Final answer:
Continuous Stirred Tank Reactors (CSTR) require a larger volume than Plug Flow Reactors (PFR) due to differences in flow patterns and mixing characteristics.
Step-by-step explanation:
The reason Continuous Stirred Tank Reactors (CSTR) require a larger volume than Plug Flow Reactors (PFR) is because of the different flow patterns and mixing characteristics in each reactor type.
In a CSTR, the reactor contents are continuously mixed, resulting in a uniform distribution of reactants and products throughout the reactor. This means that reaction rates remain relatively constant throughout the reactor, which requires a larger volume to achieve the desired conversion.
On the other hand, in a PFR, reactants are continuously fed at one end of the reactor and products are withdrawn at the other end. This results in a gradient of reactant concentration along the reactor length, and the reaction rates vary as a function of position. Since the reaction is more concentrated at the front of the reactor, a smaller volume is sufficient to achieve the same conversion as a CSTR.