US 9,890,334 B2 · Fluid catalytic cracking unit with low emissions

Abstract

An FCC unit enables the normal regenerator to be eliminated by carrying out catalyst regeneration in the reactor section of the unit using air, oxygen-enriched air or even relatively pure oxygen as the stripping medium in the stripping section of the reactor while maintaining overall reducing conditions so that sulfur and nitrogen are produced in the form of hydrogen sulfide, ammonia and other reduced species. The combustion gases from the stripper are sent from the reactor with the cracking vapors to the FCC main fractionator, wet gas compressor and gas plant to process the by-products of the coke combustion along with the FCC reactor effluent. The principle is applicable to grass-roots FCC units with its potential for elimination of a major unit component but it also has potential for application to existing units to reduce the load on the regenerator or eliminate the need for the existing regenerator so that an existing regenerator may be converted to a parallel or auxiliary reactor system.

Claims20

Dependent claims

A fluid catalytic cracking process in which a heavy oil feed is cracked, which comprises:

contacting a stream of heavy oil feed with a stream of hot, particulate cracking catalyst to crack the feed to form cracked hydrocarbon products of lower boiling range while depositing coke on the catalyst to form spent catalyst containing occluded hydrocarbons;
separating the cracked hydrocarbon products from the spent catalyst;
contacting the spent catalyst in a hydrocarbon stripping zone comprising at least one cyclone with an oxygen-containing gas to combust the coke deposited on the catalyst to strip occluded hydrocarbons from the spent catalyst and regenerate the spent catalyst by combustion of the coke on the catalyst, so forming a regenerated catalyst at a higher temperature;
and
directly passing the regenerated catalyst from the stripping zone into contact with a stream of heavy oil feed.

2 more elements

A fluid catalytic cracking unit for the production cracked hydrocarbons from a heavy oil feed, which comprises:

a cracking zone in which the heavy oil feed is contacted with a hot cracking catalyst to crack the feed and form cracked hydrocarbons of lower boiling range while depositing coke on the catalyst to form spent catalyst containing occluded hydrocarbons;
a disengagement zone in which the cracked hydrocarbons are separated from the spent catalyst containing occluded hydrocarbons and deposited coke;
a stripping zone in direct communication with the disengagement zone for receiving spent catalyst containing occluded hydrocarbons and deposited coke directly from the disengagement zone, the stripping zone including a supply of an oxygen-containing stripping and regeneration gas and a sparger in the stripping zone with the oxygen-containing stripping and regeneration gas from the supply to strip occluded hydrocarbons from the spent catalyst and regenerate the spent catalyst by combustion of the coke on the catalyst, so forming a stripped, regenerated catalyst at a higher temperature;
and
a conduit for directly conveying the regenerated catalyst into contact with a stream of heavy oil feed in the cracking zone.

2 more elements

Dependencies are inferred from the claim text.

Fluid catalytic cracking unit with low emissions

Life of this patent

Fluid catalytic cracking unit with low emissions

Life of this patent

Abstract

Claims20