Catalytic Cracking of Undesirable Components in a Coking Process

Abstract

Undesirable gas oil components are selectively cracked or coked in the coking vessel by injecting an additive into the vapors of traditional coking processes in the coking vessel prior to fractionation. The additive contains catalyst(s), seeding agent(s), excess reactant(s), quenching agent(s), carrier(s), or any combination thereof to modify reaction kinetics to preferentially crack or coke these undesirable components that typically have a high propensity to coke. These undesirable gas oil components are often precursors to coke in the coking process and as coke on catalyst in downstream catalytic cracking processes. These components often contain elements that cause catalyst deactivation in downstream catalytic units, as well. Exemplary embodiments of the present invention also provide methods to control the (1) coke crystalline structure and (2) the quantity and quality of volatile combustible materials (VCMs) in the resulting coke. That is, by varying the quantity and quality of the catalyst, seeding agent, and/or excess reactant the process may effect the quality and quantity of the coke produced, particularly with respect to the crystalline structure (or morphology) of the coke and the quantity & quality of the VCMs in the coke. For example, anode grade, sponge coke production may be maintained in delayed cokers, despite higher levels of heavy, sour crudes in the refinery crude blend. In addition, the quantity and quality of the VCMs may be controlled to address the needs and specifications for certain coke markets. Pet coke from this process may have unique characteristics with substantial utility.

Dependencies are inferred from the claim text.