Process for cracking hydrocarbons containing residual oil

Abstract

Abstract IN FLUID CATALYTIC RISER CRACKING OF A GAS OIL WITH A ZEOLITE CATALYST THE INCLUSION OF CONTROLLED AMOUNTS OF RESIDUAL OIL IN THE FEED RESULTS IN AN IMPROVEMENT IN OCTANE VALUE AND/OR IMPROVEMENT IN THE DISTRIBUTION OF OCTANE VALUE OF THE GASOLINE PRODUCT. THIS IMPROVEMENT IN OCTANE VALUE OCCURS PRIMARILY IN THE PARTICULAR BOILING RANGE FRACTIONS OF THE GASOLINE PRODUCT HAVING AT LOWEST OCTANE VALUE. HOWEVER, RESIDUAL OIL IS RELATIVELY DIFFICULT TO VAPORIZE AND THE EXTENT OF ITS VAPORIZATION WILL DEPEND ON THE EQUILIBRIUM FLASH VAPORIZATION TEMPERATURE AT THE BOTTOM OR INLET OF THE RISER. THE EQUILIBRIUM FLASH VAPORIZATION TEMPERATURE AT THE BOTTOM OF THE RISER IS GENERALLY LIMITED BY SUCH PROCESS NECESSITIES AS AVOIDANCE OF CATALYST SINTERING OR DEACTIVATION AND/OR AVOIDANCE OF EXCESSIVE CATALSYT TO OIL RATIOS, WHICH CAN ADVERSELY AFFECT PRODUCT SELECTIVELY. THEREFORE, THE QUANTITY OF RESIDUAL OIL IN THE FEED MUST BE CONTROLLED IN RELATION TO THE EQUILIBRIUM TEMPERATURE IN ORDER TO, ON THE ONE HAND, VAPORIZE AND CRACK A SUFFICIENT QUANTITY OF RESIDUAL OIL TO OBTAIN THE OCTANE IMPROVEMENT EFFECT, WHILE, ON THE OTHER HAND, KEEPING THE QUANTITY OF RESIDUAL OIL WHICH REMAINS UNVAPORIZED BELOW A SPECIFIED LEVEL. IT IS SHOWN THAT AT A FIXED EQUILIBRIUM FLASH VAPORIZATION TEMPERATURE THE QUANTITY OF RESIDUAL OIL WHICH IS VAPORIZED CANNOT BE INCREASED MERELY BY LARGE INCREASES IN THE PROPORTION OF RESIDUE IN THE FEED.

Inventors

• 👤 M Bryson
• 👤 J Mckinney
• 👤 R Titmus
• 👤 F White

Bibliographic Details