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 recovering an asphalt product from an asphalt/solvent mixture comprising:
(a) preparing the asphalt/solvent mixture by mixing a substantially de-aggregated asphalt-based roofing material with a solvent;
(b) passing the asphalt/solvent mixture through a solvent separator to separate the asphalt product from the solvent; and
(c) removing the asphalt from the solvent separator,
wherein the asphalt in the asphalt/solvent mixture was derived from an asphalt-based roofing material and is substantially free of aggregate and fiber.
2. The method of claim 1 , wherein the solvent separator is a distillation unit or evaporator.
3. The method of claim 2 , wherein solvent separator is a wiped film evaporator.
4. The method of claim 3 , wherein the solvent comprises an aromatic solvent.
5. The method of claim 4 , wherein step (a) is performed at a temperature between about 50° C. to about 160° C.
6. The method of claim 1 , wherein at least about 80 wt. % of a total weight of asphalt originally in the asphalt-based roofing material is recovered as the asphalt product.
7. An asphalt product produced according to the method of claim 1 .
8. A system for producing at least an asphalt product from an asphalt-based roofing material containing a plurality of roofing shingles, the system comprising:
(a) an aggregate removal unit operable to remove substantially all aggregate from the asphalt-based roofing material to produce an aggregate-free asphalt/fiber mixture;
(b) a fiber separation unit operable to mix the aggregate-free asphalt/fiber mixture with a solvent to produce a slurry and to remove substantially all fiber from the slurry to produce an asphalt/solvent mixture; and
(c) a solvent separation unit operable to separate substantially all solvent from the asphalt to produce an asphalt product.
9. The system of claim 8 , wherein the aggregate removal unit comprises a separation tank configured to receive and combine the asphalt-based roofing material and at least one or more pressurized streams of a first fluid and to agitate or pulse a mixture of aggregate, a second fluid and the aggregate-free asphalt/fiber mixture.
10. The system of claim 9 , wherein the aggregate removal unit further comprises a dewatering or drying apparatus configured to remove moisture from the asphalt/fiber mixture.
11. The system of claim 8 , wherein the fiber separation unit comprises a mixing tank configured to receive and combine the aggregate-free asphalt/fiber mixture and a solvent and produce an asphalt/fiber/solvent slurry.
12. The system of claim 11 , wherein the fiber separation unit further comprises a fiber separator configured to receive the asphalt/fiber/solvent slurry and separate fiber from the asphalt/fiber/solvent slurry and produce an asphalt/solvent mixture and a fiber product.
13. The system of claim 8 , wherein the solvent separation unit comprises a solvent separator configured to receive the asphalt/solvent mixture and heat the mixture to separate the solvent from the mixture and produce the asphalt product.
14. The system of claim 13 , wherein the solvent separation unit further comprises a condenser configured to recover the solvent separated from the mixture.
15. The system of claim 8 , further comprising a pretreatment unit comprising a grinder operable to reduce the particle size of the asphalt-based roofing material and a feed system to deliver the asphalt-based roofing material to the aggregate removal unit.
16. The system of claim 8 , wherein the fiber separation unit is also operable to produce a substantially aggregate-free fiber product.