C243 – TP-15 2007 Vapour Pressure Calculation for NGLs

Description

This calculates the equilibrium vapour pressure of natural gas liquids based on their relative density and process temperature.

References

API MPMS 11.2.5/GPA Technical Publication TP-15 – A Simplified Vapor Pressure Correlation for Commercial NGLs September 2007

Kelton calculation reference C243

FLOCALC calculation reference F058

KIMS calculation reference K198

Options

Method

• New
• Modified

Choose option based on which method you wish to employ. The modified method requires the vapour pressure at 100°F as an input.

Constants

Gas coefficients

C = 443°F

D = 543°F

Table 1: Parameters for vapour pressure correlation

Range A0 A1 A2 B0 B1 B2
0.35 ≤ γ60 < 0.45 17.5297 -24.604 24.373 -6567.6 19322 -24693.3
0.45 ≤ γ60 < 0.49 7.9907 7.562 0 1895.5 -10596.9 0
0.49 ≤ γ60 < 0.51 -6.4747 37.083 0 12038 -31296.5 0
0.51 ≤ γ60 < 0.56 11.5454 1.749 0 1378.8 -10396.1 0
0.56 ≤ γ60 < 0.585 6.4827 10.79 0 3721.5 -14579.5 0
0.585 ≤ γ60 < 0.625 6.5412 10.69 0 6514.5 -19353.9 0
0.625 ≤ γ60 ≤ 0.676 20.8537 -12.21 0 -6765.6 1894.3 0

Calculation

Vapour Pressure

The equilibrium vapour pressure is calculated by:

Modified Method

 Where T = Process temperature P100 = Vapour pressure at 100°F A = Coefficient based on Table 1 “Ax” parameters and relative density B = Coefficient based on Table 1 “Bx” parameters and relative density C = Gas coefficient C

Back