Page 14 - Modeling of Chemical Kinetics and Reactor Design

MIXING

An important unit operation in chemical reaction engineering,
mixing, finds application in petrochemicals, food processing, and
biotechnology. There are various types of fluid mixing such as liquid
with liquid, gas with liquid, or solids with liquid. The text covers
micromixing and macromixing, tracer response and residence time
distribution (RTD), heat transfer, mixing fundamentals, criteria for
mixing, scale of segregation, intensity of segregation, types of impellers,
dimensional analysis for liquid agitation systems, design and scale-up
of mixing pilot plants, the use of computational fluid dynamics (CFD)
in mixing, and heat transfer in agitated vessels.

BIOCHEMICAL REACTION

This is an essential topic for biochemists and biochemical engineers.
Biochemical reactions involve both cellular and enzymatic processes,
and the principal differences between biochemical and chemical
reactions lie in the nature of the living systems. Biochemists and
biochemical engineers can stabilize most organic substances in processes
involving microorganisms.
This chapter discusses the kinetics, modeling and simulation of
biochemical reactions, types and scale-up of bioreactors. The chapter
provides definitions and summary of biological characteristics.

CHEMICAL REACTOR MODELING

This involves knowledge of chemistry, by the factors distinguishing
the micro-kinetics of chemical reactions and macro-kinetics used to
describe the physical transport phenomena. The complexity of the
chemical system and insufficient knowledge of the details requires that
reactions are lumped, and kinetics expressed with the aid of empirical
rate constants. Physical effects in chemical reactors are difficult to
eliminate from the chemical rate processes. Non-uniformities in the
velocity, and temperature profiles, with interphase, intraparticle heat,
and mass transfer tend to distort the kinetic data. These make the
analyses and scale-up of a reactor more difficult. Reaction rate data
obtained from laboratory studies without a proper account of the
physical effects can produce erroneous rate expressions. Here, chemical
reactor flow models using mathematical expressions show how physical

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