Systems and methods for cracking hydrocarbons to produce light olefins

Abstract

Systems and processes for cracking hydrocarbons to produce light olefins include an FCC reactor utilizing counter-current flow that includes a reaction zone comprising an elongated reaction tube that has a feed inlet, a product outlet, and a catalyst inlet. In embodiments, the FCC reactor further includes a freeboard zone. The freeboard zone is configured to reduce a superficial velocity of the cracked hydrocarbon fluids in the reaction zone, causing catalyst entrained in the cracked hydrocarbon fluids to at least partially separate from the cracked hydrocarbon fluids. In embodiments, the FCC reactor includes a dense fluidized bed unit. The dense fluidized bed unit is configured to inject a fluidizing gas such that bubbles are formed within the solid particles of the dense fluidized bed of solid particles, which causes the catalyst to overflow from the dense fluidized bed of solid particles into the reaction zone.