Bio-Terre Systems has developed a new low-temperature anaerobic digestion system for processing farm manure and other organic wastes.

DGH Engineering president Dennis Hodgkinson told those on hand for Hog and Poultry Days 2010 in Winnipeg the Bio-Terre process was developed in Canada about 15 years ago is built around culturing a special group of microbial organisms that can function at low temperatures.

Dennis Hodgkinson-DGH Engineering

Anaerobic digestion has historically worked in high temperature ranges, 30 to 35 degrees C for one group of organisms or 50 to 55 degree C for another.

Our technology operates in the range of 10 to 25 degrees Celsius so we have an energy boost.

It shifts the goal posts in terms of the energy required to operate the process.

Because our vessels now operate at lower temperatures, we have energy savings in two respects.

The heat losses are less from our vessels to the environment and more importantly, we need less energy to heat the cold feed stocks up to put them into the process so we have an energy efficiency boost.

Together with the culturing special organisms to work in this low-temperature regime we've wound up with a microbial population that is more robust and more tolerant of changes and imperfections in process control.

As you can imagine, any technology that works on a farm needs to be robust.

Things can go wrong so we need things that are a little more forgiving and this cold temperature process is more forgiving.

Mr Hodgkinson says in converting the organic matter in manure to methane which can be used as fuel the system breaks down about 70 per cent of the solids and it renders the manure odourless.