Preliminary Hydrodynamic Modeling of Fluidized Beds of Single Component and Binary Particle System in Compartmented Gasifier

Abstract

In the present study, three-dimensional simulation using computational fluid dynamics (CFD, FLUENT 6.3.26) and experiments were conducted on a transparent cold-flow gas-solid bubbling compartmented fluidized bed gasifier (CFBG) model with identical diameter as the pilot-scaled CFBG. Using Eulerian-Eulerian granular model with closure laws according to the kinetic theory of granular flow that based on modified drag model simulations were conducted to model the hydrodynamics of CFBG in terms of gas-solid flow pattern, bed expansion ratio, bed pressure drop and bubble diameter. The model was resolved by semi-implicit method for pressure-linked equation (SIMPLE) algorithm in CFD. Different inerts like river sand, quartz sand, and alumina were used to examine the hydrodynamics behaviors both in single component and binary system where biomass, palm shell, was mixed with river sand. The modeling predictions compared reasonably well with experimental bed expansion ratio measurements and qualitative gas-solid flow patterns. Pressure drops predicted by the simulations were in relatively close agreement with experimental measurements. Furthermore, the simulated bubble diameters showed similarities with the Darton et al., bubble size equation.

Keywords:

• binary system
• CFD
• fluidized bed
• hydrodynamics
• single component