Abstract:
Maximizing
iso-paraffins (MIP) process utilizes the technique of linking two reaction zones in series to effectively improve the gasoline quality. Aiming at the fluid catalytic cracking (FCC) riser reactor in MIP process, this paper considers the three-dimensional cold simulation problem of the flow behavior of gas-solid two-phase flow in reactor via Eulerian-Eulerian two-fluid model. The computational fluid dynamic (CFD) simulation is used to analyze the gas-solid flow characteristics of three zones in the riser reactor of MIP process, i.e., the pre-lifting zone, the first reaction zone, and the second reaction zone, which was made via the velocity distribution at different elevations, respectively. Moreover, the comparison with the flow characteristics inside the reactor is also made according to different ratios of catalyst to feed oil, i.e., 6, 7 and 8, respectively. It is shown from the simulation results that there exist typical non-uniform flow characteristics inside the riser reactor of MIP process. The flow in the pre-lifting zone shows a typical ring-core distribution. The maximum axial velocity of catalyst occurs in the region of about one quarter and three quarters of the radius in the first reaction. The second reaction zone has the same distribution characteristics as the first one, but the velocity of the second reaction zone is lower than that of the first one. As the ratio of catalyst to feed oil increases, both the axial velocity of the catalyst particles and the solid phase volume fraction increase.