Processes for producing petrochemical products that utilize fluid catalytic cracking

A process for operating a hydrocarbon feed conversion system for producing a petrochemical product stream from a hydrocarbon feed stream, the process comprising:

• introducing the hydrocarbon feed stream to a feed separator;
• separating the hydrocarbon feed stream into at least a lesser boiling point fraction stream, a medium boiling point fraction stream, and a greater boiling point fraction stream in the feed separator;
• passing the greater boiling point fraction stream to a first fluidized catalytic cracking unit;
• passing the lesser boiling point fraction stream and the medium boiling point fraction stream to a second fluidized catalytic cracking unit, wherein the lesser boiling point fraction stream is passed into the second fluidized catalytic cracking unit upstream of the medium boiling point fraction stream;
• cracking at least a portion of the greater boiling point fraction stream in the first fluidized catalytic cracking unit in the presence of a first catalyst at a reaction temperature of from 500° C. to 700° C. to produce a first cracking reaction product stream;
• cracking at least a portion of the lesser boiling point fraction stream and the medium boiling point fraction stream in the second fluidized catalytic cracking unit in the presence of a second catalyst and at a reaction temperature of from 500° C. to 700° C. to produce a second cracking reaction product stream;
• and
• separating the petrochemical product stream from one or both of the first cracking reaction product stream or the second cracking reaction product stream,
• wherein the lesser boiling point fraction stream is initially exposed to greater temperatures in the second reactor unit, initially has a greater catalyst:oil ratio in the second reactor unit, has a greater residence time in the second reactor unit, or combinations thereof, as compared to the medium boiling point fraction stream.