What is the effect of turbulent flow on reaction kinetics? Will turbulent flow be more reaction limited?

Question

What is the effect of turbulent flow on reaction kinetics? Will turbulent flow be more reaction limited?

Answer 1

I'm assuming you're talking about PFR's here.  One of the major assumptions when modeling a PFR is that you have perfect mixing in the radial direction (from the center to the wall) but none in the axial direction (along the path of flow).  With turbulent flow there will be some mixing in the axial direction, with the degree of turbulence determining whether or not its signifigant.  Where it really comes into play though is in your residence time.  Instead of being able to easily calculate how long a particle spends in the reactor you will have to use a time average, which results in a non-exact answer to the governing differential equation.  Other variables that no longer can be assigned exact values include linear velocity.  This makes the math a lot messier, but you can still solve.

Generally speaking, turbulent flow means better mixing, which means more atomic collisions, which means faster reactions.