Hydrodynamic Flow Characteristics in an Internally Circulating Fluidized Bed Gasifier

Abstract

In this paper, the hydrodynamic flow inside an internally circulating fluidized bed (ICFBG) was characterized using experimental and three-dimensional computational fluid dynamics (CFD) models. Eulerian-Eulerian model (EEM) incorporating the kinetic theory of granular flow was implemented in order to simulate the gas–solid flow. A full-scale plexiglass cold flow experimental model was built to verify simulation results prior to the fabrication of the gasifier. Six parameters were manipulated to achieve the optimum design geometry: fluidization flow rate of the draft tube (Qdt), aeration flow rate of the annulus (Qan), initial bed static height (Hbs), draft tube height (Hdt), draft tube diameter (Ddt), and orifice diameter (Dor). The investigated parameters showed strong effect on the particle flow characteristics in terms of the pressure difference (ΔP) and solid circulation rate (Gs). The predicted results by simulation for the optimum case were in close agreement with experimental measurements with about 5% deviation. The results show that the ICFBG operated stably with the maximum Gs value of 86.6 kg/h at Qdt of 350 LPM, Qan of 150 LPM, Hbs of 280 mm, Hdt of 320 mm, Ddt of 100 mm, and Dor of 20 mm.

Numerical Investigation on Hydrodynamic Combustion and NOx Emission Behavior in 8 MW Circulating Fluidized Bed

“…They have used the FLUENT 6.3 software for CFD simulations in the study that used EulerianEulerian model for solid particle flow. The study noted that, in compliance with the experimental results and simulation results, it was stated that the fluidization in the simulation was affected by flow rate in the flow pipe, air flow rate, initial bed static height, and the orifice diameter [11].…”

Bioenergy as an Alternative Energy Source: Progress and Development to Meet the Energy Mix in Indonesia

“…Some of the tested agricultural residues in gasifiers and stoves shown in Figure 4 include (a) Candlenut shells, (b) Peat soils, (c) Sawdust, and (d) Coconut shells. Figure 4e shows the gasification with sawdust as feedstock with a novel internally circulating fluidized bed which can achieve stable gas production with heating value of about 7 MJ/m 3 [101,102]. Fixed-bed type gasifier was also tested using candlenut shell and coconut shell which can be used to produce flammable gas as shown in Figure 4f [103].…”

Steam Gasification of Biomass for Hydrogen Production – A Review and Outlook

“…Currently, two main types of fluidized bed gasifiers are used: a) circulation bed, b) bubbling bed [67]. Internal circulating fluidized bed was proposed to provide some of the advantages of the other two FB types, but still being under research and development stage [68].…”