Tubular Reactor Simulation Using Aspen Plus

For the expensive catalyst, the optimum steady-state design has a TAC of 1.57 x 106 per year. The reactor has 190 tubes, 0.111 m in diameter and 8.51 m in length, containing a total weight of catalyst of 31,380 kg. The inlet (and steam temperature) is 477.3 K. The recycle flowrate is 0.38 kmol/s. The ra/ rb ratio is 1.017. 

It is important to note that the heat transfer coefficient U in the expensive catalyst case is almost twice that in the cheap catalyst case. This is due to the larger recycle flowrate and higher velocity in the tubes. The heat transfer areas AR of the two designs are only 20% different because the inlet temperature of the expensive catalyst design is higher, which provides less temperature differential. The UAR product has an important effect on the dynamic controllability of this system, which will be studied in Chapter 6. 

8 TUBULAR REACTOR SIMULATION USING ASPEN PLUS 

Tubular reactors can be simulated using Aspen Plus. Several configurations are available constant-temperature reactor, adiabatic reactor, reactor with constant coolant temperature, reactor with countercurrent flow of coolant, and reactor with co-current flow of coolant. The isothermal reactor cannot be exported into Aspen Dynamics because it is not possible to dynamically control the temperature at all axial positions. Therefore only the last four types will be discussed. 

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