Algae Powers New Fuel

TC ship part of nation's defense, transportation study

TRAVERSE CITY – An algae-based renewable fuel may someday power Navy ships and commercial maritime vessels. If so, Traverse City and its Great Lakes waters will have played a critical role in its development.

This past fall, the 224-foot former Navy submarine surveillance ship – the T/S State of Michigan – headed out from its dock at the Great Lakes Maritime Academy on West Bay with algae-based fuel powering one of the ship's four engines. The vessel is the training ship for students in Northwestern Michigan College's maritime program.

The project is a joint effort by the U.S. Department of Defense and the Department of Transportation (Maritime Administration) to reduce the nation's dependence on petroleum both at home and in Afghanistan and Iraq. By 2016, the Navy wants to deploy what it calls a "Great Green Fleet" of nuclear vessels, hybrid electric ships and other ships and aircraft powered by biofuels.

The fuel – known as hydrotreated renewable diesel or HRD – is made from algae and blended 50 percent with an ultra low-sulfur diesel and a lubricant additive.

The State of Michigan is operated by the Great Lakes Maritime Academy but is owned by the federal government, explains Academy Superintendent Jerry Achenbach. He says the Maritime Administration contacted the Academy about seven months ago about testing the fuel in its ship.

"They were looking for a certain-sized vessel that fit the profile," Achenbach says. "It's an important consideration for the Navy and we're happy to help provide the data to make the best decision."

T/S State of Michigan was just one of many ships used for the alternative fuel study – the largest of its kind to date.

Harvested algae, like fossil fuel, releases carbon dioxide when burnt, but the carbon dioxide is also taken out of the atmosphere by the growing algae. Among the environmental benefits: algae can be grown on wastewater, or in a fermentation tank, absorbing carbon dioxide. Also, the crude oil yield is expected to be higher than from other biofuel sources, such as corn, and is produced from a non-food stock.

In total, the study aboard the T/S/ State of Michigan spanned 17 days and logged 170 hours of at-sea time, according to NMC's Maritime Academy. All trips were under 12 hours, as after that the ship requires a larger crew, says Achenbach. The at-sea testing was followed by at-dock testing – essentially turning the engine on and off – that just wrapped up last month.

Specific data being measured includes the fuel's emissions, efficiency and affect on engine performance and endurance.

"Our smaller vessels have operated on biodiesel fuels for years," adds Achenbach. "We've seen the environmental benefits ourselves."

The study's raw data is currently being compiled and studied with an expected release in Feb. 2012. BN