FCC RISER UNIT OPERATED IN THE HEAT-TRANSFER MODE - KINETIC MODELING

A pilot-plant unit, namely, Multicrackex, for the catalytic cracking o f hydrocarbons with the riser and regenerator units under direct heat exchange conditions was developed in the course of the present study. A two-levels pseudofactorial experimental program was designed using t he synthetic gas oil SF-135 (CANMET) and a commercial equilibrium cata lyst (Akzo Octaboost). Using the experimental temperature profile insi de the riser, the reaction rate constants and activation energies were evaluated for the four lump model. These parameters were precisely es timated (+/-7% average), and the adequacy of the model was tested by s tatistical analysis, showing model predictions inside the +/-15-20% er ror range. The experimental results and model predictions indicate tha t endothermic effects of the cracking reactions and gas oil vaporizati on are neutralized by the heat transfer from the regenerator to the ri ser.