Method, process and system for recycling an asphalt-based roofing material
The present disclosure provides a method, process and system for recycling an asphalt-based roofing material. In particular, the method, process and system are capable of removing and recovering an aggregate product, fiber product and an asphalt product from the asphalt-based roofing material. The aggregate, fiber and asphalt products each may be reused in a variety of applications.
1. A method for removing aggregate from an asphalt-based roofing material comprising:
(a) contacting the asphalt-based roofing material with at least one pressurized stream of fluid to mechanically separate the aggregate from the asphalt-based roofing material; and
(b) agitating or pulsing the separated aggregate, asphalt-based roofing material and fluid in a separation tank to remove the separated aggregate from the asphalt-based roofing material and fluid by density.
2. The method of claim 1 , wherein the asphalt-based roofing material is contacted with the at least one pressurized stream of fluid within the separation tank or externally in a separate vessel.
3. The method of claim 1 , wherein the asphalt-based roofing material is contacted with at least two pressurized streams of fluid.
4. The method of claim 3 , wherein the at least two pressurized streams of fluid are opposed to one another.
5. The method of claim 1 , wherein the fluid comprises water.
6. The method of claim 5 , wherein the fluid is at ambient temperature.
7. The method of claim 1 , wherein the asphalt-based roofing material is pretreated to crush or grind the asphalt-based roofing material.
8. The method of claim 1 , further comprising the step of recovering the separated aggregate.
9. The method of claim 8 , wherein at least about 90 wt. % of a total weight of aggregate originally present in the asphalt-based roofing material is recovered as separated aggregate.
10. A method for separating fiber from an aggregate-free asphalt-based roofing material, the method comprising:
(a) mixing the aggregate-free asphalt-based roofing material with a solvent to form a slurry; and
(b) machine pressing or filter pressing the slurry in a fiber separator to separate fiber from the slurry and produce an asphalt/solvent mixture and a fiber product,
wherein the aggregate-free asphalt-based roofing material was obtained by contacting an asphalt-based roofing material with at least one pressurized stream of fluid to remove substantially all aggregate from the asphalt-based roofing material.
11. The method of claim 10 , wherein the solvent is selected from an aromatic solvent, an aliphatic solvent, an alcohol, an ether, a ketone, carbon disulfide and a mixture thereof.
12. The method of claim 11 , wherein a mass fraction of solvent mixed with the aggregate-free asphalt-based roofing material is in a range of about 15-50 wt. % relative to the total weight of the slurry.
13. The method of claim 10 , wherein the fiber separator is a rotary press, a belt press, a hydraulic press, a piston press, a hydrocyclone or a screw press.
14. The method of claim 10 , wherein the aggregate-free asphalt-based roofing material was obtained by contacting an asphalt-based roofing material with at least one pressurized stream of fluid to remove substantially all aggregate from the asphalt-based roofing material and drying the asphalt-based roofing material.
15. The method of claim 10 , wherein the fiber product is substantially free of asphalt.
16. The method of claim 1 , wherein the asphalt-based roofing material comprises roofing shingles.
17. The method of claim 1 , wherein the at least one pressurized stream of fluid is directed towards an impact surface.
18. The method of claim 8 , wherein the recovered aggregate is dewatered or dried to remove fluid from the aggregate.
19. The method of claim 1 , further comprising the step of recovering an asphalt-fiber slurry from the separation tank.
20. The method of claim 19 , wherein the asphalt-fiber slurry is dewatered or dried in a drying apparatus to remove fluid from the asphalt-fiber slurry and produce an aggregate-free asphalt-based roofing material.
21. The method of claim 20 , wherein the drying apparatus is a vacuum dryer, tray dryer, fluidized bed dryer, rotary dryer, dewatering screen, spray dryer, centrifuge or a hydrocyclone.
22. The method of claim 20 , wherein at least about 70 wt. % of a total weight of fluid originally present in the asphalt-fiber slurry is removed.
23. The method of claim 20 , wherein the fluid removed from the asphalt-fiber slurry is recycled in the at least one pressurized stream of fluid or the separation tank.
24. The method of claim 10 , wherein the aggregate-free asphalt-based roofing material is a dewatered or dried to remove moisture from the aggregate-free asphalt-based roofing material.
25. The method of claim 10 , wherein steps (a) and (b) are performed at ambient temperature.
26. The method of claim 10 , wherein the fiber product comprises less than about 20 wt. % of asphalt.
27. The method of claim 10 , wherein the solvent comprises toluene.