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US 5,918,481 AGranted
Process for separating hydrogen fluoride from fluorocarbons
AssigneeAlliedSignal Inc.
InventorsHang Thanh Pham, Rajiv Ratna Singh, Hsueh Sung Tung, Daniel Christopher Merkel, David Goldschmidt, Tadeusz Piotr Rygas
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Abstract
The invention provides a method for separating fluorocarbons from mixtures of fluorocarbon and hydrogen fluoride. In particular, the invention provides a method for separating fluorocarbons, such as pentafluoropropane, from azeotropic mixtures of the fluorocarbon and hydrogen fluoride using compositional variations with pressure.
Claims22
A process comprising the steps of:
- (A) distilling a mixture comprising at least an azeotropic mixture of a fluorocarbon and hydrogen fluoride at a first pressure to produce a first overhead stream enriched in either the fluorocarbon or the hydrogen fluoride and a first bottoms stream enriched in the other component;
- and
- (B) redistilling the first overhead stream at a second pressure to produce a second overhead stream enriched in the component enriched in the first bottoms stream and a second bottoms stream enriched in the component enriched in the first overhead stream.
A process comprising the steps of:
- (A) distilling a mixture comprising at least an azeotropic mixture of a C.sub.3 to C.sub.5 alkane or alkene containing at least one fluorine atom and hydrogen fluoride at a first pressure to produce a first overhead stream enriched in either the fluorocarbon or the hydrogen fluoride and a first bottoms stream enriched in the other component;
- and
- (B) redistilling the first overhead stream at a second pressure to produce a second overhead stream enriched in the component enriched in the first bottoms stream and a second bottoms stream enriched in the component enriched in the first overhead stream
- wherein the first distillation pressure is from about 50 to about 400 psia and the second distillation pressure is from about 5 psia to about 50 psia.
1 more element
A process comprising the steps of:
- (A) distilling a mixture comprising at least an azeotropic mixture of a C.sub.3 to C.sub.5 alkane or alkene containing at least one fluorine atom and hydrogen fluoride at a first pressure to produce a first overhead stream enriched in either the fluorocarbon or the hydrogen fluoride and a first bottoms stream enriched in the other component;
- and
- (B) redistilling the first overhead stream at a second pressure to produce a second overhead stream enriched in the component enriched in the first bottoms stream and a second bottoms stream enriched in the component enriched in the first overhead stream
- wherein the first distillation pressure is from about 5 psia to about 50 psia and the second distillation pressure is from about 50 to about 400.
1 more element
Dependencies are inferred from the claim text.