The effluent gas from a refinery with a composition 83 mol % CH4, 6 mol % C2H6, 7 mol % C3H8 and 4 mol % n-C4H10 is fed into an absorber to reduce the propane content of  the effluent before recycling. The absorber is operated at 40°C and 500 kPa and 80% of the C3H8 (propane) must be removed. Lean oil is used in the absorber to remove propane and contains 0.5 mol% C4H10 but none of the other lighter compounds. The  absorber has 9 theoretical stages and the molar ratio of the entering oil to entering gas is 2. The k-value has shown in Table 1. Table 1: K- values are as follows: Assessment 03 (Major Test 01) 2.1. Determine the compositions of the gas and liquid streams leaving the absorber.(17) 2.2. What is total flow for both the liquid and gas out? (2) [19 marks] 

This is Separations Principles on Gas Absorption