Consider a binary equimolar mixture of acetone and chloroform at \(300 \mathrm{~K}\) and \(1 \mathrm{~atm}\). Because this mixture forms a binary azeotrope, methyl- \(n\)-pentyl ether solvent is used to extract the chloroform from acetone. The flowsheet in Figure 7.40 for the process shows the results of solving a simple mass-balance model. Perform a rigorous simulation of the process by converting the two component-splitter modules into distillation-column modules. This involves finding appropriate specifications for the two distillation columns to yield approximately the mass balance given in the flowsheet. Assume a pressure of \(1 \mathrm{~atm}\) in all streams and estimate the temperatures of the other streams according to their phases (saturated liquid or vapor).

The separation in the mass-balance flowsheet gives an acetone product of approximately \(96 \%\) purity from column 1 and a chloroform product of approximately \(96 \%\) purity from column 2 . A makeup of \(0.8 \mathrm{kmol} / \mathrm{hr}\) of solvent is added to replace this amount lost from the purge stream. How can the product purity be improved and the solvent loss decreased?

Figure 7.40:-

Transcribed Image Text:

Acetone Solvent 0.8 kmol/h T=300 K P=1 atm Acetone 96.95 kmol/h Chloroform 3.05 kmol/h 0.01 kmol/h Solvent P=1 atm Acetone 3.06 kmol/h Chloroform 396.94 kmol/h Solvent 0.00 kmol/h P=1 atm Mixer 100 kmol/h Column 1 Column 2 Chloroform = 100 kmol/h T=300 K P=1 atm Figure 7.40 Simulation results using a simple mass-balance model. Purge Solvent 0.79 kmol/h P=1 atm