September 2011:

Chris Antle of Swedish Biogas

Story and photo by Rhonda Sanders of the Flint Township View

Picture a green swath of vibrant grass replacing the weed-choked industrial lot that once held Buick City.

Brownfield recovery is one of many potential benefits that can be derived from biogas by-products, said Chad Antle, chief of operations for the Swedish Biogas plant located at the Flint Wastewater Treatment Plant (WWTP)) near Beecher and Linden Roads.

Speaking to the West Flint Business Association last week, Antle explained the workings of the year-old plant that converts human waste into usable biomethane energy. He also described its potential to fuel vehicles, home furnaces, stoves and other heat sources.

Digestate, or biosolids, which is the residual of the gas production process is now being disposed of in the WWTP incinerator, he said. But the material is a valuable biofertilizer.

“We’d like to see that incinerator turned off and make sure those digestates become available for farmers or agricultural or landscaping uses,’’ Antle said. ” It’s got lots of nutrients in it.”

Spreading it over brownfield sites like Buick City and Chevy in the Hole, then planting grass there would make those former industrial sites green again, he said.

Asked why that hasn’t happened, Antle said the biogas plant is in its infancy in the United States. Logistically the infrastructure at the WWTP does not exist to facilitate digestate recycling, he said, adding that it is not a new concept and is being done elsewhere.

But as public demand and “green” consciousness grows for alternative energy sources, Antle said he hopes someday to see biomethane filling stations in every city, biogas powered cars on the road and other uses that are common in Sweden which started doing this 50 years ago.

Antle also asked the business group for help finding food waste that also can be used in the biogas plant which is the process of adding equipment to upgrade biogas to its natural gas equivalent.

Restaurants typically have grease traps that capture a wealth of waste products that can be reclaimed as energy in the biogas process, he said.

Asked how the plant finds and collects food waste, Antle said the primary focus has been on getting the plant up and running. In the future, more effort will be placed on locating those substrate resources.

“That is why I mention it at meetings like this,’’ Antle said. “Help me find some substrates.”

“If you know of any business out there and they want to get rid of waste and it’s in liquid or organic form, please have them call me, we would be very interested.”

Antle said there’s ample capacity in the plant’s two million gallon processing tanks for materials to feed the microorganisms that generate biogas. Holly and Linden have helpfully contributed sludge material to the plant.

“They have good seed,’’ Antle said, evoking laughter.