Apparatus to reduce NO/sub chi/ emissions from a fluid catalytic cracking unit

Patent · Tue Aug 01 04:00:00 EDT 1989

OSTI ID:5335228

Herbst, J A; Owen, H; Schipper, P H

This patent describes an apparatus for reducing NO/sub chi/ in flue gas from a regenerator for regenerating a spent fluid catalytic cracking catalyst stream comprising a mixture of ZSM-5 catalyst and zeolite Y catalyst particles from a fluid catalytic cracking reactor to produce regenerated catalyst. The apparatus comprising: a first regenerator riser having an inlet in a lower portion thereof for regenerating a first mixture of the spent catalyst stream, a portion of regenerated catalyst and a first oxygen-containing stream by passing the first mixture therethrough and an outlet in an upper portion of the first riser for discharging a mixture of catalyst and first flue gas from the first riser; a second regenerator riser; means for separating and discharging the first mixture from the first riser and downwardly directing catalyst from the first mixture from the first riser to a first catalyst bed; means for withdrawing from the apparatus the first flue gas stream from the discharged first mixture; means for adding a second oxygen-containing stream to the first bed; means for passing a second mixture of catalyst and gases comprising the NO/sub chi/ from the first bed into the upper portion of the second riser; an enlarged catalyst collecting chamber above the first catalyst bed; means for discharging the second mixture from the second riser and downwardly directing the second mixture from the second riser to a second catalyst bed; means for separating a second flue gas stream from the second mixture prior to passing the second mixture into the second bed; means for adding a third oxygen-containing gas stream to the second bed; means for recycling regenerated catalyst from the second bed to the first riser; means for withdrawing regenerated catalyst from the second bed; and means for separating a third flue gas stream from an atmosphere of the collecting chamber above the second bed.

• Assignee: Mobil Oil Corp., New York, NY
• Patent Number(s): US 4853187
• Application Number: PPN: US 7-188817A
• OSTI ID: 5335228
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020400* -- Petroleum-- Processing
020900 -- Petroleum-- Environmental Aspects
54 ENVIRONMENTAL SCIENCES
540120 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
AIR POLLUTION CONTROL
CATALYTIC CRACKING
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMICAL REACTORS
CONTROL
CRACKING
DECOMPOSITION
EMISSION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MATERIALS
MINERALS
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
POLLUTION CONTROL
PYROLYSIS
SEPARATION PROCESSES
THERMOCHEMICAL PROCESSES
ZEOLITES