Dual riser fluid bed process and reactor

A dual riser fluidized catalytic cracking process, comprising:

• converting a first feed comprising at least about 60 wt % methanol in a first riser under a first set of process conditions to produce a first effluent enriched in ethylene, propylene, or a mixture thereof, wherein the first effluent comprises at least about 25 wt % dry basis propylene, and wherein at least about 50 wt % of the first feed is converted to ethylene, propylene, or the mixture thereof;
• converting a second feed comprising C4-C10 light hydrocarbons in a second riser under a second set of process conditions to produce a second effluent enriched in ethylene, propylene, or a mixture thereof, wherein at least about 40 wt % of the second feed is converted to ethylene, propylene, or the mixture thereof;
• combining the first effluent with the second effluent to produce a mixed effluent;
• separating the mixed effluent to produce a coked-catalyst and a gaseous product;
• regenerating the coked-catalyst by combusting the coke in a regenerator to produce a regenerated catalyst;
• recycling the regenerated catalyst to the first and second risers;
• separating C4-C10 hydrocarbons from the gaseous product;
• and
• recycling the C4-C10 light hydrocarbons to the second riser.

A dual riser fluidized catalytic cracking process comprising:

• converting a first feed comprising at least about 80 wt % methanol in a first riser comprising a zeolite ZSM-5 catalyst under a first set of process conditions to produce a first effluent enriched in ethylene, propylene, or a mixture thereof, wherein the first effluent comprises at least about 25 wt % dry basis propylene, and wherein at least about 50 wt % of the first feed is converted to ethylene, propylene, or the mixture thereof;
• converting a second feed comprising C4-C10 light hydrocarbons in a second riser comprising a zeolite ZSM-5 catalyst under a second set of process conditions to produce a second effluent enriched in ethylene, propylene, or the mixture thereof, wherein at least about 40 wt % of the second feed is converted to ethylene, propylene, or the mixture thereof;
• combining the first effluent with the second effluent to produce a mixed effluent;
• separating the mixed effluent to produce a coked-catalyst and a gaseous product;
• regenerating the coked-catalyst by combusting the coke in a regenerator to produce a regenerated zeolite ZSM-5 catalyst;
• recycling the regenerated zeolite ZSM-5 catalyst to the first and second risers;
• and
• fractionating the gaseous product to produce a stream comprising heavy naphtha and a stream comprising olefins.