Landscape waste recycling process to power city fleet
By Susan Frick Carlman email@example.com October 29, 2011 9:38PM
COD student Rob Gibson stands in front of the gasifier prototype at Packer Engineering. | Courtesy of Rich Malec/College of DuPage)
The city website provides comprehensive details about the Green Fuels Depot project. Find it at www.naperville.il.us/greenfuelsdepot.aspx.
Updated: December 1, 2011 8:02AM
Ever wonder what becomes of all the branches, twigs, leaves and other yard debris you set out at the curb, after the trucks come and haul it all away? They have a new calling, as part of a locally grown energy source — literally.
The first phase of the local partnership working toward collecting yard waste and converting it into fuels is poised to go live in the coming weeks. In the works for nearly three years, the Green Fuels Depot is expected eventually to offer an alternative energy source with the potential to attract worldwide interest.
“The project is about done,” said Al Wilks, senior director of research and development at Packer Engineering in Naperville, lead entity in the collaborative undertaking that also involves Argonne National Laboratory, the city of Naperville and College of DuPage.
The partners have devised a process that eventually will generate ethanol- and hydrogen-based fuels and electric power, leaving a carbon byproduct that has agricultural applications. Because federal funding was reduced after the project began, the first two objectives haven’t yet been reached yet, but the Green Fuels Depot is nearly ready for its close-up. Wilks said planners are aiming for a Nov. 14 unveiling, complete with a display of what the system can do.
Using brush collected last spring, one demonstration will show how the equipment generates hydrogen, which can be used to power zero-emission hydrogen cars, and another will exhibit the production of ethanol, which goes into E85 vehicle fuel.
Full production of the two fuels was delayed when funding cuts reduced the project from three years to one. The third product of the process, electricity, is ready for production now.
“We had to make some adjustments in what we were doing, but we wanted the demonstrations to be there,” Wilks said.
When it is fully operational, the ethanol produced by the depot will be used to run the city’s fleet of flex fuel vehicles.
“It’s a utopian vision to have this closed loop circuit, where a city can turn its own yard waste into fuels that will benefit their community,” said Argonne vehicle testing activities manager Glenn Keller in TransForum, a publication produced by the U.S. Department of Energy facility’s Center for Transportation Research.
Argonne researchers calculated that the 48,000 cubic yards of landscape waste generated in the city would be enough to run 300 flex fuel vehicles.
Jim Inglese, fleet services manager, said the city sold part of the fleet, which once numbered about 30, after staff reductions eliminated the need to keep them all. And currently, logistical concerns leave the remaining vehicles running just on regular gas. Existing sources of E85 fuel are too far away, and the fuel now is too inefficient and costs too much, to make it a practical choice.
“I still have flex fuel (vehicles), even though we don’t purchase ethanol currently,” Inglese said. “The energy content of the ethanol fuels is much lower than regular fuel, so we would burn more of it.”
He expects the new fuel will be significantly less costly than E85, and said he’s drawn by the eventual mechanics of the project.
“The more aggressive ethanol is going to have to be dispensed and stored, and I’m interested in seeing how that will work,” Inglese said.
Warrenville resident Rob Gibson also is intrigued by the process. An electro-mechanical technology major at COD, Gibson was involved in the depot project when he worked at Packer through an internship over the past summer. He said one reason he was attracted to the environmentally benign fuel production system was his concern about reducing U.S. dependence on imported energy.
On a web page devoted to the project, the city likens the generation mechanism — known as a gasifier, and nicknamed the Stalk Stoker — to a self-cleaning oven. Using high heat, the device can accelerate the decomposition of leaves, grass, branches and other organic materials to produce syngas, which is captured and converted into ethanol, electricity or hydrogen. A non-toxic black char material left after the syngas has been harvested will be suitable for amending soil as a fertilizing agent.
Emissions are limited to water vapor and carbon dioxide, at levels that comply with federal limits, planners say.
“The water vapor may appear white on cold days,” the city says on its website. “The white vapor is not smoke, it is what comes out of a tea kettle.”