Radfrac module

The simulation is performed with the Radfrac module in ASPEN Plus and the NRTL liquid-activity model [20]. Tracing the RCM (Figure 3.15) shows that acetone and chloroform are unstable nodes, toluene is a stable node and the maximum-boiling azeotrope acetone-chloroform is a saddle. The distillation boundary shows a strong curvature. 

Once the dominant design variables are idOTlified, a systematic design procedure can be devised for aU three flowsheets. All of the simulations were carried out using Aspen Plus with the RadFrac module provided with Fortran subroutines for the reaction rates. For a system with a given production rate and product specifications, the design steps are the following ... 

Process simulation units (that is, blocks, modules, or subroutines) are mapped into more descriptive models of process equipment (e.g., mapping a HEATX simulation unit into a floating-head, shell-and-tube heat exchanger mapping a RADFRAC simulation unit into a tray tower, complete with reboiler, condenser, reflux accumulator, etc.) and associated plant bulks, which include installation items, such as piping, instrumentation, insulation, paint, etc. 

---