Selectivity in experimental reactors

Abstract

Abstract Unpacked pipes or tubes, commonly called flow reactors , are often desirable for carrying out homogeneous reactions. Unless these reactors are properly designed and operated, axial mixing will alter both the rate of conversion and the distribution of products from successive reactions. Several hypothetical reaction schemes are analyzed here to show how axial mixing affects the production of an intermediate. The analysis represents mixing by an axial diffusion coefficient and is valid when mixing is not extreme. Results from several particular cases are compared, showing that reactor‐product distribution is generally distorted in proportion to a reactor Peclet number. G. I. Taylor's theory of axial mixing is used to relate this Peclet number to the physical characteristics of the reactor Although the effects of axial mixing are concluded to be negligible in most commercial or large‐scale equipment, they are serious in the case of experimental or pilot‐scale apparatus. Charts are drawn to illustrate design problems for these reactors.