Utility District Scientists Turn Waste Grease into Fuel
Scientists Prove Biodiesel Could be Made on Large Scale
By Doug Oakley / Daily News Staff Writer
East Bay Daily News
“For a small group of scientists at the East Bay Municipal Utility District, the dream of producing a million gallons of biodiesel annually from restaurant waste is closer to becoming a reality.
The utility's treatment plant near the Bay Bridge processes each month about a million gallons of coarse, dirty kitchen grease flushed down local restaurant sewer lines.
About four years ago, scientists started researching whether it could be turned into fuel.
In August, they finished a pilot program that produced 50 to 100 gallons a month, demonstrating they can do it on a large scale.
Unlike other biodiesel producers who take used fryer oil, or "yellow grease," from restaurants and turn it into fuel, the utility is working with "brown grease," which until now has only been turned into fuel in tiny amounts inside laboratories, said Donald Gray, a senior civil engineer who came up with the idea to turn the substance into biodiesel on a large scale.
Brown grease is the most difficult to turn into biodiesel because it is so dirty and full of plastic, food and water that need to be separated, said Ben Horenstein, manager of environmental services. And when burned, it tends to produce air-polluting sulfur.
"We were taking the grease and processing it through our treatment facilities; then there was this concept that we can do what other people are doing with yellow grease," Horenstein said. "We've run four diesel trucks on it with 100 percent biodiesel and different blends, and we've had a lot of success."
If test results reveal tailpipe emissions are clean at the end of the month, scientists at the utility plan to urge the board of directors to construct a plant that could produce the 300,000 gallons of fuel needed to power its diesel engines for a year, and a whole lot more, Gray said.
"We're not really sure what we would do with the excess (up to 700,000 gallons a year)," he said. "There's the potential of selling to the trucks that go right by us on the way to the Port of Oakland. Or we could work out (a plan to sell) to another public agency."
Although a plant could cost anywhere from $900,000 to $4 million to build and the process is expensive by itself, the utility is in a good position to go forward because restaurants pay it to take the grease off their hands, Horenstein said.
"The interesting thing is, we think we would break even given the current price of diesel, but if you project the price out over 15 years, that's where the savings come in," Horenstein said. "Our interest is, can we be sustainable, do the right thing and make it cost-effective?"
Horenstein said that unlike the city of Berkeley, which lost a couple of diesel engines when it started running 100 percent biodiesel in its trucks a couple of years ago, his engines have "done super; we've had no adverse effects."
Alicia Chakrabarti, assistant engineer at the utility, proved that the biofuel could actually be made on a large scale, after doing research on paper.
She said there are environmental drawbacks to producing biofuel from crops such as soy beans because oil, gas and land are used to grow the crops in the first place. "So if we can produce fuel from a waste, it's very exciting," Chakrabarti said. "There are other ways to derive energy from waste such as producing methane for electricity, but to have something that can replace transportation fuel, that's even more exciting."
Gray said it's satisfying to scientifically prove that it's possible to make biofuel from sewage grease.
"There are other groups producing it from brown grease, but in very small batches, and I'm not even sure they have looked at whether it meets (engine and air quality) standards," he said. "It's harder with brown grease. For example, if you screw up the process you get soap instead of fuel."
