Thermal condensation reactor

Abstract

Described herein is a thermal condensation reactor and a process for using the same. The described thermal condensation reactor includes a heat transfer chamber, the heat transfer chamber being a fluidized bed with a fluidizing gas flow in a first direction, the heat transfer chamber having a plurality of heating zones that can be maintained at different temperatures, and a plurality of reaction tubes disposed within the heat transfer chamber in a second direction perpendicular to the fluidizing gas flow, each reaction tube having a reaction gas flow passing through a plurality of heating zones.

Description

Background Art

[0001] Cross - reference to related applications This application claims priority to U.S. Provisional Application No. 62 / 908,802, filed on October 1, 2019, the entire content of which is incorporated herein by reference.

[0002] Certain chemical reactions, such as thermal condensation or dehydrochlorination reactions, require high temperatures and may involve corrosive reactants. One such reaction is the gas - phase reaction between trichlorosilane (HSiCl3) and vinyl chloride (H2C = CHCl), which does not proceed rapidly until the temperature exceeds 500 °C. This reaction liberates hydrogen chloride (HCl(g)), which is corrosive to most metallurgies (e.g., even those containing high levels of Ni, Cr, and Mo for resistance). Further, at these temperatures, trichlorosilane reacts with nickel - containing metals to form intermetallic silicon compounds, which are then etched by HCl, leading to an increase in the corrosion / pitting rate. Unfavorable side reactions can occur, for example, when trichlorosilane is in excess, causing the decomposition of vinyl chloride into soot. Soot can lead to operation and maintenance problems. Similarly, when trichlorosilane is fed stoichiometrically in excess, the formation of 1,2 - bis(trichlorosilyl)ethane and other heavy silicon - based compounds becomes significant, resulting in unwanted chlorosilanes.

[0003] Accordingly, there is a need for a thermal condensation reactor that avoids these problems and a process using the same.

Summary of the Invention

[0004] In this specification, a thermal condensation reactor (and the process using the same) is described. The thermal condensation reactor described herein is a heat transfer chamber, wherein the heat transfer chamber is a fluidized bed having a fluidizing gas flow in a first direction, and the heat transfer chamber has a plurality of heating zones that can be maintained at different temperatures, a heat transfer chamber, and a plurality of reaction tubes disposed in the heat transfer chamber in a second direction perpendicular to the fluidizing gas flow, each reaction tube having a reaction gas flow passing through a plurality of heating zones, and a plurality of reaction tubes. A process for producing vinyltrichlorosilane and other alkenyl-functional halosilanes is also described, the process comprising premixing vinyl chloride and hydride-functional halosilane to produce a reaction gas, introducing the reaction gas into a plurality of reaction tubes disposed horizontally with respect to the base of the fluidized bed, and passing the reaction gas through a plurality of heating zones of the fluidized bed, the plurality of heating zones being maintained at different temperatures.

Brief Description of the Drawings

[0005]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0006] FIG. 1 is a side perspective view of a thermal condensation reactor 100 with the top portion removed. The reactor 100 includes a heat transfer chamber 102. As described below, the heat transfer chamber 102 is preferably a fluidized bed chamber. The heat transfer chamber 102 includes a plurality of heating zones 102a - c. The heating zones can be maintained at different temperatures. For example, each heating zone has its own temperature control. In one embodiment, the capabilities of the heating zones are utilized to supply relatively more energy during the initial stages of an exothermic reaction and relatively less energy during subsequent stages of the reaction, and further, for example, to cool the reaction as the exotherm intensifies. Thus, the ability to maintain different temperatures is intended to be construed broadly and includes, for example, maintaining an exothermic reaction at substantially the same temperature throughout the entire reaction cycle, which necessarily includes holding different heating zones at different temperatures. Although three heating zones 102a - c are illustrated, it should be understood that the heat transfer chamber 102 can include any number of heating zones so long as the heat transfer chamber 102 has at least two heating zones. The heating zones can be created by heating sources such as a series of resistance coil heating elements external to the heat transfer chamber (e.g., heating source 400 in FIG. 4), a pulse combustion heater unit inside the heat transfer chamber, etc. The heating zones can remove some heat from the fluidized solids through the use of either a heat pipe cooled by a heat transfer fluid or a submerged heat exchanger while simultaneously maintaining the ability to supply heat to the process. The heating zones can be created by (e.g., among other things) the fluidizing gas flow rate. Each of the heating zones 102a - c has its own logic control to achieve the desired temperature within each respective heating zone.

[0007] To reduce the heat loss of zones that require heat input, refractory materials and other insulating materials can be used. The location of the materials can vary depending on the technology used. For example, when heat input is driven by a pulse combustion unit, the refractory material can be employed inside the chamber, but when a resistance heating element is used, it is advantageous to use refractory outside the heat transfer chamber. Internal refractory materials have additional advantages against corrosion, but corrosion can also be addressed by applying surface-hardened metal cladding to the chamber or applying a ceramic coating to the metal surface by high-velocity oxygen fuel (HVOF).

[0008] The thermal condensation reactor 100 includes a fixed inlet head 104. The stationary inlet head 104 is attached to the heat transfer chamber 102. The reactants enter the fixed head 104 (e.g., the inlet side).

[0009] The thermal condensation reactor 100 includes a plurality of reaction tubes 106. For the sake of simplicity of illustration, a single reaction tube numbered 106 is shown, but since multiple tubes are contemplated, reference is made to the reaction tubes 106 throughout the present disclosure. The plurality of reaction tubes 106 are in fluid communication with the fixed head 104 and extend through the heat transfer chamber 102. Thus, the reactants enter the plurality of reaction tubes 106 at the fixed head 104 and are conveyed through the plurality of reaction tubes in the heat transfer chamber 102 to receive a plurality of heating zones 102a - c. The reactants are sealed from the heat transfer chamber 102.

[0010] Differential thermal expansion between the tubes and the body of the heat transfer chamber and the support must be addressed. The thermal condensation reactor 100 includes a floating head 108. The plurality of reaction tubes 106 exit the heat transfer chamber 102 and enter the floating head 108 (e.g., the outlet side). Thereby, the reaction products are collected in the floating head 108. A cooling transfer unit 110 surrounds the floating head 108. The cooling transfer unit 110 can be used to control the temperature of the reaction products. In one embodiment, the function of the floating head can be replaced with a flexible tube sheet.

[0011] The fixed head 104 includes a bonnet 112 that is attached to the heat transfer chamber 102. A gasket 113 is positioned between the bonnet 112 and the heat transfer chamber 102. The gasket 113 seals the connection between the bonnet 112 and the heat transfer chamber 102. In some embodiments, the primary function of the gasket 113 is to prevent the fluidized bed media from entering the bonnet 112. Accordingly, various gasket designs are contemplated, including, for example, gaskets, double gaskets, or ring joints. The details of a particular gasket depend on the thermal expansion mitigation strategy for the fluidized bed media.

[0012] As described herein, the bonnet 112 cooperates with other components to define one or more plenums. The primary gas supply inlet 114 is disposed within the bonnet 112. Reactants enter the plenum defined by the bonnet 112 through the primary gas supply inlet 114.

[0013] The inlet supply gas manifold 116 and the reactor tube plate surface 118 are disposed inside the bonnet 112. The reactor tube plate surface 118 abuts the heat transfer chamber 102. The inlet supply gas manifold 116 and the reactor tube plate surface 118 are disposed in the same plane as each other and extend to the edge of the bonnet 112. The inlet supply gas manifold 116 and the reactor tube plate surface 118 each have a plurality of ports numbered 116a and 118a, respectively, for receiving a plurality of reaction tubes 106. Each of the ports 116a and 118a receives a respective reaction tube 106. Any number of reaction tubes 106 are contemplated depending on space limitations, reactor capacity, and other considerations.

[0014] As will be described in more detail below with respect to FIG. 3, the plurality of reaction tubes 106 are sealed and disposed within ports 116a and 118a. Thus, when assembled, the components cooperate to define separate plenums that are not in fluid communication, such as a first plenum (e.g., plenum 319 in FIG. 3) between the bonnet 112 and the first side of the inlet supply gas manifold 116, and a second plenum (e.g., plenum 321 in FIG. 3) between the second side of the inlet supply gas manifold 116, the bonnet 112, and the reactor tube plate surface 118.

[0015] Optionally, the shroud gas port 120 is fluidly combined with a second plenum defined between the inlet supply gas manifold 116, the bonnet 112, and the reactor tube plate surface 118. The shroud gas port 120 introduces a non-reactive gas (e.g., shroud gas) into the second plenum (e.g., plenum 321 in FIG. 3). The shroud gas can act as a diluent and / or (e.g., for the plurality of reaction tubes 106) to manage pressure. The reactor tube plate surface 118 is sealed from the heat transfer chamber 102 as will be described below with respect to FIG. 3 so that the second plenum is not in fluid communication with the heat transfer chamber 102.

[0016] The thermal condensation reactor 100 includes a plurality of plates 122a - e. The plurality of plates 122a - e are disposed within the heat transfer chamber 102 to support the plurality of reaction tubes 106. For example, each of the plurality of plates 122a, 122b, 122c, 122d, 122e includes a plurality of openings. Each of the plurality of openings is configured to receive a respective one of the plurality of reaction tubes 106. The plurality of reaction tubes 106 are supported by corresponding openings in the plurality of plates 122a, 122b, 122c, 122d, 122e. As shown, the bonnet 112 is attached to the plate 122a adjacent to the reactor tube plate surface 118.

[0017] Although five plates 122a - e are illustrated, it is understood that any number of plates may be contemplated. It should be noted that the arrangement of plates 122b - d does not necessarily correspond to the boundaries of heating zones 102a - c. Rather, the boundaries of the heating zones are determined by the position of an external heat source (not shown).

[0018] Plates 122a - e can be fixed to the heat transfer chamber 102 in various ways, for example, by mechanical fasteners (e.g., plates 122a, 122b, 122d, and 122e), or by a movable support (e.g., plate 122c with respect to the roller support 210 (as described below with respect to FIG. 2)). In one example of a mechanical fastener, a plurality of tracks 123a - b fix plates 122b and 122d within the heat transfer chamber 102. Tracks 123a - b slidably engage plates 122b and 122d and can, for example, allow for thermal expansion.

[0019] A plurality of baffles 124a - b are disposed within the heat transfer chamber 102. The plurality of baffles 124a - b support the operation of the heat transfer chamber 102 as a fluidized bed. Additional baffles (not shown) may be disposed within the heat transfer chamber 102. It is understood that the heat transfer chamber 102 may include any number of baffles similar to baffles 124a - b. It is also understood that plates 122b - d also act as baffles during operation, as will be described later.

[0020] The plurality of gas ports 126a - d are disposed in fluid communication with the heat transfer chamber 102. The plurality of gas ports 126a, 126b, 126c, and 126d are configured to introduce a non - reactive gas into the heat transfer chamber 102. Although any number of gas ports may be contemplated, as will be described later, it is understood that it is beneficial to have at least one gas port associated with each heating zone (e.g., heating zones 102a - c). Although not shown, a distributor plenum (e.g., a sparger, a sintered metal perforated plate gas distributor, or a porous plate) may be disposed inside the heat transfer chamber 102 above the gas ports 126a - d.

[0021] Although not shown, the heat transfer chamber 102 has a top portion for surrounding the heat transfer chamber 102. The top portion may have a heating element for controlling the temperature. The top portion includes one or more recovery plenums for recovering the non - reactive gas introduced through the gas ports 126a - d. The one or more recovery plenums may be in fluid communication with an exhaust device (e.g., a common exhaust device).

[0022] The plurality of drain ports 128a - d are disposed in fluid communication with the heat transfer chamber 102 for discharging solids from the heat transfer chamber (e.g., although not shown, the heat transfer chamber may include a fluidized bed of solid particles, preferably solid particles in the form of powder of Geldart group A, etc.). It is understood that any number of drain ports may be contemplated.

[0023] For structural support, a plurality of supports 130a - e are disposed below the heat transfer chamber 102. It is understood that any number of supports may be contemplated.

[0024] The cooling transfer unit 110 has a gas port 126e, a drain port 128e, and a support 130f, has the same reference numerals as those described with respect to the heat transfer chamber 102, and operates substantially similarly. Although not shown, the cooling transfer unit 110 may include solid particles, preferably a fluidized bed of solid particles (such as in the powder form of Geldart group A, for example). The fluidization of this zone reduces interference with thermal expansion and reduces the amount of buffering required to maintain fluidization in the previous zone.

[0025] The vapor outlet 132 is in fluid communication with the floating head 108 and is disposed within the cooling transfer unit 110. Reaction products (such as including any shroud gas, for example) from the plurality of reaction tubes 106 are recovered through the vapor outlet 132.

[0026] Figure 2 is a cross-sectional view of FIG. 1 taken along line 2-2. A portion of the reactor tube plate surface 118 and the plate 122e has been removed for simplicity of illustration.

[0027] The roller support 210 attaches the plate to the heat chamber and extends between the plate 122c and the heat transfer chamber 102, for example to allow for thermal expansion of the plate.

[0028] The floating head 108 includes a plate 222 for supporting the plurality of reaction tubes 106. A seal ring 224 is disposed between the plate 222 and the plate 122 / heat transfer chamber 102 to seal reaction products within the floating head from the cooling transfer unit 110 and the heat transfer chamber 102.

[0029] The roller support 226 movably connects the floating head 108 to the heat transfer chamber 102. For example, the floating head 108 may float at the rear of the heat transfer chamber 102 such that the position of the floating head relative to the heat transfer chamber can vary in one direction (such as by thermal expansion).

[0030] FIG. 3 is an enlarged cross-sectional view of a reaction tube 306 (such as reaction tube 106 shown in FIG. 1, for example). The reaction tube 306 extends from the bonnet 312 into the heat transfer chamber 302 and passes through an inlet supply gas manifold 316, a reactor tube plate surface 318, and a plate (not shown), all of which may be substantially similar to the corresponding named components of FIG. 1. Although not shown, it is understood that a plurality of reaction tubes are contemplated.

[0031] The reaction tube 306 includes a gas injection port 306a that extends axially from a reaction tube liner 306b. In one embodiment, the gas injection port 306a is fitted sufficiently loosely within the reaction tube liner 306b to allow gas to pass between the outer and inner surfaces of their respective walls. Reactants within a first plenum 319 defined between the bonnet 312 and the inlet supply gas manifold 316 enter the gas injection port 306a. A sealing connector 334 is disposed within the inlet supply gas manifold 316 that engages the gas injection port 306a. The connector 334 can comprise a plurality of sealing devices such as a sealing gland or a compression fitting. Accordingly, the first plenum 319 is sealed against a second plenum 321 defined between a second surface on the same plane as the inlet elliptical head, the bonnet 312, and the reactor tube plate surface 318. Optionally, a shroud gas is introduced into the second plenum 321.

[0032] The sealing gland (or stuffing box) 336 is disposed on the reactor tube plate surface 318 and engages with the reaction tube liner 306b. The sealing gland 336 enables an airtight seal between the heat transfer chamber 302 and the second plenum 321. Commercially available sealing glands can be obtained, inter alia, from Conax Technologies (Buffalo, New York, USA). The compressible sealant 336a (e.g., flexible graphite, etc.) engages with the outside of the reaction tube liner 306b. The second plenum 321 is sealed with respect to the heat transfer chamber 302. The passage 336b extends through the sealing gland 336 to the reaction tube liner 306b. The gas in the second plenum, such as the shroud gas, can enter the reaction tube liner 306b through the passage 336b of the sealing gland 336.

[0033] Referring to FIG. 4, the heating source 400 is disposed outside the heat transfer chamber 402 (e.g., the heat transfer chamber 102 shown in FIG. 1, etc.). The heating source 400 includes an array of resistance coil heating elements 404. The support 406 mechanically fixes the resistance coil heating elements 404. For example, the support 406 can be fixed to the heat transfer chamber 402 to receive the resistance coil heating elements 404. A plurality of heating sources (not shown) can be used to create separate controllable heating zones (e.g., the heating zones 102a - c described with respect to FIG. 1). Commercially available resistance coil heating elements can be obtained, inter alia, from Keith Company, Pico Rivera, California, USA, or Armstrong Chemtec Group, Coatesville, Pennsylvania, USA.

[0034] Referring to FIG. 5, an enlarged plan view of the roller support 226 is illustrated. For simplicity of illustration, a portion of the plate 122e has been removed. The roller support 226 includes a support member 502 attached only to the floating head 108. The roller member 504 of the roller support 226 is movably engaged with the support member 502 to enable the floating head 108 to move along an axis defined by the plurality of reaction tubes 106. The track member 506 of the roller support 226 is attached to the heat transfer chamber 102 to fix the roller member 504.

[0035] During operation, the thermal condensation reactor 100 may find use as a multi-zone fluidized bed assisted heating / cooling device for thermal condensation or dehydrochlorination reactions. For example, in one embodiment, the thermal condensation reaction may be the thermal condensation of a reaction gas comprising a hydridofunctional halosilane and an alkenyl halide, and the thermal condensation forms an alkenylfunctional halosilane. For example, the hydridofunctional halosilane has the chemical formula R w H x SiX (4-w-x) where the subscript, subscript w is from 0 to 2, the subscript x is from 1 to 3, the quantity (w + x) is from 1 to 3, each R is an independently selected monovalent hydrocarbon group of 1 to 18 carbon atoms without aliphatic unsaturation, and each X is an independently selected halogen atom such as F, Cl, Br, or I, alternatively Cl or Br, and alternatively Cl. The monovalent hydrocarbon group of R can be alkyl (e.g., methyl, ethyl, or hexyl, alternatively methyl), or aryl (e.g., phenyl, tolyl, or xylyl, alternatively phenyl). The alkenyl halide has the chemical formula R’X amay have, where the subscript a is the valence from 1 to a maximum of R', R' is an alkenyl functional group such as vinyl, vinylidene, allyl, or hexenyl, and X is as described above. Exemplary hydride-functional halosilanes include monochlorosilane (H3SiCl), dimethylchlorosilane [(CH3)2HSiCl], disilane dichloride (H2SiCl2), and trichlorosilane (HSiCl3). Exemplary alkenyl halides include vinyl chloride, vinylidene chloride, allyl chloride, and hexenyl chloride. The alkenyl-functional halosilane that can be prepared in the thermal condensation reactor 100 has the chemical formula R' u R y H z SiX (4-y-z) may have, where the subscript u is 1, 2, or 3 (alternatively 1), the subscript y is 0, 1, or 2, the subscript z is 0, 1, or 2, and the quantity (u + y + z) is 1 to 3. The alkenyl-functional halosilane that can be prepared in the thermal condensation reactor 100 includes vinyltrichlorosilane (for example, when the hydride-functional halosilane is HSiCl3 and the alkenyl is vinyl, the halide is vinyl chloride), or dimethylvinylchlorosilane [(CH3)2(CH2=CH)SiCl] (for example, when the hydride-functional halosilane is dimethylchlorosilane and the alkenyl is vinyl, the halide is vinyl chloride). The gas-phase reaction between trichlorosilane and vinyl chloride does not proceed rapidly until the temperature exceeds 500°C.

[0036] The thermal condensation reactor 100 delivers a temperature exceeding 500°C, which is required to operate the reaction with good conversion per pass, and at the same time suppresses the influence of exotherm associated with the process chemicals. To achieve this, a plurality of reaction tubes 106 are used (e.g., fitted with an internal liner having chemical resistance to HCl and good thermal conductivity (e.g., isomolded graphite, carbon fiber / carbon composite, isomolded graphite coated with SiC, or silicon carbide such as Saint-Gobain Hexaloy® SiC, etc.)). Since the coefficient of thermal expansion of the liner is smaller than that of the reaction tube metallurgy, the liner needs to slide during growth. This sliding can be assisted by using a flexible graphite film and / or saddle disposed at the bottom of the liner. Also, the length of the internal liner should preferably be longer than the length of the tube. The plurality of reaction tubes 106 are arranged parallel to the flow of the reactants and orthogonal (e.g., perpendicular or substantially perpendicular (e.g., ±15 degrees from perpendicular)) to the flow of the fluidizing gas. As illustrated, this results in a horizontal flow of the reactants and a vertical flow of the fluidizing gas. The horizontal configuration provides advantages when mechanically supporting the plurality of reaction tubes 106 and during maintenance operations. The use of silicon carbide can provide sufficient oxidation resistance to enable the oxidation treatment of the deposited soot that accumulates over time during the process. As part of the maintenance cycle, the addition of hydrogen at a temperature exceeding 600°C can also be employed (e.g., for methanating soot-like compounds into vapor form).

[0037] The liner is fixed, for example (as shown in FIG. 3) by a sealing gland 336 to prevent the flow of reactants (e.g., reaction gas) to the outside of the liner (e.g., to the heat transfer chamber 102).

[0038] Optionally, the shroud gas is co-fed to the reactor. In the case of the reaction of trichlorosilane and vinyl chloride, the use of silicon tetrachloride (SiCl4) as the shroud gas reduces the movement of carbon species near the reaction tube wall, while providing the advantage as a diluent that can reduce the Si-H / Si-Cl rearrangement reaction leading to dichlorosilane and vinyldichlorosilane in the effluent. The shroud gas consists of organohalosilanes, most preferably the halogenated products (HX) of hydride-functional halosilane feedstocks and hydrogen halides. For example, in the case of a reaction involving trichlorosilane and vinyl chloride, since the halogenated product of trichlorosilane (HSiCl3) and HCl is silicon tetrachloride (SiCl4), silicon tetrachloride is used as the shroud gas. Similarly, in the case of a reaction involving dimethylchlorosilane and vinyl chloride, dimethyldichlorosilane [(CH3)2SiCl2] is used. The shroud gas is introduced via the shroud gas port 120 into a second plenum defined between the inlet feed gas manifold 116, the bonnet 112, and the reactor tube plate surface 118. The shroud gas flows around the gas injection port 306a for each reaction tube through the passage 336b and extends to the reaction tube liner 306b through the sealing gland 336. The passage 336b is configured with a sufficient pressure drop to facilitate a well-balanced distribution of the shroud gas among all of the plurality of reaction tubes 106. Similarly, an orifice plate is present at the inlet for each gas injection port 306a containing the vinyl chloride / trichlorosilane feed mixture to facilitate a uniform distribution of the gas among the individual reaction tubes 106.

[0039] The plurality of reaction tubes 106 extend from the bonnet 112, pass through the heat transfer chamber 102, and terminate at the floating head 108. The heat transfer chamber 102 is a heating trough having a plurality of heating zones 102a - c. Inside the heat transfer chamber 102, a fluidizing gas (e.g., nitrogen, etc.) is used to fluidize the solid medium to form a fluidized bed. As illustrated, the fluidizing gas travels perpendicular to the plurality of reaction tubes 106. The fluidizing gas (e.g., nitrogen, etc.) is delivered to the heat transfer chamber 102 via a plurality of gas ports 126a - d and may pass through a sparger, a sintered metal perforated plate, or a gas distributor. The heat transfer chamber 102 has a top (not shown) sealed by a plurality of recovery plenums that can be combined with a common exhaust device. The non - reactive fluidizing gas can be cooled as needed (e.g., when exiting the heat transfer chamber 102) to meet the requirements of blower operation (e.g., recycling nitrogen, etc.), and, if desired, the heat input in the heating zone 102a can be reduced using an energy - saving method such as gas - to - gas exchange with the supply gas injection nozzle 126a. Before the blower, entrained solids can pass through a cyclone and return to the heat transfer chamber 102. In a preferred embodiment, the fluidization behavior of the heat transfer chamber can be in the bubbling regime (e.g., to reduce the amount of entrained solids exiting the system).

[0040] For the solid medium, a powder form of Geldart Group A, preferably brown aluminum oxide having a Sauter (or surface area - to - volume) mean particle size of 100 μm, is used. This material has good strength and sufficient abrasion resistance for the target empty - tower gas velocity range, e.g., having a minimum fluidization velocity of about 1.2 - 1.5 times. Each of the heating zones 102a - c may have several baffles (e.g., to reduce cross - mixing of the solids). The bed level is maintained within each heating zone such that the tube bundle of the reaction tubes 106 is fully immersed when fluidized.

[0041] The temperature of the solid within each zone (heating zones 102a - c) can be controlled by varying the power input through an electric heater positioned on the wall of the heat transfer chamber 102 (see Figure 4) and / or by varying the flow rate of the fluidizing gas. The volumetric flow rate of nitrogen is varied within each zone to maintain a bubbling fluidized bed. However, for example, in the case of a Geldart Group A solid, the minimum fluidization velocity decreases with increasing temperature, so at lower temperatures, more gas is required. Varying the temperature of the fluidized solid over the entire length of the reactor enables enhancement of the tube size, especially in zones where heat generation begins to exceed the internal heat transfer coefficient at the boundary of the process gas liner. In contrast, due to the solids being well - mixed, a vertical arrangement of reaction tubes with a single fluidized bed has no multiple heating zones and cannot support changes in the heat removal rate (e.g., supplying less heat to the exothermic part and / or cooling a specific zone), which reduces the yield of vinyltrichlorosilane in the converted silane when the temperature becomes too high.

[0042] To accommodate thermal expansion, numerous methods can be employed. The expansion difference of the reactor can be approximately 2 inches at the maximum temperature in the case of a large - scale commercial reactor process. Roller supports (such as roller supports 210 and 226) can be employed to accommodate thermal expansion. Additional devices can include steel / graphite slide plates or ceramic (SiC) slip bearings. Optionally, a telescopic bellows (not shown) can be incorporated into the steam outlet 132.

[0043] The cooling transition unit 110 can also be a fluidized bed in a manner similar to that described above for the heat transfer chamber 102. The floating head 108 is disposed within this separate fluidization zone (e.g., the cooling transition unit 110).

[0044] The following examples are for illustrative purposes only and are not intended to limit the scope of the appended claims.

Example

[0045] Example 1 To attempt the thermal condensation of trichlorosilane and vinyl chloride, a through-flow reaction tube (316 / 316L stainless steel) was assembled that included an internal liner made of isomolded graphite coated with SiC and an internal multi-element type K thermocouple assembly with a protective Hexaloy® SiC sheath. To ensure seals around the internal liner and the thermocouple sheath, a sealing gland assembly was used to isolate the reactants from the stainless steel reaction tube and the thermocouple assembly. The thermocouple assembly was arranged coaxially with the reaction tube, and the reaction tube was immersed inside an electrically heated fluidized sand bath system.

[0046] Nitrogen was used as the fluidizing gas for the sand bath, and the variation in the feed pressure of nitrogen was monitored to ensure uniform fluidization. The temperature of the sand bath was specified and controlled to the temperatures listed in Figure 6 (e.g., over the range of 520 °C to 595 °C). The pressure of the reactor was controlled using a pressure control valve with feedback control positioned downstream of the reactor effluent. After the effluent gas was cooled and the condensable chlorosilane liquid was removed from the vapor, the product was recovered. The internal temperature profile (over three positions) of the tube was monitored using a data acquisition system, and the temperature and pressure of the system were normalized before starting the campaign.

[0047] Under conditions of fixed reactor pressure and fixed sand bath temperature, vapors of vinyl chloride and trichlorosilane with a fixed flow of argon were injected into the reaction tube. Both the reactor inlet and effluent were monitored in real time using a gas chromatograph (equipped with a thermal conductivity detector) and a mass spectrometer. The recovered liquid was also analyzed during campaigns of fixed compositions. Chemical substances detected in the reactor effluent included argon, hydrogen chloride, vinyl chloride, trichlorosilane, vinyltrichlorosilane, silicon tetrachloride, ethyltrichlorosilane, methyltrichlorosilane, vinyldichlorosilane, benzene, 1,1,3-trichloro-1-silylcyclo-3-pentene, phenyltrichlorosilane, and 1,2-bis(trichlorosilyl)ethane (the abundance of each species varied with temperature).

[0048] Figure 6 is a yield plot for experiments involving the thermal condensation of trichlorosilane and vinyl chloride, showing the molar yield based on a vapor sampling technique as a function of trichlorosilane conversion. During these experiments, the pressure was fixed and maintained at 26 psia (176.9 kPa). Figure 6 shows the peak yield.

[0049] Example 2 Using the apparatus described in Example 1, vapors of vinyl chloride and dimethylchlorosilane with a fixed flow of argon were injected under conditions of fixed reactor pressure and fixed sand bath temperature. Both the reactor inlet and effluent were monitored in real time using a gas chromatograph (equipped with a thermal conductivity detector) and a mass spectrometer. The recovered liquid was also analyzed during campaigns of fixed compositions. Chemical substances detected in the reactor effluent included argon, hydrogen chloride, vinyl chloride, dimethylchlorosilane, dimethylvinylchlorosilane, dimethyldichlorosilane, ethyldimethylchlorosilane, methylvinyldichlorosilane, allyldimethylsilyl chloride, phenyldimethylchlorosilane, and 1,2-bis(dimethylchlorosilyl)ethane (the abundance of each species varied with temperature).

[0050] During the experiment, the residence time was kept constant (14 seconds), and the reactor pressure was fixed and maintained at 26 psia (176.9 kPa). This reaction is slower than the reaction of trichlorosilane and vinyl chloride. Table 1 below shows that the yield of dimethylvinylchlorosilane exceeds the maximum near 580 °C and has significant corrosion in the yield of the desired product at 595 °C.

Table 1

[0051] It is understood that the present disclosure is not limited to the embodiments specifically disclosed and illustrated herein. Various modifications of the present invention will become apparent to those skilled in the art. Such changes and modifications can be made without departing from the scope of the appended claims. Further, each of the specifically recited ranges includes all combinations and subcombinations of the ranges, as well as the specific numbers included therein.

Claims

1. A thermal condensation reactor, comprising a heat transfer chamber, said heat transfer chamber being a fluidized bed having a fluidizing gas flow in a first direction, said heat transfer chamber comprising a plurality of heating zones maintained at different temperatures; and a plurality of reaction tubes disposed in the heat transfer chamber in a second direction perpendicular to the fluidizing gas flow, each of said plurality of reaction tubes having a reaction gas flow passing through said plurality of heating zones.

2. The thermal condensation reactor according to claim 1, wherein the fluidizing gas flow is vertical and the reaction gas flow is horizontal.

3. The thermal condensation reactor according to claim 1, further comprising a port for introducing shroud gas, said shroud gas flowing through a part of each of said plurality of reaction tubes.

4. The thermal condensation reactor according to claim 3, wherein the reaction gas is a mixture of vinyl chloride and trichlorosilane, and the shroud gas is silicon tetrachloride.

5. The thermal condensation reactor according to claim 1, wherein each of said plurality of reaction tubes is associated with a sealing gland integrated with an internal liner comprising any one of graphite, carbon fiber / carbon composite, isomolded graphite coated with silicon carbide, or silicon carbide.

6. The thermal condensation reactor according to claim 1, further comprising a bonnet for covering the gas flow inlet of said plurality of reaction tubes.

7. The thermal condensation reactor according to claim 1, further comprising a floating head for covering the gas flow outlet of said plurality of reaction tubes, said floating head being movable in said second direction.

8. The thermal condensation reactor according to claim 7, further comprising a cooling transfer unit including said floating head, said cooling transfer unit also being a fluidized bed.

9. The thermal condensation reactor according to claim 1, further comprising one or more roller supports associated with said heat transfer chamber for accommodating thermal expansion.

10. The thermal condensation reactor according to claim 1, further comprising one or more baffles disposed in said heat transfer chamber.

11. A process for producing an alkenyl-functionalized halosilane, comprising: pre-mixing an alkenyl halide and a hydride-functionalized halosilane to produce a reaction gas; and introducing said reaction gas into a plurality of reaction tubes horizontally disposed in a fluidized bed. Passing the reaction gas through a plurality of heating zones in the fluidized bed, wherein the plurality of heating zones are maintained at different temperatures. The process includes this passing step.

12. The process according to claim 11, further comprising diluting the reaction gas with a shroud gas containing the halogenated product of the hydride-functional halosilane and hydrogen halide.

13. The process according to claim 11 or 12, wherein the halogenated alkenyl is vinyl chloride.

14. wherein said hydridofunctional halosilane has the chemical formula R ｗ H ｘ SiX （４－ｗ－ｘ） where w is from 0 to 2, x is from 1 to 3, the quantity (w + x) is from 1 to 3, each R is an independently selected monovalent hydrocarbon group of 1 to 18 carbon atoms without aliphatic unsaturation, and each X is an independently selected halogen atom, the process according to claim 11 or 12.

15. The process according to claim 14, wherein the hydride-functional halosilane is trichlorosilane.

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