Stationary States in a Nonisothermal Continuous Stirred-Tank Reactor

steady states

reactor dynamics

steady states :

ξ vs. θ

T vs. θ

reactor dynamics :

ξ vs. time

T vs. time



33.96

initial temperature in Kelvin

328

residence time

60

This Demonstration analyzes the single-step reaction

AB+Δ

H

rxn

in a nonisothermal continuous well-stirred tank reactor (CSTR) where

Δ

H

rxn

is the heat of reaction. The rate of reaction is first order in the concentration of species

A

, so that

r=k(T)

C

A

, and the rate constant has an Arrhenius temperature dependence:

k(T)=

k

m

exp-

1

T

-

1

T

m



. Heat is removed from the reactor using a cooling coil that has an overall heat transfer coefficient



and surface area



. The Demonstration shows the complex steady states (expressed as plots of temperature

T

versus

θ

, and conversion fraction

ξ

versus

θ

) that can occur in the reactor as the residence time

θ

and the heat transfer parameter

=/V

are varied. The possibilities include a unique steady state and multiple steady states, as well as the birth and death of an isola (or island), which is a region in the solution space described by a closed loop.

You can study the dynamics of the reactor by varying the initial temperature for the reactor

T(0)=

T

in

. When multiple steady states are present, each stable steady state will have a zone of attraction that you can explore by changing

T

in.