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:
Dec. 07, 1993
Filed:
Mar. 16, 1992
David A Lomas, Barrington, IL (US);
Harold U Hammershaimb, Western Springs, IL (US);
Robert M Smith, Itasca, IL (US);
UOP, Des Plaines, IL (US);
Abstract
This invention provides a method of reducing the sulfur oxide emissions from the regenerator of an FCC process that cracks a sulfur containing feedstream. The sulfur oxide emissions are reduced by using an essentially sulfur free lift gas stream to shift the sulfur concentration equilibrium between the product stream from the reaction zone and the flue gas stream from the regeneration zone. Sulfur compounds present in the FCC feed leave the reaction zone as volatile sulfurous gases in the product vapor stream or as adsorbed sulfur compounds on the catalyst. Sulfurous gas in the product vapors is mainly H.sub.2 S. By lowering the concentration of H.sub.2 S that enters the riser with the lift gas the equilibrium reaction of sulfur with hydrogen in the riser is favorably shifted to increase the production of H.sub.2 S and decrease the lay down of sulfur compounds in the coke that forms on the catalyst. As a result less sulfur enters the regeneration zone with the spent catalyst and fewer sulfur oxides are formed during regeneration.