California Looks to Biofuels to Tackle Bunker Cost Risks, as Well as Pollution

Scripps Institution of Oceanography at UC in San Diego has been investigating the viability of biofuels in research vessels.

The University of California (UC) says the Scripps Institution of Oceanography at UC in San Diego has been investigating the viability of biofuels in research vessels as a way to mitigate potential future increases in the price of traditional bunkers, as well as reduce pollution.

"Part of the Scripps mission is to protect the environment, and one of the most significant changes that we could make in our ship operations involved moving toward the use of cleaner, renewable fuels," said Bruce Appelgate, Associate Director of Scripps Institution of Oceanography.

"As scientists, we know we need to develop sustainable means of powering our ships to address pollution concerns as well as to mitigate future increases in fossil fuel costs."

Although Scripps' researchers were initially aiming to test renewable biodiesel made from algae, due to quantity availability issues, the study utilised a hydrogenation-derived renewable diesel (HDRD), called NEXBTL Renewable Diesel, from Neste Oil Corporation.

UC says that the biodiesel was a "drop in" fuel in that it required no modification to the ship's engines to be used, unlike some other varieties.

Scripps' study used HDRD to power R/V Robert Gordon Sproul from September 2014 to December 2015, in which time the vessel burned 52,500 gallons of 100 percent renewable diesel over a total of 89 operational days at sea, covering 14,400 nautical miles.

During the vessel's operation, the project team measured pollutants, including carbon monoxide (CO), nitrogen oxides (NOx), and organic and black carbon aerosols, as well as engine performance.

The R/V Robert Gordon Sproul is said to have been operated during the study period with two separate fuel tanks, one for the biofuel and the other for diesel, enabling the researchers to switch between both sources in order to compare the two fuels.

UC says data collected during the study showed that the vessel's NOX emissions were about 13 percent lower when running on the the  biofuel, particularly at lower operating speeds of 700 and 1,000 RPM.

However, operation using the biodiesel is said to have created 35 percent more particle emissions, compared to conventional diesel - especially while operating at higher speeds of 1,600 RPM - and produced "slightly" higher amounts of black carbon or soot.

"We were able to show that our existing ship ran as well if not better on biofuel," said Lynn Russell, an atmospheric scientist at Scripps, who co-led the project.

"The hope is that the price of biofuel will come down as the manufacturing process gets better understood, and as people test it and start adopting it. Now that there's proof of concept, it should be easy to keep doing it."

As Ship & Bunker has previously reported, biofuels have come under fire in the past from critics, such as Ike Kiefer, a faculty member at the U.S. Air Force Air War College, who said that efforts by the U.S. military to adopt biofuels would be unlikely to yield useful results.