For the following simulation problems, consult Table 7.2 and list the design decision variables.

(a) An equimolar mixture of benzene and toluene in a process stream is in the liquid state at \(300 \mathrm{~K}\) and \(1 \mathrm{~atm}\). If a heat exchanger is employed to totally vaporize this stream, indicate which unit module should be used, which design variables need to be specified, and which variables will be calculated.

(b) Consider an equimolar mixture of ethanol and water at \(300 \mathrm{~K}\) and \(1 \mathrm{~atm}\). In a distillation column, indicate the design variables to be specified to obtain \(95 \mathrm{~mol} \%\) of the ethanol-water azeotrope as the distillate and \(99 \mathrm{~mol} \%\) water as the bottom product. Can the distillate product be \(99 \%\) ethanol?

(c) The reactor effluent from a superheated vapor needs to be separated into a vapor stream for vapor recovery and a liquid stream for a liquid recovery. Indicate which unit modules need to be employed for only mass-balance calculations and how either the temperature and/or pressure will be specified for the vapor-liquid separation operation and for rigorous simulation.

(d) From the following mixture (ethylene \(=3,681.9 \mathrm{kmol} / \mathrm{hr}\); propylene \(=363.8 \mathrm{kmol} / \mathrm{hr}\); methane \(=368.2 \mathrm{kmol} / \mathrm{hr}\); diethyl ether \(=\) \(6.6 \mathrm{kmol} / \mathrm{hr}\); water \(=2,417 \mathrm{kmol} / \mathrm{hr}\), and ethanol \(=282.8 \mathrm{kmol} / \mathrm{hr}\); at \(550 \mathrm{~K}\) and \(60 \mathrm{~atm}\) ), \(50 \%\) of diethyl ether is to be removed as a liquid product in a PT-flash operation. What should be the temperature and pressure of the PT-flash operation? What will be the distribution of products as overhead vapor and bottom liquid products? If from the overhead vapor product ethanol and diethyl ether are to be recovered through an absorption column with water as the solvent, list the variables that need to be specified and the variables that will be calculated through simulation of an absorption column.

Table 7.2:-

Table 7.2 Rigorous Models of Unit Operations Unit Module Simple (one stream) heater or cooler (temperature changer) ASPEN PLUS Heater (thermal and phase state changer; models heater, cooler, condenser, and so forth; specify feed stream, temperature, pressure) PRO/II Simple heat exchanger (thermal and phase state changer; models heater, cooler, condenser, and so forth; specify feed stream, temperature, pressure) Shell-and-tube heat exchanger UniSim Design Cooler Heater www wwwww LNG exchanger (feed stream, duty, outlet temperature Pump (pressure changer) HeatX Rigorous heat exchanger (two stream heat exchanger; models cocurrent (two stream heat exchanger; models and countercurrent shell-and-tube heat exchanger; process fluid, specify service fluid, exchanger specification) Pump (feed stream, discharge pressure, duty) cocurrent and countercurrent shell-and-tube heat exchanger; specify process fluid, service fluid, exchanger specification) Pump (feed stream, discharge pressure, duty) Heat exchanger (tube side inlet and outlet, shell side inlet and outlet) Pump (feed stream, discharge pressure, duty)