Palm kernel shell is an important bioenergy resource in Thailand. However, due to elevated alkali content in biomass ash, this oil palm residue shows high tendency to bed agglomeration in a fluidized-bed combustion system using conventional bed material (silica sand). In this study, palm kernel shell was burned in the conical fluidized-bed combustor (FBC) using alumina and dolomite as alternati...

Investigations into drying kinetics of biomass in fluidized bed dryers are essential for the control processes, enhancing productivity and reducing energy consumption. However, there is limited research on characteristics at different bubble locations due to complex hydrodynamics around bubbles bed. In this paper, a new method proposed by combining electrostatic sensing digital imaging techniqu...

A bench-scale updraft gasifier was used as a fluidized- and fixed-bed gasification unit in three modes (fluidized-bed at equivalence ratios (ER) =0.2 and 0.25, and a mode in fixed-bed). The experiments were done in five different temperatures (650, 700, 750, 800 and 850oC). To obtain the required data to develop a thermodynamic equilibrium model, the proximate and ultimate analysis w...

We demonstrate that a fluidized bed of hard spheres during defluidization displays properties associated with formation of a glass. The final state is rate dependent, and as this state is approached, the bed exhibits heterogeneity with increasing time and length scales. The formation of a glass results in the arrest of macroscopic particle motion and thus the loss of fluidization. Microscopic m...

We demonstrate that a fluidized bed of hard spheres undergoes a glass transition during defluidization. As in other glass-forming systems, the dynamics of the bed becomes heterogeneous as the transition is approached; spatial and temporal correlation scales increase rapidly. Microscopic motion persists in the glass state, but the bed can be jammed (all motion arrested) by application of a small...

Size enlargement of fine powders by wet granulation involves mixing of fine particles with a binder liquid to form larger wet granules and drying them by evaporation of the binder liquid to form larger dry granules. Identification of the time for completion of granulation process is critical as further mixing of dry granules is providing extra energy for their attrition. In a batch fluidized be...

Fluidized beds have been widely used in power generation and in the chemical, biochemical, and petroleum industries. The 3D simulation of commercial scale fluidized beds has been computationally impractical due to the required memory and processor speeds. However, in this study, 3D Computational Fluid Dynamics simulation of a gas-solid bubbling fluidized bed is performed to investigate the effe...

The hydrodynamics in a 152 mm ID bubbling fluidized bed filled with 500-600 μm glass beads have been simulated using the computational fluid dynamics (CFD) code Fluent 6.3, and the results are compared to experimental data obtained using pressure measurements and 3D X-ray computed tomography. The grids in a Cartesian coordinate system used in simulations are made by 2D (8×8 mm, 4×4 mm, 2×2 mm, ...