Green Series: Good to the Last BTU

Feedwater to boilers is frequently the beneficiary of thermal recovery systems, providing steady demand for water closer to 212°F than 55°F. Source: Invensys.

A “pipe with a sprinkler system inside” is a lighthearted characterization of a waste-steam recovery system developed for saturated steam retorts, but significant energy is locked into the 200°F water that condenses from the steam. Source: Allpax Products.

Tanks and other equipment have been removed from the biogas system installed six years ago at a North Lawrence, NY dairy, leaving only the building shell. Source: Ecovation Inc.



Three on a therm
Efficiency vs. quality
Cool runnings
The risk in energy recovery |
Big capital projects usually stretch out the timeline for financial return, which is why third-party financing and operation of energy systems are gaining favor. Those arrangements carry risk, however, and the risk is borne by both the partner and the food company.
A biogas system at Coolbrands Dairy in North Lawrence, NY was the toast of the state’s Department of Environmental Conservation when it came on line in fall 2006. Built, owned and operated by Ecovation Inc., the anaerobic digester produced 150 million Btus of methane a day, replacing a third of the energy inputs needed to run the yogurt plant’s steam boilers. The dairy paid Ecovation for the gas at a cost lower than the 250,000 gallons of No. 6 fuel the methane replaced, Ecovation received an acceptable return on its $3.3 million investment, and the business model was applied to similar projects after Ecolab Inc. acquired Ecovation in 2008.
The win-win fell apart in April 2011 when the plant closed, and 132 workers were laid off. Upstate Niagara Cooperative Inc. subsequently purchased the plant and spent several million dollars on renovations before restarting production in October 2011, but not before the biodigester was decommissioned. Tanks, sensors, feeders and controls were removed by Ecovation, leaving a building shell and no prospects for restarting the system.
“The system became upset very easily if there was any change in the feed stream, but it produced a decent amount of gas for our boilers,” according to Matt Davis, plant manager of the renamed North Country Dairy. Despite the technical success and financial viability over four and a half years, the project underscores the vulnerability of long-term energy partnerships to unanticipated events.
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