Does anyone have experience with drying and pelletizing animal waste? What type of value as fertilizer would this have? I suppose you run it through a screw press to get the water out and then pelletize and dry? Please advise.
In the mid 1970's, I had a summer college job at a golf course where they fertilized the greens with a product called Milogranite (sp?), reportedly a human sewage waste product, sanitized to a degree that it was commercially available in 50 pound sacks. It was not pelletized but more of a bulk clumpy powdery substance.
I can't recall its fertilzer rating'. But I suspect a sample provided to a lab would get you results of its component values.
What types of animal waste are you concerned with? Typically animal manures contain only small amounts of the 'big three' plant nutrients; N, P, and K. Composted chicken manure (dried slowly to retain the elements) typically contains the best analysis at about 2.8-2.8-1.5 (except guano of course). Other manures are in the 1-1-1 range and even less when not dried. These values are considered very low as far as nutrient value is concerned and it would likely be more profitable to sell the manure as is than to process it and sell a granulated or pelletized version.
This aside, there are several small organic fertilizer granulation plants in operation in the US. These typically use Chicken manure as a main ingredient and add other natural ingredients to raise the nutrient content. This fertilizer obtains a premium amount per nutrient because it is organic and it typically contains many micronutrients compared to chemical fertilizer.
This granulation process is preferred because it produces a better quality product and allows more ingredients to be successfully added. It is typically produced in greens grade, turf grade, and agricultural grade, although golf course varieties are usually worth the most.
Years ago larger chicken farmers (Purdue is the main one I am thinking of) did install pelletizer process plants because they were producing such a large excess of hen wastes. I do not believe the manufacturer of these plants is still in business as it was only made profitale for environmental reasons (Purdue was having trouble getting rid of raw waste).
There is a company nearby which burns turkey litter and then forms the ash into fertilizer granules. At that point the nitrogen is gone, leaving potash, maybe some phoshate?. This is a bypoduct, electricity generation being the main objective.