Method for catalytically cracking waste plastics and apparatus for catalytically cracking waste plastics

Abstract

To provide a method for catalytically cracking waste plastics wherein the efficiency in decomposition is high; even polyethylene composed of linear chain molecules difficult in decomposition is decomposable at a low temperature and decomposed residue is hardly produced; the process is simple since dechlorination can be achieved at the same time with catalytically cracking waste plastics in one reaction vessel; and oil fractions can be recovered at 50% or more on a net yield basis. The method for catalytically cracking waste plastics of the present invention has a constitution in which waste plastics are loaded as a raw material into a granular FCC catalyst heated to a temperature range from 350° C. to 500° C. inside a reaction vessel, thereby decomposing and gasifying the waste plastics in contact with the FCC catalyst.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view illustrating a method for catalytically cracking waste plastics and the apparatus therefore (reaction process) according to one example of the present invention.

FIG. 2 is a graph illustrating a relationship between the oil fraction efflux time and the cumulative run-off quantity (weight %) in a method for catalytically cracking waste plastics according to one example of the present invention.

FIG. 3 is a graph illustrating a carbon number distribution of products in a method for catalytically cracking waste plastics according to one example of the present invention.

FIG. 4 is a graph illustrating a relationship between the oil fraction efflux time and the cumulative run-off quantity (weight %) in a method for catalytically cracking waste plastics (the reaction temperature is changed at three different levels) according to another example of present invention.

FIG. 5 is a graph illustrating a carbon number distribution of products in a method for catalytically cracking waste plastics (the reaction temperature is changed at three different levels) according to another example of the present invention.

FIG. 6 is a graph illustrating a change in gas production in a method for catalytically cracking waste plastics (the reaction temperature is changed at three different levels) according to another example of the present invention.

FIG. 7 is a graph illustrating a relationship between the oil fraction efflux time and the cumulative run-off quantity (weight %) in a method for catalytically cracking waste plastics (FCC waste catalyst (FCC(U)) is used at three different quantity levels) according to another example of the present invention.

FIG. 8 is a graph illustrating a carbon number distribution of products in a method for catalytically cracking waste plastics (FCC waste catalyst (FCC(U)) is used at three different quantity levels) according to another example of the present invention.

FIG. 9 is a graph illustrating a change in gas production in a method for catalytically cracking waste plastics (FCC waste catalyst (FCC(U)) is used at three different quantity levels) according to another example of the present invention.

FIG. 10 is a graph illustrating a relationship between the oil fraction efflux time and the cumulative run-off quantity (weight %) in a method for catalytically cracking waste plastics (the raw material is changed to each of PE, PP and PS) according to another example of the present invention.

FIG. 11 is a graph illustrating a carbon number distribution of products in a method for catalytically cracking waste plastics (the raw material is changed to each of PE, PP and PS) according to another example of the present invention.

FIG. 12 is a graph illustrating a change in gas production in a method for catalytically cracking waste plastics (the raw material is changed to each of PE, PP and PS) according to another example of the present invention.

FIG. 13 is a graph illustrating a relationship between the oil fraction efflux time and the cumulative run-off quantity (weight %) inamethod for catalytically crackingwasteplastics (the raw material used is a mixture of PE, PP and PS) according to another example of the present invention.

FIG. 14 is a graph illustrating a carbon number distribution of products in a method for catalytically cracking waste plastics (the raw material used is a mixture of PE, PP and PS) according to another example of the present invention.

FIG. 15 is a graph illustrating a change in gas production in a method for catalytically cracking waste plastics (the raw material used is a mixture of PE, PP and PS) according to another example of the present invention.

FIG. 16 is a view illustrating yield of oil fraction of 90 minutes duration since waste plastics are loaded.

FIG. 17 is a graph illustrating a relationship between the oil fraction efflux time and the cumulative run-off quantity (weight %) in a method for catalytically cracking waste plastics (the raw material used is a mixture of PP with PVC) according to another example of the present invention.

FIG. 18 is a graph illustrating a carbon number distribution of products in a method for catalytically cracking waste plastics (the raw material used is a mixture of PP with PVC) according to another example of the present invention.

FIG. 19 is a graph illustrating a change in gas production in a method for catalytically cracking waste plastics (the raw material used is a mixture of PP with PVC) according to another example of the present invention.

FIG. 20 is a graph illustrating a relationship between the oil fraction efflux time the cumulative run-off quantity (weight %) in a method for catalytically cracking waste plastics (the raw material used is a mixture of PP with PVC and a Ca compound to be added is changed to each of CaO, CaCO₃ and Ca (OH)₂) according to another example of the present invention.

FIG. 21 is a graph illustrating a carbon number distribution of products in a method for catalytically cracking waste plastics (the raw material is a mixture of PP with PVC and a Ca compound to be added is changed to each of CaO, CaCO₃ and Ca(OH)₂) according to another example of the present invention.

FIG. 22 is a graph illustrating a change in gas production in a method for catalytically cracking waste plastics (the raw material is a mixture of PP with PVC and a Ca compound to be added is changed to each of CaO, CaCO₃ and Ca(OH)₂) according to another example of the present invention.

FIG. 23 is a graph illustrating the XRD analysis result of calcium hydroxide in a method for catalytically cracking waste plastics (the raw material is a mixture of PP with PVC and a Ca compound to be added is changed to each of CaO, CaCO₃ and Ca(OH)₂) according to another example of the present invention.

FIG. 24 is a graph illustrating a relationship between the oil fraction efflux time and the cumulative run-off quantity (weight %) in a method for catalytically cracking waste plastics (in the coexistence of the FCC waste catalyst (FCC(U)) with calcium hydroxide) according to another example of the present invention.

FIG. 25 is a graph illustrating a carbon number distribution of products in a method for catalytically cracking waste plastics (in the coexistence of the FCC waste catalyst (FCC(U)) with calcium hydroxide) according to another example of the present invention.

FIG. 26 is a graph illustrating a change in gas production in a method for catalytically cracking waste plastics (in the coexistence of the FCC waste catalyst (FCC(U)) with calcium hydroxide) according to another example of the present invention.

FIG. 27 is a graph illustrating the XRD analysis result of FCC(U)—Ca(OH)₂ in a method for catalytically cracking waste plastics (in the coexistence of the FCC waste catalyst (FCC (U)) with calcium hydroxide)according to another example of the present invention.

FIG. 28 is a graph illustrating the relationship between the oil fraction efflux time and the cumulative run-off quantity (weight %) in a method for catalytically cracking waste plastics (the material is a mixture of PP with PVC and a quantity of calcium hydroxide to be added is changed at three different levels) according to another example of the present invention.

FIG. 29 is a graph illustrating a carbon number distribution of products in a method for catalytically cracking waste plastics (the material is a mixture of PP with PVC and a quantity of calcium hydroxide to be added is changed at three different levels) according to another example of the present invention.

FIG. 30 is a graph illustrating a change in gas production in a method for catalytically cracking waste plastics (the material is a mixture of PP with PVC and a quantity of calcium hydroxide to be added is changed at three different levels) according to another example of the present invention.

FIG. 31 is a schematic view briefly illustrating the apparatus of reaction processes according to another example of the present invention.

FIG. 32 is a graph illustrating the material balance for the above case.

Claims

1. A method for catalytically cracking waste plastics wherein waste plastics are loaded as a raw material into a granular FCC catalyst heated to a temperature range from 350° C. to 500° C. inside a reaction vessel, thereby decomposing and gasifying the waste plastics in contact with the FCC catalyst.

2. A method for catalytically cracking waste plastics according to claim 1 wherein cracked gas generated through decomposition and gasification of the waste plastics is cooled to provide oil fractions.

3. A method for catalytically cracking waste plastics according to claim 1 wherein granular Ca compounds are mixed into a FCC catalyst.

4. A method for catalytically cracking waste plastics according to claim 2 wherein granular Ca compounds are mixed into a FCC catalyst.

5. A method for catalytically cracking waste plastics according to claim 3 wherein granular iron compounds are mixed into the FCC catalyst.

6. A method for catalytically cracking waste plastics according to claim 4 wherein granular iron compounds are mixed into the FCC catalyst.

7. A method for catalytically cracking waste plastics according to claim 5 wherein iron compounds contain iron hydroxide (III) (FeO(OH)).

8. A method for catalytically cracking waste plastics according to claim 6 wherein iron compounds contain iron hydroxide (III) (FeO(OH)).

9. A method for catalytically cracking waste plastics according to any one of claim 1 through claim 8 wherein the waste plastics are subjected to decomposition and gasification in an atmosphere where an inert gas is introduced inside a reaction vessel.

10. A method for catalytically cracking waste plastics according to any one of claim 1 through claim 8 wherein a reaction vessel is a rotary kiln-type reaction vessel and at least waste plastics is loaded continuously to effect decomposition and gasification.

11. A method for catalytically cracking waste plastics according to claim 9 wherein a reaction vessel is a rotary kiln-type reaction vessel and at least waste plastics is loaded continuously to effect decomposition and gasification.

12. A method for catalytically cracking waste plastics according to any one of claim 1 through claim 8 wherein FCC catalysts is waste catalysts.

13. A method for catalytically cracking waste plastics according to claim 9 wherein FCC catalysts is waste catalysts.

14. A method for catalytically cracking waste plastics according to claim 10 wherein FCC catalysts is waste catalysts.

15. A method for catalytically cracking waste plastics according to claim 11 wherein FCC catalysts is waste catalysts.

16. An apparatus for catalytically cracking waste plastics which is provided with a reaction vessel having a heating means for heating a granular FCC catalyst to a temperature range from 350° C. to 500° C. and an agitating means for mixing and agitating the FCC catalyst with waste plastics as a raw material.

17. An apparatus for catalytically cracking waste plastics according to claim 16 which is provided with a cooling mechanism for cooling and liquefying cracked gas generated through decomposition of waste plastics.

18. An apparatus for catalytically cracking waste plastics according to claim 17 or claim 18 wherein a reaction vessel is a rotary kiln-type reaction vessel.