclic ethers, but for example, one selected from the group consisting of toluene, toluene derivatives, and other hydrocarbon compounds. The above may be included, and more specifically, toluene, xylene, hexane, heptane and the like may be used.

As such, by dissolving the metal hydride in the above-described solvent, it is possible to prevent the clogging of the solid metal halide in the reactor, and since the solid metal halide is not dissolved in the solvent, it is easily used. Can be discharged separately. In addition, toluene or other hydrocarbon solvents become part of the reaction mixture due to the synthesis of sodium aluminum hydride, and do not necessarily have to be separated, the concentration is determined by the synthesis conditions of sodium aluminum hydride, in the present invention It does not affect the recovery process of the monosilanes described.

In addition, any known method may be used to recover the solvent evaporating from the monosilane, for example using a dephlegmator or cold to reduce the loss of the solvent into the gaseous reaction product. The cooled sodium aluminum hydride solution can be fed to the top of the device.

On the other hand, the second step is a step of introducing the second raw material of the gaseous phase containing silicon halide into the reaction unit through the second inlet provided on the lower side of the reaction unit.

In the second step, silicon halide is also not particularly limited in kind, for example, may be a compound represented by the following formula (3) or (4).

SiX _n Y _{4 -n}

In Formula 3, X and Y are each independently fluorine, chlorine or bromine, n is an integer of 1 to 4,

H _n SiX _{4 -n}

In Formula 4, X is fluorine, chlorine or bromine, n is an integer of 1 to 3.

More specific examples of the silicon halide may be SiF ₄ , SiCl ₄ , SiBr ₄ , SiI ₄ , and the like, and various halogens, such as SiBr ₂ Cl ₂ , SiF ₂ Cl ₂ , SiFCl ₃ , EtSiF ₃ , Et ₂ SiF ₂ , etc. Silicon halides in which organohalogenated silicon is mixed may be used.

Further, in the present invention, the third step is a step of reacting the first raw material and the second raw material introduced into the reaction unit in the first step and the second step. As described above, in the third step, the reaction takes place mainly at the stop of the reaction section, and the monosilane and metal halides thus produced can be separately discharged to the top and the bottom, respectively.

The reaction contact time between the gaseous silicon halide in the reaction zone and the liquid metal hydride in each reaction zone prevents an increase in heat release in one reactor, and according to the object of the present invention, the main reaction is performed at the stop of the reaction section for high purity. The monosilane and the metal halide may be controlled within an appropriate time range so as to separate and discharge, and are not particularly limited.

On the other hand, the pressure of the reaction unit in the third step is also not particularly limited, for example, can be carried out at atmospheric pressure (atmospheric pressure) or more, for example, a pressure of 1 atm (absolute) to 10 atm (absolute) It may be carried out under the conditions, specifically, it can be carried out under pressure conditions of 1.2 atm (absolute) to 1.4 atm (absolute).

Further, in the third step, the reaction may be carried out, for example, at a temperature of 10 ° C. to 110 ° C., specifically, in the case where the liquid metal hydride of the first step includes diethylene glycol dimethyl ether, 30 It may be carried out at a temperature of ℃ to 70 ℃, more specifically, the pressure of the reaction unit may be carried out under the conditions of 1.2 atm (absolute), the temperature is 80 ℃ to 110 ℃.

Here, since the viscosity of the solvent is increased when the reaction temperature is less than 10 ℃, when mixing the raw materials through the stirring device, the load may be applied to the stirring device, when the reaction temperature exceeds 110 ℃ silicon halide to the solvent It may melt and react and vaporize as it is.

On the other hand, in the continuous recovery method of silane according to the present invention, the third step, the step of measuring the temperature of the reaction unit; And it may further comprise the step (2) of controlling the inflow of the metal hydride and silicon halide flowing into the reaction unit in accordance with the temperature measured in the step (1).

In addition, the third step, the step (A) of measuring the temperature of the reaction unit; And supplying or recovering heat to the reaction part according to the measured temperature.

That is, the effects that can be obtained by controlling the inflow amount of the metal hydride and silicon halide flowing into the reaction part or supplying or recovering heat supplied to the reaction part by measuring the temperature inside the reaction part are as described above.

Here, as an example of the cooling means for recovering heat from the reaction portion, it is possible to cool the reaction portion using an external cooling flow (ex. In the form of rotating water), more specifically, the cooling means for each reaction zone The temperature in the reaction zone can be adjusted so that the heat of reaction does not appear high at the top or bottom of the reaction section.

In addition, the fourth step in the present invention, is the step of separating and discharging the silane gas and the liquid metal halide generated in the third step.

That is, as described above, when the silane gas and the liquid metal halide are generated through the third step, the gaseous silane is discharged through the upper part of the reaction part, and the liquid metal halide flowing down to the lower part of the reaction part reacts. Can be discharged through the bottom of the unit.

The continuous recovery method of the silane according to the present invention may further include the step of re-introducing the liquid metal halide discharged to the bottom of the reaction section to the top or bottom of the reaction section.

That is, if necessary, the reaction may be performed by reflowing the liquid metal halide in which the unreacted metal hydride remains to the upper part of the reaction part, or flowing into the lower part of the reaction part to facilitate the flow of the lower part of the reaction part. It may also provide flowability.

Hereinafter, referring to FIG. 1, the continuous recovery method of silane using the vertical reactor 100 for producing silane according to an example of the present invention will be described in more detail. Inflow to the lower one side of (110) (①), it can be introduced into the upper side of the upper portion of the liquid metal hydride through the first inlet (120) (②).

Subsequently, when the gaseous silicon halide and the liquid metal hydride are reacted in the reaction unit 110 to generate a monosilane gas and a liquid metal halide, the monosilane gas is formed on the upper portion of the reaction unit 110. It can be discharged through the first outlet 140 (③).

In addition, after discharging the liquid metal halide to the second outlet 150 formed at the lower end of the reaction unit 110 by using the pump unit 170, it is recovered or to the outside of the reactor for the preparation of a new process thereafter. It may leak (④). In addition, the residue of the liquid phase may be re-introduced through the third inlet 160 to facilitate the flow of the lower portion of the reaction unit (⑤), and the metal hydride that has not reacted in the residue may be used according to process requirements. By transferring the metal hydride to the upper portion of the reaction unit 110 so that the reaction can be carried out again (⑥).

According to this, only the metal halide may be filled in the lower portion of the reaction unit 110 without impurities such as metal hydride or monosilane.

In addition, silicon halides such as tetrafluoro silane can react with the liquid metal hydride while uniformly passing through all the reaction zones from the lower part of the reaction part to the upper part. The monosilane gas may be discharged through the first outlet formed at the top of the reaction unit.

That is, the monosilane discharged accordingly is a high-purity monosilane containing almost no impurities, and can be usefully used, and an extremely small amount of impurities contained in the monosilane gas can be purified through an additional purification process if necessary. have.

In addition, the metal hydride (ex. NaAlH ₄ ) solution dissolved in the hydrocarbon or ether solvent passes through all the reaction zones uniformly through the first inlet formed on the upper side of the reaction part, and almost all of them are converted into metal halides. Some trace metal hydride may be collected at the bottom of the reaction section.

In this case, it is possible to cause a wasteful reaction between the metal hydride and the metal organic hydride while circulating the reaction part with a solvent.

The reaction product in a gaseous state is separated from the lower part of the reaction part, and the liquid part may be discharged to the outside through a second outlet formed at the bottom of the reaction part through a pump part for later processing or recovery. The residue of the liquid phase discharged from the vertical reactor for producing silane according to the present invention may be discharged at an appropriate speed within a range in which a certain amount of liquid can be maintained at the bottom of the apparatus.

On the other hand, depending on the operation of the reactor, the outflow rate of the liquid is too slow may precipitate the solid phase, in order to prevent the precipitation of the solid phase may be further provided with a separate stirring device at the bottom of the reactor.

By providing a stirring device as described above it is possible to discharge the liquid re-introduced to the lower portion of the reaction portion at a high speed, the solid phase may be discharged in a mixed state without being precipitated.

On the other hand, the reaction is first started by dissolving the introduced silicon halide in the solvent of the metal hydride, and then reacting with the metal hydride, which is not established, that is, at the initial reaction start-up There is a fear that the silicon halide and the metal hydride may not completely complete the reaction.

Therefore, in this case, silicon halides flowing from the second inlet formed on the lower side of the reaction unit may be introduced into the first inlet formed on the upper side of the reaction unit by using the pump unit, thereby reducing the loss of reactants due to the insufficient initial reaction conditions. According to the continuous recovery method of silane according to the present invention, such a process may be performed until the reactor is operated normally.

In addition, according to the continuous recovery method of the silane according to the present invention, in the reaction zone formed in the upper and lower portions of the reaction portion, there is no reaction between the metal hydride and silicon halide, because the This is because the metal hydride and the silicon halide introduced to the lower side of the reaction part are converted into monosilane and metal halide, respectively, by reacting at the stop part of the reaction part.

As described above, in the continuous recovery method of silane according to the present invention, all the reactions are concentrated in the central region of the reaction part including one or more reaction zones, and the upper part of the reaction part is continuously made so that the main reaction occurs at the stop part of the reaction part. And it can be adjusted while changing the inflow of the raw material or the temperature of the reaction zone to the bottom.

In other words, if the stoichiometric relationship of the sample is destroyed, it can be adjusted to change the amount of raw material flowing into the reaction part or to control the reaction at the stop part of the reaction part by controlling the heat of reaction using a heat exchanger or the like. have.

Hydrogenation exothermic reaction of silicon halide proceeds in the reaction section, and a large amount of heat is released, and in particular, various cooling means known in the art may be applied to remove the reaction heat of each reaction section.

If the vertical reactor for producing silane according to the present invention is designed to be driven at a low power, the cooling means may be arranged on one side of the reaction part to adjust the cooling flow flowing into the cooling means while controlling the temperature of each reaction zone.

The method of controlling the emission of the heat of reaction and controlling the main reaction zone to occur at the stop of the reaction section may vary, for example, the stoichiometric reaction can be secured using the following two methods.

In the first method, an appropriate amount of cooling liquid can be supplied to the reaction unit so that the preset temperature is maintained accurately. Such a cooling liquid is supplied sufficiently so that a given device does not exceed the maximum hot spot temperature, and the resulting temperature change graph shows how the reaction is flowing inside the reaction part according to the height of the reaction part, and the current device. Show where the reaction is concentrated.

According to the second method, in each reaction zone of the reactor, the temperature of the reaction section can be controlled by changing the cooling liquid consumption regardless of the excess capacity of the reaction section. Regardless of the technical method or type, the enthalpy of the cooling liquid at the outlet and inlet of the reactor is controlled in each reaction zone. The graph of the change in heat emission in each reaction zone located along the height of the reactor allows you to determine how the reaction is flowing and what part of the reactor is currently concentrated.

Herein, all kinds of heat carriers may be used as the cooling liquid; Preferably water can be used.

Specifically, the reaction temperature is maintained in the range of approximately 10 ℃ to 80 ℃ under a reaction pressure of 1 atm (absolute) to 1.2 atm (absolute), when using a monosilane or a compound having a boiling point similar to monosilane as a solvent, 20 It can hold | maintain in the range of ° C-50 ° C.

On the other hand, when using a compound such as diethylene glycol dimethyl ether (diethylene glycol dimethyl ether) as a solvent, the reaction temperature can be maintained between 30 ℃ and 70 ℃. At this time, when the pressure is increased to 10 atm (absolute), the heat of reaction rises in proportion to the vapor density pressure of the solvent, but cannot exceed 110 ° C.

As the temperature rises, the reaction process speeds up, but if the vapor pressure of the solvent rises in part, the loss rate of the solvent may increase with the monosilane flow. In order to reduce solvent losses at the top of the reaction section, a heat exchanger may be installed that condenses and recovers the vaporized solvent at temperatures above the lowest permissible temperature of the process (not more than 10 ° C.).

In order to reduce the loss of solvent in the flow of the first raw material flowing into the reaction section, the temperature of the NaAlH ₄ solution fed to the reactor is as low as possible, but higher than the minimum allowable temperature suitable for the reaction process (not more than 10?). Can be adjusted. More specifically, instead of the heat exchanger (condenser) installed on the top of the device, the reaction portion that reacts can serve as a function of the heat exchanger to control the reaction mixture and the temperature of the reactants by stirring.

Such heat exchangers can be considered to manage spatial placement in the main reaction zones within the reactor, and the installation of heat exchangers can control the rate of reaction. For example, when the reaction is slow (when the reaction temperature is low), the heater can be heated to increase the reaction rate or cool down to reduce the reaction rate.

The reaction section of the reactor ensures effective contact between the gas and the liquid, and at the same time any form known as long as it can accommodate the required amount of liquid in the reaction section.

In the case of mixing reactants present in various forms, a loss of gas flow energy can occur. That is, for example, when using a reactor to react a small amount of reactants in a low power device, the gas flow energy is not sufficient to maintain the device size.

A small amount of metal hydride is contained in the lower portion of the reaction portion, and at the same time, a sufficient amount of silicon halide is contained. Accordingly, silicon halides may be introduced into the reaction section to produce metal halides of the same type as Na ₂ SiF ₆ and to reduce the addition reactions that lead to loss of raw materials with the generation of waste. Not all of the silicon halides are introduced through the bottom of the device, but may be introduced through several inlets separated in several parts depending on the height.

The number of additional inlets of silicon halide introduced into the reaction unit may be 2 to 5, specifically 1 or 2 inlets may be further formed.

The amount of silicon halide flowing into the lower part of the reaction part may be 25 parts by weight to 40 parts by weight based on 100 parts by weight of total silicon halide flowing into the reaction part, and the excess may be additionally introduced through another inlet formed at one side of the reaction part. . In addition, the amount of silicon halide (extra amount of silicon halide) introduced into the device A separately without flowing through the bottom may be 10% to 80% based on 100 parts by weight of the total silicon halide as described above. Can be.

According to the present invention, since the initial sample stream need not be purified metal hydride and silicon halide, it is possible to recover monosilane and metal halide using various mixtures composed of various components.

Example

Hereinafter, the present invention will be described in more detail through examples according to the present invention, but the scope of the present invention is not limited to the examples given below.

Example  One

Silanes were recovered using a vertical reactor for producing silanes with a total height of 2000 mm, a diameter of 250 mm and five reaction zones.

Industrial sodium aluminum hydride produced through the reaction of aluminum, sodium and hydrogen in a toluene solvent was mixed with a diethylene glycol dimethyl ether solvent and used as a first raw material containing metal hydride.

 In addition, tetrafluoro silane obtained by chemical purification was used as silicon halide without mixing additional compounds.

The reactor was installed as described above, and the sodium aluminum hydride solution was supplied at a composition ratio as shown in Table 1 below.

ingredient content NaAlH ₄ 1.46 kg / hr NaAlH ₂ Et ₂ 0.07 kg / hr toluene 2.72 kg / hr Diethylene glycol dimethyl ether 12.75 kg / hr

In addition, tetrafluoro silane gas was supplied in an amount of 2.88 kg / hr through the lower one side of the reaction unit. The process was carried out in a continuous manner at a temperature of 20 ° C. and a pressure of 1.1 atm (absolute), and at the same time, the reaction mixture of Table 2 as a gas product was recovered through the top of the reaction section.

ingredient content SiH ₄ 0.85 kg / hr EtSiH ₃ 0.07 kg / hr

In addition, unreacted tetrafluoro silane was present in the mixture in traces less than the analytical value, and there was substantially no loss of solvent with the gaseous reaction product.

The slurry containing the metal fluoride was continuously discharged through the bottom of the apparatus to the ingredients and contents shown in Table 3 below.

ingredient content NaAlF ₄ 3.49 kg / hr toluene 2.72 kg / hr Diethylene Glycol Dimethyl Ether 12.75 kg / hr

As shown in Table 3 above, no hydrogen-containing silicon compound or metal was present in the slurry.

Here, the initial concentration of the sodium aluminum hydride was adjusted to 8.6% by weight.

Example  2

The toluene solution containing the same industrial sodium aluminum hydride as Example 1 was mixed with an ethylene glycol dimethyl ether (monoglume / dimethoxyethane) solvent and used as a first raw material containing metal hydride.

In Example 1, purified tetrafluoro silicon was used, while in Example 2, contaminated conventional industrial impurities were chlorine hydride, fluorine hydride, hexafluoro. Tetrafluorosilicon containing disiloxane and a small amount of water was used.

The reactor was used in the same manner as in Example 1, and the sodium aluminum hydride solution was supplied in the composition ratio as shown in Table 4.

ingredient content Et ₂ SiH ₂ 0.03 kg / hr Ethylene Glycol Dimethyl Ether 11,310 kg / hr toluene 2.38 kg / hr NaAlH ₄ 1.19 kg / hr Na ₃ AlH ₆ 0.01 kg / hr NaAlH ₂ Et ₂ 0.03 kg / hr

In addition, the composition ratio of the tetrafluoro silane (silicon tetrafluoride / silicon tetrafluoride) in the gas form flowing into the bottom of the device is shown in Table 5.

ingredient content HCl 0.03 kg / hr SiF ₄ 2.19 kg / hr H ₂ O 1 g / hr (SiF ₃ ) ₂ O 0.07 kg / hr

The process was carried out under a temperature of 60 ° C. and a pressure of 1.2 atm (absolute), through which a reaction product in gaseous form was produced with the components and contents shown in Table 6 below.

ingredient content H ₂ 2 g / hr C ₂ H ₆ 20 g / hr SiH ₄ 690 g / h EtSiH ₃ 30 g / hr Ethylene Glycol Dimethyl Ether 920 g / hr toluene 80 g / hr

As shown in Table 6 above, unreacted tetrafluoro silane was present in the mixture in traces less than the assay value.

In addition, in Example 1, due to the high pressure and high temperature process of saturated steam monosilane compared with the case of using diethylene glycol dimethyl ether, together with the reaction product in gaseous form under the conditions described above The loss of solvent was great.

The slurry containing the metal halide was continuously discharged at the bottom of the apparatus, and the amount is shown in Table 7 below.

ingredient content Ethylene Glycol Dimethyl Ether 10.39 kg / hr toluene 2.30 kg / hr Al 0.01 kg / hr NaAlF ₄ 2.30 kg / hr NaAlCl ₄ 0.04 kg / hr Na ₅ Al ₃ F ₁₄ -AlF ₃ 0.43 kg / hr Al ₂ O ₃ 0.02 kg / hr

As shown in Table 7, the slurry contained no hydrogen-containing silicon compound or metal.

1 schematically illustrates a vertical reactor for producing silane according to an embodiment of the present invention and a method for recovering monosilane from silicon halide using metal hydride using the same.

<Description of Major Symbols in Drawing>

100: vertical reactor for producing silane 110: reaction part

120: first inlet 130: second inlet

140: first outlet 150: second outlet

160: third inlet 170: pump unit

Claims (23)

A reaction part including a plurality of reaction zones in which a liquid first material including a metal hydride and a second gas material including a silicon halide react with each other; A first inlet formed on an upper side of the reaction part and introducing a first raw material into the reaction part; A second inlet formed on one side of the lower portion of the reaction part and introducing a second raw material into the reaction part; A first outlet formed at an upper end of the reaction part and discharging silane gas generated in the reaction part; And Is formed in the bottom of the reaction unit, a vertical reactor for producing silane comprising a second outlet for discharging the metal halide of the liquid generated in the reaction unit. The method of claim 1, Reaction zone is a vertical reactor for producing a silane comprising a reaction rack formed so that the flow of the first raw material of the introduced liquid is suspended for a certain time, and then flows. The method of claim 1, The reaction zone is a vertical reactor for producing silane formed from 3 to 30 stages in a vertical direction from top to bottom. The method of claim 1, Reaction unit is a vertical reactor for producing silane further comprises a stirring device for mixing the first material and the second material introduced. The method of claim 4, wherein The stirring device includes a stirring shaft formed along the vertical direction from the top to the bottom of the reaction unit; And at least one blade attached to the stirring shaft to mix the first raw material and the second raw material introduced into the reaction unit. The method of claim 1, Vertical reactor for producing silane further comprises a heat sensing unit for measuring the temperature of the reaction unit. The method of claim 1, Vertical reactor for producing silane further comprises a heat exchanger for absorbing or supplying heat depending on the temperature of the reaction portion. The method of claim 1, It is formed on the lower side of the reaction portion, the vertical reactor for producing silane further comprises a third inlet for introducing the liquid metal halide discharged through the second outlet to the reaction unit. The method of claim 8, The vertical reactor for producing silane further comprises a pump unit for introducing the liquid metal halide discharged through the second outlet through the first inlet or the third inlet to the reaction unit. 10. A continuous recovery method of silane for recovering silane gas using a vertical reactor for producing silane according to claim 1. The method of claim 10, A first step of introducing the first liquid material including the metal hydride into the upper portion of the reaction portion through the first inlet formed on the upper side of the reaction portion; A second step of introducing a second raw material of a gaseous phase including silicon halide into the lower portion of the reaction portion through a second inlet formed at one lower portion of the reaction portion; A third step of reacting the first raw material and the second raw material introduced into the reaction unit in the first step and the second step; And And a fourth step of separating and discharging the silane gas and the liquid metal halide formed in the third step. The method of claim 11, In the first step, the metal hydride is a method for the continuous recovery of the silane is a compound represented by the formula (1) or (2): [Formula 1] AH ₄ In Formula 1, A is lithium, sodium or potassium, [Formula 2] AAlH ₄ In Formula 2, A is lithium, sodium or potassium. The method of claim 11, In the first step, the first raw material is a continuous recovery method of the silane comprising at least one solvent selected from ether or cyclic ether. The method of claim 13, Solvent is a continuous recovery method of a silane comprising at least one selected from the group consisting of diethylene glycol dimethyl ether, ethylene glycol dimethyl ether, 1,4-dioxane, butyl ether and derivatives thereof. The method of claim 13, Solvent is a continuous recovery method of the silane further comprises one or more selected from the group consisting of toluene, xylene, pentane, hexane and heptane. The method of claim 11, In the second step, the silicon halide is a continuous recovery method of the silane is a compound represented by the formula (3) or (4): (3) SiX _n Y _{4 -n} In Formula 3, X and Y are each independently fluorine, chlorine or bromine, n is an integer of 1 to 4, [Formula 4] H _n SiX _{4 -n} In Formula 4, X is fluorine, chlorine or bromine, n is an integer of 1 to 3. The method of claim 11, In a third step, the reaction unit is a continuous recovery of the silane pressure is 1.2 atm (absolute) to 1.4 atm (absolute). The method of claim 11, In a third step, the reaction is a continuous recovery of silane is carried out at a temperature of 10 ℃ to 110 ℃. The method of claim 11, In a third step, the reaction is a continuous recovery of silane is carried out at a temperature of 30 ℃ to 70 ℃. The method of claim 11, In the third step, the reaction is a continuous recovery method of silane is carried out under the conditions that the pressure of the reaction portion is 1.2 atm (absolute), the temperature is 80 ℃ to 110 ℃. The method of claim 11, The third step includes the steps of (1) measuring the temperature of the reaction part; And And (2) controlling the flow rate of the first raw material and the second raw material flowing into the reaction unit according to the temperature measured in the step (1). The method of claim 11, The third step comprises the steps of (A) measuring the temperature of the reaction section; And And (B) further supplying or recovering heat to the reaction part in accordance with the temperature measured in step (A). The method of claim 11, Re-flowing the liquid metal halide discharged to the bottom of the reaction portion to the upper or lower portion of the reaction portion further continuous recovery method of silane.

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