Question 1 2 You extract a sample of subsea clathrate, that was solid under very high pressure, and bring it to ambient temperature and pressure. A two-phase vapor-liquid mixture consisting of water (H2O), methane (CH4), ethane (C2H6), propane (C3H8) carbon dioxide (CO2), and hydrogen sulfide (H2S) is formed. Using Gibbs Phase Rule, calculate the number of internal degrees of freedom for this system. If the temperature, pressure, and liquid phase composition of hydrogen sulfide are pre-set by process conditions and waste standards, how many more parameters can you control before the system becomes completely determined? (3 pts) Question 2 The first step in processing is sulfur removal, an important step to prevent corrosion of process equipment. Before designing hydrodesulfurization units, you want to verify whether less expensive processes, such as single stage flash, can be used to remove H2S. You estimate the feed characteristics of subsea clathrate to be (pure vapor at ambient T and high P): Component H20 CH4 C2H6 C3H8 Label 1 2 3 4 5 Flow rate (kmol/h) 25 55 20 5 10 5 K-value 0.25 4,000 3,500 3,000 1.50 0.20 CO2 H2S 6 Determine whether an isothermal flash stage can remove 99.9% of H2S as part of the liquid exit stream. Show all the steps. How much methane is lost in the liquid exit stream? If the unit cannot reach desired specifications, suggest at least one way (and explain why) in which the isothermal flash process can be modified to enhance H2S mole fraction in the liquid stream. (7 pts)