'We would take the heat from our incineration process and generate electricity.'
WASTE NOT: The energy generated by Synagro Technologies will be used to
power the Woonsocket incinerator and
any extra will be sold back to the city at
the lowest available commercial rate.
When Synagro Technologies Inc. and Woonsocket entered into an agreement to generate power at the company’s sewage incinerator, it was an unprecedented deal in Rhode Island. It’s the first time a local municipality and private entity in the business of sludge incineration will venture into the field of energy generation.
“The agreement allows Synagro to construct a cogeneration plant, where we would take the heat from our incineration process and generate electricity,” said Synagro Plant Manager David Abbamonte, a veteran of sewage-sludge incineration. “The agreement will allow the city to receive a $6.5 million deal on tax revenue over the next 20 years, additional revenue above and beyond what we were already paying the city for our waste-incineration plant.”
Synagro, with seven regional offices nationwide, including one in Woonsocket, plans a $10 million heat-to-energy cogeneration facility, retrofitting the existing incinerator to burn and dispose of sewage sludge.
Synagro purchased the sludge-processing facility in 1988, shortly after the city decided to privatize its operation. On July 26, the city’s budget commission approved a deal with Synagro to generate power at its incinerator, which takes in wastewater from Woonsocket and North Smithfield, and Bellingham and Blackstone, Mass. The Woonsocket wastewater-treatment facility treats about 10 million gallons of sewage daily.
The energy will be used to power the incinerator and any extra will be sold back to the city at the lowest available commercial rate to be used to power equipment at the wastewater-treatment facility. Synagro will continue to burn Woonsocket’s sludge at no charge.
According to Pamela Racey, Synagro’s national vice president of business development, the incinerator was upgraded in 2007 with a new fluid-bed technology to improve burning. Extra space was provided at that time in planning for future cogeneration. There will be no exterior construction associated with the project, equipment will be added into that framework to extract the heat and convert it to power. A steam turbine will convert the heat to steam, then to electric generation.
“There are no new emissions. We are capturing the air stream of what goes up the stack now and we’re stripping the heat our of it then putting it right back up, but at a cooler temperature,” Racey said.
According to data presented by the U.S. Environmental Protection Agency, there are approximately 170 sewage-sludge incineration plants in operation in the United States. There are 14 sludge incinerators in New England. Cranston runs the only other incinerator in the state.