Use a generalized fugacity chart Fig A6 Fundamentals of Engi
Solution
a)
For Butane, critical pressure = 38 bar , critical temperature = 425.1 K
At 150 bar, Reduced pressure = 150 / 38 = 3.947
At 555 K, reduced temperature = 555 / 425.1 = 1.306
From generalized fugacity chart, At Pr = 3.947 and Tr = 1.306, we get Fugacity coeff f/p = 0.61
Hence, Fugacity f = 0.61*150 = 91.5 bar = 90.3 atm
b)
For Methane, critical pressure = 46 bar = 667.17 psi , critical temperature = 190.6 K = -116.6 F = 343 deg R
At 800 psi, reduced pressure = 800 / 667.17 = 1.199
At 120 deg F = 580 deg R, reduced temperature = 580 / 343 = 1.691
From generalized fugacity chart, At Pr = 1.199 and Tr = 1.691, we get Fugacity coeff f/p = 0.95
Hence, Fugacity f = 0.95*800 = 760 psi = 51.7 atm
c)
For Benzene, critical pressure = 49 bar = 48.36 atm, critical temperature = 562 K = 551.93 F = 1011.6 deg R
At 135 atm, reduced pressure = 135 / 48.36 = 2.791
At 890 deg R, reduced temperature = 890 / 1011.6 = 0.88
From generalized fugacity chart, At Pr = 2.791 and Tr = 0.88, we get Fugacity coeff f/p = 0.18
Hence, fugacity f = 0.18*135 = 24.3 atm
