As I mentioned in my last blog, the conversions, integrations and colocations issue of Biomass Magazine is coming up in December, so I’ve been on the lookout for good stories. (Power plants moving from coal to wood pellets. Fiber board plants converting to wood pellet manufacturing facilities. Paper plants building combined-heat-and-power plants on site to become energy independent and sell to a neighbor or the grid).

Some stories are more obvious and attract more attention than others, and this week I came across one that was under our radar. However, it’s really unique and definitely worth sharing the news about.

There’s a company called Trenton Biogas in New Jersey that is in the process of converting a shuttered sludge dewatering plant to a food waste/organics-to-energy facility.

Cool enough, making use of existing assets just gathering dust. But the really interesting thing is that the plant was built in the late 1980s/early ‘90s, but has actually never been used. Yesterday I called up Peter Joseph, a project principal, and he told me why that is, and the story of how this whole project came about.

It goes like this:

In the late 1980s, the federal government and four townships (Trenton, Hamilton, Ewing and Lawrence) partnered up to use Clean Air Act money to build this dewatering facility, which cost more than $80 million to build. “The original intent was to use a technology to dewater sludge coming from the adjacent sewer authority, dry it, pelletize it, and sell it off as fertilizer,” Joseph explained.

When the plant was complete and being commissioned, the EPA made a move that drastically changed project economics—it recharacterized sewer sludge material as a nonhazardous waste, which had previously imposed a significant cost to the sewer authority and was a main project impetus. “It completely undercut the business model for what they were trying to do with this facility,” Joseph said.

So there it was. An expensive, brand new plant that now made no sense to use, and the municipalities left to pay for it all this time.

Interestingly, three other similar facilities were built in the U.S.—another in New Jersey and two in California—but, as Joseph told me, they were dismantled and the parts sold off.

This one, however, has been maintained by the Mercer County Improvement Authority, which has been hoping someone would come along and be interested in the infrastructure and location, and finally, that person did.

Joseph said that when he evaluated the site, he realized the infrastructure would be great for an anaerobic digestion facility. So for the past few years, he and his team has been working with MCIA and now have an option to purchase the facility. It will take in contracted organics (a permitted capacity of 300 tons daily) and convert them, via AD, into power and renewable natural gas, and the solids left over will be sold off as various ag amendment products.

The 1.1 MW of power will be used on site and sold to the plant’s original main customer—the local sewer authority—to take the facility off of the grid,

An AD technology supplier has been selected, Joseph said, but wished to keep it confidential for now.

“The facility is very well located to accommodate central and northern New Jersey markets, even New York City, and it’s very logistically attractive. We’re in an industrial area, so we don’t have the usual NIMBY or local issues,” Joseph said. “In fact, we’ve been very nicely embraced.”

 Trenton Biogas recently completed a project milestone—it scored an operating permit from the New Jersey Department of Environmental Protection in early September, which Joseph said was “a very rigorous process.”

If all goes well, construction of the retrofit will be underway within a month or two, he said.

And that’s that.

I look forward to following this project—best of luck to Trenton Biogas.