Conceptual Coupled Process for Catalytic Cracking of High-Acid Crude Oil

To process high-acid crude oil by catalytic cracking technology, a coupled process (FCD–FCC) involving fluid catalytic deacidification (FCD) of high-acid crude oil over a spent catalyst and fluid catalytic cracking (FCC) of heavy oil over a regenerated catalyst was proposed. Experiments were carried out in a confined fluidized bed reactor to test the feasibility of this process. The results indicate that the spent catalyst can be used for deacidification of high-acid crude oil to restrain the overcracking of light fractions. The optimal reaction conditions for the catalytic deacidification of Dar acidic crude oil are a temperature of 460 °C, a catalyst-to-oil ratio of 5, and a spent catalyst with a coke content of 1.26 wt %. Compared with the direct catalytic cracking of Dar crude oil over a regenerated catalyst, the yields of light oil and desired product increased by 6.10 and 6.78 wt % in the FCD–FCC process, respectively, and the olefin content of naphtha decreased by approximately 16 wt %, although the naphtha yield was lowered by 2.9 wt %. This strategy sheds new light on the processing of high-acid crude oil.