Greenhouse-fed ethanol project receives funding

By Ryan C. Christiansen | October 06, 2008
Web exclusive posted Oct. 24, 2008 at 10:02 a.m. CST

EthosGen LLC, a three-year-old business venture incubated by King's College in Wilkes-Barre, Pa., has secured a $1.2 million U.S. Department of Defense contract to study the feasibility of using greenhouses at or near an ethanol plant to grow a sorghum-family hybrid crop for the production of ethanol. With the estimated cost of fuel in the field for the military at approximately $90 per gallon, Greg Emery, a King's College faculty member and an EthosGen business partner, said the goal is to find a way to reduce the cost of making fuel, transporting fuel, and protecting military fuel supply chains.

"We think that an acre of greenhouse can produce probably—at least—50 times the amount of fuel that a similar acre outdoors can produce," Emery said. "In a greenhouse you'll get multiple growing seasons, whereas these plants are really only grown in one season outdoors."

Emery could not identify the specific feedstock, however, he called it was a hybrid from the sorghum family that has been dubbed "C4." EthosGen has been working with Cornell University in Ithaca, N.Y., to develop the hybrid, which has been bred to maximize the amount of fermentable juice that can be extracted from the plant when it's crushed. Growing the plant in a greenhouse means the hybrid can be bred for maximum yields under specific climate conditions and doesn't have to be weather-tolerant, Emery said.

The greenhouse process produces higher yields, in part, Emery said, because the plants don't have time to degrade after harvest. "When you grow these similar plants outdoors," he said, "as soon as you cut the plant it starts to degrade in a matter of minutes and hours. But in a greenhouse, you rotate the crop as it matures to the harvesting point and, the instant that it is harvested and crushed, it immediately is dumped into a fermentation tank, where it is stabilized and fermentation starts; so you get a much, much higher yield of fermentable fluid out of the plant than if you did it comparably out on farmland." The feedstock being used doesn't have to be heated after it's crushed in order to aid fermentation and the byproduct from the crush can be pelletized to be used as heating fuel for the greenhouse, Emery said.

"One of the important aspects of using a greenhouse means that you can put it just about any place in the world (including non-arable land)," he said. "For example, we're growing the plants here in a fairly northern climate in Pennsylvania, but it means that the majority of the transportation costs that are involved with growing a crop and taking it to a centralized ethanol plant, producing it, and then shipping it out hundreds or thousands of miles in different directions, can largely be overcome if you're able to grow the cop right at the source where you're going to blend it into gasoline."

EthosGen currently has two seven-acre greenhouses growing feedstock at Van Hoekelen Greenhouses Inc. in McAdoo, Pa. According to Emery, EthosGen plans to have the new pilot-scale greenhouse facility ready under the Department of Defense contract within a year. The facility's location has not been determined, he said.