Dual fluid catalytic cracking reactor systems and methods for processing hydrocarbon feeds to produce olefins

A method for processing a hydrocarbon feed to produce olefins, the method comprising:

• introducing the hydrocarbon feed to a first fluid catalytic cracking system comprising a first cracking catalyst, the first cracking catalyst comprising a USY-zeolite having titanium, zirconium, or both substituted into the zeolite framework;
• contacting the hydrocarbon feed with the first cracking catalyst at a first cracking temperature greater than or equal to 480 degrees Celsius in the first fluid catalytic cracking system, the contacting causing at least a portion of the hydrocarbon feed to undergo catalytic cracking and produce a spent first cracking catalyst and a first cracked effluent comprising one or more olefins, where the first fluid catalytic cracking system comprises a downflow reactor;
• passing the first cracked effluent to a separation system downstream of the first fluid catalytic cracking system, where the separation system separates the first cracked effluent to produce at least a naphtha effluent comprising one or more olefins;
• passing the naphtha effluent to a second fluid catalytic cracking system downstream of the separation system, the second fluid catalytic cracking system comprising a cracking catalyst mixture comprising a second cracking catalyst and a cracking catalyst additive, where:
• the second cracking catalyst comprises a USY zeolite having titanium, zirconium, or both substituted into the zeolite framework;
• the cracking catalyst additive comprising a shape selective zeolite;
• the cracking catalyst mixture comprises 90 weight percent of the second cracking catalyst comprising the USY-zeolite, and 10 weight percent of the cracking additive comprising the shape selective zeolite;
• and
• contacting the naphtha effluent with the cracking catalyst mixture at a second cracking temperature greater than or equal to 580 degrees Celsius, the contacting causing at least a portion of the naphtha effluent to undergo catalytic cracking and produce a spent cracking catalyst mixture and a second cracked effluent comprising one or more olefins, where the second fluid catalytic cracking system comprises a downflow reactor, and the second cracking catalyst is different from the first cracking catalyst.