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US 2013/0095026 A1Published application
Closed loop process for preparing trichlorosilane from metallurgical silicon
AssigneeEvonik Degussa GmbH
InventorsYuecel Oenal, Rainer Malzkorn, Ingo Pauli, Ingrid Lunt-Rieg, Guido Stochniol
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Abstract
The present invention relates to a multistage process for preparing trichlorosilane and silicon tetrachloride from metallurgical silicon, in which trichlorosilane and silicon tetrachloride are prepared from metallurgical silicon in a first step, and the silicon tetrachloride is processed further to the trichlorosilane end product in a second step. The present invention further relates to a plant in which such processes can be performed in an integrated manner.
Claims20
A process for preparing trichlorosilane, the process comprising:
- passing a first reactant stream comprising silicon tetrachloride, and a second reactant stream comprising hydrogen into a hydrodechlorination reactor,
- heating the hydrodechlorination reactor, thereby shifting a thermodynamic equilibrium position in a direction of products, thereby obtaining a product stream comprising silicon tetrachloride, trichlorosilane, hydrogen, and HCl
- cooling the product stream with a heat exchanger, and
- conducting the first reactant stream, the second reactant stream, or both through the heat exchanger, thereby preheating the first reactant stream, the second reactant stream, or both.
1 more element
A plant, comprising:
- a hydrodechlorination reactor in a heating chamber or a combustion chamber, optionally comprising a reactor tube in a combustion chamber;
- a first line configured to conduct a first gas comprising silicon tetrachloride and a second line configured to conduct a second gas comprising hydrogen, each leading into the hydrodechlorination reactor or the reactor tube, optionally in a combined line configured to conduct the first and second gases;
- a product gas line conducted out of the hydrodechlorination reactor, for the product gas line configured to conduct a trichlorosilane-containing and HCl-containing product gas;
- a heat exchanger through which the product gas line and the first line, the second line, or both are conducted, enabling heat transfer from the product gas line into the first line, the second line, or both, the heat exchanger optionally comprising a heat exchanger element comprising a ceramic material;
- optionally a plant component configured to remove silicon tetrachloride, trichlorosilane, hydrogen, HCl, or a combination thereof from a product stream;
- optionally a line configured to conduct silicon tetrachloride removed into the first line;
- optionally a line configured to feed removed trichlorosilane fed to an end product removal process;
- optionally a line configured to conduct hydrogen removed into the second line;
- and
- optionally a line configured to remove HCl and to feed the HCl to a silicon hydrochlorinating plant,
- wherein the plant is suitable for reacting silicon tetrachloride with hydrogen to form trichlorosilane.
8 more elements
Dependencies are inferred from the claim text.