Purification of halide
AssigneeEthyl Corporation
InventorsWarren B. Kirsch, Sebastian M. Laurent
Life of this patent
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Abstract
A process for the removal of hydrogen halides including HCl and HF, and/or sulfur dioxide from silicon tetrafluoride. Contaminated gaseous silicon tetrafluoride is passed through a column of zeolite preferably in the hydrogen cation form so as to permit recovery of silicon tetrafluoride containing less than about 10% of the original contamination levels. Acid-stable zeolite materials suitable for the process of the invention are subjected to a flow of hot gases to permit regeneration of the column for use in a semicontinuous process.
Claims23
A method of purifying gaseous silicon tetrafluoride contaminated with at least one member selected from the group consisting of sulfur dioxide and HX where X is a halide, said method comprising the steps of contacting gaseous silicon tetrafluoride with an acidstable mordenite zeolite that selectively removes said at least one member and recovering the purified gaseous silicon tetrafluoride.
A semicontinuous process for the removal of HX where X is a halide from a stream of gaseous silicon tetrafluoride containing a deleterious amount of HX, said process comprising the steps of:
- (a) passing said stream through a column packed with an acidstable mordenite zeolite stream with an HX content of less than about 10% of the original contamination until the column is so saturated that it permits breakthrough of HX above about 10% of the original contamination;
- (b) regenerating the column and recovering silicon tetrafluoride purified to less than about 10% of the stream contamination;
- and
- (c) repeating step a).
A semicontinuous process for the removal of sulfur dioxide from a stream of gaseous silicon tetrafluoride containing a deleterious amount of sulfur dioxide, said process comprising the steps of:
- (a) passing said stream through a column packed with an acidstable mordenite zeolite and recovering said stream with a sulfur dioxide content of less than about 10% of the original contamination until the column is so saturated that it permits breakthrough of sulfur dioxide above about 10% of the original contamination;
- (b) regenerating the column and recovering silicon tetrafluoride purified to less than about 10% of the stream contamination;
- and
- (c) repeating step a).
Dependencies are inferred from the claim text.