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.
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.