Question 1 [50]

1. A process solution composed of 65 mass % ethanol (C₂H₅-OH), 9 mass % methanol (CH₃-OH), and the balance water (H₂O) is fed into a separator at a rate of 250 kg/hr. Two outlet streams exit the separator in a continuous process. One stream exiting the separator flows at the rate of 75 kg/hr with a composition of 85 mass % ethanol (C₂H₅-OH), 10 mass % methanol (CH₃-OH) and water (H₂O). The other stream exits the process at unknown flow rate and composition.

1. Draw and completely label a schematic diagram of the process (5 marks)
2. Calculate the flow rate and composition of the other outlet stream (15 marks)

2. Concentrated orange juice is produced using two consecutive evaporators. A fresh feed containing 75 mass % water and orange juice enters the process at a rate of 300 kg/hr where 110 kg/hr of pure water is remove at the first evaporation stage and 90 kg/hr of pure water is evaporated at the second stage. In order to get the required 25 mass % water in the final product, 10 kg/hr of the fresh feed bypass the two evaporation stages to be mixed with the process stream exiting the second evaporation stage. The final product is to contain 25 mass % of water.

1. Draw and completely label a schematic diagram of the process. (10 marks)
2. Calculate all unknown streams flow rates and compositions (mass fractions of components in each streams). (20 marks)
   1. In the combustion process, 350 mol/h of decane (C₁₀H₂₂) is burnt in combustion chamber with 50% excess oxygen. 90% of C₁₀H₂₂ goes into complete combustion, 7% of C₁₀H₂₂ goes to incomplete combustion and the balance remains unburnt.

QUESTION 2 [50]

Perform the analyses of the product gas both on a dry and wet basis. (30 Marks)

1. During testing 50 kg of propane (C₃H₈) is burned with 950 kg of air to produce

150kg CO₂ and 70 kg of CO. What was the percentage excess air? (15 Marks)

1. Write the balanced equation of the complete and incomplete combustion reactions of the following compounds:
   1. C10H22

1. N₂ (5 Marks)