Lecture 1 Flashcards
For carrying out a particular chemical reaction, how do you choose an appropriate reactor?
the optimum reactor configuration and reactor size needs to be determined.
what is meant by reactor configuration?
shape of reactor and mode of operation
what are the three types of ‘ideal reactors’?
batch, cstr, pfr
what is a cstr reactor?
continuous stirred tank reactor
what is a pfr reactor?
plug flow reactor
what will we not consider in RE1 when we approach problems?
mass transfer limitations which appear between reactants or reactants and catayst. this approach is applicable to homogenous reactions or average reaction rates
non-ideal flow patterns
what is a batch reactor?
in a batch reactor the properties (T,P, compositions) change with time but can generally assumed constant in the reactor volume. if we assume the tank is ideally stirred ( i think the stirring would be infinitely fast)
what is a semi-batch reactor?
in a semi batch reactor on or more of the reactants is already in the feed. numerical approaches will be needed to solve this.
what is a CSTR?
in a CSTR the properties (T,P, compositions) are constant in the reactor volume. a steady state can be reached. assume homogenous in every volume element
when is a CSTR not at steady state
when the reactors starts, ends and if the operating conditions change
what is a PFR?
PFR is a reactor where the properties (T,P, compositions) are not constant in the reactor volume. however they are constant in every section perpendicular to the flow. a steady state can be reached. there in no agitation (stirrer) in a PFR
explain how a steady state can be reached in a PFR is there is no agitation.
the properties are not constant in the reactor volume like they are in a CSTR but they are constant in every section perpendicular to the flow. meaning that in every element of the cross sectional area the properties are constant. therefore, a steady state can be reached.
