Dechlorination of liquid and gaseous flows from plastic pyrolysis processes

Abstract

Methods and materials for dechlorinating liquid and gas streams are described. In at least one embodiment, the method comprises contacting a plastic pyrolysis stream with an alumina adsorbent, the alumina adsorbent comprising an accelerator (e.g., sodium). In another embodiment, the method comprises contacting a plastic pyrolysis stream with an adsorbent comprising copper oxide, zinc oxide, and alumina.

Description

[Technical Field]

[0001] References to related applications This application claims priority to U.S. Provisional Patent Application No. 63 / 455,733, filed on March 30, 2023, the disclosures of which are incorporated herein by reference in their entirety. [Background technology]

[0002] Recycling of mixed waste plastics using chemical / monomer recycling is a critically important area. While several chemical recycling methods are being considered, pyrolysis remains the most technically feasible method for integrating steam crackers into the value chain. Commercialized plastic pyrolysis processes generally prefer to use polyolefins as raw material plastics. However, pure polyolefin waste is rarely available in quantities relevant to a full industrial scale, and / or requires expensive pre-sorting to remove other types of plastics (i.e., polystyrene, polyamide, polyethylene terephthalate, polyvinyl chloride, etc.). In small to medium-sized pyrolysis plants, it has been shown that it is currently impossible to completely remove halogen, nitrogen, and oxygen-containing polymers from raw material plastics.

[0003] Most plastic pyrolysis plants produce a liquid containing the following components on average: 50–400 ppmw of chloride, 1000–4000 ppmw of nitrogen, 2000–20000 ppmw of oxygen, and 100–1000 ppmw of sulfur. These levels are too high to be used as a raw material for steam crackers without mixing with conventional naphtha. Upgrading the pyrolysis liquid to remove impurities is crucial to meet the specifications for naphtha for steam crackers.

[0004] Hydrogenation is the only commercially available solution on a large scale that can reduce these impurities to the 1-5 ppmw level, making these liquids suitable as drop-in alternatives to naphtha crackers. Hydrogenation is standardized in the refining process and requires no major process adjustments when applied to plastic pyrolysis liquids. The only major exception is chloride / halogen compounds. Hydrogenation catalysts hydrogenate -N, -O, -S, and -Cl compounds, producing NH3, H2O, H2S, and HCl, respectively. However, high chloride content in such units (i.e., over 10 ppmw) leads to the following problems: (1) the reaction of NH3 with HCl produces NH4Cl, which deposits at temperatures below 100°C and clogs the equipment; (2) catalyst deactivation; and (3) the need for expensive steel. Therefore, alternative and / or improved materials and processes are needed. [Overview of the project]

[0005] This specification discloses and describes adsorbents, methods for producing them, and methods for using them in dechlorination processes.

[0006] One aspect of the present disclosure relates to a method for removing chloride from a plastic pyrolysis stream with an initial chloride concentration exceeding approximately 10 ppmw. In at least one embodiment, the method comprises contacting the stream with an alumina adsorbent, the alumina adsorbent comprising a sodium-containing accelerator. In at least one embodiment, the final chloride concentration of the treated stream is less than approximately 10 ppmw.

[0007] In at least one embodiment, the initial chloride concentration is approximately 10 ppmw to approximately 45 ppmw. In at least one embodiment, the initial chloride concentration is approximately 45 ppmw to approximately 250 ppmw.

[0008] In at least one embodiment, the accelerator is present in an amount of about 2% to about 10% by mass, based on the total mass of the adsorbent. In at least one embodiment, the accelerator comprises sodium in the form of Na2O.

[0009] In at least one embodiment, the alumina adsorbent has a BET specific surface area of about 150 m 2 / g to about 300 m 2 / g.

[0010] In at least one embodiment, the alumina adsorbent has a total pore volume of about 0.2 mL / g to about 6 mL / g.

[0011] In at least one embodiment, the alumina adsorbent exhibits a bimodal pore size distribution.

[0012] In at least one embodiment, the alumina adsorbent has a density of about 0.5 g / ml to about 1.0 g / ml.

[0013] In at least one embodiment, the alumina adsorbent is in the form of spherical particles. In at least one embodiment, the spherical particles have an average diameter of about 2 mm to about 4 mm. In at least one embodiment, the particles exhibit a lateral compression strength exceeding about 40 N.

[0014] In at least one embodiment, when the temperature of the pyrolysis stream is 200°C to 350°C, the chloride removal rate is at least about 80%, at least about 85%, or at least about 90%.

[0015] In at least one embodiment, the alumina adsorbent is regenerable.

[0016] In at least one embodiment, the method further includes contacting the alumina adsorbent with a regeneration stream to regenerate the alumina adsorbent. In at least one embodiment, the regeneration stream includes hydrogen gas at a temperature of about 450°C to about 600°C.

[0017] In at least one embodiment, the regeneration stream includes oxygen gas at a temperature of about 250°C to about 350°C.

[0018] A further aspect of the present disclosure relates to a method for removing chlorides from a plastic pyrolysis stream having an initial chloride concentration exceeding about 10 ppmw. In at least one embodiment, the method includes contacting the stream with an adsorbent. The adsorbent includes copper oxide, zinc oxide, and alumina. In at least one embodiment, the final chloride concentration of the treated stream is less than about 10 ppmw.

[0019] In at least one embodiment, the initial chloride concentration is from about 10 ppmw to about 45 ppmw. In at least one embodiment, the initial chloride concentration is from about 45 ppmw to about 250 ppmw.

[0020] In at least one embodiment, the copper oxide is present at about 50 wt% to about 80 wt% based on the total mass of the adsorbent.

[0021] In at least one embodiment, the zinc oxide is present at about 20 wt% to about 30 wt% based on the total mass of the adsorbent.

[0022] In at least one embodiment, the alumina is present at about 3 wt% to about 10 wt% based on the total mass of the adsorbent.

[0023] In at least one embodiment, the copper oxide is present at about 50 wt% to about 80 wt%, the zinc oxide is present at about 10 wt% to about 40 wt%, and the alumina is present as the remaining portion of the mass of the adsorbent.

[0024] In at least one embodiment, the adsorbent is formed by coprecipitation of copper oxide and zinc oxide on alumina.

[0025] In at least one embodiment, the adsorbent has a BET specific surface area of about 25 m 2 / g to about 150 m 2 / g.

[0026] In at least one embodiment, the adsorbent has a total pore volume of about 0.15 ml / g to about 2 ml / g.

[0027] In at least one embodiment, the density of the adsorbent is approximately 1.0 g / mL to approximately 3.0 g / mL.

[0028] In at least one embodiment, the adsorbent is in the form of a tablet. In at least one embodiment, the tablet has an average length of about 3 mm to about 6 mm and an average width of about 2 mm to about 4 mm.

[0029] In at least one embodiment, the tablet exhibits a lateral compressive strength exceeding approximately 60 N.

[0030] In at least one embodiment, when the temperature of the pyrolysis stream is 200°C to 350°C, the chloride removal rate is at least about 80%, at least about 85%, or at least about 90%.

[0031] In at least one embodiment, the adsorbent is regenerative.

[0032] In at least one embodiment, the method further includes regenerating the adsorbent by bringing it into contact with a regeneration stream. In at least one embodiment, the regeneration stream contains hydrogen gas at a temperature of about 450°C to about 600°C. In at least one embodiment, the regeneration stream contains oxygen gas at a temperature of about 250°C to about 350°C. [Brief explanation of the drawing]

[0033] The disclosures described herein are illustrated by the accompanying drawings and are not limited thereto. [Figure 1] Figure 1 is a plot showing the pore volume distribution of a sample prepared according to the examples described herein compared to a control sample. [Figure 2]Figure 2 is a plot showing the relationship between chloride removal rate and temperature for samples prepared according to the embodiments described herein and for a control sample. [Figure 3] Figure 3 is a plot showing the relationship between chloride removal rate and temperature for samples prepared according to the embodiments described herein and two reference samples. [Modes for carrying out the invention]

[0034] Embodiments of this disclosure relate to methods and compositions for efficiently removing chlorides from plastic pyrolysis streams (which may be liquid or gaseous streams). For example, certain embodiments utilize adsorbents containing an accelerator (e.g., sodium) for removing chlorides from plastic pyrolysis streams (e.g., those with an initial chloride concentration greater than about 10 ppmw). Formulations containing sodium on a highly porous volume carrier (e.g., highly porous volume alumina enhanced with copper or sodium) have been found to be effective in removing chlorides (e.g., to levels less than 10 ppmw or sub-ppmw). Other embodiments relate to adsorbents containing precipitated copper oxide (e.g., which can be co-precipitated with zinc oxide) on a carrier.

[0035] The adsorbent described may utilize a porous carrier and one or more active metal components supported thereon. Examples of carriers include metal oxides, metalloid oxides, activated carbon, and molecular sieves. For example, the carrier may include titanium oxide, ceria, alumina, silica, zirconia, magnesium oxide, zeolite, or a combination thereof. In at least one embodiment, the carrier includes silica. In at least one embodiment, the carrier may include a metal oxide with a high specific surface area. In at least one embodiment, the carrier may include aluminum oxide. In at least one embodiment, the carrier may include a mixture of titanium dioxide and aluminum oxide. A metal oxide mixture, such as a mixture of titanium dioxide and aluminum oxide, may contain metal oxides in a mass ratio of titanium dioxide to aluminum oxide ranging from approximately 9 / 1, approximately 8 / 1, approximately 7 / 1, approximately 6 / 1, approximately 5 / 1, approximately 4 / 1, approximately 3 / 1, approximately 2 / 1, or approximately 1 / 1, to approximately 1 / 2, approximately 1 / 3, approximately 1 / 4, approximately 1 / 5, approximately 1 / 6, approximately 1 / 7, approximately 1 / 8, or approximately 1 / 9.

[0036] In at least one embodiment, the adsorbent comprises a highly porous carrier such as highly porous alumina. In at least one embodiment, the accelerator is dispersed on the carrier, for example, by impregnation. The term “dispersion form” may be synonymous with “dispersed on it,” “impregnated in it,” “supported,” etc.

[0037] In at least one embodiment, an accelerator material or its precursor is combined with a carrier to facilitate initial wetting and impregnation, and the impregnated carrier is subsequently dried and calcined.

[0038] The adsorbents described herein can be prepared in a variety of ways. For example, a metal can be dispersed in a carrier by an initial wetting technique. Generally, "impregnation" means that the material is "inside" the pores of the carrier. In at least one embodiment, the metal is precipitated on the carrier. In at least one embodiment, the metal can be reduced after being dispersed or precipitated on the carrier.

[0039] In at least one embodiment, the adsorbent includes an accelerator (e.g., Na2O) which may be present in an amount from about 0.5% by mass to about 20% by mass based on the total mass of the adsorbent. In at least one embodiment, the accelerator (e.g., NaO) may be present in an amount from about 0.5% by mass, about 1% by mass, about 2% by mass, about 3% by mass, about 4% by mass, about 5% by mass, about 6% by mass, about 7% by mass, about 8% by mass, about 9% by mass, about 10% by mass, about 11% by mass, about 12% by mass, about 13% by mass, about 14% by mass, about 15% by mass, about 16% by mass, about 17% by mass, about 18% by mass, about 19% by mass, about 20% by mass, or any range including these points (e.g., from about 2% by mass to about 10% by mass), based on the total mass of the adsorbent.

[0040] In at least one embodiment, the adsorbent includes copper oxide (e.g., precipitated copper oxide) which may be present in about 50% to about 80% by mass based on the total mass of the adsorbent. In at least one embodiment, copper oxide can be present in about 50% by mass, about 51% by mass, about 52% by mass, about 53% by mass, about 54% by mass, about 55% by mass, about 56% by mass, about 57% by mass, about 58% by mass, about 59% by mass, about 60% by mass, about 61% by mass, about 62% by mass, about 63% by mass, about 64% by mass, about 65% by mass, about 66% by mass, about 67% by mass, about 68% by mass, about 69% by mass, about 70% by mass, about 71% by mass, about 72% by mass, about 73% by mass, about 74% by mass, about 75% by mass, about 76% by mass, about 77% by mass, about 78% by mass, about 79% by mass, about 80% by mass, or any range including these points (e.g., from about 65% by mass to about 75% by mass).

[0041] In at least one embodiment, the adsorbent comprises zinc oxide (e.g., precipitated zinc oxide) that may be present in the range of about 10 wt% to about 40 wt% based on the total mass of the adsorbent. In at least one embodiment, the zinc oxide can be present at about 10 wt%, about 11 wt%, about 12 wt%, about 13 wt%, about 14 wt%, about 15 wt%, about 16 wt%, about 17 wt%, about 18 wt%, about 19 wt%, about 20 wt%, about 21 wt%, about 22 wt%, about 23 wt%, about 24 wt%, about 25 wt%, about 26 wt%, about 27 wt%, about 28 wt%, about 29 wt%, about 30 wt%, about 31 wt%, about 32 wt%, about 33 wt%, about 34 wt%, about 35 wt%, about 36 wt%, about 37 wt%, about 38 wt%, about 39 wt%, about 40 wt%, or any range defined by and including these points (e.g., about 15 wt% to about 35 wt%).

[0042] The surface area discussed herein is determined by the Brunauer - Emmett - Teller (BET) method in accordance with DIN ISO 9277:2003 - 05 (revision of DIN 66131), which is also referred to as the "BET surface area". The specific surface area is determined by multi - point BET measurements in the relative pressure range of 0.05 - 0.3 p / p0. In at least one embodiment, the adsorbent has a surface area of about 100 m 2 / g, about 110 m 2 / g, about 120 m 2 / g, about 130 m 2 / g, about 140 m 2 / g, about 150 m 2 / g, about 160 m 2 / g, about 170 m 2 / g, about 180 m 2 / g, about 190 m 2 / g, about 200 m 2 / g, about 210 m 2 / g, about 220 m 2 / g, about 230 m 2 / g, about 240 m 2 / g, about 250 m 2 / g, 250 m 2 / g or more, or any range defined by and including these points (e.g., about 150 m 2From / g to approximately 200m 2 It has a BET surface area of ​​( / g). In at least one embodiment, the BET surface area is at least about 25m². 2 / g, at least about 50m 2 / g, or at least about 75m 2 From / g to approximately 150m 2 It is greater than / g.

[0043] The pore volume and mean pore radius discussed herein are determined by the Barret-Joyner-Halenda (BJH) method. Mercury porosimetry can be used to characterize porosity. In mercury porosimetry, a controlled pressure is applied to a sample immersed in mercury. The application of external pressure causes mercury to penetrate into the voids / pores of the material. The pressure required for penetration into the voids / pores is inversely proportional to the size of the voids / pores. A mercury osmometer generates volume distributions and pore size distributions using the Washburn formula from the pressure-vs-penetration data generated by the instrument:

number

[0044] In at least one embodiment, the adsorbent is approximately 0.5 g / mL, approximately 0.6 g / mL, approximately 0.7 g / mL, approximately 0.8 g / mL, approximately 0.9 g / mL, approximately 1.0 g / mL, approximately 1.1 g / mL, approximately 1.2 g / mL, approximately 1.3 g / mL, approximately 1.4 g / mL, approximately 1.5 g / mL, approximately 1.6 g / mL, approximately 1.7 g / mL, approximately 1.8 g / mL, approximately 1.9 g / mL, approximately It has densities of 2.0 g / mL, approximately 2.1 g / mL, approximately 2.2 g / mL, approximately 2.3 g / mL, approximately 2.4 g / mL, approximately 2.5 g / mL, approximately 2.6 g / mL, approximately 2.7 g / mL, approximately 2.8 g / mL, approximately 2.9 g / mL, approximately 3.0 g / mL, or any range defined by these points and including these (e.g., from approximately 0.7 g / mL to approximately 1.0 g / mL).

[0045] Suitable components contained in the adsorbent composition may exist in bulk form, i.e., in a continuous form not generally interrupted by other materials. The bulk form may be substantially free of other materials. Thus, the adsorbent composition can take any suitable final form of various shapes and sizes, such as spheres, tablets, extruded bodies, pellets, rods, molded articles, monoliths, etc. In at least one embodiment, the adsorbent (e.g., an alumina adsorbent having precipitated or impregnated copper) is in the form of spheres or extruded bodies such as extruded particles. In at least one embodiment, the extruded particles are elongated and may have an average extrusion length (i.e., average maximum dimension) of about 1 mm, about 2 mm, about 3 mm, about 4 mm, about 5 mm, about 6 mm, or any range defined by and including these points (e.g., from about 3 mm to about 5 mm). In at least one embodiment, the adsorbent particles exhibit a lateral compressive strength greater than about 10 N, greater than about 20 N, greater than about 30 N, greater than about 40 N, greater than about 50 N, greater than about 60 N, greater than about 70 N, greater than about 80 N, greater than about 90 N, or greater than about 100 N.

[0046] The adsorbents described herein are suitable for removing chlorides and / or other components from supply streams, such as plastic pyrolysis streams. In this specification, “chloride” refers to chlorine-containing compounds, including, but not limited to, chloroalkanes, chloroalkenes, chlorooxygenates, chloronaphthenes, and chlorinated aromatic compounds. Streams suitable for treatment with the adsorbents described herein may contain chloride content greater than approximately 10 ppmw and less than or equal to approximately 500 ppmw (e.g., approximately 10 ppmw to approximately 45 ppmw, or approximately 100 ppmw to approximately 250 ppmw), or higher.

[0047] In at least one embodiment, the adsorbent exhibits a chloride removal rate of at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%.

[0048] In at least one embodiment, the adsorbent is regenerative (i.e., the adsorbent can be regenerated to restore its activity to or near its pre-use activity). In at least one embodiment, the adsorbent is regenerative by processing in a regeneration stream. In at least one embodiment, the regeneration stream is at a temperature of about 450°C to about 600°C and contains hydrogen gas. In at least one embodiment, the regeneration stream is at a temperature of about 250°C to about 350°C and contains oxygen gas.

[0049] Unless otherwise specified, all parts and percentages are by mass. Unless otherwise specified, mass percentages (mass%) are based on the entire composition excluding volatile substances, i.e., the dry solids content.

[0050] The following are embodiments: Embodiment 1: A method for removing chloride from a plastic pyrolysis stream having an initial chloride concentration of more than about 10 ppmw, comprising contacting the stream with an alumina adsorbent containing a sodium-containing accelerator, wherein the final chloride concentration of the treated stream is less than about 10 ppmw.

[0051] Embodiment 2: The method according to Embodiment 1, wherein the initial chloride concentration is approximately 10 ppmw to approximately 45 ppmw.

[0052] Embodiment 3: The method according to Embodiment 1, wherein the initial chloride concentration is approximately 45 ppmw to approximately 250 ppmw.

[0053] Embodiment 4: The method according to any one of Embodiments 1 to 3, wherein the accelerator is present in an amount of 2% to about 10% by mass based on the total mass of the adsorbent.

[0054] Embodiment 5: The method according to Embodiment 4, wherein the accelerator comprises sodium in the form of Na2O.

[0055] Embodiment 6: The alumina adsorbent is approximately 150 m 2 / g~about 300m 2 The method according to any one of Embodiments 1 to 5, having a BET specific surface area of ​​ / g.

[0056] Embodiment 7: The method according to any one of Embodiments 1 to 6, wherein the alumina adsorbent has a total pore volume of about 0.2 mL / g to about 6 mL / g.

[0057] Embodiment 8: The method according to any one of Embodiments 1 to 7, wherein the alumina adsorbent exhibits a bimodal pore size distribution.

[0058] Embodiment 9: The method according to any one of Embodiments 1 to 8, wherein the alumina adsorbent has a density of about 0.5 g / ml to about 1.0 g / ml.

[0059] Embodiment 10: The method according to any one of Embodiments 1 to 9, wherein the alumina adsorbent is in the form of spherical particles.

[0060] Embodiment 11: The method according to Embodiment 10, wherein the spherical particles have an average diameter of about 2 mm to about 4 mm.

[0061] Embodiment 12: The method according to any one of Embodiments 1 to 11, wherein the spherical particles exhibit a lateral compressive strength exceeding approximately 40 N.

[0062] Embodiment 13: The method according to any one of Embodiments 1 to 12, wherein the chloride removal rate is at least about 80%, at least about 85%, or at least about 90% at a pyrolysis stream temperature of 200°C to 350°C.

[0063] Embodiment 14: The method according to any one of Embodiments 1 to 13, wherein the alumina adsorbent is regenerative.

[0064] Embodiment 15: The method according to any one of Embodiments 1 to 14, further comprising bringing the alumina adsorbent into contact with a regeneration stream to regenerate the alumina adsorbent.

[0065] Embodiment 16: The method according to Embodiment 15, wherein the regeneration stream contains hydrogen gas at a temperature of approximately 450°C to approximately 600°C.

[0066] Embodiment 17: The method according to Embodiment 15, wherein the regeneration stream contains oxygen gas at a temperature of approximately 250°C to approximately 350°C.

[0067] Embodiment 18: A method for removing chloride from a plastic pyrolysis stream having an initial chloride concentration greater than about 10 ppmw, comprising contacting the stream with an adsorbent, wherein the adsorbent comprises copper oxide, zinc oxide, and alumina, and the final chloride concentration of the treated stream is less than about 10 ppmw.

[0068] Embodiment 19: The method according to Embodiment 18, wherein the initial chloride concentration is approximately 10 ppmw to approximately 45 ppmw.

[0069] Embodiment 20: The method according to Embodiment 18, wherein the initial chloride concentration is approximately 45 ppmw to approximately 250 ppmw.

[0070] Embodiment 21: The method according to any one of Embodiments 18 to 20, wherein the copper oxide is present in an amount of about 50% to about 80% by mass based on the total mass of the adsorbent.

[0071] Embodiment 22: The method according to any one of Embodiments 18 to 21, wherein the zinc oxide is present in an amount of about 20% to about 30% by mass based on the total mass of the adsorbent.

[0072] Embodiment 23: The method according to any one of Embodiments 18 to 22, wherein the alumina is present in an amount of about 3% to about 10% by mass based on the total mass of the adsorbent.

[0073] Embodiment 24: The method according to any one of Embodiments 18 to 23, wherein the copper oxide is present in an amount of about 50% to about 80% by mass, the zinc oxide is present in an amount of about 10% to about 40% by mass, and the alumina is present as the remainder of the mass of the adsorbent.

[0074] Embodiment 25: The method according to any one of Embodiments 18 to 24, wherein the adsorbent is formed by coprecipitation of copper oxide and zinc oxide on alumina.

[0075] Embodiment 26: The adsorbent is approximately 25 m 2 / g~about 150m 2 The method according to any one of embodiments 18 to 25, having a BET specific surface area of ​​ / g.

[0076] Embodiment 27: The method according to any one of Embodiments 18 to 26, wherein the adsorbent has a total pore volume of about 0.15 ml / g to about 2 ml / g.

[0077] Embodiment 28: The method according to any one of Embodiments 18 to 27, wherein the adsorbent has a density of about 1.0 g / mL to about 3.0 g / mL.

[0078] Embodiment 29: The method according to any one of Embodiments 18 to 28, wherein the adsorbent is in the form of a tablet.

[0079] Embodiment 30: The method according to Embodiment 29, wherein the tablet has an average length of about 3 mm to about 6 mm and an average width of about 2 mm to about 4 mm.

[0080] Embodiment 31: The method according to Embodiment 29 or 30, wherein the tablet exhibits a lateral compressive strength exceeding approximately 60 N.

[0081] Embodiment 32: The method according to any one of Embodiments 18 to 20, wherein the chloride removal rate is at least about 80%, at least about 85%, or at least about 90% at a pyrolysis stream temperature of 200°C to 350°C.

[0082] Embodiment 33: The method according to any one of Embodiments 18 to 20, wherein the adsorbent is regenerative.

[0083] Embodiment 34: The method according to any one of Embodiments 18 to 20, further comprising bringing the adsorbent into contact with a regeneration stream to regenerate the adsorbent.

[0084] Embodiment 35: The method according to Embodiment 34, wherein the regeneration stream contains hydrogen gas at a temperature of approximately 450°C to approximately 600°C.

[0085] Embodiment 36: The method according to Embodiment 34, wherein the regeneration stream contains oxygen gas at a temperature of approximately 250°C to approximately 350°C. [Examples]

[0086] The following embodiments are provided to aid in understanding this disclosure and should not be construed as particularly limiting the embodiments described herein and claimed. Such modifications of embodiments, including the substitution of all currently known or hereafter developed equivalents that are within the scope of those skilled in the art, as well as minor changes in formulation or experimental design, should be considered within the scope of the embodiments incorporated herein.

[0087] Example 1: Dechlorination performance Standard dechlorination tests were conducted on various samples (described later) using a fluid reactor filled with approximately 1 mL of the specified sample. For dechlorination, a commercially available waste plastic pyrolysis oil (PyOil) sample containing approximately 80 ppmw of chloride (organochlorine compounds) was used. Before each experiment, the reactor was purged with dry nitrogen, and the sample was left for 1000 hours. -1 The material was dehydrated at 250°C for 1 hour at a gas space velocity per hour (GHSV). After dehydration, the liquid PyOil raw material was 1 hr -1 The liquid was introduced into the reactor at a liquid space velocity per hour (LHSV) and a total pressure of 50 bar. To ensure a liquid-only flow, the reactor temperature was raised to 200°C at 50 bar. Chloride levels in the effluent stream were measured at 25°C temperature increases in the range of 200–325°C. Each temperature increase was maintained for approximately 20 hours to equilibrate the system.

[0088] Sample A was a sodium-enhanced alumina formulation with a spherical morphology, a bimodal pore size distribution, and a high macropore volume. While not intended to be theoretically constrained, its unique pore size distribution, characterized by a macropore volume of approximately 0.3 mL / g, was found to contribute to the product's high performance in chloride removal from waste plastic pyrolysis oil. The sodium oxide content was approximately 5.5% by mass relative to the total mass of the formulation.

[0089] Reference 1 was a conventional sodium-enhanced alumina with a spherical morphology and no significant macropore volume (less than 0.05 mL / g) or bimodal pore size distribution. The sodium oxide content was approximately 4% by mass. This composition was found to be inferior to Sample A in its chloride removal performance from waste plastic pyrolysis oil.

[0090] Reference Example 2 was a spherical, conventional non-accelerator-added high-specific-surface-area activated alumina guard. It did not exhibit a significant macropore volume (less than 0.05 ml / g) or a bimodal pore size distribution. This composition was found to have significantly inferior chloride removal performance from waste plastic pyrolysis oil compared to Sample A.

[0091] Sample B was a tablet-form, precipitated copper oxide / zinc oxide-based formulation containing approximately 70% by mass of copper oxide and approximately 24.5% by mass of zinc oxide, with the remainder being alumina. While not intended to be theoretically bound, this formulation is thought to exhibit high performance in chloride removal from waste plastic pyrolysis oil due to its extremely large surface area of ​​copper oxide.

[0092] The characteristics of samples A, B, and the reference sample are summarized in Tables 1 and 2. Figure 1 shows the mercury pore volume distribution of sample A and reference 1, where a prominent macropore volume peak can be observed.

[0093] The chloride removal performance of samples A, B, and the reference sample is shown in Figures 2 and 3.

[0094] Figure 2 shows the performance of samples A and B in chloride removal from waste plastic pyrolysis raw materials. The experimental conditions were a pressure of 50 bar argon, a temperature of 200-325°C, and a commercially available PyOil raw material with a chloride content of 80 ppmw.

[0095] Figure 3 shows the performance of Sample A in removing chlorides from waste plastic pyrolysis raw materials. The experimental conditions were a pressure of 50 bar argon, a temperature of 200-325°C, and a commercially available PyOil raw material with a chloride content of 80 ppmw.

[0096] [Table 1]

[0097] [Table 2]

[0098] The preceding descriptions in this specification include numerous specific details, such as particular materials, dimensions, and process parameters. This is to allow for a full understanding of the embodiments of this disclosure. Certain features, structures, materials, or properties can be combined in any suitable manner in one or more embodiments. In this specification, the terms “example” or “exemplary” mean that they serve as examples, cases, or illustrations. No aspect or design described as “example” or “exemplary” in this specification should be construed as being preferable or advantageous to any other aspect or design. Rather, the use of the terms “example” or “exemplary” is intended to present a concept in a concrete form. The terms “or” as used in this application are intended to mean inclusive “or” rather than exclusive “or.” That is, unless otherwise specified or evident from the context, “X includes A or B” means any of the natural inclusive permutations. That is, if X includes A, if X includes B, or if X includes both A and B, the condition “X includes A or B” is satisfied in all cases.

[0099] Furthermore, the use of “a,” “an,” “the,” and similar reference terms in the context describing the materials and methods described herein (particularly in the following claims) shall be interpreted as encompassing both singular and plural forms, unless otherwise stated herein or unless clearly contradicted by the context.

[0100] The descriptions of value ranges in this specification are intended as a concise way of referring individually to the individual values ​​contained within those ranges, unless otherwise specified, and each individual value is incorporated into the specification as if it were described individually. All methods described herein may be performed in any suitable order, unless otherwise specified or unless it is clearly inconsistent with the context. Furthermore, any permutation of the listed values ​​is assumed to define the boundaries of the ranges. For example, the range from 1, 2, or 3 to 4, 5, or 6 is understood to include not only 1 to 4, 1 to 5, 1 to 6, 2 to 4, 2 to 5, etc., but also 1 to 2, 1 to 3, 2 to 3, 4 to 6, etc.

[0101] Throughout this specification, the term “approximately” is used to account for and account for small variations (e.g., ±1%) that may arise due to experimental or measurement errors. Whether explicitly stated or not, all numerical values ​​are modified by the term “approximately.” Numerical values ​​modified by the term “approximately” include a specified identifier. For example, “approximately 5.0” includes 5.0.

[0102] The terms “essentially absent,” “substantially absent,” or “substantially not contained” mean “not intentionally added,” and may be present in trace or accidental amounts, for example, ≤5% by mass, ≤4% by mass, ≤3% by mass, ≤2% by mass, ≤1% by mass, ≤0.5% by mass, or ≤0.25% by mass, based on the total mass of the composition in question, e.g., the adsorbent composition. For example, a substantially lead-free adsorbent composition may refer to an adsorbent composition in which lead is below the detection limit, or an adsorbent composition in which its presence has only a negligible effect on the performance of the adsorbent.

[0103] Throughout this specification, the expressions “one embodiment,” “a particular embodiment,” “one or more embodiments,” “embodiment,” or “some embodiments” mean that a particular feature, structure, material, or property described in relation to that embodiment is included in at least one embodiment. Therefore, expressions such as “in one or more embodiments,” “in a particular embodiment,” “in one embodiment,” or “in some embodiments” appearing in various places in this specification do not necessarily refer to the same embodiment of this disclosure. Furthermore, particular features, structures, materials, or properties can be combined in any suitable way in one or more embodiments.

[0104] It should be understood that the above description is illustrative and not limiting. Those skilled in the art will be able to clearly recognize many other embodiments by reading and understanding the above description. Therefore, the scope of this specification should be determined by referring to the entirety of the appended claims and their equivalent scopes. Any examples or illustrative expressions (e.g., “for example”) described herein are intended merely to provide a clearer description of the materials and methods and do not constitute a limitation on their scope unless otherwise requested. No expression in the specification should be construed as indicating that an unclaimed element is essential for carrying out the disclosed materials and methods.

[0105] While the embodiments disclosed herein are described with reference to specific embodiments, it should be understood that these embodiments merely illustrate the principles and applications of the disclosure. Those skilled in the art will understand that various modifications and variations are possible to the methods and apparatus of the disclosure without departing from the spirit and scope of the disclosure. Accordingly, the disclosure is intended to include modifications and variations within the scope of the appended claims and their equivalents, and the embodiments described above are presented for illustrative purposes only, not limitation.

Claims

1. A method for removing chlorides from a plastic pyrolysis stream having an initial chloride concentration exceeding approximately 10 ppm W, A method comprising contacting the stream with an alumina adsorbent containing a sodium-containing accelerator, wherein the final chloride concentration of the treated stream is less than approximately 10 ppmW.

2. The method according to claim 1, wherein the initial chloride concentration is approximately 10 ppmw to approximately 45 ppmw.

3. The method according to claim 1, wherein the initial chloride concentration is approximately 45 ppmW to approximately 250 ppmW.

4. The method according to claim 1, wherein the accelerator is present in an amount of 2% to about 10% by mass based on the total mass of the adsorbent.

5. The aforementioned promoter is Na ２ The method according to claim 4, comprising sodium in the form of O.

6. The alumina adsorbent is approximately 150 m ２ / g ~ approx. 300m ２ The method according to claim 1, having a BET specific surface area of ​​1 / g.

7. The method according to claim 1, wherein the alumina adsorbent has a total pore volume of about 0.2 mL / g to about 6 mL / g.

8. The method according to claim 1, wherein the alumina adsorbent exhibits a bimodal pore size distribution.

9. The method according to claim 1, wherein the alumina adsorbent has a density of about 0.5 g / ml to about 1.0 g / ml.

10. The method according to claim 1, wherein the alumina adsorbent is in the form of spherical particles.

11. The method according to claim 10, wherein the spherical particles have an average diameter of about 2 mm to about 4 mm.

12. The method according to claim 10, wherein the spherical particles exhibit a lateral compressive strength exceeding approximately 40 N.

13. The method according to claim 1, wherein the chloride removal rate is at least about 80%, at least about 85%, or at least about 90% at a thermal decomposition stream temperature of 200°C to 350°C.

14. The method according to claim 1, wherein the alumina adsorbent is regenerative.

15. The method according to claim 1, further comprising bringing the alumina adsorbent into contact with a regeneration stream to regenerate the alumina adsorbent.

16. The method according to claim 15, wherein the regeneration stream contains hydrogen gas at a temperature of about 450°C to about 600°C.

17. The method according to claim 15, wherein the regeneration stream contains oxygen gas at a temperature of about 250°C to about 350°C.

18. A method for removing chlorides from a plastic pyrolysis stream having an initial chloride concentration exceeding approximately 10 ppm W, A method comprising contacting the stream with an adsorbent, wherein the adsorbent comprises copper oxide, zinc oxide, and alumina, and the final chloride concentration of the treated stream is less than about 10 ppmW.

19. The method according to claim 18, wherein the initial chloride concentration is approximately 10 ppmw to approximately 45 ppmw.

20. The method according to claim 18, wherein the initial chloride concentration is approximately 45 ppmw to approximately 250 ppmw.

21. The method according to claim 18, wherein the copper oxide is present in an amount of about 50% to about 80% by mass based on the total mass of the adsorbent.

22. The method according to claim 18, wherein the zinc oxide is present in an amount of about 20% to about 30% by mass based on the total mass of the adsorbent.

23. The method according to claim 18, wherein the alumina is present in an amount of about 3% to about 10% by mass based on the total mass of the adsorbent.

24. The copper oxide is present in an amount of approximately 50% to approximately 80% by mass. The zinc oxide is present in an amount of approximately 10% to approximately 40% by mass, and The method according to claim 18, wherein the alumina is present as the remaining mass of the adsorbent.

25. The method according to claim 18, wherein the adsorbent is formed by coprecipitation of copper oxide and zinc oxide on alumina.

26. The adsorbent is approximately 25 m ２ / g ~ approx. 150m ２ The method according to claim 18, having a BET specific surface area of ​​1 / g.

27. The method according to claim 18, wherein the adsorbent has a total pore volume of about 0.15 ml / g to about 2 ml / g.

28. The method according to claim 18, wherein the adsorbent has a density of about 1.0 g / mL to about 3.0 g / mL.

29. The method according to claim 18, wherein the adsorbent is in the form of a tablet.

30. The method according to claim 29, wherein the tablet has an average length of about 3 mm to about 6 mm and an average width of about 2 mm to about 4 mm.

31. The method according to claim 29, wherein the tablet exhibits a lateral compressive strength exceeding approximately 60 N.

32. The method according to claim 18, wherein the chloride removal rate is at least about 80%, at least about 85%, or at least about 90% at a thermal decomposition stream temperature of 200°C to 350°C.

33. The method according to claim 18, wherein the adsorbent is regenerative.

34. The method according to claim 18, further comprising bringing the adsorbent into contact with a regeneration stream to regenerate the adsorbent.

35. The method according to claim 34, wherein the regeneration stream contains hydrogen gas at a temperature of approximately 450°C to approximately 600°C.

36. The method according to claim 34, wherein the regeneration stream contains oxygen gas at a temperature of approximately 250°C to approximately 350°C.

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