ON ASYMPTOTIC BEHAVIOR OF A TUBULAR REACTOR IN LIMIT OF SMALL AXIAL DIFFUSIVITY

An efficient procedure is presented for obtaining the asymptotic form of the longitudinal concentration profile existing in a tubular reactor with small axial diffusivity. The reaction rate expression can be arbitrary. It is shown that longitudinal diffusion causes the concentration at the inlet end to fall below the far-upstream value, causes a modest flattening of the concentration profile along the reactor, and causes the concentration profile at the outlet end to curve upward sufficiently to satisfy the zero-gradient boundary condition. © 1969.