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:
Aug. 26, 2003
Filed:
May. 09, 2002
John Douglas Oakey, Godalming, GB;
The BOC Group plc, Windlesham, GB;
Abstract
A method of forming a methane product by rejecting nitrogen from a feed gas stream comprising methane and nitrogen is disclosed. After being cooled in a main heat exchanger, the feed gas stream is rectified in a double rectification column comprising a higher pressure column and a lower pressure column. A gas flow is recycled from the lower pressure column to the higher pressure column. Part of the recycle flow is compressed in a compressor, cooled, liquefied in a condenser-reboiler and introduced into the higher pressure column. Another part of the recycle flow is also compressed in the compressor, cooled, liquefied in the main heat exchanger or by expansion, and introduced into the double rectification column in liquid state. At least part of the cooling of both parts of the recycle gas is performed in the main heat exchanger. A liquid methane product is withdrawn from the lower pressure column.