Natural gas from a fracking facility

Natural gas from a fracking facility was estimated to have the
following (molar) composition – 66% methane, 22% ethane and
12 % propane
• In order to design the extraction process, it is important to
understand the properties of the gas mixture. Your bosses ask you
to calculate the fugacity of the components at 75oC. Present your
findings in a report containing the table below:
P (bar) Z
𝒎𝒆𝒕𝒉𝒂𝒏𝒆
௏
𝒆𝒕𝒉𝒂𝒏𝒆
௏
𝒑𝒓𝒐𝒑𝒂𝒏𝒆
௏
5
10
25
Project #2 – due 10/8/21
Submit on Canvas – Excel file titled lastname.xlsx
Answer file (1 page only – assumptions, data used, and results table): lastname.pdf
Peng-Robinson EOS (PREOS)
• Cubic Solver
•
• Where Z = compressibility factor Z = PV/RT
• If it is a pure component
• Given T and P
• Use values of Tc, Pc, κ and ω to calculate a(T) and b
(Table 6.6-1, p. 250)
• Use a and b to calculate A, B (Table 6.4-3)
• Use A, B to calculate α, β and γ
• Solve for Z (careful of multiple roots)
General objective - Given T, P calculate V, H, S (and G)
Z is the compressibility factor
Once you get Z….
• Can get molar volume (V)
• Use Eqn. 6.4-29 to get
• Use Eqn. 6.4-30 to get
• Solve for H and S (see Illustration 6.4-1)
• Solve for fugacity using Eqn. 7.4-14a (if vapor), 7.4-
14b (if liquid)
• Values of a, b, A and B in the equation are the same as
what you calculated
Similar flow chart – Figure 7.5-1
If it is a mixture (your project)
• Calculate pure component a and b
• Calculate the mixture a and b
• Solve for Z using mixture values (Zmix)
• Use this in Equation 9.4-10 (vapor) or 9.4-11 (liquid) to get fugacities for each component in the mixture
or
௠௜௫ ௜ ௝ ௜௝
௖
௝ୀଵ
௖
௜ୀଵ
௠௜௫ ௜ ௜
௖
௜ୀଵ
௜௝ ௝௜ ௜௜ ௝௝ ௜௝
Binary
interaction
parameter
௜௜ and ௜ are pure component values e.g. Table 9.4-1
If not available – use
similar or zero
Once you get f….
• You can calculate the activity co-efficient of
component i in the mixture since:
•Calculate