NGC8206 Chromatograph

This manual is written to provide an experienced chromatography technician with the requirements necessary to install, setup and operate the Totalflow® Model NGC8206 Natural Gas Chromatograph.

This chapter introduces the user to the Totalflow® Model NGC8206 Series Natural Gas Chromatograph (NGC). The NGC is designed to continually analyze natural gas streams, on-site, determine composition, calorific value and store the analysis information. It is designed for natural gas streams, 800 to 1500 Btu/scf (29.8 to 55.9 Megajoules/meter3) with less than 100 PPM H2S. The unit is a fully functional gas chromatograph for “pipeline quality” natural gas and is designed to analyze natural gas streams, dry of both hydrocarbon liquids and water. The unit can collect and retain analysis information for one to four independent sample streams. Applicable installations include: Transmission, Distribution, Custody Transfer with Metrology quality results, Production, Gas Gathering and End User Gas Markets.

Based on ABB Totalflow XSeries technology, the NGC features a common platform that combines the expandable framework of the XSeries equipment with the capabilities of a remote gas chromatograph. This expandability allows the NGC to run other applications such as AGA-3 and AGA-7, while simultaneously doing stream analysis. This new platform is designed for operation on Windows CE Real Time Operating System.

Once installed on the meter run, the unit can immediately calculate the calorific value of natural gas. The user can utilize their own calibration blend to adjust the unit to their company’s standards or take advantage of various automatic operational features by using the recommended calibration

A natural gas sample is extracted from the pipeline, processed for particulate removal and phase integrity by the sample conditioning module (optional as required), transported to the NGC and injected onto the chromatographic columns where component separation occurs. The NGC analyzes each sample, utilizing established chromatographic techniques. The resulting information consists of mole percent values for each component. These values are used to perform energy calculations. Calculated values include: gas compressibility, real relative density, Btu/CV value, liquid GPM, wobbe index, methane number and several other optional calculated values. Gas compressibility selections include NX-19, AGA-8 detail, single virial summation factor, ISO summation factor and none (a factor of one is used). The processed sample is then vented with the carrier gas and results are stored in memory and communicated to other devices, as needed. All of these values as well as composition are available on various Modbus communication protocols. gas.

To further define the natural gas components, Table 1–1 gives additional details for each hydrocarbon. Among the key information is the boiling point of the component. The boiling point of each component correlates to the order each component will exit the column.