At the petrol pump, the fuels are accurately metered to ensure that you get the amount of fuel that you pay for. Thinking on behalf of the oil company, they deliver the right amount of fuel for the money they receive. Precise measurement makes sense for both parties. The same can be said for LNG metering.
The monthly value of Asia’s LNG imports is regularly more than US$10 billion. With such vast sums of money changing hands, the importance of accurate metering of the LNG is clear. The gas analyzers used in this application are process gas chromatographs which measure the heating value of the LNG as it is transferred from the production stations to LNG tankers. But these are not delicate laboratory instruments, they are rugged and robust devices capable of withstanding harsh environmental conditions.
This is not the highly controlled laboratory environment of bench-mounted gas chromatographs, it’s the high seas. The ABB NGC8200 series of process gas chromatographs can withstand ambient temperatures from -18 °C to +55 °C. Furthermore, with Class 1, Division 1 explosion-proof rating, they are suitable for LNG tanker and FLNG applications.
When it comes to accuracy, modern process GC’s can match many of their laboratory-based cousins. The requirement for a Class A device is an accuracy of plus or minus 0.5% and the accuracy of the NGC8200 series can be 0.1% which surpasses these requirements by a factor of 5. Measurement accuracy is a big deal – every cent counts when trading these precious natural resources.