Granted Patent B2

US 8,999,014 · App. 13/891,530 · Granted Apr 7, 2015

Abstract

Claims (43)

1. A method of producing an engineered fuel feedstock from a processed MSW waste stream, the method comprising:

combining a first waste stream that includes at least one of hard plastic, soft plastic and mixed plastic with a sorbent;

increasing the temperature of the combined first waste stream and sorbent to a temperature in a range of about 200° C. to about 400° C.;

combining the thermally treated first waste stream and sorbent with a second waste stream, the second waste stream including fiber; and

compressing the combined first waste stream, sorbent, and second waste stream to form a densified engineered fuel feedstock.

2. The method of claim 1 , wherein the temperature of the combined first waste stream and sorbent is increased for at least about 10 minutes.

3. The method of claim 2 , wherein the temperature of the combined first waste stream and sorbent is increased to at least about 30 minutes.

4. The method of claim 1 , wherein the temperature of the combined first waste stream and sorbent is increased to at least about 350° C.

5. The method of claim 1 , wherein the first waste stream includes a hard plastic and a soft plastic.

6. The method of claim 1 , wherein the second waste stream includes fiber.

7. The method of claim 1 , further comprising:

processing the engineered fuel feedstock to an average particle size of less than about ¼ inch.

8. The method of claim 1 , wherein increasing the temperature of the combined first waste stream and sorbent de-volatizes the constituents of the waste stream.

9. The method of claim 1 , wherein the step of increasing the temperature of the combined first waste stream and sorbent takes place in a heated screw conveyor, rotary kiln, rotary dryer, screw roaster, or other thermal treatment vessel.

10. A method of producing an engineered fuel feedstock from processed MSW waste streams, the method comprising:

heating a first classified waste stream including plastics to a temperature that is above a decomposition point and below an ignition point of the plastics to produce a second waste stream and a gas;

extracting the gas from the second waste stream;

reacting the gas to a less reactive state;

combining the second waste stream with a third waste stream in a predetermined ratio to form an engineered fuel feedstock.

11. The method of claim 10 , wherein the first waste stream includes a chlorinated plastic.

12. The method of claim 10 , wherein the third waste stream includes fiber.

13. The method of claim 10 , wherein the first waste stream is heated to temperature in a range from about 200° C. to about 350° C.

14. The method of claim 10 , wherein the gas includes chlorine.

15. The method of claim 14 , wherein the gas includes at least one of HCl, dioxins, and chlorine gas.

16. The method of claim 15 , wherein reacting the gas to a less reactive state includes reacting the gas with Na3(CO 3 )(HCO 3 ).2H 2 O to form NaCl.

17. The method of claim 10 , wherein the chlorine content of the second waste stream is less than about 500 ppm.

18. The method of claim 10 , wherein the first waste stream includes a sorbent.

19. The method of claim 18 , wherein the sorbent is at least one of sodium sesquicarbonate (Trona), sodium bicarbonate, sodium carbonate, zinc ferrite, zinc copper ferrite, zinc titanate, copper ferrite aluminate, copper aluminate, copper manganese oxide, nickel supported on alumina, zinc oxide, iron oxide, copper, copper (I) oxide, copper (II) oxide, limestone, lime, Fe, FeO, Fe 2 O 3 , Fe 3 O 4 , iron filings, CaCO 3 , Ca(OH) 2 , CaCO 3 .MgO, silica, alumina, china clay, kaolinite, bauxite, emathlite, attapulgite, coal ash, egg shells, organic salts (such as calcium magnesium acetate (CMA), calcium acetate (CA), calcium formate (CF), calcium benzoate (CB), calcium propionate (CP) and magnesium acetate (MA)), urea, calcium bromide, sodium bromide, ammonium bromide, hydrogen bromide, ammonium sulfate, lignosulfonate and Ca-montmorillonite.

20. The method of claim 10 , wherein the first waste stream is about 50% to about 90% by weight of sorbent.

21. The method of claim 10 , wherein the gas includes at least one of plasticizers, diluents, and VOC's.

22. The method of claim 10 , wherein the chlorine content of the second waste stream is less than about 500 ppm.

23. An engineered fuel feedstock produced by the method of claim 1 , comprising:

a plastic content of between about 5 wt. % and about 50 wt. %;

a fiber content of between about 50 wt. % and about 95 wt. %;

a sorbent content of between about 1 wt. % and about 50 wt. %; and

a total chlorine content of less than 400 ppm.

24. The engineered fuel feedstock of claim 23 , wherein the plastic content is between about 10 wt. % and about 30 wt. %.

25. The engineered fuel feedstock of claim 23 , wherein the plastic content is between about 6 wt. % and about 38 wt. %.

26. The engineered fuel feedstock of claim 25 , wherein the plastic content is between about 11 wt. % and about 14 wt. %.

27. The engineered fuel feedstock of claim 23 , wherein the fiber content is between about 70 wt. % and about 90 wt. %.

28. The engineered fuel feedstock of claim 23 , wherein the fiber content is between about 30 wt. % and about 71 wt. %.

29. The engineered fuel feedstock of claim 28 , wherein the fiber content is between about 44 wt. % and about 56 wt. %.

30. The engineered fuel feedstock of claim 23 , wherein the sorbent content is between about 23 wt. % and about 40 wt. %.

Assignments (9)