What is biogas?

Biogas is the result of the controlled microbial breakdown of organic materials such as animal manures or food scraps in an anaerobic digester. An anaerobic digester is operated at a controlled temperature, pH and loading rate to encourage the growth of microorganisms that eat the organic matter and produce biogas and a more biologically stable liquid effluent. Biogas is a mixture of about 60-70% methane (natural gas), 30-40% carbon dioxide and other trace gases, such as hydrogen sulfide. The heat content is based on the amount of methane and is about 600 BTUs per cubic foot.

Are biogas/anaerobic digesters a realistic investment for today's dairies?

Digester technology has advanced to a point where we are able to utilize already developed modules in a cost effective manner on your farm. Anaerobic digesters, along with electricity generation and saleable end product biosolids, allow animal production enterprises to become neighborhood and environment friendly, as well as producing another revenue flow. The technology is already in place to significantly reduce soil nutrient loading and methane gas negatives from animal production.

How large a dairy must I have to even consider such a biogas system?

With the systems and technology developed by leading digester technology providers the logical biogas plant adopters now are farms at/or approaching 800 cows or larger. (Dry cows and springing heifers are .5 equivalents per head, and young growing stock from 350 lbs. to springing are .25 equivalents per head). Systems for dairies under 800 cow level are possible, but need evaluation on a farm by farm basis as cost effectiveness. No farm or combinations of farms is ever too large for such a system.

Is this the right time for you to consider a biogas system?

We are more than willing to discuss your situation and provide preliminary budget numbers based on key data about your farm, and also by running a few laboratory tests on the manure. By comparing the budget costs to potential earnings from generated electricity sales and from end product bio-solid sales, the economic return period for your situation can be estimated.

Is biogas plant dangerous? What distance to buildings and residential area from biogas plant should be?

A biogas plant improves the environment better and is not dangerous. It can be placed near production facilities. As to power transmission lines and roads distance should be ideally about 30 metres, but can be much less.

Equipment is fitted to climate conditions. Bioreactors have thermal insulation and are heated by heating (cooling) system. In cold winter biogas plant consumes up to 50% of produced heat power. But this power comes from generator cooling and of secondary nature.

Besides biogas, what comes out of the digesters?

The liquid that results from the anaerobic digestion process has solids which are separated out, composted, and sold to local gardeners, landscapers and farmers. Some farmers use the solids as bedding for their cows and sell it as bedding to neighbors. The liquids are returned to the farmer as nutrient rich natural fertilizer, which replaces imported nutrients and thereby cuts costs.

Does a biogas facility smell?

Actually, anaerobic digesters alleviate odor problems, especially as suburban growth surrounds farms and introduces neighbors who complain about manure smells. By installing an anaerobic digester, the farmer solves odor issues to everyone's satisfaction. Since the digesters are airtight, the smell stays within, and the liquids and solids coming out of the digester have only a very slight odor compared to raw slurry.

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