Alcohol & Boat Engines, Is There Another Way?
By Ryck Lydecker
Federal law says the nation must increase its "biofuel" capacity dramatically in the next decade, but does it have to be ethanol?
It's zero-dark-hundred at an undisclosed marina somewhere on the western shore of the Chesapeake Bay. Two men noiselessly transfer gear from the covered bed of a pickup truck to the cockpit of the non-descript center-console outboard at dockside. Quickly they stow hoses, canisters, and meters, plus vinyl pouches that sprout tubing with stainless-steel fittings. Two others silently remove unmarked barrels from a storage shed, wheeling them toward the boat.
Finally the men whisk a secret weapon known only as "MPSS" aboard, a white metal cabinet the size of a large ice chest. Laid flat on the cockpit sole, it's below sight from curious eyes that may pass in another boat, or attempt to spy from shore.
A verteran Mako 19 powered by a conventional two-stroke outboard, one of three boats used for isobutanol fuel testing. Photo by Emily McKnight
Once loaded, two of the team begins rigging the MPSS to its attendant vinyl bag, the hoses tracing umbilicals to the exhaust system of the 175-hp Evinrude E-Tec engine on the transom. It takes more time to rig a battery of sensors — from water temperature and barometric pressure, to fuel flow and boat speed — but eventually and with little fanfare, the boat heads for a quiet creek that shall remain nameless. Once on the unmarked, one-mile-course track, the boat begins a repetitious navigation routine — up and back, up and back — as team members monitor the MPSS, now sucking samples of engine exhaust into the pouch.
This being mid-week, such boring, back-and-forth operation at various speeds apparently goes unnoticed from shore. Two minutes at 5,000 RPM, five more at 4,000 and so on, through a five-stage protocol from wide-open throttle to idle speed in neutral. After several laps, one crewmember switches out the portable fuel tank while another screws tubes from a fresh pouch into the MPSS. The routine repeats, lap after measured lap, until the technical appetites of both pouches are satiated and the boat heads back to the dock.
There, while two men unload equipment and reconfigure the boat to its inconspicuous, every-day appearance, the other two whisk the pouches into the truck. They head south where a late-night rendezvous with a gas-mass spectrometer awaits at an undisclosed lab three hours away. Anticipation in the truck is electric. The secrets the two pouches hold could do no less than revolutionize recreational boating.
Team BiobutanolAll melodrama, intrigue, and clandestine-op allusions aside, the description above is a slightly embellished version of how three marine-industry engineers put together their equipment and expertise in an effort to solve the problem an ethanol increase in gasoline poses for boat-engine manufacturers and boat owners. After a series of on-the-water evaluations and laboratory tests conducted over the summer with, not ethanol, but another alcohol derivative called isobutanol, it turns out they may be on to something.
Evinrude engineer Jeff Wasil loads a fresh emissions-trapping pouch into the Marine Portable Sampling System (MPSS) that he designed.
"We know that increasing ethanol content in gasoline to 15 percent wouldn't be good for modern marine engines, which today are designed to run on 10-percent ethanol," reported John McKnight, environmental and safety compliance director for the National Marine Manufacturers Association, who helped organize the on-the-water evaluations. "Ethanol adds oxygen, making engines run hotter, so if they increase the amount to 15 percent in the gasoline, that could lead to mechanical failures." McKnight is referring to the ethanol industry pressing to raise the content to 15 percent, and the partial approval for that given last year by the U.S. Environmental Protection Agency.
"The National Renewable Energy lab sanctioned a series of performance and durability tests on both two- and four-stoke outboards (see sidebar) and we know that E15 can seriously damage those engines," Mc Knight added. "Right now in the U.S. we use 14 billion gallons of corn-based ethanol in gasoline, but the nation is under a federal mandate to increase biofuel consumption to 36 billion gallons by 2022. So we thought it was time to look for an alternative to ethanol, and after analyzing our tests of last summer, we may have found just that in isobutanol."
Although discovery of isobutanol as a byproduct of plant fermentation goes back to 1861, it's only due to innovations in biology over the past 20 years that it's become a viable and potentially cost-effective fuel source, according to chemical engineer Dave Munz. As a member of the team that conducted the June boat trials, Munz and his company, Gevo, a Colorado-based isobutanol producer, supplied the fuel. Isobutanol, Munz said, is everything ethanol isn't; it's non-hygroscopic, meaning it absorbs little water, and its use would avoid the fuel phase-separation problems in boat engines that aren't run regularly. In addition, isobutanol is not as potent a solvent as ethanol, so it might be the panacea for older boats with fiberglass fuel tanks.
From a distribution-cost perspective, Munz explains that because isobutanol is less corrosive than ethanol, it can be shipped by pipeline as opposed to the more expensive truck and rail transportation that ethanol demands. "We think it can solve a lot of problems for the fuel industry, as well as for the consumer," he adds.
The EPA has ruled that isobutanol, even at a higher percentage, is a "substantially similar" fuel, meaning that small retailers like rural convenience stores and marinas should not have to retrofit or replace their gas pumps, which can help keep prices down. That "higher percentage" is one of isobutanol's chief advantages: It's got 30 percent more energy than ethanol.
Fuel Of The Future?Gevo, in fact, supplied isobutanol fuel for an entire summer of testing, according to John Adey, technical director for the American Boat and Yacht Council and a member of our BoatUS Magazine tech team writing "Ask The Experts." Adey handled logistics for the four-month project and designed test protocols that put three boats through their paces on isobutanol.
"By the time we were done in September, we'd gone through about 800 gallons of isobutanol-enhanced fuel," Adey reported. "We wanted to conduct the scientific emissions tests, but also just to operate the boats on this fuel the same way regular boaters would during a summer." Adey's work actually started in March, prepping the boats: a Mako 19 with a 175-hp Evinrude E-Tec, two-stroke outboard; an 18-foot Sea Ray with 135-hp Mercruiser inboard/outboard power; and a 23-foot Sea Doo with twin 215-hp Rotax engines driving its jet pump. In addition to the calibrated and controlled emissions testing in June, Adey, McKnight, and others (including a few BoatUS staff who were asked to help) logged 40 hours, what EPA determines the average "seasonal life" for recreational boat engines, on each boat.
Volvo Penta engineer Rich Kolb (standing) operated the Mako during June exercises to capture engine emissions for later testing at the firm's laboratory in Virginia.
The June emissions testing with the Mako provided a baseline for the entire summer suite of evaluations. According to Jeff Wasil, engineering technical expert for Evinrude Marine Engines, and inventor of the MPSS, which stands for Marine Portable Sampling System, the first "bag run" captured exhaust with the engine burning a pure, EPA-approved, test gasoline called Indolene.
"Two years ago we investigated how isobutanol would work in one of our outboards and its properties seemed much better suited for marine engines," Wasil said. "We found no appreciable changes in emissions and because you get more energy without more pollution, and with a fuel that appears to be more compatible with marine engines, isobutanol looks more promising than ever as a replacement for ethanol."
Coming To A Pump Near You?Wasil notes that the U.S. Department of Energy has designated isobutanol a "drop-in fuel," meaning that it can be used to displace petroleum under the Energy Independence and Security Act of 2007, and increasing its use could help reduce greenhouse-gas emissions faster as well. It can be produced from agricultural waste products like corn stalks, or from switch grass and wood chips. At last count at least 10 companies worldwide, including a BP-Dupont joint venture called Butamax were working toward commercializing isobutanol in the next few years, according to chemical-industry reports.
"There is no need to rush E15 into the marketplace," Wasil told the House Subcommittee on Energy and Environment in testimony for NMMA last July 7. He appeared before the panel to address the risks of the EPA's "partial wavier" allowing 15-percent ethanol fuel, or E15, to be used in some engines and not others. He told lawmakers, "Let's have a strategic pause while more testing is done to determine the effects of E15 on various kinds of engines and to see whether there might be alternatives to ethanol, such as isobutanol."
With the baseline emissions tests quite literally in the bag and a full summer of routine operation logged on all three boats, at press time Team Isobutanol planned to conduct the emissions test sequence again and look for anomalies. "We want to find out if, after 40 hours of running time, the engines still comply, or if there were any ill-effects," Adey explained in late summer. "So far, the engines are running better than ever. Power is excellent and fuel economy seems improved; in fact, I'm amazed at how great this fuel seems to be."
But if one of the engines doesn't pass the next "bag test," scheduled for the fall, after boating season, Adey said technicians would tear it down and determine how any failures may relate to the fuel. As Wasil put it, "It's important for the marine industry to secure a fuel that we know is going to work in our products and that consumers can depend upon." McKnight said a full report on the project would be ready for presentation at the Miami International Boat Show
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How Bad Can More Ethanol Be?Gasoline-engine manufacturers and the millions of Americans who use their products have lived with 10-percent ethanol in their automobiles, trucks, boats, generators, and lawn mowers for at least the last decade. Manufacturers and the marketplace have adjusted to the requirement, the public is using it, and air quality is better for it.
Two years ago, ethanol manufacturers began to push for half-again as much ethanol in our gas tanks, which is 15 percent, or what would be called E15. So what could be wrong with 50 percent more ethanol in the gasoline that powers our boats? Plenty, according to a new study conducted by Brunswick Marine and Volvo Penta, which was financed by a $400,000 grant from the U.S. Department of Energy and monitored by the National Renewable Energy Laboratory. For example, a total of 300 hours of E15 running time on three popular models of both 4-stroke and 2-stroke outboard engines (check the website below for specific engines), as compared with running on pure gasoline, showed metal fatigue, misfiring, emissions, and deterioration of some fuel-system components.
The peer-reviewed tests also ran a carbureted 4.3-liter, 4-stroke inboard engine on E15 and it exhibited cold-start problems and increased emissions. For test details, go to www.nrel.gov/docs/fy12osti/52909.pdf.