A natural gas vehicle (NGV) cylinder with a volume of 55 liter is kept in a room at 30 C. An engineer has used the ideal gas equation of state (EOS) to determine that if the tank is first evacuated and then charged with 10 kg of pure methane, its rated maximum allowable working pressure (MAWP) will be attained. Operation at pressures above this value is considered unsafe. (a) (b) What is the maximum allowable working pressure (atm) of the cylinder? (5 Marks) You suspect that at the conditions of the fully charged tank, ideal gas behaviour may not be a good assumption. Use the Redlich-Kwong equation of state (RK-EOS) to obtain a better estimate of the MAWP value. (12 Marks) Compare the MAWP values obtained from questions (a) and (b). Is the difference significant? Which the equation of state (EOS) is preferred to determine the MAWP from safe handling of flammable gas. Justify your answer. (8 Marks) (c)