This example is typical of a model developed for preliminaryprocess flowsheet evaluation.§ Fresh benzene and make-up hydrogen are mixed with recycle hydrogen and recycle cyclohexane from the process and fed to a fixed-bed catalytic reactor. In the reactor, thereaction is C6H6 + 3 H2 C6H12 The heat released from this highly exothermic reaction is removed by boiling water outside tubes containing the catalyst pellets. The reactor effluent is cooled andseparated into liquid and vapor phases. The liquid phase is fed to a distillation column to remove the dissolved light ends and to stabilize the liquid product. Part of the liquid from the separator isrecycled to the reactor to aid in temperature control. Once a flowsheet simulation model of the process is developed, it can be used to investigate the effect of the cyclohexane recycle rate on the heatload from the reactor. We can also study the effect of the purge rate on the buildup of inert components in the system. For now, you just need to put the flowsheet together. Use the Redlich-Kwong-Soave(RK-SOAVE) property method in the simulation. The input data are listed as follows:
The description here is taken verbatim from an old Aspen Manual. When you write a report, you need to make adecision if the description should include explicitly the unit and stream labels. Roughly, we do not if we are just making a general conception description. Otherwise, we do if we are writing a technicaldescription of the process and how it is designed.
Composition (Mole Percent) Hydrogen Nitrogen Methane Benzene Flow rate (lb-mol/h) Temperature (°F) Pressure (psia) FreshBenzene 100.0 100 100 15 Make-up Hydrogen 97.5 0.5 2.0 300 (estimate*) 120 335
* The flow of make-up hydrogen should be set to obtain a mole ratio of
hydrogen to benzene equal to 3.3 in the feed to...