A simple ChemCAD (version 6) tutorial

Consider a methane/octane feed stream with the following properties
Temperature:23oC
Pressure:101350 Pa
Composition:10 mole% methane, 90 mole% n-octane
Flow rate:1000 kmol/hr

and a nonadiabatic flash drum operated under the following conditions
Temperature:85oC
Pressure:101350 Pa

ChemCAD demo design procedure

  1. Start the ChemCAD application.
  2. Select one Feed (right arrow on the main pallet) and two Product (the other right arrow) symbols; a single mouse click selects the icon.
  3. Select Flash #1 with a single click; place unit on canvas.
  4. Clicking on the Connector icon in the main pallet, connect Feed symbol to the Flash Drum inlet stream, and the Product symbols to the flash outlets. On the Flash Unit icon, blue dots represent equipment feed streams and red dots represent equipment outlet streams.
  5. File -> Save the flow sheet to the desktop; a temp folder will be created into which the final report will be placed.
  6. Choose menu item Format -> Engineering Units to select SI units for this problem; stream compositions (component flows) should be in terms of molar flowrates. After making these choices, click OK.
  7. Select Thermophysical -> Select Component and select methane and n-octane to save to this component list.
  8. Select default values for the thermodynamics wizard.
  9. Select the input stream and left-double click on the stream number box to obtain Edit Stream menu.
  10. Enter feed stream flow rate, temperature (in K!), pressure, and composition.
  11. Double (left) click on flash unit and select Flash Mode = 2; enter flash drum operating temperature and pressure.
  12. From the main menu, select Run -> Run All; correct errors, if any.
  13. From the solution report obtained from Output -> Consolidated Report and then clicking on the Calculate and Give Results button, determine flash drum vapor and liquid stream compositions, molar flowrates, K-values, and flash drum heat duty.