If Dane County's latest push to combat climate change is successful, local watering holes might soon be serving suds carbonated with carbon dioxide made from decomposing trash.
"We'd be willing to use waste CO2 if it were properly tested and we were able to test it with our products," says the Great Dane's Robert LoBreglio, a co-founder of the local brewpub. "After that it's all logistics."
In his 2015 budget proposal, County Executive Joe Parisi has requested nearly $400,000 to test a patent-pending technology many believe is capable of capturing 100% of the greenhouse gas produced at the county's 220-acre solid waste facility on U.S. Highway 12 at County Road AB.
If the pilot succeeds, the county intends to sell the captured CO2 as compressed gas or dry ice. Says Parisi: "This is brand-new, cutting-edge technology."
Capturing CO2, however, is just one of three initiatives Parisi has proposed for the landfill, already in the renewable-energy vanguard. In 2011, it was honored by the federal Environmental Protection Agency for its compressed natural gas program.
"They are doing some innovative things at that landfill," says John Skinner, director of the Maryland-based Solid Waste Association of North America. "I don't know of any other landfill that is trying to capture CO2."
The budget, which the county board will deliberate on in November, also calls for a study on the feasibility of capping retired trash piles with solar power-producing membranes instead of the standard high-density polyethylene caps.
Parisi is also seeking approval to build a $3.6 million facility for recycling construction and demolition waste, which, on average, accounts for 30% of the landfill's annual trash intake.
Currently, eight semis haul this waste a combined 848 miles to the Fox Valley each day.
"That's a big carbon footprint," says the county's solid waste manager John Welch. "If we stop hauling that waste, and if we can grab that CO2 and put it into a marketable product, it could take us to a near zero-emissions facility. That would be very exciting."
The gases below
A large flock of gulls scavenge through exposed residential waste as Welch drives up one of the landfill's trash piles, referred to as cells. "On a nice clear day you can see pretty far from up here," he says.
As he rolls to a stop, Wisconsin's Capitol comes into view beyond the cell's curvature -- a primo view for the nature conservancy the landfill will one day become.
Since 1985, garbage collected in Dane County -- roughly 200,000 tons a year -- has been dumped here; then it is spread out in one- to two-foot-high layers that are compacted and covered with soil that supports the next layer of trash.
Once a pile rises 120 feet, it is retired and capped. A special leachate kept at what Welch calls "the optimum microbial level" percolates through the pile, breaking the detritus down and releasing a variety of gases, primarily the greenhouse gases of methane and CO2.
For two decades, the county has harnessed the methane both for revenue and savings. The cells are tapped into, and the gases, unseparated, are piped into six train engines converted to produce electric power not only for facilities onsite, but also 4,000 Madison homes.
"We were the first in the state to use that gas as fuel in these large engines," Welch says. "It barely passed the original vote. Now we're making over $3 million a year for taxpayers."
Taxpayer savings don't end there, however. Waste heat from the engines, which run 24/7, is piped to the nearby transfer station. Waste heat will also warm the proposed recycling center expansion, if approved by the board, as well as the new Highway Department Garage and Medical Examiner's Office being built across County Road AB.
And since 2010, the county has converted 40 vehicles to run on bio-compressed natural gas made by purifying methane, saving an additional $40,000 annually. Parisi says the fuel will eventually power the county's entire fleet.
"Wait until we get the snowplows running on that stuff," he says. "We'll see real savings there."
The CO2 challenge
In 2015, Parisi, who credits Welch with bringing many of these ideas to the table, plans to take Dane County's landfill where no landfill has gone before: near-zero emissions.
Until now, Welch explains, the energy required to separate CO2 from methane rendered past attempts financially imprudent. The new technology, he says, exploits "free energy" from exhaust heat rising from the train engines through a smokestack to capture the CO2.
"It is difficult because it's coming out of the smokestack at over 900 degrees [Fahrenheit]," he explains. "You have to grab it, cool it, and get it into a form where you can store enough of it to make it economical."
The landfill's annual CO2 output is equivalent to taking 12,000 passenger vehicles off the road, he says.
While Parisi is confident the technology will work, he says the bigger challenge is selling the CO2.
An analysis of the U.S. CO2 industry published in September by an Australian firm predicts that demand for CO2 will decline over the next five years, though growth is expected in some markets.
The overall decline is due to a drop in soft drink consumption, which generated 25% of the industry's $591 million in revenue last year, according to the report.
Ironically, for the county, the report anticipates the decline will be offset by high crude oil prices, which have spurred a boom in domestic drilling, "significantly boosting demand for CO2."
CO2 is used to extract oil and in pressurized tools, among numerous other industrial applications.
The report also states rising energy costs will mean higher operational costs for traditional CO2 makers, which it predicts will prod industries to search for cheaper sources of CO2.
Although fewer soft drinks are being sold, the report notes that beer, wine and juice consumption are growing. CO2 is used to carbonate beer and prevent fungal and bacterial growth in wine and juice. The quality of the landfill's CO2 will determine what markets are a good fit. Local brewers tell Isthmus they are open to using the landfill's CO2.
Noting his participation in a Madison composting program, One Barrel Brewing owner Peter Gentry says, "If we could extend that and make our carbon footprint even less by harnessing CO2 from a waste source, we'd consider paying a premium or dealing with any inconveniences."
Trash stars
The green projects Welch is spearheading have proffered a cool factor unusual for landfills, with roughly 100 tours given last year. Parisi jokes he may propose a full-time solid waste tour guide.
Of those who have toured the site, Parisi found a recent visit by German media validating, because Germany has long been a pioneer in environmental science.
Welch, too, is proud. "The county has had to take some risks, but that investment has paid off in a big way for taxpayers," he says. "Now elected officials are coming out here for photo-ops... because we're so cutting edge."
At national industry conventions, he says Dane County's landfill is the envy of trash bosses who can only dream of pursuing similar innovations.
"A lot of my colleagues say they wish they had elected officials that gave them that kind of leeway," he says. "Joe [Parisi] and the county executive before him and our county board give us enough rope to hang ourselves."
