Separation, characterization and catalytic cracking kinetics of aromatic fractions obtained from FCC feedstocks

A modified ASTM-D-2549 method was used to separate and characterize the aromatic fraction contained in a fluid catalytic cracking (FCC) unit feedstock. The total aromatic fraction was firstly separated in many other fractions which were subsequently characterized and analyzed using a GC/MS system. The results of the separation scheme were found to be satisfactory. The total aromatic fraction, obtained by the above separation, and an FCC gasoline fraction from a commercial unit, were used as feedstocks in kinetic experiments. These experiments were carried out in a microactivity (MAT) reactor at relatively short residence times using an equilibrium cracking catalyst. From these experiments the cracking products distribution was measured as a function of Weight Hourly Space Velocity (WHSV) and time on stream. Based on these experimental results, a lump kinetic model was developed for gasoline and the aromatics fraction. The kinetic constants of this reaction scheme were estimated using a sequential step regression method.