A method of recovering catalyst performance includes providing a vanadium selective catalytic reduction (VSCR) catalyst. The method includes exposing the VSCR catalyst to a first humidity level in a range of 50%-100% relative humidity, at a first temperature in a range of 20° C.-100° C., for a first period of time of at least two hours. The method includes thermally treating the VSCR catalyst at a second temperature in a range of 300° C.-600° C. for a second period of time of at least than one hour.

A process for upgrading a hydrocarbon feed to produce light olefins, includes contacting the hydrocarbon feed with steam in the presence of a cracking catalyst in a steam catalytic cracking reactor at reaction conditions sufficient to cause at least a portion of the hydrocarbons in the hydrocarbon feed to undergo one or more cracking reactions to produce a steam catalytic cracking effluent comprising ethylene, propylene, or both, wherein the process is capable of being transitioned between an ethylene-selective mode and a propylene-selective mode; determining whether to produce ethylene or propylene; when producing ethylene, then operating the process in ethylene-selective mode comprises producing more ethylene than propylene; or when producing propylene, then operating the process in propylene-selective mode comprises producing more propylene than ethylene.

A process for upgrading a hydrocarbon feed to produce light olefins, includes contacting the hydrocarbon feed with steam in the presence of a cracking catalyst in a steam catalytic cracking reactor at reaction conditions sufficient to cause at least a portion of the hydrocarbons in the hydrocarbon feed to undergo one or more cracking reactions to produce a steam catalytic cracking effluent comprising ethylene, propylene, or both, wherein the process is capable of being transitioned between an ethylene-selective mode and a propylene-selective mode; determining whether to produce ethylene or propylene; when producing ethylene, then operating the process in ethylene-selective mode comprises producing more ethylene than propylene; or when producing propylene, then operating the process in propylene-selective mode comprises producing more propylene than ethylene.

A process for combusting coke from catalyst in partial burn mode is disclosed. The partial burn regenerator runs deprived of oxygen such that the flue gas will contain a fair amount of carbon monoxide. The oxygen present in the flue gas can burn in the bed before reaching the dilute phase. The catalyst distributor is positioned in the upper chamber of the regeneration vessel for discharging the catalyst.

A method of recovering catalyst performance includes providing a vanadium selective catalytic reduction (VSCR) catalyst. The method includes exposing the VSCR catalyst to a first humidity level in a range of 50%-100% relative humidity, at a first temperature in a range of 20? C.-100? C., for a first period of time of at least two hours. The method includes thermally treating the VSCR catalyst at a second temperature in a range of 300? C.-600? C. for a second period of time of at least than one hour.

A process for combusting coke from catalyst in partial burn mode is disclosed. The partial burn regenerator runs deprived of oxygen such that the flue gas will contain a fair amount of carbon monoxide. The oxygen present in the flue gas can burn in the bed before reaching the dilute phase. The catalyst distributor is positioned in the upper chamber of the regeneration vessel for discharging the catalyst.

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.

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.