Table of Contents
Why does PFR require less volume than CSTR?
A PFR has a higher theoretical efficiency than a CSTR of the same volume. That is, given the same space-time (or residence time), a reaction will proceed to a higher percentage completion in a PFR than in a CSTR.
Why is CSTR better than PFR?
As can be seen from the figure, the ratio is always positive, indicating that to achieve the same fractional conversion, the volume of a CSTR must be larger than the volume of a PFR. At high fractional conversion values, the volume required for a CSTR increases rapidly compared the the volume of a PFR.
Which volume is larger the PFR or the CSTR explain why?
In CSTR the rate of the reaction is very slow and hence it requires more volume. In PFR initially the rate of the reaction is very fast but as the reaction progresses the rate of the reaction decreases but since rate is fast initially it requires small volume than CSTR.
What specifically causes a CSTR in series to have a higher conversion than a CSTR in parallel?
What specifically causes a CSTR in series to have a higher conversion than a CSTR in parallel? When say two CSTRs are in series, the first operates at a higher concentration, therefore the rate is greater, therefore the conversion is greater. The second reactor in series builds on the conversion in the first reactor.
How does a PFR work?
Fluid going through a plug flow reactor is modeled as flowing through the reactor as a series of infinitely thin coherent “plugs”, each having a uniform composition. As the plug flows down the PFR, the residence time of the plug element is derived from its position in the reactor.
What is PFR and CSTR?
CSTR and PFR Holding-Time Ratio versus Conversion for Various Reaction Orders. (CSTR and PFR stand for Continuous Stirred-Tank Reactor and Plug Flow Reactor.) For zero-order kinetics, this ratio is always equal to one and is independent of conversion.
What are some characteristics of the CSTR reactor?
| Type of Reactor | Characteristics |
|---|---|
| Continuously Stirred Tank Reactor (CSTR) | Run at steady state with continuous flow of reactants and products; the feed assumes a uniform composition throughout the reactor, exit stream has the same composition as in the tank |
How does CSTR work?
Continuous stirred-tank reactors (CSTRs) are open systems, where material is free to enter or exit the system, that operate on a steady-state basis, where the conditions in the reactor don’t change with time. Reactants are continuously introduced into the reactor, while products are continuously removed.
How can conversion reactors be increased?
- An increase in the feed temperature will increase the conversion.
- A decrease in feed temperature will increase the conversion.
- There could be a very very very large heat exchanger attached to the reactor with the heat flow given by.
Why conversion is higher in the plug flow reactor?
Rate of reaction is directly proportional to reactant concentration for positive order reactions. More the concentration more will be the rate. Hence PFR gives higher conversion than CSTR for positive order reactions. For same volume of reactor, PFR gives higher conversion compared to CSTR for Positive order reaction.
What are the advantages and disadvantages of batch reactor?
The batch reactor has the advantage of high conversions that can be obtained by leaving the reactant in the reactor for long periods of time, but it also has the disadvantages of high labor costs per batch, the variability of products from batch to batch, and the difficulty of large-scale production (see Professional …