New GC Solution for a fast analysis of refinery gases

Refinery gas is typically consumed as a fuel gas. As refinery gas is a mixture of the lightest hydrocarbon streams generated during refinery processes, it is essential to determine its composition. Da Vinci Laboratory Solutions (DVLS) developed a new GC solution for the fast analysis of refinery gases. In only 9 minutes the DVLS Fast Refinery Gas Analyser (RGA) characterises the hydrocarbon content, permanent gases and Hydrogen Sulfide in refinery & liquefied gases.

Fast analysis of refinery gases

The DVLS RGA solution is based upon the Agilent 7890B GC configured with three different channels, dedicated columns, valves, an inlet and three detectors. The multi-channel configuration of the RGA allows to inject the gas samples into the separate channels at the same time:

• the FID Channel determines C1-C5 and C6+ group
• the Back TCD Channel separates Oxygen/Argon, Nitrogen, Carbon Monoxide, Carbon Dioxide and Hydrogen Sulfide
• the Aux TCD Channel determines Helium and Hydrogen

The hydrocarbon components in the sample are transferred to a split injector, separated by a PLOT column and detected by an FID. All permanent gases except Hydrogen are separated onto a combination of (micro) packed columns. Hydrogen is determined on the second TCD channel. All channels operate simultaneously to provide a fast gas analysis in less than 9 minutes.

The RGA is designed with a unique side carrier with heated zones (as displayed in Figure Two) that contains the valves and columns. This unique design reduces the system downtime during the periodical regeneration of the separation column.

Representative Injection of Liquefied Gases

For a representative analysis of LPG or other gases which are liquid under pressure, the sample must remain in the liquid phase during the injection process. To maintain a liquid sample in a liquid phase under constant pressure during the injection Da Vinci developed a Pressure Station. Add the Pressure Station, a Gas Sampling Valve and/or Liquid Sampling Valve to the RGA configuration and the GC solution could also be used to analyse liquefied gases.

Standard Methods Compliance

The Refinery Gas Analyser complies with the various standard test methods to determine the composition of the refinery & liquefied gases:

• ASTM D1946 (inert gases only), D2163, D2504, D2593, D4424 and D7833
• DIN51666
• EN 15984
• IP 405
• ISO 7941, EN27941
• UOP539

Automated Reporting of Gas Properties

The GC is controlled by Agilent OpenLab software. The DVLS PetroReporter software (as displayed in Figure 3) automates all aspects of the calibration, gas analysis through reporting of gas calculations such as:

• Carbon content
• Emission factor
• Gas calculations as specified in ASTM D2598, D3588, EN 589 and ISO 8973
• Heating Value, Calorific Value and BTU
• Liquid volume
• Molar mass
• Relative Density
• Real specific gravity
• Vapor pressure
• Oxygen correction (optional)
• Customised calculations (optional)

The DVLS PetroReporter is compatible with chromatographic data systems (CDS) of major suppliers including the new OpenLab 2.x (Client-server). PetroReporter can be used either stand-alone or in a network configuration. Contact Da Vinci Laboratory Solutions for more information.