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PFR are continous type of reactors with high conversion rates, compact in design, opex is less however, temperature in such reactors are controlled critically, which makes temperature control difficult.
Continuous operation, high conversion rate, less cost for operation.
Tempratures are hard to control .
PFR have a high volumetric unit conversion, run for long periods of time without maintainable, and the the heat transfer rate can be optimized by using thinner tubes or fewer thicker tubes in parallel.
Disadvantage of PFR are that temperatures are hard to control and can result in undesirable temperature gradients.
Advantages: Continuous operation, high conversion rate, less cost for operation. Disadvantages: temperature gradients, high maintenance cost
CSTRs (Continuous Stirred Tank Reactor) and PFRs have fundamentally different equations, so the kinetics of the reaction being undertaken will to some extent determine which system should be used. However there are a few general comments that can be made with regards to PFRs compared to other reactor types.
Plug flow reactors have a high volumetric unit conversion, run for long periods of time without maintenance, and the heat transfer rate can be optimized by using more, thinner tubes or fewer, thicker tubes in parallel. Disadvantages of plug flow reactors are that temperatures are hard to control and can result in undesirable temperature gradients. PFR maintenance is also more expensive than CSTR maintenance.
Through a recycle loop a PFR is able to approximate a CSTR in operation. This occurs due to a decrease in the concentration change due to the smaller fraction of the flow determined by the feed; in the limiting case of total recycling, infinite recycle ratio, the PFR perfectly mimics a CSTR.
