The food you scrape off your plate — and, more importantly, the tons of leftover, unused and wasted food dumped into landfills every day — can be turned into an environmentally friendly fuel, three Purdue University professors have found.
The three — Robert Kramer and Libbie Pelter, at Purdue’s Northwest campus in Hammond, and John Patterson, at the West Lafayette campus — have developed a process to produce hydrogen, a clean-burning fuel, from food waste.
“We take garbage and make something useful out of it,” said Kramer, the principal researcher in the project. “So rather than having it as a disposal cost, it becomes a resource. Rather than having a negative value, it becomes a positive value.”
Billions of dollars worth of food is wasted in the United States every year, the U.S. Department of Agriculture has said, and the waste rotting in landfills creates methane, a much more potent greenhouse gas than carbon dioxide in warming the atmosphere.
“Now we’re basically throwing away all those millions of dollars every year,” Kramer said. “And the question is, is there some way we can recoup some of that value? That’s what we’re looking at.”
The researchers have combined their backgrounds in different disciplines — Kramer in physics, Pelter in chemistry and Patterson in animal sciences — for their project to isolate hydrogen from biological materials.
They started about 10 years ago looking at sewage as a source, and then worked on producing hydrogen as a byproduct of making ethanol.
“After a while, I just looked at this and said, can we try this with food waste?” Kramer said.
He said the process they developed produces hydrogen efficiently enough to be used in industries, in vehicles, and for generating electricity.
One of its positive aspects, Kramer and Pelter said, is that it uses much less energy to create fuel from waste than other processes, such as those that require high temperatures in reactor vessels to break down waste into synthetic fuel.
Another advantage of their process, they said, is that the waste product, after the hydrogen has been extracted, can be used as a fertilizer.
“This process has been kind of fun,” Kramer said, “in that very often we try things and get very positive results out of it.
“In our process, we don’t use highly purified water. We use good old tap water. So it’s kind of intriguing. We actually get more productivity by using tap water than we would by using de-ionized water. That’s part of the appeal of the process, that it’s not so sensitive to strict laboratory conditions.”
The work has been funded over the years by $800,000 in grants from the U.S. Department of Energy and the Purdue Research Foundation. Two patents have been issued so far, and a third is in the final stages of approval.
The process now is confined to a 2 1/2-gallon glass vessel in a basement laboratory on the Hammond campus.
On a recent day, a yellowish liquid mixture derived from oatmeal, corn and mixed vegetables spun slowly inside the vessel while instruments measured and analyzed the amount of hydrogen coming off the liquid.
This summer, the researchers will start using a much larger vessel, with 50 gallons capacity, in another area of the Purdue lab, to process the food waste.
And with the results of that work, they hope to begin industrial scale-up early next year.
The Purdue Research Foundation has reached a licensing agreement with an international energy company to produce hydrogen commercially with the Purdue process.
Another licensing agreement is being negotiated with a company in Indiana.
The names of those companies can’t be disclosed now, the Purdue announcement said.
“We think we’re developing designs now that will be cost-effective and will be easy to operate and will produce hydrogen in a short period of time,” Kramer said.
“And of course, hydrogen is almost the ultimate fuel, because when you burn hydrogen you get water vapor and that’s it.”
Hydrogen is the most abundant element on earth but doesn’t exist by itself in nature. Huge amounts of hydrogen are produced every year, much of it from natural gas.
Hydrogen is most commonly used in petroleum refining and fertilizer production, according to the U.S. Department of Energy, but uses are being developed in transportation and utilities.
When used in a fuel cell, hydrogen produces only heat, electricity and water.
“What’s different is that we’ve produced it from waste – garbage, basically – and will be using it as an energy carrier for a variety of purposes,” Kramer said.
“We’re hoping to contribute somewhat to the energy balance of the world. We’re not going to solve all the problems. We’re hoping to at least make some positive contribution.
“All over the world, huge amounts of food are wasted. And now, rather than discarding it, we think there’s a way to produce some positive value from it.”
Tim Zorn is a freelance reporter for the Post-Tribune.
