Granite Geek: Raw vegetable oil replaces heating oil at Keene State

  • On the left is a sample of the vegetable oil being burned, and on the right is the heating oil it replaces.  Keene State College

Monitor staff
Published: 10/11/2016 12:25:12 AM

Keene State College has started to burn a lot of vegetables, and that’s not a college-cafeteria joke.

The school has retooled one of the three boilers that heats the campus so it can burn waste vegetable oil – not traditional biodiesel or ethanol – made by a Massachusetts company using a secret process. The school estimates the fuel will generate about 36 percent of the energy for creating the steam that heats Keene State, replacing about 100,000 gallons of fuel oil.

KSC says it may even save money by switching from No. 6 or No. 2 heating oil to this vegetable oil because operating cost per BTU will be about the same, but using this waste fuel can earn some renewable energy credits.

The move also diversifies energy sources, helps the school cut its greenhouse gas emissions and reduces some of the air pollution that plagues Keene due to geography (it sits in a very big bowl where bad air can collect).

There are even some really, really local pollution benefits, especially compared with No. 6 heating oil.

“We had been receiving complains about No. 6 delivery, about the noxious fumes. The heat plant guys talk about how much nicer this is,” said Cary Gaunt, Keene State’s director of campus sustainability, in a recent interview. “There’s less off-gassing, less headaches.”

The waste vegetable oil comes from a Marblehead, Mass., company called Lifecycle Renewables, which makes it out of used cooking oil collected from restaurants, cruise ships, hospitals and the like. Its process is proprietary and the company declined to comment on the Keene State contract, probably because even though it’s been around a decade, it’s in a sort of “stealth mode” with this technology, trying to grow before big competitors like oil companies take notice.

Turning organic material into liquid fuel carries a double benefit, cutting waste as well as replacing fossil fuel, but it is harder to do than it sounds. I’ve been writing about local biodiesel and cellulosic ethanol companies for years, but the economics and/or technology has always squashed them.

Lifecycle Renewables’ process seem to be quite different. Gaunt said she believes it mostly involves filtration, which would be much cheaper and simpler than the catalyst-driven process known as transesterification that creates biodiesel fuel, or the distillation involved in turning corn into ethanol for gasoline.

However it is made, at Keene it is acting as a “drop-in fuel,” an industry term for a liquid fuel made from organic matter that can be used as a replacement for liquid fossil fuels, with little or no tweaking needed. The boiler being used had previously been changed to burn lighter No. 2 fuel oil, a move to diversify from No. 6 fuel oil, so the transition was easy.

“When it comes to us, it looks like a bottle of vegetable oil that you’d buy at the store,” said Bill Rymes, the school’s plumbing and heating supervisor.

Rymes said the school was cautious about this product because the wrong fuel can really mess up equipment, as anybody who has mismeasured the mixture for a two-stroke engine knows (who, me?).

“The boiler manufacturer wanted a fuel sample to be sent out to them, so their R&D tested it, came back fine,” said Rymes.

Among other advantages, it needs to be heated to only 130 degrees when injected into the boiler to liquefy it for atomization, compared with 210 degrees for No. 6 heating oil.

One drawback to this waste vegetable is its energy density. It contains about 130,000 BTU (a measure of heating energy) per gallon, compared with 152,000 BTU for No. 6 heating oil. So more volume is needed per unit energy, adding to shipping and storage costs.

Gaunt said pricing varies but the oil’s price tends to follow the No. 6 oil market. A key financial point is that the school hopes to make as much as $30,000 in renewable energy credits, paid as an incentive to switch from fossil fuel.

“This is an experiment for us, with renewable energy credits. We have a ceiling that we won’t go over,” she said. “The safe thing to say is that it should be comparable to No. 6, plus (income from) credits.”

(By the way, the CEO of Lifecycle Renewables is also named Gaunt, but the school says the two are not related.)

As for Rymes, he said he’s a convert. That’s not a trivial matter, because in my experience plant managers tend to be suspicious of change – understandably so, because they’re the ones who get yelled at and who have to fix things if novelty goes wrong.

“I don’t see any drawbacks. It has burned without incident. Once we got the final adjustments, it ran just fine,” he said. “We’re burning an alternative fuel that nobody else is burning and creating less (greenhouse) gases – that’s the most rewarding part.”

Gaunt put it a little more colorfully: “We’ve looked under the bed, haven’t seen any dust bunnies. I think it’s the real deal.”

(David Brooks can be reached at 369-3313, dbrooks@cmonitor.com or on Twitter @GraniteGeek.)


David Brooks bio photo

David Brooks is a reporter and the writer of the sci/tech column Granite Geek and blog granitegeek.org, as well as moderator of Science Cafe Concord events. After obtaining a bachelor’s degree in mathematics he became a newspaperman, working in Virginia and Tennessee before spending 28 years at the Nashua Telegraph . He joined the Monitor in 2015.



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