The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 07, 2000
Filed:
Mar. 23, 1998
Iosif Chernyakov, Fort Lee, NJ (US);
Thomas Hsiao-Ling Hsiung, Emmaus, PA (US);
Alexander Schwarz, Bethlehem, PA (US);
James Hsu-Kuang Yang, Allentown, PA (US);
Air Products and Chemicals, Inc., Allentown, PA (US);
Abstract
A method for the separation and recovery of fluorochemicals from a gas stream containing a diluent gas and fluorochemicals by first contacting the gas stream with a membrane system in one or more stages where the membrane(s) is selectively more permeable to the diluent gas than the fluorochemicals to result in a permeate stream rich in diluent gas and retentate rich in fluorochemicals, thereafter subjecting retentate the gas stream to a purification by distillation or adsorption resulting in a product stream enriched in fluorochemicals and a purified diluent stream. The purified diluent stream is used as a purge stream and/or a recycle stream together with the permeate stream to a vacuum pump upstream of the membrane separation step. A product stream can be produced from a similar gas stream containing diluent gas and fluorochemical by an adsorption step combined with a subsequent distillation step where the purified diluent from the adsorption step is used as a purge stream and/or wholly or partial combined with a purified diluent stream from the distillation step as a recycle stream introduced into the process upstream of the adsorption step. Enriched fluorochemical and an enriched diluent streams can be produced from a stream containing diluent gas and fluorochemicals by cryogenic distillation with the enriched diluent stream recycled to the process upstream of the distillation step.