Minnesota's first renewable natural gas facility opens at Inver Grove Heights landfill

Minnesota's first renewable natural gas plant is up and running at an Inver Grove Heights landfill, turning biogases produced by trash into fuel for heavy-duty vehicles.

New York-based OPAL Fuels built and operates the facility, while Republic Services, an Arizona-based company that owns Pine Bend Sanitary Landfill, leases out the land and supplies the biogas. The end product — renewable natural gas — then goes into Xcel Energy's gas pipeline.

"The fact that we can remove or basically eliminate 44,000 metric tons of carbon through this project … every year is very impactful to the communities where we live and work," said Tyler Kraft, general manager at Republic Services, which is involved in 77 similar projects nationally.

The plant has been operational since August but still is ramping up to reach full capacity, Kraft said.

Pine Bend is the largest open landfill in Minnesota and encompasses 255 acres in the southeast metro. The new site, which cost about $40 million to build, is situated on 100 acres on the western side of the Pine Bend property.

Inver Grove Heights has enthusiastically approved the building of the new plant, said Heather Rand, the city's community development director. The city welcomes clean energy projects like this one, she said, "and the investment and jobs this growing sector provides."

The new site replaces an aging plant at Pine Bend that turned methane into electricity but closed several years ago because it became inefficient.

The process of producing natural gas at the 12,000-square-foot site begins with the collection of biogas, which is about 50% methane and is created by the trash in the landfill. Nitrogen and sulfur are eliminated from the mixture, and the methane is separated from the carbon dioxide. The final product — methane — goes into the pipeline and can be pulled out for use at fueling stations.

"What we wind up with is a near-pure methane product that's virtually, molecularly, identical to fossil methane," said Jonathan Maurer, co-CEO of OPAL Fuels.

The fuel is used by GFL Environmental and Waste Management garbage trucks, Maurer said, as well as UPS trucks. Renewable natural gas works in large trucks that cannot be powered by electricity because the necessary batteries would weigh too much, he said.

The Inver Grove Heights plant produces enough to permanently convert about 500 heavy-duty trucks — each traveling 300 to 500 miles a day — from diesel fuel to renewable natural gas.

Renewable natural gas is cheaper and cleaner than diesel, Maurer said, and eliminates the sulfur and nitrogen oxide emissions that would have been produced if the methane were burned off as a flare or used in engines.

Maurer said he believes "we're going to see more and more and more" use of renewable natural gas, although only about 1% of heavy-duty trucks use the fuel today.

About 500 million gallons of renewable natural gas is produced annually in the U.S., he said — a drop in the bucket compared to the 40 billion gallons of fuel used by heavy duty trucks each year.

Kraft, the general manager at Republic, said his company is interested in more such projects.

"We want to be sustainable and be good partners in the communities," he said.