EFFECT OF CATALYST CIRCULATION RATE ON THE BIFURCATION BEHAVIOR OF ANINDUSTRIAL FCC UNIT

The effect of catalyst circulation rate (17.721-150.63 kg/s) on the bi furcation behavior of an industrial fluid catalytic cracking (FCC) uni t is investigated for both the open loop as well as the closed loop sy stems. Five regions of qualitatively different bifurcation behavior ar e identified. For the open loop system it is found that decreasing the catalyst circulation rate stabilizes the point of maximum gasoline yi eld but higher values of air feed temperatures are required. The close d loop analysis shows that higher value of controller gains are requir ed to stabilize the point of maximum gasoline yield as the catalyst ci rculation rate is increased.