“We have already noticed a significant reduction in traditional filter use compared to last year based on 2 months of operation.”
– Darrel Johnson, GM, Menzies Aviation
Hydrocarbon liquids, gasses and refined products often collect significant amounts of black powder contamination (or rouge) in pipeline systems. This black powder contamination consists mainly of iron oxide and iron sulfide compounds; these compounds are typically under 10 microns in size and often in significant quantities down below 1 micron. Unfortunately, it can be costly to clean jet fuel and other refined products with single-use depth media membrane filters.
Issues with black powder in these systems include:
– Degradation of product quality;
– Erosion and abrasion of pipelines that results in black powder contamination;
– Damage to pipeline pump and meter components;
– Costly filter replacement and hazardous waste disposal; and
– Continuous hazard exposure by personnel.
The Nashville airport receives ~80% of its jet fuel from a large US refined products batch pipeline system. Black powder contamination introduced during transportation requires 5-micron disposable filters, clay packs, 3-micron pre-filters and finally 0.5-micron filters to ensure high product quality when entering the jet fuel storage tanks. The high cost of traditional filtration driven by a need for improved product quality drove the Nashville airport to consider alternative cost-effective methods for black powder contamination removal.
In 2018, the Nashville airport ran a test with a Black Powder Solutions’ (BPS) test magnetic separator on a jet-fuel slipstream. Based on the success of the test, the airport purchased and installed a full-size magnetic separator to process its ~4,400 barrel batches that are typically delivered over 3.5 hours from the pipeline system. The magnetic separator is the first line of defense for removing black powder as it is upstream of the various other conventional filtration systems. This unit has a magnetic array capable of holding up to 425 pounds of contamination before cleaning is required and is currently on a 4 month cleaning cycle.
The contamination removed from the magnetic separator during the 1st cleaning was sent out for lab analysis. That analysis indicated that (i) 20% of the contamination was at or under 1 micron in size with the median particle size at 37 microns (Table 1) and (ii) much of the black powder contamination consisted of iron-based compounds typical of pipe scale (Table 2). In excess of 10% of the black powder was under 0.5 microns, which would have passed the last stage of conventional filters and accumulated in the jet fuel tankage and further downstream. Subsequent 0.8 micron Millipore patch tests done both upstream and downstream of the magnetic separator identified a marked improvement in fuel quality and cleanliness (Figure 3).