Americas News
Algae-Based Biofuel Reduces Emissions by Up To 25%
The U.S. Maritime Administration (MARAD) has published its Final Report from a U.S. Navy study showing algae-based biofuels beat Ultra Low Sulfur Diesel (ULSD) for lower emissions and better fuel consumption on a commercial sized vessel.
The results, produced from the steady state ISO 8178 test which gives a weighted emission factor from five test points, showed nitrous oxides (NOx), carbon monoxide (CO), and carbon dioxide (CO2) were reduced by 10, 18 and 5 percent respectively compared to ULSD.
Particulate Matter less than 2.5 micrometers in diameter (PM2.5), which according to the U.S. Environmental Protection Agency (EPA) is believed to pose the greatest health risks, was reduced by 25% in the biofuel compared to the neat ULSD.
The biofuel was a 50/50 blend of neat hydrotreated renewable diesel (HRD) derived from the hydroprocessing of algal oils and ULSD, and was compared with neat ULSD.
The joint venture between the U.S. Defense Department and U.S. Department of Transport forms part of an ongoing programme to reduce America's dependency on petroleum.
Running the ship's engine continuously for more than 400 hours using the biofuel, the results from both fuels were then assessed based on the vessel's emissions and the effects on the engine.
Engine inspections for the Stalwart Class Modified Tactical General Ocean Surveillance Ship (T-AGOS 1), T/S State of Michigan, showed the effects of both fuels on either engine were exactly the same.
The report concluded that the addition of HRD to the ULSD showed "an improvement in heating value which resulted in slightly better fuel consumption performance".
A previous MARAD report and precursor to the recent study, estimated that U.S. commercial consumption of marine diesel in 2010 was about 2.25 billion gallons per year or approximately 7.41 million tonnes.
Based on those numbers and an average distillate carbon content of 82%, Ship & Bunker calculates that the algae-based biofuel blend would net up to 22 million tonnes less C02 per year compared to ULSD.
