Portable Generator Turns Trash into Electricity

Resource, Apr 2007

Ag engineers from Purdue have created a portable refinery that efficiently converts food, paper, and plastic trash into electricity. The machine, designed for the U.S. military, would allow field soldiers to convert waste into power and could provide civilian applications.

The "tactical biorefinery" processes several kinds of waste at once, converting it into fuel via two parallel processes. The system then burns the different fuels in a diesel engine to power a generator.

ASABE member Michael Ladisch, project leader and professor of agricultural and biological engineering at Purdue University, says the machine's ability to burn multiple fuels at once, along with its mobility, make it unique.

Roughly the size of a small moving van, the biorefinery could alleviate the expense and danger associated with transporting waste and fuel. It could also protect military units by destroying clues that garbage remnants provide.

The portable refinery first separates organic food material from residual trash, such as paper, plastic, Styrofoam, and cardboard. The food waste goes to a bioreactor where industrial yeast ferments it into ethanol. Residual materials go to a gasifier where they are heated under low-oxygen conditions and eventually become low-grade propane gas and methane. The gas and ethanol are then combusted in a modified diesel engine that powers a generator to produce electricity. The prototype produced nearly 90 percent more energy than it consumed during testing.

For more information, contact Ladisch, ladisch@purdue.edu.

ASABE member Nathan Mosier works with the tactical biorefinery, which is designed to convert waste into electricity. (Photo courtesy of Purdue University)