Energy integrated farm operation with recovery of animal feed from food waste

Abstract

A method of operating an energy integrated farm operation with recovery of animal feed from liquid food waste is described and claimed. The method involves extracting methane gas from animal manure and using the methane gas to power an electrical generator. The electricity from the generator and the methane gas itself may be used to operate a dryer. The dryer is used to dry a liquid food waste stream to yield a dry food product. The dry food product recovered has enough nutritional value to be useful as animal feed.

What is claimed is:  
     
         1 . A method of operating an energy integrated farm operation with recovery of animal feed from liquid food waste, comprising 
 providing farm animals;    providing liquid food waste;    wherein said farm animals produce manure;    wherein said manure is processed in a digester such that methane gas is produced, and    wherein at least some portion of the methane gas produced is used to generate electricity;    the improvement comprising that both, or either of, the methane gas produced by the digester and the electricity produced by the methane gas are used to power a dryer that is used to dry said liquid food waste;    wherein the dried food waste is collected for use as animal feed; and    wherein optionally at least some of the liquid food waste is contacted with bentonite clay and an anionic polymer prior to the liquid food waste being dried in the dryer.    
     
     
         2 . The method of  claim 1  in which said farm operation is a dairy farm.  
     
     
         3 . The method of  claim 1  in which said liquid food waste is liquid food waste from a dairy manufacturing plant.  
     
     
         4 . The method of  claim 1  in which said liquid food waste is contacted with bentonite clay and an anionic polymer prior to the liquid food waste being dried in the dryer.