Becoming a Biorefinery

What we are doing is changing this ethanol plant into what we call a biorefinery.”

That was GreenField Ethanol chairman and founder Ken Field commenting on the recent announcement of a first-of-its-kind greenhouse in North America that will make use of surplus heat and carbon dioxide supplied by GreenField’s Chatham facility.

According to GreenField Ethanol’s vice president of business development Barry Wortzman, it’s a kind of synergy the industry is moving towards, especially considering each tonne of corn used in the ethanol process produces a third of that weight as carbon dioxide.

“A biorefinery is where nothing gets wasted. You’re not venting anything into the atmosphere – you’re using your CO2 for another application.”

The $65-million project on Bloomfield Road, across from the plant, will see 22.5 acres of greenhouse owned by Cedarline Greenhouses producing up to 21 million kilograms of tomatoes annually. The first crop will be planted next July. The second phase will see up to 90 acres of greenhouse over the next 10 years.

The partnership will help to significantly reduce the greenhouse’s energy footprint by lowering heating costs by 40% while increasing tomato production by 5%, according to Greg Devries, owner of Cedarline.

Devries said tapping into GreenField’s waste heat and carbon dioxide should also allow the greenhouses to be operable year-round, rather than being idled during the winter because of high heating costs.

GreenField will update the technology at the plant, which currently doesn’t include waste heat recovery or a thermal oxidizer. The new technology will condense stack heat through a series of exchanger systems, allowing the ethanol plant to supply hot water to the greenhouse. The water will then be returned to the ethanol plant through an expanded cooling water loop.

The company is also installing technology that will allow it to develop a new co-product from the ethanol process – namely, corn oil.

“We’ve incorporated a known technology at our Chatham plant that will allow us to remove the corn oil from the kernel before fermentation and to either make a biodiesel ourselves or sell it to biodiesel manufacturers,” said Wortzman.

“Many plants in North America are now incorporating this technology because it’s another opportunity to generate a co-product revenue stream from a single kernel of corn.”

In an effort to reduce energy costs at its Quebec ethanol plant in Varennes, GreenField is currently developing an anaerobic digester that will be located on site and receive organic waste from local South Shore communities. The waste-to-energy system will produce biogas that will be used to offset some of the natural gas consumed at the facility.

John Tenpenny, Editor
jtenpenny@annexweb.com