Certified mass-based measurement system for marine bunkering

Emerson introduces Micro Motion solution with high measurement accuracy and traceability with third-party certification.

06/14/2011


EmEmerson Process Micro Motionerson’s Micro Motion Certified Marine Bunker Measurement Solution is the first traceable, transparent, mass-based measurement system with third-party certification for heavy fuel oil (HFO) bunkering. Installed on a vessel, barge, or at a terminal, this system monitors the bunker delivery, reports final totals, and provides a ticket that can be used for custody transfer. The company says this globally-certified bunker custody transfer system meets international standards and provides highly accurate, transparent bunker fuel deliveries that will minimize the number of disputes between barge operators and ship operators, while enabling operators to very accurately monitor fuel and improve operational efficiencies.

Emerson points out that while bunker transfers are billed based on mass, measurements are calculated using volumetric-based methods. Traditional bunker measurement relies heavily on look-up tables and manual dips, as well as laboratory tests to determine density measurements. The practices are labor intensive, inferential, and can result in legal disputes and potential reputation damage. With bunker fuel costs amounting to 50-70% of the total ship operating expense, even small inaccuracies can have a major effect on operating costs.

The system includes a Micro Motion Elite Coriolis flowmeter, Series 3000 transmitter with Marine Bunker Transfer Package, and bunker delivery ticket printer. The solution is capable of handling the density and viscosity variation inherent in HFO and was certified by Nederlands Meetinstituut (NMi), the notified body for testing to the guidelines of the European Instruments Directive (MID) and issuing authority for OIML (International Organization for Legal Metrology). The Micro Motion meter meets the OIML standard R117-1 and the overall solution meets MID standard 2004/22/EC Annex MI-005.

The process of marine bunkering presents challenges to any measurement device. Unlike gasoline or diesel fuel, the density and viscosity of HFO varies enormously and can even vary across a single bunkering as the fuel may stratify in the storage tank. This means that measurement systems based on volume need a correction factor applied to determine the mass of the fuel that has been delivered. In addition, the fuel being delivered can become aerated, which will affect the volume measurement.

Micro Motion Coriolis flowmeters deliver consistent, accurate mass measurement. The Certified Marine Bunker Measurement System has been specifically designed to handle high-viscosity, aerated liquids and offers an overall accuracy within ±0.5% of mass. The transmitter post alerts when the level of entrained air reaches a pre-set limit, allowing the operator to take steps to reduce aeration and ensure accurate delivery. A printed bunker transfer receipt includes the time, date, and the total quantity transferred, and can be used as a legal (Weights & Measures) document.

Micro Motion Elite high-capacity meters are capable of handling flow rates over 1,500 tons/h and delivers reliable performance. They have been tested with crude oil and other liquid and gas hydrocarbons in accordance with American Petroleum Institute (API) and American Gas Association (AGA) guidelines.

www.emersonprocess.com

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- Edited by Peter Welander, pwelander(at)cfemedia.com, Control Engineering, www.controleng.com