Anaerobic Digestion—Biogas Plant Applications
By Illig (E. Thomas)
Amidst concerns as interrelated, albeit disparate, as rising coastal temperatures and fossil fuel consumption—and their collective impact on the price of a pound of sockeye salmon—an environmentally progressive energy source is making haste of common waste.
Enter biogas, the bacterial degradation or anaerobic digestion (AD) of biological material in the absence of oxygen (see Biogas). Methane and carbon dioxide combined to produce a renewable fuel source from waste treatment. Biogas now propels Swedish railways and buses, provides smoke and ash-free cooking and lighting for over 2 million Indian kitchens and boosts industrial plant efficiencies in Switzerland. Even an overcrowded Rwandan prison is now powered by biogas reconstituted from inmate fecal matter (see Cyrus Farivar's recent article on Wired.com), effectively reducing fuel costs by some 65% while simultaneously mitigating the pollution of nearby water supplies.
An emergent energy source generated from human or animal waste, boasting lower carbon dioxide emissions than traditional fossil fuels, reduced capital expenditures, no foul odor and the genuine creation of something useful from something inherently useless? In today's maelstrom of decomposing debates over what to do about the economics of environmental housekeeping, AD may indeed provide refreshing alternatives.
Other Rwandan prison biogas links
• Kigali Institute of Science and Technology (KIST) Rwandan prison biogas project 2005 Ashden Award finalist
• 30 June 2005 BBC article Rwanda award for 'sewage' cooking
• A word from Emeka Okafor of the Timbuktu Chronicles