(442a) CFD Modeling of gas-liquid-solid flow in a circulating fluidized bed Conference: AIChE Annual MeetingYear: 2015Proceeding: 2015 AIChE Annual MeetingGroup: Particle Technology ForumSession: Poster Session: Particle Technology Forum Time: Tuesday, November 10, 2015 - 6:15pm-8:00pm Authors: Liu, Y., Changzhou University Yang, J., Changzhou University La, X., Gao, J., State Key Laboratory of Heavy Oil Processing, China University of Petroleum(Beijing) CFD Modeling of gas-liquid-solid flow in a circulating fluidized bed Circulating fluidized bed is extensively used in many industrial applications such as fluidized catalytic cracking (FCC) riser. The detailed investigation of the flow circumstances in the fluidized bed is important to the process optimization. As Geldart A paticles, FCC catalysts make the simulation of the flow conditions difficult because of the agglomeration phenomena. Many models have been developed to represent the gas and solid interactions among which EMMS model proposed by Li et al. has been proved to be applicable. With the increasing of resid-ratio in the FCC feedstock, the heavy component which is hard to vaporize can no longer be ignored. However, most studies until now has assumed that the atomized feed oil vaporized instantaneously and totally in the riser. Li et al. model the interactions between hot particles and cold droplets in an evaporative spray riser considering the momentum exchange between the gas, solid and liquid pahse. However, the adopted Gidaspow correlation is not applicable for characterizing the whole gas and solid flow in the riser. In this paper, using the gas-liquid drag model proposed by Issa and Oliveira and the liquid-solid model by Ge and Fan. which has also been employed by Li et al., coupling the EMMS method, a compositive flow model has been developed to reveal the gas-liquid-solid flow in the FCC riser. It can be seen from Fig.1 that the solid volume fraction exhibits turbulent flow characteristics with the lower dense bed and the upper dilute bed. The liquid phase shows double-peak distributions, as plotted in Fog.2. There are many droplets accumulates at the bottom of the riser which will undoubtedly influence the FCC reaction effect. Fig.1 Solid volume fraction distributions Fig.2 Liquid volume fraction distributions  N. Yang, W. Wang, W. Ge, et al. CFD simulation of concurrent-up gas-solid flow in circulating fluidized beds with structure-dependent drag coefficient. Chem Eng J. 2003, 96: 71-80.  T. Li, K. Pougatch, M. Salcudean, et al. Numerical modeling of an evaporative spray in a riser. Powder Technology. 2010, 201:213-229.  R.L. Issa, P.J. Oliveira. Validation of two-fluid model in shear-free mixing layers. ASME- PUBLICATIONS- FED. 1996, 236:112-120.  Y. Ge, L.S. Fan. Three-dimensional direct numerical simulation for film-boiling contact of moving particle and liquid droplet. Physics of Fluids. 2006, 18:11.