CWOUT CONDENSE PREHEAT S10 COLFEED OVHD OUTPH CWIN FEED SEP OUTCOND COLUMN VENT LSEP RDRUM TO COLUMN B R S1 TOTAL Figure 6. Aspen Plus process flow diagram.

explain the flow diagram based on the feed run

Extracted text: CWOUT CONDENSE PREHEAT S10 COLFEED OVHD OUTPH CWIN FEED SEP OUTCOND COLUMN VENT LSEP RDRUM TO COLUMN B R S1 TOTAL Figure 6. Aspen Plus process flow diagram.


Extracted text: Figure 5. Temperature profiles; total reflux; simulation and experimental. An Aspen Plus simula- tion is developed to model the process. An Aspen "Radfrac stripper" model (reboiler but no condenser) is used for the column. Aspen "HeatX" models Feed run The experimental values that were specified for input data are used for the feed preheater and condensers. The NRTL physical property package is used. The process flow diagram is given in Figure 6. to the simulation are listed below. 1. Adjusted feed flowrate = 1.631 kmol/h 138 Chemical Engineering Education 2. Adjusted feed composition = 0.2191 mole fraction methanol 6. Cooling water flowrate = 0.433 kg/min 7. Cooling water inlet temperature = 5.8 °C 3. Feed tank temperature = 20°C 8. Partial reboiler stage efficiency = 100% 4. Bottoms flowrate = 1.286 kmol/h 9. Stage efficiency 65% 5. Reflux flowrate = 0.464 kmol/h All of the other variables are calculated by the model. Table 4 compares experimental and simulation results. The agreement is quite good. Figure 3 com- pares the temperature profiles. Table 4 Comparison of experimental and simulation results; feed run Experiment Simulation Total reflux run mf methanol 0.965 0.956 How to set up a total reflux simulation is not completely obvious. The Aspen Plus "Radfrac" model requires feed and product streams, but these are all zero under total reflux operation. The reflux flowrate is set at the experimental value (0.8343 kmol/h). Efficiency is set at 65%. mf methanol 0.022 0.021 QPH kW 1.473 1.547 Qew kW 5.938 6.797 kW 16.40 9.404 Tovhd °C 66.3 65.8 A small feed flowrate (0.01 kmol/h) is specified with composition 0.211 mole fraction Treflux °C 50.6 46.9