CN109694077B - Device and method for converting silicon tetrachloride into trichlorosilane - Google Patents
Device and method for converting silicon tetrachloride into trichlorosilane Download PDFInfo
- Publication number
- CN109694077B CN109694077B CN201711002496.6A CN201711002496A CN109694077B CN 109694077 B CN109694077 B CN 109694077B CN 201711002496 A CN201711002496 A CN 201711002496A CN 109694077 B CN109694077 B CN 109694077B
- Authority
- CN
- China
- Prior art keywords
- fluidized bed
- bed reactor
- silicon tetrachloride
- trichlorosilane
- hydrogen
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- 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
- C01B33/10763—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 from silicon
-
- 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
Abstract
The invention discloses a device and a method for converting silicon tetrachloride into trichlorosilane, wherein the device comprises the following components: the first fluidized bed reactor is used for introducing silicon tetrachloride, hydrogen and silicon to perform a cold hydrogenation reaction to generate trichlorosilane; the second fluidized bed reactor is connected with the first fluidized bed reactor, the material in the first fluidized bed reactor flows into the second fluidized bed reactor, the section of the first fluidized bed reactor vertical to the material flowing direction in the first fluidized bed reactor is a first section, the section of the second fluidized bed reactor vertical to the material flowing direction in the second fluidized bed reactor is a second section, the second section is larger than the first section, and a first opening is arranged on a pipeline between the outlet of the first fluidized bed reactor and the inlet of the second fluidized bed reactor. The device can ensure that the second fluidized bed reactor maintains the similar or same fluidization state as the first fluidized bed reactor, and increases the processing amount of silicon tetrachloride and the yield of silicon trichloride in unit time of the whole device.
Description
Technical Field
The invention belongs to the technical field of polysilicon production, and particularly relates to a device and a method for converting silicon tetrachloride into trichlorosilane.
Background
Whether the trichlorosilane reduction method is adopted in the production of polysilicon or the polysilicon is producedBy the silane decomposition method, a large amount of silicon tetrachloride is generated. As a byproduct or an intermediate product in the production of polycrystalline silicon, the recovery and the utilization of silicon tetrachloride not only can reduce the environmental pollution, but also can form a closed loop in the production of polycrystalline silicon, thereby greatly reducing the production cost. At present, the silicon tetrachloride is basically processed into trichlorosilane by a dechlorination and hydrogenation method. Among various dechlorination and hydrogenation technologies, the method for generating trichlorosilane by carrying out cold hydrogenation reaction on silicon tetrachloride, hydrogen and silicon powder has the advantages of low energy consumption, relatively high conversion rate and the like, and is an optimal technology for recycling and utilizing silicon tetrachloride. The chemical reaction of cold hydrogenation is as follows:
the tail gas after the cold hydrogenation reaction contains trichlorosilane, unreacted silicon tetrachloride and hydrogen, by-products of hydrogen chloride and a small amount of dichlorosilane.
In a fixed bed in a laboratory, the conversion per pass of silicon tetrachloride in the cold hydrogenation reaction is closer to the theoretical conversion, and can reach 35-40%. In the fluidized bed in actual production, the per-pass conversion rate of the silicon tetrachloride is usually below 25%, the deviation between the actual conversion rate and a theoretical value in production is large, and the hydrogenation cost of the silicon tetrachloride is improved to a great extent. The root cause of low silicon tetrachloride conversion rate in the cold hydrogenation reaction of the fluidized bed method in the actual production is that the reaction residence time in the fluidized bed is insufficient, and the silicon powder particles can not be ideally fluidized. The cold hydrogenation reactors cannot be scaled up indefinitely, limited by the equipment fabrication, and therefore the existing direction of improvement has mainly focused on designing advanced reactor internals to optimize fluidization regimes, designing reactors in series to increase reaction residence time. These reactors have an effect of improving the fluidization state of the silicon powder, but when in use, on one hand, the shutdown maintenance is difficult, the discharge of the waste silicon powder is not facilitated, and on the other hand, the problem of insufficient reaction residence time cannot be fundamentally solved. Under the conditions that the cold hydrogenation reactor is expensive, and the silicon tetrachloride conversion rate of the cold hydrogenation reactor is simply increased without little change, the series connection of a plurality of cold hydrogenation reactors cannot obtain good economic benefit. Patent CN201720046 provides a reactor with multi-layer porous fluidization plates, patent CN201801385 provides a fluidized bed reactor with sieve plates, patent CN102001668 provides a fluidized bed reactor with a microcirculation distribution structure, and these reactors have the function of improving the fluidization state of silicon powder, but when in use, on one hand, the shutdown maintenance is difficult, the discharge of waste silicon powder is not facilitated, and on the other hand, the problem of insufficient reaction residence time cannot be fundamentally solved. Patent CN103101913 provides a method of multiple reactors in series, which increases the reaction residence time, but still has the following disadvantages: 1) in a pipeline between the upper-stage reactor and the lower-stage reactor, the trichlorosilane is easy to generate the reverse reaction of the cold hydrogenation reaction under the high-temperature condition and is changed into silicon tetrachloride again; 2) the conversion rate of the silicon tetrachloride in the cold hydrogenation reaction changes logarithmically along with the change of the reaction residence time, namely when the reaction residence time is taken as an abscissa and the conversion rate of the silicon tetrachloride is taken as an ordinate, the reaction residence time is small, and the conversion rate of the silicon tetrachloride is increased rapidly along with the increase of the reaction residence time; when the reaction residence time value is large, the silicon tetrachloride conversion rate is increased slowly along with the increase of the reaction residence time value and gradually approaches an equilibrium value, and under the conditions that the cold hydrogenation reactor is expensive and the change range of the silicon tetrachloride conversion rate of the reactor is small by simply increasing, a plurality of reactors connected in series cannot obtain good economic benefit.
Disclosure of Invention
The invention aims to solve the technical problem that in order to overcome the defects in the prior art, the invention provides the device and the method for converting the silicon tetrachloride into the trichlorosilane, and the treatment capacity of the second fluidized bed reactor in unit time is increased, so that the treatment capacity of the device for converting the silicon tetrachloride into the trichlorosilane in unit time and the yield of the trichlorosilane are integrally improved.
The technical scheme adopted for solving the technical problem of the invention is to provide a device for converting silicon tetrachloride into trichlorosilane, which comprises the following components:
the first fluidized bed reactor is used for introducing silicon tetrachloride, hydrogen and silicon to perform a cold hydrogenation reaction to generate trichlorosilane;
the second fluidized bed reactor is connected with the first fluidized bed reactor, materials in the first fluidized bed reactor flow into the second fluidized bed reactor, the section of the first fluidized bed reactor, which is vertical to the material flow direction in the first fluidized bed reactor, is a first section, the section of the second fluidized bed reactor, which is vertical to the material flow direction in the second fluidized bed reactor, is a second section, the second section is larger than the first section, a first opening is arranged on a pipeline between the outlet of the first fluidized bed reactor and the inlet of the second fluidized bed reactor, the first opening is used for supplementing and introducing silicon tetrachloride or silicon tetrachloride and hydrogen into the second fluidized bed reactor, and the silicon tetrachloride, the hydrogen and the silicon in the second fluidized bed reactor are subjected to cold hydrogenation reaction to generate trichlorosilane.
Preferably, the first fluidized bed reactor comprises a first inlet and a second inlet, the first inlet is used for introducing a gas raw material into the first fluidized bed reactor, the second inlet is used for introducing a solid raw material into the fluidized bed reactor, and the device for converting silicon tetrachloride into trichlorosilane further comprises:
a first preheater provided on the conduit leading to the first inlet for preheating a gaseous feed to be fed into the first fluidized bed reactor through the first inlet.
Preferably, the device for converting silicon tetrachloride into trichlorosilane further comprises:
the second preheater is arranged on the branch pipeline leading to the first opening and is used for preheating silicon tetrachloride or silicon tetrachloride and hydrogen which are to enter the second fluidized bed reactor through the first opening; or the second preheater is arranged on a pipeline between the first opening and the inlet of the second fluidized bed reactor, and is used for preheating silicon tetrachloride or silicon tetrachloride and hydrogen which are to enter the second fluidized bed reactor through the first opening and materials flowing out of the outlet of the first fluidized bed reactor.
Preferably, the first opening is provided at any one of the first half sections of the conduit between the outlet of the first fluidized bed reactor and the inlet of the second fluidized bed reactor.
Preferably, the volume ratio of the second fluidized bed reactor to the first fluidized bed reactor is (1.1025-2.25): 1.
preferably, the area ratio of the second cross section to the first cross section is (1.1025-2.25): 1.
the invention also provides a method for converting silicon tetrachloride into trichlorosilane, which uses the device and comprises the following steps:
(1) introducing silicon tetrachloride, hydrogen and silicon into the first fluidized bed reactor, and carrying out a cold hydrogenation reaction on the silicon tetrachloride, the hydrogen and the silicon in the first fluidized bed reactor to generate trichlorosilane;
(2) and the material in the first fluidized bed reactor flows into a second fluidized bed reactor, silicon tetrachloride or silicon tetrachloride and hydrogen are supplemented into the second fluidized bed reactor through the first opening, and the silicon tetrachloride, the hydrogen and the silicon are subjected to a cold hydrogenation reaction in the second fluidized bed reactor to generate trichlorosilane.
Preferably, the device for converting silicon tetrachloride into trichlorosilane is used, and a step (i) of preheating silicon tetrachloride or silicon tetrachloride and hydrogen to be fed into a second fluidized bed reactor through a first opening by a second preheater is further included between the step (1) and the step (2).
The cold hydrogenation reaction is a slightly exothermic reaction, but since the first fluidized bed reactor transfers heat to the outside and the raw material silicon is added therein, in the case of continuous or semi-continuous addition of silicon, the temperature at the outlet of the first fluidized bed reactor is generally lower than the temperature inside the first fluidized bed reactor. The second preheater arranged on the branch pipeline leading to the first opening preheats silicon tetrachloride or silicon tetrachloride and hydrogen which enter the second fluidized bed reactor through the first opening, and the preheated silicon tetrachloride or silicon tetrachloride and hydrogen can exchange heat with the material at the outlet of the first fluidized bed reactor, so that the temperature condition of cold hydrogenation reaction in the second fluidized bed reactor is favorably achieved.
Preferably, the preheating temperature in the step (i) is 20 to 100 ℃ higher than the temperature of the cold hydrogenation reaction in the first fluidized bed reactor.
Preferably, the above apparatus for converting silicon tetrachloride to trichlorosilane is used, and the step (1) is preceded by the step (j) of preheating silicon tetrachloride and hydrogen to be fed into the first fluidized bed reactor through the first inlet by a first preheater.
Preferably, the preheating temperature in the step (j) is 20 to 100 ℃ higher than the temperature of the cold hydrogenation reaction in the second fluidized bed reactor.
Preferably, the amount of the silicon tetrachloride substance additionally introduced into the second fluidized bed reactor through the first opening is 0.1 to 1 times of the amount of the silicon tetrachloride substance introduced into the first fluidized bed reactor.
Preferably, the molar ratio of the hydrogen to the silicon tetrachloride introduced into the first fluidized bed reactor is (1-3): 1.
preferably, the molar ratio of the hydrogen to the silicon tetrachloride which is additionally introduced into the second fluidized bed reactor through the first opening is (1-3): 1.
preferably, the material in the first fluidized bed reactor is in the same fluidization state as the material in the second fluidized bed reactor.
Preferably, the pressure in the first fluidized bed reactor and the second fluidized bed reactor is 1MPa to 5MPa, and the temperature is 450 ℃ to 600 ℃.
Preferably, the pressure in the first fluidized bed reactor and the second fluidized bed reactor is 2MPa to 3.5MPa, and the temperature is 500 ℃ to 580 ℃.
Silicon tetrachloride is additionally fed into a pipeline between the first fluidized bed reactor and the second fluidized bed reactor, so that on one hand, the concentration of the silicon tetrachloride in the material at the outlet of the first fluidized bed reactor can be increased, and the reverse reaction of the cold hydrogenation reaction of the trichlorosilane between the two reactors is inhibited to a certain extent; on the other hand, the concentration of the reactant silicon tetrachloride in the second fluidized bed reactor can be increased, so that the driving force of cold hydrogenation reaction in the second fluidized bed reactor is increased (the farther away from chemical balance, the larger the driving force is), the cold hydrogenation reaction is promoted to be rapidly carried out rightwards, the production capacity of the second fluidized bed reactor is improved, and finally the conversion amount of the silicon tetrachloride of the device for converting the silicon tetrachloride into the trichlorosilane, the treatment amount of the silicon tetrachloride in unit time and the yield of the trichlorosilane are increased.
In the invention, because the silicon tetrachloride is additionally introduced into the pipeline between the first fluidized bed reactor and the second fluidized bed reactor, and the second section of the second fluidized bed reactor is larger than the first section of the first fluidized bed reactor, the second fluidized bed reactor can maintain the fluidized state similar to or the same as that of the first fluidized bed reactor, and the treatment capacity of the silicon tetrachloride of the second fluidized bed reactor in unit time is increased, so that the treatment capacity of the silicon tetrachloride of the device for converting the silicon tetrachloride into the trichlorosilane in unit time and the yield of the trichlorosilane are integrally improved. In addition, by utilizing the technical scheme of the invention, the existing single fluidized bed reactor can be conveniently upgraded, and another fluidized bed reactor with a larger section is added behind the single reactor, so that the yield of trichlorosilane in unit time of the device in the prior art can be obviously increased, and obvious economic benefit can be obtained.
Drawings
FIG. 1 is a schematic structural diagram of a device for converting silicon tetrachloride into trichlorosilane in example 2 of the present invention;
fig. 2 is a schematic structural diagram of a device for converting silicon tetrachloride to trichlorosilane in example 5 of the present invention.
In the figure: 1-a first fluidized bed reactor; 2-a first inlet; 3-a second inlet; 4-the outlet of the first fluidized bed reactor; 5-a first preheater; 6-a second fluidized bed reactor; 7-a third inlet; 8-a fourth inlet; 9-outlet of the second fluidized bed reactor; 10-a second preheater; 11-first opening.
Detailed Description
In order to make the technical solutions of the present invention better understood, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
Example 1
The embodiment provides a device for converting silicon tetrachloride into trichlorosilane, which comprises:
the first fluidized bed reactor is used for introducing silicon tetrachloride, hydrogen and silicon to perform a cold hydrogenation reaction to generate trichlorosilane;
the second fluidized bed reactor is connected with the first fluidized bed reactor, materials in the first fluidized bed reactor flow into the second fluidized bed reactor, the section of the first fluidized bed reactor, which is vertical to the material flow direction in the first fluidized bed reactor, is a first section, the section of the second fluidized bed reactor, which is vertical to the material flow direction in the second fluidized bed reactor, is a second section, the second section is larger than the first section, a first opening is arranged on a pipeline between the outlet of the first fluidized bed reactor and the inlet of the second fluidized bed reactor, the first opening is used for supplementing and introducing silicon tetrachloride or silicon tetrachloride and hydrogen into the second fluidized bed reactor, and the silicon tetrachloride, the hydrogen and the silicon in the second fluidized bed reactor are subjected to cold hydrogenation reaction to generate trichlorosilane.
The embodiment also provides a method for converting silicon tetrachloride into trichlorosilane by using the device, which comprises the following steps:
(1) introducing silicon tetrachloride, hydrogen and silicon into the first fluidized bed reactor, and carrying out a cold hydrogenation reaction on the silicon tetrachloride, the hydrogen and the silicon in the first fluidized bed reactor to generate trichlorosilane;
(2) and the material in the first fluidized bed reactor flows into a second fluidized bed reactor, silicon tetrachloride or silicon tetrachloride and hydrogen are supplemented into the second fluidized bed reactor through the first opening, and the silicon tetrachloride, the hydrogen and the silicon are subjected to a cold hydrogenation reaction in the second fluidized bed reactor to generate trichlorosilane.
Silicon tetrachloride is additionally introduced into a pipeline between the first fluidized bed reactor and the second fluidized bed reactor in the embodiment, so that on one hand, the concentration of the silicon tetrachloride in the material at the outlet of the first fluidized bed reactor can be increased, and the reverse reaction of the cold hydrogenation reaction of the trichlorosilane between the two reactors is inhibited to a certain extent; on the other hand, the concentration of the reactant silicon tetrachloride in the second fluidized bed reactor can be increased, so that the driving force of cold hydrogenation reaction in the second fluidized bed reactor is increased (the farther the chemical balance is, the larger the driving force is), the cold hydrogenation reaction is promoted to be carried out rightwards more quickly, the second fluidized bed reactor can maintain a fluidized state similar to or the same as that of the first fluidized bed reactor, the production capacity of the second fluidized bed reactor is improved, and finally the conversion amount of the silicon tetrachloride of a device for converting the silicon tetrachloride into the trichlorosilane, the treatment amount of the silicon tetrachloride in unit time and the yield of the trichlorosilane are increased.
Example 2
As shown in fig. 1, this embodiment provides a device for converting silicon tetrachloride to trichlorosilane, including:
first fluidized bed reactor 1, first fluidized bed reactor 1 includes first entry 2, second entry 3, first fluidized bed reactor export 4, let in gaseous raw materials silicon tetrachloride, or silicon tetrachloride and hydrogen in to first fluidized bed reactor 1 through first entry 2, it is specific, let in silicon tetrachloride and hydrogen through first entry 2 in this embodiment, let in solid raw materials silica flour in to first fluidized bed reactor 1 through second entry 3, silicon tetrachloride, hydrogen, silica flour take place cold hydrogenation reaction and generate trichlorosilane in first fluidized bed reactor 1.
A first preheater 5 is provided on the pipe leading to the first inlet 2 for preheating the gaseous raw material to be introduced into the first fluidized bed reactor 1 through the first inlet 2.
A second fluidized bed reactor 6 connected with the first fluidized bed reactor 1, the second fluidized bed reactor 6 comprises a third inlet 7, a fourth inlet 8 and a second fluidized bed reactor outlet 9, the third inlet 7 is connected with the first fluidized bed reactor outlet 4, the material in the first fluidized bed reactor 1 flows into the second fluidized bed reactor 6, the section of the first fluidized bed reactor 1 vertical to the material flow direction in the first fluidized bed reactor 1 is a first section, the section of the second fluidized bed reactor 6 vertical to the material flow direction in the second fluidized bed reactor 6 is a second section, the second section is larger than the first section, the solid raw material silicon powder is introduced into the second fluidized bed reactor 6 through the fourth inlet 8, a first opening 11 is arranged on a pipeline between the first fluidized bed reactor outlet 4 and the second fluidized bed reactor 6 inlet, the first opening 11 is used for supplementing and introducing silicon tetrachloride or silicon tetrachloride and hydrogen into the second fluidized bed reactor 6, the silicon tetrachloride, the hydrogen and the silicon powder in the second fluidized bed reactor 6 are subjected to a cold hydrogenation reaction to generate trichlorosilane, and tail gas is discharged through an outlet 9 of the second fluidized bed reactor.
And the second preheater 10 is arranged on a branch pipeline leading to the first opening 11 and is used for preheating silicon tetrachloride or silicon tetrachloride and hydrogen which are to enter the second fluidized bed reactor 6 through the first opening 11.
In the present embodiment, the first opening 11 is provided at any one of the first half sections of the pipe between the outlet of the first fluidized bed reactor 1 and the inlet of the second fluidized bed reactor 6. Specifically, in the present embodiment, the first opening 11 is disposed at the position of the outlet 4 of the first fluidized bed reactor. Therefore, the reverse reaction of the cold hydrogenation reaction of the trichlorosilane in the material at the outlet of the first fluidized bed reactor 1 can be prevented by increasing the amount of the silicon tetrachloride at the outlet 4 of the first fluidized bed reactor.
In this embodiment, the cross section of the first fluidized bed reactor 1 perpendicular to the flow direction of the material in the first fluidized bed reactor 1 is a first cross section, the cross section of the second fluidized bed reactor 6 perpendicular to the flow direction of the material in the second fluidized bed reactor 6 is a second cross section, and the area ratio of the second cross section to the first cross section is 1.266: 1. specifically, the first cross section in this embodiment is a circle, the second cross section is a circle, and the ratio of the diameter of the first cross section to the diameter of the second cross section is 1.125: 1.
The embodiment also provides a method for converting silicon tetrachloride into trichlorosilane by using the device, which comprises the following steps:
(1) the gaseous raw materials silicon tetrachloride and hydrogen to be fed into the first fluidized bed reactor 1 through the first inlet 2 are preheated by a first preheater 5 at a preheating temperature of 600 ℃.
(2) Solid raw material silicon powder is added into a first fluidized bed reactor 1 through a second inlet 3, the temperature of the added raw material silicon powder is lower than the temperature of cold hydrogenation reaction, preheated silicon tetrachloride and hydrogen enter the first fluidized bed reactor 1 through a first inlet 2, heat is transferred to the solid raw material silicon powder, and the molar ratio of the hydrogen to the silicon tetrachloride introduced into the first fluidized bed reactor 1 is 2:1, the feeding amount of hydrogen and silicon tetrachloride entering through the first inlet 2 is 80 tons/hour. The pressure in the first fluidized bed reactor 1 and the second fluidized bed reactor 6 is 2.5MPa, the temperature is 550 ℃, and silicon tetrachloride, hydrogen and silicon powder are subjected to cold hydrogenation reaction in the first fluidized bed reactor 1 to generate trichlorosilane.
(3) The silicon tetrachloride, or silicon tetrachloride and hydrogen, which is to enter the second fluidized bed reactor 6 through the first opening 11, is preheated by a second preheater 10 at a preheating temperature of 600 ℃.
(4) The material in the first fluidized bed reactor 1 flows into the second fluidized bed reactor 6, the total content of trichlorosilane in the material at the outlet of the first fluidized bed reactor 1 is 24.5 wt%, preheated silicon tetrachloride or silicon tetrachloride and hydrogen are supplemented and introduced into the second fluidized bed reactor 6 through the first opening 11, and the molar ratio of the fed hydrogen to the silicon tetrachloride in the second fluidized bed reactor 6 through the first opening 11 is 2:1, the feeding amount of the hydrogen and the silicon tetrachloride which are additionally introduced through the first opening 11 is 21.5 tons/hour, and after the mixed gas of the hydrogen and the silicon tetrachloride which are additionally introduced through the first opening 11 is mixed with the material at the outlet of the first fluidized bed reactor 1, the content of the trichlorosilane is reduced to 19.3 wt%. The amount of the substance of silicon tetrachloride which is additionally fed into the second fluidized bed reactor 6 through the first opening 11 is 0.27 times the amount of the substance of silicon tetrachloride which is fed into the first fluidized bed reactor 1. The material in the first fluidized bed reactor 1 is in the same fluidization state as in the second fluidized bed reactor 6. The pressure in the first fluidized bed reactor 1 and the second fluidized bed reactor 6 was 2.5MPa, and the temperature was 550 ℃. Silicon tetrachloride, hydrogen and silicon powder are subjected to a cold hydrogenation reaction in the second fluidized bed reactor 6 to generate trichlorosilane, tail gas is discharged through an outlet 9 of the second fluidized bed reactor, and the content of trichlorosilane in the tail gas is 29.2 wt%. Finally, the yield of the trichlorosilane in the device is 29.6 tons/hour.
The cold hydrogenation reaction is a slightly exothermic reaction, but since the first fluidized bed reactor 1 transfers heat to the outside and silicon powder below the reaction temperature is added therein, the temperature of the outlet 4 of the first fluidized bed reactor is generally lower than the temperature of the inside of the first fluidized bed reactor 1 in the case of continuous or semi-continuous addition of silicon powder. The second preheater 10 arranged on the branch pipeline leading to the first opening 11 preheats silicon tetrachloride or silicon tetrachloride and hydrogen which are to enter the second fluidized bed reactor 6 through the first opening 11, and the preheated silicon tetrachloride or silicon tetrachloride and hydrogen can exchange heat with the material at the outlet 4 of the first fluidized bed reactor, so that the temperature condition of cold hydrogenation reaction in the second fluidized bed reactor 6 is favorably achieved.
Silicon tetrachloride is additionally introduced into a pipeline between the first fluidized bed reactor 1 and the second fluidized bed reactor 6 in the embodiment, so that on one hand, the concentration of the silicon tetrachloride in the material at the outlet 4 of the first fluidized bed reactor can be increased, and thus the reverse reaction of the cold hydrogenation reaction of the trichlorosilane between the two reactors is inhibited to a certain extent; on the other hand, the concentration of the reactant silicon tetrachloride in the second fluidized bed reactor 6 can be increased, so that the driving force of the cold hydrogenation reaction in the second fluidized bed reactor 6 is increased (the farther the chemical balance is, the larger the driving force is), the cold hydrogenation reaction is promoted to be rapidly carried out rightward, the production capacity of the second fluidized bed reactor 6 is improved, and finally the conversion amount of the silicon tetrachloride of the device for converting the silicon tetrachloride into the trichlorosilane, the treatment amount of the silicon tetrachloride in unit time and the yield of the trichlorosilane are increased.
In the embodiment, because the pipeline between the first fluidized bed reactor 1 and the second fluidized bed reactor 6 is additionally filled with silicon tetrachloride, and the second cross section of the second fluidized bed reactor 6 is larger than the first cross section of the first fluidized bed reactor 1, the second fluidized bed reactor 6 can maintain the fluidized state similar to or the same as that of the first fluidized bed reactor 1, and the treatment amount of the silicon tetrachloride of the second fluidized bed reactor 6 per unit time is increased.
Comparative example 1
The comparative example provides a device for converting silicon tetrachloride into trichlorosilane, and the device comprises: the cross section of the two fluidized bed reactors is the same, wherein the cross section of the fluidized bed reactor refers to the cross section which is vertical to the material flowing direction in the fluidized bed reactors.
The embodiment provides a method for converting silicon tetrachloride into trichlorosilane by using the device, which comprises the following steps:
(1) and introducing solid raw material silicon powder into a third fluidized bed, wherein the feeding amount of the introduced gas raw materials of silicon tetrachloride and hydrogen is 80 tons/hour, the pressure in the third fluidized bed reactor is 2.5Mpa, the temperature is 550 ℃, the silicon tetrachloride, the hydrogen and the silicon are subjected to a cold hydrogenation reaction in the third fluidized bed reactor to generate trichlorosilane, and the molar ratio of the introduced silicon tetrachloride to the hydrogen is 2: 1.
(2) And the material in the third fluidized bed reactor flows into the fourth fluidized bed reactor, the pressure in the third fluidized bed reactor is 2.5Mpa, the temperature is 550 ℃, the cold hydrogenation reaction of the silicon tetrachloride, the hydrogen and the silicon in the fourth fluidized bed reactor is continuously carried out to generate the trichlorosilane, and the content of the trichlorosilane in the tail gas at the outlet of the fourth fluidized bed reactor is 30.8 wt%. Finally, the output of the trichlorosilane device is 24.6 tons/hour
Example 3
The embodiment provides a device for converting silicon tetrachloride into trichlorosilane, which is different from the device in embodiment 2 in that:
in this embodiment, the area ratio of the second cross section to the first cross section is 1.1025: 1.
in this embodiment the first opening is provided in the first half of the duct between the outlet of the first fluidized bed reactor and the inlet of the second fluidized bed reactor.
The embodiment provides a method for converting silicon tetrachloride into trichlorosilane by using the device, and the method is different from the method in the embodiment 2 in that:
in this example, the preheating temperature in step (1) was 680 ℃.
In the step (2), the molar ratio of the hydrogen and the silicon tetrachloride introduced into the first fluidized bed reactor is 1: 1; the pressure in the first fluidized bed reactor and the second fluidized bed reactor is 1MPa, and the temperature is 600 ℃.
In the step (3), the gas raw material to be added into the second fluidized bed reactor through the first opening is silicon tetrachloride, and the preheating temperature is 680 ℃.
In the step (4), the mass of the silicon tetrachloride substance which is supplemented and introduced into the second fluidized bed reactor through the first opening is 1 time of the mass of the silicon tetrachloride substance which is introduced into the first fluidized bed reactor; the molar ratio of the fed hydrogen to the silicon tetrachloride in the second fluidized bed reactor 6 is 1: 1, the pressure in the second fluidized bed reactor is 1MPa, and the temperature is 600 ℃.
Example 4
The embodiment provides a device for converting silicon tetrachloride into trichlorosilane, which is different from the device in embodiment 2 in that:
in this embodiment, the area ratio of the second cross section to the first cross section is 2.25: 1.
in this embodiment the first opening is arranged in one half of the conduit between the outlet of the first fluidized bed reactor and the inlet of the second fluidized bed reactor.
The embodiment provides a method for converting silicon tetrachloride into trichlorosilane by using the device, and the method is different from the method in the embodiment 2 in that:
in this example, the preheating temperature in step (1) was 550 ℃.
In the step (2), the molar ratio of the hydrogen and the silicon tetrachloride introduced into the first fluidized bed reactor is 3: 1; the pressure in the first fluidized bed reactor and the second fluidized bed reactor is 5MPa, and the temperature is 450 ℃.
The preheating temperature in step (3) was 550 ℃.
In the step (4), the molar ratio of the fed hydrogen to the silicon tetrachloride which is supplemented into the second fluidized bed reactor through the first opening is 3: 1; the mass of the silicon tetrachloride substance which is additionally introduced into the second fluidized bed reactor through the first opening is 0.1 time of the mass of the silicon tetrachloride substance which is introduced into the first fluidized bed reactor; the pressure in the second fluidized bed reactor was 5MPa and the temperature was 450 ℃.
Example 5
As shown in fig. 2, this embodiment provides an apparatus for converting silicon tetrachloride to trichlorosilane, which differs from the apparatus in embodiment 2 in that:
the second preheater 10 is disposed on the pipe between the first opening 11 and the inlet of the second fluidized bed reactor 6, and the second preheater 10 is used for preheating silicon tetrachloride or silicon tetrachloride and hydrogen gas to be introduced into the second fluidized bed reactor 6 through the first opening 11, and materials flowing out of the outlet 4 of the first fluidized bed reactor.
The embodiment provides a method for converting silicon tetrachloride into trichlorosilane by using the device, and the method is different from the method in the embodiment 2 in that:
in this example, the preheating temperature in step (1) was 520 ℃.
In the step (2), the molar ratio of the hydrogen to the silicon tetrachloride introduced into the first fluidized bed reactor 1 is 1.8: 1; the pressure in the first fluidized bed reactor 1 and the second fluidized bed reactor 6 was 3.5MPa, and the temperature was 500 ℃.
The preheating temperature in step (3) was 520 ℃.
In the step (4), the molar ratio of the hydrogen to the silicon tetrachloride which is additionally introduced into the second fluidized bed reactor 6 through the first opening 11 is 1.8: 1; the mass of the silicon tetrachloride substance which is additionally introduced into the second fluidized bed reactor 6 through the first opening 11 is 0.7 times of the mass of the silicon tetrachloride substance which is introduced into the first fluidized bed reactor 1; the pressure in the second fluidized bed reactor 6 was 3.5MPa and the temperature was 500 ℃.
It will be understood that the above embodiments are merely exemplary embodiments taken to illustrate the principles of the present invention, which is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and substance of the invention, and these modifications and improvements are also considered to be within the scope of the invention.
Claims (12)
1. A device for converting silicon tetrachloride into trichlorosilane is characterized by comprising:
the first fluidized bed reactor is used for introducing silicon tetrachloride, hydrogen and silicon to perform a cold hydrogenation reaction to generate trichlorosilane;
and a second fluidized bed reactor connected to the first fluidized bed reactor, wherein the material in the first fluidized bed reactor flows into the second fluidized bed reactor, the cross section of the first fluidized bed reactor perpendicular to the material flow direction in the first fluidized bed reactor is a first cross section, the cross section of the second fluidized bed reactor perpendicular to the material flow direction in the second fluidized bed reactor is a second cross section, the second cross section is larger than the first cross section, and the area ratio of the second cross section to the first cross section is (1.1025-2.25): 1, a first opening is arranged on a pipeline between an outlet of a first fluidized bed reactor and an inlet of a second fluidized bed reactor, the first opening is used for supplementing and introducing silicon tetrachloride or silicon tetrachloride and hydrogen into the second fluidized bed reactor, and the silicon tetrachloride, the hydrogen and the silicon are subjected to a cold hydrogenation reaction in the second fluidized bed reactor to generate trichlorosilane;
the device for converting the silicon tetrachloride into the trichlorosilane further comprises:
the second preheater is arranged on the branch pipeline leading to the first opening and is used for preheating silicon tetrachloride or silicon tetrachloride and hydrogen which are to enter the second fluidized bed reactor through the first opening; or the second preheater is arranged on a pipeline between the first opening and the inlet of the second fluidized bed reactor, and is used for preheating silicon tetrachloride or silicon tetrachloride and hydrogen which are to enter the second fluidized bed reactor through the first opening and materials flowing out of the outlet of the first fluidized bed reactor.
2. The apparatus for converting silicon tetrachloride to trichlorosilane according to claim 1, wherein the first fluidized bed reactor comprises a first inlet and a second inlet, a gas raw material is introduced into the first fluidized bed reactor through the first inlet, a solid raw material is introduced into the fluidized bed reactor through the second inlet, and the apparatus for converting silicon tetrachloride to trichlorosilane further comprises:
a first preheater provided on the conduit leading to the first inlet for preheating a gaseous feed to be fed into the first fluidized bed reactor through the first inlet.
3. The device for converting silicon tetrachloride to trichlorosilane according to any one of claims 1 to 2, wherein the first opening is arranged at any one of the first half sections of the pipeline between the outlet of the first fluidized bed reactor and the inlet of the second fluidized bed reactor.
4. A method for converting silicon tetrachloride into trichlorosilane is characterized in that the device of any one of claims 1-3 is used, and the method comprises the following steps:
(1) introducing silicon tetrachloride, hydrogen and silicon into the first fluidized bed reactor, and carrying out a cold hydrogenation reaction on the silicon tetrachloride, the hydrogen and the silicon in the first fluidized bed reactor to generate trichlorosilane;
(2) and the material in the first fluidized bed reactor flows into a second fluidized bed reactor, silicon tetrachloride or silicon tetrachloride and hydrogen are supplemented into the second fluidized bed reactor through the first opening, and the silicon tetrachloride, the hydrogen and the silicon are subjected to a cold hydrogenation reaction in the second fluidized bed reactor to generate trichlorosilane.
5. The method for converting silicon tetrachloride into trichlorosilane according to claim 4, wherein the device for converting silicon tetrachloride into trichlorosilane according to claim 1 is used, and the method between the step (1) and the step (2) further comprises the step of (i) preheating silicon tetrachloride or silicon tetrachloride and hydrogen which are about to enter a second fluidized bed reactor through a first opening by a second preheater.
6. The method for converting silicon tetrachloride into trichlorosilane according to claim 4, wherein the device for converting silicon tetrachloride into trichlorosilane according to claim 3 is used, and the preheating temperature in the step (i) is 20-100 ℃ higher than the temperature of the cold hydrogenation reaction in the second fluidized bed reactor.
7. The method for converting silicon tetrachloride into trichlorosilane according to claim 4, wherein the amount of the substance of silicon tetrachloride fed into the second fluidized bed reactor through the first opening is 0.1-1 times of the amount of the substance of silicon tetrachloride fed into the first fluidized bed reactor.
8. The method for converting silicon tetrachloride into trichlorosilane according to claim 4, wherein the molar ratio of the hydrogen to the silicon tetrachloride introduced into the first fluidized bed reactor is (1-3): 1.
9. the method for converting silicon tetrachloride into trichlorosilane according to claim 4, wherein the molar ratio of the additionally introduced hydrogen to the silicon tetrachloride in the second fluidized bed reactor through the first opening is (1-3): 1.
10. the method for converting silicon tetrachloride to trichlorosilane according to claim 4, wherein the material in the first fluidized bed reactor is in the same fluidized state as the material in the second fluidized bed reactor.
11. The method for converting silicon tetrachloride to trichlorosilane according to any one of claims 4 to 10, wherein the pressure in the first fluidized bed reactor and the second fluidized bed reactor is 1MPa to 5MPa, and the temperature is 450 ℃ to 600 ℃.
12. The method for converting silicon tetrachloride to trichlorosilane according to claim 11, wherein the pressure in the first fluidized bed reactor and the second fluidized bed reactor is 2MPa to 3.5MPa, and the temperature is 500 ℃ to 580 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711002496.6A CN109694077B (en) | 2017-10-24 | 2017-10-24 | Device and method for converting silicon tetrachloride into trichlorosilane |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711002496.6A CN109694077B (en) | 2017-10-24 | 2017-10-24 | Device and method for converting silicon tetrachloride into trichlorosilane |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109694077A CN109694077A (en) | 2019-04-30 |
| CN109694077B true CN109694077B (en) | 2021-04-06 |
Family
ID=66227826
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711002496.6A Active CN109694077B (en) | 2017-10-24 | 2017-10-24 | Device and method for converting silicon tetrachloride into trichlorosilane |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109694077B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116639699B (en) * | 2023-07-12 | 2024-02-02 | 江苏中圣高科技产业有限公司 | Production process and system for preparing trichlorosilane |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040047793A1 (en) * | 2000-12-14 | 2004-03-11 | Leslaw Mleczko | Method for producing trichlorosilane |
| US20040047794A1 (en) * | 2000-12-21 | 2004-03-11 | Matthias Pfaffelhuber | Fluidized bed reactor made of a nickel-chrome-molybdenum alloy for the synthesis of trichlorosilane |
| WO2007035108A1 (en) * | 2005-09-22 | 2007-03-29 | Elkem As | Method for production of trichlorosilane and silicon for use in the production of trichlorosilane |
| CN106395832A (en) * | 2015-08-03 | 2017-02-15 | 新特能源股份有限公司 | Silicon tetrachloride hydrogenation method |
-
2017
- 2017-10-24 CN CN201711002496.6A patent/CN109694077B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040047793A1 (en) * | 2000-12-14 | 2004-03-11 | Leslaw Mleczko | Method for producing trichlorosilane |
| US20040047794A1 (en) * | 2000-12-21 | 2004-03-11 | Matthias Pfaffelhuber | Fluidized bed reactor made of a nickel-chrome-molybdenum alloy for the synthesis of trichlorosilane |
| WO2007035108A1 (en) * | 2005-09-22 | 2007-03-29 | Elkem As | Method for production of trichlorosilane and silicon for use in the production of trichlorosilane |
| CN106395832A (en) * | 2015-08-03 | 2017-02-15 | 新特能源股份有限公司 | Silicon tetrachloride hydrogenation method |
Non-Patent Citations (1)
| Title |
|---|
| 三氯氢硅合成炉运行总结;柯曾等;《中国氯碱》;20120630(第6期);第28-29页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109694077A (en) | 2019-04-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101676203B (en) | Reactor for producing high purity granular silicon and method thereof | |
| CN102030329B (en) | Polycrystalline silicon producing device and process | |
| CN102502646B (en) | Equipment and method for preparing polysilicon by fast circulating fluidized bed-based chemical vapor deposition | |
| CN101696013A (en) | Method and device for producing polysilicon by using plasma assisting fluidized bed process | |
| CN111333029A (en) | Process for reforming and reducing iron and generating carbon nano tube by methane and carbon dioxide | |
| CN109694077B (en) | Device and method for converting silicon tetrachloride into trichlorosilane | |
| CN104556042B (en) | Method for preparing polysilicon based on improved Siemens and production of polysilicon equipment | |
| CN101531367B (en) | Process for producing silicane | |
| CN204057977U (en) | For the apparatus system of halogen silicon polymer cracking for halosilanes | |
| CN113387362A (en) | Improved method and device for synthesizing trichlorosilane by cold hydrogenation | |
| CN102557041A (en) | Method and device for continuous production of silicochloroform | |
| CN106986345B (en) | A method of producing silicochloroform | |
| CN103920428A (en) | Supercritical reaction device and technological process thereof | |
| CN201598181U (en) | Device for producing polycrystalline silicon by plasma auxiliary fluidized bed process | |
| CN207957782U (en) | It is a kind of without cycle ammonia synthesis system | |
| CN102745694B (en) | A kind of polysilicon production process and the production system for this technique | |
| CN215886877U (en) | Device for continuously producing alkyl orthosilicate from silicon powder | |
| CN202099066U (en) | Device for preparing silicane | |
| CN106276913B (en) | The method that polysilicon is manufactured after the recovered cycling and reutilization of improved Siemens polysilicon reducing furnace tail gas | |
| CN108069428B (en) | Device and process for treating polysilicon byproduct slag slurry | |
| CN107937038A (en) | A kind of polygenerations systeme of coal or gasification of biomass and methane cracking | |
| CN217120207U (en) | Storage type fluidized bed reactor for producing organic silicon monomer | |
| CN220684694U (en) | Polysilicon cold hydrogenation process system | |
| CN115215344B (en) | Preparation method and preparation device of trichlorosilane | |
| CN217895154U (en) | Trichlorosilane cold hydrogenation production system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Application publication date: 20190430 Assignee: Xinte silicon based new materials Co.,Ltd. Assignor: XINTE ENERGY Co.,Ltd. Contract record no.: X2022990000325 Denomination of invention: A device and method for converting silicon tetrachloride into trichlorosilane Granted publication date: 20210406 License type: Common License Record date: 20220627 Application publication date: 20190430 Assignee: Inner Mongolia Xinte silicon material Co.,Ltd. Assignor: XINTE ENERGY Co.,Ltd. Contract record no.: X2022990000326 Denomination of invention: A device and method for converting silicon tetrachloride into trichlorosilane Granted publication date: 20210406 License type: Common License Record date: 20220627 |
|
| EE01 | Entry into force of recordation of patent licensing contract |