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:
Apr. 02, 1996
Filed:
Jan. 09, 1995
Frank D McCarthy, Wayne, NJ (US);
Stephen J Stanley, Matawan, NJ (US);
David M Wadsworth, Laconia, NH (US);
ABB Lummus Crest Inc., Bloomfield, NJ (US);
Abstract
A low pressure cryogenic process is disclosed for recovering C.sub.2 and heavier hydrocarbons and particularly olefins from a refinery offgas containing hydrogen, methane, nitrogen oxide in addition to the C.sub.2 and heavier hydrocarbons. The conventional high pressures are eliminated and the temperatures are maintained higher than the temperature at which nitrated gums can form while still maintaining high olefin recovery. The feed is deethanized or depropanized to remove the C.sub.4 and heavier hydrocarbons at a temperature above the nitrated gum formation temperature. The overhead is then demethanized in a column using an enriching zone above the rectifying zone with a feed of C.sub.2 or heavier paraffins between these two zones.