Process for converting saturated polyethylene to olefin products

Abstract

The present disclosure relates to processes for converting saturated polyethylene to at least one olefin product. The process comprises contacting the saturated polyethylene with three or more catalyst components in a reactor, the reactor comprising olefin reactants. The three or more catalyst components include a metathesis catalyst component, an isomerization catalyst component, and a dehydrogenation catalyst component. The contacting causes at least a portion of the saturated polyethylene to undergo a dehydrogenation reaction to form an unsaturated polyethylene, and at least a portion of the unsaturated polyethylene, or a product derived therefrom, to undergo a metathesis reaction and an isomerization reaction to produce an effluent comprising at least the olefinic product.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 353,320, filed on June 17, 2022, the entire disclosure of which is hereby incorporated by reference into this document. Background Art Technical Field

[0003] The present disclosure relates to chemical processing of hydrocarbons. In particular, the present disclosure relates to processes for converting ethylene-containing materials such as polyethylene into smaller desired hydrocarbon products. Background Art

[0004] For many industrial applications, hydrocarbons are used for or as starting materials to produce plastics, fuels and various downstream chemicals. Such hydrocarbons include olefins, such as ethene, propene and butene (also commonly referred to as ethylene, propylene and butylene, respectively). A variety of methods have been developed for the production of these lower hydrocarbons, including petroleum cracking and various synthesis methods. Polyethylene (PE) is the most widely used plastic in the world and can be made into various products. However, it is desirable to recycle polyethylene into a method for smaller monomers such as propylene. Conventional efforts for chemical recycling of polyethylene usually use pyrolysis and high temperature thermal degradation. These methods are highly energy intensive and are subject to the low selectivity of the desired product and the trouble of greenhouse gas (e.g., CO , CH ) generation. Summary of the invention

[0005] Embodiments of the present disclosure address these and other needs by providing methods for converting polyethylene into olefin products. The methods described herein can enable three or more catalyst components in a reactor system to perform a variety of different chemical reactions, such as a combination of dehydrogenation, metathesis, and isomerization for producing olefin products, for example, from saturated polyethylene and olefin reactants.

[0006] According to one or more other aspects of the present disclosure, a method for converting saturated polyethylene into at least one m H 2m A process for producing an olefin product comprising contacting saturated polyethylene with three or more catalyst components in a reactor, the reactor comprising a n H 2nThe contacting causes at least a portion of the saturated polyethylene to undergo a dehydrogenation reaction to form an unsaturated polyethylene, and at least a portion of the unsaturated polyethylene or a product derived therefrom to undergo a metathesis reaction and an isomerization reaction to produce at least one olefin reactant having a chemical formula of C m H 2m The effluent is an olefin product.

[0007] Additional features and advantages will be set forth in the following Detailed Description, and in part will become apparent to those skilled in the art from that description or may be learned by practicing the embodiments described herein, including the following Detailed Description and claims.

[0008] It is to be understood that both the foregoing general description and the following detailed description describe various embodiments, and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 schematically depicts a reactor according to one or more embodiments of the present disclosure;

[0010] For description Figure 1 For purposes of simplified schematics and description, many valves, temperature sensors, electronic controllers, etc. that may be employed in certain chemical processing operations and are well known to those of ordinary skill in the art are not included. In addition, accompanying components that are typically included in typical chemical processing operations, carrier gas supply systems, pumps, compressors, furnaces, or other subsystems are not depicted. It should be understood that these components are within the spirit and scope of the disclosed embodiments of the present invention. However, operating components (such as those described in the present disclosure) may be added to the embodiments described in the present disclosure. DETAILED DESCRIPTION

[0011] Some conventional methods for converting polyethylene into smaller products may use separate catalysts separated in separate catalyst zones, such as by loading each of the separate catalysts into separate reactors, which may increase the initial capital cost of the reaction system. In contrast, the methods disclosed herein can achieve tandem catalysis of polyethylene by contacting polyethylene with mutually compatible catalyst components to produce desired olefin products. Catalytic depolymerization of polyethylene under mild reaction conditions provides an advantageous and sustainable alternative for producing hydrocarbon feedstocks, monomers or other usable chemicals.

[0012] Reference will now be made in detail to an embodiment of a process for converting saturated polyethylene into olefin products in a reactor. As used herein, "saturated polyethylene" refers to a polyethylene comprising the formula C x H 2x+2 wherein x is an integer of at least 10, and wherein the carbon-carbon bond is a single bond. In an embodiment, the saturated polyethylene may include a branched polyethylene. In an embodiment, the saturated polyethylene may include a linear low density polyethylene (LLDPE), a low density polyethylene (LDPE), or a combination thereof. In an embodiment, the saturated polyethylene may include a polyethylene having the formula CH3(C2H4) x In an embodiment, the saturated polyethylene comprises C x H 2x+2 , wherein x is an integer greater than or equal to 10, greater than or equal to 12, or even greater than or equal to 15. In an embodiment, the saturated polyethylene may have a number average molecular weight (M) of 150 g / mol to 1,000,000 g / mol. n ). In embodiments, the saturated polyethylene may be a waste stream of a hydrocarbon processing system or a product derived therefrom.

[0013] In embodiments, the reactor comprises an olefin reactant. In embodiments, the olefin reactant has the formula C n H 2n , wherein n is an integer from 2 to 20. For example, the olefin reactant may have the formula C n H 2n , wherein n is an integer from 2 to 15, 2 to 10, 2 to 5, 2 to 4 or 2 to 3. In an embodiment, the olefin reactant may include ethylene, propylene, butene, pentene or a combination thereof. In an embodiment, the olefin reactant may be selected from the group consisting of ethylene, propylene, butene, pentene and a combination thereof. In an embodiment, the olefin reactant may include ethylene. In an embodiment, the olefin reactant may be substantially composed of ethylene or composed of ethylene. In an embodiment, the olefin reactant may include ethylene and butene. In an embodiment, the olefin reactant may be substantially composed of ethylene and butene or composed of ethylene and butene.

[0014] In an embodiment, the saturated polyethylene may be contacted with three or more catalyst components in a reactor. As used herein, "catalyst component" refers to any substance that increases the rate of a particular chemical reaction. Catalyst components and catalyst compositions made with the catalyst components described in the present disclosure can be used to promote various reactions, such as but not limited to dehydrogenation, metathesis, isomerization, or a combination of these. In an embodiment, the catalyst composition may include at least one catalyst component, at least two catalyst components, or at least three catalyst components. As used herein, "catalyst composition" refers to solid particles comprising at least one catalyst component. The catalyst composition may also include a catalyst support material.

[0015] In embodiments, the catalyst component may include a dehydrogenation catalyst component, a metathesis catalyst component and an isomerization catalyst component. Without wishing to be bound by any particular theory, it is believed that a dehydrogenation catalyst can introduce unsaturates in the carbon chain of saturated polyethylene to produce unsaturated polyethylene. It is believed that in the presence of an olefin reactant, a metathesis catalyst can break the carbon chain of unsaturated polyethylene to produce two products with terminal unsaturates respectively, and the further metathesis of the terminal unsaturated polyethylene intermediate product and the olefin reactant may be unhelpful for further breaking the carbon chain. It is believed that an isomerization catalyst component can convert terminal unsaturates into internal unsaturates, and isomerized products can be further decomposed into two products in the presence of a metathesis catalyst component and an olefin reactant. The cycle can continue until desired products or product groups are produced from the process.

[0016] In an embodiment, the dehydrogenation catalyst component is operable to convert saturated polyethylene into unsaturated polyethylene. In an embodiment, the dehydrogenation catalyst component can cause saturated polyethylene or a product derived therefrom to have additional unsaturated substances along the polyethylene backbone. In an embodiment, the dehydrogenation catalyst component can cause saturated polyethylene or a product derived therefrom to undergo transfer dehydrogenation. In an embodiment, the dehydrogenation catalyst component may include one or more elements selected from Groups 5-10 of the International Union of Pure and Applied Chemistry (IUPAC). In an embodiment, the dehydrogenation catalyst component may include platinum, iridium, ruthenium, rhenium, or a combination thereof. In an embodiment, the dehydrogenation catalyst component is selected from the group consisting of platinum, iridium, ruthenium, rhenium, and a combination thereof.

[0017] In an embodiment, a metathesis catalyst component in combination with an olefin reactant such as ethylene can be operated to break an unsaturated polyethylene chain into two species. In an embodiment, a metathesis catalyst component can break an olefin product derived from saturated polyethylene. In an embodiment, a metathesis catalyst component may include one or more elements selected from the 5th to 10th groups of the International Union of Pure and Applied Chemistry (IUPAC). In an embodiment, a metathesis catalyst component may include rhenium, ruthenium, tungsten, molybdenum, vanadium, or a combination thereof. In an embodiment, a metathesis catalyst component may be selected from the group consisting of rhenium, ruthenium, tungsten, molybdenum, vanadium, and a combination thereof. In an embodiment, a metathesis catalyst component may include methyltrioxorhenium (MTO).

[0018] In an embodiment, the isomerization catalyst component is operable to move the unsaturated on the unsaturated polyethylene or the unsaturated on the product derived therefrom from one position on the main chain to a different position. For example, in an embodiment, the isomerization catalyst component can move the unsaturated in the terminal position of the unsaturated polyethylene to an internal position. In an embodiment, the isomerization catalyst component may include one or more elements selected from the 5th to 10th groups of the International Union of Pure and Applied Chemistry (IUPAC). In an embodiment, the isomerization catalyst component may include aluminum oxide, silicon dioxide, iridium, palladium, ruthenium or a combination thereof. In an embodiment, the isomerization catalyst component may be selected from the group consisting of aluminum oxide, silicon dioxide, iridium, palladium, ruthenium and a combination thereof. In an embodiment, the isomerization catalyst component may include modified aluminum oxide, modified silicon dioxide or a combination thereof. For example, in an embodiment, the isomerization catalyst component may include but is not limited to chlorinated aluminum oxide, γ-aluminum oxide, chlorinated silicon dioxide or a combination thereof. In an embodiment, the isomerization catalyst component may include [tert-butyl-POCOP] Ir[C2H4].

[0019] In embodiments, the reactor may include one or more catalyst compositions comprising three or more catalyst components. For example, in embodiments, the catalyst composition may include a metathesis catalyst component and an isomerization catalyst component. In embodiments, the catalyst composition may include a dehydrogenation catalyst component and an isomerization catalyst component. In embodiments, the catalyst composition may include a metathesis catalyst component and an isomerization catalyst component. In embodiments, the catalyst composition may include a dehydrogenation catalyst component and a metathesis catalyst component. In embodiments, the catalyst composition may include a dehydrogenation catalyst component and a metathesis catalyst component. In embodiments, the catalyst composition may include a dehydrogenation catalyst component, a metathesis catalyst component, and an isomerization catalyst component. In embodiments, the catalyst composition may include a dehydrogenation catalyst component, a metathesis catalyst component, and an isomerization catalyst component. In embodiments, the catalyst composition may include a dehydrogenation catalyst component, a metathesis catalyst component, or an isomerization catalyst component. In embodiments, the reactor may include a first catalyst composition comprising a metathesis catalyst component and an isomerization catalyst component. For example, in embodiments, the reactor may include a first catalyst component, wherein the first catalyst component is MTO on alumina. In embodiments, the reactor may include a second catalyst composition, wherein the second catalyst component may include platinum on alumina or platinum on silica. In an embodiment, a first catalyst composition comprising MTO on alumina and a second catalyst composition comprising platinum on alumina can contact saturated polyethylene in a reactor. In other embodiments, a first catalyst composition comprising MTO on alumina and a second catalyst composition comprising [tert-butyl-POCOP]Ir[C2H4] can contact saturated polyethylene in a reactor.

[0020] In an embodiment, the catalytic composition is specified by a certain weight percentage of one or more elements selected from the International Union of Pure and Applied Chemistry (IUPAC) Groups 5-10. In an embodiment, the first catalyst composition may include less than or equal to 15 weight % of any one of the elements selected from IUPAC Groups 5-10, based on the total weight of the first catalyst composition. For example, in an embodiment, the first catalyst composition may include less than or equal to 12 weight %, less than or equal to 10 weight %, less than or equal to 8 weight %, less than or equal to 6 weight %, less than or equal to 4 weight %, or even less than or equal to 2 weight % of any one of the elements selected from IUPAC Groups 5-10, based on the total weight of the first catalyst composition. In an embodiment, the first catalyst composition may include greater than 1 weight %, greater than 2 weight %, greater than 3 weight %, greater than 4 weight %, greater than 5 weight %, greater than 6 weight %, greater than 7 weight %, greater than 8 weight %, or even greater than 9 weight % of any one of the elements selected from IUPAC Groups 5-10, based on the total weight of the first catalyst composition. In an embodiment, the first catalyst composition may comprise any one element selected from IUPAC Groups 5-10 in an amount of 1 wt % to 15 wt %, 1 wt % to 12 wt %, 1 wt % to 10 wt %, 1 wt % to 5 wt %, 1 wt % to 4 wt %, 2 wt % to 15 wt %, 2 wt % to 12 wt %, 2 wt % to 10 wt %, 2 wt % to 5 wt %, 2 wt % to 4 wt %, 5 wt % to 15 wt %, 5 wt % to 12 wt %, or 5 wt % to 10 wt %, based on the total weight of the first catalyst composition.

[0021] In an embodiment, the second catalyst composition may include less than or equal to 15 wt % of any one of the elements selected from IUPAC Groups 5-10, based on the total weight of the second catalyst composition. For example, in an embodiment, the second catalyst composition may include less than or equal to 12 wt %, less than or equal to 10 wt %, less than or equal to 8 wt %, less than or equal to 6 wt %, less than or equal to 4 wt %, or even less than or equal to 2 wt % of any one of the elements selected from IUPAC Groups 5-10, based on the total weight of the second catalyst composition. In an embodiment, the second catalyst composition may include greater than 1 wt %, greater than 2 wt %, greater than 3 wt %, greater than 4 wt %, greater than 5 wt %, greater than 6 wt %, greater than 7 wt %, greater than 8 wt %, or even greater than 9 wt % of any one of the elements selected from IUPAC Groups 5-10, based on the total weight of the second catalyst composition. In an embodiment, the second catalyst composition may comprise any one element selected from IUPAC Groups 5-10 in an amount of 1 wt % to 15 wt %, 1 wt % to 12 wt %, 1 wt % to 10 wt %, 1 wt % to 5 wt %, 1 wt % to 4 wt %, 2 wt % to 15 wt %, 2 wt % to 12 wt %, 2 wt % to 10 wt %, 2 wt % to 5 wt %, 2 wt % to 4 wt %, 5 wt % to 15 wt %, 5 wt % to 12 wt %, or 5 wt % to 10 wt %, based on the total weight of the second catalyst composition.

[0022] It should be understood that, depending on the embodiment, the catalyst composition can be prepared by a process that produces the desired composition. Some non-limiting examples include incipient wetness impregnation or vapor deposition of a metal precursor (organic or inorganic in nature) followed by controlled decomposition thereof.

[0023] In embodiments, contacting the saturated polyethylene with three or more catalyst components in a reactor containing an olefin reactant may result in at least a portion of the saturated polyethylene undergoing a dehydrogenation reaction to form an unsaturated polyethylene, and at least a portion of the unsaturated polyethylene or products derived therefrom undergoing a metathesis reaction and an isomerization reaction to produce at least one of the formula C m H 2mThe effluent of the olefin product. For example, the contact of saturated polyethylene with a dehydrogenation catalyst component can dehydrogenate the saturated polyethylene, which introduces at least one unsaturated substance into the main chain of the polyethylene to form unsaturated polyethylene. In an embodiment, the unsaturated polyethylene can contact the metathesis catalyst component in the presence of an olefin reactant to break the unsaturated polyethylene to form two products, wherein each product comprises terminal unsaturated polyethylene. The terminal unsaturated polyethylene can contact the isomerization catalyst component to cause the unsaturated substance in the terminal unsaturated polyethylene to move from the terminal position to the internal position to form an internal unsaturated polyethylene. Without wishing to be bound by any particular theory, it is believed that the internal unsaturated polyethylene can undergo further metathesis reaction by contacting the metathesis catalyst component in the presence of an olefin reactant. It is believed that the product derived from the unsaturated polyethylene contacting the metathesis catalyst component and the isomerization catalyst component in the presence of an olefin reactant can continue to circulate between the metathesis and isomerization reactions to produce smaller olefin products, such as a chemical formula of C m H 2m wherein m is an integer from 3 to 20, such as propylene. In an embodiment, the reaction time may be increased to produce an effluent comprising smaller olefin products, as the increased reaction time will allow for additional metathesis and isomerization reaction cycles.

[0024] In an embodiment, the reactor can be any reactor that can be used to contact three or more catalyst components in the presence of olefin reactants with polyethylene and to carry out the catalytic reaction, such as a batch reactor, a fixed bed reactor, a fluidized bed reactor, a continuous stirred tank reactor, a tubular plug flow reactor, a reaction extruder, or a combination thereof. In an embodiment, two or more reactors can be used, such as two or more reactors in series. In an embodiment, the reactor may include a reaction zone, in which contact and catalytic reaction may occur. In an embodiment, three or more catalyst components may be in the same reaction zone. In other embodiments, the reactor may include two or more reaction zones. In an embodiment, the reactor may include additional processing of reactants, such as processing of olefin reactants, saturated polyethylene and / or catalyst components. In an embodiment, the effluent containing one or more products from the catalytic reaction may be further processed, such as separating one or more products from the effluent. For example, in an embodiment, propylene may be separated from the effluent.

[0025] In embodiments, the pressure of the olefin reactant in the reactor (such as in the reaction zone) during contact can be 0 pounds per square inch gauge (psig) to 3000psig. For example, the pressure of the olefin reactant can be 0psig to 3000psig, 0psig to 2000psig, 0psig to 1000psig, 0psig to 900psig, 0psig to 800psig, 0psig to 700psig, 0psig to 600psig, 0psig to 500psig or 100psig to 3000psig. In some embodiments, the amount of the olefin reactant used can be quantified by the pressure of the olefin reactant in the reactor. In other embodiments, the amount of the olefin reactant can be quantified by the space velocity of the olefin reactant.

[0026] In embodiments, the temperature of the reactor (such as in the reaction zone) during contacting may be less than or equal to 400°C. For example, the temperature of the reactor during contacting may be less than or equal to 350°C, less than or equal to 300°C, less than or equal to 250°C, or even less than or equal to 200°C. In embodiments, the temperature of the reactor during contacting may be from 50°C to 400°C, from 50°C to 350°C, from 50°C to 300°C, from 50°C to 250°C, from 50°C to 200°C, from 60°C to 400°C, from 60°C to 350°C, from 60°C to 300°C, from 60°C to 250°C, or from 60°C to 200°C. Without wishing to be bound by any particular theory, it is believed that a reduced reactor temperature (such as less than or equal to 400°C, less than or equal to 350°C, less than or equal to 300°C, less than or equal to 250°C, or less than or equal to 200°C) may reduce the formation of undesirable byproducts during contacting. Furthermore, the reduced operating temperature of the reactor can reduce the energy required for the process, which can also reduce the economic cost of operation.

[0027] In an embodiment, the contacting causes at least a portion of the saturated polyethylene to undergo a catalytic reaction to produce an effluent. In an embodiment, the effluent may comprise hydrocarbons having an average molecular weight of 40 g / mol to 1000 g / mol. In an embodiment, the effluent may comprise at least a m H 2m In an embodiment, the olefin product is an olefin product of the formula C m H 2m wherein m is an integer from 3 to 20. For example, the olefin product may be a compound of formula C m H 2mThe compound wherein m is an integer of 3 to 15, 3 to 10, 3 to 8, 3 to 7, 3 to 6, 3 to 5, 3 to 4 or 3. In an embodiment, the olefin product may include propylene, butenes, pentenes or a combination thereof. In an embodiment, the olefin product may be selected from the group consisting of propylene, butenes, pentenes and a combination thereof. In an embodiment, the olefin product may be substantially composed of propylene, butenes, pentenes or a combination thereof or may be composed of propylene, butenes, pentenes or a combination thereof. In an embodiment, the olefin product may be substantially composed of propylene or may be composed of propylene.

[0028] In embodiments, the effluent may comprise at least 1 wt%, at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 45 wt%, at least 50 wt%, at least 55 wt%, or even at least 60 wt% olefin product.

[0029] Example

[0030] Various aspects of the present disclosure will be further illustrated by the following examples. The examples are illustrative in nature and should not be construed as limiting the subject matter of the present disclosure. In Examples 1-7, catalysts according to the present disclosure were prepared. The materials used in these examples are provided in Table 1 below.

[0031] Table 1

[0032]

[0033] In Example 8-10, the catalytic method according to the present disclosure is carried out in a batch reactor. The hydrocarbons in the gas fraction product (C1-C6) are quantitatively analyzed on a Shimadzu GC-2010 gas chromatograph equipped with a capillary column (Supelco Alumina Sulfate plot, 30m×0.32mm) and a flame ionization detector (FID). The signal coefficient depends on the carbon number of each hydrocarbon substance. The injector and detector temperature are 200°C. The temperature ramp program is as follows: 90°C (holding 3 minutes), 10°C / min ramping to 150°C (holding 20 minutes). Helium is used as a carrier gas. H2, C2H4 and C2H6 are quantitatively measured on a Shimadzu GC-8AIT gas chromatograph equipped with a packed column (ShinCarbon ST 80 / 100, 2m×2mm) and a thermal conductivity detector (TCD). The linear response of the TCD signal to the injection volume of H2, C2H4 and C2H6 is confirmed using a standard gas mixture. The response factor was obtained as the slope of the fitted line. The column, injector and detector temperatures were 130°C. The TCD current was 70 mA and the carrier gas pressure was 300 kPa (N2). The liquid products (>C5) were analyzed on an Agilent 6890N network gas chromatograph equipped with a DB-5 column and a FID detector.

[0034] Example 1. Preparation of CH3ReO3 / Cl-Al2O3 Catalyst Composition

[0035] The catalyst composition of Example 1, 4 wt% CH3ReO3 / Cl-Al2O3, was synthesized using the following protocol: γ-Al2O3 (Strem Chemicals) was calcined at 550°C for 4 hours (h) in air and then heated to room temperature under dynamic vacuum (10 -4 The partially dehydrated and dehydroxylated alumina was chlorinated in a CCl4 saturated Ar flow (Air Gas Company, UHP, 10 mL / min) in a fixed bed reactor at 300°C for 1 h. The CCl4 was distilled before use. The resulting Cl-Al2O3 was evacuated at 450°C overnight and vacuum sublimed at room temperature (ca. 10 -4 Torr) was modified with CH3ReO3 (MTO, Sigma-Aldrich) to obtain a material containing 4 wt% MTO and 4 wt% Cl based on the total weight of the material. The solid was periodically shaken vigorously to promote uniform deposition of MTO. After grafting MTO onto Cl-Al2O3, the catalyst was evacuated at room temperature for 30 minutes to remove physically adsorbed materials, and the catalyst was stored in a N2-filled glove box to prevent deactivation in air.

[0036] Example 2. Preparation of 1.5% Pt / γ-Al2O3 Catalyst Composition

[0037] The catalytic composition 1.5% Pt / γ-Al2O3 of Example 2 was synthesized using the following protocol: γ-Al2O3 (Strem Chemical Company, 186 m 2 g -1 , pore volume 0.50cm 3 g -1 ) was calcined in air at 500°C for 4 hours and then evacuated at 450°C for 10 -4 Torr) for 12 hours. -4 Volatile trimethyl (cyclopentadienyl) platinum (32 ± 1 mg) was deposited onto dry alumina (1.300 ± 0.020 g) to obtain a material with 1.5 wt % Pt. The reactor was shaken vigorously during the process to promote uniform deposition, followed by evacuation at room temperature for 1 hour to remove physically adsorbed PtCp (CH ) . When the temperature was ramped to 250° C. at a rate of 2° C. / min, the resulting solid was reduced in flowing H (4.0% in Ar, 30 mL / min). The material was kept at this temperature for 2 h, then cooled to room temperature and evacuated for 15 minutes. The reduced catalyst was stored in a N filled glove box until use to avoid reoxidation in air.

[0038] Example 3. Preparation of 1.5% Pt / Cl-Al2O3 Catalyst Composition

[0039] The catalytic composition 1.5% Pt / Cl-Al2O3 of Example 3 was synthesized using the following protocol: γ-Al2O3 (Strem Chemical Company, 186 m 2 g -1 , pore volume 0.50cm 3 g -1 ) was calcined at 500°C for 4 hours in air. 1.5 g of the calcined alumina was impregnated with 0.6 ml of an aqueous solution containing 45.0 mg of Pt(NH3)4(NO3)2 and 46 mg of HCl (from concentrated HCl), then dried in an oven at 80°C for 2 hours and calcined at 500°C for 3 hours under static air at a ramp rate of 2°C / min. The resulting material was then reduced at 280°C for 2 hours under H2 at a ramp rate of 2°C / min (5.0% in Ar, 30 mL / min), then heated at about 10 °C for 3 hours. -4 The reduced catalyst was stored in a N2-filled glove box until use to avoid reoxidation in air.

[0040] Example 4. Preparation of 1.5% Pt / SiO2 Catalyst Composition

[0041] The catalytic composition 1.5% Pt / SiO2 of Example 4 was synthesized using the following protocol: 1.5 g of calcined SiO2 (Sylopol 952) was impregnated with 1.5 mL of an aqueous solution containing 45.0 mg of Pt(NH3)4(NO3)2, followed by drying in an oven at 80°C overnight and calcining at 350°C for 3 hours under static air at a ramp rate of 2°C / min. The resulting material was then reduced at 280°C for 2 hours under 5.0% H2 / Ar at a ramp rate of 2°C / min, followed by heating at about 10 °C. -4 The catalyst containing 1.5 wt % Pt was stored in a N2-filled glove box until use to avoid reoxidation in air.

[0042] Example 5. Preparation of Re2O7 / γ-Al2O3 catalyst composition

[0043] The catalyst composition Re2O7 / γ-Al2O3 of Example 5 was synthesized using the following protocol: Re2O7 / γ-Al2O3 was prepared by incipient wetness impregnation of γ-Al2O3 (Strem Chemical Company) with ammonium perrhenate to obtain a material containing 10 wt% Re. Prior to impregnation, γ-Al2O3 was calcined at 550°C for 4 h within 2 h. After impregnation, the dried material was activated by calcination at 650°C for 8 h in oxygen at 5°C / min. The calcined catalyst was stored in a N2-filled glove box until use to avoid deactivation in air.

[0044] Example 6. Preparation of PtRe / SiO2 catalyst composition

[0045] The catalytic composition PtRe / SiO2 of Example 6 was prepared using the following procedure: PtRe / SiO2 was prepared by incipient wetness impregnation of silica powder with ammonium perrhenate to obtain a material containing 1 wt%-5 wt% Re. After impregnation, the material was calcined at 500°C. Pt was deposited on the material by incipient wetness impregnation with platinum acetylacetonate in toluene to obtain a material containing 1 wt%-5 wt% Pt. The resulting solid was dried in air at 120°C for 4 h, after which the temperature was increased to 210°C for 4 h. The material was reduced in H2 at 150°C for 1 hour. The reduced catalyst was stored in a N2 atmosphere until use to avoid reoxidation in air. The PtRe / SiO2 catalyst was calcined at 500°C for 4 h and then reduced with H2 at 280°C for 2 h. The heating rate was 2°C / min. After reduction, the catalyst was evacuated at room temperature for 30 min to remove physically adsorbed H 2 , and stored in a N 2 -filled glove box to prevent deactivation in air.

[0046] Example 7. tBu Preparation of POCOP]Ir[C2H4] Catalytic Composition

[0047] The catalytic composition of Example 7 [ tBuPOCOP]Ir[C2H4] was prepared according to "Catalytic Alkane Metathesis by Tandem Alkane Dehydrogenation-Olefin Metathesis" Science 2006, 312, 257-261. [C6H3-2,6-[OP(t-Bu)2]2]Ir[H][Cl] and NaO-t-Bu were weighed into an oven-dried Schlenk flask at a molar ratio of 1:1.2, respectively. The solid was then placed under an argon stream. 40 mL of toluene was added to the flask via a syringe, and the resulting suspension was stirred at room temperature for 10 minutes. Ethylene was bubbled through the solution for 1-2 hours. The solution was cannulated filtered through a diatomaceous earth pad, volatiles were evaporated under vacuum, and the resulting red solid was dried overnight under vacuum to obtain a product in 60% yield.

[0048] Example 8. Catalytic conversion of saturated polyethylene to olefins in a batch reactor

[0049] In Example 8, saturated polyethylene and ethylene react in a 25mL batch reactor (Parr reactor, series 4590) on the catalyst of Example 2 and Example 5. In a glove box filled with N2, 199mg of Example 5, 199mg of Example 2 and 120mg of saturated polyethylene are loaded into a 25mL reactor equipped with a pressure gauge and a K-type thermocouple. Before use, ethylene (99.999%, Air Gas Company) is passed through a moisture / oxygen trap (Chromatography Company). Before ethylene is introduced into the reactor, the residual air in the gas line is purged for three 5-minute cycles. After pressurization, the total pressure is 40 bar. Reactor heating is started, and the reaction time is tracked after reaching a desired temperature of 200°C. After a reaction time of 24 hours, the reactor is cooled in flowing air. Before the remaining head space is exhausted in the fume hood, an aliquot of the gas is taken out from the reactor head space for GC analysis. The remaining solid and liquid were transferred to a fine glass filter (4.0 μm-5.5 μm) and filtered to remove insoluble material by washing with hot (50° C.) CHCl. ​​The soluble hydrocarbons were recovered by evaporating the solvent under reduced pressure (0.1 Torr). Insoluble material, including catalyst and hydrocarbons that were insoluble in hot CHCl, was recovered from the filter. The results for the product formed in Example 8 are shown in Table 2.

[0050] Table 2

[0051] Tested characteristics unit Example 8 Propylene produced mg 11 The produced 2-butene mg 128 Ethane produced mg 13 <![CDATA[CHCl3 soluble product]]> mg 59 <![CDATA[Number average molecular weight (M n )]]> g / mol 2600 <![CDATA[Weight-average molecular weight (M w )]]> g / mol 11000

[0052] Example 9. Catalytic conversion of saturated polyethylene to olefins in a batch reactor at different reaction times

[0053] In Example 9, saturated polyethylene was reacted with ethylene on the first catalyst composition (CC1) and the second catalyst composition (CC2) in a 10 mL batch reactor (Parr reactor, series 2500) according to Table 3. The reaction time was changed. In a N2-filled glove box, the first catalyst composition, the second catalyst composition and the saturated polyethylene were loaded into a Parr 2500 reactor equipped with a pressure gauge and a J-type thermocouple. 28 psi of argon was added as an internal standard. Ethylene (99.999%, Air Gas Company) was passed through a moisture / oxygen trap (Chromatography Company) before use. Before ethylene was introduced into the reactor, the residual air in the gas line was purged for three 5-minute cycles. Reactor heating was started, and the reaction time was tracked after reaching the desired temperature set point of 200°C. After the specified reaction time, the reactor was cooled in flowing air. Before the remaining head space was exhausted in the fume hood, an aliquot of the gas was taken out from the reactor head space for GC analysis. The remaining solid and liquid were transferred to a fine glass filter (4.0 μm-5.5 μm) and filtered to remove insoluble material by washing with hot (50° C.) CHCl. ​​The soluble hydrocarbons were recovered by evaporating the solvent under reduced pressure (0.1 Torr). The insoluble material, including the catalyst and hydrocarbons that were insoluble in the hot CHCl, was recovered from the filter. The results for the products formed in Examples 9A, 9B and 9C are shown in Table 4.

[0054] Table 3

[0055]

[0056] Table 4

[0057] Tested characteristics unit Example 9A Example 9B Example 9C Propylene produced mg 31 11 8 The produced 2-butene mg 26 29 28 Ethane produced mg 7 5 4 <![CDATA[CHCl3 soluble product]]> mg 38 25 8

[0058] Example 10. n-Octadecane over various catalyst compositions in a batch reactor at different reaction times and Catalytic conversion to olefins at reaction temperature

[0059] In Example 10, n-octadecane was reacted with ethylene on two catalyst compositions in a batch reactor (Parr reactor, series 2500) according to Table 5. In a glove box filled with N2, the first catalyst composition (CC 1), the second catalyst composition (CC 2) and n-octadecane were loaded into a 10 mL reactor (Parr 2500) equipped with a pressure gauge and a J-type thermocouple. Ethylene (99.999%, Air Gas Company) was passed through a moisture / oxygen trap (Chromatography Company) before use. Before ethylene was introduced into the reactor, the residual air in the gas line was purged for three 5-minute cycles. Reactor heating was started, and reaction time was tracked after reaching the desired temperature set point. After the specified reaction time, the reactor was cooled in flowing air. An aliquot of gas and liquid was taken out from the reactor head space and gas chromatographic analysis was performed with a flame ionization detector (GC-FID). The results of the products formed in Examples 10A-D and 10E-H are shown in Table 6 and Table 7, respectively.

[0060] Table 5

[0061]

[0062] * In Example 10H ethylene was added in measured mass.

[0063] Table 6

[0064] Tested characteristics unit Example 10A Example 10B Example 10C Example 10D Propylene produced mg 0.35 0.12 0.18 0.27 The produced 2-butene mg 0.24 0.39 0.62 1.1 Ethane produced mg 0 0.04 3.0 4.0

[0065] Table 7

[0066] Tested characteristics unit Example 10E Example 10F Example 10G Example 10H Propylene produced mg 17 4 36 3 The produced 2-butene mg 13 12 16 1.5

[0067] Example 11. Catalytic conversion of saturated polyethylene to olefins in a flow reactor

[0068] In Example 11, a flow reactor was used, such as Figure 1As shown. A 20mL glass reaction sleeve (ID = 19.56mm, OD = 22.15mm) is placed in a 40mL stainless steel stirred tank reactor (ID = 22.16mm, OD = 40mm), and the reactor is placed in an aluminum heating jacket. The temperature of the heating jacket is controlled by a hot plate and a thermocouple (IKA C-MAG HS7 digital). The reactor has two inlets, one for liquid substrates and the second for gaseous substrates. Liquid substrates are delivered to the device using a Hamilton gas-tight syringe (5mL) and a Kd Scientific Legato 100 syringe pump. The gaseous substrate is supplied by a pressurized tank, and its flow rate is set by an Alcat mass flow controller (MCS series). The outlet flows to an Equilibar back pressure regulator, which is used to control the reaction pressure. Attached downstream of the regulator is an Agilent 6850 gas chromatograph (GC). GC is equipped with a 6-port VICI-Valco gas sampling valve. A continuous ethylene flow is used as an internal standard for quantitative olefin formation rate. Stainless steel tubing and fittings were purchased from McMaster-Carr and Swagelok. The GC was equipped with a FID and a Petrocol DH capillary GC column (100 mm×0.25 mm×0.5 μm film thickness). The column was maintained at 45 PSI and the gas sample was split at 50:1. The column conditions and product elution times are shown in Tables 8 and 9, respectively.

[0069] Table 8

[0070] Oven slope ℃ / min Next ℃ Keep min initial 50 8 Ramp1 15 100 1 Ramp2 15 150 15.00

[0071] Table 9

[0072] Hydrocarbon substances Elution time min Ethylene 8.2 Propylene 8.3 Butene 8.8–9.0 Pentene 10.1–9.5 Hexene 12.2–14.1 Heptene 15.1–17.0 Octene 19.0–20.1 Nonene 22.0–24.1 Decene 25.4–26.3

[0073] In the glove box filled with Ar, 249mg of saturated polyethylene, 146mg of Example 1 and 36.6mg of Example 7 were loaded into the stirred tank reactor. After loading, the reactor was taken out from the glove box, placed in an aluminum heating jacket, and connected to an ethylene delivery source. The Ar atmosphere in the reactor was evacuated for at least 15 minutes using a continuous ethylene stream fed with 5mL / min. Within 19.5 hours, ethylene gas (10.1mL / min) was continuously flowed into the reactor heated to and maintained at 130°C and 1atm. In order to monitor the reaction progress, for the reaction duration of 19.5 hours, a sample (0.25mL) of the gas effluent was analyzed via GC every 34.2 minutes. The results of Example 11 are shown in Table 10. The maximum propylene formation rate (R) detected when measuring the catalyst operation was 1.5 wt. % and 1.5 wt. % respectively. C3,max ), the unit is millimole / hour (mmol h-1 ). Measure the maximum propylene selectivity (S C3 The propylene formation rate is normalized by the cumulative olefin formation rate for a given reaction time. The average propylene selectivity (S C3,avg ) and the average butene selectivity (S C4,avg ) is evaluated at each sampling point during the continuous reaction process of each substance. The polyethylene conversion rate (in weight percent) is also calculated by calculating the mass of polyethylene consumed per olefin produced according to Formula 1:

[0074]

[0075] Where i represents the number of carbon units in the olefin, MW i represents the molecular weight of substance "i", n ci - is the number of moles of substance "i" formed during the experiment, and m PE,o - is the initial loading of polyethylene, assuming that each olefin molecule formed contains two carbons from ethylene.

[0076] Table 10

[0077] Olefins detected <![CDATA[R C3,max / mmol h -1 ]]> <![CDATA[S C3,max ]]> <![CDATA[S C3,avg ]]> <![CDATA[S C4,avg ]]> PE conversion rate <![CDATA[C3-C4]]> 0.04 0.83 0.72 0.28 1.2 wt%

[0078] It should be noted that one or more of the following claims utilize the term "where" or "in which" as a transitional phrase. For purposes of defining the present technology, it should be noted that this term is introduced in the claims as an open transitional phrase that is used to introduce a recitation of a series of characteristics of a structure and should be interpreted in a manner similar to the more commonly used open preamble term "comprising". For purposes of defining the present technology, the transitional phrase "consisting of" may be introduced in a claim as a closed preamble term that limits the scope of the claim to the listed components or steps and any naturally occurring impurities. For purposes of defining the present technology, the transitional phrase "consisting essentially of" may be introduced in a claim to limit the scope of one or more claim items to the stated elements, components, materials, or method steps and any non-stated elements, components, materials, or method steps that do not materially affect the novel characteristics of the claimed subject matter. The transition phrases "consisting of" and "consisting essentially of" may be interpreted as a subset of open transition phrases, such as "comprising" and "including", such that any use of an open phrase to introduce a statement of a list of elements, components, materials, or steps should be interpreted as also disclosing the statement of the list of elements, components, materials, or steps using the closed terms "consisting of" and "consisting essentially of". For example, a statement that a composition "comprising" components A, B, and C should be interpreted as also disclosing a composition "consisting of" components A, B, and C as well as a composition "consisting essentially of" components A, B, and C. Any quantitative value expressed in this application may be considered to include open embodiments that conform to the transition phrases "comprising" or "comprising" as well as closed or partially closed embodiments that conform to the transition phrases "consisting of" and "consisting essentially of".

[0079] As used in the specification and the appended claims, the singular forms "a", "an", and "the" include plural references unless the context clearly indicates otherwise. The verb "comprise" and its cognate forms should be interpreted as referring to elements, components, or steps in a non-exclusive manner. The referenced elements, components, or steps may exist, be utilized, or be combined with other elements, components, or steps that are not explicitly referenced.

[0080] It should be understood that any two quantitative values ​​assigned to a characteristic may constitute the range of the characteristic, and all combinations of ranges formed by all said quantitative values ​​of a given characteristic are considered in the present disclosure. The subject matter of the present disclosure has been described in detail and by reference to specific embodiments. It should be understood that any detailed description of a component or feature of one or more embodiments does not necessarily imply that a component or feature is necessary for a particular embodiment or any other embodiment. Further, it will be apparent to those skilled in the art that various modifications and changes may be made to the described embodiments without departing from the essence and scope of the claimed subject matter.

Claims

1. A method for converting saturated polyethylene into at least one m H 2m A method for producing an olefin product, the method comprising contacting the saturated polyethylene with three or more catalyst components in a reactor, the reactor comprising a chemical formula C n H 2n of an olefin reactant; in: m is an integer from 3 to 20; n is an integer from 2 to 20; The three or more catalyst components include a metathesis catalyst component, an isomerization catalyst component, and a dehydrogenation catalyst component; and The contacting causes at least a portion of the saturated polyethylene to undergo a dehydrogenation reaction to form an unsaturated polyethylene, and at least a portion of the unsaturated polyethylene or a product derived therefrom to undergo a metathesis reaction and an isomerization reaction to produce at least a m H 2m of the olefin product effluent.

2. The process of any one of the preceding claims, wherein the pressure of the olefin reactant in the reactor during the contacting is from 0 pounds per square inch gauge (psig) to 3000 psig.

3. The process according to any one of the preceding claims, wherein the temperature of the reactor during the contacting is less than or equal to 400°C.

4. The process of any one of the preceding claims, wherein the olefin reactant comprises ethylene, propylene, butenes, pentenes, or combinations thereof.

5. The process of any one of the preceding claims, wherein the olefin product comprises propylene, butenes, pentenes, or combinations thereof.

6. The process according to any one of the preceding claims, wherein the metathesis catalyst component comprises an element selected from International Union of Pure and Applied Chemistry (IUPAC) Groups 5-10.

7. The process of any one of the preceding claims, wherein the metathesis catalyst component comprises rhenium, ruthenium, tungsten, molybdenum, vanadium, or a combination thereof.

8. The process according to any one of the preceding claims, wherein the metathesis catalyst component comprises methyltrioxorhenium (MTO).

9. The process according to any one of the preceding claims, wherein the isomerization catalyst component comprises an element selected from IUPAC Groups 5-10.

10. The process of any one of the preceding claims, wherein the isomerization catalyst component comprises alumina, silica, iridium, palladium, ruthenium, or combinations thereof.

11. The process according to any one of the preceding claims, wherein the dehydrogenation catalyst component comprises an element selected from IUPAC Groups 5-10.

12. The process of any one of the preceding claims, wherein the dehydrogenation catalyst component comprises platinum, iridium, ruthenium, rhenium, or a combination thereof.

13. The process of any one of the preceding claims, wherein a first catalyst composition comprises the metathesis catalyst component and the isomerization catalyst component, and wherein the first catalyst composition comprises MTO on alumina.

14. The method according to any one of the preceding claims, wherein the second catalytic composition comprises the isomerization catalytic component and the dehydrogenation catalytic component, and wherein the second catalytic composition comprises platinum on alumina, platinum on silica, [tert-butyl-POCOP]Ir[C2H4], or a combination thereof.

15. The process of any one of the preceding claims, wherein a first catalyst composition comprising MTO on alumina and a second catalyst composition comprising platinum on alumina contact the saturated polyethylene in the reactor.

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