Chemistry
february 2015
BY annie chang
Biobatteries
source
Be Sustainable Magazine
4
Turning Industrial Waste into
Electricity and Fertilizer
Today renewable sources cover a fifth of the world's energy needs. Scientists have long been in search of a technology that does not depend on fluctuating wind and solar energy. Researchers from the Fraunhofer Institute for Environmental Safety and Energy Technology in Germany have succeeded in developing such a technology, the biobattery.
The biobattery is modular and consists of eco-friendly technologies such as biogas plants, thermal storage, carburetors, and engines. The biobattery, however, can process only a limited number of organic substances. The raw materials that enter the system, such as animal excrement, sewage sludge, scrap wood, or straw, first pass through an anaerobic channel. There the material is heated up and broken down into solid residue char (biochar) and volatile gases. The gases that are reheated and cooled down condense into a liquid, which contains a high-quality oil and water.
The biobattery produces oil, which can be processed as engine fuel; gas, which can be fed back into the plant; and biochar, which can be used as a fertilizer. Not only does the biobattery process generate electricity and heat, it also produces high quality gas, oil, and carbon. "The particular advantage of the biobattery is that we can utilize a number of raw materials which would otherwise have to be disposed of often at great cost," explains Professor Andreas Hornung, Director of UMSICHT at the Institute Branch in Sulzbach-Rosenberg.