Benzene is a chemical product with multiple applications; however, due to safety issues it has been replaced by cyclohexane, which has very similar physicochemical properties. Cyclohexane is produced by catalytic hydrogenation of benzene in a reactor. The molar flow rate of benzene entering the reactor is 100kmol/h and the conversion of benzene to cyclohexane is 52%. The final application requires cyclohexane with purity above 90%, thus a separator is required to purify the reactor effluent. Main properties of these 2 components are shown is table 1. 1. An approach possible to separate cyclohexane from benzene is using liquid-liquid extraction followed by distillation. Why can't cyclohexane be separated from benzene using distillation alone? Will this sequence of mass transfer operations work? Why? 2. Three solvent are available for LLE (see Table 2). Which solvent do you select for cyclohexane removal? Why? 3. Using your chosen solvent from Q2 and considering a mixture containing 40% cyclohexane, estimate the number of stages required for liquid-liquid extraction of the reactor effluent to obtain an extract with 60% of cyclohexane. Show a well-labelled diagram and clearly stated mass balances over the unit. Calculate the molar flow rates and compositions of fresh solvent, extract and raffinate. 4. Extract obtained from liquid-liquid extraction process is then feed to a distillation column operating at 1 atmosphere. Estimate the number of stages for distillation taking in account that the column operates at a reflux ratio of 2 . Identify the optimum feed-stage location in the distillation column. Show a well-labelled diagram and clearly stated mass balances over the unit. Calculate molar flow rate of distillate and bottom products. What is the overall yield of cyclohexane across the entire process. Table 1 - main properties of benzene and cyclohexane. Table 2 - main properties of various solvents