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EP-4441169-B1 - METHODS FOR REMOVAL OF SILICON AND CHLORIDE CONTAMINANTS FROM MIXED PLASTIC WASTE BASED PYROLYSIS OIL

EP4441169B1EP 4441169 B1EP4441169 B1EP 4441169B1EP-4441169-B1

Inventors

  • SHARMA, AMIT
  • CUOQ, FABRICE
  • LIU, Ziyu
  • BIBALAN, Safa Farajzadeh
  • RAO, SREENIVASA

Dates

Publication Date
20260513
Application Date
20221201

Claims (8)

  1. A method of treating a pyrolysis oil, the method comprising: supplying, to a reaction vessel, a pyrolysis oil containing a plurality of silicon compounds and a plurality of chloride compounds; mixing the pyrolysis oil with a first aqueous alkaline hydroxide solution in the reaction vessel operated at a temperature ranging from about 15 °C to about 30 °C, the first aqueous alkaline hydroxide solution having a pH of about 10 or greater; allowing the mixture of the pyrolysis oil and the first aqueous alkaline hydroxide solution to separate into a first upgraded pyrolysis oil fraction and a first aqueous fraction; removing the first aqueous fraction from the reaction vessel; mixing the first upgraded pyrolysis oil fraction and a second aqueous alkaline hydroxide solution in the reaction vessel operated at a temperature ranging from about 15 °C to 225 °C, the second aqueous alkaline hydroxide solution having a pH of about 10 or greater; allowing the mixture of the first upgraded pyrolysis oil fraction and the second aqueous alkaline hydroxide solution to separate into a second upgraded pyrolysis oil fraction and a second aqueous fraction; removing the second aqueous fraction from the reaction vessel; mixing the second upgraded pyrolysis oil fraction with a third aqueous alkaline hydroxide solution in the reaction vessel operated at a temperature ranging from about 15 °C to 30 °C, the third aqueous alkaline hydroxide solution having a pH of about 10 or greater; allowing the mixture of the second upgraded pyrolysis oil fraction and the third aqueous alkaline hydroxide solution to separate into a third upgraded pyrolysis oil fraction and a third aqueous fraction, the third upgraded pyrolysis oil fraction containing at least about 30 weight percent less of the plurality of silicon compounds than the plurality of silicon compounds in the pyrolysis oil and at least about 50 weight percent less of the plurality of chloride compounds than the plurality of chloride compounds in the pyrolysis oil; and extracting the third upgraded pyrolysis oil fraction and optionally supplying it to a hydroprocessing unit.
  2. The method of Claim 1, wherein the pyrolysis oil is a raw mixed plastic waste pyrolysis oil.
  3. The method of Claim 2, wherein the third upgraded pyrolysis oil fraction contains at least about 90 weight percent less of the plurality of chloride compounds than the plurality of chloride compounds in the raw mixed plastic waste pyrolysis oil.
  4. The method of Claim 1, wherein the pyrolysis oil is a light liquid fraction obtained from processing of raw mixed plastic waste pyrolysis oil at less than about 170 °C, defining a naphtha fraction.
  5. The method of Claim 4, wherein the third upgraded pyrolysis oil fraction contains at least about 80 weight percent less of the plurality of chloride compounds than the plurality of chloride compounds in the naphtha fraction.
  6. The method of Claim 1, wherein the pyrolysis oil is a medium liquid fraction obtained from processing of raw mixed plastic waste pyrolysis oil from about 170 °C to about 370 °C, defining a diesel fraction.
  7. The method of Claim 6, wherein the third upgraded pyrolysis oil fraction contains at least about 50 weight percent less of the plurality of chloride compounds than the plurality of chloride compounds in the diesel fraction.
  8. The method of Claim 1, wherein the method further comprises: supplying the third upgraded pyrolysis oil to the hydroprocessing unit

Description

Cross-Reference to Related Applications This application claims the benefit of and priority to U.S. Provisional Application No. 63/264,860, filed on December 3, 2021. Technical Field The present disclosure generally relates to systems and methods for processing mixed plastic waste pyrolysis oil to remove silicon and chloride contaminants. More specifically, the present disclosure relates to systems and methods for processing mixed plastic waste pyrolysis oil to produce a feedstock that is usable for a refinery unit, such as a hydrotreater, or a hydrocracker, or a combination thereof. Background Pyrolysis oil (pyoil) from the mixed plastic waste is emerging as an alternative feedstock via chemical recycling. Pyoil contains several contaminants such as silicon, chlorides, nitrogen, oxygenates and other heavy species. These contaminants result in several detrimental effects, such as fouling and downstream catalyst poisoning. Moreover, products derived from the processing of pyoil are subjected to strict elemental requirements to be used as a replacement for the fossil-based feedstock, such as naphtha or fuels. Presence of silicon and chloride contaminants limit further downstream applications. One way of processing the pyoil is to send it to a hydrotreater unit to remove the hetero-atom impurities, such as the silicon, oxygen compounds, nitrogen compounds, and chloride compounds along with saturating the unsaturated species. A drawback of this process is that the hydrotreater catalyst tends to coke rapidly due to heavy components. Another drawback is that such a process requires a large quantity of hydrogen and a large reactor due to the high level of contamination present in the raw pyoil. Moreover, the hydrotreatment of pyoils with such contaminants requires expensive and special metallurgical equipment to address the corrosion issues. WO 2021/105326 A1 discloses a method for upgrading liquefied waste plastics, the method comprising a step (A) of providing liquefied waste plastics (LWP) material, a step (B) comprising pre-treating the liquefied waste plastics material by contacting the liquefied waste plastics material with an aqueous medium having a pH of at least 7 at a temperature of 200°C or more. US 4,180,456 describes a method of processing a feed slurry containing fine solids, polar liquids and premium liquid oil and produced by high temperature hydrogenation of a solid fuel, such as coal. EP0187947 A1 describes a process for solvent refining of a residual oil. US2013/232857 A1 describes a method for mineralizing siloxane derivatives from a liquid organic phase by adding a base in the form of an alkaline hydroxide. Summary To address these shortcomings in the art, Applicant has developed methods for pretreating raw mixed plastic waste pyrolysis oil to remove silicon and chloride contaminants. Products formed from the hydrotreating of the pretreated mixed plastic waste pyrolysis oil can also be subject to further hydrocracking and distillation. The pyrolysis oil can be a raw mixed plastic waste pyrolysis oil or can be certain specific fractions. The pyrolysis oil obtained from processing of raw mixed plastic waste can be fractionated to provide multiple fractions, such as a light liquid fraction with a boiling point less than about 170 degrees centigrade (°C), a middle liquid fraction with a boiling point ranging from about 170 °C to about 370 °C, and a heavy end fraction with a boiling point greater than about 370 °C. In certain instances, this heavy end fraction has a boiling point greater than about 400 °C. A mixture of all the three fractions is called a full range pyrolysis oil. An embodiment of a method of treating a pyrolysis oil includes the step of supplying, to a reaction vessel, a pyrolysis oil containing a plurality of silicon compounds and a plurality of chloride compounds, mixing the pyrolysis oil with an aqueous alkaline hydroxide solution in the reaction vessel operated at a temperature ranging from about 15 °C to about 225 °C, allowing the mixture of the pyrolysis oil and the aqueous alkaline hydroxide solution to separate into an upgraded pyrolysis oil fraction and an aqueous fraction, extracting the upgraded pyrolysis oil fraction and optionally supplying it to a hydroprocessing unit. In certain embodiments, the pyrolysis oil is mixed with the aqueous alkaline hydroxide solution in the reaction vessel operated at a temperature ranging from about 15 °C to about 100 °C, or from about 15 °C to about 50 °C, or at room temperature. In certain embodiments, the alkaline hydroxide solution contains less than about 50 weight percent of the alkaline hydroxide. The aqueous alkaline hydroxide solution can contain less than about 20 weight percent of the alkaline hydroxide. The aqueous alkaline hydroxide solution can contain less than about 10 weight percent of the alkaline hydroxide. In certain embodiments, the alkaline hydroxide solution contains an amount of alkaline hydroxide ranging from abo