In an absorber, a gas mixture is contacted with a liquid under conditions such that one or more species in the gas dissolve in the liquid. A stripper also involves a gas contacting a liquid, but under conditions such that one or more components of the feed liquid come out of solution and exit in the gas leaving the tower. A process consisting of an absorption tower and a stripping tower is used to separate the components of a gas containing 25.0 mole\% carbon dioxide and the balance methane. A stream of this gas is fed to the bottom of the absorber. A liquid containing 0.450 mole\% dissolved CO2 and the balance methanol is recyded from the bottom of the stripper and fed to the top of the absorber. The product gas leaving the top of the absorber contains 0.98mole%CO2 and essentially all of the methane fed to the unit. The CO2 rich liquid solvent leaving the bottom of the absorber is fed to the top of the stripper and a stream of nitrogen gas is fed to the bottom. Ninety percent of the CO2 in the liquid feed to the stripper comes out of solution in the column, and the nitrogen/ CO2 stream leaving the column passes out to the atmosphere through a stack. The liquid stream leaving the stripping tower is the 0.450%CO2 solution recycled to the absorber. The absorber operates at temperature T2 and pressure P2 and the stripper operates at T5 and P3. Methanol may be assumed to be nonvolatile-that is, none enters the vapor phase in either column - and N2 may be assumed insoluble in methanol. (a) In your own words, explain the overall objective of this two-unit process and the functions of the absorber and stripper in the process. (b) The streams fed to the tops of each tower have something in common, as do the streams fed to the bottoms of each tower. What are these commonalities and what is the probable reason for them? (c) Taking a basis of Nmol/h of gas fed to the absorber, draw and label a flowchart of the process. For the stripper outiet gas, label the component molar flow rates rather than the total flow rate and mole fractions. (d) Use a table format to perform the degree-of-freedom analysis and write in order the equations you would solve to determine all unknown stream variables except the nitrogen flow rate entering and leaving the stripper. Circle the variable(s) for which you would solve each equation (or set of simultaneous equations), but don't do any of the calculations yet