Exhaust gas cleaning process

Abstract

A purification process for exhaust gas comprising the following steps: separating the exhaust gas, which is derived after performing a polysilicon deposition process by a chemical vapor deposition (CVD) reaction, into a non-condensed phase stream and a condensed phase stream; wherein the exhaust gas is condensed to more than -30°C and less than 10°C to separate into the non-condensed phase stream and the condensed phase stream; passing the non-condensed phase stream through a first catalytic reactor to reduce the concentration of hydrogen chloride, wherein the catalyst used in the first catalytic reactor includes a transition metal; and separating the chlorosilane-based compound of the condensed phase stream according to its boiling point.

Description

BACKGROUND OF THE INVENTION (a) Technical field of the invention

[0001] The present invention relates to an exhaust gas purification method and apparatus. More specifically, the present invention relates to an exhaust gas purification method and apparatus capable of reducing the hydrogen chloride concentration and separating high-purity hydrogen from the exhaust gas released after performing a polysilicon deposition process using a chemical vapor deposition reaction.

[0002] This application claims priority to Korean Patent Application No. 10-2014-0009101 and Korean Patent Application No. 10-2014-0009102, both filed with the Korean Intellectual Property Office (KIPO) on January 24, 2014, and Korean Patent Application No. 10-2014-0051668, filed with KIPO on April 29, 2014. The contents of these documents are incorporated herein by reference in their entirety. (b) Description of related art

[0003] One of the well-known manufacturing processes for polysilicon for solar cells is a process based on the lamination of polysilicon in a chemical vapor deposition (CVD) reactor, also known as the Siemens process.

[0004] Silicon filaments, which are typically used in the Siemens process, are exposed to trichlorosilane with a carrier gas at a high temperature of more than 1000°C.

[0005] The trichlorosilane gas decomposes and deposits silicon on a heated silicon filament phase, causing the heated silicon filament to grow, as shown in reaction equation 1 below. [Reaction equation 1] 2HSiCl 3 → Si + 2HCl + SiCl 4

[0006] After performing the polysilicon deposition process by chemical vapor deposition as described above, chlorosilane-based compounds such as dichlorosilane, trichlorosilane or silicon tetrachloride, or hydrogen and hydrogen chloride are released as reaction by-products.

[0007] Off-gas (OGR) containing these chlorosilane-based compounds, hydrogen, and hydrogen chloride is generally recovered and recycled in four stages: 1) condensation and compression, 2) absorption and distillation of hydrogen chloride (HCl), 3) adsorption of hydrogen (H 2 ), 4) Separation of the chlorosilane-based compounds.

[0008] Specifically, this means that the gas discharged from the polysilicon deposition reactor is fed into a condensation and compression process and cooled, after which it is fed into a separator. Temperature-induced separation occurs; a condensed phase stream of chlorosilane-based compounds is transferred to a hydrogen chloride (HCl) distillation column, and a non-condensed phase stream is transferred to a lower part of the hydrogen chloride absorption column. At this time, the hydrogen composition (H 2) in the non-condensed phase stream at about 90 mol% or more.

[0009] The condensed phase stream, in which the hydrogen chloride component is removed from the hydrogen chloride distillation column, is mixed and sprayed onto the top of an absorption column, and the chlorosilane-based compound component and the hydrogen chloride in the non-condensed phase streams are absorbed and removed.

[0010] A gas stream from which the chlorosilane-based compound component and hydrogen chloride have been largely removed is passed into a column filled with activated carbon. The remaining chlorosilane-based compound component and hydrogen chloride are absorbed, thereby recovering high-purity hydrogen.

[0011] The hydrogen purification process described above is a pressure swing adsorption (PSA) process adapted for the separation and purification of polysilicon off-gas.

[0012] Fig. 1 illustrates a prior art exhaust gas purification device.

[0013] With reference to Fig. 1, the cleaning device 300 for exhaust gas according to the state of the art has a separator 315 , an absorption column 325 , a first distillation column 345 , an adsorption column 355 and a second distillation column 360 on.

[0014] The reactor for polysilicon deposition 305 derived exhaust gas 301 is in a first cooler 310 cooled, then into a separator 315 and into a non-condensed gas phase stream 302containing an excess of hydrogen and a condensed liquid phase stream 303 containing an excess of a chlorosilane-based compound. At that time, the amount of 301 contained hydrogen chloride largely in the non-condensed phase stream 302 distributed.

[0015] The non-condensed at the top of the separator 315 derived gas phase stream 302 is additionally stored in a second cooler 320 cooled, pressurized and then transferred to an absorption column 325 At that time, the hydrogen chloride and chlorosilane components, each in the non-condensed phase stream 302 are contained, largely by means of a chlorosilane-based current 307 which is fed into a first distillation column 345 is removed as described below. On the other hand, the gas at the top of the absorption column 325derived hydrogen stream 304 finally in the adsorption column 355 cleaned and returned to the cycle.

[0016] The one at the bottom of the separator 315 derived liquid phase stream 303 is pumped 350 with a from the absorption column 325 derived current 306 mixed and then into a first distillation column 345 A gaseous hydrogen chloride is separated and collected at the top of the first distillation column 345 derived, and a chlorosilane-based stream 307 from which the hydrogen chloride has been removed, is discharged at the bottom. At that time, the process consumes at the first distillation column 345more than about 40% of the total energy of the purification process and is operated using a high-energy process, which consumes the most energy. Most chlorosilane-based streams 307 are again pumped 335 and a cooler 330 to the absorption column 325 transferred and used for the absorption of hydrogen chloride and chlorosilane in the non-condensed phase stream 302 The remainder is sent to a second distillation column 360 transferred, separated into di- / trichlorosilane and silicon tetrachloride and then returned to the cycle.

[0017] In the conventional purification process as described above, in order to remove hydrogen chloride from the non-condensed stream 302 to remove the condensed phase current 307 from which the hydrogen chloride component from the first distillation column 345was removed, onto the absorption column 325 sprayed and fed to it. For this process, it is necessary to have a 325 to cool and at the first distillation column 345 This creates the problem of inefficient energy consumption. In addition, the condensed stream must be removed from the top of the absorption column to ensure the purity of the non-condensed phase. 325 is recycled excessively often and is therefore a major reason for the increase in energy costs in the exhaust gas cleaning process. SUMMARY OF THE INVENTION

[0018] In order to solve the above-mentioned problems of the prior art, it is an object of the present invention to provide an exhaust gas purification method and an exhaust gas purification apparatus capable of effectively and with high energy efficiency removing hydrogen chloride gas from the exhaust gas generated in the polysilicon deposition process carried out by a chemical vapor deposition (CVD) reaction.

[0019] To achieve this object, the present invention provides an exhaust gas purification method comprising the following steps: Passing the exhaust gas released after the polysilicon deposition process, which is carried out by means of a chemical vapor deposition (CVD) reaction, through a catalytic reactor containing an ion exchange resin catalyst to reduce the hydrogen chloride concentration; and Passing the exhaust gas through the catalytic reactor followed by separation of hydrogen and the chlorosilane-based compounds contained in the passed exhaust gas.

[0020] Furthermore, the present invention provides an exhaust gas purification device comprising: A catalytic reactor containing an ion exchange resin catalyst and reducing the hydrogen chloride concentration by passing the exhaust gas released after the polysilicon deposition process carried out by a chemical vapor deposition (CVD) reaction; and a separation device that separates the hydrogen and the chlorosilane-based compounds from the exhaust gas passed through the catalytic reactor.

[0021] Furthermore, the present invention provides an exhaust gas purification method comprising the steps of: Separating the exhaust gas released after the polysilicon deposition process carried out by means of a chemical vapor deposition (CVD) reaction into a non-condensed phase stream and a condensed phase stream; and Passing the condensed phase stream through a catalytic reactor containing an ion exchange resin catalyst to reduce the hydrogen chloride concentration.

[0022] Furthermore, the present invention provides an exhaust gas purification device comprising: A separation device that separates the exhaust gas released after the polysilicon deposition process carried out by means of a chemical vapor deposition (CVD) reaction into a non-condensed phase stream and a condensed phase stream; and a Catalytic reactor containing an ion exchange resin catalyst that reduces the hydrogen chloride concentration from the condensed phase stream.

[0023] Furthermore, the present invention provides an exhaust gas purification method comprising the steps of: Separating the exhaust gas released after the polysilicon deposition process, which is carried out by means of a chemical vapor deposition (CVD) reaction, into a non-condensed phase stream and a condensed phase stream; Passing the non-condensed phase stream through a first catalytic reactor to reduce the hydrogen chloride concentration; and Separation of the chlorosilane-based compounds of the condensed phase stream according to the boiling point.

[0024] According to the exhaust gas purification method and purification apparatus of the present invention, hydrogen chloride is removed from the exhaust gas emitted from the polysilicon deposition reactor by converting it into chlorosilane-based compounds using a catalytic reactor, instead of performing the condensation and compression process and performing separation by boiling point difference. This can reduce some of the problems caused by hydrogen chloride, such as corrosion, hydrogen chloride leakage, deterioration of the separation membrane, the phenomenon of elution of impurities contained in activated carbon, and the like; it is possible to produce and recycle high-purity hydrogen from which hydrogen chloride has been removed.

[0025] Furthermore, the purification method and the purification device for exhaust gas according to the invention are relatively simple and can be realized using low-energy devices, thereby reducing the operating costs for the device and the process.

[0026] In addition, in the exhaust gas purification process according to the invention, no absorption column is required to remove hydrogen chloride, which makes it operationally possible to lower the pressure in the compression step of the uncondensed phase discharged after the first condensation and separation step compared to the conventional pressure ranges, thereby further improving the energy effects in reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Fig. 1 illustrates a prior art exhaust gas purification device.

[0028] Fig.2 illustrates an exhaust gas purification device according to an embodiment of the invention.

[0029] Fig. 3 illustrates an exhaust gas purification device according to an embodiment of the invention.

[0030] Fig. 4 illustrates an exhaust gas purification device according to an embodiment of the invention.

[0031] Fig. 5 illustrates an exhaust gas purification device according to an embodiment of the invention.

[0032] Fig. 6 illustrates an exhaust gas purification device according to an embodiment of the invention.

[0033] Fig. 7 illustrates a flowchart of an exhaust gas purification method according to an embodiment of the present invention.

[0034] Fig. 8 illustrates a flowchart of an exhaust gas purification method according to an embodiment of the present invention.

[0035] Fig.9 illustrates a flowchart of an exhaust gas purification method according to an embodiment of the present invention.

[0036] Fig. 10 illustrates a flowchart of an exhaust gas purification method according to an embodiment of the present invention.

[0037] Fig. 11 illustrates a flowchart of an exhaust gas purification method according to an embodiment of the present invention.

[0038] Fig. 12 illustrates a flowchart of an exhaust gas purification method according to an embodiment of the present invention.

[0039] Fig. 13 illustrates a flowchart of an exhaust gas purification method according to an embodiment of the present invention.

[0040] Fig. 14 illustrates a flowchart of an exhaust gas purification method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] In this disclosure, terms such as "the first," "the second," etc., are used to describe various elements; they are intended solely for the purpose of distinguishing one element from another.

[0042] The terms used in this disclosure describe only exemplary embodiments and are not intended to limit the scope of the present invention. Singular expressions are intended to include the plural meaning unless the context clearly indicates otherwise. The terms "comprising," "comprising," or "having," as used in this disclosure, are intended to define the presence of features, integers, steps, constituent elements, or combinations thereof; it is understood that the presence and additional possibilities of one or more other features, integers, steps, or constituent elements, or combinations thereof, are not thereby precluded.

[0043] Furthermore, when reference is made to each layer or element being formed “on” or “on top of” the respective layers or elements, it means that each layer or element is formed on top of the respective layers or elements, or that the other layer or element may be additionally formed between the respective layers or on the object or substrate.

[0044] While the present invention is susceptible to various modifications and alternative forms, specific embodiments are illustrated and described in detail below. It should be understood, however, that this description is not intended to limit the present invention to the particular embodiments disclosed herein, and instead, all modifications, equivalents, and substitutions, both narrow and broad, are intended to be included within the scope of the invention.

[0045] The following is a description of the gas purification method and apparatus according to the invention in further detail.

[0046] According to one embodiment of the invention, there is provided an exhaust gas purification method comprising the steps of: passing the exhaust gas released after the polysilicon deposition process carried out by a chemical vapor deposition (CVD) reaction through a catalytic reactor containing an ion-exchange resin catalyst for reducing the hydrogen chloride concentration; passing the exhaust gas through the catalytic reactor; then separating the hydrogen and chlorosilane-based compounds contained in the passed exhaust gas.

[0047] First, the term “off-gas” in the present disclosure refers exclusively to a gas released after performing a polysilicon deposition process, in particular a polysilicon deposition process by chemical vapor deposition (CVD) reaction, and may include a variety of compounds, but may be a gas containing hydrogen chloride (HCl), hydrogen (H 2 ) and chlorosilane-based compounds.

[0048] In addition, the exhaust gas as a whole includes a non-condensed gas state, a condensed liquid state, or a mixed state thereof; it may further include not only a gas released immediately after performing a polysilicon deposition process, but also a gas having a different composition from a gas released immediately after performing a polysilicon deposition process from another process.

[0049] Furthermore, throughout the disclosure, the term "condensed phase stream" refers to a stream in which exhaust gas in the liquid state undergoes processes such as cooling, pressurization, separation, and purification, and includes both a stream formed in one step and a stream formed by multi-step processes of two or more steps, or a stream mixed therebetween. Furthermore, the term "condensed phase stream" is interchangeable with that of "liquid phase stream." On the other hand, the condensed phase stream, when mixed with a stream derived from one or more processes, may be in a state where a portion of the gas (for example, about 10% by weight or less) is mixed. The case where a portion of the gas is mixed as described above is included in the condensed phase stream of the present invention.

[0050] Furthermore, throughout this disclosure, the term "uncondensed phase stream" refers to a stream in which exhaust gas in a gaseous state undergoes heating, depressurization, separation, purification, and the like, and includes both a stream formed in one step and a stream formed by multi-step processes of two or more steps, or a stream mixed therebetween. Furthermore, the term "uncondensed phase stream" is interchangeable with that of a gas phase stream. On the other hand, the uncondensed phase stream may be mixed with a stream derived from one or more processes and may be in a state where a portion of the liquid (e.g., about 15% by weight or less) is mixed by condensation through heat exchange.Furthermore, the case where a part of the gas is mixed as described above, it is included in the condensed phase stream according to the invention. .

[0051] As one of the known methods in polysilicon production, chemical vapor deposition (CVD) refers to a method of depositing silicon on a silicon filament by heating the silicon filament, injecting a gaseous silicon precursor compound such as trichlorosilane, followed by performing thermal decomposition.

[0052] As a by-product of the polysilicon deposition process, which is carried out by means of a chemical vapor deposition reaction, an off-gas is produced which contains chlorosilane-based compounds, such as dichlorosilane (SiH 2 Cl 2 ), trichlorosilane (SiHCl 3 ) and silicon tetrachloride (SiCl 4 ) as well as hydrogen chloride (HCl), hydrogen (H 2) and the like.

[0053] Hydrogen- and chlorosilane-based compounds can be separated from various components contained in such exhaust gas and recycled to the chemical vapor deposition process. However, among the components contained in the exhaust gas, hydrogen chloride is difficult to recycle and can cause corrosion of the equipment; therefore, it is desirable to remove hydrogen chloride after the process. However, the removal of hydrogen chloride is not easy due to its low boiling point and molecular weight.

[0054] In the conventional off-gas purification process, the off-gas discharged from the polysilicon deposition reactor is fed to the compression and condensation process and subjected to a thermal separation process. Accordingly, the condensed phase stream containing chlorosilane-based compounds is fed to a distillation column to remove hydrogen chloride at the top, and the uncondensed phase stream is fed to the bottom of the absorption column.

[0055] The condensed phase streams, from which the hydrogen chloride component (HCl) has been removed by the distillation column, are mixed by spraying at the top of the absorption column to absorb and remove the chlorosilane-based component and hydrogen chloride (HCl) in the non-condensed phase stream.

[0056] Subsequently, hydrogen streams from which the majority of the chlorosilane and hydrogen chloride components have been removed are fed into a column filled with activated carbon and remaining hydrogen chloride and chlorosilane-based compounds are absorbed by the activated carbon, thereby recovering high-purity hydrogen.

[0057] In the conventional off-gas purification process described above, to remove the hydrogen chloride contained in the uncondensed phase stream, the condensed phase stream, from which the hydrogen chloride component has been removed by the distillation column, is sprayed and fed to the absorption column. This process requires cooling at the absorption column and heating at the distillation column. However, the problem is inefficient energy consumption. Furthermore, to ensure the purity of the uncondensed phase, the condensed stream is excessively recycled to the absorption column, which is a major cause of the increased energy costs of the off-gas purification process.

[0058] The cleaning method of the present invention, however, is relatively simple compared to the conventional method and can be carried out with low-energy consumption devices, thus reducing the operating costs of the equipment and the method.

[0059] In the exhaust gas purification method according to an embodiment of the present invention, hydrogen chloride can be converted into trichlorosilane and / or silicon tetrachloride by passing the exhaust gas through a catalytic reactor instead of separating hydrogen chloride into a gas phase by the boiling point difference in the distillation column, thereby reducing the discharge of hydrogen chloride.

[0060] That is, according to the purification method according to one embodiment of the present invention, a catalytic reactor containing an ion exchange resin catalyst is prepared, and the exhaust gas discharged after performing a polysilicon deposition process by a chemical vapor deposition (CVD) reaction is passed through the catalytic reactor to reduce the concentration of hydrogen chloride contained in the exhaust gas.

[0061] For the ion exchange resin catalyst described above, a cyclic amine compound, a styrene-based polymer having an amine group, a styrene-divinylbenzene-based polymer having an amine group, an acrylic polymer having an amine group, or mixtures thereof can be used. Examples of the cyclic amine compound may include vinylpyridine, pyridazine, pyrimidine, pyrazine, piperidine, pyrrolidine, and the like, but the invention is not limited to these.

[0062] The amine groups are not specifically limited, but tertiary or quaternary amine groups may be preferred for the effectiveness of the ion exchange resin. Furthermore, styrene- or styrene-divinylbenzene-based polymers can be prepared using conventional methods, but are not specifically limited to these. For example, the phthalimide method can be used as an exemplary method for preparing the catalyst. In this case, a divinylbenzene-crosslinked polystyrene resin is reacted with phthalimide or phthalimide derivatives. The resulting hydrolysis product of the primary polyvinylbenzylamine is reacted with formaldehyde and formic acid. This allows a polystyrene resin having a tertiary amine group to be obtained.

[0063] In addition, the ion exchange resin catalyst is widely available commercially; the acrylic polymer variant can have product names such as Amberlite IRA-958, Amberlite IRA-67 or similar and the styrene or styrene-divinylbenzene based polymer variant can have product names such as Amberlyst ® A-21, Dowex M-43, LEWATIT ® MP 62 WS or similar. The cyclic amine compound may have product names such as Reillex ® HP, Reillex ® 425 or similar.

[0064] According to one embodiment of the present invention, the catalytic reactor may contain an amine-based compound. Examples of the amine-based compound may include an amine, an ammonium salt, an aminosilane, an aminosiloxane, an aminoalkoxysilane, or the like, but the invention is not limited to these.

[0065] According to the purification method of the present invention, the hydrogen chloride contained in the exhaust gas is converted into trichlorosilane (SiHCl3) and / or silicon tetrachloride (SiCl 4 ). Furthermore, the use of the ion exchange resin catalyst described above can achieve the effects of removing the foreign substances contained in the exhaust gas. [Reaction formula 1] SiH 2 Cl 2 + HCl → SiHCl 3 + H 2 [Reaction formula 2] SiHCl 3 + HCl → SiCl 4 + H 2

[0066] As described above, while the exhaust gas containing hydrogen chloride, hydrogen and chlorosilane-based compounds is passed through the ion exchange resin catalyst, hydrogen chloride can be converted into trichlorosilane and / or silicon tetrachloride according to reaction formulas 1 and / or 2.

[0067] Specifically, the reaction described above can be carried out through the following process. First, the hydrogen chloride module forms an amine hydrochloride or an amine chlorosilane salt through the amine functional groups of the ion exchange resin catalyst. Furthermore, Cl ions of the amine hydrochloride can attack the silicon atoms of the trichlorosilane through an acid-catalytic reaction, thereby releasing a hydrogen atom and forming silicon tetrachloride.

[0068] According to the present invention, the composition ratio of the components contained in the exhaust gas is not specifically limited. In the case of the exhaust gas discharged after a polysilicon deposition process by a chemical vapor deposition reaction, the hydrogen content accounts for more than 50 mol% of the total exhaust gas; the remainder may be hydrogen chloride and chlorosilane-based compounds. Moreover, the molar ratio of hydrogen (H2) to hydrogen chloride (HCl) may be approximately 99:1. On the other hand, for more effective removal of hydrogen chloride, the number of moles of trichlorosilane may be included in a number of moles of 1 or more relative to 1 mole of hydrogen chloride.

[0069] The hydrogen chloride content in the total exhaust gas can be reduced to, for example, approximately 80 mol% or more, for example approximately 80 to approximately 100 mol%, preferably approximately 90 to 99.9 mol%, relative to the content before passing through the catalytic reactor.

[0070] The step of passing the exhaust gas through the catalytic reactor containing the ion exchange resin catalyst can be carried out in a temperature range of about -40 to about 200°C, but preferably at about -20 to about 150°C, and more preferably at about 0 to about 100°C, at a pressure of about 1 to about 30 bar, preferably about 1 to about 20 bar, and more preferably about 1 to about 10 bar, but is not limited to these values. Within the activation range of the ion exchange resin catalyst, the conditions can be changed accordingly.

[0071] After the exhaust gas is passed through the catalytic reactor containing the ion exchange resin catalyst, a separation process is carried out to remove the hydrogen and the chlorosilane-based compounds contained in the exhaust gas.

[0072] This separation method can be used without any specific limitation as long as it is a method for separating high boiling point compounds and low boiling point compounds from the mixture, and can be carried out by, for example, a distillation method, a separation membrane method, a gas-liquid separation method or a combination of these.

[0073] In particular, according to one embodiment of the present invention, the offgas passed through the catalytic reactor is first fed to the distillation column. Hydrogen is removed from the top of the first distillation column, and the chlorosilane-based compound is removed from the bottom thereof. The chlorosilane-based compound removed from the bottom is fed to the second distillation column. Dichlorosilane and trichlorosilane can be removed from the top of the second distillation column, and silicon tetrachloride can be separated from the bottom of the second distillation column. All of the separated components, except for the silicon tetrachloride, can be recycled to the feed for conducting the polysilicon deposition process.

[0074] According to another embodiment of the present invention, the exhaust gas passed through the catalytic reactor is first cooled and fed into a separator, and then separated into a condensed phase and a non-condensed phase. Among the components separated by the separator, the non-condensed phase containing excessive hydrogen is purified by the separation membrane, and the purified hydrogen can be recycled for the polysilicon deposition process. The condensed phase stream containing the chlorosilane-based compounds that did not pass through the separation membrane can be fed into the distillation column and separated into gas-phase dichlorosilane and trichlorosilane and liquid-phase silicon tetrachloride. Among the separated components, all except the silicon tetrachloride can be fed to the feed for conducting the polysilicon deposition process.

[0075] According to another embodiment of the present invention, there is provided an exhaust gas purification device comprising: a catalytic reactor containing an ion exchange resin catalyst and reducing the concentration of hydrogen chloride by passing the exhaust gas released after performing a polysilicon deposition process by a chemical vapor deposition (CVD) reaction; and a separation device that separates the hydrogen and a chlorosilane-based compound from the exhaust gas passed through the catalytic reactor.

[0076] In this context, the description of the catalytic reactor containing an ion exchange resin catalyst and the exhaust gas is the same as that in the purification process described above.

[0077] The separation device can be used without particular limitation if it is a conventional device capable of separating high- and low-boiling-point compounds from the mixture. For example, the device may include a distillation device, a separation membrane device, a separator, a gas-liquid separator, or the like. Additionally, the separation device may be installed at the rear end of the catalytic reactor and operated with different devices or under different operating conditions depending on the object to be separated.

[0078] Hereinafter, the cleaning apparatus according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0079] Fig. 2 illustrates an exhaust gas purification device according to an embodiment of the present invention.

[0080] In relation to Fig. 2, includes the cleaning device 10 according to one embodiment of the present invention, a catalytic reactor 3 and a distillation column 6 .

[0081] In the catalytic reactor 3 The exhaust gas from the reactor for the deposition of polysilicon 1 is discharged, is passed on for separation and purification. At this point, the exhaust gas can 2 contain more than 50 mol% hydrogen, about 0.01 to about 5 mol% hydrogen chloride, about 0.01 to about 10 mol% dichlorosilane, about 0.01 to about 25 mol% trichlorosilane, and about 0.01 to about 10 mol% silicon tetrachloride, without limitation.

[0082] A catalytic reactor 3 is treated with an ion exchange resin catalyst 4 filled.

[0083] The exhaust 2 is produced by a catalytic reactor 3, which is treated with an ion exchange resin catalyst 4 filled, and in the catalytic reactor 3 Hydrogen chloride can be converted into trichlorosilane and / or silicon tetrachloride according to the reaction formulas 1 and / or 2 described above. The catalytic reactor 3 can be operated under temperature conditions of about -40 to about 200°C, preferably from about -20 to about 150°C, and more preferably from about 0 to about 100°C, without being limited thereto, and can be varied within a range that allows the ion exchange resin catalyst 4 not deactivated.

[0084] In addition, the operating pressure is in the range of about 1 to about 30 bar, preferably about 1 to about 20 bar, and more preferably about 1 to about 10 bar, but can be varied within a range that does not affect the activity of the ion exchange resin catalyst 4and the operation of the catalytic reactor 3 impaired.

[0085] The catalytic reactor 3 conducted mixed gas 5 is used for separation and purification to the distillation column 6 which is connected to the rear end of the catalytic reactor 3 The catalytic reactor can 3 The mixed gas passed through the reactor may contain more than 50 mol% hydrogen, about 0.01 to about 5 mol% dichlorosilane, about 0.01 to about 25 mol% trichlorosilane, and about 0.01 to about 30 mol% silicon tetrachloride.

[0086] In the distillation column 6 the mixed gas can 5 separated into hydrogen, dichlorosilane and trichlorosilane mixed gas and liquid silicon tetrachloride and fed into the reactor for the deposition of polysilicon for recycling 1 be traced back.

[0087] Fig.3 illustrates an exhaust gas purification device according to an embodiment of the present invention.

[0088] In relation to Fig. 3, includes the cleaning device 100 for exhaust gas according to an embodiment of the present invention, a catalytic reactor 130 , a first distillation column 160 and a second distillation column 190 .

[0089] In the catalytic reactor 130 The exhaust gas from the reactor for the deposition of polysilicon 110 is discharged, is passed on for separation and purification. At this point, the exhaust gas can 120 contain more than 50 mol% hydrogen, about 0.01 to about 5 mol% hydrogen chloride, about 0.01 to about 10 mol% dichlorosilane, about 0.01 to about 25 mol% trichlorosilane, and about 0.01 to about 10 mol% silicon tetrachloride, without limitation.

[0090] The catalytic reactor 130 is treated with an ion exchange resin catalyst 140 filled.

[0091] The exhaust 120 is produced by the catalytic reactor 130 which is treated with an ion exchange resin catalyst 140 filled, and in the catalytic reactor 130 Hydrogen chloride can be converted into trichlorosilane and / or silicon tetrachloride according to the reaction formulas 1 and / or 2 described above. The catalytic reactor 130 can be operated under temperature conditions of about -40 to about 200°C, preferably from about -20 to about 150°C, and more preferably from about 0 to about 100°C, without being limited thereto, and can be varied within a range that allows the ion exchange resin catalyst 140 not deactivated.

[0092] In addition, the operating pressure is in the range of about 1 to about 30 bar, preferably about 1 to about 20 bar, and more preferably about 1 to about 10 bar, but can be varied within a range that does not affect the activity of the ion exchange resin catalyst 140 and the operation of the catalytic reactor 130 impaired.

[0093] The catalytic reactor 130 conducted mixed gas 150 is fed into the first distillation column 160 flowed in. Hydrogen 111 is at the top of the first distillation column 160 separated and the chlorosilane-based compound 170 is discharged below. At this point, the first distillation column 160 operated at a low temperature below the boiling point of dichlorosilane to produce hydrogen 111 and the chlorosilane-based compound 170In addition, to increase the separation efficiency, a cooler is installed in front of the first distillation column 160 installed to control the temperature of the mixed gas 150 The steam from the base of the first distillation column 160 released chlorosilane-based compound 170 may contain about 5 to about 15 mole percent dichlorosilane, about 40 to about 60 mole percent trichlorosilane, and about 30 to about 50 mole percent silicon tetrachloride.

[0094] The chlorosilane-based compound 170 becomes a storage tank 180 The water from the storage tank 180 derived chlorosilane-based compound is pumped 114 to the second distillation column 190 Dichlorosilane and trichlorosilane are released in the gaseous state at the top of the second distillation column 190and silicon tetrachloride is discharged in a liquid state at the bottom. At this point, the second distillation column 190 between the dew point of silicon tetrachloride and the boiling point of trichlorosilane. The operating pressure of the first distillation column 160 and the second distillation column 190 can be about 0 to about 10 bar and the boiling point and dew point of the respective components are determined by the vapor pressure and operating pressure.

[0095] On the other hand, to increase the purity of the hydrogen coming from the first distillation column 160 is derived, a separation membrane 112 be installed and the flowing hydrogen stream 111 can be in whole or in part. Furthermore, the separation membrane 112 separated impurities 113 into a storage tank 180with the distillate from the first distillation column 160 released chlorosilane-based compound 170 mixed and then from the second distillation column 190 transferred.

[0096] Fig. 4 illustrates an exhaust gas purification device according to an embodiment of the present invention.

[0097] In relation to Fig. 4, includes the cleaning device 200 for exhaust gas according to an embodiment of the present invention, a catalytic reactor 203 , a separator 216 , a separation membrane 220 and a distillation column 229 .

[0098] In the catalytic reactor 203 the exhaust gas 202 , which comes from the reactor for the deposition of polysilicon 201 is discharged, is passed on for separation and purification. At this point, the exhaust gas can 202contain more than 50 mol% hydrogen, about 0.01 to about 5 mol% hydrogen chloride, about 0.01 to about 10 mol% dichlorosilane, about 0.01 to about 25 mol% trichlorosilane, and about 0.01 to about 10 mol% silicon tetrachloride, without limitation.

[0099] The catalytic reactor 203 is treated with an ion exchange resin catalyst 204 filled.

[0100] The exhaust 202 is produced by the catalytic reactor 203 which is treated with an ion exchange resin catalyst 204 filled, and within the catalytic reactor 203 Hydrogen chloride can be converted into trichlorosilane and / or silicon tetrachloride according to the reaction formulas 1 and / or 2 described above. The catalytic reactor 203can be operated under temperature conditions of about -40 to about 200°C, preferably about -20 to about 150°C, and more preferably about 0 to about 100°C, without being limited thereto; these can be varied within a range that allows the ion exchange resin catalyst 204 not deactivated.

[0101] In addition, the operating pressure is in the range of about 1 to about 30 bar, preferably about 1 to about 20 bar, and more preferably about 1 to about 10 bar, but can be varied within a range that does not affect the activity of the ion exchange resin catalyst 204 and the operation of the catalytic reactor 203 impaired.

[0102] The catalytic reactor 203 conducted mixed gas 205 is carried out by means of the cooler 215 cooled to below –5°C and then into a separator 216At this time, to facilitate the transport of the mixed gas 205 at the back of the cooler 215 a pump is installed, or the separator 216 is placed at the bottom of the catalytic reactor 203 positioned, allowing gravity-driven flow.

[0103] The mixed gas stream from the separator 216 is converted into a non-condensed phase current 217 containing an excess of hydrogen and a condensed phase stream 225 , which contains an excess of chlorosilane-based compounds, is separated according to the vapor pressure of the respective components. The non-condensed phase stream 217 may contain more than about 80 mol% hydrogen, and the composition of the chlorosilane-based compound within the non-condensed phase stream 217 can be adjusted according to the temperature and pressure of the separator 216The non-condensed phase current 217 is done using a compressor 218 compressed to form the separation membrane 220 to pass through and can be pressurized, for example, with up to about 3 to about 6 bar or more. The pressurized condensed phase stream 219 is converted into high-purity hydrogen, which the separation membrane 220 happened, and impurities 221 that do not pass through the separation membrane 220 Non-permeable contaminants 221 , which is separated by the separation membrane 220 are separated by a liquid separator 222 and again into a hydrogen stream 223 and a chlorosilane-based condensed phase stream 224 separated, whereby the hydrogen stream 223 with the non-condensed phase current 217 , which is located on top of the separator 216is discharged, mixed and passed through the compressor 218 is directed.

[0104] The one at the bottom of the separator 216 derived condensed phase current 225 is used with the chlorosilane-based condensed phase stream 224 , which from the liquid separator 222 released, mixed to produce a chlorosilane-based stream 226 The chlorosilane-based current 226 is pumped 227 to a distillation column 229 At that time, in order to improve the separation efficiency, it is possible to transfer the product to the distillation column 229 also a heater 228 The chlorosilane-based current 226 can be heated by a heater 228 heated to about 30 to about 70°C.

[0105] The distillation column 229 conducted chlorosilane-based current 226is separated into dichlorosilane and trichlorosilane in the gas phase and silicon tetrachloride in the liquid phase and then discharged. At this time, the distillation column can 229 within a pressure range of approximately 3 to approximately 7 bar and between the dew point of silicon tetrachloride and the boiling point of trichlorosilane. The dew point of silicon tetrachloride and the boiling point of trichlorosilane are determined by the operating pressure and vapor pressure of the respective components.

[0106] According to the exhaust gas purification method and apparatus of the present invention as described above, instead of performing the condensation and compression process and implementing boiling point difference separation, hydrogen chloride is removed from the exhaust gas released from the polysilicon deposition reactor by converting it into a chlorosilane-based compound using a catalytic reactor. Thus, energy consumption can be reduced by 40% or more by using the absorption column compared to a conventional exhaust gas purification process.

[0107] Therefore, no hydrogen chloride is released into the environment, and it is possible to prevent several of the problems caused by hydrogen chloride. To remove hydrogen chloride, which has a low boiling point, the uncondensed phase stream containing the hydrogen chloride is cooled and compressed, then re-sprayed and fed to the absorption column, as in the conventional process. This avoids energy consumption inefficiencies and makes it possible to effectively remove hydrogen chloride using a low-energy process.

[0108] According to a further embodiment of the invention, there is provided an exhaust gas purification method comprising the steps of: separating the exhaust gas released after the chemical vapor deposition (CVD) polysilicon deposition process into a non-condensed phase stream and a condensed phase stream; passing the condensed phase stream through a catalytic reactor containing an ion exchange resin catalyst to reduce the hydrogen chloride concentration.

[0109] According to an embodiment of the invention, the exhaust gas released after carrying out a polysilicon deposition process is first separated into a non-condensed gas phase stream and a condensed liquid phase stream.

[0110] In particular, according to one embodiment of the invention, the exhaust gas discharged from a chemical deposition reactor is cooled, then passed into a separator and separated into a non-condensed gas phase stream containing an excess of hydrogen and a condensed liquid phase stream containing an excess of chlorosilane-based compounds.

[0111] The uncondensed gas phase stream separated from the top of the separator is further cooled and pressurized, then injected into the absorption column. The hydrogen contained in the uncondensed phase stream can be released at the top of the absorption column and ultimately purified in the absorption column and recycled. Additionally, hydrogen chloride contained in the uncondensed phase stream is released to the bottom of the absorption column and finally removed by a catalytic reactor, which is described below.

[0112] The condensed liquid phase stream separated from the bottom of the separator is injected into the catalytic reactor containing an ion-exchange resin catalyst. Alternatively, the condensed phase stream separated at the bottom of the separator can be injected into the catalytic reactor containing the ion-exchange resin catalyst by passing the uncondensed phase stream separated at the top of the separator through the absorption column and then mixing it with the liquid phase stream discharged from the absorption column.

[0113] According to an embodiment of the invention, the exhaust gas discharged from a chemical vapor deposition reactor is, after the first cooling, passed into a separator and then separated into a non-condensed gas phase stream containing an excess of hydrogen and a condensed liquid phase containing an excess of chlorosilane-based compounds.

[0114] The uncondensed gas phase stream discharged from the top of the separator is directed to a condenser and subjected to a second cooling at a low temperature. Due to the second low-temperature cooling, additional condensation of hydrogen chloride and chlorosilane, each contained in the uncondensed gas phase stream, is generated, and the condensed stream is recycled to the separator. The uncondensed stream is then injected into the absorption column, and the hydrogen contained in the uncondensed phase stream can be discharged at the top of the absorption column and ultimately purified in the absorption column and recycled. In addition, hydrogen chloride contained in the uncondensed phase stream is discharged to the bottom of the absorption column and finally removed by means of a catalytic reactor, which is described below.

[0115] The liquid-condensed phase stream discharged from the bottom of the separator is injected into the catalytic reactor containing an ion-exchange resin catalyst. Alternatively, it can be mixed with a liquid phase stream discharged from the absorption column and injected into a catalytic reactor containing an ion-exchange resin catalyst.

[0116] By passing the liquid phase stream through the catalytic reactor containing the ion exchange resin catalyst, the hydrogen chloride contained in the liquid-condensed phase stream is removed.

[0117] Suitable ion exchange resin catalysts include a cyclic amine compound, a styrene-based amine-containing polymer, a styrene-divinylbenzene-based amine-containing polymer, an amine-containing acrylic polymer, or mixtures thereof. Examples of possible cyclic amine compounds include vinylpyridine, pyridazine, pyrimidine, pyrazine, piperidine, pyrrolidine, and the like, but the invention is not limited to these.

[0118] A more detailed description of the ion exchange resin catalyst and specific types, mechanism and effects thereof are the same as described above.

[0119] The composition ratio of the respective components contained in the condensed phase stream is not particularly limited; however, according to one embodiment of the present invention, the condensed phase stream injected into the catalytic reactor may contain about 0.01 to about 5 mol% of hydrogen chloride, about 0.01 to about 1 mol% of hydrogen, and a residual amount of the chlorosilane-based compound. On the other hand, for the purpose of more effective hydrogen chloride removal, the number of moles of trichlorosilane may be included in a number greater than 1 mole based on 1 mole of hydrogen chloride (HCl).

[0120] The relative content of hydrogen chloride occupied in the total condensed phase stream can be reduced to about 80 mol% or more, for example about 80 to 100 mol%, preferably about 90 to 99.9 mol%, with respect to the content before passage through the catalytic reactor.

[0121] The step of passing the condensed phase stream through the catalytic reactor containing the ion exchange resin catalyst can be carried out at a temperature of about -40 to about 200°C, preferably about -20 to about 150°C, more preferably about 0 to about 100°C, at a pressure of about 1 to about 30 bar, about 1 to about 20 bar, and even more preferably about 1 to about 10 bar, but is not limited thereto. Within the activation range of the ion exchange resin catalyst, it is possible to change the conditions appropriately.

[0122] According to an embodiment of the invention, after the condensed phase stream has passed through the catalytic reactor containing the ion exchange resin catalyst, a separation process can be carried out to separate the chlorosilane-based compounds contained in the passed phase stream.

[0123] There are no specific restrictions on the use of the separation process, provided the process is a method for separating high-boiling-point compounds from low-boiling-point compounds from the mixture. For example, this can be achieved using a distillation process, a membrane separation process, a gas-liquid separation process, or a combination thereof.

[0124] According to another embodiment of the invention, there is provided an exhaust gas purification device comprising: a separation device that separates the exhaust gas released after the polysilicon deposition process by means of a chemical vapor deposition (CVD) reaction into a non-condensed phase stream and a condensed phase stream; a catalytic reactor containing an ion exchange resin catalyst and reducing the hydrogen chloride concentration in the condensed phase stream.

[0125] In this respect, the description of the catalytic reactor containing the ion exchange resin catalyst and the exhaust gas are the same as in the description of the purification process above.

[0126] The use of the separation device is not particularly limited, as long as it is a conventional device for separating high-boiling-point compounds from low-boiling-point compounds from the mixture. For example, the separation device may include, among others, a separator, a distillation device, a separation membrane device, a gas-liquid separation device, and the like. In addition, the separation device may be installed at the front end of the catalytic reactor and operated in conjunction with different devices and operating conditions depending on the object to be separated.

[0127] In particular, according to one embodiment of the invention, the exhaust gas released from the chemical vapor deposition reactor, after cooling, is passed into a separator and separated into a non-condensed gas phase stream containing an excess of hydrogen and a condensed liquid phase stream containing an excess of chlorosilane-based compounds.

[0128] The uncondensed gas phase stream discharged from the top of the separator is further cooled and pressurized, then injected into the absorption column. The hydrogen contained in the uncondensed phase stream is discharged at the top of the absorption column, then purified in the absorption column and recycled. Additionally, hydrogen chloride contained in the uncondensed phase stream is released to the bottom of the absorption column and finally removed by a catalytic reactor, as described below.

[0129] The liquid phase stream released from the bottom of the separator is mixed with the liquid phase stream released from the absorption column and then injected into the catalytic reactor containing the ion-exchange resin catalyst. In the catalytic reactor containing the ion-exchange resin catalyst, hydrogen chloride is converted to trichlorosilane (SiHCl) using the reaction shown in reaction formulas 1 and / or 2 to reduce the hydrogen chloride concentration. 3 ) and / or silicon tetrachloride (SiCl 4 ). This releases a chlorosilane-based stream with a reduced hydrogen chloride concentration.

[0130] According to a further embodiment of the invention, the exhaust gas released from a chemical vapor deposition reactor is, after cooling, passed into a separator and separated into a non-condensed gas phase stream containing an excess of hydrogen and a condensed liquid phase stream containing an excess of chlorosilane-based compounds.

[0131] The uncondensed gas phase stream released from the top of the separator is directed to a condenser and cooled at a low temperature. Due to the low-temperature cooling, additional condensation of hydrogen chloride and chlorosilane contained in the uncondensed gas phase stream is generated, and the condensed stream is recycled to the separator. The uncondensed phase stream is then injected into the absorption column, and the hydrogen contained in the uncondensed phase stream can be released from the top of the absorption column and ultimately purified in the absorption column and recycled back into the cycle. In addition, hydrogen chloride contained in the uncondensed phase stream is released to the bottom of the absorption column and finally removed by the catalytic reactor.

[0132] The liquid phase stream released from the bottom of the separator is mixed with the liquid phase stream released from the absorption column and then injected into the catalytic reactor containing the ion-exchange resin catalyst. In the catalytic reactor containing the ion-exchange resin catalyst, the hydrogen chloride concentration is reduced by the reaction shown in Reaction Formulas 1 and / or 2, thus releasing a chlorosilane-based stream with a reduced hydrogen chloride concentration. At this time, due to the low-temperature cooling of the stream released from the top of the separator, the amount of hydrogen chloride and chlorosilane in the uncondensed phase stream is reduced. This significantly reduces the recycling flow of the liquid phase chlorosilane to be fed to the absorption column.The remainder is transferred to a second distillation column, separated into di- / trichlorosilane and silicon tetrachloride, and then returned to the cycle.

[0133] An embodiment of the cleaning device according to the invention will now be described in further detail with reference to the accompanying drawings.

[0134] Fig. 5 illustrates an exhaust gas purification device according to an embodiment of the invention.

[0135] With reference to Fig. 5, the cleaning device according to the invention 500 for exhaust gas comprises, according to one embodiment, a catalytic reactor 550 , a separator 515 , an absorption column 525 , an adsorption column 560 and a distillation column 565 on.

[0136] The polysilicon deposition reactor 505 released exhaust gas 501 is in a first cooler510 cooled, then into the separator 515 and into a non-condensed phase stream 502 containing an excess of hydrogen and a condensed phase stream 503 containing an excess of chlorosilane-based compounds. The non-condensed phase stream 502 may contain more than about 80 mol% hydrogen, and the composition of the chlorosilane-based compounds within the non-condensed phase stream 502 can depend on the temperature and pressure of the separator 515 be determined.

[0137] The one from the top of the separator 515 released non-condensed gas phase stream 502 After further cooling and further pressurization, it is transferred to an absorption column 525 The hydrogen contained in the non-condensed phase stream 502 is at this time at the top of the absorption column525 released and finally in the absorption column 560 cleaned and returned to the cycle. In addition, hydrogen chloride, which is present in the non-condensed phase stream 502 contained, to the lower end of the absorption column 525 released and using the catalytic reactor 550 permanently removed as described below.

[0138] The one at the bottom of the separator 515 released condensed phase current 503 is pumped 570 with a from the bottom of the absorption column 525 released liquid phase stream 506 mixed and fed into a catalytic reactor 550 At this time, a mixed flow of the condensed phase flow 503 and the liquid phase flow 506about 0.01 to about 1 mol% hydrogen, about 0.01 to about 5 mol% hydrogen chloride, about 0.01 to about 10 mol% dichlorosilane, about 0.01 to about 80 mol% trichlorosilane, and about 0.01 to about 50 mol% silicon tetrachloride, but is not limited thereto.

[0139] The mixed current of the condensed phase current 503 and the liquid phase flow 506 is produced by the catalytic reactor 550 , which is mixed with the ion exchange resin catalyst 555 filled, and it is possible to produce hydrogen chloride according to formulas 1 and 2 described above in the catalytic reactor 550 to trichlorosilane or silicon tetrachloride. The catalytic reactor 550can be operated at temperature conditions of about -40 to about 200°C, preferably at about -20 to about 150°C and more preferably at 0 to about 100°C, but is not limited thereto and can be operated within the range in which the ion exchange resin catalyst 555 is not deactivated.

[0140] Furthermore, the operating pressure is in the range of about 1 to about 30 bar, preferably about 1 to about 20 bar, and more preferably about 1 to about 10 bar, but may be within the range that does not affect the activity of the ion exchange resin catalyst 555 and the operation of the catalytic reactor 550 has, be changed.

[0141] Unlike a conventional purification process that uses a distillation column instead of a catalytic reactor 550contains, the above step converts hydrogen chloride into chlorosilane-based compounds and thus no gaseous hydrogen chloride is released.

[0142] Part of the chlorosilane-based liquid phase stream 507 , which comes from the bottom of the catalytic reactor 550 is released, is passed through a cooler 530 to an absorption column 525 transferred and used to remove hydrogen chloride and chlorosilane-based compounds in the non-condensed phase stream 502 to absorb, and the rest becomes a distillation column 565 transferred to the distillation column 565 conducted chlorosilane-based current 507 is separated into dichlorosilane and trichlorosilane in the gas phase and silicon tetrachloride in the liquid phase and then released. At this time, the distillation column 556within a pressure range of approximately 3 to approximately 7 bar and between the dew point of silicon tetrachloride and the boiling point of trichlorosilane. The dew point of silicon tetrachloride and the boiling point of trichlorosilane are determined by the operating pressure and vapor pressure of the respective components.

[0143] Fig. 6 illustrates an exhaust gas purification device according to an embodiment of the invention.

[0144] With reference to Fig. 6, the cleaning device 600 for exhaust gas according to an embodiment of the present invention comprises a catalytic reactor 650 , a separator 615 , an absorption column 625 , an adsorption column 660 and a distillation column 665 .

[0145] The exhaust gas discharged from the polysilicon deposition reactor 601 is in a first cooler 610cooled and then a separator 615 and converted into a non-condensed phase current 602 containing excess hydrogen and a condensed phase stream 603 , which contains excess chlorosilane-based compounds. The non-condensed phase stream 602 may contain more than about 80 mol% hydrogen, and the composition of the chlorosilane-based compounds in the non-condensed phase stream 602 can be determined based on the temperature and pressure of the separator 615 be determined.

[0146] The non-condensed phase current 602 , which is discharged from the top of the separator 615 is discharged into a second cooler 620and cooled to a low temperature. The cooler can be operated at this time at a temperature of approximately -30 to approximately -70°C, preferably at approximately -40 to approximately -60°C. Due to the cooling to a low temperature, further condensation of the hydrogen chloride and the chlorosilane in the non-condensed phase stream occurs. 602 and the condensed liquid stream is fed to the separator 615 Subsequently, the non-condensed product from the absorption column 625 injected phase current 602 contained hydrogen chloride to the bottom of the absorption column 625 and finally via the absorption column 650 which is described below. The hydrogen flow 604 , which is discharged from the top of the absorption column 625 is finally collected in the absorption column 660cleaned and returned to the cycle.

[0147] The condensed phase current 603 which is at the bottom of the separator 615 is mixed with a liquid phase stream 606 , which is located at the bottom of the absorption column 625 using a pump 670 and into a catalytic reactor 650 At this point, the mixed stream from the condensed phase stream 603 and the liquid flow 606 about 0.01 to 1 mol% hydrogen, about 0.01 to about 5 mol% hydrogen chloride, about 0.01 to about 10 mol% dichlorosilane, about 0.01 to about 80 mol% trichlorosilane, and about 0.01 to about 50 mol% silicon tetrachloride, without being limited to these amounts.

[0148] The mixed current from the condensed phase current 603 and the liquid phase flow 606 flows through the catalytic reactor 650, which is mixed with the ion exchange resin catalyst 655 filled, and in the catalytic reactor 650 Hydrogen chloride can be converted to trichlorosilane and / or silicon tetrachloride according to the reaction formulas 1 and / or 2 described above. The catalytic reactor 650 can be operated under temperature conditions of about -40 to about 200°C, preferably at about -20 to about 150°C and more preferably at about 0 to about 100°C, but is not limited to these temperatures, but the temperatures can be changed within a range in which the ion exchange resin catalyst 655 is not deactivated.

[0149] In addition, the operating pressure is in the range of about 1 to about 30 bar, preferably about 1 to about 20 bar, and more preferably about 1 to about 10 bar, but can be varied within a range that affects the activity of the ion exchange resin catalyst 655and the operation of the catalytic reactor 650 not affected.

[0150] Unlike a conventional purification process, which uses a catalytic reactor instead of 650 comprises a distillation column, in the step described above, hydrogen chloride is converted into a chlorosilane-based compound so that no gaseous hydrogen chloride is released.

[0151] Part of the chlorosilane-based liquid phase stream 607 , which is located at the bottom of the catalytic reactor 650 is discharged to an absorption column 625 and used to absorb hydrogen chloride and chlorosilane-based compounds in the non-condensed phase stream. At this point, the non-condensed phase stream is 602 , which is discharged from the top of the separator 615is discharged, in a state in which the amount of hydrogen chloride and chlorosilane-based compounds is reduced by additional cooling to low temperature with a second cooler 620 is significantly reduced. The chlorosilane-based liquid phase stream recycled to the absorption column 625 to be transported can therefore be used to reduce to a range of about 30 to 90%, and preferably to a range of about 50 to 80%.

[0152] The residual stream is sent to the distillation column 665 The distillation column 665 guided chlorosilane-based current 607 is separated into gaseous dichlorosilane and trichlorosilane and liquid silicon tetrachloride and then discharged. At this point, the distillation column can 665within the pressure range of approximately 3 to approximately 7 bar and between the dew point of silicon tetrachloride and the boiling point of trichlorosilane. The dew point of silicon tetrachloride and the boiling point of trichlorosilane are determined by the operating pressure and the vapor pressure of the respective components.

[0153] According to another embodiment of the present invention, there is provided a purification method for exhaust gas comprising the following steps: Separating the exhaust gas discharged after performing a polysilicon deposition process by chemical vapor deposition (CVD) into a non-condensed phase stream and a condensed phase stream; Passing the uncondensed phase stream through a first catalytic reactor to reduce the hydrogen chloride concentration; and Separation of a chlorosilane-based compound from the condensed phase stream according to the boiling point.

[0154] In the purification method according to another embodiment of the present invention, the exhaust gas discharged after performing a polysilicon deposition process is first condensed to separate into a non-condensed gas phase stream and a condensed liquid phase stream (first condensation and separation step). At this time, the non-condensed phase stream may contain an excess of hydrogen, and the condensed phase stream may contain an excess of a chlorosilane-based compound. Hydrogen chloride may also be relatively more dispersed in the non-condensed phase stream than in the condensed phase stream.

[0155] The first condensation can be carried out at a temperature above about -30°C and below about 10°C, preferably above about -20°C and below about 5°C, and more preferably above about -10°C and below about 0°C. When the condensation is carried out within the above-mentioned temperature range, effective separation into a stream containing excess hydrogen and a stream containing excess chlorosilane-based compound can be achieved. If the condensation is carried out at a temperature of -30°C or lower, the contents of dichlorosilane and trichlorosilane are relatively low, and effective removal of hydrogen chloride becomes difficult. If the condensation is carried out at a temperature above 10°C, the content of the chlorosilane-based compound in the non-condensed phase stream increases, thereby increasing the process cost, which is undesirable.

[0156] The uncondensed gas phase stream is injected into a first catalytic reactor, and in the first catalytic reactor, hydrogen chloride can be converted into a chlorosilane-based compound (catalytic reaction stage).

[0157] The uncondensed gas phase stream may undergo a pressurization stage prior to injection into the first catalytic reactor to bring the pressure reduced in the first condensation stage to a suitable level before entering the first catalytic reactor (compression stage). According to one embodiment of the present invention, the uncondensed gas phase stream may be brought to a specific pressure, which should be between about 1 to about 50 bar, preferably about 1 to about 40 bar, and even more preferably about 1 to about 30 bar.

[0158] According to one embodiment of the present invention, the first catalytic reactor may comprise an ion exchange resin catalyst.

[0159] Cyclic amine compounds, styrene-based polymers containing an amine group, styrene-divinylbenzene-based polymers containing an amine group, acrylic polymers containing an amine group, or mixtures thereof can be used as the ion exchange resin catalyst. Examples of cyclic amine compounds include vinylpyridine, pyridazine, pyrimidine, pyrazine, piperidine, pyrrolidine, and similar compounds, but the invention is not limited to these.

[0160] A more detailed description of the ion exchange resin catalyst, its specific types, mechanisms and effects can be found in the description above.

[0161] According to one embodiment of the present invention, the first catalytic reactor may comprise an amine-based compound. Examples of amine-based compounds include amine, ammonium salt, aminosilane, aminosiloxane, aminoalkoxysilane, or similar compounds, but the invention is not limited to these.

[0162] According to another embodiment of the present invention, the first catalytic reactor may comprise a transition metal catalyst. Examples of transition metal catalysts include platinum, palladium, ruthenium, nickel, iridium, rhodium, or similar metals, as well as metal oxides, metal hydrides, organometallic compounds, and complex metal oxides, but the present invention is not limited to these. According to one embodiment of the present invention, the transition metal catalyst may preferably consist of palladium (Pd) or platinum (Pt).

[0163] The amine-based compound or the transition metal catalyst may further preferably be bonded to or supported on a support. There are no particular restrictions on the support, except that it must generally be suitable as a support for an amine-based compound or a transition metal. Preferably, the support may be made of carbon, for example, activated carbon, a carbon nanotube, a carbon nanoribbon, a carbon nanowire, porous carbon, carbon powder, or carbon black, and an inorganic support such as silicon dioxide (SiO 2 ) or aluminum oxide (Al 2 O 3 ) consist.

[0164] According to a further embodiment of the present invention, the first catalytic reactor may comprise an activated carbon catalyst.

[0165] In the non-condensed phase stream passed through the first catalytic reactor, hydrogen chloride is converted into a chlorosilane-based compound, and thus the concentration of hydrogen chloride can be significantly reduced by about 80 mol% or more, for example, about 80 to about 100 mol%, preferably about 90 to about 99.9 mol%, compared to the concentration before flowing through the first catalytic reactor.

[0166] The uncondensed phase stream with a lower hydrogen chloride concentration is then subjected to a second condensation and separated into a hydrogen stream and a chlorosilane-based stream (second condensation and separation stage). The hydrogen stream separated during the second condensation can be passed on to the adsorption process and ultimately purified and recycled (adsorption stage). The chlorosilane-based stream separated after the second condensation can be reinjected into the first condensation and separation stage and recycled.

[0167] On the other hand, the condensed phase stream from the first condensation and separation stage can be transferred to the distillation stage, separated into di- / trichlorosilane and silicon tetrachloride and returned to the cycle (distillation stage).

[0168] According to one embodiment of the present invention, a hydrogen chloride distillation step may also be performed prior to the distillation step to remove a small amount of hydrogen chloride contained in the condensed phase stream. Alternatively, the stream may be passed through the catalytic reactor separately.

[0169] Furthermore, according to an embodiment of the present invention, the chlorosilane-based stream separated after the second condensation may be combined with the condensed phase stream derived in the first condensation and separation stage or injected individually into the distillation stage.

[0170] As described above, a distillation step or a second catalytic reaction step is carried out before separating the condensed phase stream derived from the first condensation and separation stage into di- / trichlorosilane and silicon tetrachloride, thereby further reducing the hydrogen chloride content in the entire circulating stream.

[0171] The second catalytic reactor, used to remove hydrogen chloride from the condensed phase stream, may contain a catalyst, such as an ion exchange resin, an amine-based compound, or a transition metal, which may be the same or different from that used in the first catalytic reactor. The first and second catalytic reactors may be operated under separate conditions.

[0172] The exhaust gas purification method according to an embodiment of the present invention will be described in more detail with reference to the accompanying drawings.

[0173] Fig. 7 and Fig. 8 shows a flowchart of an exhaust gas purification method according to an embodiment of the present invention.

[0174] With reference to the Fig. 7 and Fig. 8, the purification method for exhaust gas according to an embodiment of the present invention comprises a first condensation and separation step (S10), a compression step (S20), a catalytic reaction step (S30), a second condensation and separation step (S40), an adsorption step (S50), and a distillation step (S60).

[0175] With reference to Fig.7, the exhaust gas discharged from the vapor deposition reactor is separated in the first condensation and separation stage (S10) into a non-condensed gas phase stream containing excess hydrogen and a condensed liquid phase stream containing excess chlorosilane-based compounds.

[0176] The uncondensed gas phase stream discharged from the first condensation and separation stage (S10) is injected into a catalytic reaction stage (S30) after a compression stage (S20). At this point, the hydrogen chloride contained in the uncondensed phase stream is converted to trichlorosilane and silicon tetrachloride in the catalytic reaction stage (S30), thereby reducing the hydrogen chloride concentration.

[0177] The uncondensed phase stream passing through the catalytic reaction stage (S30) is passed on to the second condensation and separation stage (S40). The hydrogen derived from the second condensation and separation stage (S40) can finally be purified in the adsorption stage (S50) and recycled. Furthermore, the condensed liquid phase stream, which has a lower hydrogen chloride concentration and is derived from the second condensation and separation stage (S40), can be combined with the condensed phase stream derived from the first distillation stage (S10) and injected into the distillation stage (S60).

[0178] The stream passed on to the distillation stage (S60) can be separated into di- / trichlorosilane and silicon tetrachloride and then returned to the cycle.

[0179] With reference to Fig. 8, is, similar to Fig.7, the exhaust gas discharged from the vapor deposition reactor is separated in the first condensation and separation stage (S10) into a non-condensed gas phase stream containing excess hydrogen and a condensed liquid phase stream containing excess chlorosilane-based compounds.

[0180] The uncondensed gas phase stream discharged from the first condensation and separation stage (S10) is injected into a catalytic reaction stage (S30) after a compression stage (S20). At this point, the hydrogen chloride contained in the uncondensed phase stream is converted to trichlorosilane and silicon tetrachloride in the catalytic reaction stage (S30), thereby reducing the hydrogen chloride concentration.

[0181] The uncondensed phase stream, which passed through the catalytic reaction stage (S30), is passed on to the second condensation and separation stage (S40). The hydrogen derived from the second condensation and separation stage (S40) can finally be purified in the adsorption stage (S50) and recycled. Furthermore, the condensed liquid phase stream, which has a lower hydrogen chloride concentration and is derived from the second condensation and separation stage (S40), can be passed on to the first distillation stage (S10) and recycled.

[0182] Separately, the condensed phase stream derived from the first condensation and separation stage (S10) can be passed on to the distillation stage (S60), separated into di- / trichlorosilane and silicon tetrachloride and returned to the cycle.

[0183] Fig. 9 and Fig.11 shows a flowchart of an exhaust gas purification method according to an embodiment of the present invention.

[0184] With reference to the Fig. 9 and Fig. 11, the purification method for exhaust gas according to an embodiment of the present invention includes a first condensation and separation step (S110), a compression step (S120), a catalytic reaction step (S130), a second condensation and separation step (S140), an adsorption step (S150), a first distillation step (S160), and a second distillation step (S170).

[0185] With reference to Fig. 9, the exhaust gas discharged from the vapor deposition reactor is separated in the first condensation and separation stage (S10) into a non-condensed gas phase stream containing excess hydrogen and a condensed liquid phase stream containing excess chlorosilane-based compounds.

[0186] The uncondensed gas phase stream discharged from the first condensation and separation stage (S110) is injected into a catalytic reaction stage (S130) after the compression stage (S120). At this point, the hydrogen chloride contained in the uncondensed phase stream is converted to trichlorosilane and silicon tetrachloride in the catalytic reaction stage (S130), thereby reducing the hydrogen chloride concentration.

[0187] The non-condensed phase stream passed through the catalytic reaction stage (S130) is forwarded to the second condensation and separation stage (S140). The hydrogen discharged from the second condensation and separation stage (S140) can finally be purified in the adsorption stage (S150) and recycled. Additionally, hydrogen chloride contained in the non-condensed gas phase stream discharged from the first condensation and separation stage (S110) can be separated separately in the first distillation stage (S160) and recycled back to the first condensation and separation stage (S110).

[0188] The condensed liquid phase stream, which has a lower hydrogen chloride concentration and is discharged from the second condensation and separation stage (S140), can be combined with the condensed phase stream discharged from the first condensation and separation stage (S110) and then injected into the first distillation stage (S160). In the first distillation stage (S160), a hydrogen chloride gas phase stream and a chlorosilane-based liquid phase stream are separated.

[0189] The chlorosilane-based stream derived from the first distillation stage (S160) can be passed on to the second distillation stage (S170), separated into di- / trichlorosilane and silicon tetrachloride, and recycled.

[0190] With reference to Fig. 10, similar to Fig.9, the exhaust gas discharged from the vapor deposition reactor is separated in the first condensation and separation stage (S110) into a non-condensed gas phase stream containing excess hydrogen and a condensed liquid phase stream containing excess chlorosilane-based compounds.

[0191] The uncondensed gas phase stream discharged from the first condensation and separation stage (S110) is injected into a catalytic reaction stage (S130) after the compression stage (S120). At this point, the hydrogen chloride contained in the uncondensed phase stream is converted to trichlorosilane and silicon tetrachloride in the catalytic reaction stage (S130), thereby reducing the hydrogen chloride concentration.

[0192] The uncondensed phase stream, which has passed through the catalytic reaction stage (S130), is forwarded to the second condensation and separation stage (S140). The hydrogen derived from the second condensation and separation stage (S140) can finally be purified in the adsorption stage (S150) and recycled.

[0193] In addition, hydrogen chloride contained in the non-condensed gas phase stream discharged from the first condensation and separation stage (S110) can be separated separately from the chlorosilane-based streams in the first distillation stage (S160) and recycled back to the first condensation and separation stage (S110).

[0194] The condensed liquid phase stream, which has a lower hydrogen chloride concentration and is discharged from the second condensation and separation stage (S140), can be combined with the condensed phase stream discharged from the first condensation and separation stage (S160) and then injected into the first distillation stage (S170). In the first distillation stage (S160), a hydrogen chloride gas phase stream and a chlorosilane-based liquid phase stream are separated.

[0195] The second stream forwarded to the distillation stage (S170) can be separated into di- / trichlorosilane and silicon tetrachloride and then recycled.

[0196] With reference to Fig. 11, similar to Fig.9, the exhaust gas discharged from the vapor deposition reactor is separated in the first condensation and separation stage (S110) into a non-condensed gas phase stream containing excess hydrogen and a condensed liquid phase stream containing excess chlorosilane-based compounds.

[0197] The uncondensed gas phase stream from the first condensation and separation stage (S110) is injected into a catalytic reaction stage (S130) after the compression stage (S120). At this point, the hydrogen chloride contained in the uncondensed phase stream is converted to trichlorosilane and silicon tetrachloride in the catalytic reaction stage (S130), thereby reducing the hydrogen chloride concentration. The uncondensed phase stream, which has passed through the catalytic reaction stage (S130), is passed on to the second condensation and separation stage (S140). The hydrogen derived from the second condensation and separation stage (S140) can finally be purified in the adsorption stage (S150) and recycled.In addition, hydrogen chloride contained in the condensed gas phase stream discharged from the first condensation and separation stage (S110) can be separated separately from the chlorosilane-based streams in the first distillation stage (S160) and recycled back to the first condensation and separation stage (S110).

[0198] On the other hand, the condensed liquid phase stream having a lower hydrogen chloride concentration and discharged from the second condensation and separation stage (S40) can also be injected into the first condensation and separation stage (S110) and circulated.

[0199] The condensed liquid phase stream, which has a lower hydrogen chloride concentration and is discharged from the first condensation and separation stage (S110), can be passed on to the first distillation stage (S160) and separated into hydrogen chloride- and chlorosilane-based streams. The chlorosilane-based stream discharged from the first distillation stage (S160) is passed on to the second distillation stage (S170), separated into di- / trichlorosilane and silicon tetrachloride, and then recycled.

[0200] Fig. 12 and Fig. 14 shows a flowchart of an exhaust gas purification method according to an embodiment of the present invention.

[0201] With reference to the Fig. 12 and Fig.14, the purification method for exhaust gas according to an embodiment of the present invention includes a first condensation and separation step (S210), a compression step (S220), a first catalytic reaction step (S230), a second condensation and separation step (S240), an adsorption step (S250), a second catalytic reaction step (S260), and a distillation step (S270).

[0202] With reference to Fig. 12, first, the exhaust gas discharged from the vapor deposition reactor is separated in the first condensation and separation stage (S210) into a non-condensed gas phase stream containing excess hydrogen and a condensed liquid phase stream containing excess chlorosilane-based compounds.

[0203] The uncondensed gas phase stream discharged from the first condensation and separation stage (S210) is injected into a catalytic reaction stage (S230) after the compression stage (S220). At this point, the hydrogen chloride contained in the uncondensed phase stream is converted to trichlorosilane and silicon tetrachloride in the first catalytic reaction stage (S230), thereby reducing the hydrogen chloride concentration.

[0204] The uncondensed phase stream, which passed through the catalytic reaction stage (S230), is forwarded to the second condensation and separation stage (S240). The hydrogen derived from the second condensation and separation stage (S240) can finally be purified in the adsorption stage (S250) and recycled.

[0205] In addition, hydrogen chloride contained in the condensed phase stream discharged from the first condensation and separation stage (S210) can be separately converted to trichlorosilane and silicon tetrachloride in the first distillation stage (S260), thereby decreasing the hydrogen chloride concentration.

[0206] The condensed liquid phase stream, which has a lower hydrogen chloride concentration and is discharged from the second condensation and separation stage (S240), can be combined with the condensed phase stream discharged from the first condensation and separation stage (S210) and then injected into the second catalytic reaction stage (S260). In the second catalytic reaction stage (S260), hydrogen chloride is converted to trichlorosilane and silicon tetrachloride, as described above, and a chlorosilane-based stream is separated from it.

[0207] The chlorosilane-based stream derived from the second catalytic reaction stage (S260) can be passed on to the distillation stage (S270), separated into di- / trichlorosilane and silicon tetrachloride, and recycled.

[0208] With reference to Fig. 13, similar to Fig. 12, first, the exhaust gas discharged from the vapor deposition reactor is separated in the first condensation and separation stage (S210) into a non-condensed gas phase stream containing excess hydrogen and a condensed liquid phase stream containing excess chlorosilane-based compounds.

[0209] The uncondensed gas phase stream discharged from the first condensation and separation stage (S210) is injected into the first catalytic reaction stage (S230) after the compression stage (S220). At this point, the hydrogen chloride contained in the uncondensed phase stream is converted to trichlorosilane and silicon tetrachloride in the catalytic reaction stage (S230), thereby reducing the hydrogen chloride concentration.

[0210] The uncondensed phase stream passing through the first catalytic reaction stage (S230) is forwarded to the second condensation and separation stage (S240). The hydrogen derived from the second condensation and separation stage (S240) can finally be purified in the adsorption stage (S250) and recycled.

[0211] In addition, hydrogen chloride contained in the non-condensed gas phase stream discharged from the first condensation and separation stage (S210) can be separately converted to trichlorosilane and silicon tetrachloride in the second catalytic reaction stage (S260), thereby decreasing the hydrogen chloride concentration.

[0212] On the other hand, the condensed liquid phase stream having a lower hydrogen chloride concentration and derived from the second condensation and separation stage (S240) may be combined with the condensed phase stream derived from the second catalytic reaction stage (S260) and then injected into the distillation stage (S270).

[0213] The stream forwarded to the distillation stage (S270) can be separated into di- / trichlorosilane and silicon tetrachloride and then recycled.

[0214] Next, with reference to Fig. 14, similar to Fig. 12, the exhaust gas discharged from the vapor deposition reactor is separated in the first condensation and separation stage (S210) into a non-condensed gas phase stream containing excess hydrogen and a condensed liquid phase stream containing excess chlorosilane-based compounds.

[0215] The uncondensed gas phase stream discharged from the first condensation and separation stage (S210) is injected into the first catalytic reaction stage (S230) after the compression stage (S220). At this point, the hydrogen chloride contained in the uncondensed phase stream is converted to trichlorosilane and silicon tetrachloride in the first catalytic reaction stage (S230), thereby reducing the hydrogen chloride concentration.

[0216] The uncondensed phase stream, which passed through the catalytic reaction stage (S230), is forwarded to the second condensation and separation stage (S240). The hydrogen derived from the second condensation and separation stage (S240) can finally be purified in the adsorption stage (S250) and recycled.

[0217] On the other hand, the condensed liquid phase stream having a lower hydrogen chloride concentration and discharged from the second condensation and separation stage (S240) can be re-injected into the first condensation and separation stage (S210) and then recycled into the cycle.

[0218] In addition, the condensed phase stream discharged from the first condensation and separation stage (S210) is separately forwarded to the second catalytic reaction stage (S260). At this point, the hydrogen chloride contained in the condensed phase stream is converted to trichlorosilane and silicon tetrachloride in the second catalytic reaction stage (S260), thereby reducing the hydrogen chloride concentration. The chlorosilane-based stream, which has a lower hydrogen chloride concentration and is discharged from the second catalytic reaction stage (S260), can be forwarded to the distillation stage (S270), separated into di- / trichlorosilane and silicon tetrachloride, and then recycled.

[0219] The mixing ratio of the components contained in the condensed or uncondensed phase stream is not particularly limited, but according to one embodiment of the present invention, the uncondensed phase stream to be injected into the first catalytic reaction stage may contain about 0.01 to about 5 mol% of hydrogen chloride, about 80 to about 99 mol% of hydrogen, and the remaining amount of the chlorosilane-based compound. On the other hand, for more effective removal of hydrogen chloride, the number of moles of the chlorosilane-based compound may be more than 1 mole relative to 1 mole of hydrogen chloride (HCl).

[0220] The step of passing the uncondensed phase in the first catalytic reaction stage can be carried out at a temperature of about -40 to about 400°C, preferably about -20 to about 300°C, more preferably about 0 to about 200°C, at a pressure of about 1 to about 50 bar, preferably about 1 to about 40 bar, more preferably about 1 to about 30 bar, but not limited thereto. The conditions can be appropriately changed as long as they are within the range in which the catalyst used in the first catalytic reaction stage is activated.On the other hand, according to the exhaust gas purification process of the present invention, the first catalytic reaction step can be carried out under temperature and pressure conditions that have significantly lower energy consumption than the conventional absorption column method for hydrogen chloride removal, thereby significantly reducing energy consumption. However, the hydrogen chloride removal efficiency is equal to or better than that of the absorption column method, thereby improving productivity and reducing the overall cost of the exhaust gas purification process.

[0221] According to one embodiment of the present invention, the condensed phase stream to be injected in the second catalytic reaction stage may contain about 0.01 to about 5 mol% hydrogen chloride, about 0.01 to about 1 mol% hydrogen, and a balance of a chlorosilane-based compound. Alternatively, for more effective hydrogen chloride removal, the number of moles of the chlorosilane-based compound may be greater than 1 mole per mole of hydrogen chloride (HCl).

[0222] The step of passing the condensed phase stream through the second catalytic reaction stage can be carried out at a temperature of about -40 to about 400°C, preferably about -20 to about 300°C, more preferably about 0 to about 200°C, at a pressure of about 1 to about 50 bar, preferably about 1 to about 40 bar, more preferably about 1 to about 30 bar, but not limited thereto. The conditions can be appropriately varied as long as they are within the range in which the catalyst used in the second catalytic reaction stage is activated.

[0223] The relative content of hydrogen chloride in the total condensed or uncondensed phase streams can be reduced to about 50 mol% or more, for example to about 50 to about 99.9 mol%, preferably about 80 to 99.9 mol%, more preferably about 90 to 100 mol%, based on the content before passing through the first and second catalytic reaction stages.

[0224] The operation and effect of the present invention will be described in more detail below with reference to specific examples of the invention. However, these examples are for illustrative purposes only and should not be construed as limiting the scope of the present invention to these examples. <beispiel>Preparation and performance evaluation of a catalytic reactor Preparation example 1

[0225] A catalytic reactor filled with an ion exchange resin catalyst was prepared and the performance of the catalytic reactor was evaluated by gas chromatography.

[0226] An ion exchange resin catalyst with aminated polystyrene-divinylbenzene as matrix with a diameter of 490 to 690 µm (product name: Amberlyst ® A-21) was charged into the 12.7 mm (1 / 2 inch) outer diameter stainless steel tubular reactor. Via a separately connected line, the catalyst was purged with ethanol at three times the volume of the catalyst bed for 1 hour and then purged again with toluene at three times the volume of the catalyst bed for 1 hour to remove any impurities and moisture from the catalyst. Finally, the catalyst was purged with silicon tetrachloride at three times the volume of the catalyst bed to remove any residual solvent.

[0227] Hydrogen was introduced into a trichlorosilane solution obtained by dissolving hydrogen chloride in the catalytic reactor prepared as described above at 100 ml per minute, thus gasifying the trichlorosilane solution in the reactor. At this time, the temperature was maintained at 100°C and the pressure at 2 bar to prevent the trichlorosilane from condensing. Afterward, the reaction residence time under the conditions described above was approximately 10 seconds. The composition of the trichlorosilane gas released by hydrogen was analyzed by gas chromatography via a bypass line before the catalytic reaction, and it was confirmed that approximately 5 mol% of hydrogen chloride was present relative to the trichlorosilane.

[0228] The results of the analysis of the gas composition after the reaction under the condition described above are shown below in Table 1. Preparation example 2

[0229] Trichlorosilane solution, obtained by dissolving hydrogen chloride into the catalytic reactor from Preparatory Example 1, was fed into the reactor at 10 ml per minute. The temperature was maintained at 50°C and the pressure at 10 bar by pressurizing with hydrogen. The void volume of the catalyst bed was 65%, and the reaction residence time under the reaction conditions was 13.5 seconds. The composition of the trichlorosilane solution in which the hydrogen chloride was dissolved was analyzed by gas chromatography via a bypass line before the catalytic reaction, confirming that approximately 2 mol% of hydrogen chloride was present relative to the trichlorosilane.

[0230] The results of the analysis of the gas composition after the reaction under the condition described above are shown below in Table 1. Preparation example 3

[0231] The exhaust gas purification effect of the catalytic reactor containing an activated carbon-supported platinum (Pt) catalyst was confirmed.

[0232] The catalytic reactor was prepared using a 50 cm long stainless steel tube with an outer diameter of 12.7 mm (1 / 2 inch). This reactor was filled with 1.65 g of a carbon-based 0.5 wt% platinum catalyst and then activated at 200°C for 1 hour under a nitrogen stream. A granular catalyst was used (Alfa Aesar).

[0233] When injecting the reaction gas, a method was used to inject hydrogen into a container containing liquid trichlorosilane to cause vaporization, and anhydrous hydrogen chloride was added and mixed just before flow into the reactor. Hydrogen was injected at approximately 100 ml / min, and hydrogen chloride was injected at approximately 30 ml / min. The molar ratio of hydrogen chloride to trichlorosilane was approximately 1:1.4.

[0234] The reactor temperature was set to 150°C and the pressure to 1 bar. The results of the gas composition analysis after the reaction under the above-described conditions are presented below in Table 1. Preparation example 4

[0235] The exhaust gas purification effect of the catalytic reactor containing activated carbon was confirmed.

[0236] The catalytic reactor was prepared using a 50 cm long stainless steel tube with an outer diameter of 12.7 mm (1 / 2 inch). This reactor was filled with 1.65 g of granular activated carbon (size 2 mm or less, Alfa Aesar). Activation was carried out in the same manner as described in Preparation Example 3.

[0237] The reaction condition was set as in Preparatory Example 3. The results of the gas composition analysis after the reaction under the above-described condition are shown below in Table 1. Preparation example 5

[0238] The exhaust gas purification effect of the catalytic reactor containing an activated carbon-supported platinum (Pt) catalyst was confirmed.

[0239] The catalytic reactor was prepared using a 50 cm long stainless steel tube with an outer diameter of 12.7 mm (1 / 2 inch). This reactor was filled with 1.6 g of granular activated carbon-based 0.5 wt% platinum catalyst (Alfa Aesar). Activation was carried out in the same manner as described in Preparation Example 3.

[0240] The reaction condition was set as in Preparatory Example 3. The results of the gas composition analysis after the reaction under the above-described condition are shown below in Table 1. Preparation example 6

[0241] The exhaust gas purification effect of the catalytic reactor containing an activated carbon-supported platinum (Pt) catalyst was confirmed.

[0242] The catalytic reactor was prepared using a 50 cm long stainless steel tube with an outer diameter of 12.7 mm (1 / 2 inch). This reactor was filled with 1.6 g of a 0.5 wt% platinum (Pt) catalyst based on activated carbon. Activation was carried out in the same manner as described in Preparation Example 3.

[0243] The reaction condition was set at 80°C, and the injection of the remaining reaction gas and other reaction conditions were set in the same manner as in Preparation Example 3. The results of the analysis of the gas composition after the reaction under the above-described condition are shown below in Table 1. Preparation example 7

[0244] The reaction was carried out in the same manner as in Preparatory Example 6, except that this reactor was charged with 1.6 g of granular activated carbon-based 0.5 wt% palladium (Pd) catalyst and used. Preparation example 8

[0245] The catalytic reactor and activation were prepared in the same manner as described in Preparation Example 6.

[0246] When injecting the reaction gas, a method was used to inject hydrogen into a container containing liquid trichlorosilane to cause vaporization, and anhydrous hydrogen chloride was added and mixed just before flow into the reactor. Hydrogen was injected at approximately 200 ml / min, and hydrogen chloride was injected at approximately 15 ml / min. The molar ratio of hydrogen chloride to trichlorosilane was approximately 1:2.4.

[0247] The reactor temperature was set to 80°C and the pressure to 1 bar. The results of the gas composition analysis after the reaction under the above-described conditions are presented below in Table 1. Preparation example 9

[0248] The catalytic reactor and activation were prepared in the same manner as described in Preparation Example 7.

[0249] When injecting the reaction gas, a method was used to inject hydrogen into a container containing liquid trichlorosilane to cause vaporization, and anhydrous hydrogen chloride was added and mixed just before flow into the reactor. Hydrogen was injected at approximately 200 ml / min, and hydrogen chloride was injected at approximately 15 ml / min. The molar ratio of hydrogen chloride to trichlorosilane was approximately 1:2.4.

[0250] The reactor temperature was set to 80°C and the pressure to 1 bar. The results of the gas composition analysis after the reaction under the above-described conditions are presented below in Table 1. Preparation example 10

[0251] The catalytic reactor and activation were prepared in the same manner as described in Preparation Example 7.

[0252] When injecting the reaction gas, a method was used to inject hydrogen into a container containing liquid trichlorosilane to cause vaporization, and anhydrous hydrogen chloride was added and mixed just before flow into the reactor. Hydrogen was injected at approximately 200 ml / min, and hydrogen chloride was injected at approximately 15 ml / min. The molar ratio of hydrogen chloride to trichlorosilane was approximately 1:2.4.

[0253] The reactor temperature was set to 80°C and the pressure to 1 bar. The results of the gas composition analysis after the reaction under the above-described conditions are presented below in Table 1. Preparation example 11

[0254] The exhaust gas purification effect of the catalytic reactor containing an activated carbon-supported platinum (Pt) catalyst was confirmed.

[0255] The catalytic reactor was prepared using a 50 cm long stainless steel tube with an outer diameter of 12.7 mm (1 / 2 inch). This reactor was filled with 1.6 g of granular activated carbon-based 2.0 wt% platinum (Pt) catalyst. Activation was carried out in the same manner as described in Preparation Example 3.

[0256] When injecting the reaction gas, a method was used to inject hydrogen into a container containing liquid trichlorosilane to cause vaporization, and anhydrous hydrogen chloride was added and mixed just before flow into the reactor. Hydrogen was injected at approximately 200 ml / min, and hydrogen chloride was injected at approximately 15 ml / min. The molar ratio of hydrogen chloride to trichlorosilane was approximately 1:2.4.

[0257] The reactor temperature was set to 80°C and the pressure to 1 bar. The results of the gas composition analysis after the reaction under the above-described conditions are presented below in Table 1. Preparation example 12

[0258] The catalytic reactor filled with an ion exchange resin catalyst was prepared and the exhaust gas purification effect was confirmed.

[0259] The catalytic reactor was prepared using a 50 cm long stainless steel tube with an outer diameter of 12.7 mm (1 / 2 inch). 1.3 g of Amberlyst was used as the catalyst in this reactor as an ion exchange resin. ® A-21 (Dow Chemical) was used. Before charging the reactor, the catalyst was impregnated with ethanol, washed with methyl chloride, and then dried and pretreated for 20 hours under nitrogen.

[0260] When injecting the reaction gas, a method was used to inject hydrogen into a container containing liquid trichlorosilane to cause vaporization, and anhydrous hydrogen chloride was added and mixed just before flow into the reactor. Hydrogen was injected at approximately 100 ml / min, and hydrogen chloride was injected at approximately 30 ml / min. The molar ratio of hydrogen chloride to trichlorosilane was approximately 1:1.4.

[0261] The reactor temperature was set to 80°C and the pressure to 1 bar. The results of the gas composition analysis after the reaction under the above-described conditions are presented below in Table 1. Preparation example 13

[0262] The catalytic reactor and activation were prepared in the same manner as described in Preparation Example 12.

[0263] When injecting the reaction gas, a method was used to inject hydrogen into a container containing liquid trichlorosilane to cause vaporization, and anhydrous hydrogen chloride was added and mixed just before flow into the reactor. Hydrogen was injected at approximately 200 ml / min, and hydrogen chloride was injected at approximately 15 ml / min. The molar ratio of hydrogen chloride to trichlorosilane was approximately 1:2.4.

[0264] The reactor temperature was set to 80°C and the pressure to 1 bar. The results of the gas composition analysis after the reaction under the above-described conditions are presented below in Table 1. Preparation example 14

[0265] The catalytic reactor filled with an ion exchange resin catalyst was prepared and the exhaust gas purification effect was confirmed.

[0266] The catalytic reactor was prepared using a stainless steel tube 50 cm long and 12.7 mm (1 / 2 inch) in outer diameter. The ion exchange resin 1.7 g Reillex was used as catalyst in this reactor. ® HP (Vertellus Specialties) was used. Before filling the reactor, the catalyst was soaked with ethanol, washed with methyl chloride, and then dried and pretreated for 20 hours under nitrogen.

[0267] When injecting the reaction gas, a method was used to inject hydrogen into a container containing liquid trichlorosilane to cause vaporization, and anhydrous hydrogen chloride was added and mixed just before flow into the reactor. Hydrogen was injected at approximately 200 ml / min, and hydrogen chloride was injected at approximately 15 ml / min. The molar ratio of hydrogen chloride to trichlorosilane was approximately 1:2.4.

[0268] The reactor temperature was set to 80°C and the pressure to 1 bar. The results of the gas composition analysis after the reaction under the above-described conditions are presented below in Table 1. [Table 1] Preparation example 1 catalyst temperature Molar ratio of the reaction partners TCS / HCl Composition ratio of the discharged gas (unit: mol%) HCl DCS TCS STC HCl acceptance test 1 Amberlyst ® A-21 100°C 20,0 0,1 - 94,7 5,2 98,1 % 2 Amberlyst ® A-21 50°C 50,0 - 2 94 4 100 % 3 Pt(0.5 wt%) / C 150°C 1,4 0,7 - 28,2 71,1 99,0 % 4 AC 150°C 1,4 11,8 0,2 36,9 51,1 81,3 % 5 Pt(0.5 wt%) / C 150°C 1,4 0,6 - 29,0 70,5 99,2 % 6 Pt(0.5 wt%) / C 80°C 1,4 5,1 - 32,2 62,6 92,4 % 7 Pd(0.5 wt%) / C 80°C 1,4 4,3 - 31,6 64,0 93,7 % 8 Pt(0.5 wt%) / C 80°C 2,4 2,4 - 59,3 38,2 94,0 % 9 Pd(0.5 wt%) / C 80°C 2,4 2,2 - 59,3 38,5 94,6 % 10 AC 80°C 2,4 12,6 0,2 63,5 23,7 65,2 % 11 Pd(0.5 wt%) / C 80°C 2,4 0,2 - 58,4 41,4 99,6% 12 Amberlyst ® A-21 80°C 1,4 14,1 0,4 38,5 47,0 76,9 % 13 Amberlyst ® A-21 80°C 2,4 7,2 0,5 61,1 31,2 81,2% 14 Reillex ® HP 80°C 2,4 7,1 0,3 61,1 31,5 81,6 % Examples of the exhaust gas purification process EXAMPLE 1

[0269] The exhaust gas was cleaned with the cleaning device as in Fig. 2 shown cleaned.

[0270] An ion exchange resin catalyst 4 filled catalytic reactor 3 was prepared according to preparation example 1.

[0271] The reactor temperature of the catalytic reactor 3 was set to 100°C and the pressure to 5 bar. The gas fed into the catalytic reactor 3 The exhaust gas flowing consisted of 1 mol% hydrogen chloride, 2 mol% dichlorosilane, 10 mol% trichlorosilane, 7 mol% silicon tetrachloride and 80 mol% hydrogen.

[0272] It was confirmed that the mixed gas 5 , which is produced by the catalytic reactor 3 was composed of 1 mol% dichlorosilane, 11 mol% trichlorosilane, 7 mol% silicon tetrachloride and 81 mol% hydrogen, all of which were removed by the reaction of hydrogen chloride with dichlorosilane under the given conditions and converted to a higher chlorosilane. EXAMPLE 2

[0273] The exhaust gas was cleaned with the cleaning device as in Fig. 3 shown cleaned.

[0274] An ion exchange resin catalyst 140 filled catalytic reactor 130 was prepared according to preparation example 1.

[0275] The reactor temperature of the catalytic reactor 130 was set to 100°C and the pressure to 5 bar. The gas fed into the catalytic reactor 130 flowing exhaust gas consisted of 1 mol% hydrogen chloride, 2 mol% dichlorosilane, 10 mol% trichlorosilane, 7 mol% silicon tetrachloride, 7 mol% silicon tetrachloride and 80 mol% hydrogen.

[0276] The catalytic reactor 130 conducted mixed gas 150 consisted of 1 mol% dichlorosilane, 11 mol% trichlorosilane, 7 mol% silicon tetrachloride and 81 mol% hydrogen.

[0277] In the first distillation column 160 A cleaning temperature distribution of –5 to –60°C and the pressure was set to 23 bar.

[0278] As a result, the above from the first distillation column 160 Ejected streams of 0.01 mol% dichlorosilane, 0.03 mol% trichlorosilane, 0.001 mol% silicon tetrachloride and 99.96 mol% hydrogen were detected and it was confirmed that streams consisting of high purity hydrogen were emitted. EXAMPLE 3

[0279] The exhaust gas was cleaned with the cleaning device as in Fig. 4 shown cleaned.

[0280] An ion exchange resin catalyst 204 filled catalytic reactor 203 was prepared according to preparation example 1.

[0281] The reactor temperature of the catalytic reactor 203 was set to 100°C and the pressure to 5 bar. The gas fed into the catalytic reactor 203 The exhaust gas flowing consisted of 1 mol% hydrogen chloride, 2 mol% dichlorosilane, 10 mol% trichlorosilane, 7 mol% silicon tetrachloride and 80 mol% hydrogen.

[0282] The mixed gas 219 , which is produced by the catalytic reactor 203 and then into the separation membrane 220 flowed consisted of 1 mol% dichlorosilane, 11 mol% trichlorosilane, 7 mol% silicon tetrachloride and 81 mol% hydrogen.

[0283] The temperature in the separator 216 was set to –5°C and the pressure to 3 bar.

[0284] As a result, the separation membrane 220 The ejected stream consisted of 0.01 mol% dichlorosilane, 0.03 mol% trichlorosilane, 0.001 mol% silicon tetrachloride, and 99.96 mol% hydrogen, and it was confirmed that streams consisting of high-purity hydrogen were ejected. EXAMPLE 4

[0285] The exhaust gas was cleaned with the cleaning device as in Fig. 5 shown cleaned.

[0286] An ion exchange resin catalyst 555 filled catalytic reactor 550 was prepared according to preparation example 2.

[0287] The temperature in the separator 515 was set to –5°C and the pressure to 3 bar. The temperature of the catalytic reactor 550 was set to 50°C and the pressure to 11 bar.

[0288] The flow of the condensed phase passing through the separator 515 and then into the reactor 550 flowed consisted of 2 mol% hydrogen chloride, 9 mol% dichlorosilane, 54 mol% trichlorosilane, 34 mol% silicon tetrachloride and 1 mol% hydrogen.

[0289] As a result, the reactor 550 The ejected stream consisted of 2 mol% dichlorosilane, 67 mol% trichlorosilane, 29 mol% silicon tetrachloride, and 2 mol% hydrogen, and it was confirmed that streams were ejected in a state with all hydrogen chloride removed. EXAMPLE 5

[0290] The exhaust gas was cleaned with the cleaning device as in Fig. 6 shown cleaned.

[0291] An ion exchange resin catalyst 655 filled catalytic reactor 250 was prepared according to preparation example 2.

[0292] The temperature in the separator 615 was set to –5°C and the pressure to 3 bar. The reactor temperature of the catalytic reactor 650 was set to 50°C and the pressure to 11 bar. The flow of the non-condensed phase emerging from the top of the separator 615 flowed into a second cooler 620 and was then cooled again by low-temperature cooling. The condensed stream was returned to the separator 615 The cooling condition for low-temperature cooling in a second cooler 620 was set to –40°C and the pressure to 23 bar.

[0293] The flow of the non-condensed phase passing through the separator 615 and the second cooler 620 and then into the absorption column 625 showed that 66 mol% hydrogen chloride, 88 mol% dichlorosilane, 99 mol% trichlorosilane, 97 mol% silicon tetrachloride were reduced compared to not using a second cooler 620 It was confirmed that the current flowing from the bottom of the catalytic reactor 250 and into the absorption column 625 was reduced by 56% and an energy saving of about 10.3% was realized.

[0294] The flow of the condensed phase passing through the separator 615 and then into the reactor 650 flowed consisted of 2 mol% hydrogen chloride, 9 mol% dichlorosilane, 54 mol% trichlorosilane, 34 mol% silicon tetrachloride and 1 mol% hydrogen.

[0295] As a result, the reactor 650 The ejected stream consisted of 2 mol% dichlorosilane, 67 mol% trichlorosilane, 29 mol% silicon tetrachloride, and 2 mol% hydrogen, and it was confirmed that streams were ejected in a state with all hydrogen chloride removed. EXAMPLE 6

[0296] The exhaust gas was treated according to the process flow diagram in Fig. 7 cleaned.

[0297] The temperature in the separator used in the first condensation and separation step was set to -5°C and the pressure to 3.4 bar. The temperature of the catalytic reactor used in the catalytic reaction step was set to 100°C and the pressure to 23.85 bar. This time, the catalytic reactor was prepared according to Preparation Example 1.

[0298] The non-condensed phase stream, which passed through the separator and then flowed into the catalytic reactor, consisted of 1.1 mol% hydrogen chloride, 1.1 mol% dichlorosilane, 2.9 mol% trichlorosilane, 0.7 mol% silicon tetrachloride, and 94.2 mol% hydrogen. The stream exiting the catalytic reactor consisted of 0.2 mol% dichlorosilane, 3.6 mol% trichlorosilane, 0.9 mol% silicon tetrachloride, and 95.3 mol% hydrogen, and it was confirmed that streams were discharged in a state with all hydrogen chloride removed.

[0299] The streams with reduced hydrogen chloride content were condensed in the second condensation and separation step at -35°C. This time, the non-condensed phase consisted of 0.2 mol% trichlorosilane and 99.8 mol% hydrogen, and it was confirmed that high-purity hydrogen could be recovered via a bottom adsorption column.

[0300] In addition, the condensed phase stream separated by the second condensation and separation step was combined with the condensed phase stream separated by the first condensation and separation step and injected into the distillation step to separate the silane-based compound. This time, the combined streams injected into the distillation step consisted of 0.2 mol% hydrogen chloride, 6.1 mol% dichlorosilane, 58.7 mol% trichlorosilane, and 35.0 mol% silicon tetrachloride.

[0301] By carrying out the exhaust gas purification as described above, it was confirmed that an energy consumption saving of about 40% was achieved compared to conventional processes. EXAMPLE 7

[0302] The exhaust gas was measured according to the Fig. 9 shown process flow diagram.

[0303] The temperature in the separator used in the first condensation and separation step was set to -5°C and the pressure was set to 3.4 bar. The reaction temperature of the catalytic reactor used in the catalytic reaction step was set to 100°C and the pressure was set to 23.85 bar. At this time, the catalytic reactor was prepared according to Preparation Example 1.

[0304] The composition of the non-condensed phase stream that passed through the separator and then flowed into the catalytic reactor was 1.1 mol% hydrogen chloride, 1.1 mol% dichlorosilane, 2.9 mol% trichlorosilane, 0.7 mol% silicon tetrachloride, and 94.2 mol% hydrogen. The composition of the streams discharged from the catalytic reactor was 0.2 mol% dichlorosilane, 3.6 mol% trichlorosilane, 0.9 mol% silicon tetrachloride, and 95.3 mol% hydrogen, and it was confirmed that the streams were discharged in a state where all hydrogen chloride had been eliminated.

[0305] The streams with reduced concentration of hydrogen chloride were condensed to -35°C in the second condensation and separation step. At this time, the composition of the uncondensed phase was 0.2 mol% trichlorosilane and 99.8 mol% hydrogen, and high-purity hydrogen could be recovered by a subsequent adsorption step.

[0306] Furthermore, the condensed phase stream separated from the second condensation and separation step was combined with the condensed phase stream separated from the first condensation and separation step and injected into the first distillation step to separate hydrogen chloride. At this time, the composition of the combined stream injected into the distillation step was 0.2 mol% hydrogen chloride, 6.1 mol% dichlorosilane, 58.7 mol% trichlorosilane, and 35.0 mol% silicon tetrachloride. The temperature in the distillation column used in the first distillation step was adjusted to a range of -35 to 150°C, and the pressure was set to 12.3 bar. The streams of the chlorosilane-based compound separated in the first distillation step were injected into the second distillation step to separate the silane-based compound.

[0307] When carrying out the exhaust gas purification described above, it was confirmed that the effects of reducing energy consumption by around 38% were realized compared to the conventional process. EXAMPLE 8

[0308] The exhaust gas was measured according to the Fig. 12 shown process flow diagram.

[0309] The temperature in the separator used in the first condensation and separation step was set to -5°C and the pressure was set to 3.4 bar. The reaction temperature of the first catalytic reactor used in the first catalytic reaction step was set to 100°C and the pressure was set to 23.85 bar. At this time, the first catalytic reactor was prepared according to Preparation Example 1.

[0310] The composition of the non-condensed phase stream that passed through the separator and then flowed into the catalytic reactor was 1.1 mol% hydrogen chloride, 1.1 mol% dichlorosilane, 2.9 mol% trichlorosilane, 0.7 mol% silicon tetrachloride, and 94.2 mol% hydrogen. The composition of the stream discharged from the catalytic reactor was 0.2 mol% dichlorosilane, 3.6 mol% trichlorosilane, 0.9 mol% silicon tetrachloride, and 95.3 mol% hydrogen, and it was confirmed that the streams were discharged in a state where all hydrogen chloride had been eliminated.

[0311] The streams with reduced concentration of hydrogen chloride were condensed to -35°C in the second condensation and separation step. At this time, the composition of the uncondensed phase was 0.2 mol% trichlorosilane and 99.8 mol% hydrogen, and high-purity hydrogen could be recovered by a subsequent adsorption step.

[0312] Furthermore, the mixture of the condensed phase stream separated from the second condensation and separation step was combined with the condensed phase stream derived from the first condensation and separation step and injected into the second catalytic reactor to perform the second catalytic reaction step for hydrogen chloride elimination. At this time, the composition of the streams fed into the second catalytic reactor was 0.2 mol% hydrogen chloride, 6.1 mol% dichlorosilane, 58.7 mol% trichlorosilane, and 35.0 mol% silicon tetrachloride.

[0313] The reaction temperature in the second catalytic reactor was set to 50°C and the pressure was set to 12.3 bar. The second catalytic reactor was prepared according to Preparation Example 2.

[0314] The composition of the streams discharged from the second catalytic reactor was 5.7 mol% dichlorosilane, 58.3 mol% trichlorosilane, and 36.0 mol% silicon tetrachloride, and it was confirmed that the streams were discharged in a state where all hydrogen chloride had been eliminated. The stream of the chlorosilane-based compound discharged from the second catalytic reactor was injected into the distillation step to separate the silane-based compound.

[0315] When carrying out the exhaust gas purification described above, it was confirmed that the effects of reducing energy consumption by around 40% compared to the conventional process were realized. EXAMPLE 9

[0316] The exhaust gas was measured according to the Fig. 7 shown process flow diagram.

[0317] The temperature in the separator used in the first condensation and separation step was set to -5°C and the pressure was set to 3.4 bar. The reaction temperature of the catalytic reactor used in the catalytic reaction step was set to 150°C and the pressure was set to 23.85 bar. At this time, the first catalytic reactor was prepared according to Preparation Example 3.

[0318] The composition of the non-condensed phase stream that passed through the separator and then flowed into the catalytic reactor was 1.1 mol% hydrogen chloride, 1.1 mol% dichlorosilane, 2.9 mol% trichlorosilane, 0.7 mol% silicon tetrachloride, and 94.2 mol% hydrogen. The composition of the stream discharged from the catalytic reactor was 0.2 mol% dichlorosilane, 3.6 mol% trichlorosilane, 0.9 mol% silicon tetrachloride, and 95.3 mol% hydrogen, and it was confirmed that the streams were discharged in a state where all hydrogen chloride had been eliminated.

[0319] The stream with reduced concentration of hydrogen chloride was condensed to -35°C in the second condensation and separation step. At this time, the composition of the uncondensed phase was 0.2 mol% trichlorosilane and 99.8 mol% hydrogen, and high-purity hydrogen could be recovered by a subsequent adsorption column.

[0320] Furthermore, the condensed phase stream separated from the second condensation and separation step was combined with the condensed phase stream separated from the first condensation and separation step and injected into the distillation step to separate a silane-based compound. At this time, the composition of the stream fed into the distillation step was 0.2 mol% hydrogen chloride, 6.1 mol% dichlorosilane, 58.7 mol% trichlorosilane, and 35.0 mol% silicon tetrachloride.

[0321] When carrying out the exhaust gas purification described above, it was confirmed that the effects of reducing energy consumption by around 30% compared to the conventional process were realized. EXAMPLE 10

[0322] The exhaust gas was measured according to the Fig. 8 shown process flow diagram.

[0323] The temperature in the separator used in the first condensation and separation step was set to -5°C and the pressure was set to 3.4 bar. The reaction temperature of the catalytic reactor used in the catalytic reaction step was set to 100°C and the pressure was set to 23.85 bar. At this time, the catalytic reactor was prepared according to Preparation Example 1.

[0324] The composition of the non-condensed phase stream that passed through the separator and then flowed into the catalytic reactor was 1.1 mol% hydrogen chloride, 1.1 mol% dichlorosilane, 2.9 mol% trichlorosilane, 0.7 mol% silicon tetrachloride, and 94.2 mol% hydrogen. The composition of the stream discharged from the catalytic reactor was 0.2 mol% dichlorosilane, 3.6 mol% trichlorosilane, 0.9 mol% silicon tetrachloride, and 95.3 mol% hydrogen, and it was confirmed that the streams were discharged in a state where all hydrogen chloride had been eliminated.

[0325] The stream with a reduced concentration of hydrogen chloride was condensed to -35°C in the second condensation and separation step. At this point, the composition of the uncondensed phase was 0.2 mol% trichlorosilane and 99.8 mol% hydrogen, and high-purity hydrogen could be recovered through a subsequent adsorption column. The chlorosilane-based stream separated from the second condensation and separation step contained 3.2 mol% dichlorosilane, 76.4 mol% trichlorosilane, and 20.4 mol% silicon tetrachloride, and these streams were recycled to the separator in the first condensation and separation step.

[0326] On the other hand, the condensed phase stream separated from the first condensation and separation step was injected into the distillation step for the separation of a silane-based compound.

[0327] When carrying out the exhaust gas purification described above, it was confirmed that the effects of reducing energy consumption by around 35% were realized compared to the conventional process. Example 11

[0328] The exhaust gas was measured according to the Fig. 9 shown process flow diagram.

[0329] The temperature in the separator used in the first condensation and separation step was set to -5°C and the pressure was set to 3.4 bar. The reaction temperature of the catalytic reactor used in the catalytic reaction step was set to 150°C and the pressure was set to 12.0 bar. The catalytic reactor was prepared according to Preparation Example 3.

[0330] The composition of the non-condensed phase stream that passed through the separator and then flowed into the catalytic reactor was 1.1 mol% hydrogen chloride, 1.1 mol% dichlorosilane, 2.9 mol% trichlorosilane, 0.7 mol% silicon tetrachloride, and 94.2 mol% hydrogen. The composition of the stream discharged from the catalytic reactor was 0.2 mol% dichlorosilane, 3.6 mol% trichlorosilane, 0.9 mol% silicon tetrachloride, and 95.3 mol% hydrogen, and it was confirmed that the streams were discharged in a state where all hydrogen chloride had been eliminated.

[0331] The stream with reduced concentration of hydrogen chloride was condensed to -35°C in the second condensation and separation step. At this time, the composition of the uncondensed phase was 0.2 mol% trichlorosilane and 99.8 mol% hydrogen, and high-purity hydrogen could be recovered by a subsequent adsorption step.

[0332] Furthermore, the condensed phase stream separated from the second condensation and separation step was combined with the condensed phase stream separated from the first condensation and separation step and injected into the first distillation step to separate hydrogen chloride. At this time, the composition of the stream fed into the first distillation step was 0.2 mol% hydrogen chloride, 6.1 mol% dichlorosilane, 58.7 mol% trichlorosilane, and 35.0 mol% silicon tetrachloride.

[0333] The temperature in the distillation column used in the first distillation step was adjusted to a range of -35 to 150°C, and the pressure was set to 12.3 bar. The stream of the chlorosilane-based compound separated in the first distillation step was injected into the second distillation step to separate the silane-based compound.

[0334] When carrying out the exhaust gas purification described above, it was confirmed that the effects of reducing energy consumption by about 45% were realized compared to the conventional process. EXAMPLE 12

[0335] The exhaust gas was measured according to the Fig. 10 shown process flow diagram.

[0336] The temperature in the separator used in the first condensation and separation step was set to -5°C and the pressure was set to 3.4 bar. The reaction temperature of the catalytic reactor used in the catalytic reaction step was set to 100°C and the pressure was set to 12.0 bar. The catalytic reactor was prepared according to Preparation Example 1.

[0337] The composition of the non-condensed phase stream that passed through the separator and then flowed into the catalytic reactor was 1.1 mol% hydrogen chloride, 1.1 mol% dichlorosilane, 2.9 mol% trichlorosilane, 0.7 mol% silicon tetrachloride, and 94.2 mol% hydrogen. The composition of the stream discharged from the catalytic reactor was 0.2 mol% dichlorosilane, 3.6 mol% trichlorosilane, 0.9 mol% silicon tetrachloride, and 95.3 mol% hydrogen, and it was confirmed that the streams were discharged in a state where all hydrogen chloride had been eliminated.

[0338] The stream with reduced concentration of hydrogen chloride was condensed to -35°C in the second condensation and separation step. At this time, the composition of the uncondensed phase was 0.2 mol% trichlorosilane and 99.8 mol% hydrogen, and high-purity hydrogen could be recovered by a subsequent adsorption step.

[0339] Furthermore, the condensed phase stream separated from the second condensation and separation step was combined with the chlorosilane-based compound stream separated from the first condensation and separation step below and then transferred to the second distillation step for separation of the chlorosilane-based compound. At this time, the composition of the stream fed to the second distillation step was 5.7 mol% dichlorosilane, 58.3 mol% trichlorosilane, and 36.0 mol% silicon tetrachloride.

[0340] On the other hand, the condensed phase stream separated from the first condensation and separation step was transferred to the first distillation step. The temperature in the distillation column used in the first distillation step was adjusted to a range of -35 to 150°C, and the pressure was set to 12.3 bar. The stream of the chlorosilane-based compound separated in the first distillation step was injected into the second distillation step to separate the silane-based compound.

[0341] When carrying out the exhaust gas purification described above, it was confirmed that the effects of reducing energy consumption by about 50% compared to the conventional process were realized. EXAMPLE 13

[0342] The exhaust gas was measured according to the Fig. 11 shown process flow diagram.

[0343] The temperature in the separator used in the first condensation and separation step was set to -5°C and the pressure was set to 3.4 bar. The reaction temperature of the catalytic reactor used in the catalytic reaction step was set to 80°C and the pressure was set to 12.0 bar. The catalytic reactor was prepared according to Preparation Example 1.

[0344] The composition of the non-condensed phase stream that passed through the separator and then flowed into the catalytic reactor was 1.1 mol% hydrogen chloride, 1.1 mol% dichlorosilane, 2.9 mol% trichlorosilane, 0.7 mol% silicon tetrachloride, and 94.2 mol% hydrogen. The composition of the stream discharged from the catalytic reactor was 0.2 mol% dichlorosilane, 3.6 mol% trichlorosilane, 0.9 mol% silicon tetrachloride, and 95.3 mol% hydrogen, and it was confirmed that the streams were discharged in a state where all hydrogen chloride had been eliminated.

[0345] The stream with reduced concentration of hydrogen chloride was condensed to -35°C in the second condensation and separation step. At this time, the composition of the uncondensed phase was 0.2 mol% trichlorosilane and 99.8 mol% hydrogen, and high-purity hydrogen could be recovered by a subsequent adsorption step.

[0346] At this point, the composition of the condensed phase was 3.2 mol% dichlorosilane, 76.4 mol% trichlorosilane, and 20.4 mol% silicon tetrachloride. These streams were recycled to the separator of the first condensation and separation step.

[0347] On the other hand, the condensed phase stream separated from the first condensation and separation step was transferred to the first distillation step. The temperature in the distillation column used in the first distillation step was adjusted to a range of -35 to 150°C, and the pressure was set to 12.3 bar. The stream of the chlorosilane-based compound separated in the first distillation step was injected into the second distillation step to separate the silane-based compound.

[0348] When carrying out the exhaust gas purification described above, it was confirmed that the effects of reducing energy consumption by about 53% were realized compared to the conventional process. EXAMPLE 14

[0349] The exhaust gas was measured according to the Fig. 12 shown process flow diagram.

[0350] The temperature in the separator used in the first condensation and separation step was set to -5°C and the pressure was set to 3.4 bar. The reaction temperature of the catalytic reactor used in the catalytic reaction step was set to 150°C and the pressure was set to 12.0 bar. The catalytic reactor was prepared according to Preparation Example 3.

[0351] The composition of the non-condensed phase stream that passed through the separator and then flowed into the catalytic reactor was 1.1 mol% hydrogen chloride, 1.1 mol% dichlorosilane, 2.9 mol% trichlorosilane, 0.7 mol% silicon tetrachloride, and 94.2 mol% hydrogen. The composition of the stream discharged from the catalytic reactor was 0.2 mol% dichlorosilane, 3.6 mol% trichlorosilane, 0.9 mol% silicon tetrachloride, and 95.3 mol% hydrogen, and it was confirmed that the streams were discharged in a state where all hydrogen chloride had been eliminated.

[0352] The stream with reduced concentration of hydrogen chloride was condensed to -35°C in the second condensation and separation step. At this time, the composition of the uncondensed phase was 0.2 mol% trichlorosilane and 99.8 mol% hydrogen, and high-purity hydrogen could be recovered by a subsequent adsorption step.

[0353] Furthermore, the condensed phase stream separated from the second condensation and separation step was combined with the condensed phase stream derived from the first condensation and separation step and injected into the second catalytic reactor to perform the second catalytic reaction step for hydrogen chloride elimination. At this time, the composition of the stream fed into the second catalytic reactor was 0.2 mol% hydrogen chloride, 6.1 mol% dichlorosilane, 58.7 mol% trichlorosilane, and 35.0 mol% silicon tetrachloride.

[0354] The reaction temperature in the second catalytic reactor was set to 50°C and the pressure was set to 12.3 bar. The catalytic reactor was prepared according to Preparation Example 2.

[0355] The composition of the stream discharged from the second catalytic reactor was 5.7 mol% dichlorosilane, 58.3 mol% trichlorosilane, and 36.0 mol% silicon tetrachloride, and it was confirmed that the streams discharged were in a state where all hydrogen chloride had been eliminated. The stream of the chlorosilane-based compound separated in the second distillation step was injected into the distillation step to separate the silane-based compound.

[0356] When carrying out the exhaust gas purification described above, it was confirmed that the effects of reducing energy consumption by around 47% were realized compared to the conventional process. EXAMPLE 15

[0357] The exhaust gas was measured according to the Fig. 13 shown process flow diagram.

[0358] The temperature in the separator used in the first condensation and separation step was set to -5°C and the pressure was set to 3.4 bar. The reaction temperature of the first catalytic reactor used in the first catalytic reaction step was set to 100°C and the pressure was set to 12.0 bar. The first catalytic reactor was prepared according to Preparation Example 1.

[0359] The composition of the non-condensed phase stream that passed through the separator and then flowed into the first catalytic reactor was 1.1 mol% hydrogen chloride, 1.1 mol% dichlorosilane, 2.9 mol% trichlorosilane, 0.7 mol% silicon tetrachloride, and 94.2 mol% hydrogen. The composition of the stream discharged from the catalytic reactor was 0.2 mol% dichlorosilane, 3.6 mol% trichlorosilane, 0.9 mol% silicon tetrachloride, and 95.3 mol% hydrogen, and it was confirmed that the streams were discharged in a state where all hydrogen chloride had been eliminated.

[0360] The stream with reduced concentration of hydrogen chloride was condensed to -35°C in the second condensation and separation step. At this time, the composition of the uncondensed phase was 0.2 mol% trichlorosilane and 99.8 mol% hydrogen, and high-purity hydrogen could be recovered by a subsequent adsorption step.

[0361] Furthermore, the condensed phase stream separated from the second condensation and separation step was combined with the condensed phase stream derived from the first condensation and separation step and transferred to the distillation step for the separation of a silane-based compound.

[0362] On the other hand, the condensed phase stream separated from the first condensation and separation step was injected into the second catalytic reactor to perform the second catalytic reaction step for hydrogen chloride elimination. At this time, the composition of the stream fed into the second catalytic reactor was 0.2 mol% hydrogen chloride, 6.1 mol% dichlorosilane, 56.9 mol% trichlorosilane, and 33.1 mol% silicon tetrachloride.

[0363] The reaction temperature in the second catalytic reactor was set to 50°C and the pressure was set to 12.3 bar. The catalytic reactor was prepared according to Preparation Example 2.

[0364] The composition of the stream discharged from the second catalytic reactor was 5.7 mol% dichlorosilane, 58.3 mol% trichlorosilane, and 36.0 mol% silicon tetrachloride, and it was confirmed that the streams discharged were in a state where all hydrogen chloride had been eliminated. The stream of the chlorosilane-based compound separated in the second distillation step was injected into the distillation step to separate the silane-based compound.

[0365] When carrying out the exhaust gas purification described above, it was confirmed that the effects of reducing energy consumption by around 52% compared to the conventional process were realized. EXAMPLE 16

[0366] The exhaust gas was measured according to the Fig. 14 shown process flow diagram.

[0367] The temperature in the separator used in the first condensation and separation step was set to -5°C and the pressure was set to 3.4 bar. The reaction temperature of the first catalytic reactor used in the first catalytic reaction step was set to 80°C and the pressure was set to 12.0 bar. The first catalytic reactor was prepared according to Preparation Example 1.

[0368] The composition of the non-condensed phase stream that passed through the separator and then flowed into the first catalytic reactor was 1.1 mol% hydrogen chloride, 1.1 mol% dichlorosilane, 2.9 mol% trichlorosilane, 0.7 mol% silicon tetrachloride, and 94.2 mol% hydrogen. The composition of the stream discharged from the catalytic reactor was 0.2 mol% dichlorosilane, 3.6 mol% trichlorosilane, 0.9 mol% silicon tetrachloride, and 95.3 mol% hydrogen, and it was confirmed that the streams were discharged in a state where all hydrogen chloride had been eliminated.

[0369] The stream with reduced concentration of hydrogen chloride was condensed to -35°C in the second condensation and separation step. At this time, the composition of the uncondensed phase was 0.2 mol% trichlorosilane and 99.8 mol% hydrogen, and high-purity hydrogen could be recovered by a subsequent adsorption step.

[0370] In addition, the composition of the condensed phase was 3.2 mol% dichlorosilane, 76.4 mol% trichlorosilane, and 20.4 mol% silicon tetrachloride, and this stream was recycled to the separator used in the first condensation and separation step.

[0371] On the other hand, the condensed phase stream derived from the first condensation and separation step was injected into the second catalytic reactor to perform the second catalytic reaction step for hydrogen chloride elimination. At this time, the composition of the stream fed into the second catalytic reactor was 0.2 mol% hydrogen chloride, 6.1 mol% dichlorosilane, 56.9 mol% trichlorosilane, and 33.1 mol% silicon tetrachloride.

[0372] The reaction temperature in the second catalytic reactor was set to 50°C and the pressure was set to 12.3 bar. The catalytic reactor was prepared according to Preparation Example 2.

[0373] The composition of the stream discharged from the second catalytic reactor was 5.7 mol% dichlorosilane, 58.3 mol% trichlorosilane, and 36.0 mol% silicon tetrachloride, and it was confirmed that the streams discharged were in a state where all hydrogen chloride had been eliminated. The stream of the chlorosilane-based compound separated in the second distillation step was injected into the distillation step to separate the silane-based compound.

[0374] When carrying out the exhaust gas purification described above, it was confirmed that the effects of reducing energy consumption by around 55% were realized compared to the conventional process. List of reference symbols 10, 100, 200, 300 exhaust gas cleaning device 3, 130, 203, 550, 650 catalytic reactor 6, 229 Distillation column 160, 345 First distillation column 190, 360 Second distillation column 216, 315, 515, 615 separators S10, S110, S210 First condensation and separation step S20, S120, S220 compaction step S30, S130 step of the catalytic reaction S40, S140, S240 Second condensation and separation step S50, S150, S250 adsorption step S60, S270 Distillation step S160 First distillation step S170 Second distillation step S230 First step of the catalytic reaction S260 Second step of the catalytic reaction< / beispiel>

Claims

[1] Exhaust gas purification process comprising the following steps: Passing the exhaust gas discharged after performing a polysilicon deposition process by a chemical vapor deposition (CVD) reaction through a catalytic reactor containing an ion exchange resin catalyst for reducing the concentration of hydrogen chloride; and Passing the exhaust gas through the catalytic reactor and then separating hydrogen and chlorosilane-based compounds contained in the passed exhaust gas. [2] The exhaust gas purification method according to claim 1, wherein the ion exchange resin catalyst contains a cyclic amine compound, a styrene-based polymer having an amine group, a styrene-divinylbenzene-based polymer having an amine group, an acrylic polymer having an amine group, or mixtures thereof. [3] The exhaust gas purification method according to claim 1, wherein the exhaust gas is hydrogen chloride (HCl), hydrogen (H2 ) and chlorosilane-based compounds. [4] The exhaust gas purification method according to claim 1, wherein the content of hydrogen chloride contained in the exhaust gas passed through the catalytic reactor is reduced to about 80 mol% or more with respect to the content before passing through the catalytic reactor. [5] The exhaust gas purification method according to claim 1, wherein the exhaust gas is converted into trichlorosilane and silicon tetrachloride by passing it through the catalytic reactor. [6] Exhaust gas purification device comprising: a catalytic reactor containing an ion exchange resin catalyst and reducing the concentration of hydrogen chloride by passing the exhaust gas discharged after performing a polysilicon deposition process by a chemical vapor deposition (CVD) reaction; and a separation device that separates hydrogen and a chlorosilane-based compound from the exhaust gas passed through the catalytic reactor. [7] The exhaust gas purification device according to claim 6, wherein the ion exchange resin catalyst contains a cyclic amine compound, a styrene-based polymer having an amine group, a styrene-divinylbenzene-based polymer having an amine group, an acrylic polymer having an amine group, or mixtures thereof. [8] An exhaust gas purification device according to claim 6, wherein the separation device includes one or more elements selected from the group consisting of a separator, a distillation device, a separation membrane device, and a gas-liquid separation device. [9] Exhaust gas purification process comprising the following steps: Separating the exhaust gas discharged after performing a polysilicon deposition process by a chemical vapor deposition (CVD) reaction into a non-condensed phase stream and a condensed phase stream; and Passing the condensed phase stream through a catalytic reactor including an ion exchange resin catalyst to reduce the concentration of hydrogen chloride. [10] The exhaust gas purification method according to claim 9, wherein the ion exchange resin catalyst contains a cyclic amine compound, a styrene-based polymer having an amine group, a styrene-divinylbenzene-based polymer having an amine group, an acrylic polymer having an amine group, or mixtures thereof. [11] The exhaust gas purification method according to claim 9, wherein the exhaust gas is hydrogen chloride (HCl), hydrogen (H 2 ) and chlorosilane-based compounds. [12] The exhaust gas purification method according to claim 9, wherein the content of hydrogen chloride contained in the condensed phase stream passed through the catalytic reactor is reduced to about 80 mol% or more with respect to the content before passing through the catalytic reactor. [13] The exhaust gas purification method according to claim 9, wherein the condensed phase stream is converted into trichlorosilane and silicon tetrachloride by passing it through the catalytic reactor. [14] The exhaust gas purification method according to claim 9, wherein, after passing the condensed phase stream through the catalytic reactor, a step of separating the chlorosilane-based compound contained in the passed condensed phase stream is further included. [15] Exhaust gas purification device comprising: a separation device that separates the exhaust gas discharged after performing a polysilicon deposition process by a chemical vapor deposition (CVD) reaction into a non-condensed phase stream and a condensed phase stream; and a catalytic reactor containing an ion exchange resin catalyst that reduces the concentration of hydrogen chloride from the condensed phase stream. [16] The exhaust gas purification device according to claim 15, wherein the ion exchange resin catalyst contains a cyclic amine compound, a styrene-based polymer having an amine group, a styrene-divinylbenzene-based polymer having an amine group, an acrylic polymer having an amine group, or mixtures thereof. [17] The exhaust gas purification device according to claim 15, wherein the separation device includes one or more members selected from the group consisting of a separator, a distillation device, a separation membrane device, a gas-liquid separation device, an absorption column, and an adsorption column. [18] An exhaust gas purification device according to claim 15, further comprising a first cooler disposed at the front end of the separator and cooling the exhaust gas. [19] Exhaust gas purification process comprising the following steps: Separating the exhaust gas discharged after performing a polysilicon deposition process by a chemical vapor deposition (CVD) reaction into a non-condensed phase stream and a condensed phase stream; Passing the uncondensed phase stream through a first catalytic reactor to reduce the concentration of hydrogen chloride; and Separating the chlorosilane-based compound of the condensed phase stream according to the boiling point. [20] The exhaust gas purification method according to claim 19, wherein the catalyst used in the first catalytic reactor includes one or more elements selected from the group consisting of an ion exchange resin and a transition metal. [21] The exhaust gas purification device according to claim 20, wherein the ion exchange resin catalyst contains a cyclic amine compound, a styrene-based polymer having an amine group, a styrene-divinylbenzene-based polymer having an amine group, an acrylic polymer having an amine group, or mixtures thereof. [22] The exhaust gas purification method according to claim 19, wherein the exhaust gas is hydrogen chloride (HCl), hydrogen (H 2) and chlorosilane-based compounds. [23] The exhaust gas purification method according to claim 19, wherein the exhaust gas is condensed at more than -30°C and less than 10°C to separate it into the non-condensed phase stream and the condensed phase stream. [24] The exhaust gas purification method according to claim 19, wherein the content of hydrogen chloride contained in the non-condensed phase stream passed through the catalytic reactor is reduced to about 80 mol% or more with respect to the content before passing through the catalytic reactor. [25] The exhaust gas purification method according to claim 19, wherein the non-condensed phase stream is converted into trichlorosilane and silicon tetrachloride by passing it through the catalytic reactor. [26] The exhaust gas purification method according to claim 19, further comprising a step of separating the non-condensed phase stream passed through the first catalytic reactor into a hydrogen stream and a chlorosilane-based stream. [27] The exhaust gas purification method according to claim 26, wherein the separated chlorosilane-based stream is combined with the condensed phase stream and passed to a step of separating the chlorosilane-based compound of the condensed phase stream according to the boiling point. [28] The purification method for exhaust gas according to claim 19, wherein, before performing a step of separating the chlorosilane-based compound of the condensed phase stream according to the boiling point, a step of lowering the concentration of hydrogen chloride contained in the condensed phase stream is further included. [29] The exhaust gas purification method according to claim 28, wherein the step of lowering the concentration of hydrogen chloride contained in the condensed phase stream is carried out by distilling the condensed phase stream or by introducing it through the second catalytic reactor. [30] The exhaust gas purification method according to claim 29, wherein the catalyst used in the first catalytic reactor includes one or more elements selected from the group consisting of an ion exchange resin and a transition metal.