The Back to the Future movies showcased many creative ideas that tickled the brains of modern engineers. For example, would it really be possible invent a hover board? Future Horizons, Inc. thinks so.
My favorite device was Mr. Fusion. When Doc Brown needed fuel for his time-traveling DeLorean, he simply fed a bunch of organic waste into this tiny energy device. Presumably Mr. Fusion broke down the waste into hydrogen, which fired a thermonuclear fusion reaction to generate energy. The intricate details, of course, are left to the imagination.
The March edition of Mechanical Engineering Magazine includes an interesting note entitled Refining Trash. This piece describes ongoing work at Purdue University to create a portable organic-waste-fired generator for the Army.
It’s not Mr. Fusion, but it’s the next best thing.
Invented by Professor Michael Ladisch and a team of Purdue researchers, the so-called “tactical biorefinery” allows soldiers to convert waste into power in the field. The system is portable by Army standards, roughly the size of a small moving van. Organic waste is fed into the system, which separates food material from residual trash. Food waste is fermented into ethanol. Residual materials (paper, plastic, Styrofoam, and cardboard) are sent to a gasifier to make low-grade propane gas and methane. The gas and ethanol are then combusted in a diesel engine to produce electricity.
While it won’t be sending any DeLoreans 20 years into the future, the tactical biorefinery can certainly reduce the volume of waste generated by military units in the field. If fielded by the military it would also reduce the volume of fuel carried by these units. In addition, the inventors foresee several civilian applications including turning debris into emergency power in disaster areas and provision of supplemental power for restaurants producing food waste.