Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J19/02—Apparatus characterised by being constructed of material selected for its chemically-resistant properties
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B33/00—Silicon; Compounds thereof
  • C01B33/08—Compounds containing halogen
  • C01B33/107—Halogenated silanes
  • C01B33/1071—Tetrachloride, trichlorosilane or silicochloroform, dichlorosilane, monochlorosilane or mixtures thereof
  • C01B33/10742—Tetrachloride, trichlorosilane or silicochloroform, dichlorosilane, monochlorosilane or mixtures thereof prepared by hydrochlorination of silicon or of a silicon-containing material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
  • B01J8/02—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds
  • B01J8/06—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds in tube reactors; the solid particles being arranged in tubes
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B33/00—Silicon; Compounds thereof
  • C01B33/02—Silicon
  • C01B33/021—Preparation
  • C01B33/027—Preparation by decomposition or reduction of gaseous or vaporised silicon compounds other than silica or silica-containing material
  • C01B33/029—Preparation by decomposition or reduction of gaseous or vaporised silicon compounds other than silica or silica-containing material by decomposition of monosilane
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B33/00—Silicon; Compounds thereof
  • C01B33/02—Silicon
  • C01B33/021—Preparation
  • C01B33/027—Preparation by decomposition or reduction of gaseous or vaporised silicon compounds other than silica or silica-containing material
  • C01B33/035—Preparation by decomposition or reduction of gaseous or vaporised silicon compounds other than silica or silica-containing material by decomposition or reduction of gaseous or vaporised silicon compounds in the presence of heated filaments of silicon, carbon or a refractory metal, e.g. tantalum or tungsten, or in the presence of heated silicon rods on which the formed silicon is deposited, a silicon rod being obtained, e.g. Siemens process
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B33/00—Silicon; Compounds thereof
  • C01B33/08—Compounds containing halogen
  • C01B33/107—Halogenated silanes
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B33/00—Silicon; Compounds thereof
  • C01B33/08—Compounds containing halogen
  • C01B33/107—Halogenated silanes
  • C01B33/1071—Tetrachloride, trichlorosilane or silicochloroform, dichlorosilane, monochlorosilane or mixtures thereof
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B33/00—Silicon; Compounds thereof
  • C01B33/08—Compounds containing halogen
  • C01B33/107—Halogenated silanes
  • C01B33/1071—Tetrachloride, trichlorosilane or silicochloroform, dichlorosilane, monochlorosilane or mixtures thereof
  • C01B33/10742—Tetrachloride, trichlorosilane or silicochloroform, dichlorosilane, monochlorosilane or mixtures thereof prepared by hydrochlorination of silicon or of a silicon-containing material
  • C01B33/10757—Tetrachloride, trichlorosilane or silicochloroform, dichlorosilane, monochlorosilane or mixtures thereof prepared by hydrochlorination of silicon or of a silicon-containing material with the preferential formation of trichlorosilane
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
  • C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic Table
  • C07F7/02—Silicon compounds
  • C07F7/08—Compounds having one or more C—Si linkages
  • C07F7/0803—Compounds with Si-C or Si-Si linkages
  • C07F7/081—Compounds with Si-C or Si-Si linkages comprising at least one atom selected from the elements N, O, halogen, S, Se or Te
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00002—Chemical plants
  • B01J2219/00004—Scale aspects
  • B01J2219/00006—Large-scale industrial plants
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00002—Chemical plants
  • B01J2219/00027—Process aspects
  • B01J2219/0004—Processes in series
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/02—Apparatus characterised by their chemically-resistant properties
  • B01J2219/025—Apparatus characterised by their chemically-resistant properties characterised by the construction materials of the reactor vessel proper
  • B01J2219/0263—Ceramic
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/10—Process efficiency

Definitions

• the invention relates to a process for the preparation of a product gas mixture containing hydrogen-containing chlorosilanes within a composite process by hydrogenation of the by-product obtained in the composite process
• STC Silicon tetrachloride
• OCS organochlorosilane
• Methyltrichlorosilane with hydrogen in a pressure-operated hydrogenation reactor, the one or more reaction chambers, each consisting of a reactor tube made of gas-tight ceramic material comprises, wherein the
• the invention relates to a composite system which for carrying out the
• Hydrogen-containing chlorosilanes and in particular trichlorosilane (TCS) are important raw materials for the production of hyperpure silicon, which is needed in the semiconductor and photovoltaic industries.
• TCS trichlorosilane
• the separation of hyperpure silicon from TCS is carried out according to the technical standard from the gas phase in a Chemical Vapor Deposition (CVD) process according to the Siemens method.
• the TCS used is usually prepared by a chlorosilane process, i. H. Reaction of technical silicon with HCl (hydrochlorination of Si) at temperatures around 300 ° C in one
• methyldichlorosilane MHDCS
• MTCS methyltrichlorosilane
• organochlorosilanes are deliberately obtained by Muller-Rochow synthesis of silicon and alkyl chlorides.
• dimethyldichlorosilane as the most important starting material for the production of silicone from Si and chloromethane, MTCS is produced as coproduct in significant quantities.
• a process for the hydrodehalogenation of SiCl 4 to TCS is described.
• the reaction is advantageously carried out under pressure and in the presence of a catalyst which comprises at least one active component selected from the metals Ti, Zr, Hf, Ni, Pd, Pt, Mo, W, Nb, Ta, Ba, Sr, Ca, Mg, Ru, Rh, Ir or combinations thereof or their silicide compounds.
• a catalyst which comprises at least one active component selected from the metals Ti, Zr, Hf, Ni, Pd, Pt, Mo, W, Nb, Ta, Ba, Sr, Ca, Mg, Ru, Rh, Ir or combinations thereof or their silicide compounds.
• reactor tubes made of SiC, S13N4 or mixed systems thereof use, which are sufficiently inert, corrosion-resistant and gas-tight even at the high required reaction temperatures of 900 ° C.
• the heat input for the implementation can be made as a result of this choice of material economically by arranging the reactor tubes in a combustion chamber which is heated by combustion of natural gas.
• This reactor system has also been used to hydrogenate MTCS to a chlorosilane mixture comprising dichlorosilane (DCS), TCS and STC at process conditions typically required for hydrodechlorination of STC to TCS, allowing for high space-time yield and Selectivity to TCS.
• DCS dichlorosilane
• TCS dichlorosilane
• STC chlorosilane
• Other by-products are methane, HCl and MHDCS.
• the object of the present invention was therefore to provide a commercially applicable composite process for the preparation of hydrogen-containing chlorosilanes with efficient, most economical use of these silicon tetrachloride-containing secondary streams and methyltrichlorosilane-containing secondary streams.
• Hydrogenated reactor reacted with hydrogen to form hydrogen-containing chlorosilanes and fed after separation of the product gas mixture, the individual product streams of economic re-use, preferably in the composite process can be.
• the process allows an increase in the yield of economically valuable intermediate and end products, in particular TCS and the hyperpure silicon available therefrom for semiconductor and photovoltaic applications.
• Reactor concept of a co-owned separate application relating to a process for the combined hydrogenation of MTCS and hydrodehalogenation of STC to hydrogen-containing chlorosilanes in a pressure-operated reactor system comprising catalytically coated reactor tubes consisting of gas-tight ceramic material.
• Substance ratios of the reactants an efficient process for the hydrogenation of MTCS and hydrodehalogenation of STC to hydrogen-containing chlorosilanes with high space-time yield and selectivity with respect to TCS can be represented.
• the option of an economic heat input by arranging the gas-tight ceramic reactor tubes as reaction chambers in a fuel chamber fired with fuel gas, which is obtained as a by-product in the composite process, represents a further advantage of the method.
• the invention relates to a process for the preparation of a
• Product gas mixture comprising at least one hydrogen-containing chlorosilane within a composite process by hydrogenating at least the educts of silicon tetrachloride and methyltrichlorosilane with hydrogen in a one or more reaction chambers comprising hydrogenation, wherein the method additionally a workup of the product gas mixture by separating at least a portion of at least one product and the use of at least one part at least one of the optionally separated several products as starting material of
• Hydrogenation or as educt of at least one other method within the composite process characterized in that the hydrogenation reactor under Pressure is operated and the one or more reaction chambers each consist of a reactor tube of gas-tight ceramic material.
• hydrodehalogenation or "hydrogenation reactor” in the context of the present invention, a hydrodehalogenation reaction such as the reaction of STC with hydrogen to hydrogen-containing chlorosilanes and / or a hydrogenation reaction such as the reaction of MTCS with hydrogen to hydrogen-containing chlorosilanes or Reactor for carrying out this
• the at least one other process in the composite process according to the invention comprises at least one process selected from the group comprising a process for the hydrochlorination of silicon, a process for the deposition of silicon from the gas phase and a process for carrying out a Muller-Rochow synthesis.
• a “hydrochlorination of silicon” is to be understood as meaning a process in which Si is reacted with HCl with introduction of heat into chlorosilanes.
• “Deposition of silicon from the gas phase” in the context of the present invention refers to Process in which elemental silicon is deposited by decomposition reaction of a gaseous Si-containing compound.
• a “Mueller-Rochow synthesis” is a process for the preparation of
• Alkylhalogensilanen by catalytic conversion of at least one
• Alkyl halide preferably methyl chloride to understand with Si.
• STC-containing and / or OCS- or MTCS-containing secondary streams may be obtained.
• Silicon tetrachloride-containing secondary streams can be obtained in particular in the hydrochlorination of technical silicon to obtain TCS.
• the technical silicon used here is of low purity and will
• the hydrochlorination may be according to the prior art known methods, for. B. in a fixed bed-like reactor or a
• Fluidized bed reactor can be carried out with Si as a fixed or fluidized bed, depending on the reactor type, the temperature between 300 ° C (fluidized bed reactor) and about 1000 ° C (fixed bed reactor) is set.
• the temperature between 300 ° C (fluidized bed reactor) and about 1000 ° C (fixed bed reactor) is set.
• Hydrochlorination carried out in the fluidized bed process to increase the yield with respect to TCS.
• Product mixture of chlorosilanes in particular for the isolation of high-purity TCS, can be carried out by distillation.
• HCl formed as another by-product can be used for the hydrochlorination of Si.
• MTCS is produced as a by-product in larger quantities, in particular in the Müller-Rochow synthesis, for the production of dimethyldichlorosilane as the most important raw material for the production of silicones.
• technical silicon is typically reacted with methyl chloride in the presence of Cu-based catalysts at temperatures of 280 to 320 ° C in fluidized bed or fluidized bed reactors.
• dimethyldichlorosilane, especially MTCS, trimethylchlorosilane and MHDCS are formed.
• the different chlorosilanes can be removed by distillation Workup of the product mixture are isolated. Minor sidestreams containing MTCS also occur in the hydrochlorination of Si, as organic
• the STC- and / or MTCS-containing product mixtures from the hydrochlorination of Si, the deposition of Si from the gas phase and / or from a Müller-Rochow synthesis can thus be carried out according to methods known in the art, such as by condensation, distillation and / or or absorption, such that STC in the STC-containing side streams and MTCS in the MTCS-containing ones
• All variants of the composite process according to the invention have in common that at least part of the STC and / or MTCS by-product used as educt of the hydrogenation is at least one of the abovementioned other processes.
• the other processes preferably comprise a process for the hydrochlorination of silicon and / or a process for the deposition of silicon from the gas phase in which STC-containing side streams are obtained and a process for carrying out a Muller-Rochow synthesis in the MTCS-containing side streams.
• the secondary streams containing the STC and the secondary streams containing MTCS can be collected in each case in a reservoir and fed therefrom, with the addition of hydrogen, to the hydrogenation reactor in the composite process.
• the methyltrichlorosilane as methyltrichlorosilane educt gas and / or the silicon tetrachloride as
• SiC or S 13N4 or mixed systems (SiCN) thereof optionally wherein at least one reactor tube is filled with packing of the same material.
• SSiC pressure-sintered SiC
• SiSiC silicon-infiltrated SiC
• NSC nitrogen-bonded SiC
• the genanten materials may be coated by a thin SiO 2 layer in the pm range, which forms an additional corrosion protection layer.
• Methods are the inner walls of at least one reactor tube and / or at least a portion of the packing coated with at least one reaction of MTCS and STC with H 2 to hydrogen-containing chlorosilanes catalyzing material.
• the tubes can be used with or without a catalyst, wherein the catalytically coated tubes represent a preferred embodiment, since suitable catalysts lead to an increase in the reaction rate and thus to an increase in the space-time yield.
• the fillers are coated with a catalytically active coating, it may be possible to dispense with the catalytically active internal coating of the reactor tubes.
• the inner walls of the reactor tubes it is also preferable in this case for the inner walls of the reactor tubes to be included in the coating, since in this way the catalytically usable surface area is increased in comparison to purely supported catalyst systems (for example by means of a fixed bed).
• catalyzing material preferably composed of a composition comprising at least one active component selected from the metals Ti, Zr, Hf, Ni, Pd, Pt, Mo, W, Nb, Ta, Ba, Sr, Ca, Mg, Ru, Rh, Ir or Combinations thereof or theirs
• the composition often still contains an or a plurality of suspending agents and / or one or more auxiliary components, in particular for stabilizing the suspension, for improving the
• optionally used fixed bed can be carried out by applying the suspension to the inner walls of the one or more reactor tubes and / or the surface of the packing, drying the applied suspension and then annealing at a temperature in the range of 500 ° C to 1500 ° C under inert gas or hydrogen ,
• the at least one reaction tube is usually arranged in a heating chamber.
• the introduction of the heat required for the reaction can by combustion of a fuel gas, in particular from within the
• Combined natural gas take place in the heating chamber.
• the burner In order to achieve a uniform temperature control when heating by means of fuel gas and to avoid local temperature peaks on the reactor tubes, the burner should not be aimed directly at the pipes. For example, they can be distributed and aligned over the heating chamber so that they point into the free space between parallel reactor tubes.
• the hydrogenation reactor can also be connected to a
• the integrated Heat exchanger tube may be at least partially coated with the above-described catalytically active material.
• the disruptive deposition of Si-based solids which typically occurs in the reaction of organochlorosilanes such as MTCS with H 2 at reaction temperatures above 800 ° C., can advantageously be significantly reduced by suitable combination with the hydrodehoiogenation of STC with hydrogen during the operation of the hydrogenation reactor.
• suitable combination with the hydrodehoiogenation of STC with hydrogen during the operation of the hydrogenation reactor.
• the various combinations described below are suitable combinations
• At least one, optionally each, reaction space is alternately a)
• the hydrogenation of STC on the one hand and MTCS on the other hand preferably takes place simultaneously in separate reaction spaces.
• STC MTCS (or OCS) in a molar ratio of 50: 1 to 1: 1, preferably from 20: 1 to 2: 1, and STC: H 2 from 1: 1 to 8: 1, preferably from 2: 1 to 6: 1, and MTCS (or OCS): H 2 from 1: 1 to 8: 1, preferably from 2: 1 to 6: 1.
• the changes between the supply of STC on the one hand and MTCS or OCS on the other hand, in each case in admixture with the hydrogen, to the individual Reaction spaces can be carried out simultaneously for all reaction spaces or independently of each other.
• the times of change can be determined, in particular, as a function of changes in the pressure and / or material balance measured in at least one reaction space.
• These parameters may be suitable for indicating the formation of a significant amount of solid deposits, or conversely, the substantial degradation of formed solid deposits in the reactor.
• solid deposits in a reaction space can reduce its flow cross-section and thus cause a pressure drop.
• the pressure measurement can be carried out by any methods known in the art, e.g. B. by means of suitable mechanical, capacitive, inductive or piezoresistive pressure gauges. Substantial degradation of Si-based
• Solid deposits in a reaction space can, for. Example, at an increased HCl concentration in the product gas mixture leaving this reaction space, be apparent, since the consumption of HCl is reduced by the Hydrochlorierungsre force with silicon due to the decreasing availability of the latter.
• the composition of the product gas may be analyzed by known analytical techniques, e.g. B. be measured by gas chromatography in combination with mass spectrometry.
• the change of the feed of the educts to the individual reaction chambers in the manner described above can be carried out by means of a suitable conventional control valve system.
• the molar ratio of H 2 to MTCS is typically adjusted to be in the range of 1: 1 to 8: 1, preferably 2: 1 to 6: 1, as the reactants are fed to the reaction spaces in this reactor mode molar ratio of H 2 to STC is usually set in a range of 1: 1 to 8: 1, preferably 2: 1 to 6: 1.
• the methyltrichlorosilane and the silicon tetrachloride are simultaneously fed to at least one common reaction space in a mixture with the hydrogen for hydrogenation, the molar ratio of methyltrichlorosilane to Silicon tetrachloride in a range of 1:50 to 1: 1, the molar ratio of methyltrichlorosilane to hydrogen in a range of 1: 1 to 8: 1 and the molar ratio of silicon tetrachloride to hydrogen in a range of 1: 1 to 8: 1 set becomes.
• the reaction thus takes place in a single common reaction space.
• the silicon tetrachloride in admixture with the hydrogen is fed to at least one first reaction space and the methyltrichlorosilane, optionally in admixture with the hydrogen, to at least one second reaction space for hydrogenation, the product gas mixture leaving the at least one first reaction space being at least a second reaction space is additionally supplied.
• Intermediate in the hydrogenation of MTCS in the at least one second reaction space deposited silicon can be degraded in the sequence by the HCI-containing product gas mixture from the at least one first reaction space again and the operation of the hydrogenation reactor in this way permanently stable upright.
• Reaktorverscnies are also supplied exclusively together with STC the reactor via the at least one first reaction space.
• the at least one second reaction space can then with an MTCS stream to the
• Product gas mixture is supplied from the at least one first reaction space fed. Hydrogen contained in said product gas mixture and unreacted in the at least one first reaction space can then react with MTCS in the at least one second reaction space. However, it is preferred that hydrogen is supplied to the reactor both together with STC, feeding the at least one first reaction space, as well as together with MTCS, feeding the at least one second reaction space. This allows a more independent setting of advantageous molar ratios for the hydrodehalogenation of STC in the first reaction space and for the
• the molar ratio of H 2 to STC for the reaction in the at least one first reaction space is preferably set in a range from 1: 1 to 8: 1, preferably 2: 1 to 6: 1.
• the molar ratio of hydrogen to MTCS is preferably set in the reaction in the at least one second reaction space to be in the range from 1: 1 to 8: 1, preferably 2: 1 to 6: 1.
• All variants of the process according to the invention have in common that the hydrogenation in the hydrogenation reactor typically at a pressure of 1 to 10 bar, preferably from 3 to 8 bar, more preferably from 4 to 6 bar, a temperature greater than 800 ° C, preferably at a temperature in the range of 850 ° C to 950 ° C, and gas streams having a residence time in the range of 0.1 to 10 s, preferably from 1 to 5 s,
• the product gas mixture formed in the process according to the invention by the hydrogenation of STC and MTCS with H 2 typically comprises at least HCl and methane in addition to at least one hydrogen-containing chlorosilane.
• H 2 typically comprises at least HCl and methane in addition to at least one hydrogen-containing chlorosilane.
• hydrogen-containing chlorosilanes in addition to oligomeric and monomeric chlorosilanes, in particular hydrogen-containing
• Chlorosilanes z. SiH 4 , SiCl 3 , SiCl 2 H 2 (DCS), STC and TCS, organochlorosilanes such as MTCS, MHDCS and dimethyldichlorosilane.
• MTCS SiCl 3
• MHDCS metal-organochlorosilane
• Product gas mixture may be present.
• various chlorinated boron compounds may also be included in the product gas mixture.
• the product gas mixture comprising the reaction of STC and MTCS with hydrogen in the hydrogenation reactor typically comprises at least three or all products from the group comprising HCl, methane, hydrogen,
• Methyltrichlorosilane Frequently, the product gas mixture also contains high boilers.
• the components contained in the product gas mixture are usually isolated in the sequence as pure as possible and then their further
• the workup of the product gas mixture may vary depending on the composition of the product gas mixture and must meet the requirements of the respective process and composite process. Suitable embodiments and apparatuses of usable physical-chemical separation processes, such as
• Condensation, freezing, distillation, absorption and / or adsorption may, for. B. Ullmann's Encyclopedia of Industrial Chemistry, 4th ed., Verlag Chemie GmbH, Weinheim, Volume 2, page 489 ff. Are removed. Specific
• Product is used as a reactant of hydrogenation or as a starting material of another process within the composite process.
• unreacted starting materials can advantageously be attributed to the hydrogenation reactor.
• Hydrogen obtained by working up the product gas mixture is thus typically at least partially used as starting material for the hydrogenation in the composite process according to the invention.
• silicon tetrachloride and / or methyltrichlorosilane are usually at least partially used as reactants of the hydrogenation.
• HCl obtained by working up the product gas mixture may be used at least partially as a starting material in a process for the hydrochlorination of Si within the composite process, as long as a process for the hydrochlorination of Si is part of the composite process. In this case also from the
• Product gas mixture separated high boilers use at least partially as reactants for the hydrochlorination of Si within the composite process. About that In addition, these can be taken from the composite process at least partially as products for re-use or disposal.
• Trichlorosilane obtained by working up the product gas mixture may be used, at least in part, as a starting material in a process for depositing silicon from the gaseous phase within the composite process, provided that a process for depositing silicon from the gaseous phase is part of the
• Composite method is, and / or the composite method at least partially taken as a product for further use.
• the inventive method may optionally be obtained in admixture with TCS, the composite method is preferably at least partially as a product
• downstream can be a
• methane obtained by working up the product gas mixture can advantageously be used, at least in part, as fuel for heating the hydrogenation reactor.
• the separated methane-containing gas in the composite process according to the invention at least one burner, which is directed into the heating chamber, in which the reaction chambers of the hydrogenation reactor are arranged, fed and burned with the addition of air or oxygen.
• the invention further relates to a composite system for carrying out a process for producing a product gas mixture containing at least one hydrogen-containing chlorosilane by working up the product gas mixture by separating at least one part of at least one product and using at least one part of at least one of the optionally separated products in the process, characterized in that the composite system comprises:
• This composite system preferably serves for carrying out the composite method according to the invention.
• STC-containing side streams and MTCS-containing secondary streams can be collected in each case in a reservoir and from there to the hydrogenation reactor for
• Implementation can be supplied with additionally fed hydrogen.
• hydrogen in a particular embodiment of the process according to the invention in the workup of the product gas mixture is typically
• the product gas mixture of the hydrogenation which initially contains at least several of the components H 2 , HCl, CH, DCS, TCS, STC, MHDCS, MTCS and high boilers, to temperatures less than -70 ° C, the volatile constituents contained therein of the condensing Components are separated.
• Product gas mixture is then contacted, preferably comprises at least one chlorosilane.
• the contact with the absorption medium can be carried out in such a way that the gas mixture is passed over a fluidized bed. HCl and chlorosilanes contained in the gas mixture can thus be removed by absorption.
• the gas stream leaving the absorption unit then contains H 2 , CH 4 and other exhaust gases and can subsequently be passed through a suitable adsorption medium for adsorptive separation.
• adsorption medium is suitable
• activated carbon Methane and other exhaust gases are adsorbed by the activated carbon, while the hydrogen is not adsorbed by this adsorption medium and thus in a purified form from contact with
• Activated carbon can be obtained. After at least partial saturation of the
• Adsorption medium with CH 4 and other exhaust gases Adsorption medium with CH 4 and other exhaust gases, however, the adsorbates can be released gaseous by desorption and fed in the sequence of their further use.
• the desorption can be carried out, for example, thermally by heating the adsorption medium.
• the CH 4 -containing exhaust gas stream is preferably fed to a burner for energy and heat generation.
• the condensate from the cooling of the original product gas mixture of the hydrogenation to temperatures below -70 ° C, which contains one or more of the components HCl, DCS, TCS, STC, MHDCS, MTCS and high boilers, is typically used for the separation of a subsequent distillation
• Product gas mixture is used, this is preferably combined after the absorption step with the condensate for distillative work-up.
• HCl can be separated off by at least the steps:
• Si-based compounds and high-boiling compounds are in the
• Multi-stage distillation of the distillation residue from the pressure distillation thus, high boilers can be separated here as a residue of the first distillation stage.
• the multi-stage distillation of the distillation residue of the pressure distillation may be four or more
• a mixture comprising silicon tetrachloride and methyltrichlorosilane can in this case as a residue of the second
• Product gas mixture in the composite system may thus comprise one or more of the following components:
• Product gas mixture with an absorption medium preferably an absorption medium comprising at least one chlorosilane,
• Product gas mixture an adsorption medium, preferably activated carbon,
• a unit for the multi-stage distillation of the residue of pressure distillation A special suitable embodiment of the subsystem for processing the
• FIG. 1 shows by way of example and schematically a composite system according to the invention.
• FIG. 2 shows, by way of example and schematically, a possible variant of a unit for working up the product gas mixture, which after hydrogenation of STC and MTCS with hydrogen in the hydrogenation reactor according to the invention
• the composite system 1 shown in Figure 1 comprises a subsystem 2 to
• the composite system comprises a subsystem 6 for
• incurred methyltrichlorosilane side streams which are passed via a line 7 in a reservoir 8 and collected there.
• the sidestreams containing the STC and the MTCS-containing sidestreams are fed from their reservoirs via one or possibly a plurality of line (s) 9 with the addition of hydrogen via one or optionally a plurality of further line (s) 10 to the hydrogenation reactor 11 for hydrogenation.
• the resulting product gas mixture is transferred via a line 12 from the hydrogenation reactor to a unit 13 for working up the product gas mixture in which a material separation of the product gas mixture takes place.
• Via lines 14, 15, STC and MTCS or H 2 separated off from the workup of the product gas mixture are fed to the hydrogenation reactor for reuse as starting materials.
• Methane-containing exhaust gas from the workup of the product gas mixture can be fed via a line 16 to at least one burner for heating the hydrogenation reactor.
• Separated HCl and a part of the isolated high boiler are fed via a line 17 in the unit 2 for the hydrochlorination of silicon as starting materials during the essential part of the trichlorosilane obtained by the work-up of the product gas mixture of the hydrogenation via another line 18 of the unit 3 for the deposition of silicon from the gas phase as Feedstock is supplied.
• Further lines 19, 20, 21 can also be used to separate the composite system 1 in each case by working up the product gas mixture
• DCS / TCS mixture, methyldichlorosilane-containing mixture or high boiler are taken and fed to another use outside the composite process.
• the partial system 13 shown in FIG. 2 for working up the product gas mixture comprises a cooling unit 22, in which the product gas mixture fed from the hydrogenation reactor 11 via a line 12 for the condensation of the non-volatile
• Product gas mixture are fed via a line 23 of an absorption unit 24 and fed there with a via another line 25
• Absorption medium comprising at least one chlorosilane brought into contact.
• the portions of the gas mixture not absorbed by the absorption medium are fed to a downstream adsorption unit 27 where they are brought into contact with activated carbon as the adsorption medium.
• Methane-containing adsorbate can be desorbed after at least partial saturation of the activated carbon and via a corresponding line 16 from the unit to
• Pressure distillation unit 30 supplied. HCl can be over the head of the
• Distillation column 33 is supplied. About a line 17,21 is the
• the top stream of the first distillation column 33, however, over a line 34 is transferred to a second distillation column 35.
• the second distillation column 35 can be removed via a further line 14, a STC and MTCS-containing mixture as the distillation residue.
• the top stream of the second distillation column 35 is in turn transferred 36 to a third series-connected distillation column 37.
• Distillation column 37 containing a mixture of DCS and TCS is discharged via a further line 19 for further use during the
• Destillation column 39 is transferred. As the distillation residue of this fourth distillation column 39, a MHDCS-containing mixture is then removed via a corresponding line 20 while TCS can be taken off at the top of the fourth distillation column 39 and fed via another line 18 to its further use.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Silicon Compounds (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Separation Of Gases By Adsorption (AREA)

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• 2011
  • 2011-03-16 DE DE102011005647A patent/DE102011005647A1/de not_active Withdrawn
• 2012
  • 2012-01-27 JP JP2013558337A patent/JP2014519460A/ja not_active Withdrawn
  • 2012-01-27 EP EP12703737.2A patent/EP2686099A1/de not_active Withdrawn
  • 2012-01-27 US US14/005,360 patent/US20140212352A1/en not_active Abandoned
  • 2012-01-27 CN CN2012800131632A patent/CN103402623A/zh active Pending
  • 2012-01-27 CA CA2829701A patent/CA2829701A1/en not_active Abandoned
  • 2012-01-27 KR KR1020137024033A patent/KR20140008372A/ko not_active Application Discontinuation
  • 2012-01-27 WO PCT/EP2012/051353 patent/WO2012123159A1/de active Application Filing
  • 2012-03-13 TW TW101108463A patent/TW201249744A/zh unknown

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