Ideal Reactors Flashcards
State what a batch reactor is good for.
Producing small amounts of materials.
Give the 4 advantages of a batch reactor.
high conversion per unit volume, easy to clean, flexibility of operation, low instrumentation cost
Give the 3 disadvantages of a batch reactor.
high labour and handling costs, considerable shut down time, poor quality control
State what a PFR is good for.
Large scale, fast reactions at high temperatures.
Give the 4 advantages of a PFR.
high conversion per unit volume, low operating costs, continuous operation, good heat transfer
Give the 3 disadvantages of a PFR.
undesired thermal gradients may exist, poor temperature control, shutdown and cleaning may be expensive
State what a CSTR is good for.
Reactions that require agitation or use different concentrations.
Give the 6 advantages of a CSTR.
continuous operation, good temperature control, easily adapts to two phase runs, good control, simplicity of construction, low operating costs, easy to clean
Give the 2 disadvantages of a CSTR.
lowest conversion per unit volume, by-passing and channelling possible with poor agitation
Give the 3 assumptions made to derive the batch reactor design equation.
- no flow in and no flow out during the reaction 2. perfectly mixed 3. generally constant pressure or volume
Derive the design equation for a batch reactor.
Which way does the line on a 1/r plot travel when concentration is on the x axis?
Downwards from left to right.
Which way does the line on a 1/r plot travel when conversion is on the x axis?
Upwards from left to right
Give the 4 assumptions made to derive the design equation for a CSTR.
- steady state (no accumulation)
- continuous flow in and out
- perfectly mixed
- product stream has the same concentration as the vessel contents
Derive the design equation for a CSTR.
Derive the design equation for a PFR.
Over a small control volume.
Define space-time.
The time taken to process one reactor volume of feed measured at a specific condition.
Define space-velocity.
The number of reactor volumes of ffeed at specific conditions which can be treated in a unit time.
