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Salem Dairy to Produce Electricity from Manure by John Schmitz Capital Press - January 25, 2002

SALEM -- After several aborted start-ups, the biogas digester on Bernie Faber's dairy farm may finally begin producing electricity at full capacity next month.

"We've had so many (launch) dates that I kind of hate to talk about it anymore," said Faber, owner of Cal-Gon Farms.

While an improvement in the Northwest power supply picture has taken some of the allure out of producing electricity from cow manure, Oregon dairy and energy officials still believe the technology has merit.

Last year, Portland General Electric teamed up with Faber to build an anaerobic manure digester that produces enough methane gas to power a 100-kilowatt generator.

Because of added modifications, the original debut of the biogas system last fall was postponed until mid-February, when the digester will start producing continual power that will be fed into the PGE grid.

When the day does come when the unit is up to speed and PGE can confidently unveil it to the public, Faber expects a number of state officials, including the governor, to show up on his farm.

One of the principal reasons the digester is several months behind schedule is that PGE had to install a heated pumping system to agitate the manure once inside the digester. Not in the original plans, the pumps prevent manure from crusting up at the top, Faber said.

Jim Krahn, executive director of the Oregon Dairy Farmers Association, said that even though financial incentives for producing additional electricity today have slackened, manure digesters have other far-reaching benefits, especially environmental, for dairy farmers.

For one, digesters allow dairymen to contain and collect phosphorous, and element that regulators are keeping a close eye on these days.

Digesters also remove a lot of the odor from dairy farming and can kill and/or contain the spread of any pathogens, which are killed during methane production.

Yet another advantage is that nitrogen left over after methane generation is in a form more readily available to plants.

Faber said that if anything, the digester will make his job easier. His only responsibility is to keep an eye on it. If it malfunctions, he's on the phone to PGE. "That was the deal."

Krahn said that now that the power shortage in California has pretty much disappeared and electricity futures prices have fallen, several biogas projects in that state have been put on hold. "There just isn't enough money in electricity to make them pay at this point."

PGE is also involved with building a much larger manure digester in the Boardman, Ore., area, where, eventually, waste from 20,000 dairy cows on Three Mile Canyon Farms will be used to generate 40 times the power produced by Cal-Gon Farms.

That system is due to be fully operational in the third quarter of 2003, said Jeff Cole, PGE's biogas program manager.

Waste from Bernie Faber's 450-dairy cow operation is scraped from a concrete pad and pumped into the digester.

There, natural fermentation takes place that produces methane gas. The gas is used to fire the 100-kilowatt generator.

Before the gas is burned it first must pass through a scrubber that removes any sulfur, which is corrosive.

The round digester, which has a 100,000-gallon capacity, is fed manure on a continual basis day and night. It takes about 12 days for all the methane to be produced.

The digester is made of 1-foot thick reinforced concrete, is 25 feet tall and has a diameter of 28 feet at its widest point.

Once the methane has been collected, the remaining slurry, which contains some solids, is sent through the separator and then to the lagoon.

Solids from the separator will be used for bedding after any phosphorous has been removed.

Jeff Cole, biogas program manager for Portland General Electric, said that the Cal-Gon Farms digester will rely solely on mesophilic bacteria naturally present in the cow to produce the methane gas.

Mesophilic bacteria live and reproduce and moderate temperatures.

The Faber digester has been designed so that waste streams can be diverted away from the digester and into the lagoon if desired.

Related Pages:
California Dairy Group Hopes Manure Program Breaks the Bank by Staff, Environmental News Network, 8/15/1