State representatives tour new, innovative FOG-to-biodiesel plant in Danbury, Connecticut

State Reps. Chaleski, left, and Callahan, center, recently toured the new biodiesel production facility at the John Oliver Memorial Sewer Plant in Danbury, Connecticut. (Photo: The Office of Connecticut State Rep. Patrick Callahan)

The John Oliver Memorial Sewer Plant in Danbury, Connecticut, is turning fats, oil and grease (FOG) from sewer-collection systems and grease separators at restaurant establishments into biodiesel fuel.

State Reps. Patrick Callahan and Rachel Chaleski recently toured the conversion plant, which went into operation earlier this year.

The FOG is pumped into the plant, captured and converted in an automated and continuous-flow system.

The city of Danbury is using the product, biodiesel B100, to power some trucks in the Public Works Department’s fleet.

It took little more than two years to construct and outfit the plant.

Prior to the plant being constructed, the FOG was concentrated, mixed with wood chips and either burned in an incinerator or placed in a landfill.

“As the ranking member of the legislature’s Environment Committee, I was interested to see how Danbury is not only leading the state but the nation in taking on the waste-management problem of FOG disposal,” Callahan said.

The biodiesel project was created through a partnership with UConn, Veolia North America, and REA Recovery Resources.

UConn Department of Chemical and Biomolecular Engineering professor emeritus Richard Parnas and REA’s patented reactor mixes refined brown grease with methanol to produce the biodiesel.

“I was pleased to learn that Danbury’s innovative efforts will save the city money on fleet operations,” Chaleski said. “This is a win-win for taxpayers and for the environment. Danbury partnering with a UConn research professor and moving field research into a commercial operation is an example of how municipalities or the state could work together on this inventive solution to handling waste.”

A mandate by the state Department of Energy and Environmental Protection led to a tremendous increase in the amount of FOG being collected at the waste-treatment plant, according to city officials.

City officials noted that the volume of grease coming into the treatment plant could be enough biodiesel fuel to run Danbury’s fleet of trucks for a year and still have a surplus to sell on the open market as a new revenue source for the city of Danbury of over $1 million.

As of July 1, 2022, Connecticut state law requires all home-heating oil contain a 5 percent biodiesel mix, which will go up to a 50/50 mix by 2035.

Many home-heating fuel companies in Connecticut were already blending their oil with biodiesel before the law went into effect but now there is a statewide standard for all companies moving forward.

According to a social-media post by Danbury Mayor Dean Esposito, the city’s grease-to-biodiesel project was established in 2019 and will generate nearly 282,000 gallons of renewable fuel per year, of which 222,000 will be B100 biodiesel fuel and 60,000 gallons will be boiler fuel.

Esposito said the project will gain an estimated net income of $1.3 million per year for the city.