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Landfill gases turned to compressed natural gas

In Grand Junction, Colorado, buses, garbage trucks and street sweepers run on compressed natural gas produced from a wastewater treatment plant.

In Riverview, Michigan, excess gases from a landfill are being converted to CNG to power seven city vehicles.

Plans are in the works to convert police cruisers to CNG, which costs about $1 per gallon.

And in Louisiana, St. Landry Parish installed a system in 2012 that can produce 240 gallons of CNG a day but recently expanded its production capabilities to produce 630 gallons a day. CNG not only fuels its own vehicles, but it is also sold to a large local waste-hauling firm to power its garbage trucks.

What started for Madison-based BioCNG as a small pilot project at the Dane County Landfill is spreading to other parts of the country.

And if gasoline and diesel fuel prices remain unpredictable, company officials believe their systems can help cities, counties and other government agencies, as well as private businesses, reduce fuel costs, lock in fuel budgets for up to two decades and let them market themselves as being friendly to the environment.

Mark Torresani, vice president of BioCNG’s parent company, Cornerstone Environmental Group, and the inventor of the company’s biogas conversion systems, said using biogas to power boilers in large manufacturing settings is common. However, only two or three companies in the country make systems to convert biogas to vehicle fuel.

But BioCNG is even more specialized.

“When we talk about the firms that are taking the biogas and using it directly to fuel cars and not putting it in a pipeline, we are the only one who is doing that successfully,” Torresani said. “Part of what we’re doing hinges on what does natural gas do as a vehicle fuel. Without the vehicles, there’s no market.”

The BioCNG system pumps biogas from a landfill or anaerobic digester. Hydrogen sulfide, moisture, volatile organic compounds and chemicals and carbon dioxide are then removed to create CNG. The product is then piped a short distance away to storage tanks and a fueling system that looks similar to a gas station.

BioCNG has nine systems in seven locations around the country, including two in Wisconsin. The company is also in the midst of building a $1.6 million facility scheduled to go online by the end of the year for the Las Gallinas Valley Sanitary District near San Rafael, California.

The Dane County Landfill system was built in 2010 to operate at a capacity of 100 gallons per day but was expanded in 2011 to produce up to 250 gallons of CNG a day. The system will be moved to the east side of the landfill in 2016 and get a $200,000 upgrade to increase storage at the county’s new highway garage at highways 12-18 and AB.

“We’re very happy with the system,” said John Welch, Dane County solid waste and recycling manager. “It makes economic sense for us because we save quite a bit of money on the fuel, but it also makes environmental sense.”

The county has about 500 vehicles but only 40 are equipped to run on CNG. Most are fueled at a county-owned station on Robertson Road with about 10 vehicles using the CNG produced from biogas at the landfill. But more vehicles will begin using CNG from biogas starting in 2016 when the landfill system is moved to the new highway garage. Snow plows could be a big user, Welch said.

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In 10 years, Dane County has a goal to convert most of its fleet to CNG, which would likely mean more expansion of the BioCNG system. Landfill gas is also used to generate enough electricity to power about 4,000 homes a day. That electricity is sold to Madison Gas & Electric.

“We’re working with a consultant to determine the future uses of our landfill gas and BioCNG is quickly rising to the top of that list,” Welch said.

In Janesville, the city has a BioCNG system at its wastewater treatment plant. The system was installed during a $34 million upgrade to the plant in 2012 and is used to fuel a Ford Taurus, three pickup trucks and a riding lawnmower.

Three more vehicles will be added to the city’s CNG fleet in the coming months with more than 40 being converted to CNG in the next 10 years, said David Botts, city utility director.

“We’re probably saving 200 to 300 gallons of fuel each month by not having to buy regular unleaded fuel,” Botts said. “There’s a lot of potential. It’s a technology that’s continuing to evolve.”

The Wisconsin State Energy Office reports 123 vehicles in Wisconsin used about 300,000 gallons of CNG in 2010. By 2013, 4,915 vehicles used 3.6 million gallons of CNG. By the end of 2014, 5,770 vehicles used 8.3 million gallons of CNG.

In recent years, Kwik Trip, Trillium, We Energies and other Wisconsin companies have opened CNG fueling stations that are open to the public while private companies and government agencies have built CNG stations to fuel their own fleets. In most cases, CNG comes from a pipeline or an on-site storage facility. The systems built by BioCNG, allow CNG to be manufactured and stored on-site and directly fuel vehicles.

The challenge, Torresani said, is convincing potential users to invest upfront with a payoff six or seven years down the road. It can cost around $8,000 to convert a gas or diesel vehicle to CNG. Systems to produce CNG from biogases at landfills, wastewater treatment plants and digesters can run between $750,000 and $5 million depending on the size.

Landfills and wastewater treatment plants are required by law to capture gases that are produced. Some convert some of the gases to electricity that can be easily sold to a utility with the remainder of the gases burned off. Some states and the federal government offer tax credits or grants for projects but it can still be a difficult sell.

“There never seems to be that capital for private industries unless a developer comes in and puts that money in up front,” Torresani said. “Municipalities are more forward thinking, I think, for their taxpayers. I would say the municipalities are taking the lead in pushing these projects forward. What it really takes is someone to be the champion in that community.”

Torresani, 55, has spent more than 25 years on projects focused on biogas and waste materials, but from 2006 to 2009 he developed a patent-pending process to convert biogases to CNG on a relatively small scale.

He moved to Madison in 1995 to start a consulting firm but in 2006 joined Cornerstone, an environmental engineering consulting company that specializes in solid waste and industrial markets. Torresani ran Cornerstone’s regional office in Plymouth, just west of Sheboygan, before the Madison office on the Far West Side opened in 2008.

Cornerstone, based in Middletown, New York, was purchased in May by Tetra Tech, a California-based consulting and engineering company. The acquisition could help expand opportunities for BioCNG systems in foreign markets, company officials say.

Torresani, who logged 50,000 miles on a bike traveling the world in the early 1990s and who worked in Hong Kong for a year as a civil engineer, saw large biogas projects in China. He also witnessed in Indonesia small uses of biogas in cooking.

“If they can do it there, why can’t we do it here,” Torresani said. “Why are only large projects economical to do? Why can’t we do something smaller and better here in the U.S.?”

This article was written by Barry Adams from The Wisconsin State Journal and was legally licensed through the NewsCred publisher network.