Organics recovery from dry fraction
Solid waste, for example source separated organics (SSO) or commercial and industrial (C&I) waste or both, are treated by first pressurizing the waste against a screen to produce a solids fraction and a liquid fraction. The liquid fraction can be treated in an anaerobic digester. The solids fraction is pulverized or milled, for example with a hammer mill, preferably after being diluted. The pulverized or milled waste is separated again to provide a second solids faction and a second liquid fraction. The liquid fraction can be treated in an anaerobic digester. The solids fraction is primarily inert and can be landfilled, preferably after being washed.
1. A method of treating solid waste including organic material, the method comprising steps of,
a) extruding or pressing the waste to separate a dry fraction from a wet fraction;
b) diluting the dry fraction with water of digester filtrate;
c) pulverizing or milling the diluted dry fraction, and separating the pulverized or milled diluted dry fraction into (i) a liquid fraction that includes residual organics and (ii) dry fraction rejects by passing the pulverized or milled diluted dry fraction to a screen that retains the dry fraction rejects and permits the passage of the liquid fraction while or after pulverizing or milling the diluted dry fraction; and
d) washing the separated dry fraction rejects to remove organic film or organics.
2. The method of claim 1 wherein the wet fraction is treated in an anaerobic digester.
3. The method of claim 1 wherein the residual organics are treated in an anaerobic digester.
4. The method of claim 1 wherein wash water produced from washing the dry fraction rejects is treated by anaerobic digestion.
5. The method of claim 1 , wherein extruding or pressing the waste is performed at a pressure from 50 to 180 bar.
6. The method of claim 1 , wherein the wet fraction comprises over 80% of the organic material.
7. The method of claim 6 , wherein the wet fraction comprises over 90% of the organic material.
8. The method of claim 1 , wherein the solid waste is: source separated organics, commercial waste, industrial waste, or any combination thereof.