Research conducted by the University of Manitoba has shown adding the right amount of glycerol to swine manure can double biogas production during anaerobic digestion.
Anaerobic digestion is a natural process under which bacteria break down organic wastes producing a range of compounds, including methane which can be used as a source of energy.
Researchers with the University of Manitoba have completed a one-year study in which the biogas production of swine manure was compared to that of swine manure amended with glycerol.
Masters graduate Oswald Wohlgemut explains glycerol, a byproduct of several industrial processes including biodiesel production, has little value in its unrefined form but it’s easily broken down and can benefit the anaerobic digestion process.
Essentially we were testing the chemical characteristics of the digested manure with and without glycerol along with the gas production.
Samples were collected approximately three times a week and gas production was recorded daily for approximately a year while the experiments were being run.
We compared the swine manure that was digested and we compared it with swine that was digested with one per cent, two per cent and four per cent glycerol addition.
The addition of one per cent glycerol by volume to the swine manure essentially doubled the methane production and remained stable throughout the life of the experiment.
While we were adding the two per cent and the four per cent glycerol, it caused failure of the anaerobic digestion process.
Wohlgemut says glycerol is of particular interest because of the anticipated increase in biodiesel production in Manitoba and the expected surplus of glycerol.
He says the work suggests farmers throughout North America who use anaerobic digestion to produce energy can use glycerol at low doses to enhance methane production and if glycerol is available locally it can be very viable.
Source: Farmscape.Ca
