Under anaerobic digestion, bacteria break down organic wastes, such as livestock manure, and produce a range of compounds including methane which can be used as an energy source.

Research conducted at the University of Manitoba has shown the addition of glycerol to swine manure at one per cent of the total volume will double biogas production during anaerobic digestion without compromising the process, writes Bruce Cochrane.

Master's graduate, Oswald Wohlgemut, says glycerol is of interest because it's becoming increasingly available and there are few uses for it.

Oswald Wohlgemut – University of Manitoba

What we were attempting to do was to simulate an anaerobic digestion process with swine manure and glycerol.

Glycerol is basically a sugar alcohol.

It can be produced from several different industrial processes such as being a byproduct in the production of biodiesel.

It is as I mentioned a byproduct or a waste product and has little value in its unrefined form however it can be greatly beneficial in the anaerobic digestion process.

It's also of interest because of the anticipated increase in biodiesel production in Manitoba and the expected surplus of glycerol.

Mr Wohlgemut notes, while anaerobic digestion remained stable throughout the experiment with the addition of glycerol at one per cent of total volume, rates of two and four per cent caused failure of the process.

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.