Deerfield’s Bar-Way Farm Methane Digester to Put Manure, Food Waste to Work
The Recorder, May 18th, 2016, by Richie Davis
After trying for more than seven years, Bar-Way Farm is installing a system to turn the 25 tons of manure its 500 Holstein cows produce daily into electricity, heat and fertilizer.
The $4 million methane digester being built at the fourth-generation Mill Village Road farm will not only make the operation more economically viable, says Peter Melnick, a partner in the farm, but will also help the state’s nearly year-old commercial food waste ban by providing a receptacle for organic material from supermarkets, restaurants and manufacturers.
Expected to begin operation by Thanksgiving, the digester designed by Ottawa-based CHFourBiogas will make use of the 25 tons of manure, combined with 45 tons of food waste a day in a hydrolyzer that begins the process of anaerobic digestion at 105 degrees in a 100,000-gallon tank. The material is pumped every 20 minutes from there into a 700,000-gallon, oval-shaped concrete receiving tank built 12 feet into the ground and rising an additional 12 feet above ground, with an insulated rubber dome roof to collect methane resulting from the anaerobic digestion.
“It’s exciting,” said Melnick as he watched the Kocot Construction crew preparing the site of the racetrack-like tank, roughly 100 feet by 50 feet, where two boat propellers on opposite ends of the track will push the waste down the center straightaway, then around the bend after it’s slowed to the opposite section.
“It really is a way to make a dairy farm in the Northeast sustainable, especially in Massachusetts, where we have good access to food waste, and we have a lot more acres than cow manure.”
The tank’s oval design, he said, makes the digester more efficient than what was available even just a couple of years ago.
“If you mix it in a round tank, the sediments go to the middle, where they settle and build up over time,” said Melnick. “This won’t settle.”
The farmer has formed a separate company, Bar-Way Gas LLC. It worked with Vanguard Renewable of Wellesley, a $400,000 grant from the Massachusetts Clean Energy Center and a $335,000 grant from the U.S. Department of Agriculture’s Natural Resource Conservation Service to build what will be the first high-efficiency methane digester using the improved CHFour technology. Other digesters have been built at Hadley’s Barstow Longview Farm, and before that at the Jordan Farm in Rutland.
Both of those digesters, built together with AGreen Energy, have been incorporated to the Vanguard Renewables family of digesters, with the idea of having the three, along with three more now planned over the next 18 months for other parts of the state, able to be operated remotely from a single location, said Managing Director William Jorgenson.
Vanguard, which will operate the digester as well as work with Casella Resource Solutions to acquire large quantities of food waste from Tulum Trust, which provides private equity specifically for projects that help reduce the threat of climate change, said Jorgenson.
The design improvements include the racetrack-shaped tank, which allows more surface area for the enzymes to work, with more holding time, Jorgenson said. There’s also a chopping mechanism that allows the processor to take solid as well as liquid food waste, making the particle size smaller, “so you get two bites of the apple to make those enzymes more efficient and capable of producing more gas,” he said.
Because the new design allows for processing of solid food waste, Jorgenson said, it will help the state’s ban on dumping organic waste in landfills and incinerators, which applies to all commercial producers of more than 1 million tons of food waste a week. A potato processing plant, a meatball plant, as well as outdated supermarket produce and prepared food waste will be able to be treated, he said, “in a way that doesn’t upset the ecosystem of the farm. We don’t want to be turning the farm into a garbage dump, and it allows us to do this in a way that’s respectful, not making stuff smell.”
In fact, Melnick added, the digester — with a Recycling, Composting or Conversion permit from the state Department of Environmental Protection that limits the volume and type of material coming in, as well as the noise and the hours and numbers of trucks that will be allowed for the operation — will enable the farm to get rid of its manure in a way more favorable to neighbors.
“We can utilize the electricity and the heat, and the odor reduction will make us better neighbors,” he said. “This is going to make us so much more sustainable for the next century, so we won’t have to rely on just the milk check.”
That check is now generating about $14 per dozen-gallon hundredweight of milk, which is about half what it was a couple of years ago, Melnick estimates, and $4 less than it costs to produce the milk.
Melnick said he expects the farm will save $20,000 in heating fuel a year, so there are plans to build a greenhouse to grow crops year-round.
A byproduct of the process will be a bedding material that can be used instead of sawdust.
In addition, with about 700 acres of cropland, the new digester will produce an organic fertilizer so the farm won’t be spending money on commercial fertilizer.
“That’s a huge savings,” Melnick said, and since manure odors will be reduced by 90 percent, it will be easier on the neighbors. “Nothing’s going to arrive on a garbage truck.”
Bar-Way will use less than 10 percent of the electricity produced by the equipment, and the rest will be sold to the grid. The processor will also produce 3 million BTUs of heat an hour, 25 percent of which will keep the digester running, with the rest used to heat the farm’s buildings.
“This is what’s kept me going on the digester (project) all these years,” Melnick said. “It just makes so much sense.”