7. You are tasked with separating a stream containing 30 mole percent ethane and the remainder methane into a product that contains 97 mole percent methane. To accomplish this, you

intend on using distillation and taking advantage of the different relative volatility of the components. The feed stream enters the first column with a flow rate of 100 g mol/min. It is separated into an overhead product containing 90 mole percent methane and a bottoms product containing 98 mole percent ethane. The overhead product from the first column is fed to a second distillation column. The overhead product from this column is the desired product. The bottoms product, which has a flow rate of 100 g mol/min, is recycled back to the first column. a) Sketch the flow sheet for this problem, identifying all streams; b) Calculate the flow rate of the final product; c) Calculate the composition of the recycled stream;