Natural Gas Reporter
A custom report program for characterizing natural gas and its condensates.
Chromperfect Natural Gas Reporter estimates two values of importance to the
industry: the heating value of gases, and the Reid vapor pressure of liquids.
Natural Gas
Reporter
The heating value report displays the mole % for each component, the
estimated specific gravity (relative density) of the gas sample, its
BTU/FT3 values, and its Wobbe index, calculated for several conditions:
ideal and real, dry and wet.
The heating value method is compatible with both the three-column
and the single-column back-flushed systems described in Ref 1, and
may be used with either one or two detectors. The formulas and
physical constants were taken from Ref 2.
The Reid vapor pressure calculation follows, or rather emulates, the
standard laboratory method, as codified in ASTM D323-56 (1958). Also
calculated are. The algorithm is loosely based on previously published
work. (Ref. 6) However, we do not use the Rachford-Rice equation.
The Reid vapor pressure report displays the RVP value, the mole % for
each component in the liquid and the gas phase, the fraction volatilized,
and the average molecular weights of the two phases at equilibrium,
and of the original sample.
The Natural Gas Reporter is controlled by a configuration file which is
editable by the end user. This file contains the component names and
the associated physical constants, as well as other settings to be
described. As supplied, the configuration file lists seventeen
components of natural gas, both hydrocarbon components (the normal
alkanes, methane through dodecane, and the branched alkanes, iso-
butane and iso-pentane) and inactive components (nitrogen, oxygen,
and carbon dioxide). This list may be adjusted to match the resolution
of the chromatograph.
The Natural Gas Reporter operates in one of two modes, monitor mode
and user program mode. In monitor mode, the Natural Gas Reporter
monitors a specified directory and notices the arrival of files of a
specified extension. As these files arrive, they are opened, read, and
processed, and the resulting report is put in an ASCII file, which is
created in the same directory as the input file. The report file has the
same name as the input file, but the extension is changed.
In user program mode, the Natural Gas Reporter expects to be
launched as a Chromperfect user program. The source file is a ZED file
based on a Format file and created by the Chromperfect program,
Traffic. This one file is processed in the usual way, and the program
terminates. There is an alternate version of Natural Gas Reporter which
generates the identical report, but sends it to the printer, or to a PDF
file. The configured output file extension is ignored. In all other aspects,
they are identical.
An Example Report
Input file name
C:\CPData\JunkRawFiles\NatGasStd.2.txt
Name
Mole %
Normalized Mole %
Gallons/1000CF
C1
63.000
63.000
6.161
C2
9.000
9.000
1.375
C3
6.000
6.000
1.344
C4
3.000
3.000
0.886
iC4
3.000
3.000
0.886
C5
1.000
1.000
0.354
iC5
1.000
1.000
0.355
C6
1.000
1.000
0.401
C7
1.000
1.000
0.449
C8
1.000
1.000
0.498
C9
1.000
1.000
0.548
C10
1.000
1.000
0.597
C11
1.000
1.000
0.644
C12
1.000
1.000
0.665
N2
5.000
5.000
0.427
O2
1.000
1.000
0.085
CO2
1.000
1.000
0.147
Total Mole %
100.000
PASS
BTU/CF at 14.65 PSI
Ideal, Dry
1,708.03
Ideal, Wet
1,678.14
Real, Dry
1,723.07
Real, Wet
1,692.92
Specific Gravity
Ideal
1.089
Real
1.098
Z for sample
0.99127
Z for air
0.99963
WOBBE Index
Ideal, Dry
1,637.09
Ideal, Wet
1,608.45
Real, Dry
1,651.50
Real, Wet
1,622.60
Reid vapor Pressure
934.08
Mass % in liquid phase
54.550
Mass % in gas phase
45.450
Calculated sample density
0.607
Z for gas phase
0.79763
AdjVolumeRatio
3.94
SampleVolG
233.29