Web Labs at www.ReactorLab.net - by Richard K. Herz

Plug Flow Reactor with heat exchange jacket

Reactor. This is a dynamic (transient, unsteady-state) simulation of a plug flow reactor (PFR) packed with porous solid catalyst pellets. This type of reactor is called a packed bed reactor.

There is an annular heat exchange jacket surrounding the reactor. For simplicity, we specify that the temperature of the heat exchange fluid in the jacket is constant throughout the jacket. Energy may be transferred between the reactor and the heat exchange jacket for non-zero values of the heat exchange coefficient-area parameter UA. For "adiabatic" operation, set UA to zero.

Reaction. The reaction is A → products. The reaction is first-order in reactant. For simplicity, the reaction equilibrium composition is specified to be almost all product under all conditions, i.e., an essentially irreversible reaction. The concentration of reactant A is represented as Ca. Constant fluid density is assumed. Currently in this simulation, the only heat capacities which affect the dynamic response are that of the fluid and catalyst. The heat capacity of the reactor body may be added later.

Color image. With each change of input value, the color scale of the color image changes such that it can span the full range of temperatures which are possible for the current inputs. The color palette is that of Matlab's jet colormap, which ranges from blue at low values through green to red at high values.

Constant values. The fluid density and the catalyst pellet density = 1000 kg/m³. The void fraction in the catalyst bed between pellets is 0.30. The heat capacity of both the reactant and heat transfer fluids = 2.24 kJ/kg/K. The heat capacity of the catalyst pellets = 1.24 kJ/kg/K. Assume that the reactant fluid and catalyst are at the same temperature at each position in reactor. The heat capacity of the reactor walls is not considered in the dynamics here.