SYSTEM AND METHOD FOR HYDROTREATMENT OF AROMATIC FUEL

Description

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. Provisional Patent Application No. 63/733,977, filed Dec. 13, 2024, the content of which is hereby incorporated by reference in its entirety.

BACKGROUND

In recent years, sustainable aviation fuel (SAF) has been highlighted as a promising way to decarbonize the airline industry. Already existing technologies, including Sugars to Aromatics (S2A) and Ethanol to Aromatics (E2A) technologies, produce synthetic aromatic kerosene (SAK), which is a necessary blending component to produce 100% drop-in SAF. Two primary pathways to produce SAK have been identified and practiced: caustic and clay treatment of Narrow Range SAK (NRSAK), which produces a C₉-C₁₀ fraction; or hydrotreating of Broad Range SAK (BRSAK), which produces a C₉-C₁₇ cut. NRSAK contains very low level of naphthalenes, so caustic treatment is sufficient to remove oxygenates to meet jet fuel specifications. However, BRSAK contains both naphthalenes and oxygenates, both of which need to be removed to meet jet fuel specifications, so caustic treatment is insufficient. Therefore, a need exists for methods to hydrotreat the BRSAK fraction.

Others have investigated hydrotreating both BRSAK and full range aromatic feedstock, which consists of C5+ species, with sulfided catalysts. While promising results were obtained for hydrotreating the BRSAK fraction, there is significant interest in using non-sulfided catalysts, due to the complications associated with addition and then later removal of sulfur species. For hydrotreating the full range aromatic feedstock, a pressure drop followed by reactor plugging was observed.

Accordingly, there is a need for methods and systems which enable removal of naphthalenes and oxygenates from broad range synthetic aromatic kerosene.

SUMMARY OF THE INVENTION

The present disclosure relates to methods and systems for producing aromatic products. In one aspect, the present disclosure provides a method for producing an aromatic product. The method includes feeding a primary feed stream into a primary hydrotreating (HT) reactor, the primary feed stream comprising (1) C₆₊ aromatic compounds, which include a C₁₀₊ polyaromatic compound and (2) C₂₊O₁₊ oxygenates. The method also includes feeding hydrogen into the primary HT reactor. The method further includes reacting the primary feed stream with the hydrogen in the presence of a primary HT catalyst in the primary HT reactor to produce an aromatic product. At least one of (1) the C₁₀₊ polyaromatic compound and (2) the C₂₊O₁₊ oxygenates in the aromatic product is reduced relative to the primary feed stream. The primary HT catalyst is essentially free of sulfur. In some embodiments, the method further includes reacting a crude feed stream with hydrogen in the presence of a selective HT catalyst in a selective HT reactor to produce the primary feed stream. The crude feed stream includes: (1) the C₆₊ aromatic compounds, which comprise the C₁₀₊ polyaromatic compound and (2) the C₂₊O₁₊ oxygenates. The C₁₀₊ polyaromatic compound is reduced in the primary feed stream relative to the crude feed stream.

In another aspect, the present disclosure provides a method for producing an aromatic product. The method includes reacting a crude feed stream with hydrogen in the presence of a selective hydrotreating (HT) catalyst in a selective HT reactor to produce a primary feed stream; and reacting the primary feed stream with hydrogen in the presence of a primary HT catalyst in a primary HT reactor to produce the aromatic product. The crude feed stream comprises: (1) C₆₊ aromatic compounds, which comprise a C₁₀₊ polyaromatic compound and (2) C₂₊O₁₊ oxygenates. At least one of (1) the C₁₀₊ polyaromatic compound and (2) the C₂₊O₁₊ oxygenates are reduced in the aromatic product relative to the crude feed stream.

In another aspect, the present disclosure provides a system for producing an aromatic product. The system can include a selective hydrotreating (HT) reactor comprising a selective HT catalyst and a first inlet configured to receive a crude feed stream. The selective HT reactor can be configured to react the crude feed stream with hydrogen in the presence of the selective HT catalyst to produce a primary feed stream. The system can also include a primary HT reactor comprising a primary HT catalyst and a second inlet is configured to receive the primary feed stream produced in the selective HT reactor. The primary HT reactor can be configured to react the primary feed stream with hydrogen in the presence of the primary HT catalyst to produce the aromatic product.

In another aspect, the present disclosure also provides an aromatic product produced by the method as described herein. Further provided is an aromatic jet-range fuel product comprising the aromatic product as described herein. Further provided is a sustainable aviation fuel (SAF) comprising the aromatic product as described herein blended with a paraffinic sustainable fuel.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a schematic illustration of a system in accordance with some embodiments of the present disclosure.

FIG. 2 shows oxygenate content over time on stream for Pd/Al₂O₃ catalyst. Conditions were selected to maximize monoaromatic content while partially saturating naphthalenes and remove oxygenates. Oxygenate breakthrough observed around 15 days on stream (DoS).

FIG. 3 shows oxygenate breakthrough over time (DoS) for two loadings of the same PtPd/Al₂O₃ catalyst. In one case (dark dots, dark circles), no SHU reactor was used upstream. In the second case (light dots, light circle), a SHU reactor was used upstream to remove species that coke the catalyst.

DETAILED DESCRIPTION OF THE INVENTION

Disclosed herein are methods and systems for producing an aromatic product, an aromatic product, and a sustainable aviation fuel.

In one aspect, the present disclosure provides a method for producing an aromatic product, the method comprising:

• • feeding a primary feed stream into a primary hydrotreating (HT) reactor, the primary feed stream comprising (1) C₆₊ aromatic compounds, which include a C₁₀₊ polyaromatic compound and (2) C₂₊O₁₊ oxygenates;
  • feeding hydrogen into the primary HT reactor; and
  • reacting the primary feed stream with the hydrogen in the presence of a primary HT catalyst in the primary HT reactor to produce an aromatic product, at least one of (1) the C₁₀₊ polyaromatic compound and (2) the C₂₊O₁₊ oxygenates in the aromatic product being reduced relative to the primary feed stream, the primary HT catalyst being essentially free of sulfur.

In some embodiments, the method disclosed herein further include reacting a crude feed stream with hydrogen in the presence of a selective HT catalyst in a selective HT reactor to produce the primary feed stream. The crude feed stream includes: (1) the C₆₊ aromatic compounds, which comprise the C₁₀₊ polyaromatic compound and (2) the C₂₊O₁₊ oxygenates. The C₁₀₊ polyaromatic compound is reduced in the primary feed stream relative to the crude feed stream.

In another aspect, the present disclosure provides a method for producing an aromatic product, the method including: reacting a crude feed stream with hydrogen in the presence of a selective hydrotreating (HT) catalyst in a selective HT reactor to produce a primary feed stream, and reacting the primary feed stream with hydrogen in the presence of a primary HT catalyst in a primary HT reactor to produce the aromatic product. The crude feed stream includes: (1) C₆₊ aromatic compounds, which comprise a C₁₀₊ polyaromatic compound and (2) C₂₊O₁₊ oxygenates. In particular, at least one of (1) the C₁₀₊ polyaromatic compounds and (2) the C₂₊O₁₊ oxygenates are reduced in the aromatic product relative to the crude feed stream. In some embodiments, the primary HT catalyst is essentially free of sulfur. In some embodiments, the C₁₀₊ polyaromatic compound is reduced in the primary feed stream relative to the crude feed stream.

Unless otherwise defined herein, the term “reduce,” “reducing,” “reduced,” or the like in connection with a substance (e.g., polyaromatic compounds or oxygenates) refers to reduction in quantities or concentration (e.g., as measured by weight percentage or wt %). Such term is understood to have the same meaning as “decrease” or “lowering” in describing a change in quantity.

The methods disclosed herein can include a crude feed stream. The crude feed stream includes: (1) the C₆₊ aromatic compounds, which comprise the C₁₀₊ polyaromatic compound and (2) the C₂₊O₁₊ oxygenates. In some embodiments, the crude feed stream comprises C₈₊ aromatic compounds. In some embodiments, the crude feed stream includes C_8-17 aromatic compounds. In some embodiments, the crude feed stream comprises narrow range synthetic aromatic kerosene (NRSAK), broad range synthetic aromatic kerosene (BRSAK), or combinations thereof.

In some embodiments, the crude feed stream includes C₇-C₁₇ compounds. In some embodiments, the crude feed stream may include C₈-C₁₇ compounds. As a nonlimiting example, the crude feed stream can include monoaromatics (e.g., about 90 wt %), naphthalenes (e.g., about 3 wt %), cycloparaffins (e.g., about 5 wt %), and hydrocarbon oxygenates (e.g., about 3 wt %).

The methods and systems disclosed herein include a primary feed stream. The primary feed stream may include (1) C₆₊ aromatic compounds, which may include a C₁₀₊ polyaromatic compound and (2) C₂₊O₁₊ oxygenates. In some embodiments, the primary feed stream contains 90 wt % monoaromatics, 3 wt % naphthalenes, 3 wt % oxygenates, and 4 wt % cyclic paraffins.

In some embodiments, the primary feed stream includes C₇-C₁₇ compounds. In some embodiments, the primary feed stream includes C₈₊ aromatic compounds. In some embodiments, the primary feed stream includes C₈-C₁₇ compounds. In some embodiments, the primary feed stream comprises C_8-17 aromatic compounds. As a nonlimiting example, the primary feed stream can include monoaromatics (e.g., about 90 wt %), naphthalenes (e.g., about 1 wt %), cycloparaffins (e.g., about 5 wt %), and hydrocarbon oxygenates (e.g., about 3 wt %).

The methods disclosed herein can produce an aromatic product from the primary feed stream. The aromatic product can include a reduction of at least one of (1) the C₁₀₊ polyaromatic compound and (2) the C₂₊O₁₊ oxygenates relative to the primary feed stream. In some embodiments, the C₁₀₊ polyaromatic compound is less than 2.0 wt %, less than 1.5 wt %, less than 1.0 wt %, less than, 0.9 wt %, less than 0.8 wt %, less than 0.7 wt %, less than 0.6 wt %, less than 0.5 wt %, less than 0.4 wt %, less than 0.3 wt %, less than 0.2 wt %, or less than 0.1 wt % in the aromatic product. In some embodiments, the C₁₀₊ polyaromatic compound is less than 0.5 wt % in the aromatic product. In some embodiments, the C₂₊O₁₊ oxygenates are less than 3000 ppm, less than 2000 ppm, less than 1000 ppm, less than 900 ppm, less than 800 ppm, less than 700 ppm, less than 600 ppm, less than 500 ppm, less than 400 ppm, less than 300 ppm, less than 200 ppm, or less than 100 ppm in the aromatic product. In some embodiments, the C₂₊O₁₊ oxygenates are less than 500 ppm or less than 200 ppm in the aromatic product.

The C₆₊ aromatic compounds as used herein may include monoaromatic compounds and polyaromatic compounds. Monoaromatic compounds include benzene and substituted benzenes, such as C₈-C₁₆ alkylbenzenes. C₈ alkylbenzenes include, for example, p-xylene, m-xylene, o-xylene, and ethylbenzene. C₉ alkylbenzenes include, for example, 1-methyl-3-ethylbenzene, 1-methyl-4-ethylbenzene, 1,3,5-trimethylbenzene, 1,2,4-trimethylbenzene, isopropyl benzene, n-propylbenzene, 1-methyl-2-ethylbenzene, and 1,2,3-trimethylbenzene. C₁₀ alkylbenzene include, for example, sec-butylbenzene, 1,3-diethylbenzene, 1-methyl-3-n-propylbenzene, 1-methyl-4-n-propylbenzene, 1,3-dimethyl-5-ethylbenzene, 1,4-diethylbenzene, 1-methyl-3-isopropylbenzene, 1-methyl-4-isopropylbenzene, 1-methyl-2-n-propylbenzene, 1,4-dimethyl-2-ethylbenzene, 1,3-dimethyl-4-ethylbenzene, 1,2-dimethyl-4-ethylbenzene, 1,2,4,5-tetramethylbenzene, and tetralin.

In some embodiments, the crude feed stream or the primary feed stream includes at least 80 wt %, at least 85 wt %, at least 90 wt %, or at least 95 wt % C₆₊ aromatic compounds. In some embodiments, the crude fee stream or the primary feed stream comprises at least 90 wt % C₆₊ aromatic compounds. In some embodiments, the aromatic product comprises at least 75 wt %, at least 80 wt %, at least 85 wt %, at least 90 wt %, or at least 95 wt % C₆₊ aromatic compounds. In some embodiments, the aromatic product comprises at least 80 wt % C₆₊ aromatic compounds.

The C₁₀₊ polyaromatic compounds can include C₁₀-C₁₈ polycyclic aromatic hydrocarbons (PAHs), such as naphthalene (C₁₀), phenalene (C₁₃), anthracene (C₁₄), phenanthrene (C₁₄), pyrene (C₁₆), and tetracene (C₁₈), and alkyl-substituted versions thereof. The polyaromatic compounds (e.g., naphthalenes) can be at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, or at least 6%, by weight in the crude feed stream. In some embodiments, the polyaromatic compounds is at least 3% by weight in the crude feed stream. The polyaromatic compounds (e.g., naphthalenes) can be at least 0.1%, at least 0.2%, at least 0.3%, at least 0.4%, at least 0.5%, at least 0.6%, at least 0.7%, at least 0.8%, at least 0.9%, or at least 1.0%, by weight in the primary feed stream. In some embodiments, the polyaromatic compounds is at least 1.0% by weight in the primary feed stream. The polyaromatic compounds (e.g., naphthalenes) can be 1% or less, 0.8% or less, 0.6% or less, 0.4% or less, 0.2% or less, or 0.1% or less, by weight in the aromatic product. In some embodiments, the polyaromatic compounds is 0.5% or less by weight in the aromatic product. As a nonlimiting example, the polyaromatic compounds can be about 3% by weight in the crude feed stream, about 1.0% by weight in the primary feed stream, and about 0.5% by weight in the aromatic product.

The C₂₊O₁₊ oxygenates can include, for example, phenols, hydroxyindanes, etc. The oxygenate can be at least 0.05% by weight, at least 0.1% by weight (or 1,000 ppm), at least 0.25% by weight, at least 0.5% by weight, at least 0.75% by weight, at least 1.0% by weight (or 10,000 ppm), at least 1.25% by weight, at least 1.50% by weight, at least 1.75% by weight, at least 2.0% by weight, at least 2.25% by weight, at least 2.50% by weight, at least 2.75% by weight, at least 3.0% by weight (or 30,000 ppm), at least 3.25% by weight, at least 3.50% by weight, at least 3.75% by weight, in the crude feed stream or the primary feed stream. In contrast, the oxygenate can be 1,000 ppm or less, 800 ppm or less, 600 ppm or less, 400 ppm or less, 200 ppm or less, or 100 ppm or less by weight in the aromatic product. As a nonlimiting example, the oxygenate can be about 30,000 ppm by weight in the crude feed stream or the primary feed stream and about 200 ppm by weight in the aromatic product.

The composition of the aromatic product (such as the contents of the C₁₀₊ polyaromatic compound or the C₂₊O₁₊ oxygenates) may be maintained for a duration of the present method (e.g., 1-30 days). In some embodiments, the C₂₊O₁₊ oxygenates in the aromatic product may be maintained at less than 500 ppm, less than about 750 ppm, less than about 1000 ppm, less than about 2000 ppm, or less than about 3000 ppm for at least 25 days, at least 24 days, at least 23 days, at least 22 days at least 21 days, at least 20 days, at least 19 days, at least 18 days, at least 17 days, at least 16 days, at least 15 days, at least 14 days, at least 13 days, at least 12 days, at least 11 days, at least 10 days, at least 9 days, at least 8 days, at least 7 days, at least 6 days, at least 5 days, at least 4 days, at least 3 days, at least 2 days, or at least 1 day. In some embodiments, the C₂₊O₁₊ oxygenates in the aromatic product are maintained at less than 500 ppm for at least 10 days.

The methods disclosed herein can include a primary hydrotreating (HT) catalyst and a selective HT catalyst. The primary and selective HT catalysts used herein can include a platinum group metal (PGM), such as Pt, Pd, Rh, Os, Ir, Ru, Re, or alloys thereof. The HT catalysts can also include a support, such as Al₂O₃, ZrO₂, and silica aluminates. In some embodiments, the primary HT catalyst includes a platinum group metal and a support. In some embodiments, the primary HT catalyst includes Pt—Pd/Al₂O₃. In some embodiments, the primary and selective HT catalysts include a non-PGM catalyst. In some embodiments, the primary and selective HT catalysts may be substantially the same catalyst.

In some embodiments, the selective HT catalyst comprises a platinum group metal and a support. In some embodiments, the selective HT catalyst includes Pd—Mo—Sn/ZrO₂.

The primary HT catalyst and/or the selective HT catalyst can be essentially free of sulfur. The term “essentially free of” as used herein refer to a material (e.g., sulfur) that is less than 1% by weight, less than 0.1% by weight, or even less than 0.01% by weight in a composition (e.g., a catalyst).

The methods disclosed herein include a primary hydrotreating (HT) reactor. Primary HT reactors are vessels configured to contain and expose the primary feed stream to hydrogen in the presence of a primary HT catalyst to produce an aromatic product. In some embodiments, the primary HT reactor may be a conventional fixed bed reactor containing a bed of at least one primary HT catalyst. Primary HT reactors may be configured to operate at weight hour space velocities (WHSV), temperatures, pressures, and flow rates of hydrogen gas to produce an aromatic product. In some embodiments, the primary HT reactor may operate with a WHSV of about 3 hr⁻¹.

The primary HT reactor may operate at a primary HT reactor temperature. The primary HT reactor temperature may range from 200 to 450° C., from 225 to 400° C., from 250 to 375° C., from 275 to 375° C., or from 300 to 350° C. The primary HT reactor may operate at a primary HT reactor pressure. The primary HT reactor pressure may be about 400 psig, about 450 psig, about 500 psig, about 550 psig, about 575 psig, about 585 psig, about 600 psig, about 615 psig, about 625 psig, about 650 psig, about 675 psig, about 700 psig. The primary HT reactor may operate at a primary HT reactor liquid hourly space velocity (LHSV). The primary HT reactor LHSV may range from about 0.5 hr⁻¹ to about 3.5 hr⁻¹, from about 0.75 hr⁻¹ to about 3.0 hr⁻¹, from about 1.25 hr⁻¹ to about 3.5 hr⁻¹, from about 1.75 hr⁻¹ to about 2.25 hr⁻¹, from about 1.90 hr⁻¹ to about 2.15 hr⁻¹, from about 1.0 hr⁻¹ to about 2.50 hr⁻¹. The primary HT reactor may operate at a primary HT hydrogen flow rate. The primary HT reactor hydrogen flow rate may range from 1000 scfb (standard cubic feet per barrel) to about 4000 scfb, from about 1250 scfb to about 3500 scfb, from about 1500 scfb to about 3250 scfb, from about 1750 scfb to about 3000 scfb, from about 2000 scfb to about 2750 scfb, or from about 2250 scfb to about 2650 scfb.

The methods disclosed herein can include reacting a crude feed stream with hydrogen in the presence of a selective hydrotreating (HT) catalyst in a selective HT reactor. Selective HT reactors are vessels configured to contain and expose the crude feed stream to hydrogen in the presence of a selective HT catalyst to produce a primary feed stream. Selective HT reactors may be configured to operate at weight hour space velocities (WHSV), temperatures, pressures, and flow rates of hydrogen gas to produce the primary feed stream. Relative to the primary HT reactor, the selective HT reactor may operate at a higher WHSV, lower temperatures, and with significantly lower H₂ flow rates than the primary HT reactor. In some embodiments, the selective HT reactor may operate with a WHSV from about 2 hr⁻¹ to about 20 hr⁻¹, from about 3 hr⁻¹ to about 15 hr⁻¹, from about 4 hr⁻¹ to about 10 hr⁻¹, from about 5 hr⁻¹ to about 8 hr⁻¹. In some embodiments, the selective HT reactor may operate with a WHSV of about 6 hr⁻¹. In some embodiments, the selective hydrotreating reactor is a selective hydrogenation unit (SHU) reactor. In some embodiments, the SHU reactor is a conventional fixed bed reactor containing a bed of at least one selective HT catalyst. An example of a commercially available SHU reactor includes Prime-G+ (Axens, Rueil-Malmaison, France). Notably, Prime-G+ utilizes sulfided selective HT catalysts. In some embodiments, the selective HT reactor may operate with a flow of hydrogen. In some embodiments, the selective HT reactor may operate using dissolved hydrogen in one or more feed streams to the selective HT reactor.

The selective HT reactor may operate at a selective HT reactor temperature. The selective HT reactor temperature may range from 100 to 250° C., from 115 to 225° C., from 130 to 200° C., or from 145 to 175° C. The selective HT reactor may operate at a selective HT reactor pressure. The selective HT reactor pressure may range from about 50 psig to about 700 psig, about 100 psig to about 700 psig, about 150 psig to about 700 psig, about 200 psig to about 700 psig, about 250 psig to about 700 psig, about 300 psig to about 700 psig, about 350 psig to about 700 psig, about 400 psig to about 700 psig, about 450 psig to about 700 psig, about 500 psig to about 700 psig, from about 550 psig to about 675 psig, from about 575 psig to about 650 psig, from about 600 psig to about 625 psig. The selective HT reactor may operate at a selective HT reactor liquid hourly space velocity (LHSV). The selective HT reactor LHSV may range from about 0.5 hr⁻¹ to about 6.5 hr⁻¹, from about 0.75 hr⁻¹ to about 5.0 hr⁻¹, from about 2.25 hr⁻¹ to about 5.5 hr⁻¹, from about 3.75 hr⁻¹ to about 5.25 hr⁻¹, from about 4.25 hr⁻¹ to about 4.75 hr⁻¹. The selective HT reactor may operate at a selective HT hydrogen flow rate. The selective HT reactor hydrogen flow rate may range from about 10 scfb to about 4000 scfb, from about 25 scfb to about 4000 scfb, from about 35 scfb to about 3500 scfb, from about 50 scfb to about 3500 scfb, from 75 scfb to about 4000 scfb, from about 85 scfb to about 3500 scfb, from about 100 scfb to about 4000 scfb, from about 250 scfb to about 3500 scfb, about 1000 scfb to about 4000 scfb, from about 1250 scfb to about 3500 scfb, from about 1500 scfb to about 3250 scfb, from about 1750 scfb to about 3000 scfb, from about 2000 scfb to about 2750 scfb, or from about 2250 scfb to about 2650 scfb.

Systems

Referring to FIG. 1, the systems disclosed herein may include a selective hydrotreating (HT) reactor (201) comprising a selective HT catalyst and a first inlet configured to receive a crude feed stream (200), the selective HT reactor (201) configured to react the crude feed stream (200) with hydrogen in the presence of the selective HT catalyst to produce a primary feed stream (100); and a primary HT reactor (101) comprising a primary HT catalyst and a second inlet configured to receive the primary feed stream (100) produced in the selective HT reactor (201), the primary HT reactor configured to react the primary feed stream (100) with hydrogen in the presence of the primary HT catalyst to produce the aromatic product (102).

The primary hydrotreating catalyst used in the present system can be essentially free of sulfur.

The systems disclosed herein can be configured to receive a crude feed stream. In some embodiments, the crude feed stream includes: (1) C₆₊ aromatic compounds, which comprise a C₁₀₊ polyaromatic compound and (2) C₂₊O₁₊ oxygenates. In some embodiments, at least one of (1) the C₁₀₊ polyaromatic compound and (2) the C₂₊O₁₊ oxygenates are reduced in the aromatic product relative to the crude feed stream. In some embodiments, the crude feed stream includes C₈₊ aromatic compounds. In some embodiments, the crude feed stream includes C_8-17 aromatic compounds. In some embodiments, the crude feed stream is narrow range synthetic aromatic kerosene (NRSAK), broad range synthetic aromatic kerosene (BRSAK), or combinations thereof.

Products

In another aspect, the present disclosure provides an aromatic product produced by the methods and/or systems as described herein. The aromatic product may include, for example, monoaromatics (e.g., about 75-95 wt %), naphthalenes (e.g., 1.5 wt % or less), cycloparaffins (e.g., about 5-25 wt %), and oxygenated hydrocarbons (e.g., 500 ppm or less).

In another aspect, the present disclosure provides an aromatic jet-range fuel product comprising the aromatic product produced by the systems and/or methods as described herein.

In another aspect, the present disclosure provides a sustainable aviation fuel (SAF) including the aromatic product produced by the systems and/or methods as described herein blended with a paraffinic sustainable fuel. The ratio of aromatic product to paraffinic sustainable fuel may be about 10:90 to about 30:70, including for example about 15:85, about 20:80, or about 25:75. Nonlimiting examples of the paraffinic sustainable fuel includes hydroprocessed esters fatty acids (HEFA), ethanol-to-jet material, and combinations thereof.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms. As used herein, the terms “include” and “including” have the same meaning as the terms “comprise” and “comprising.” The terms “comprise” and “comprising” should be interpreted as being “open” transitional terms that permit the inclusion of additional components further to those components recited in the claims. The terms “consist” and “consisting of” should be interpreted as being “closed” transitional terms that do not permit the inclusion of additional components other than the components recited in the claims. The term “consisting essentially of” should be interpreted to be partially closed and allowing the inclusion only of additional components that do not fundamentally alter the nature of the claimed subject matter. As used herein, the singular forms “a”, “an”, and “the” include plural embodiments unless the context clearly dictates otherwise. The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (for example, it includes at least the degree of error associated with the measurement of the particular quantity). The modifier “about” should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression “from about 2 to about 4” also discloses the range “from 2 to 4.” The term “about” may refer to plus or minus 10% of the indicated number. For example, “about 10%” may indicate a range of 9% to 11%, and “about 1” may mean from 0.9-1.1.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.

The present invention has been described in terms of one or more preferred embodiments, and it should be appreciated that many equivalents, alternatives, variations, and modifications, aside from those expressly stated, are possible and within the scope of the invention.

EXAMPLES

Example 1

Inventors identified platinum group metals (PGM) catalysts as likely candidates for hydrotreating the BRSAK fraction to remove oxygenates and partially saturate naphthalenes to tetralins. Target specifications include <1 wt % naphthalenes and <500 ppm oxygenates in the hydrotreated BRSAK product. Conditions would need to be found where both of these reactions were facile but monoaromatics are not saturated to cyclic paraffins, since this would decrease the value and/or utility of the SAK. Significant scoping work was conducted to identify such conditions. Promising results were obtained with a Pd/Al₂O₃ catalyst, with naphthalene content around 0.5 wt %, monoaromatic content around 85 wt %, and oxygenates <500 ppm. However, oxygenate breakthrough occurred after two weeks on stream (FIG. 2). This effect was reproducible over multiple runs, and other catalyst formulations also underwent a similar deactivation.

Since multiple catalysts demonstrated similar behavior, and activity can be recovered with an oxidative regeneration, the deactivation mechanism was, without wishing to be bound by theory, hypothesized to be coking of the catalyst, rather than an irreversible deactivation process. Dienes were identified as a potential culprit. In the petrochemical industry, a selective hydrotreater unit (SHU) is used upstream of the main hydrotreater to remove similar species that rapidly coke a catalyst. A typical SHU operates at a higher WHSV, lower temperatures, and with significantly lower H₂ rates than the primary hydrotreater.

To test the impact of using a SHU reactor upstream of the primary hydrotreater, a two-step system was developed. Untreated BRSAK was first sent to a SHU reactor under the following conditions: A PdMoSn/ZrO₂ catalyst, 150-170° C. reactor temperature, 600-625 psig, LHSV=4.5 hr⁻¹, H₂ rate 2400 scfb. The product from the SHU reactor was then fed forward to the primary hydrotreater, which operated under the following conditions: PtPd/Al₂O₃ catalyst, 300-350° C. reactor temperature, 600 psig, LHSV=2 hr⁻¹, H₂ rate 2400 scfb. Comparing the performance of this same catalyst when a SHU reactor is used upstream vs. when no SHU is used shows that inclusion of the SHU reactor provides a significant stability enhancement (FIG. 3). Without the SHU reactor, oxygenate breakthrough occurred after one week, while no oxygenate breakthrough was observed for over four weeks on stream when a SHU reactor was used. An average composition of untreated BRSAK feed, product of the SHU reactor, and product of the primary hydrotreater are shown in Table 1. On average, the SHU reactor consumed approximately 40 scfb H₂, and the primary HT reactor consumed approximately 390 scfb H₂. As can be seen in these results, the SHU reactor partially saturates some naphthalenes into monoaromatics and removes approximately 1500 ppm oxygenates. The primary reactor further saturates naphthalenes, reaching around 0.4 wt %, and removes oxygenates to the targeted <500 ppm value. Nearly 80 wt % of monoaromatics are retained in this product.

TABLE 1
Composition of untreated BRSAK feed, SHU product,
and primary HT product. Analyses were performed using
GC × GC and GC × SPE.

	Untreated		Primary
Description	BRSAK Feed	SHU Product	HT Product

Monoaromatics (wt %)	90.2	92.0	78.4
Naphthalenes (wt %)	3.3	0.9	0.4
Cycloparaffins (wt %)	5.5	6.3	20.5
Total Oxygenates (ppm)	29109	27664	165

For reasons of completeness, various aspects of the invention are set out in the following numbered clauses:

Clause 1. A method for producing an aromatic product, the method comprising:

• • feeding a primary feed stream into a primary hydrotreating (HT) reactor, the primary feed stream comprising (1) C₆₊ aromatic compounds, which include a C₁₀₊ polyaromatic compound and (2) C₂₊O₁₊ oxygenates;
  • feeding hydrogen into the primary HT reactor; and
  • reacting the primary feed stream with the hydrogen in the presence of a primary HT catalyst in the primary HT reactor to produce an aromatic product, at least one of (1) the C₁₀₊ polyaromatic compound and (2) the C₂₊O₁₊ oxygenates in the aromatic product being reduced relative to the primary feed stream, the primary HT catalyst being essentially free of sulfur.

Clause 2. The method of clause 1, further comprising:

• • reacting a crude feed stream with hydrogen in the presence of a selective HT catalyst in a selective HT reactor to produce the primary feed stream,
  • wherein the crude feed stream comprises: (1) the C₆₊ aromatic compounds, which comprise the C₁₀₊ polyaromatic compound and (2) the C₂₊O₁₊ oxygenates; and
  • wherein the C₁₀₊ polyaromatic compound is reduced in the primary feed stream relative to the crude feed stream.

Clause 3. A method for producing an aromatic product, the method comprising:

• • reacting a crude feed stream with hydrogen in the presence of a selective hydrotreating (HT) catalyst in a selective HT reactor to produce a primary feed stream, and
  • reacting the primary feed stream with hydrogen in the presence of a primary HT catalyst in a primary HT reactor to produce the aromatic product,
  • wherein the crude feed stream comprises: (1) C₆₊ aromatic compounds, which comprise a C₁₀₊ polyaromatic compound and (2) C₂₊O₁₊ oxygenates;
  • wherein at least one of (1) the C₁₀₊ polyaromatic compound and (2) the C₂₊O₁₊ oxygenates are reduced in the aromatic product relative to the crude feed stream.

Clause 4. The method of clause 3, wherein the primary HT catalyst is essentially free of sulfur.

Clause 5. The method of any one of clauses 3-4, wherein the C₁₀₊ polyaromatic compound is reduced in the primary feed stream relative to the crude feed stream.

Clause 6. The method of any one of clauses 1-5, wherein the primary HT catalyst comprises a platinum group metal.

Clause 7. The method of clause 6, wherein the primary HT catalyst comprises Pt—Pd/Al₂O₃.

Clause 8. The method of any one of clauses 2-7, wherein the selective HT catalyst is essentially free of sulfur.

Clause 9. The method of any one of clauses 2-8, wherein the selective HT catalyst comprises a platinum group metal.

Clause 10. The method of clause 9, wherein the selective HT catalyst comprises Pd—Mo—Sn/ZrO₂.

Clause 11. The method of any one of clauses 2-10, wherein the selective HT reactor is a selective hydrotreater unit (SHU).

Clause 12. The method of any one of clauses 1-11, wherein the C₁₀₊ polyaromatic compound is less than 0.5 wt % in the aromatic product.

Clause 13. The method of any one of clauses 1-12, wherein the C₂₊O₁₊ oxygenates are less than 500 ppm in the aromatic product.

Clause 14. The method of any one of clauses 1-13, wherein the C₂₊O₁₊ oxygenates in the aromatic product are maintained at less than 500 ppm for at least 10 days.

Clause 15. The method of any one of clauses 1-14, wherein the primary feed stream comprises at least 90 wt % C₆₊ aromatic compounds.

Clause 16. The method of any one of clauses 1-15, wherein the aromatic product comprises at least 80 wt % C₆₊ aromatic compounds.

Clause 17. The method of any one of clauses 1-16, wherein the primary feed stream comprises C₈₊ aromatic compounds.

Clause 18. The method of clause 17, wherein the primary feed stream comprises C_8-17 aromatic compounds.

Clause 19. The method of any one of clauses 2-16, wherein the crude feed stream comprises C₈₊ aromatic compounds.

Clause 20. The method of clause 19, wherein the crude feed stream comprises C_8-17 aromatic compounds.

Clause 21. An aromatic product produced by the method of any one of clauses 1-20.

Clause 22. An aromatic jet-range fuel product comprising the aromatic product of clause 21.

Clause 23. A sustainable aviation fuel (SAF) comprising the aromatic product of clause 21 blended with a paraffinic sustainable fuel.

Clause 24. The sustainable aviation fuel of clause 23, wherein the paraffinic sustainable fuel comprises hydroprocessed esters fatty acids (HEFA).

Clause 25. A system for producing an aromatic product, the system comprising:

• • a selective hydrotreating (HT) reactor comprising a selective HT catalyst and a first inlet configured to receive a crude feed stream, the selective HT reactor configured to react the crude feed stream with hydrogen in the presence of the selective HT catalyst to produce a primary feed stream; and
  • a primary HT reactor comprising a primary HT catalyst and a second inlet configured to receive the primary feed stream produced in the selective HT reactor, the primary HT reactor configured to react the primary feed stream with hydrogen in the presence of the primary HT catalyst to produce the aromatic product.

Clause 26. The system of clause 25, wherein the primary HT catalyst is essentially free of sulfur.

Clause 27. The system of any one of clauses 25-26, wherein the crude feed stream comprises: (1) C₆₊ aromatic compounds, which comprise a C₁₀₊ polyaromatic compound and (2) C₂₊O₁₊ oxygenates, and wherein at least one of (1) the C₁₀₊ polyaromatic compound and (2) the C₂₊O₁₊ oxygenates are reduced in the aromatic product relative to the crude feed stream.

Clause 28. The system of any one of clauses 25-27, wherein the crude feed stream comprises C₈₊ aromatic compounds.

Clause 29. The system of clause 28, wherein the crude feed stream comprises C_8-17 aromatic compounds.