Collected biogas can be used for process heating, electrical and steam generation, and transportation. A rule of thumb for electricity production is one kilowatt (kW) for every seven to 10 cows.
Odor and fly control. Bacteria in the digester significantly reduce odor-causing compounds. In addition, fly eggs are killed during anaerobic digestion, reducing this disease-causing pest.
Pathogen control. Pathogens like E. coli, Salmonella and Cryptosporidium can’t survive the high temperature of a heated digester.
Disposal. Anaerobic digestion destroys more volatile organic compounds and produces more gas than aerobic digestion does (65 per cent to 75 per cent of volume), resulting in less solid waste.
Environmental. Where animal manure is stored in pits or lagoons, methane is released into the atmosphere. An anaerobic digester reduces the damaging effects of methane, which is 21 times more potent than carbon dioxide in causing global warming.
So why are we still dumping 50 to 60 million tons of manure upon the land here in Alberta? In one area hog manure is trucked to a landfill site and buried guaranteeing that all the surrounding ground water is polluted.
The benefits of processing all farm animal waste in an anaerobic digester are many including environmental, perhaps even human waste could be added to the process.
Frederick Peitzsche, Innisfail