Energy contained in the manure is captured in the form of methane, and this methane is used to dry the harvested minerals in the production of a high-quality fertilizer. Their system avoids having to generate and market electricity, two steps that are major obstacles for conventional digesters. It also makes the energy cost of this system relatively small, especially if good separation of minerals and water can be achieved by using the freeze-thaw process powered by Mother Nature.

Another benefit of the system is that its end product, fertilizer with a composition of 12-8-8, is not a niche product and is easily marketed. Many methods of producing value-added products from animal manure target niche markets, which may work for smaller operations. But if a large portion of the swine industry were to adopt such value-added technology, the market would quickly become saturated, and the price of the end product would plummet.

Because the Crystal Peak system uses a freeze-thaw process, it will be suitable only for climatic zones were winter temperatures fluctuate from substantially below freezing to above freezing. In North Carolina, alternative methods for separating minerals from the liquid fraction would have to be applied (evaporation of the water may be a better option here). However, the system is a very intriguing solution to swine manure disposal, and it will be interesting to see how it operates in practice.

Reproduced Courtesy

Source: North Carolina State University Swine Extension - April 2004