Recycling and reduction of plastics and non-plastics material

• US 7,799,835 B2
• Filed: 03/04/2004
• Issued: 09/21/2010
• Est. Priority Date: 03/13/2003
• Status: Expired due to Fees

• Current Assignee: Next-Tec, Ltd.
• Original Assignee: Next-Tec, Ltd.
• Inventors: Smith, Philip Mark, Smith, Peter Anthony, Koffler, Adam J.
• Primary Examiner(s): Choi; Ling-Siu
• Assistant Examiner(s): Tischler; Frances
• Application Number:
  US10/793,184
• Publication Number:
  US 20040235970A1
• Time in Patent Office: 2,392 Days
• Field of Search: 521/45.5, 521/46.5, 521/40, 521/40.5, 521/41, 521/42, 521/42.5, 521/46, 521/48, 521/48.5, 264/918, 264/913, 264/37.1, 219/60, 250/316.1, 250/330, 250/338.1, 250/338.5, 250/339.01, 250/339.09, 250/339.11, 250/339.12, 250/340, 250/341.1, 250/341.5, 528/480, 528/481, 528/502.R, 528/502.F, 528/503, 209/552, 209/576, 209/577
• US Class Current: 521/40
• CPC Class Codes: B29B 17/02 Separating plastics from other materials
• CPC Class Codes: B29B 2017/0203 Separating plastics from plastics
• CPC Class Codes: B29B 2017/0279 Optical identification, e.g. cameras or spectroscopy
• CPC Class Codes: B29K 2023/06 PE, i.e. polyethylene
• CPC Class Codes: B29K 2023/0633 LDPE, i.e. low density polyethylene
• CPC Class Codes: B29K 2023/065 HDPE, i.e. high density polyethylene
• CPC Class Codes: B29K 2023/083 EVA, i.e. ethylene vinyl acetate copolymer
• CPC Class Codes: B29K 2023/12 PP, i.e. polypropylene
• CPC Class Codes: B29K 2025/00 Use of polymers of vinyl-aromatic compounds or derivatives thereof as moulding material
• CPC Class Codes: B29K 2027/06 PVC, i.e. polyvinylchloride
• CPC Class Codes: B29K 2033/18 Polymers of nitriles
• CPC Class Codes: B29K 2067/00 Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2077/00 Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2105/0026 Flame proofing or flame retarding agents
• CPC Class Codes: B29K 2705/00 Use of metals, their alloys or their compounds, for preformed parts, e.g. for inserts
• CPC Class Codes: B29L 2031/753 Medical equipment; Accessories therefor bloodbags, medical bags B29L2031/7148; artificial eyes B29L2011/0008
• CPC Class Codes: B29L 2031/7544 Injection needles, syringes
• CPC Class Codes: C08J 11/06 without chemical reactions
• CPC Class Codes: Y02W 30/62 Plastics recycling; Rubber recycling

Abstract

The present invention provides, e.g., methods to recycle and/or reduce plastic, non-plastic, or a combination thereof, from a waste stream. The methods of the present invention include contacting the plastic waste with infrared (IR) energy at one or more frequencies and at one or more intensities, over a period of time effective to heat plastic present in the plastic waste.

Claims

1. A method comprising:

(a) separating a waste stream that includes plastic waste, such that at least a portion of non-plastic waste, unplasticized polyvinyl chloride (UPVC), plastics treated with a fire retardant, or a combination thereof is separated from the waste stream, thereby providing a plastic waste;

(b) reducing the size of the plastic waste;

(c) analyzing the plastic waste, in which analyzing includes;

projecting an infrared light through the plastic waste to one or more detectors sufficient to provide a spectral content, the infrared light having at least two distinct frequency components;

analyzing the spectral content of the infrared light transmitted through the plastic waste; and

comparing the spectral content of the infrared light transmitted through the plastic waste to known spectral content profiles for two or more materials to determine which of the two or more materials comprise the plastic waste;

(d) removing solid particles, organic matter, contaminants, metal contaminants, or a combination thereof, from the plastic waste;

(e) calibrating an infrared (IR) source to the plastic waste, wherein the calibrating occurs after analyzing;

(f) contacting the plastic waste with infrared (IR) energy at one or more frequencies and at one or more intensities, over a period of time effective to heat plastic present in the plastic waste;

(g) contacting the plastic waste with infrared (IR) energy at one or more frequencies and at one or more intensities, over a period of time effective to alter the volume of the plastic waste;

(h) contacting the plastic waste with infrared (IR) energy at one or more frequencies and at one or more intensities, over a period of time effective to reduce the weight of the plastic waste; and

(i) cooling the heated plastic waste;

thereby effectively providing recycled plastic, reduced plastic, or a combination thereof.

2. The method of claim 1 wherein the waste stream that includes plastic waste comprises at least about 70 wt. % plastic.

3. The method of claim 1 wherein the waste stream that includes plastic waste comprises at least about 80 wt. % plastic.

4. The method of claim 1 wherein the waste stream that includes plastic waste comprises at least about 90 wt. % plastic.

5. The method of claim 1 wherein the plastic waste comprises a thermoset plastic.

6. The method of claim 1 wherein the plastic waste comprises a thermoplastic plastic.

7. The method of claim 1 wherein the plastic waste comprises a plastic selected from the group of polyethylene terephthalate, high density polyethylene, poly vinyl chloride, low density polyethylene, polypropylene, polystyrene, or any combination thereof.

8. The method of claim 1 wherein the analyzing comprises:

projecting an infrared light having at least two distinct spectral frequency components through free space to an infrared light detector;

determining the spectral intensity of light received at the infrared light detector through free space;

projecting the infrared light having at least two distinct spectral frequency components through the plastic waste;

determining the spectral intensity of light received at the infrared light detector through the plastic waste; and

deriving spectral absorption data for the waste material by comparing the spectral intensity of light received through free space to the spectral intensity of light received through the plastic waste.

9. The method of claim 1 wherein the reducing of the size of the plastic waste employed comprises at least one of shredding, cutting, slicing, ripping, shaving, tearing, slashing, carving, cleaving, cutting, dissevering, hacking, incising, severing, shearing, fragmenting, fraying, lacerating, and grinding, of the plastic waste.

10. The method of claim 1 wherein the calibrating comprises estimating a composition of the plastic waste and a weight of the plastic waste, and deriving an infrared exposure from the composition and weight.

11. The method of claim 10, wherein derived infrared exposure comprises determining at least one of time of exposure and intensity of infrared light.

12. The method of claim 1 wherein the infrared energy in step (f), (g), (h), or a combination thereof, is of a frequency between about 600 cm⁻

1 and about 6000 cm<sup>−

1</sup>.

13. The method of claim 1 wherein the intensity in step (f), (g), (h), or a combination thereof, is selected to heat waste material having a specific heat of about 0.2 to about 0.6 BTU/lb/degree Farenheit to a desired temperature.

14. The method of claim 1 wherein the period of time in step (f), (g), (h), or a combination thereof, is selected based on the intensity of the infrared source, the desired increase in temperature, and the plastic waste specific heat of about 0.2 to about 0.6 BTU/lb/degree Farenheit.

15. The method of claim 1 wherein step (f), (g), (h), or a combination thereof, is carried out at a pressure above about 1 atm.

16. The method of claim 1 wherein step (f), (g), (h), or a combination thereof, is carried out at a pressure above about 2 atm.

17. The method of claim 1 wherein step (f), (g), (h), or a combination thereof, is carried out at the one or more frequencies, at the one or more intensities, and over the period of time, effective to melt plastic present in the plastic waste.

18. The method of claim 1 wherein step (f), (g), (h), or a combination thereof, is carried out for a period of time effective to remove moisture present in the plastic waste.

19. The method of claim 1 wherein step (f), (g), (h), or a combination thereof, is carried out for a period of time effective to sterilize the plastic waste.

20. The method of claim 1 wherein step (f), (g), (h), or a combination thereof, is carried out for a period of time effective to render the plastic waste chemically inert.

21. The method of claim 1 wherein the infrared (IR) energy in any or all of the steps is applied in a pulsating manner.

22. The method of claim 1 wherein the infrared (IR) energy in any or all of the steps is applied in a continuous manner.

23. The method of claim 1 wherein the infrared (IR) energy in any or all of the steps is applied directly to the plastic waste.

24. The method of claim 1 wherein the infrared (IR) energy in any or all of the steps is applied indirectly to the plastic waste.

25. The method of claim 1 wherein the plastic has a melting point of about 150°

C. to about 280°

C.

26. The method of claim 1 wherein the plastic has a melting point of about 170°

C. to about 260°

C.

27. The method of claim 1 wherein the plastic has a combustion point of about 200°

C. to about 325°

C.

28. The method of claim 1 wherein the plastic has a combustion point of about 220°

C. to about 300°

C.

29. The method of claim 1 wherein more than about 50 kilograms of waste stream per hour are recycled.

30. The method of claim 1 wherein up to about 15 million kilograms of waste stream per year are recycled.

31. The method of claim 1 wherein the plastic waste comprises one type of plastic, having a melting point and a combustion point.

32. The method of claim 1 wherein the plastic waste comprises multiple types of plastic, each independently having a melting point and a combustion point.

33. The method of claim 1 wherein the plastic waste comprises multiple types of plastic, each independently having a melting point and a combustion point that is substantially the same as the melting point and combustion point of another type of plastic present therein.

34. The method of claim 1 wherein the plastic waste comprises multiple types of plastic, each independently having a melting point and a combustion point that are substantially different from the melting point and combustion point of the other types of plastic present therein.

35. The method of claim 1 wherein the recycled plastic, the reduced plastic, or the combination thereof comprises sterile plastic.

36. The method of claim 1 wherein the recycled plastic, the reduced plastic, or the combination thereof comprises inert plastic.

37. The method of claim 1 wherein the recycled plastic, the reduced plastic, or the combination thereof is a flake or flakes of plastic.

38. The method of claim 1 wherein the recycled plastic, the reduced plastic, or the combination thereof is a briquette or briquettes of plastic.

39. The method of claim 1 wherein more than about 50 kilograms per hour of the recycled plastic, the reduced plastic, or the combination thereof are obtained.

40. The method of claim 1 wherein more than about 500 kilograms per hour of the recycled plastic, the reduced plastic, or the combination thereof are obtained.

41. The method of claim 1 wherein the recycled plastic, the reduced plastic, or the combination thereof comprises plastic in more than about 70 wt. %.

42. The method of claim 1 wherein the recycled plastic, the reduced plastic, or the combination thereof comprises plastic in more than about 80 wt. %.

43. The method of claim 1 wherein the recycled plastic, the reduced plastic, or the combination thereof comprises plastic in more than about 90 wt. %.

44. The method of claim 1 wherein the recycled plastic, the reduced plastic, or the combination thereof further comprises a contaminant selected from the group of household contaminants, agricultural contaminants, and industrial contaminants.

45. The method of claim 1 wherein the recycled plastic, the reduced plastic, or the combination thereof further comprises a contaminant selected from the group of food residue, drink residue, paper, animal soiling, human soiling, blood tissue, effluence, waste vegetable contamination, cleaning fluids, household chemicals, silage, grass, general vegetation residue, animal slurry, fertilizer, chemicals, crossed link polymers, and lubricants.

46. The method of claim 1 further comprising casting the heated plastic in a mold or cast.

47. The method of claim 1 wherein the reducing of the volume of the plastic waste comprises reducing the volume of the plastic waste by up to about 90%.

48. The method of claim 1 wherein the reducing of the volume of the plastic waste comprises removing up to about 90% of moisture present in the plastic waste.

49. The method of claim 1 wherein the weight ratio of the plastic waste to the recycled plastic, the reduced plastic, or the combination thereof is less than about 50%.

50. The method of claim 1 wherein the weight ratio of the plastic waste to the recycled plastic, the reduced plastic, or the combination thereof is less than about 10%.

51. The method of claim 1 wherein the weight ratio of the plastic waste to the recycled plastic, the reduced plastic, or the combination thereof is less than about 5%.

52. The method of claim 1 wherein steps (a) through (i) are carried out in the order recited therein.

53. A recycled plastic prepared by the process of claim 1.

54. A recycled non-plastic prepared by the process of claim 1.

55. The recycled waste material of claim 53 or 54 useful for at least one of a building material, a fuel additive, a fuel having a calorifinic value of at least 40 mJ/kg, a fuel accelerant, clothing fiber, a tote bag, furniture, a carpet, a new beverage container, a detergent bottle, an oil bottle, a vitamin bottle, a drain pipe, a recycling bin, a dog house, plastic lumber, packaging material, a binder, a mat, a deck, paneling, a roadway gutter, a mud flap, a speed bump, an envelope, a trash can, a trash liner, furniture, flooring tile, a compost bin, lumber, a signal light, a car battery component, a broom, a brush, an oil funnel, an ice scraper, a bike rack, a pallet, a storage bin, a tray, a thermometer, a switch plate, insulation, foam packaging, an egg carton, and a vent.

56. A method comprising:

(a) separating a waste stream that includes plastic waste, such that at least a portion of non-plastic waste, unplasticized polyvinyl chloride (UPVC), plastics treated with a fire retardant, or a combination thereof is separated from the waste stream, thereby providing a plastic waste;

(b) analyzing the plastic waste, in which analyzing includes;

projecting an infrared light through the plastic waste to one or more detectors sufficient to provide a spectral content, the infrared light having at least two distinct frequency components;

analyzing the spectral content of the infrared light transmitted through the plastic waste; and

comparing the spectral content of the infrared light transmitted

through the plastic waste to known spectral content profiles for two or more materials to determine which of the two or more materials comprise the plastic waste;

(c) contacting the plastic waste with infrared (IR) energy at one or more frequencies and at one or more intensities, over a period of time effective to heat plastic present in the plastic waste; and

(d) contacting the plastic waste with infrared (IR) energy at one or more frequencies and at one or more intensities, over a period of time effective to reduce the weight of the plastic waste;

thereby effectively providing recycled plastic, reduced plastic, or a combination thereof.

57. The method of claim 56, further comprising reducing the size of the plastic waste.

58. The method of claim 56, further comprising contacting the plastic waste with infrared (IR) energy at one or more frequencies and at one or more intensities, over a period of time effective to alter the volume of the plastic waste.

59. The method of claim 56, further comprising removing solid particles, organic matter, contaminants, metal contaminants, or a combination thereof, from the plastic waste.

60. The method of claim 56, further comprising cooling the heated plastic waste.

61. The method of claim 56, further comprising calibrating an infrared (IR) source to the plastic waste.

62. A method comprising:

(a) separating a waste stream that includes plastic waste, such that at least a portion of non-plastic waste, unplasticized polyvinyl chloride (UPVC), plastics treated with a fire retardant, or a combination thereof is separated from the waste stream, thereby providing a plastic waste;

(b) analyzing the plastic waste, in which analyzing includes;

projecting an infrared light having at least two distinct spectral frequency components through free space to an infrared light detector;

determining the spectral intensity of light received at the infrared light detector through free space;

projecting the infrared light having at least two distinct spectral frequency components through the plastic waste to one or more detectors;

determining the spectral intensity of light received at the infrared light detector through the plastic waste; and

deriving spectral absorption data for the waste material by comparing the spectral intensity of light received through free space to the spectral intensity of light received through the plastic waste;

(c) contacting the plastic waste with infrared (IR) energy at one or more frequencies and at one or more intensities, over a period of time effective to heat plastic present in the plastic waste; and

(d) contacting the plastic waste with infrared (IR) energy at one or more frequencies and at one or more intensities, over a period of time effective to reduce the weight of the plastic waste;

thereby effectively providing recycled plastic, reduced plastic, or a combination thereof.

63. The method of claim 62, further comprising reducing the size of the plastic waste.

64. The method of claim 62, further comprising contacting the plastic waste with infrared (IR) energy at one or more frequencies and at one or more intensities, over a period of time effective to alter the volume of the plastic waste.

65. The method of claim 62, further comprising removing solid particles, organic matter, contaminants, metal contaminants, or a combination thereof, from the plastic waste.

66. The method of claim 62, further comprising cooling the heated plastic waste.

67. The method of claim 62, further comprising calibrating an infrared (IR) source to the plastic waste.

68. A method comprising:

(a) separating a waste stream that includes plastic waste, such that at least a portion of non-plastic waste, unplasticized polyvinyl chloride (UPVC), plastics treated with a fire retardant, or a combination thereof is separated from the waste stream, thereby providing a plastic waste;

(b) analyzing the plastic waste, in which analyzing includes;

projecting an infrared light through the plastic waste to one or more detectors sufficient to provide a spectral content, the infrared light having at least two distinct frequency components;

analyzing the spectral content of the infrared light transmitted through the plastic waste; and

comparing the spectral content of the infrared light transmitted through the plastic waste to known spectral content profiles for two or more materials to determine which of the two or more materials comprise the plastic waste;

(c) calibrating an infrared (IR) source to the plastic waste, in which the calibrating includes;

estimating a composition of the plastic waste and a weight of the plastic waste, and deriving an infrared exposure from the composition and weight;

(d) contacting the plastic waste with infrared (IR) energy at one or more frequencies and at one or more intensities, over a period of time effective to heat plastic present in the plastic waste;

thereby effectively providing recycled plastic, reduced plastic, or a combination thereof.

69. The method of claim 68, further comprising contacting the plastic waste with infrared (IR) energy at one or more frequencies and at one or more intensities, over a period of time effective to alter the volume of the plastic waste.

70. The method of claim 68, further comprising reducing the size of the plastic waste.

71. The method of claim 68, further comprising cooling the heated plastic waste.

72. The method of claim 68, further comprising removing solid particles, organic matter, contaminants, metal contaminants, or a combination thereof, from the plastic waste.

73. The method of claim 68, wherein derived infrared exposure comprises determining at least one of time of exposure and intensity of infrared light.

74. The method of claim 68, further comprising contacting the plastic waste with infrared (IR) energy at one or more frequencies and at one or more intensities, over a period of time effective to reduce the weight of the plastic waste.