Tour boat goes organic with soybean oil fuel

The usual diesel exhaust smell on the San Francisco tour boat Oski is gone, replaced by a scent more reminiscent of frying chicken or potatoes. This upgrade in aromas is a by-product of the Blue & Gold Fleet switching from diesel oil to a more environmentally friendly soybean fuel on the 87-foot, 400-passenger ferryboat. “We came to the conclusion about 1-1/2 years ago that we needed to start looking for alternatives or new technologies that would improve the environmental impact of our operations on San Francisco Bay,” says John Hie, vice president-engineering for Blue & Gold. “Basically, when it comes to existing vessels, you have three choices ? modify the fuel, modify the exhaust, or redesign some portion of the engine to improve the combustion cycle,” he says. “We looked at all three of these approaches with respect to diesel engines, along with such alternatives as fuel cells, diesel-electric, and hybrid power.” The steel-hulled Oski was built for Blue & Gold in 1978 by Nichols Brothers Boat Builders of Freeland, Washington as the lead boat of a three-boat series. It is powered by twin Detroit 1271 naturally aspirated diesels, and uses a conventional gearbox/propeller propulsion system. “At 23, Oski is one of the older vessels in our 14-vessel fleet,” says Hie. “She also is one of the dirtiest for emissions.” Blue & Gold also approached the problem from the standpoint of near-term, mid-term, and long-term solutions. “We decided to focus on the near-term ? finding a solution that would require minimal modification to the vessel and minimal capital expense,” Hie says. “Basically, we wanted ?off-the-shelf? technology. We were looking for progress, not necessarily a final solution.” Hie says the company ruled out modifying the exhaust of Oski for a number of reasons, not the least of which was that they merely would be correcting the symptom, not the problem. “Modifying the exhaust means creating a waste stream no matter what you do,” he says. “Also, there most likely would be a power penalty for, say, running a catalytic converter.” The decision was to go with a biofuel; in this instance, “virgin soy” ? minimally processed soybean oil. “There are all kinds and flavours of biofuels out there,” Hie says. “This one is quite a bit cheaper than those we have seen in the past, which ran about $3 to $4 per gallon delivered.” The virgin soy, a first pressing not unlike virgin olive oil, is costing Blue & Gold about $1.60 per gallon, compared with diesel fuel at about $0.95 to $1.00 per gallon. “We have been able to use this product without modifying our engines in any way,” Hie says, noting that the more soybean oil is processed, the more expensive it gets. “Also, and while this is not confirmed, it is my understanding that farmers are receiving a subsidy to produce soy beans for this particular product, which would tend to help offset the cost.” Initially, the company ran the soybean biofuel as a blend, but it is now being used 100%. Blue & Gold started looking for funding help with its biofuel project about a year ago, but when nothing happened, it moved ahead on its own. Then in late October, the US Maritime Administration made available a grant of $25,000, working through the San Francisco Bay Water Transit Authority. “The grant supposedly was to cover a maximum of one-half our demonstrated costs,” Hie says, “Although we anticipate it will cost us about $57,000 because we made it a two-phase evaluation. Later, we intend to add continuous water injection, which will take our investment to about $90,000.”