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:
Jul. 29, 2008
Filed:
Sep. 21, 2004
Tom N. Kalnes, LaGrange, IL (US);
Daniel H. Wei, Naperville, IL (US);
Bryan K. Glover, Algonquin, IL (US);
Tom N. Kalnes, LaGrange, IL (US);
Daniel H. Wei, Naperville, IL (US);
Bryan K. Glover, Algonquin, IL (US);
UOP LLC, Des Plaines, IL (US);
Abstract
The average cycle propylene selectivity of an oxygenate to propylene (OTP) process using one or more fixed or moving beds of a dual-function oxygenate conversion catalyst with recycle of one or more C+ olefin-rich fractions is substantially enhanced by the use of selective hydrotreating technology on these C+ olefin-rich recycle streams to substantially eliminate detrimental coke precursors such as dienes and acetylenic hydrocarbons. This hydrotreating step helps hold the build-up of detrimental coke deposits on the catalyst to a level which does not substantially degrade dual-function catalyst activity, oxygenate conversion and propylene selectivity, thereby enabling a substantial improvement in propylene average cycle yield. The propylene average cycle yield improvement enabled by the present invention over that achieved by the prior art using the same or a similar catalyst system but without the use of the hydrotreating step on the C+ olefin-rich recycle stream is of the order of about 1.5 to 5.5 wt-% or more.