Pyrolysis method for the production of pyrolysis oil suitable for closed-loop recycling, related equipment, products and uses thereof

Abstract

The present invention relates to the treatment of plastic materials for use in chemical recycling processes to strengthen substantially plastic materials destined for waste. Specifically, the present invention relates to (a) providing a substantially plastic material to a pyrolysis reactor; (b) subjecting the material in the pyrolysis reactor to a temperature of between 330°C and 580°C in the substantial absence of oxygen and at a pressure between atmospheric and 13 bara; (c) maintaining the material in the pyrolysis reactor for a time sufficient to produce a gaseous effluent; (d) partially or completely condensing the gaseous effluent to form at least one fluid that is liquid at 25° C. and that contains at least 10% by weight of hydrocarbons, based on the weight of the substantially plastic material provided; (e) carrying out an evaluation of at least one property "Px" of the liquid condensed from said effluent in gaseous state by at least one measurement "Ax" of the spectrum of transmission, reflection or transflectance of the condensed liquid; (f) adjusting at least one process parameter "Ox" according to the evaluation of the at least one characteristic "Px", (g) iteratively repeating steps (e) and (f) to maintain at least one characteristic "Px" substantially constant over time. The present invention relates to a method for pyrolyzing a substantially plastic material to obtain hydrocarbons which are liquid at at least 25° C., comprising:

Claims

1. (a) providing a substantially plastic material to a pyrolysis reactor; (b) subjecting the material in the pyrolysis reactor to a temperature of between 330°C and 580°C in the substantial absence of oxygen, at a pressure between atmospheric and 13 bara; (c) maintaining the material in the pyrolysis reactor for a time sufficient to produce a gaseous effluent; (d) partially or completely condensing said effluent in gaseous state to form at least one fluid that is liquid at 25° C. and that contains at least 10% by weight of hydrocarbons, quantitatively relative to the weight of the substantially plastic material fed; (e) carrying out an evaluation of at least one property "Px" of the liquid condensed from said effluent in gaseous state by at least one measurement "Ax" of the spectrum of transmission, reflection or transflectance of said condensed liquid; (f) adjusting at least one process parameter "Ox" according to said evaluation of at least one property "Px", (g) iteratively repeating steps (e) and (f) to maintain said at least one characteristic "Px" substantially constant over time; Including, 13. A method for the pyrolysis of substantially plastic material to obtain hydrocarbons that are liquid at least at 25° C., wherein said measurement of "Ax" is performed directly on said condensed liquid by a spectrometer or spectrophotometer.

2. 2. A method for the pyrolysis of substantially plastic materials according to claim 1, wherein said at least one property "Px" of the liquid condensed by said effluent in gaseous state is refractive index and / or viscosity.

3. 3. A method for substantially pyrolyzing plastic materials according to claim 2, wherein said at least one property "Px" of the liquid condensed by said effluent in gaseous state is a refractive index.

4. 3. A method for substantially pyrolyzing plastic materials according to claim 2, wherein said at least one property "Px" of the liquid condensed by said effluent in gaseous state is viscosity.

5. 4. A method for substantially pyrolyzing plastic materials according to claim 3, wherein said adjustment of at least one process parameter "Ox" is performed by setting a set point of the refractive index characteristic "Px" to a value between 1.415 and 1.465nD, preferably between 1.42 and 1.455, more preferably between 1.425 and 1.

45.

6. 5. A method for substantially pyrolyzing plastic materials according to claim 4, wherein said adjustment of at least one process parameter "Ox" is performed by setting a set point of the viscosity characteristic "Px" to a value between 0.7 and 1.2 cP, preferably between 0.8 and 1.1 cP, more preferably between 0.85 and 1.05 cP.

7. 7. A method for pyrolyzing a substantially plastic material according to any one of claims 1 to 6, wherein the parameter "Ox" is at least one of the following: pyrolysis pressure, pyrolysis temperature, residence time of the substantially plastic material in the pyrolysis reactor, flow rate of the substantially plastic material in the pyrolysis reactor, and flow rate ratio between a plurality of substantially plastic materials fed to the pyrolysis reactor.

8. A method for the pyrolysis of substantially plastic materials according to any one of claims 1 to 7, wherein the waiting time between the measurement of the spectrum "Ax" and its use in adjusting the process parameter "Ox" can be set to a value not exceeding 1 hour, preferably not exceeding 10 minutes, more preferably to a value between 1 and 60 seconds.

9. 9. The method for the pyrolysis of substantially plastic materials according to any one of claims 1 to 8, wherein the step (d) of partially or totally condensing the effluent in gaseous state is obtained by partially condensing the effluent in gaseous state of the pyrolysis reactor by cooling at least a part of the effluent in gaseous state.

10. The method for substantially pyrolyzing plastic materials according to any one of claims 1 to 9, wherein the discharge in gaseous state in step (d) is pyrolysis steam contained directly in the pyrolysis reactor or is pyrolysis steam contained in an outlet duct of the pyrolysis steam from the pyrolysis reactor.

11. 11. The method for the pyrolysis of substantially plastic materials according to claim 10, wherein, when the effluent in gaseous state in step (d) is pyrolysis vapours contained in an outlet duct for pyrolysis vapours from the pyrolysis reactor, said vapours are conveyed to an area where at least partial condensation takes place, and said measurement "Ax" is carried out within 2 minutes, preferably between 1 and 60 seconds, after the vapours enter the outlet duct from the reactor.

12. Step (d) is withdrawing the pyrolysis vapor stream from the pyrolysis reactor through a pyrolysis vapor outlet duct; directing said withdrawn vapor stream to a condenser to condense at least 50% of the vapor; Carrying out a measurement "Ax" on the condensed liquid, preferably in the lower part of the condenser, which serves as a liquid storage volume; directing the non-condensable vapor to the pyrolysis reactor, to a pyrolysis vapor outlet duct, or to the remaining pyrolysis vapor prior to condensation in step (d) of the process; Sending the liquid to the pyrolysis reactor or to said pyrolysis vapor outlet duct, preferably by gravity, and returning the liquid to the main flow. A method for substantially pyrolyzing plastic material according to any one of claims 1 to 9, comprising:

13. A method for pyrolyzing a substantially plastic material according to any one of claims 1 to 12, comprising obtaining at least one calibration curve "Cx" capable of correlating the transmission, semi-transmission or reflection spectrum of the hydrocarbon liquid obtained by pyrolysis with the value of at least one property "Px" of said hydrocarbon liquid, said calibration curve "Cx" being obtained by applying a multivariate regression method, preferably Multiple Linear Regression (MLR), Principal Component Analysis (PCR) regression or Partial Least Squares (PLS) regression.

14. 14. A method for substantially pyrolyzing plastic material according to any one of the preceding claims, wherein the optical path of the light is less than 25 mm, or between 3 and 18 mm, or between 5 and 15 mm, or between 7 and 11 mm, when the measurement "Ax" is performed in transmission or semi-transmission mode.

15. The measurement "Ax" is at least 4000 to 12000 cm －１ , or 4500 to 10000 cm －１ , or 5000 to 9000 cm －１ 15. The method for substantially pyrolyzing plastic material according to any one of claims 1 to 14, which is carried out using a probe capable of emitting light having a wave number of 0.1 to 0.

5.

16. 16. A mixture obtainable from the process according to any one of claims 1 to 15, comprising at least 90% by weight of hydrocarbons, having a refractive index, measured according to the method defined below, of 1.415 to 1.465 nD, preferably 1.42 to 1.455, more preferably 1.425 to 1.45, and a viscosity, measured according to the method defined below, of 0.7 to 1.2 cP, preferably 0.8 to 1.1 cP, more preferably 0.85 to 1.05 cP, and a tetrahydrofuran (THF) content of less than or equal to 1% by weight, preferably 0.01% to 0.25% by weight, more preferably 0.07% to 0.19% by weight, relative to the total weight of the mixture.

17. 17. A mixture comprising at least 90% by weight of hydrocarbons according to claim 16, further comprising a C5 to C12 content at least equal to 35% by weight, a C21 and higher content at most equal to 3.5% by weight, up to 0.55% by weight, preferably between 0.15% and 0.3% by weight of isobutene, and / or up to 2% by weight, preferably between 0.01% and 1% by weight of benzoic acid, all percentages relative to the total weight of the mixture.

18. 18. Use of a mixture according to claim 16 or 17 in feeding a steam cracking plant to obtain monomers useful for the manufacture of polymers.

19. at least one reactor for substantially pyrolyzing plastic material, at least one condensation separator that receives and at least partially condenses vapor from the at least one reactor; At least one device for performing a measurement "Ax" of the spectrum of transmission, reflection or trans-transmission of a liquid condensed from said effluent in gaseous state, said measurement of "Ax" being performed directly on said condensed liquid using a spectrometer or spectrophotometer; at least one system for evaluating at least one property "Px" of the liquid condensed from said effluent in gaseous state by at least said measurements "Ax", at least one regulation system for a process parameter "Ox" as a function of said measurement value "Ax" of said at least one characteristic "Px"; 1. An apparatus for the pyrolysis of substantially plastic material to obtain hydrocarbons that are liquid at at least 25° C., comprising:

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