Cutting Water Content Improves Anaerobic Digestion
CANADA - A Manitoba engineering firm believes that reducing the water content is the key to economically processing swine manure using anaerobic digestion, writes Bruce Cochrane.Brandon-based Samson Engineering is developing one of several Manitoba research projects intended to demonstrate the use of anaerobic digestion to manage swine manure.
An anaerobic digester, being built at Riverbend Colony Farms near Carberry, will produce biogas, a mixture of gases including methane, which can be burned to create energy.
Civil Engineer Phil Dorn says, in addition to producing a fuel which can be used on the farm, anaerobic digestion addresses concerns related to pathogens and nutrients in the manure and odour.
Phil Dorn-Samson Engineering
What we do initially is reduce the size of the problem by doing some really unique de-watering scenario whereby water can be recycled into the barn and re-consumed so, right away, we take the problem down to a quarter of what it would be.
Then secondly we take that concentrate and we digest it anaerobically and thereby we address some of the nutrient issues, some of the pathogen issues, some of the solid issues and also, with respect to that, you get a substantial amount of gas production.
Then, in the final analysis, the digestate that comes out is very valuable quite frankly and what it's valuable for is particularly in the organic food crops because what do you put on organic food crops as fertilizer?
Well this happens to be organic fertilizer which can be concentrated and shipped to areas where organic food crops are being grown and it's very very good so this is what we're trying to do.
Dorn says the system being developed near Carberry will be used for direct heating on the farm or secondarily for the production of electricity.
He notes there is a large demand for heat and electricity on the farm and it's a question of how to best utilize that energy.