Organic containing sludge to fertilizer alkaline conversion process
This invention is directed to systems, devices and methods for treating organic-containing sludges and converting such sludges to high value fertilizers containing both inorganic and organic fertilizer components, which creates an inorganically-augmented bioorganic fertilizer. The invention describes methods to create a thixotrophic or paste-like material via the application of mixing energy to the organic sludge followed by an alkaline treatment and a subsequent ammoniation. The invention further describes a method to increase the plant nutrient content in the organic containing product to a level which permits the finished granular fertilizer product to compete in the commercial agricultural fertilizer marketplace. Further, the invention reduces odors associated with said organic-containing sludges.
1. A process of fertilizer manufacture comprising:
creating a thixotropic paste from a composition containing biosolids;
adding an oxidizing agent to the paste;
adding an alkaline agent to the paste to produce a pH of 10 or higher;
exposing the paste to ammonia at a concentration of at least 1,000 ppm;
adding an acid to the paste to produce heat and a pH 7.0 or less;
adding a granulating agent to the paste;
extruding or granulating the paste; and
drying the extruded or granulated paste to a dryness of 90% or more of solids.
2. The method of claim 1 , wherein the biosolids are selected from the group consisting of municipal biosolids and sludges, manures and animal residuals, lagoon sludges, organic-containing sludges produced from food fermentation, sludge waste products, pharmaceutical fermentation waste, industrial fermentation products, and mixtures and combinations thereof.
3. The method of claim 1 , wherein the oxidizing agent is selected from the group consisting of hypochlorite, sodium hypochlorite, calcium hypochlorite, iron oxide, metal oxide, calcium ferrate, potassium ferrate, sodium ferrate, oxygen, hydrogen peroxide, peroxide, ozone, chlorine dioxide, and combinations thereof.
4. The method of claim 1 , wherein the alkaline agent is selected from the group consisting, of calcium oxide, calcium hydroxide, potassium hydroxide, sodium hydroxide, alkaline by products, cement kiln dust, lime kiln dust, Class C fly ash, Class F fly ash, lime-injected fly ash, and alkaline materials, and combinations thereof.
5. The method of claim 1 , wherein, after addition of the alkaline agent, the mixture is pH 11 or higher.
6. The method of claim 1 , wherein the ammonia is aqueous or anhydrous ammonia.
7. The method of claim 1 , wherein the concentration of ammonia is at least 5,000 ppm.
8. The method of claim 1 , wherein the concentration of ammonia is at least 10,000 ppm.
9. The method of claim 1 , wherein the concentration of ammonia is at least 20,000 ppm.
10. The method of claim 1 , wherein the exposure is for at least 30 seconds.
11. The method of claim 1 , wherein the exposure is for at least 2 minutes.
12. The method of claim 1 , wherein the exposure is for at least 5 minutes.
13. The method of claim 1 , wherein the concentration of ammonia provides a dry weight nitrogen concentration of 6%.
14. The method of claim 1 , wherein the concentration of ammonia provides a dry weight nitrogen concentration of 10%.
15. The method of claim 1 , wherein the concentration of ammonia provides a dry weight nitrogen concentration of 14%.
16. The method of claim 1 , wherein, after addition of the alkaline agent, the mixtures is pH 11 or higher.
17. The method of claim 1 , wherein the acid is phosphoric or sulfuric acid.
18. The method of claim 1 , wherein the concentrated acid is selected from the group consisting of phosphoric acid, sulfuric acid, sulfamic acid, hydrochloric acid, nitric acid and combinations thereof.
19. The method of claim 1 , wherein, further treating with the acid, the paste is pH 7.0 or less.
20. The method of claim 1 , further comprising blending a plant nutrient with the thixotropic paste to increase nitrogen, phosphorus and iron levels.
21. The method of claim 20 , wherein the plant nutrient content is at least 8% nitrogen by dry weight.
22. The method of claim 20 , wherein the plant nutrient content is at least 12% by dry weight.
23. The method of claim 20 , wherein the plant nutrient content is at least 15% by dry weight.
24. The method of claim 1 , wherein odor associated with the paste is reduced.
25. The method of claim 1 , wherein the thixotropic paste is treated with an oxidizing agent such that odorants emission is reduced simultaneously with increasing plant nutrient concentration.
26. The method of claim 1 , wherein the extruded paste is formed into pellets or granules.
27. The method of claim 26 , wherein the pellets or granules are coated.
28. The method of claim 1 , further comprising storing the dried paste in a dry environment.
29. The method of claim 1 , further comprising applying the dried paste to plants as a fertilizer.
30. The method of claim 1 , further comprising applying an antimicrobial stress during any step.
31. The method of claim 30 , wherein the microbial stress is selected from the group consisting of a pH greater than pH 10, a pH greater than pH 11.0; free ammonia concentration in the paste at greater than 1,000 ppm, free ammonia, concentration in the paste at greater than 10,000 ppm; free ammonia concentration in the paste at greater than 15,000 ppm; heat at greater than 80° C.; greater than 100° C., heat at greater than 121° C. and combinations thereof.
32. The method of claim 1 , further comprising adding a fertilizer to the dried pellets or granules to provide nutrient enhancement.
33. The method of claim 32 , wherein the fertilizer is selected from the group consisting of dry fertilizers, liquid fertilizers, ammonium sulfate, ammonium nitrate mono-ammonium phosphate, di-ammonium phosphate, urea, urea ammonium nitrate (“UAN”), liquid urea, liquid N-P-K fertilizers, 16-4-8, 10-8-8, 6-14-6, and combinations thereof.