Moving bed coal gasifier dynamics

Moving Bed Coal Gasifier Dynamics Using MOC and MOL Techniques... 

The continuity equations for mass and energy will be used to derive the hyperbolic partial differential equation model for the simulation of moving bed coal gasifier dynamics. Plug flow (no axial dispersion) and adiabatic (no radial gradients) operation will be assumed. 

Some work has already been done on the simulation of transient behavior of moving bed coal gasifiers. However, the analysis is not based on the use of a truly dynamic model but instead uses a steady state gasifier model plus a pseudo steady state approximation. For this type of approach, the time response of the gasifier to reactor input changes appears as a continuous sequence of new steady states. 

The continuity equations for mass and energy were used to derive an adiabatic dynamic plug flow simulation model for a moving bed coal gasifier. The resulting set of hyperbolic partial differential equations represented a split boundary-value problem. The inherent numerical stiffness of the coupled gas-solids equations was handled by removing the time derivative from the gas stream equations. This converted the dynamic model to a set of partial differential equations for the solids stream coupled to a set of ordinary differential equations for the gas stream. 

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