%0 Journal Article
%T Implementation of a Demoisturization and Devolatilization Model in Multi-Phase Simulation of a Hybrid Entrained-Flow and Fluidized Bed Mild Gasifier
%A Jobaidur Khan
%A Ting Wang
%J International Journal of Clean Coal and Energy
%P 35-53
%@ 2168-1538
%D 2013
%I Scientific Research Publishing
%R 10.4236/ijcce.2013.23005
%X <span>A</span><span> </span><span>mild gasification process has been implemented to provide an alternative form of clean coal technology called the Integrated Mild Gasification Combined Cycle (IMGCC), which can be utilized to build a new, highly efficient, and compact power plant or to retrofit an existing coal-fired power plant in order to achieve lower emissions and significantly improved thermal efficiency. The core technology of the mild gasification power plant lies on the design of a compact and effective mild gasifier that can produce synthesis gases with high energy volatiles through a hybrid system: utilizing the features of both entrained-flow and fluidized bed gasifiers. To aid in the design of the mild gasifier, a computational model has been implemented to investigate the thermal-flow and gasification process inside this mild gasifier using the commercial CFD (Computational Fluid Dynamics) solver ANSYS/FLUENT. The Eulerian-Eulerian method is employed to model both the primary phase (air) and the secondary phase (coal particles). However, the Eulerian-Eulerian model used in the software does not facilitate any built-in devolatilization model. The objective of this study is therefore to implement a devolatilization model (along with demoisturization) and incorporate it into the existing code. The Navier-Stokes equations and seven species transport equations are solved with three heterogeneous (gas-</span><span>solid) and two homogeneous (gas-gas) global gasification reactions. Implementation of the complete model starts from adding demoisturization first, then devolatilization, and then adding one chemical equation at a time until finally all reactions are included in the multiphase flow. The result shows that the demoisturization and devolatilization models are successfully incorporated and a large amount of volatiles are preserved as high-energy fuels in the syngas stream without being further cracked or reacted into lighter gases. The overall results are encouraging but require future experimental data for verification.</span><span></span>
%K Multi-Phase Simulation
%K Gasification Simulation
%K Entrained-Flow Gasifier
%K Fluidized Bed Mild Gasifier
%K Clean Coal Technology
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=36046