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. 18, 1979
Filed:
Oct. 20, 1977
James A Frayer, Pittsburgh, PA (US);
Harry C Stauffer, Cheswick, PA (US);
Stephen J Yanik, Valencia, PA (US);
Gulf Research and Development Company, Pittsburgh, PA (US);
Abstract
When residual oil is cracked to gasoline in the presence of a fluidized zeolite catalyst the oil is first catalytically hydrodesulfurized so that sulfur oxide emissions from the catalyst regenerator are held to environmentally acceptable levels. The hydrodesulfurized residual oil is flash vaporized at the elevated temperature at the inlet of the cracking riser and most of the residual oil feedstock passes into the vapor state and is cracked to valuable products. However, a portion of the 1050.degree. F.+ (566.degree. C.+) residual material cannot be flash vaporized at the riser temperature and instead deposits upon the catalyst and is coked. Data are presented which show that as the proportion of the 1050.degree. F.+ (566.degree. C.+) components in a cracking feedstock decreases, the amount of these high boiling components in each barrel of cracker feedstock which are flash vaporized can actually increase. A multistage hydrodesulfurization operation is provided in which the proportion of 1050.degree. F.+ (566.degree. C.+) residual components in the cracking feedstock is diminished whereby the amount of 1050.degree. F.+ (566.degree. C.+) residuals vaporized per barrel of feedstock during the subsequent cracking step is increased. The present method provides an interdependent advantage in the hydrodesulfurization operation since it reduces hydrogen consumption during hydrodesulfurization.