Page 101 - PVT Property Correlations

Wet Gases Chapter | 4 79

hydrocarbons. The same procedure explained to calculate heat content for
dry gases is followed to calculate the heat content for wet gases. Sometimes,
gas may be sold before further processing in a gas plant. In this case, it will
usually have higher heat content and be sold for a premium. When gas con-
tains significant amounts of liquids, it may sometimes make economic sense
to process the gas to extract the NGL. The heat content of the two wet gases
presented in this chapter is calculated in the following example.

Problem 3—Calculating Heat Content for Wet Gases
Calculate heat content for the two gases with the composition given above.

Solution of Problem 3
Following the same procedure for calculating the heating value in the Dry
Gases Chapter, Tables 4.9 and 4.10 show the detailed calculations for the
heat content for the two example gases.

TABLE 4.9 Heating Value Calculations for Sample 1
Component Mole % L cj y j 3 L cj z j y j 3 (1 2 z) 0.5
N 2 0.49 0.0 0.000 0.994 0.000370
6.36 0.0 0.000 1.000 0.001102
CO 2
C1 72.79 101.0 73.518 0.998 0.032553
C2 9.28 1769.6 164.219 0.992 0.008352
C3 3.81 2516.1 95.863 0.983 0.005040
i-C4 0.78 3251.9 25.365 0.971 0.001326
n-C4 1.16 3262.3 37.843 0.967 0.002117
i-C5 0.44 4000.9 17.604 0.948 0.001003
n-C5 0.37 4008.9 14.833 0.942 0.000891
C6 1.00 4755.9 47.559 0.910 0.003000
C7 1 3.53 5502.5 194.238 0.852 0.013580
1332.703 0.069334
z 5 0.9952
L c 5 1339