Why is CSTR larger than PFR?

CSTR reduces concentration of reactant to minimum in less time than what PFR does. 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.

What is residence time in CSTR?

The residence time (RT) in minutes is the time it takes to entirely exchange the volume of the reactor and is expressed as shown above, where V = the volume of the reactor and Q is the flow rate of the effluent leaving the system.

What does residence time depend on?

The Permanence of Carbon Sequestered in Terrestrial Ecosystems. The mean residence time (MRT) of C sequestered in soil and biota depends on numerous factors, including land use, management system, soil type, vegetation, and climate. The MRT is computed as a ratio of the pool (Mg ha− 1) to the flux (Mg/ha/year).

Which has higher conversion PFR or CSTR?

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 is better CSTR or PFR?

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 residence time important?

The residence time is effectively the average length of time that an entity, in this case a water molecule, will remain in a reservoir. It is really only meaningful for a reservoir that is at or near a steady state condition.

Is residence time and space time the same?

The residence time(t) and space time(tau) are not exactly the same. space time is the time required to process the one reactor volume of feed and the residence time is the amount of time spent by a particle until it exits the reactor.