Patent ID: 8277639

Claim:
A process for cracking a high TAN hydrocarbon feedstock comprising naphthenic acids, said high TAN hydrocarbon feedstock selected from (i) feedstock further comprising resid and having a TAN of at least 0.5 mg KOH/g oil (ASTM D-664); (ii) feedstock from a refinery pipestill having a TAN of at least 1.0 mg KOH/g oil (ASTM D-664) and having asphaltenes substantially removed therefrom; and (iii) mixtures thereof, said process comprising: a. heating said high TAN hydrocarbon feedstock in the convection section of a pyrolysis unit wherein steam is present to produce vapor phase; b. cracking said vapor phase in a radiant section of a pyrolysis furnace to produce an effluent comprising olefins, said furnace comprising a convection section and a radiant section; with the proviso that when said feedstock comprises non-volatiles including substantial amounts of asphaltenes, said process further comprises passing said high TAN hydrocarbon feedstock from step (a) through a flash drum prior to step (b).