Production Distribution and Multiple Reactions Flashcards
Give the four types of multiple reactions an example of each.
- series
- series parallel
- reversible + irreversible
- Denbigh system
What is the equation for instantaneous selectivity if A goes R and A goes to S, if R is the desired reactant?
In the instantaneous selectivity equation, if the order of a component is positive, what reactors are suitable and why?
A batch or PFR reactor to keep the concentration of the component high for as long as possible.
If mixed with components that require a low concentration, a semi-bath or semi-PFR reactor would be suitable, with the the component beginning in the reactor to keep it’s concentration high for as long as possible.
In the instantaneous selectivity equation, if the order of a component is negative, what reactors are suitable and why?
A CSTR is suitable because it will keep the concentration of the component low, which will increase the selectivity of the desired product.
If mixed with a component that need to be in a high concentration, a semi-batch or semi-PFR is suitable, with the component added slowly throughout the reaction in order to keep the concentration low.
How can product distribution (selectivity) be controlled by varying the k1/k2 ratio?
- changing the operation temperature. If the activation energies of the two reactions are different, a change in T will change the rate constant ratio.
- using a catalyst. One of the most important features of a catalyst is it’s selectivity in the depressing or accelerating specific reactions.
Define yield of a reaction.
The moles of a specific product formed per mole of reactant consumed.
State the equation for instantaneous fractional yield.
Which equations on the equation sheet are for overall fractional yield, and what is the difference between the two?
Equations 1 and 2. 1 is for the overall yield in a PFR, and 2 for a CSTR.
