A dehydration method in accordance with an embodiment of the present invention includes: a first dehydration step of bringing hydrogen chloride gas (21) and concentrated sulfuric acid (13A) into contact with each other; and a second dehydration step of bringing hydrogen chloride gas (21A) that has been obtained through the first dehydration step into contact with concentrated sulfuric acid (13B). A concentration of the concentrated sulfuric acid used in the second dehydration step is higher than a concentration of the concentrated sulfuric acid used in the first dehydration step.

To prevent solidified aluminum chloride from adhering to and accumulating on a pipe and also prevent stress-corrosion cracking in the pipe, a method for producing trichlorosilane includes a cooling step of cooling a discharge gas that is discharged from a fluidized-bed reactor and that contains the trichlorosilane, the cooling step involving causing a fluid to flow through a space (4) inside a side wall (3) of a pipe (10), the pipe being a pipe for discharging the discharge gas from the fluidized-bed reactor, in such a manner that the side wall (3) has a surface (1a) having a temperature of not lower than 110° C.

A process for preparing a product including a monohydrogentrihalosilane is disclosed. The process includes the steps of: 1) initially charging a reactor with a contact mass including both fresh silicon and recycled contact mass, where the recycled contact mass is obtained from during or after a production phase of an inorganic Direct Process reaction for production of a monohydrogentrihalosilane; and thereafter 2) feeding to the reactor a hydrogen halide and additional fresh silicon, thereby forming the product.

An object of the present invention is to prevent stress-corrosion cracking of a header (40) of a reactor. A reactor for producing trichlorosilane by causing metal silicon powder and a hydrogen chloride gas to react with each other includes a cooler (70), the cooler including a plurality of heat transfer medium pipes (30) and a header (40), the plurality of heat transfer medium pipes being provided in a fluid bed (60) inside the reactor, the header being provided in a freeboard section (50) inside the reactor, the header being comprised of a corrosion-resistant material.

An apparatus for producing trichlorosilane in which metallurgical grade silicon powder supplied to a reactor is reacted with hydrogen chloride gas while being fluidized by the hydrogen chloride gas, thereby discharging trichlorosilane generated by the reaction from the reactor, includes: a plurality of gas flow controlling members which are installed along a vertical direction in an annular shape R from an inner peripheral wall of the reactor in an internal space of the reactor; and a heat transfer tube which is installed along the vertical direction in the annular space R and through which a heating medium passes.

The present invention relates to internals useful for minimizing bubble size in a bubbling fluidized bed reactor. One use for the invention is in an apparatus and method for producing trichlorosilane in which metallurgical grade silicon is reacted with hydrogen chloride gas and while being fluidized by the hydrogen chloride gas, thereby producing trichlorosilane.

Chlorosilanes and methods of producing chlorosilanes. The process for producing chlorosilanes includes the step of selecting a chlorosilane having a general formulae (1) H.sub.nSiCl.sub.4-n and (2) H.sub.mCl.sub.6-mSi.sub.2 wherein n is 0 to 3 and m is from 0 to 4. The chlorosilane selected is then placed within a fluidized bed reactor. A hydrogen chloride-containing reaction gas is reacted with a particulate contact mass containing silicon at temperatures of 280° C. to 400° C. Where the operating granulation, understood as meaning the granulation or granulation mixture introduced into the fluidized bed reactor, contains at least 1% by mass of silicon-containing particles S described by a structural parameter S and wherein S has a value of at least 0 and is calculated as follows

[00001]$S=\left({\phi }_s-0.70\right).Math.\frac{{\rho }_{SD}}{{\rho }_F}$

Wherein φ.sub.S is symmetry-weighted sphericity factor, ρ.sub.SD is poured density [g/cm.sup.3], and ρ.sub.F is average particle solids density [g/cm.sup.3].

In the hydrochlorination reaction, silicon tetrachloride (STC), metallurgical silicon, and hydrogen are converted to trichlorosilane (TCS) at about 540° C. Previously, a pilot-scale reactor was used to study the yield of TCS produced by the hydrochlorination reaction. The yield observed by experimentation compared favorably with a scalable mathematical model developed to predict the rate of TCS conversion. The model predicted that 90% of the final amount of TCS produced was achieved after the reactant gas traveled a quarter of the vertical distance in the reaction section of the reactor. The pilot-scale reactor was shortened to verify the model predictions. In addition, some catalytic effects on the reaction were studied.

To provide a fluidized-bed reaction vessel and a trichlorosilane production method each of which can reduce corrosion and wear of a reaction container inner wall, a fluidized-bed reaction vessel causes metallurgical grade silicon powder and hydrogen chloride gas to react with each other for production of trichlorosilane. The fluidized-bed reaction vessel includes a plurality of ejection nozzles (20) standing on a distributor plate (11) as a bottom surface of a container body. The ejection nozzles (20) each have a gas ejection opening (22a) configured to allow hydrogen chloride gas to be ejected sideways. The plurality of ejection nozzles (20) include a first ejection nozzle (20a) adjacent to an outer wall (10a) of the container body, the first ejection nozzle (20a) having a gas ejection opening (22a) in such a pattern as to prevent hydrogen chloride gas from being ejected toward the outer wall (10a).

In the hydrochlorination reaction, silicon tetrachloride (STC), metallurgical silicon, and hydrogen are converted to trichlorosilane (TCS) at about 540° C. Previously, a pilot-scale reactor was used to study the yield of TCS produced by the hydrochlorination reaction. The yield observed by experimentation compared favorably with a scalable mathematical model developed to predict the rate of TCS conversion. The model predicted that 90% of the final amount of TCS produced was achieved after the reactant gas traveled a quarter of the vertical distance in the reaction section of the reactor. The pilot-scale reactor was shortened to verify the model predictions. In addition, some catalytic effects on the reaction were studied.