초록 ▼

The present invention provides a process for recovering boron trifluoride from an impure gaseous boron trifluoride residue. The process comprises: (a) feeding an impure gaseous boron trifluoride residue containing sulfur dioxide as an impurity into a mixture of boric and sulfuric acids wherein the a

The present invention provides a process for recovering boron trifluoride from an impure gaseous boron trifluoride residue. The process comprises: (a) feeding an impure gaseous boron trifluoride residue containing sulfur dioxide as an impurity into a mixture of boric and sulfuric acids wherein the acid mixture absorbs boron trifluoride from the impure boron trifluoride residue and slightly absorbs or does not absorb sulfur dioxide from the impure gaseous boron trifluoride residue; and (b) removing the unabsorbed sulfur dioxide from the acid mixture. The present invention also provides a boron trifluoride preparation and purification process. The process comprises the steps of (a) reacting boric acid and fluorosulfuric acid in surfuric acid to form a product; (b) distilling the product from step (a) to yield pure boron trifluoride and impure gaseous boron trifluoride; (c) feeding the impure gaseous boron trifluoride residue containing sulfur dioxide as an impurity into a mixture of boric and sulfuric acids wherein the acid mixture absorbs boron trifluoride from the impure gaseous boron trifluoride residue and only slightly absorbs sulfur dioxide from the impure gaseous boron trifluoride residue; and (d) removing the unabsorbed sulfur dioxide from the acid mixture. The recovered boron trifluoride may be used as a catalyst.

대표청구항 ▼

A method for removing sulfur dioxide from a boron trifluoride stream comprising the steps of: (a) condensing a gaseous boron trifluoride stream; (b) distilling said condensed boron trifluoride stream to yield pure boron trifluoride and a liquid boron trifluoride residue wherein said liquid boron tri

A method for removing sulfur dioxide from a boron trifluoride stream comprising the steps of: (a) condensing a gaseous boron trifluoride stream; (b) distilling said condensed boron trifluoride stream to yield pure boron trifluoride and a liquid boron trifluoride residue wherein said liquid boron trifluoride residue comprises by weight: about 40 to about 95% boron trifluoride, about 5 to about 30% sulfur dioxide, about 0 to 19% sulfur trioxide, about 0 to about 0.2% silicon fluoride, about 0 to about 1.0% arsenic fluoride, and about 0 to about 0.1% antimony fluoride; (c) vaporizing said liquid boron trifluoride residue; (d) feeding said gaseous boron trifluoride residue into a mixture of boric and sulfuric acids wherein said acid mixture comprises by weight about 1 to about 30% boric acid and about 70 to about 99% sulfuric acid and absorbs boron trifluoride from said gaseous boron trifluoride residue and only slightly absorbs sulfur dioxide from said gaseous boron trifluoride residue; and (e) removing said unabsorbed sulfur dioxide from said acid mixture.