Process for recovering nutrients from cattle manure

摘要

Shredded manure is soaked in an excess of water to form a basic slurry which is then separated in a centrifugal separator. The liquid portion is added to a floc tank where a suitable flocculant precipitates proteins which upon passing through a vacuum filter is heated, producing a dry protein cake. The liquid filtrate from the vacuum filter is added to the autoclave, along with the solid material from the centrifugal separator, and the resulting slurry is acidified and raised to an elevated temperature and pressure for a prescribed time, thereby converting starches to mono-saccharides and amino sugars. The hot acidified slurry from the autoclave is discharged into a settling tank where it is acted upon by calcium oxide, removing sulphates. Subsequent filtering and evaporation of the hot slurry produces a molasses-like syrup including a significant percentage of sugars and some proteins.