99/01974 Modeling freeboard gasification in fluidized bed gasifier (1). Model set-up: Tang, Z. et al. Ranshao Kexue Yu Jishu, 1998, 4, (2), 150–156. (In Chinese)

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A two-region model of a spouted bed gasifier devised by the present authors has been further developed to include an enthalpy balance. As before, the present model assumes first-order reaction kinetics for the gasification reactions and the spout is treated as a plug flow reactor of fixed diameter with cross flow of gas into the annulus. The annulus region is considered to be a single plug flow reactor. Solids move in plug flow in both annulus and spout, independent of temperature and reaction. The model allows predictions of axial profiles of temperature and gas in the spout and annulus as well as exit gas compositions and overall carbon conversion. The exit gas compositions were compared with those of the previous two-region and streamtube isothermal models. The effect of hydrodynamic parameters on model predictions are illustrated and a comparison made with experimental temperature profiles obtained in a 0.30 m diameter gasifier.