Patent Application
20240336713
Method and system embodiments for converting feedstocks comprising mixture of light olefins into jet-range olefins via co-oligomerization using hybrid catalyst system embodiments are disclosed.
Despite recent development of effective heterogeneous approaches to ethylene conversion, currently there exists a significant technological gap concerning the co-oligomerization of ethylene with C3+ olefins and a catalytic approach that can effectively co-oligomerize mixed olefins to form jet-range olefins in high yield. A need exists in the art for a method that can be used to arrive at products that can be used to provide jet fuel hydrocarbons with high yield and selectivity.
Disclosed herein are embodiments of a method, comprising: contacting, in a single reactor, a feedstock comprising a mixture of C2 and C3+ olefins with a hybrid catalyst system comprising a transition-metal based catalyst and an acid catalyst, and heating the single reactor at a temperature, such as at a temperature ranging from 250° C. to 500° C., to convert the feedstock into an oligomerized product composition comprising jet-range olefins via co-oligomerization.
Also disclosed herein are embodiments of a reactor for performing the method as described herein, where the reactor comprising a hybrid catalyst system comprising a transition-metal based catalyst and an acid catalyst, wherein the transition-metal based catalyst and the acid catalyst are provided on separate catalyst beds or on the same catalyst bed and the hybrid catalyst system is provided in an amount sufficient to convert C2 and C3+ olefins into jet-range olefins via co-oligomerization.
Also disclosed herein are embodiments of a combination comprising a feedstock comprising a mixture of C2 and C3+ olefins, and a hybrid catalyst system comprising a transition-metal based catalyst and an acid catalyst.
Also disclosed herein are embodiments of a method, comprising contacting, in a single reactor, a feedstock comprising a mixture of C2 and C4 olefins with a single catalyst component comprising a transition-metal based catalyst and an acid catalyst, and heating the single reactor at a temperature ranging from 150° C. to 300° C. to convert the feedstock into an oligomerized product composition comprising jet-range and/or diesel-range olefins via co-oligomerization.
The foregoing and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
The following explanations of terms and abbreviations are provided to better describe the present disclosure and to guide those of ordinary skill in the art in the practice of the present disclosure. As used herein, “comprising” means “including” and the singular forms “a” or “an” or “the” include plural references unless the context clearly dictates otherwise. The term “or” refers to a single element of stated alternative elements or a combination of two or more elements, unless the context clearly indicates otherwise.
Unless explained otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present disclosure, suitable methods and materials are described below. The materials, methods, and examples are illustrative only and not intended to be limiting. Other features of the disclosure are apparent from the following detailed description and the claims.
The disclosure of numerical ranges should be understood as referring to each discrete point within the range, inclusive of endpoints, unless otherwise noted. Unless otherwise indicated, all numbers expressing quantities of components, molecular weights, percentages, temperatures, times, and so forth, as used in the specification or claims are to be understood as being modified by the term “about.” Accordingly, unless otherwise implicitly or explicitly indicated, or unless the context is properly understood by a person of ordinary skill in the art to have a more definitive construction, the numerical parameters set forth are approximations that may depend on the desired properties sought and/or limits of detection under standard test conditions/methods as known to those of ordinary skill in the art. When directly and explicitly distinguishing embodiments from discussed prior art, the embodiment numbers are not approximates unless the word “about” is recited.
Also, the following description is exemplary in nature and is not intended to limit the scope, applicability, or configuration of the present disclosure. Various changes to the described embodiment may be made in the function and arrangement of the elements described herein without departing from the scope of the preset disclosure. Further, descriptions and disclosures provided in association with one particular embodiment are not limited to that embodiment and may be applied to any embodiment disclosed. Further, the terms “coupled” and “associated” generally mean fluidly, electrically, and/or physically (e.g., mechanically or chemically) coupled or linked and does not exclude the presence of intermediate elements between the coupled or associated items absent specific contrary language.
Although the operations of exemplary embodiments of the disclosed method and/or system embodiments may be described in a particular, sequential order for convenient presentation, it should be understood that disclosed embodiments can encompass an order of operations other than the particular, sequential order disclosed, unless the context dictates otherwise. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Further, descriptions and disclosures provided in association with one particular embodiment are not limited to that embodiment and may be applied to any disclosed embodiment.
To facilitate review of the various embodiments of the disclosure, the following explanations of specific terms are provided.
Co-oligomerization: A chemical process that oligomerizes a feedstock comprising a mixture of (i) C2 olefins and (ii) C3+ olefins. In particular embodiments, the co-oligomerization takes place in a single reactor using a hybrid catalyst system that can be provided on a single catalyst bed or a dual catalyst bed.
Diesel-Range Olefins: A component of an oligomerized product mixture according to the present disclosure that comprises one or more olefins having at least 11 carbon atoms and typically up to 23 carbon atoms.
Hybrid catalyst system: A catalyst system having at least two different catalysts. In some embodiments, the hybrid catalyst system can comprise a physical mixture of the at least two different catalysts. In other embodiments, the hybrid catalyst system can comprise the at least two different catalysts as physically separate components. The hybrid catalyst system typically comprises a first catalyst that is a transition metal-based catalyst and a second catalyst that is an acid catalyst.
Jet fuel: A hydrocarbon or hydrocarbon mixture that distills at a temperature ranging from 120° C. to 300° C. In some embodiments, these types of hydrocarbons can include those with a carbon number between C8 and C16; however, actual range limits for commercial use can depend on other required fuel properties.
Jet-Range Olefins: A component of an oligomerized product mixture according to the present disclosure that comprises one or more olefins having at least eight carbon atoms and typically up to 16 carbon atoms.
Mobil-type five (MFI) zeolites: Zeolites with structure type “MFI,” which are three dimensional microporous aluminosilicates with pore openings of 5.5 Å.
Non-jet-range product: A hydrocarbon or hydrocarbon mixture comprising at least some olefins that can be generated by the co-oligomerization process according to the present disclosure, along with the jet-range olefins. In some embodiments, non-jet-range products can include olefins having carbon numbers less than 8.
Olefin/Alkene: An unsaturated hydrocarbon containing at least one double bond positioned along the length of the hydrocarbon chain. The hydrocarbon chain may be straight (i.e., acyclic, linear, or normal), cyclic, or branched (e.g., containing one or more hydrocarbon sidechains). As used herein, “C2 olefin” refers to an olefin having two carbon atoms (also referred to herein as “ethylene”); “C3+ olefins” refers to a mixture of olefins, wherein each olefin has at least three carbon atoms.
Oligomerization: A chemical process that converts lower olefins to higher carbon-number olefins that can be used as fuels, such as aviation fuel, via chemical reaction(s).
Single-pass conversion: A yield of product obtained after one pass through a system/oligomerization method according to the present disclosure. The yield is calculated as: difference between the C2 and C3 olefins in reactor feed and the C2 and C3 olefins in reactor outlet, divided by the C2 and C3 olefins in reactor feed.
Syngas or Synthesis Gas: A fuel gas mixture typically made up of hydrogen, carbon monoxide, and, optionally, carbon dioxide.
Transition Metal-Based Catalyst: A catalyst comprising a metal component and a support component. The support component of any transition metal-based catalyst may be similar in chemical make-up as a solid acid catalyst as described herein; however, the support component of the transition metal-based catalyst is a separate component than the acid catalyst component of any hybrid catalyst system.
ZSM-5 or ZSM-5 zeolites: ZSM-5 (which stands for Zeolite Socony Mobil-five) is an aluminosilicate zeolite containing a three-dimensional channel system. The chemical formula of ZSM-5 is NanAlnSi96−nO192·16H2O (wherein 0<n<27). The typical pore size is 5.5 Å.
Disclosed herein are embodiments of a method for converting a feedstock comprising a mixture of C2 and C3+ olefins into jet-range olefins via co-oligomerization using a hybrid catalyst system, as well as embodiments of a system for carrying out such method embodiments. In particular embodiments, the method uses a single reactor to convert C2 and C3+ olefins to jet-range products.
Also disclosed here are embodiments of a method for converting a feedstock comprising a mixture of C2 and C4 olefins into jet-range and/or diesel-range olefins via co-oligomerization using a single catalyst component, as well as embodiments of a system for carrying out such method embodiments. In particular embodiments, the method is able to produce jet-range olefins in a selective single-step oligomerization.
To meet the immediate need for decarbonization of the aviation industry, leveraging existing commercial processes and feedstocks will be the most efficient path toward producing SAF in the near-term future. Syngas is one of the most attractive feed sources as it can be derived from a broad range of renewable and waste feedstocks via gasification, while benefiting from existing infrastructure throughout the petrochemical industry. This general applicability makes syngas an effective vehicle for accessing a wide range of renewable feedstocks where heterogeneity precludes the use of conventional conversion pathways. These include ecologically disadvantaged feedstocks such as municipal solid wastes (MSW) and residual biomass that can offer significant carbon reductions.
Of the existing industrial processes for transforming syngas to synthetic fuels, none produce aviation fuel efficiently. Several industrial syngas-based technologies have been developed to produce synthetic fuels, based on either direct conversion through the Fischer-Tropsch (FT) chemistry or indirect conversion via the synthesis of a methanol intermediate. Commercial FT processes, which include the Shell Middle Distillate Synthesis (SMDS) and Conversion to Distillates (COD) developed by PetroSA, typically involve high capital costs due to complex reactor design and require additional unit operations to upgrade wax byproducts. Methanol-based technologies include Mobil's Methanol-to-Gasoline (MTG) and Mobil-Olefins-to-Gasoline- and-Distillate (MOGD) processes. The MTG process is limited to the production of ≤C10 hydrocarbons and effluent streams typically contain substantial amounts of aromatics. Modification of MTG operating conditions and unit operations results in the MOGD process, which allows for the production of diesel-range hydrocarbons at higher costs but still generates a significant fraction of unwanted gasoline-range aromatics. Overall, these commercialized processes offer little market penetration, and none of them provide a high selectivity to jet-range products despite their operational complexity.
Table 1 provides a comparison of yields obtained using syngas-based conversion technology currently existing in the art to generate SAF and an exemplary yield obtained using a method embodiment according to the present disclosure.
Methanol synthesis followed by methanol-to-olefin (MTO) processing offers an already established and active commercialized pathway to produce mixed light olefins, primarily ethylene and propylene. This mixture of light olefins can potentially be directly oligomerized to jet-range products in a single reaction step; however, the difference in reactivity and corresponding oligomerization pathways between C2 and C3+ olefins make this challenging, particularly in view of the well-known difficulty of converting ethylene, which exhibits a relatively high stability compared to other olefins.
Generating mixed olefin mixtures with average carbon numbers of 3 to 4, possible from a number of different pathways such as MTO, opens the possibility for a significant reduction in process complexity such as using single-step oligomerization approach to generating jet-range products that can be converted to jet fuel. Such an approach will require a correspondingly high conversion of the ethylene fraction in the same reaction step.
A significant technological gap regarding the co-oligomerization of ethylene with C3+ olefins exists in the art. The present disclosure, however, describes method embodiments that facilitate making jet-range products that can be converted to jet fuel, wherein the method uses feedstocks comprising C2 and C3+ olefin mixtures. In particular embodiments, a hybrid catalyst system is used and maintains the overall improvement in process intensity while still allowing for independent optimization of the Cossee-Arlman and acid-catalyzed reactions.
Embodiments of a method for converting feedstocks into an oligomerized product composition via co-oligomerization are disclosed. The oligomerized product composition comprises jet-range olefins that can be converted to jet fuel. In some embodiments, the method includes contacting a feedstock with a novel hybrid catalyst system to convert the feedstock into the oligomerized product composition via co-oligomerization in a single reactor comprising (i) a single catalyst bed system comprising a hybrid catalyst system (e.g., wherein components of the hybrid catalyst system are mixed within/on a single catalyst bed); or (ii) a dual catalyst bed system comprising the hybrid catalyst system (e.g., wherein components of the hybrid catalyst system are placed within/on separate catalyst beds in sequential order). In some other embodiments, the method includes contacting a feedstock with a single catalyst component to convert the feedstock into the oligomerized product composition via co-oligomerization in a single reactor comprising a single catalyst bed system comprising the single catalyst component.
Other aspects of the disclosed method and system embodiments are described herein.
In some embodiments, the feedstock comprises mixed olefins. In certain embodiments, the mixed olefins include a mixture of C2 and C3+ olefins. C3+ olefins can comprise C3 olefins, C4 olefins, C5 olefins, C6 olefins, Ce olefins, and any combinations thereof.
In some embodiments, the mixture of C2 and C3+ olefins includes C2 to C5 olefins. In one embodiment, the mixture of C2 and C3+ olefins comprises C2 and C4 olefins. In another embodiment, the mixture of C2 and C3+ olefins consists essentially of C2 and C4 olefins. In yet another embodiment, the mixture of C2 and C3+ olefins consists of C2 and C4 olefins.
In some embodiments, the C3+ olefins comprise olefins with carbon numbers of 3 or higher. In certain embodiments, the C3+ olefins comprise olefins with carbon numbers ranging from 3 to 7. In one embodiment, the C3+ olefins comprise a mixture of at least C3, C4, and C5 olefins. In another embodiment, the C3+ olefins comprise a majority of C4 olefins. In a particular embodiment, the C3+ olefins consist essentially of C4 olefins.
In some embodiments, the mixed olefins comprise C2 and C4 olefins in mole ratio of from 1:9 to 1:1. In some embodiments, the feedstock comprises a mixture of C2 and C4 olefins wherein the C4 olefins are present in an amount ranging from 5 vol % to 70 vol %. In certain embodiments, the feedstock comprises a mixture of C2 and C4 olefins wherein the C4 olefins are present in an amount ranging from 60 vol % to 65 vol %. In one particular embodiment, the feedstock comprises a mixture of C2 and C4 olefins wherein the C4 olefins are present in an amount of 63 vol %.
In particular embodiments, the feedstock comprising a mixture of C2 and C3+ olefins is derived from a carbonaceous feed source. In one embodiment, the carbonaceous feed source includes coal. In some other embodiments, the carbonaceous feed source includes a heterogeneous carbonaceous feed source. Advantageously, in certain embodiments, the heterogeneous carbonaceous feed source includes ecologically disadvantaged sources such as municipal solid wastes (MSW) and residual biomass that can offer significant carbon reductions. In other embodiments, the heterogeneous carbonaceous feed source includes industrial off-gas and biogas.
In any of the foregoing or following embodiments, the feedstock comprising a mixture of C2 and C3+ olefins is derived from a feed source via a feedstock pathway.
In one embodiment, the feedstock comprising a mixture of C2 and C3+ olefins is derived from a feed source comprising biomass or waste (e.g., municipal solid waste, industrial off-gas, biogas, and the like) via dehydration of small-oxygenates produced through fermentation. In another embodiment, the feedstock comprising a mixture of C2 and C3+ olefins is derived from a feed source comprising biomass via cracking naphtha streams from fractionation of biofuels produced from processes such as catalytic fast pyrolysis. In yet another embodiment, the feedstock comprising a mixture of C2 and C3+ olefins is derived from a feed source comprising waste via hydrotreating the waste.
In some embodiments, the feedstock comprises mixed olefins with a C3+:C2 molar ratio ranging from 9:1 to 1:9, such as from 8:1 to 1:8, or from 7:1 to 1:7, or from 6:1 to 1:6, or from 5:1 to 1:5, or from 4:1 to 1:4, or from 3:1 to 1:3, or from 2:1 to 1:2. In certain embodiments, the feedstock comprises mixed olefins with a C3+:C2 molar ratio ranging from 3:1 to 1:1. In some other embodiments, the feedstock comprises mixed olefins with a C3+:C2 molar ratio ranging from 2:1 to 1:2. In one embodiment, the feedstock comprises mixed olefins with a C3+:C2 molar ratio of 2:1. In another embodiment, the feedstock comprises mixed olefins with a C3+:C2 molar ratio of 3:1. In yet another embodiment, the feedstock comprises mixed olefins with a C3+:C2 molar ratio of 5:1.
In some other embodiments, the feedstock comprises mixed olefins with a C3+:C2 molar ratio ranging from 5:1 to 1:5, wherein the C3+ olefins comprises C3, C4 and C5 olefins. In certain embodiments, the feedstock comprises mixed olefins with a C3+:C2 molar ratio ranging from 3:1 to 1:3. In some other embodiments, the feedstock comprises mixed olefins with a C3+:C2 molar ratio ranging from 2:1 to 1:2. In one embodiment, the feedstock comprises mixed olefins with a C3+:C2 molar ratio of 2:1. In another embodiment, the feedstock comprises mixed olefins with a C3+:C2 molar ratio of 3:1. In yet another embodiment, the feedstock comprises mixed olefins with a C3+:C2 molar ratio of 5:1.
In some other embodiments, the feedstock comprises mixed olefins with a C3+:C2 (e.g., C3:C2, C3+:C2, or C4:C2) molar ratio ranging from 4:1 to 1:4. In certain embodiments, the feedstock comprises mixed olefins with a C3+:C2 (e.g., C3:C2, C3+:C2, or C4:C2) molar ratio ranging from 3:1 to 1:1. In some other embodiments, the feedstock comprises mixed olefins with a C3+:C2 (e.g., C3:C2, C3+:C2, or C4:C2) molar ratio ranging from 2:1 to 1:2. In one embodiment, the feedstock comprises mixed olefins with a C3+:C2 (e.g., C3:C2, C3+:C2, or C4:C2) molar ratio of 2:1.
In some embodiments, the feedstock comprises mixed olefins with a C2:C3:C4:C5 molar ratio of 2:2:1:1. In some other embodiments, the feedstock comprises mixed olefins with a C2:C3:C4:C5 molar ratio of 1:1:1:1. In some other embodiments, the feedstock comprises mixed olefins with a C2:C3:C4:C5 molar ratio of 1:1:2:2.
In particular embodiments, the feedstock comprising a mixture of C2 and C3+ olefins is derived from a feed source comprising syngas via a methanol-to-olefin based (MTO) pathway comprising methanol synthesis followed by an MTO process.
In some embodiments, a carbonaceous feed source is gasified into syngas. In further embodiments, the syngas is reacted over a catalyst at a reaction temperature under a reaction pressure to produce methanol. The catalyst may comprise a Cu catalyst, ZnO catalyst, or Al2O3 catalyst. In some embodiments, the reaction temperature ranges from 200° C. to 300° C., such as 230° C. to 275° C. or 250° C. to 270° C. In some embodiments, the reaction pressure ranges from 40 bar to 70 bar, such as 50 bar to 60 bar, or 55 bar to 60 bar. In some embodiments, the methanol selectivity is greater than 90%, such as greater than 95%, or greater than 99%.
In some embodiments, the methanol to olefin process comprises react methanol with a catalyst at a reaction temperature under a reaction pressure to produce olefins. In certain embodiments, the catalyst is a SAPO-34 catalyst. In some embodiments, the reaction temperature ranges from 400° C. to 500° C., such as from 430° C. to 470° C., or 450° C. to 470° C. In some embodiments, the reaction pressure ranges from 40 bar to 70 bar, such as 50 bar to 60 bar, or 55 bar to 60 bar. In some embodiments, the olefins comprise small olefins. In certain embodiments, the olefins comprise ethylene and propylene. In one embodiment, the selectivity of ethylene and propylene to total olefins is greater than 80%, such as greater than 90%, or greater than 92%.
Embodiments of a method for converting feedstocks into an oligomerized product composition via co-oligomerization are disclosed. The oligomerized product composition is suitable for conversion to jet fuel.
In some embodiments, the method comprises contacting, in a single reactor, a feedstock with a single catalyst component and heating the single reactor to convert the feedstock into an oligomerized product composition comprising jet-range olefins (and, in some embodiments, diesel-range olefins) via co-oligomerization.
In some other embodiments, the method comprises contacting, in a single reactor, a feedstock with a hybrid catalyst system and heating the single reactor to convert the feedstock into an oligomerized product composition comprising jet-range olefins via co-oligomerization.
In some embodiments, the oligomerized product composition further comprises non-jet-range products, such as non-jet-range olefins. In certain embodiments, the non-jet-range products comprise olefins having carbon numbers below C8. In certain embodiments, non-jet-range products include C2-C7 olefins. In other embodiments, the non-jet-range products include C3+ olefins. In one embodiment, the non-jet-range products include C3-C7 olefins.
In some embodiments, the single reactor is operated or heated at a temperature ranging from 100° C. to 500° C., such as 100° C. to 450° C., 150° C. to 400° C., 150° C. to 300° C., 150° C. to 500° C., 250° C. to 500° C., 200° C. to 350° C., and 250° C. to 300° C. In certain embodiments, the single reactor is operated at a temperature ranging from 200° C. to 300° C. or 250° C. In yet other embodiments, the single reactor is operated at a temperature ranging from 250° C. to 500° C., such as 250° C. to 450° C., 250° C. to 400° C., or 250° C. to 350° C.
In some embodiments, the olefins are oligomerized under a pressure ranging from 50 psig to 500 psig, such as 50 psig to 450 psig, or 55 psig to 400 psig, or 60 psig to 400 psig, or 70 psig to 350 psig, or 75 psig to 350 psig, or 75 psig to 300 psig, or 75 psig to 200 psig, or 75 psig to 150 psig, or 75 psig to 125 psig. In some embodiments, the pressure can range from 200 psig to 500 psig. In certain embodiments, the olefins are oligomerized under a pressure ranging from 75 to 500 psig, such as from 75 to 300 psig, or 75 psig to 200 psig. In one embodiment, the pressure is 100 psig. In another embodiment, the pressure is 200 psig.
In some embodiments, contacting the feedstock with the hybrid catalyst system comprises contacting the feedstock with a first catalyst bed comprising the transition-metal based catalyst to produce a first product mixture and then contacting the first product mixture with a second catalyst bed comprising the acid catalyst to convert the first product mixture into the oligomerized product composition. In such embodiments, the first catalyst bed and second catalyst bed are contained in the single reactor.
In further embodiments, the method further comprises separating the jet-range olefins from any non-jet-range products; and/or contacting the non-jet-range products with the hybrid catalyst system to produce jet-range olefins.
In other embodiments, the method comprises contacting (or exposing), in a single reactor, a feedstock comprising a mixture of C2 and C3+ olefins with (or to) the hybrid catalyst system and heating the single reactor to convert the feedstock into an oligomerized product composition comprising jet-range olefins and non-jet-range olefins via co-oligomerization, separating the jet-range olefins from the non-jet-range products, and recycling the non-jet-range products for further oligomerization. In certain embodiments, recycling the non-jet-range products comprises contacting the non-jet-range products with the hybrid catalyst system to produce jet-range olefins.
In some embodiments, the hybrid catalyst system comprises a mixed bed configuration wherein both components of the hybrid catalyst system are contained on a single catalyst bed. In some other embodiments, the hybrid catalyst system comprises a staged bed configuration wherein the two components of the hybrid catalyst system are contained on separate catalyst beds. In some embodiments, the hybrid catalyst system is configured to comprise a catalyst bed comprising Ni/SiO2—Al2O3 catalyst and a zeolite catalyst. In such embodiments, the Ni/SiO2—Al2O3 catalyst is loaded on a catalyst bed positioned near the top of the reactor, and the zeolite catalyst is loaded on a catalyst bed positioned near the bottom of the reactor.
In some embodiments, the disclosed method produces a product stream comprising the oligomerized product composition. In certain embodiments, the oligomerized product composition comprises n- and/or iso-alkenes. In one embodiment, the oligomerized product composition consists essentially of n- and/or iso-alkenes. In another embodiment, the oligomerized product composition consists of n- and/or iso-alkenes. In some implementations, the oligomerized product composition comprises 0 wt % to less than 10 wt % aromatics, such as 0 wt % to less than 5 wt % aromatics. In certain implementations, the oligomerized product composition comprises 0 wt % to less than 3 wt % aromatics. In some embodiments, aromatic hydrocarbons may be formed at a concentration below 4 wt %. In an exemplary implementation, the oligomerized product composition comprises no traces of aromatics.
In some embodiments, the method further comprises hydrogenating the jet-range olefins made according to the described method to produce saturated hydrocarbons suitable for jet fuel.
The disclosed embodiments of process variations offer flexibility to adapt feed variability and are dependent on the efficacy of the core C2+ co-oligomerization technology. In some embodiments, more efficient co-oligomerization will lower the need for larger recycle loops and make single-pass processes more viable.
In some embodiments, the hybrid catalyst system comprises a transition metal-based catalyst and an acid catalyst. A single catalyst component according to the present disclosure can also be a transition metal-based catalyst but does not comprise a separate acid catalyst component.
The transition metal-based catalyst can be a catalyst capable of catalyzing a Cossee-Arlman mechanism of oligomerization. In exemplary embodiments, the transition metal-based catalyst facilitates oligomerizing C2 olefins present in the feedstock.
In particular embodiments, the transition metal-based catalyst and the single catalyst component, independently, comprise a metal component embedded on a solid support. In certain embodiments, the transition metal-based catalyst and the single catalyst component, independently, comprise nickel (Ni), platinum (Pt), rhodium (Rh), palladium (Pd), or other transition metals, including any combinations and/or alloys thereof. In certain embodiments, the transition metal-based catalyst and the single catalyst component, independently, are a transition metal-loaded aluminosilicate. In some applications, the transition metal-based catalyst and the single catalyst component, independently, are a nickel-loaded aluminosilicate catalyst. In some embodiments, the solid support is silica alumina. In certain embodiments, the solid support is large pore zeolite. In one embodiment, the solid support is amorphous silica alumina.
In some embodiments, the transition metal-based catalyst and the single catalyst component, independently, are obtained via embedding a transition metal on a solid support. In one embodiment, the transition metal-based catalyst is derived by exchanging Ni2+ ions onto alumina-silicates to provide Ni-SiAl. The nickel introduction for the transition metal-based catalyst and/or the single catalyst component may be achieved by wetness impregnation, incipient wetness impregnation, or ion exchange. In some embodiments, the transition metal-based catalyst comprises Ni/SiO2—Al2O3. In some embodiments, the single catalyst component comprises a Ni-embedded support wherein the support is selected from a BEA zeolite, a HY zeolite, a MOR zeolite, SiO2—Al2O3, or MCM-41.
The acid catalyst of the hybrid catalyst system can be a catalyst capable of catalyzing Brønsted acid (BA) catalyzed oligomerization. In exemplary embodiments, the acid catalyst facilitates oligomerizing C3+ olefins to generate C8+ olefins through BA-catalyzed oligomerization. In some embodiments, C3+ olefins are oligomerized through the acid catalyst to generate C6-C18 olefins.
In some embodiments, the acid catalysts of the hybrid catalyst component and/or the support of the single catalyst component can comprise significant Brønsted acid (BA) sites. In some embodiments, the acid catalyst of the hybrid catalyst component and/or the support of the single catalyst component comprises MFI zeolites. In certain embodiments, the acid catalyst of the hybrid catalyst component and/or the support of the single catalyst component comprises MFI zeolites with a Si/Al ratio ranging from 10 to 300, such as from 10 to 290, 10 to 250, 30 to 200, 30 to 280, 40 to 150, 50 to 100, 30 to 80, 60 to 90, or 70 to 90. In one embodiment, the acid catalyst of the hybrid catalyst component and/or the support of the single catalyst component comprises MFI zeolites with a Si/Al ratio ranging from 70 to 90. In another embodiment, the acid catalyst of the hybrid catalyst component and/or the support of the single catalyst component comprises MFI zeolites with a Si/Al ratio of 80.
In some embodiments, the MFI zeolite is ZSM-5 zeolite. In some embodiments, the ZSM-5 zeolite is selected from a zeolite sold by Zeolyst, such as CBV 3014, CBV 5524, CBV 8014 and CBV 28014. In another embodiment, the ZSM-5 zeolite is CBV 8014. In certain embodiment, the acid catalyst comprises a BEA zeolite catalyst.
In some embodiments, the hybrid catalyst system comprises a Ni-based catalyst that also promotes BA sites. In certain embodiments, the hybrid catalyst system comprises a Ni-SiAl catalyst and a separate MFI zeolite catalyst. In one embodiment, the hybrid catalyst system comprises Ni/SiO2—Al2O3 and MFI zeolites with a Si/Al ratio ranging from 10 to 300, such as from 10 to 250, from 30 to 200, from 40 to 150, from 50 to 100, from 60 to 90, and from 70 to 90. In another embodiment, the hybrid catalyst system comprises Ni/SiO2—Al2O3 and MFI zeolites with a Si/Al ratio of 80.
In some other embodiments, the single catalyst component comprises a metal selected from Ni, Cu, or Ag that is embedded on a support selected from a BEA zeolite, a HY zeolite, SiO2—Al2O3, a MOR zeolite, or MCM-41. In some embodiments, the metal is present in an amount ranging from 0.5 wt. % to 10 wt. %, such as 0.5 wt. % to 7 wt. %, or 0.5 wt. % to 1 wt. %. In particular such embodiments, the metal is Ni, and the support is a BEA zeolite. In certain representative embodiments, the metal is Ni, and the Ni is present in an amount of 2 wt. % or 5 wt. %.
The disclosed method provides an oligomerized product composition that comprises jet-range olefins. In some embodiments, the jet-range olefins comprise olefins having carbon numbers ranging from C6 to C16. In certain embodiments, the jet-range olefins comprise C8 to C16 olefins. In one embodiment, the jet-range olefins comprise C8 to C15 olefins. In another embodiment, the jet-range olefins comprise C10 to C15 olefins. In yet another embodiment, the jet-range olefins comprise C10 to C13 olefins.
The oligomerized product composition may further comprise non-jet-range products. In some embodiments, a ratio of the jet-range olefins to the non-jet-range products may be at least 25%.
In some embodiments using the single catalyst component, the ratio of the jet-range olefins to the non-jet-range products ranges from 25% to 90%. In certain embodiments, the ratio of the jet-range olefins to the non-jet-range products ranges from 30% to 70%. In some other embodiments, the ratio of the jet-range olefins to the non-jet-range products ranges from 70% to 85%. In one embodiment, the ratio of the jet-range olefins to the non-jet-range products is at least 30%. In another embodiment, the ratio of the jet-range olefins to the non-jet-range products is 30%. In yet another embodiment, the ratio of the jet-range olefins to the non-jet-range products is 50%.
In some other embodiments, using the hybrid catalyst component, the ratio of the jet-range olefins to the non-jet-range products is at least 30%, such as at least 40%, at least 50%, at least 60%, or at least 65%. In further embodiments, the ratio of the jet-range olefins to the non-jet-range products is at least 70%. In one embodiment, the ratio of the jet-range olefins to the non-jet-range products is at least 75%. In another embodiment, the ratio of the jet-range olefins to the non-jet-range products is at least 80%.
In some other embodiments, using the hybrid catalyst component, the ratio of the jet-range olefins to the non-jet-range products ranges from 70% to 85%.
In some embodiments, at least 40% of the mixture of C2 and C3+ olefins is converted into jet-range olefins in a single pass after a time on stream. In certain embodiments, the time on stream is at least 50 hours. In one embodiment, the time on stream is at least 60 hours.
In other embodiments, at least 80% of the mixture of C2 and C3+ olefins is converted into jet-range olefins in a single pass after a time on stream. In certain embodiments, the time on stream is at least 50 hours. In one embodiment, the time on stream is at least 60 hours.
In yet another embodiment, at least 90% of the mixture of C2 and C3+ olefins is converted into jet-range olefins in a single pass after a time on stream. In certain embodiments, the time on stream is at least 50 hours. In one embodiment, the time on stream is at least 60 hours.
In some embodiments using the single catalyst component with a mix of C2 and C4 olefins, at least 20% C2 olefin is converted into jet-range and/or diesel-range olefins in a single pass after a time on stream. In some examples, at least 40% C2 olefin is converted. In certain embodiments, from 25% to 80% C2 olefin is converted into jet-range and/or diesel-range olefins in a single pass after a time on stream. In one embodiment, from 40% to 75% C2 olefin is converted. In another embodiment, from 65% to 70% C2 olefin is converted.
In some other embodiments using the single catalyst component with a mix of C2 and C4 olefins, from 40% to 85% C4 olefin is converted into jet-range and/or diesel-range olefins in a single pass after a time on stream. In certain embodiments, from 45% to 80% C4 olefin is converted. In one embodiment, from 50% to 75% C4 olefin is converted. In another embodiment, from 65% to 70% C4 olefin is converted.
In yet other embodiments using the single catalyst component with a mix of C2 and C4 olefins, at least 40% C4 olefin is converted into jet-range and/or diesel-range olefins in a single pass after a time on stream. In certain embodiments, at least 45% C4 olefin is converted. In one embodiment, at least 50% C4 olefin is converted. In another embodiment, at least 65% C4 olefin is converted.
In some embodiments using the single catalyst component, at least 60% of the mixture of C2 and C4 olefins is converted into jet-range and/or diesel-range olefins in a single pass without recycling. In certain embodiments, at least 70% of the mixture of C2 and C4 olefins is converted into jet-range and/or diesel-range olefins in a single pass without recycling.
Embodiments of a reactor and a system for converting a feedstock comprising mixture of C2 and C3+ olefins into jet-range and, in some particular embodiments also diesel-range, olefins via co-oligomerization are disclosed herein. In some embodiments, the system comprises the reactor along with other system components.
In some embodiments, the reactor comprises a hybrid catalyst system or a single catalyst component as described herein. In certain embodiments, the hybrid catalyst system comprises a transition metal-based catalyst and an acid catalyst. In one embodiment, the transition-metal based catalyst and the acid catalyst are provided on separate catalyst beds. In another embodiment, the transition-metal based catalyst and the acid catalyst are provided on the same catalyst bed. In embodiments using a single catalyst component, the single catalyst component is provided on a single catalyst bed within the reactor.
In any of the foregoing or following embodiments, the hybrid catalyst system is provided in an amount sufficient to convert C2 and C3+ olefins into jet-range olefins via co-oligomerization. In other embodiments, the single catalyst component is provided in an amount sufficient to convert C2 and C4 olefins into jet-range and/or diesel-range olefins via co-oligomerization.
In some embodiments, the system comprises one or more storage containers, wherein each storage container independently contains a different olefin feedstock, such as a C2 olefin feedstock, a C3+ olefin feedstock, or combinations thereof. For example, in some embodiments, one storage container can house C3 olefins, a second storage container can house C4 olefins, a third storage container can house C5 olefins, and a fourth storage contain can house C2 olefins. In yet other embodiments, a single storage container can house a mixture of C3+ olefins (e.g., a mixture of C3, C4, and C5 olefins), or a mixture of C2 and C3+ olefins. Each storage container typically is maintained at a pressure lower than a vapor pressure of the olefin housed within the storage container.
In some embodiments, the system further comprises a high-pressure syringe pump manifold. The high-pressure syringe pump manifold can comprise one or more syringes that are configured to direct feedstocks housed in the storage containers into the reactor. In some embodiments comprising a plurality of syringes, the syringes are arranged in parallel configuration. In such embodiments, each syringe of the plurality can be independently and fluidly coupled to a storage container housing a feedstock component (e.g., storage containers housing C2 olefins, C3+ olefins, or combinations thereof).
In some embodiments, the reactor is connected to a storage container comprising a feedstock source comprising a mixture of C2 and C3+ olefins. In some other embodiments, the reactor is connected to a first storage container comprising the feedstock source comprising the C2 olefins and a second storage container comprising the feedstock source comprising the C3+ olefins. In one embodiment, the reactor is connected to a first storage container comprising feedstock source comprising C3 olefins, a second storage container comprising a feedstock source comprising C4 olefins, a third storage container comprising a feedstock source comprising C5 olefins, and a fourth storage container comprising a feedstock source comprising C2 olefins. In another embodiment, the reactor is connected to a first storage container comprising a feedstock source comprising C4 olefins and a second storage container comprising a feedstock source comprising C2 olefins. In some embodiments, the reactor is further connected to the high-pressure syringe pump manifold as described herein.
In some embodiments, the reactor is maintained at a pressure higher than the vapor pressure of the C3+ olefins during operation.
In some embodiments, the reacting pressure of the reactor ranges from 50 psig to 500 psig, such as 50 psig to 450 psig, or 55 psig to 400 psig, or 60 psig to 400 psig, or 70 psig to 350 psig, or 75 psig to 350 psig, or 75 psig to 300 psig, or 75 psig to 200 psig, or 75 psig to 150 psig, or 75 psig to 125 psig. In some embodiments, the pressure can range from 200 psig to 500 psig. In certain embodiments, the olefins are oligomerized under a pressure ranging from 75 to 500 psig, such as from 75 to 300 psig, or 75 psig to 200 psig. In one embodiment, the pressure is 100 psig. In another embodiment, the pressure is 200 psig.
In certain embodiments, the reacting pressure of the reactor ranges from 75 psig to 300 psig, such as 75 psig to 250 psig, or 75 psig to 200 psig, or 75 psig to 150 psig, or 75 psig to 120 psig, or 75 psig to 110 psig, or 75 psig to 100 psig. In particular embodiments, the reactor is operated at a pressure of 100 psig. In another embodiments, the reactor is operated at a pressure of 200 psig.
In some other embodiments, such as embodiments using a single catalyst component, the reacting pressure of the reactor can range from 75 psig to 500 psig, such as 80 psig to 500 psig, or 100 psig to 520 psig, or 100 psig to 500 psig, or 200 psig to 500 psig, or 75 psig to 300 psig, or 150 psig to 250 psig, or 160 psig to 240 psig, or 170 psig to 230 psig, or 180 psig to 220 psig, or 190 psig to 210 psig. In particular embodiments, the reactor is operated at a pressure of 200 psig. In another embodiments, the reactor is operated at a pressure of 100 psig.
In some embodiments, the method is conducted using a down-flow reactor arrangement. In such embodiments, the hybrid catalyst system is placed in the reactor, typically in an isothermal zone, and heated using a band heater to the desired reaction temperature. In some embodiments, the reactor comprises a single hybrid catalyst bed comprising a transition metal-based catalyst (e.g., Ni/SiO2—Al2O3 catalyst) and a zeolite catalyst, wherein the transition metal-based catalyst is positioned towards the top of the reactor, which is fluidly connected to the feedstock source container(s) such that the feedstock is first exposed to the transition metal-based catalyst; and wherein the zeolite catalyst is positioned towards the bottom of the reactor. In such embodiments, the feedstocks and a carrier gas (e.g., N2) are fed from the top of the reactor, and the flow rates of these gaseous feedstocks are controlled by mass flow controllers. In certain embodiments, liquid products can be collected at the bottom of the reactor in a cold trap (e.g., traps 112 in
Embodiments of methods for using a system for converting a feedstock comprising mixture of C2 and C3+ olefins into jet-range olefins via co-oligomerization also are disclosed herein.
In some embodiments, the method comprises contacting, in a single reactor as described herein, a feedstock comprising a mixture of C2 and C3+ olefins (e.g., C2 and C4 olefins) with a single catalyst component, and heating the single reactor at a temperature ranging from 100° C. to 500° C. to convert the feedstock into an oligomerized product composition comprising jet-range and/or diesel-range olefins via co-oligomerization. In certain embodiments, the single reactor is operated at a temperature ranging from 100° C. to 500° C., such as 150° C. to 500° C., or 200° C. to 500° C., or 250° C. to 500° C., or 250° C. to 400° C., or 250° C. to 300° C. In some embodiments, the temperature can range from 150° C. to 300° C. In one embodiment, the method comprises heating the single reactor at a temperature ranging from 250° C. to 300° C. to convert the feedstock into an oligomerized product composition comprising jet-range and/or diesel-range olefins via co-oligomerization.
In some embodiments, the method comprises contacting, in a single reactor as described herein, a feedstock comprising a mixture of C2 and C3+ olefins with a hybrid catalyst system comprising a transition-metal based catalyst and an acid catalyst, and heating the single reactor at a temperature ranging from 100° C. to 500° C. to convert the feedstock into an oligomerized product composition comprising jet-range olefins via co-oligomerization. In certain embodiments, the single reactor is operated at a temperature ranging from 100° C. to 500° C., such as 150° C. to 500° C., or 200° C. to 500° C., or 250° C. to 500° C., or 250° C. to 400° C., or 250° C. to 300° C., or 150° C. to 300° C. In one embodiment, the method comprises heating the single reactor at a temperature ranging from 250° C. to 500° C. to convert the feedstock into an oligomerized product composition comprising jet-range olefins via co-oligomerization. In another embodiment, the method comprises heating the single reactor at a temperature ranging from 250° C. to 300° C. to convert the feedstock into an oligomerized product composition comprising jet-range olefins via co-oligomerization.
In some embodiments, the method includes introducing the C2 olefin into the reactor, introducing the C3+ olefins into the reactor, contacting the mixture of C2 and C3+ olefins with the hybrid catalyst system (e.g., by allowing the feedstock to flow through the reactor and thus become exposed to the hybrid catalyst system), and heating the reactor to convert the mixture of C2 and C3+ olefins into an oligomerized product composition comprising jet-range olefins. In some embodiments, the oligomerized product composition further comprises non-jet-range products comprising olefins having carbon numbers lower than 8. In such embodiments, the reactor is heated at a temperature ranging from 100° C. to 500° C. In some embodiments, the single reactor is heated at a temperature ranging from 100° C. to 500° C., such as 150° C. to 500° C., or 250° C. to 500° C., or 250° C. to 300° C., or 150° C. to 450° C., or 150° C. to 400° C., or 150° C. to 350° C., or 150° C. to 300° C. In certain embodiments, the single reactor is heated at a temperature ranging from 250° C. to 500° C., such as 250° C. to 450° C., or 250° C. to 400° C., or 250° C. to 350° C., or 250° C. to 300° C. In one embodiment, the single reactor is heated at a temperature ranging from 250° C. to 300° C.
In further embodiments, the method comprises separating the jet-range olefins from the non-jet-range products and contacting the non-jet-range products with the hybrid catalyst system to produce jet-range olefins, such as by recycling the non-jet-range products back into the reactor.
In some other embodiments, the method comprises contacting, in a single reactor as described herein, a feedstock comprising a mixture of C2 and C4 olefins with a single catalyst component and heating the single reactor at a temperature ranging from 100° C. to 500° C. to convert the feedstock into an oligomerized product composition comprising jet-range and/or diesel-range olefins via co-oligomerization. In certain embodiment, the single reactor is heated at a temperature ranging from 100° C. to 500° C., such as 100° C. to 450° C., or 100° C. to 400° C., or 150° C. to 500° C., or 250° C. to 500° C., or 250° C. to 300° C., or 150° C. to 350° C., or 150° C. to 300° C. In certain embodiments, the single reactor is heated at a temperature ranging from 150° C. to 280° C., such as 160° C. to 280° C., or 180° C. to 280° C., or 200° C. to 260° C., or 210° C. to 250° C., or 215° C. to 245° C., or 220° C. to 240° C. In one embodiment, the single reactor is heated at a temperature ranging from 225° C. to 235° C.
In further embodiments, the method comprises separating the jet-range olefins from the non-jet-range products and contacting the non-jet-range products with the single catalyst system to produce jet-range olefins, such as by recycling the non-jet-range products back into the reactor.
Also described herein are embodiments of a combination comprising a feedstock as described herein and a catalyst system. In some embodiments, the feedstock of the combination comprises a mixture of olefins. In certain embodiments, the mixture of olefins comprises a mixture of C2 and C3+ olefins.
In some embodiments, the catalyst system is a single catalyst component, and the feedstock comprises a mixture of C2 and C4 olefins. In exemplary embodiments, the single catalyst component is a Ni-promoted BEA zeolite catalyst.
In some other embodiments, the catalyst system is a hybrid catalyst system. In further embodiments, the hybrid catalyst system of the combination is the hybrid catalyst system as described herein. In certain embodiments, the hybrid catalyst system of the combination comprises a transition metal-based catalyst and an acid catalyst. In one embodiment, the transition-metal based catalyst comprises Ni/SiO2—Al2O3, the acid catalyst comprises ZSM-5 zeolites having a Si/Al ratio ranging from 10 to 300.
Disclosed herein are embodiments of a method, comprising: contacting, in a single reactor, a feedstock comprising a mixture of C2 and C3+ olefins with a hybrid catalyst system comprising a transition-metal based catalyst and an acid catalyst; and heating the single reactor at a temperature ranging from 250° C. to 500° C. to convert the feedstock into an oligomerized product composition comprising jet-range olefins via co-oligomerization.
The any or all embodiments, the oligomerized product composition further comprises non-jet-range products.
In any or all of the above embodiments, the method further comprising separating the jet-range olefins from the non-jet-range products; and/or contacting the non-jet-range products with the hybrid catalyst system to produce jet-range olefins.
In any or all of the above embodiments, contacting the feedstock with the hybrid catalyst system comprises (i) contacting the feedstock with the transition-metal based catalyst, which is provided in a first catalyst bed contained within the single reactor to produce a first product mixture and then contacting the first product mixture with the acid catalyst, which is provided in a second catalyst bed contained within the single reactor to convert the first product mixture into the oligomerized product composition; or (ii) contacting the feedstock with the transition-metal based catalyst and the acid catalyst, wherein the transition-metal based catalyst and the acid catalyst are provided on the same catalyst bed in the single reactor.
In any or all of the above embodiments, the oligomerized product composition comprises 0 wt % to less than 5 wt % aromatics.
In any or all of the above embodiments, the feedstock is derived from a heterogeneous carbonaceous feed source via methanol synthesis and a methanol-to-olefin process.
In any or all of the above embodiments, the feedstock comprises mixed olefins with a C3+:C2 molar ratio ranging from 5:1 to 1:5.
In any or all of the above embodiments, the C3+ olefins comprise olefins having a carbon number of C3, C4, C5, or a combination of such olefins.
In any or all of the above embodiments, the jet-range olefins comprise olefins having carbon numbers ranging from C8 to C16.
In any or all of the above embodiments, the temperature ranges from 250° C. to 300° C.
In any or all of the above embodiments, the method is carried out under a pressure ranging from 75 psig to 300 psig.
In any or all of the above embodiments, the transition-metal based catalyst comprises nickel (Ni).
In any or all of the above embodiments, the transition-metal based catalyst is Ni/SiO2—Al2O3.
In any or all of the above embodiments, the acid catalyst comprises a ZSM-5 zeolite having a Si/Al ratio ranging from 10 to 250.
In any or all of the above embodiments, the method provides a single pass conversion of the mixture of C2 and C3+ olefins into jet-range olefins of at least 90% after a time on stream of at least 60 hours.
In any or all of the above embodiments, a ratio of the jet-range olefins to the non-jet-range products is at least 65%.
Also disclosed are embodiments of a reactor for performing the method according to any or all of the above embodiments, the reactor comprising a hybrid catalyst system comprising a transition-metal based catalyst and an acid catalyst, wherein the transition-metal based catalyst and the acid catalyst are provided on separate catalyst beds or on the same catalyst bed and the hybrid catalyst system is provided in an amount sufficient to convert C2 and C3+ olefins into jet-range olefins via co-oligomerization.
In any or all of the above embodiments, the reactor is further connected to (i) a feedstock source comprising the mixture of C2 and C3+ olefins or a first feedstock source comprising the C2 olefins and a second feedstock source comprising the C3+ olefins; (ii) a high-pressure syringe pump manifold comprising one or more syringes; or (iii) a combination of (i) and (ii).
Also disclosed are embodiments of a combination, comprising a feedstock comprising a mixture of C2 and C3+ olefins; and a hybrid catalyst system comprising a transition-metal based catalyst and an acid catalyst.
In any or all of the above embodiments, the transition-metal based catalyst comprises Ni/SiO2—Al2O3, the acid catalyst comprises ZSM-5 zeolites having a Si/Al ratio ranging from 10 to 250.
Also disclosed are embodiments of a method, comprising contacting, in a single reactor, a feedstock comprising a mixture of C2 and C4 olefins with a single catalyst component comprising a transition-metal based catalyst and an acid catalyst; and heating the single reactor at a temperature ranging from 150° C. to 300° C. to convert the feedstock into an oligomerized product composition comprising jet-range and/or diesel-range olefins via co-oligomerization.
All experiments were performed in a packed bed reactor system. Nickel introduction into catalyst embodiments was achieved by wetness impregnation, incipient wetness impregnation, or ion exchange. Several pretreatment strategies were also evaluated, including both pre-reduction in hydrogen and thermal treatment in flowing nitrogen.
Baseline catalyst preparation—The baseline catalyst was prepared via ion exchange of an amorphous silica alumina catalyst (Davicat SiAl 3113) with nickel chloride via the following procedure: The silica alumina support was calcined at 550° C. prior to ion exchange. Ion exchange was achieved by heating a stirred mixture of the silica alumina support, NiNO3 and water to 90° C. under reflux for 24 hours. After ion exchange the catalyst was washed thoroughly with warm deionized water and dried at 90° C. overnight. The dried catalyst was then pelletized and loaded into the flow reactor system. Prior to reaction, the catalyst was pretreated at 300° C. in flowing N2 at atmospheric pressure before cooling to the reaction temperature.
Product Analysis—products were analyzed via gas chromatography—mass spectroscopy (GC-MS) and quantified with a flame ionization detector (FID). The gaseous products were passed through a flow meter (DryCal) and their composition was analyzed in a gas chromatography—thermal conductivity detector (GC-TCD). Although the typical temperature range in which the experiments were performed are 200-300° C., most of the oligomerization experiments were carried out 275° C. The typical reaction pressure used herein was 100 psig with a weigh hourly space velocity 0.6-1.8 h−1.
Preparation of Hybrid/Catalyst—Ni/SiO2—Al2O3 catalyst was prepared via ion exchange of an amorphous silica alumina catalyst (Davicat SiAl 3113) with NiNO3 via the following procedure.
The silica alumina support was calcined at 550° C. prior to ion exchange. Ion exchange was achieved by heating a stirred mixture of the silica alumina support, NiNO3 and water to 98° C. under reflux for 24 hours. After ion exchange the catalyst was washed thoroughly (5-6 times) with warm deionized water and dried at 90° C. overnight. The dried catalyst was then pelletized and loaded into the flow reactor system. Prior to reaction the catalyst was pretreated at 300° C. in flowing N2 at atmospheric pressure. The typical Ni loading used in this catalyst was 2 wt % which was determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES). Different zeolite catalysts used in this example were commercially available and obtained from Zeolyst Internationals. Prior to loading in the reactor, all the zeolite materials were pelletized and calcined at 550° C. for 4 hours under air.
In this example, ethylene oligomerization over a baseline Ni-SiAl catalyst was evaluated at a temperature of 150° C. and pressure of 300 psig. Ethylene oligomerization was performed at 150° C. and 300 psig. The ethylene (and other olefins as appropriate) conversion was monitored via online gas chromatography and liquid products were sampled every 24 hours.
In this example, propylene oligomerization over a Ni/SiAl catalyst at 200° C. was evaluated. Nearly 60% of the propylene conversion was noted at this condition and no deactivation was observed for 24 hours. The liquid obtained as the product was analyzed by GC which shows the presence of C6 and C9 compounds predominantly with selectivity to 66% and 28%, respectively. A minor amount of C12 was also noted in the product stream.
In this example, the co-oligomerization of ethylene/propylene on Ni/SiO2—Al2O3 catalyst at 200° C. and 275° C. was evaluated. Co-oligomerization of a mixture of ethylene and propylene (1:1 molar ratio) was initially carried out at 150° C., the temperature used for baseline ethylene oligomerization; however, only butene was obtained as a product, which suggested that propylene was not reactive at this temperature. When the temperature was increased to 200° C., a significant amount of cross-oligomerization between C2 and C3 was noted which yielded C5 as the major product with selectivity to 48%. In addition to the cross-oligomerization, self-oligomerization of ethylene and propylene was also noted which resulted in different C4 (30% selectivity) and C6 (16% selectivity) as the products, respectively. In this particular example, nearly 3 times higher selectivity to C5 compared to C6 further indicated that majority of the propylene underwent cross oligomerization with ethylene compared to reacting with itself. The overall conversion of C2 and C3 was noted at 55%. The conversion and selectivity of the product remained same ever after 40 hours after which the overall conversion decreased by 10%. Upon increasing the reaction temperature to 275° C., the overall conversion of C2 and C3 was further increased to 75%. The analysis of the liquid sample obtained as the product shows very similar to the product distribution noted at 200° C. In this particular example, the results suggested that although increasing temperature significantly influence the activity of co-oligomerization, it merely affected the product distribution.
In this particular example, liquid products accounted for 95% of mass balance and thus suggests little to no over-oligomerization in all these cases. While the co-oligomerization of C2 and C3 olefin (stability>40 hours on TOS) with product selectivity to 60-65% for C5+ products has been demonstrated in this particular example, it mostly comprised of C5 and C6.
In this example, the co-oligomerization of ethylene/propylene using a hybrid catalyst system containing Ni/SiO2—Al2O3 and zeolite catalyst at 275° C. was evaluated. A hybrid catalyst bed was used, which included the Nickel catalyst and the ZSM-5 zeolite to promote an acid catalyzed oligomerization pathway and enable C5+ olefins (that are generated in-situ upon oligomerization of C2 and C3 on Ni catalyst) to oligomerize further to generate higher olefins suitable for jet range. In this example, when a mixture of ethylene and propylene was reacted at 275° C. using the hybrid catalyst system, the majority of products obtained were in the C10-C15 range. Using the hybrid catalyst bed not only improved the selectivity to desired products but also increased the single pass conversion to 90-95%.
In this example, co-oligomerization of mixed olefins as described above in Example 4 was performed with similar conditions but using a stage bed configuration in which a Ni/SiO2—Al2O3 catalyst bed and the ZSM-5 catalyst bed were placed consecutively. This configuration of the reactor allowed the olefins (i.e., ethylene and propylene) to react with the Ni/SiO2—Al2O3 first and the resultant product (i.e., C4-C6) then further reacts with ZSM-5 which resulted in products with longer carbon chain length (typical range C8-C16).
In this example, oligomerization in a mixed bed configuration was also carried out wherein the amounts of both Ni/SiO2—Al2O3 and ZSM-5 catalyst were mixed together first and then placed in the reactor.
In this example, the impact of acidity of zeolites catalyst on the co-oligomerization of ethylene and propylene was evaluated. Co-oligomerization of C2 and C3 was evaluated with different ZSM-5 catalysts with varying Si/Al ratio (i.e., varying Bronsted acidity). In this example, as demonstrated in
The total product selectivity akin to jet range (e.g., C8-C16) was also analyzed and demonstrated in
In this example, the effect of other zeolites with different structures and pore size on oligomerization activity was evaluated. Mordenite (CBV 21A), a one-dimensional zeolite shows an overall conversion 80%, but with a low amount of products in jet fuel range in particular embodiments. Without being limited to a single operating theory, it currently is believed that any low mass balance obtained in particular example may result from formation of polymeric products. Faujasite (CBV 901), a commercially available zeolite with 3D pore structures similar to ZSM-5 albeit larger pore size, also was evaluated. 72% overall conversion was observed in this example.
In this example, upon optimization of both Ni2+ (Ni/SiO2—Al2O3 ) and acid catalyst (ZSM-5 zeolite, CBV 8014), the impact of ethylene and propylene composition in the feed on the corresponding product selectivity was evaluated. Different mixtures with varying molar ratios of C3/C2, such as 2, 1 and 0.5 were prepared and used as feed. When subjected to oligomerization with the hybrid catalyst at 275° C., all these different feeds composition resulted in very similar product spectrum that are composed of different compounds with different carbon numbers which are typically in the range between C4-C16. Product selectivity corresponding to the jet range i.e., C8-C16 was further calculated from GC-FID.
In this example, it is evident from the
In this example, the results demonstrate the ability of the current process to oligomerize a wide variety of feeds while still resulting in a product suitable for jet fuel. As shown in
Propylene oligomerization at the same reaction condition was carried out using Ni/SiO2—Al2O3 and MFI catalyst. Although wide distribution of products (C4-C16) was obtained, a significant amount of aromatics species such as xylene or naphthalene derivatives were noted. In this example, absence of these species during co-oligomerization suggests that the underlying reaction mechanism corresponding to cross-oligomerization between C2 and C3 are very different such that it prevented the formation of aromatics.
In this example, the impact of different feedstock compositions and different temperatures on the corresponding product selectivity was evaluated using a hybrid catalyst comprising Ni/SiO2—Al2O3 and ZSM-5 zeolite. Feedstocks with different compositions (C2-C3 with a molar ratio C2:C3=1:1, and C2 -C5 with a molar ratio C2:C3:C4:C5=1:1:1:1) were subjected to oligomerization under different temperatures (250° C. and 275° C.). The operation pressure was 100 psig and the WHSV (weight-hourly space velocity) was 0.8 h−1.
In this example, the impact of feedstock composition with different molar ratios of C2:C3:C4:C5 on the corresponding product selectivity was evaluated using a hybrid catalyst comprising Ni/SiO2—Al2O3 and ZSM-5 zeolite under the temperature of 250° C. The operation pressure was 100 psig and the WHSV was 0.8 h−1.
Examples 1-11 establish an efficient process that can be used to oligomerize mixed olefin feedstocks in a single reactor unit that uses hybrid catalyst system comprised of Ni/SiAl and MFI zeolite was demonstrated. 90% single pass conversion of C2 and C3 was obtained with 70% product selectivity that are distributed in the C8-C15 range, ideal for aviation fuel. In the examples, the products obtained are comprised of n- or iso-alkenes and no traces of aromatics were observed in the product stream. The remaining 30% products which mostly included C3-C7 olefins would be recycled to undergo further oligomerization and improve the efficiency of the overall catalytic process.
Solid Acid Catalyst Synthesis—Solid acid catalysts evaluated included commercially available materials including BEA, H—Y, H-ZSM-5 from Zeolyst. The zeolite powder was pelletized using a pneumatic laboratory press (2-ton pressure force for 1 minute) before being crushed and sieved to the desired particle size (60 to 100 mesh). Before loading the reactor, the zeolites were calcined in a muffle furnace at 500° C. for 4 hours. Ni was impregnated onto support materials via incipient wetness with a Cu nitrate precursor solution dissolved in deionized water. After impregnation, the catalysts were dried at 120° C. for 8 hours and calcined at 500° C. for 4 hours.
Catalytic Activity—Performance evaluations for the oligomerization catalysts were performed in a single fixed-bed reactor. A liquid feed of olefins was transported with an ISCO syringe pump and mixed with a flow of N2 prior to being fed into the reactor. WHSV (weight-hourly space velocity) was calculated based on the mass flow of olefins per weight of catalyst in an hourly basis (i.e., gfeed gcat−1 h−1). All reactors used a K-type thermocouple placed in the middle of the catalyst bed. To minimize temperature gradients within the reactor zone, an electrical resistance heating block was used for temperature control. Gaseous effluent was analyzed online using an Inficon micro GC (Model 3000A) equipped with MS-5A, Plot U, alumina, and OV-1 columns, and a thermal conductivity detector. Liquid samples collected from the knockout pot were analyzed separately ex situ using liquid chromatography (for aqueous products) and gas chromatography-mass spectrometry (GC-MS) (for hydrocarbon products).
Catalyst characterization—Oligomerization liquid products comprised complex mixtures of olefins. GC-MS was used to characterize the products and estimate carbon numbers. Quantification of the mass composition of particular compounds or groups of compounds was performed using two parameters: 1) the flame ionization detector (FID) GC integrated area for a particular peak, and 2) identification based on the best match to the mass spectrometry library data. Simulated distillation profiles of the olefin product were determined following the method ASTM D2887 using the GC results of an FID equipped gas chromatograph. Mass yields were based on GC-FID response.
In this example, a 4:1 (mol C) mixture of butene/ethene was used as model feed for oligomerization studies using solid acid catalysts. Catalytic performance as a function of solid acid catalysts (e.g., HY, MCM-41, BEA) was evaluated and results are summarized in Table 2. In this example, for all three catalytic materials shown in Table 2, the ethene conversion was approximately 50% and the conversion of n-butene is slightly higher (57-74%). Without being limited to a single operating theory, it currently is believed that the results suggest that BEA offers higher conversion of both ethene and butene; however, at the expense (in at least some examples) of a lower product selectivity to olefin (desired) versus paraffin (undesired). For example, butane in the C4 fraction is 5.3% with BEA, while only 1.6% and 1.3% was observed for HY and MCM-41, respectively.
In this example, catalytic performance for oligomerization of a mixture of butene and ethene over BEA zeolite was evaluated as a function of olefin feed concentration and operating temperature. For comparison purpose, ethene feed (without butene) was also evaluated as a function of operating temperature and pressure. As the olefin feed concentration is decreased from 63% to 17.0% butene (keeping the same 4:1 molar carbon ratio of ethene in the feed), the ethene conversion nearly doubles from 25% to 48%; however, the butene conversion remains approximately the same at 50%. When the operating temperature was increased from 200° C. to 230° C. the ethene conversion and butane/butene product ratio were essentially unchanged. Further, the butene conversion only marginally increased from 52% to 60%.
When ethene is fed without butene, under otherwise identical conditions at 200° C., the ethene conversion decreases from 25% (with butene) to 6% (without butene). In this example, the result suggests that ethene is in fact co-oligomerizing with butene. Additionally, with only ethene in the feed, saturation of the predominantly C4 product is pronounced (with 94% butane). By comparison, with butene in the feed the C4 product saturation is minimal (with 2.9% butane). When the temperature of the ethene-only feed is increased from 200° C. to 230° C. the ethene conversion largely remains at a low level (<7%). However, when the pressure is increased from 200 to 500 psig the ethene conversion increases significantly from 4.9% to 91%.
In this example, however, this high of a conversion also comes with increased saturation of the product C4 (with 89% butane). Taken together, but without being limited by a single theory of operation, it currently is believed that these results in this example suggest that ethene is co-oligomerized with butene and it can be accomplished over BEA zeolite with reasonable conversions (up to 50% ethene and butene conversions) and with minimal saturation of the olefinic products (<3% alkanes).
In this example, catalytic performance results for mixed butene/ethene oligomerization whereby Ni was incorporated into BEA zeolite, SiO2—Al2O3 (referred to as “Olig-1” in Table 4, below), and MCM-41 solid acid catalysts are shown in Table 4 for select tests. The effect of different Ni loadings and operating temperatures was also investigated. When Ni loading of BEA was increased from 1% to 5% the ethene conversion increased from 40% to 69% (Table 4, entry 1 and 5). Further, the butene conversion increased from 55% to 69%. Most interestingly, this boost in conversion came with no consequence of increased olefin saturation. In both cases the alkane content of the C4 cut was less than 2%. Additional enhancement to conversion was achieved by increasing the operating temperature from 200° C. to 230° C. Here the ethene and butene conversions were increased from 69% to 78%, and 69% to 73%, respectively (Table 4, entry 5 and 6). There was also little consequence of olefin saturation under these conditions (<2% butane in C4 cut). While ethene and butene conversion levels and degrees of saturation were achieved in some examples with Ni incorporated SiO2—Al2O3 (“Olig-1”) and MCM-41 supports, the products observed for these catalysts were not, in some embodiments, as selective to the jet-range as for Ni-promoted BEA.
In view of the many possible embodiments to which the principles of the present disclosure may be applied, it should be recognized that the illustrated embodiments are only preferred examples of the present disclosure and should not be taken as limiting the scope of the present disclosure. Rather, the scope of the present disclosure is defined by the following claims. We therefore claim as our present disclosure all that comes within the scope and spirit of these claims.
This invention was made with government support under Contract DE-AC05-76RL01830 awarded by the U.S. Department of Energy. The government has certain rights in the invention.
