ABSTRACT
The mechanism of cracking reactions occurs through carbocations (carbenium ions) formed at the active acid sites of the catalyst. In addition to the formation of light products, during the catalytic cracking reactions deposits of high-molecular weight and high aromaticity coke occurs. This byproduct is subjected to controlled combustion in order to regenerate the catalyst activity. This combustion process is responsible for providing enough energy to carry out endothermic reactions of the feedstock during of the fluid catalytic cracking (FCC) process. The coke produced during cracking reactions can be classified according to the literature in five categories.
