Process and apparatus for hydrotreating alkane feedstock

Abstract

A process for hydrotreating a sustainable feedstock is disclosed. The process comprises hydrocracking a hydrocracking feed stream comprising greater than 90% alkanes in a hydrocracking reactor in the presence of hydrogen through a hydrocracking catalyst comprising one or more Group VIII metals and / or Group VIB metals to provide a hydrocracked stream. The hydrocracking reactor is operated at a temperature of from about 290 DEG C (550 DEG F) to about 450 DEG C (842 DEG F) and a pressure of from about 2.7 MPa (gauge pressure) (400 psig) to about 20.7 MPa (gauge pressure) (3000 psig). The hydrocracked stream is hydroisomerized in a hydroisomerization reactor in the presence of hydrogen via a hydroisomerization catalyst to provide a hydroisomerized stream. The hydroisomerized stream is separated to provide a jet fuel stream, a diesel stream, and an unconverted fuel stream.

Description

Technical Field

[0001] This field relates to a method for hydrogenating alkane-rich feedstocks. This field also relates to a method for hydrogenating sustainable feedstocks. Background Technology

[0002] With increasing global demand for fuels, there is growing interest in producing fuels and fuel blends from sources other than crude oil. These sources are often referred to as biorenewable sources and include, but are not limited to, vegetable oils such as corn oil, rapeseed oil, low-erucic acid rapeseed oil, and soybean oil; microbial oils such as algal oil; animal fats such as inedible tallow; fish oil; and various waste streams such as yellow and brown greases and sewage sludge. A common characteristic of these sources is that they consist of triglycerides and free fatty acids (FFAs). Both triglycerides and FFAs contain aliphatic carbon chains with approximately 8 to approximately 24 carbon atoms. The aliphatic carbon chains in triglycerides or FFAs can be fully saturated or mono, di, or polyunsaturated.

[0003] Hydrogenation can include methods of converting hydrocarbons into more valuable products in the presence of a hydrogenation catalyst and hydrogen. Hydrotreating is a method of contacting hydrocarbons with hydrogen in the presence of a hydrogenation catalyst, which is primarily used to remove heteroatoms such as sulfur, nitrogen, oxygen, and metals from hydrocarbon feedstocks. In hydrogenation, hydrocarbons with double and triple bonds, such as alkenes, can be saturated.

[0004] The production of hydrocarbon products within the boiling range of diesel can be achieved through hydrotreating biorenewable feedstocks. Hydrotreating can deoxygenate oxygenated hydrocarbons, including decarboxylation and decarbonylation. Following hydrotreating, hydroisomerization can be performed to improve the cold-flow properties of the resulting diesel and jet fuel. Hydroisomerization, or hydrodewaxing, is a hydrogenation process that increases alkyl branching on the hydrocarbon backbone in the presence of hydrogen and a hydroisomerization catalyst to improve the cold-flow properties of the hydrocarbon. Hydroisomerization includes the hydrodewaxing discussed herein.

[0005] Hydrocracking is a hydrogenation process in which hydrocarbons are cracked into lower molecular weight hydrocarbons in the presence of hydrogen and a hydrocracking catalyst. Depending on the desired output, a hydrocracking unit may contain one or more identical or different catalyst beds.

[0006] Sustainable technologies are being developed and commercialized to synthesize alkanes from sustainable or renewable carbon and hydrogen sources. However, the products of these alkane synthesis are generally unsuitable for the production of sustainable aviation fuel (SAF), diesel, and lubricants. The synthesis of these alkanes can produce alkanes with sufficiently high carbon numbers, which are problematic for meeting fuel specifications such as freezing point and pour point.

[0007] Existing technologies utilize hydrocracking catalysts and adjust the recycle fractionation point or unconverted oil fractionation point in the hydrocracking process to reduce the carbon number, increase the severity of hydrocracking, and thus increase the isomer content of the resulting product fuel stream.

[0008] The Fischer-Tropsch process has been widely used to facilitate hydrocarbon formation. As is generally known, the Fischer-Tropsch process converts hydrogen and carbon monoxide (often referred to as syngas) into liquid hydrocarbons, examples of which include hydrocarbons within the boiling range of naphtha, kerosene, diesel, and paraffin. As a preliminary step in Fischer-Tropsch synthesis, coal, gas, or biomass (such as biochar, municipal solid waste, crop or agricultural residues, forest residues, energy crops, wastewater sludge, sewage, etc.) is thermally gasified using heat and pressure to produce syngas, resulting in the conversion of feedstock into hydrogen and carbon monoxide. Another exemplary preliminary step can obtain carbon dioxide directly from sources of carbon dioxide emissions, such as combustion processes, carbonate calcination processes used in cement production, and catalyst regeneration processes, such as those from fluid catalytic cracking regenerators. Carbon dioxide can also be obtained directly from atmospheric air via direct air capture technology. Hydrogen, a component of syngas, can be obtained from the electrolysis of water or the pyrolysis of biomethane. The synthesis of hydrocarbons is very attractive from an environmental point of view because they are essentially alkanes and produce virtually no pollution, such as organic sulfur and organic nitrogen compounds.

[0009] As refineries seek to increase their capacity to process sustainable feedstocks, they are looking for ways to produce larger volumes of jet fuel due to its high value and demand. Methods for producing diesel fuel from sustainable feedstocks and increasing jet fuel production are needed. Furthermore, the production of very high-quality base oils from sustainable feedstocks that meet key lubricant performance requirements will be a growing market. Summary of the Invention

[0010] This method and apparatus produce a diesel feedstock from sustainable feedstock, including hydrotreating the feedstock to remove heteroatoms, hydrocracking to reduce the carbon number and provide jet fuel range materials, and hydroisomerization to improve cold flow characteristics. The disclosed method converts alkanes into sustainable distillates that meet fuel specifications such as freezing point, cloud point, and pour point, and also produces base oils suitable as lubricant components. This disclosure significantly mitigates the carbon number reduction effect of hydrocracking by using a single reaction stage for hydrocracking and hydroisomerization of the feedstock, thereby increasing the degree of isomerization and improving cold flow characteristics. Attached Figure Description

[0011] The attached figure is a simplified flow diagram of a method and apparatus for hydrogenating sustainable feedstocks according to the present disclosure.

[0012] definition

[0013] The term "connectivity" means that material flow is operatively permitted between enumerated components.

[0014] The term "downstream connectivity" means that in downstream connectivity at least a portion of the material flowing toward the main body can be operatively flowed from the object with which it is connected.

[0015] The term "upstream connectivity" means that at least a portion of the material flowing out of the main body in an upstream connectivity can be operatively flowed to the object connected to it.

[0016] The term "direct connection" means that the flow from the upstream component enters the downstream component without passing through fractionation or conversion units, and the composition does not change due to physical fractionation or chemical conversion.

[0017] The term "indirect connection" means that the flow from the upstream component enters the downstream component after passing through the fractionation or conversion unit, and the composition changes due to physical fractionation or chemical conversion.

[0018] The term "bypass" means that an object is disconnected from the downstream entity at least within the scope of the bypass.

[0019] The term "tower" refers to one or more distillation columns used to separate one or more components with different volatility. Unless otherwise specified, each column includes a condenser at the top of the column for condensing a portion of the overhead feed and refluxing it back to the top of the column, and a reboiler at the bottom of the column for vaporizing a portion of the bottom feed and returning it to the bottom of the column. The feed to the column can be preheated. The top pressure is the pressure of the vapor at the top of the column at the vapor outlet. The bottom temperature is the temperature at the bottom outlet of the liquid. Top and bottom lines refer to the net lines from any downstream reflux or reboiler to the column. A stripping column may omit the reboiler at the bottom of the column, instead providing the heating requirements and separation power for a liquefied inert medium such as steam. Stripping columns typically feed from the top tray and remove the main product from the bottom.

[0020] As used herein, the term "rich feed stream" means that the rich feed stream exiting the container has a higher component concentration than the feed entering the container.

[0021] As used herein, the term "lean component stream" means that the lean component stream exiting the container has a lower component concentration than the feed into the container.

[0022] As used herein, the term “boiling point temperature” refers to the atmospheric equivalent boiling point (AEBP) calculated from the observed boiling temperature and distillation pressure, such as using the formulas provided in ASTM D86 or ASTM D2887.

[0023] As used herein, the term “true boiling point” (TBP) refers to a test method conforming to ASTM D-2892 for determining the boiling point of a substance. ASTM D-2892 is used to produce standardized masses of liquefied gases, distillate fractions, and residues for which analytical data are available, and to determine the yield of the aforementioned fractions by both mass and volume, based on which a graph of distillation temperature versus mass% is obtained using fifteen theoretical plates in a column with a reflux ratio of 5:1.

[0024] As used herein, the terms “T5” or “T95” refer to the boiling temperature of a 5% or 95% mass percentage sample obtained using ASTM D-86 or TBP (as applicable).

[0025] As used in this article, the term “initial boiling point” (IBP) refers to the temperature at which a sample begins to boil using ASTM D2887, ASTM D-86, or TBP (as applicable).

[0026] As used herein, the term “endpoint” (EP) refers to the temperature at which a sample is brought to a complete boil using ASTM D2887, ASTM D-86, or TBP (as applicable).

[0027] As used herein, the term "jet fuel range material" refers to hydrocarbons that boil within an IBP range between about 85°C (185°F) and about 135°C (275°F) or between about 110°C (230°F) and about 160°C (320°F) using the TBP distillation method, and the "jet fractionation point" between jet fuel and diesel includes a T95 between about 295°C (563°F) and about 315°C (599°F). Hydrocarbons exceeding the "jet fractionation point" and reaching a "diesel fractionation point" including a T95 between about 343°C (650°F) and about 399°C (750°F) are "diesel boiling range" materials using the TBP distillation method. The "recycle fractionation point" can be either the jet fractionation point or the diesel fractionation point. Hydrocarbons boiling above their recycle fractionation point are typically unconverted hydrocarbons because they have not been converted to hydrocarbons boiling below their recycle fractionation point, which can also be considered the "conversion" fractionation point when using the TBP distillation method. Hydrocarbons below the jet range fuel material include naphtha and LPG.

[0028] As used herein, the term "conversion" refers to the ratio of products boiling below the recycle fractionation point to hydrocarbons boiling at or above the recycle fractionation point. Conversion can also be expressed as 100% of the feed minus the percentage of unconverted oil based on the feed.

[0029] As used herein, the term "separator" refers to a vessel having an inlet and at least one top vapor outlet and a bottom liquid outlet, and may also have an outlet for an aqueous feed stream from a boot. A flash tank is a type of separator that can be connected downstream to a separator capable of operating at higher pressures.

[0030] As used herein, the terms “major” or “most” mean greater than 50%, appropriately greater than 75%, and preferably greater than 90%.

[0031] As used in this article, the term "C" x "This should be understood as referring to a molecule having the number of carbon atoms indicated by the subscript "x". Similarly, the term "C" x "-" refers to a molecule containing less than or equal to x, and preferably x and fewer carbon atoms. The term "C" x "+" refers to a molecule having a number of carbon atoms greater than or equal to x, and preferably x and more.

[0032] As used in this article, the term "carbon number" refers to the number of carbon atoms in each hydrocarbon molecule, and typically in an alkane molecule. Detailed Implementation

[0033] This disclosure provides a method and apparatus for hydrogenating sustainable feedstocks. The method includes a single reaction stage for hydrocracking and hydroisomerization of the feedstream. Performing hydrocracking and hydroisomerization in a single stage saves money by reducing the number of required units and also produces jet fuel that meets specific cold flow requirements.

[0034] With increasing emphasis on environmental considerations, it is becoming increasingly attractive for refineries to produce low-carbon footprint or “green” fuels from Renewable Identifiers (RINs) accounted for under the Renewable Fuels Standard Procedure as part of their portfolios to maximize profitability. RINs are credits used for compliance and can be traded within the procedure to improve profitability. Utilizing carbon dioxide from carbon dioxide emission sources and reforming it into syngas also indirectly recycles carbon dioxide through Fischer-Tropsch synthesis. Direct utilization of carbon dioxide can generate associated incentives and other government incentives. This disclosure enables refineries to produce jet fuel that meets jet fuel specifications, while simultaneously increasing jet fuel yields.

[0035] The accompanying drawings, according to an exemplary embodiment, show a method and apparatus 101 for hydrogenating a sustainable feedstock. The sustainable feedstock may be a Fischer-Tropsch feedstock or a biorenewable feedstock. The method for hydrogenating the sustainable feedstock includes a hydrotreating section 111 and a hydrogenation section 131. A feed line 102 delivers a feed stream of fresh sustainable feedstock to the hydrotreating section 111. The sustainable feedstock may be blended with a mineral feed stream, but preferably comprises the primary or sole sustainable feedstock. The mineral feedstock is a conventional feedstock derived from crude oil extracted from underground sources.

[0036] Biorenewable feedstocks may have a nitrogen concentration of about 50 wppm to about 800 wppm. Biorenewable feedstocks may have a high oxygen content of up to 12% by weight. Biorenewable feedstocks may also contain sulfur of about 1 wppm to about 500 wppm, typically not exceeding about 200 wppm. A variety of different biorenewable feedstocks may be suitable for method 101. The term "biorenewable feedstock" is intended to include feedstocks other than those obtained from crude oil. Biorenewable feedstocks may include any of those feedstocks containing at least one of glycerides and free fatty acids. Most glycerides are triglycerides, but monoglycerides and diglycerides may also be present and processed. Free fatty acids may be obtained from phospholipids, which can provide phosphorus in the feedstock. Examples of these biorenewable raw materials include, but are not limited to, linseed oil, low-erucic acid rapeseed oil, corn oil, soybean oil, rapeseed oil, soybean oil, rapeseed oil, tallow, sunflower oil, hemp seed oil, olive oil, linseed oil, coconut oil, castor oil, peanut oil, palm oil, mustard oil, tallow, yellow and brown fats, lard, whale oil, fats from milk, fish oil, algae oil, sewage sludge, etc. Additional examples of biorenewable raw materials include non-edible vegetable oils from the group consisting of: Jatrophacurcas (Ratanjot, Wild Castor, Jangli Erandi), Madhuca indica (Mohuwa), Pongamia pinnata (Karanji, Honge), calophylluminophyllum, Moringa (moringa oleifera), and Azadirachta indica (Neem). Typical plant or animal fats, including triglycerides and FFAs, contain aliphatic hydrocarbon chains having about 8 to about 30 carbon atoms in their structures. As will be understood, biorenewable feedstocks may include one or more of the aforementioned examples. Biorenewable feedstocks may be pretreated to remove contaminants and filtered to remove solids.

[0037] Another source of sustainable raw materials comes from producing C1-C using the Fischer-Tropsch (FT) synthesis method.100 The Fischer-Tropsch method is particularly useful because the resulting alkane feedstock is relatively lacking in the organic sulfur and organic nitrogen components typically associated with the same petroleum-based fuels. Syngas used in the FT synthesis process can be generated from carbon dioxide emissions from sources such as fuel combustion, calcination of carbonates used in cement production, etc. Hydrogen for producing FT synthesis gas can be provided via steam methane reforming (SMR), partial oxidation (POX), autothermal reforming, and water electrolysis. The crude synthesis gas is treated in various steps of the scrubbing and protection units to produce a synthesis gas relatively free of sulfur and nitrogen components, suitable for the FT synthesis unit. The synthesis gas is then transferred to the FT reactor to produce hydrocarbons and water. FT synthesis catalysts and operating conditions can also be selected to significantly reduce the content of organic oxygenates and olefins. The FT synthesis process can produce hydrocarbons containing C1 to C2. 100 Product streams of n-alkanes. The FT synthesis method produces alkanes with varying carbon number distributions, and preferably n-alkanes with a partially normal distribution characterized by an α value. Operating the FT synthesis at different α values ​​can skew the median carbon number in the product FT liquid and wax streams. The FT synthesis method can produce n-alkanes and carbon numbers inconsistent with fuel specifications such as the freezing point of SAF, the cloud point of diesel, the distillation specifications of SAF and diesel, and the pour point of lubricants. In one example, the FT synthesis method can produce at least two liquid product streams. One stream may contain essentially n-alkanes boiling below the recycle fractionation point. The other stream may contain essentially n-alkanes boiling above the recycle fractionation point.

[0038] According to this disclosure, the sustainable feed stream in feed line 102 is an alkane-rich feed stream for method 101. The alkanes, and preferably n-alkanes, can be produced synthetically using sustainable or biorenewable sources. One such example is the hydrogenation treatment of *Nitzschia*, an elliptical algae, which will produce a product with 30% C₂. 20 n-Alkanes of n-alkanes abundance. Other triglycerides can be hydrogenated to produce n-alkanes. The continuous feed stream in feed line 102 may contain C1 to C2 alkanes obtained from the Fischer-Tropsch (FT) synthesis process. 100 n-Alkanes. C 19+ n-Alkanes will produce SAFs that exceed the final boiling and freezing point specifications.

[0039] In the disclosed methods and apparatus for hydrogenating sustainable feedstocks, alkanes, preferably n-alkanes, are processed in a single reaction stage of the hydrogenation process, which includes a hydrocracking zone followed by a hydroisomerization zone. In one aspect, a portion of the alkane may be fed into the hydrocracking zone, and a portion of the alkane may be fed into the hydroisomerization zone.

[0040] In the disclosed method and apparatus, the hydroisomerization severity is adjusted to meet the cold flow characteristics specifications of the resulting distillate fuel and unconverted oil streams. The hydroisomerization effluent is fractionated into product streams comprising SAF, diesel, and unconverted oil. The unconverted oil may be a base oil that meets lubricant properties such as pour point, Noack volatility, and absolute viscosity. The unconverted oil may contain higher carbon number isomerized alkanes that boil above their recycling fractionation point and can be recycled to the hydrocracking reaction zone.

[0041] The hydrocracking zone reduces the carbon number of alkanes to a level suitable for distillation specifications conforming to SAF and diesel fuel. The hydrocracking zone also reduces the carbon number of alkanes to lower the absolute viscosity of the resulting unconverted oil to a lower, preferred value conforming to base oil specifications. The hydrocracking zone effluent is connected upstream to the downstream hydroisomerization zone. The hydrocracking zone effluent undergoes hydroisomerization in the hydroisomerization zone. In one embodiment, the entire hydrocracking zone effluent undergoes hydroisomerization in the hydroisomerization zone.

[0042] In one embodiment, all of the alkanes are fed to the hydroisomerization zone. In another embodiment, the alkanes are fed entirely to the hydrocracking zone. The hydroisomerization zone may be directly downstream of the hydrocracking zone. Another feed component to the hydrocracking zone may include recycled oil from the hydroisomerization reaction zone as described above. In yet another embodiment, lower carbon number alkanes conforming to SAF and diesel distillation specifications are fed to the hydroisomerization zone, and higher carbon number alkanes not conforming to SAF and diesel distillation specifications are fed to the hydrocracking zone. Method and apparatus 101 eliminates the need for a separate hydroisomerization unit and its associated capital and operating costs.

[0043] Referring back to reference method and apparatus 101, a continuous feed stream in feed line 102 can flow from a feed buffer tank to a hydrotreating section 111. According to this disclosure, the hydrotreating section 111 may include a guard bed reactor 110 and a hydrotreating reactor 120. The continuous feed stream in feed line 102 may be combined with a hydrogen stream in line 103 to provide a combined continuous feed stream in line 104. The combined continuous feed stream in line 104 is then passed to the guard bed reactor 110. Alternatively, the continuous feed stream in feed line 102 and the hydrogen stream in line 103 may be passed separately to the guard bed reactor 110. In one aspect, the continuous feed stream in feed line 102 may include a heated continuous feed stream.

[0044] The guard bed temperature of the guard bed reactor 110 can be between about 246°C (475℉) and about 343°C (650℉) or between about 288°C (550℉) and about 304°C (580℉). The guard bed reactor 110 is operated low enough to prevent olefin polymerization in the feed stream, but high enough to promote olefin saturation, hydrodemetallization, hydrodeoxygenation (including hydrodecarbonylation and hydrodecarboxylation), hydrodesulfurization, and hydrodenitrification reactions.

[0045] The guard bed may contain a base metal on a support. Base metals that can be used in this process include non-precious metals, nickel, chromium, molybdenum, and tungsten. Other base metals that can be used include tin, indium, germanium, lead, cobalt, gallium, and zinc. The process may also use metal sulfides, wherein the metal in the metal sulfide is selected from one or more of the listed base metals. Sustainable feedstocks may be charged through a base metal catalyst at pressures from 1379 kPa (absolute) (200 psia) to 6895 kPa (absolute) (1000 psia). In another embodiment, the guard bed catalyst may contain a second metal, wherein the second metal includes one or more of the following metals: tin, indium, ruthenium, rhodium, rhenium, osmium, iridium, germanium, lead, cobalt, gallium, zinc, and thallium. A nickel-molybdenum catalyst on alumina may be a suitable catalyst in the guard bed reactor 110. Multiple guard beds may be included in the guard bed reactor 110, such as two, three, or more. A hydrogen quenching feed stream from the hydrogen quenching line 106 may be injected at an interbed location to control the exothermic temperature.

[0046] The contact feed stream is discharged from the guard bed reactor 110 via contact feed line 112. In the guard bed reactor 110, most of the hydrodemetallization and hydrodeoxygenation (including hydrodecarbonylation and hydrodecarboxylation) reactions occur along with some hydrodenitrogenation and hydrodesulfurization. Removed metals include alkali metals, alkaline earth metals, and phosphorus. The contact feed stream in line 112 can be transferred to the hydrotreatment reactor 120.

[0047] On one hand, the contacted continuous feed stream in line 112 may be heated to increase its temperature before being passed to the hydrotreatment reactor 120. The heated, contacted continuous feed stream is then fed into the hydrotreatment reactor 120 of the hydrotreatment reactor section 111.

[0048] In the hydrotreating reactor 120, under hydrotreating conditions, a heated, contacting sustainable feed stream in line 112 is brought into contact with a hydrotreating catalyst in the presence of hydrogen to saturate the olefins or unsaturated portions of the n-alkane chains in the sustainable feed. The hydrotreating catalyst also catalyzes hydrodeoxygenation reactions, including hydrodecarboxylation and hydrodecarbonylation reactions, to remove oxygen-containing functional groups from hydrocarbon molecules in the sustainable feed, which are converted into water and carbon oxides. The hydrotreating catalyst also catalyzes the hydrodesulfurization of organic sulfur and the hydrodenitrogenation of organic nitrogen in the sustainable feed. Essentially, the hydrotreating reaction removes heteroatoms from hydrocarbons and saturates the olefins in the feed stream.

[0049] The hydrotreating catalyst can be disposed in one, two, or more beds. The hydrotreating hydrogen quenching feed stream from the hydrotreating hydrogen quenching line 121 can be delivered at an inter-bed location within the hydrotreating reactor 120. In one exemplary embodiment, two hydrotreating catalyst beds are shown in the figures. However, the hydrotreating reactor 120 may include more than two catalyst beds or a single hydrotreating catalyst bed.

[0050] Hydrotreating catalysts may include nickel, nickel and molybdenum, or cobalt and molybdenum, dispersed on a high surface area support such as alumina. Other catalysts include one or more noble metals dispersed on a high surface area support. Non-limiting examples of noble metals include platinum and / or palladium dispersed on an alumina support such as γ-alumina. Suitable hydrotreating catalysts include BDO 200, BDO 300, or BDO 400, available from UOP LLC, Des Plaines, Illinois. The hydrotreating reaction temperature may range from about 343°C (650°F) to about 427°C (800°F), and preferably from about 349°C (690°F) to about 400°C (752°F). Typically, hydrotreating conditions involve pressures from about 700 kPa (100 psig) to about 21 MPa (3000 psig).

[0051] A hydrotreatment feed stream comprising a hydrocarbon fraction with a significant concentration of n-alkane is produced in the hydrotreatment line 122 of the hydrotreatment reactor 120 from the hydrotreatment reactor section 111. The concentration of oxygenated compounds in the hydrocarbon fraction is essentially zero, while the olefin concentration is significantly reduced relative to the contacting sustainable feed stream. The organic sulfur concentration in the hydrocarbon fraction does not exceed 500 W ppm, and the organic nitrogen concentration in the hydrocarbon fraction is less than 10 W ppm.

[0052] The hydrotreatment stream in hydrotreatment line 122 can be separated to provide a hydrotreatment vapor stream and a hydrotreatment liquid stream, the hydrotreatment liquid stream having a lower oxygen concentration than the continuous feed stream. In one aspect, the hydrotreatment stream in hydrotreatment line 122 can be passed to separation section 123 to provide a hydrotreatment vapor stream in line 124 and a hydrotreatment liquid stream in line 125, the hydrotreatment liquid stream having a lower oxygen concentration than the continuous feed stream 102. In one exemplary embodiment, separation section 123 may include a thermal separator, one or more additional separators, and / or a stripping tower. According to this disclosure, the hydrotreatment vapor stream in line 124 can be extracted and processed to provide one or more of the hydrogen stream in line 103, the hydrogen quenching stream in line 106, and the hydrotreatment hydrogen quenching stream in line 121. The liquid stream from separation section 123 can be recycled to hydrotreatment reactor 120.

[0053] Desired products (such as transportation fuels) can be recovered or separated from the hydrotreated liquid stream in line 125. However, the hydrotreated liquid stream in line 125 contains a high concentration of n-alkanes and will have poor cold flow characteristics. Therefore, to improve cold flow characteristics, the hydrotreated liquid stream in line 125 can be passed to a hydrotreating section 131. According to this disclosure, the hydrotreating section 131 includes a hydrocracking reactor and a hydroisomerization reactor. In the hydrotreating section 131, the hydrotreated liquid stream in line 125 can be contacted with a hydroisomerization catalyst under hydroisomerization conditions in the hydroisomerization reactor to hydroisomerize n-alkanes to branched alkanes. In one aspect, a sustainable feed stream having an acceptablely low concentration of organic oxygenates and low concentrations of other contaminants can bypass the hydrotreating section 111 and flow into the hydrotreated liquid stream in line 125 in optional line 113. The sustainable feed stream in line 113 may originate from an FT synthesis process operated under conditions that produce acceptable low levels of organic oxygenates, olefins, and other contaminants harmful to the catalyst in hydrogenation section 131. The sustainable feed stream in line 113 and the hydrotreated liquid stream in line 125 may be hydrogenated in hydrogenation section 131. In one embodiment, the stream in line 125 may comprise the hydrotreated liquid stream in line 125 and / or a bypassed sustainable feed stream in line 113. In another embodiment, the sustainable feed stream in line 113 may be the sole feed into hydrogenation section 131. A hydrogenation feed stream is provided in line 126, which may comprise either the hydrotreated liquid stream in line 125 or the sustainable feed stream in line 113, or both.

[0054] In one embodiment, the hydrocracking reactor 136 and the hydroisomerization reactor 137 may be located in a single vessel. In another embodiment, the hydrocracking reactor may be stacked on top of the hydroisomerization reactor. In one exemplary embodiment, the hydrogenation treatment section 131 includes a hydrogenation treatment reactor 130, which includes the hydrocracking reactor 136 and the hydroisomerization reactor 137. In another embodiment, the hydrocracking reactor 136 and the hydroisomerization reactor 137 may be located in separate vessels.

[0055] Typically, methods for producing jet fuel-range materials include separate reactors for the hydrogenation feed stream in a hydroisomerization line 126. In method 101, both the hydrocracking reactor 136 and the hydroisomerization reactor 137 are located in a single vessel 130. The hydrogenation feed stream in line 126 first contacts the hydrocracking catalyst and forms the hydrocracking effluent stream. The entire hydrocracking effluent stream from the hydrocracking reactor 136 is passed to the hydroisomerization reactor 137. The hydroisomerization reactor may be located below the hydrocracking reactor. Therefore, the hydrocracking effluent stream is not separated into gaseous and liquid streams, and only the liquid stream is fed into the hydroisomerization reactor 137. The entire hydrocracking effluent stream, containing both gaseous and liquid components, is passed to the hydroisomerization reactor 137.

[0056] The hydrotreating feed stream and hydrogen in line 126 are passed to hydrocracking reactor 136. In addition, a recycle stream, which may contain a recycled diesel feed stream or unconverted oil (UCO), may be passed together with the hydrotreating liquid feed stream to hydrotreating reactor 130 for hydrocracking.

[0057] The disclosed methods for a hydrocracking reactor 136 with a hydrocracking catalyst bed 138 and a hydroisomerization reactor 137 with a hydroisomerization catalyst bed 139 produce jet fuel conforming to jet fuel specifications according to ASTM D7566. Instead of sending the hydrocracking effluent to a separation section for gas removal and possible product fractionation before feeding the hydrocracking feedstream to the hydroisomerization reactor, method 101 charges the entire effluent from the hydrocracking reactor 136 into the hydroisomerization reactor 137 and adjusts the hydroisomerization severity to meet the cold flow characteristics specifications of the resulting distillate fuel and unconverted oil stream.

[0058] Referring to hydrogenation section 131, the hydrogenation feed stream in line 125, which contains the liquid feed stream from line 126 undergoing hydrogenation, is passed to hydrocracking reactor 136. In another embodiment, the hydrogenation feed stream in line 126 contains a stream of synthetic n-alkanes from the FT synthesis process, substantially above the recycle fractionation boiling point, from line 113. According to this disclosure, a recycle stream in line 177 is also passed to hydrocracking reactor 136. In one exemplary embodiment, the recycle stream in line 177 is a recycle UCO stream. The recycle UCO stream in line 177 is hydrocracking to provide a hydrocracking effluent stream. In an exemplary embodiment, the recycle UCO stream in line 177 is separated into a first recycle UCO stream in line 173 and a second recycle UCO stream in line 174. The first recirculated UCO feed stream in line 173 is fed together with the hydrotreating feed stream in line 126 to the hydrotreating reactor 130. The second recirculated UCO feed stream in line 174 can be separated into an interbed recirculated UCO feed stream in line 175 and a supplementary recirculated UCO feed stream in line 179. The interbed recirculated UCO feed stream in line 175 can be fed together with the hydrocracking effluent stream to the hydroisomerization reactor 137. The supplementary recirculated UCO feed stream in line 179 can be fed to the hydrocracking reactor 136. Alternatively, the entire second recirculated UCO feed stream in line 174 can be fed together with the hydrocracking effluent stream to the hydroisomerization reactor 137. In another aspect, the diesel feed stream in line 157 can also be fed to the hydrocracking reactor 136 or the hydroisomerization reactor 137, or both.

[0059] In one exemplary embodiment, the first recirculated feed stream in line 173 and the hydrogenation feed stream in line 126 are combined or mixed to provide the hydrogenation feed stream in line 127. In one embodiment, the hydrocracking reactor feed stream in line 128 is taken from the hydrogenation feed stream in line 127. The hydrocracking reactor feed stream in line 128 is passed to hydrocracking reactor 136. The hydrocracking hydrogen stream in line 141 is also passed to hydrocracking reactor 136. In one embodiment, the hydrocracking reactor feed stream in line 128 is combined with the hydrocracking hydrogen stream in line 141 to provide the combined hydrogenation feed stream in line 132. The combined hydrogenation feed stream in line 132 is passed to hydrocracking reactor 136.

[0060] In one embodiment, the hydrocracking reactor 136 includes a hydrocracking feed inlet 114 and a hydrocracking effluent outlet 115 for discharging the hydrocracking effluent stream. The hydrocracking reactor feed stream in line 128 or the combined hydrogenation process feed stream in line 132 can be fed into the hydrocracking reactor 136 through the feed inlet 114.

[0061] The hydrocracking reactor 136 may be a fixed-bed reactor, which may include single or multiple catalyst beds, and various combinations of hydrocracking catalysts in one or more vessels. The hydrocracking reactor 136 may operate in conventional continuous gas-phase, moving-bed, or fluidized-bed hydrogenation reactors. In the presence of a hydrocracking hydrogen feed stream, the hydrocracking reactor 136 hydrogenates the hydrotreated liquid feed stream in line 125 and the first recirculated UCO feed stream in line 173 via a hydrocracking catalyst to provide the hydrocracking feed stream.

[0062] The hydrocracking reactor 136 can be operated based on a partial conversion of more than about 30 vol% or at least about 90 vol% of the hydrocarbon feed based on the total conversion. The hydrocracking reactor 136 can be operated under mild hydrocracking conditions, which will provide a total conversion of about 20 vol% to about 60 vol%, preferably about 30 vol% to about 50 vol% of the product from the hydrocracking feed stream to the boiling point below the recycling fractionation point.

[0063] Hydrocracking catalysts may comprise amorphous silica-alumina or zeolite in a catalyst base combined with one or more Group VIII or Group VIB metal hydride components to selectively produce a balance of light diesel and jet fuel distillates. Alternatively, catalysts typically comprising any crystalline zeolite cracking base to which Group VIII metal hydride components are deposited may be suitable. Additional hydride components may be selected from Group VIB to be combined with the zeolite base.

[0064] Zeolites in cracking feedstocks are sometimes referred to in the art as molecular sieves and are typically composed of silica, alumina, and one or more exchangeable cations (such as sodium, magnesium, calcium, rare earth metals, etc.). They are also characterized by having relatively uniform crystal pores with diameters between about 4 angstroms and about 14 angstroms. Preferably, zeolites with a silica / alumina molar ratio between about 3 and about 12 are used, and more preferably, zeolites with a silica / alumina molar ratio greater than 12 are utilized. Suitable zeolites found in nature include, for example, mordenite, zeolite, flaky zeolite, magnesia-alkali zeolite, cycloid zeolite, chalcogenide, buergerianite, and octahedral zeolite. Suitable synthetic zeolites include, for example, B, X, Y, and L crystal types, such as synthetic octahedral zeolite and mordenite. Preferred zeolites are those with crystal pore sizes between about 8 angstroms and 12 angstroms, wherein the silica / alumina molar ratio is about 4 to 60. An example of a zeolite that falls into the preferred group is the synthetic Y molecular sieve.

[0065] Naturally occurring zeolites are typically found in sodium, alkaline earth metal, or mixed forms. Synthetic zeolites are almost always prepared in sodium form. In any case, for use as a cracking matrix, it is preferable that most or all of the original zeolite monovalent metals are ion-exchanged with polyvalent metals and / or with ammonium salts, followed by heating to decompose the ammonium ions associated with the zeolite, thereby leaving hydrogen ions and / or exchange sites at their locations, effectively removing cations through further water removal. This property of hydrogen, or "cation-removed" Y zeolite, is described more specifically in US 3,100,006.

[0066] Mixed multivalent metal-hydrogen zeolites can be prepared by exchanging ions with ammonium salts, followed by partial reverse exchange with multivalent metal salts, and then calcination. In some cases, such as in the synthesis of mordenite, the hydrogen form can be prepared by direct acid treatment of alkali metal zeolites. In one aspect, preferred cracking substrates are those based on an initial ion exchange capacity lacking at least about 10 wt% and preferably at least about 20 wt% of metal cations. In another aspect, a desirable and stable class of zeolites is those in which hydrogen ions satisfy an ion exchange capacity of at least 20 wt%.

[0067] The active metal used as the hydride component in the preferred hydrocracking catalyst of this disclosure is a Group VIII active metal, namely iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, and platinum. In addition to these metals, other promoters, including Group VIB metals such as molybdenum and tungsten, may be used in combination. The amount of hydride metal in the catalyst can vary over a wide range. Broadly speaking, any amount between about 0.05 wt% and about 30 wt% can be used. Regarding noble metals, it is generally preferred to use about 0.05 wt% to about 2 wt% of noble metals. Noble metals are preferably used as hydride metals on the hydrocracking catalyst to provide selectivity for jet fuels because hydrogen sulfide and ammonia, which could deactivate the noble metal catalyst, have been removed upstream of the process.

[0068] In one exemplary embodiment, the hydrocracking catalyst is a noble metal catalyst.

[0069] The method of incorporating metal hydrides involves contacting the base material with an aqueous solution containing a suitable compound of the desired metal, wherein the metal exists in the form of a cation. After adding one or more selected metal hydrides, the resulting catalyst powder is then filtered, dried, and pelletized as needed with added lubricants, binders, etc., and calcined in air at a temperature, for example, from about 371°C (700°F) to about 648°C (1200°F) to activate the catalyst and decompose ammonium ions. Alternatively, the base material component can be pelletized, and then the hydride component can be added and activated by calcination.

[0070] The catalysts described above can be used undiluted, or powdered catalysts can be mixed with other relatively less active catalysts, diluents, or binders such as alumina, silica gel, silica-alumina cogel, activated clay, etc., in a proportion ranging from about 5% to about 90% by weight and co-prepared into pellets. These diluents can be used as is, or they may contain a small proportion of added hydride metals, such as Group VIB and / or Group VIII metals. Additional metal-promoted hydrocracking catalysts can also be used in the methods of this disclosure, including, for example, aluminum phosphate molecular sieves, crystalline chromosilicates, and other crystalline silicates. Crystalline chromosilicates are described more fully in US 4,363,178.

[0071] By means of a method, hydrocracking conditions may include a temperature of about 290°C (550°F) to about 450°C (842°F), preferably 300°C (572°F) to about 432°C (810°F), a pressure of about 2.7 MPa (gauge pressure) (400 psig) to about 20.7 MPa (gauge pressure) (3000 psig), and a 0.4 hr -1 to less than approximately 20 hours -1LHSV, and approximately 255 Nm 3 / m 3 (1,500 scf / bbl) to approximately 2,527 Nm 3 / m 3 The hydrogen rate of the oil (15,000 scf / bbl). In another method, hydrocracking conditions may include a temperature preferably from about 316°C (600℉) to about 399°C (750℉), a pressure from about 4.1 MPa (gauge pressure) (600 psig) to about 10.3 MPa (gauge pressure) (1500 psig), and a 0.4hr... -1 to less than approximately 4 hours -1 LHSV, and approximately 255 Nm 3 / m 3 (1,500 scf / bbl) to approximately 2,527 Nm 3 / m 3 Hydrogen rate of oil (15,000 scf / bbl).

[0072] The hydrocracking feed stream can exit the hydrocracking reactor 136. In one embodiment, the hydrocracking feed stream is discharged from outlet 115 and transferred to the hydroisomerization reactor 137. In one embodiment, the hydrocracking feed stream can be fed directly into the hydroisomerization reactor 137. In another embodiment, the entire hydrocracking feed stream can be charged into the hydroisomerization reactor 137 without separating the hydrocracking feed stream into components retained from the hydroisomerization reactor 137. The hydroisomerization reactor 137 includes a hydroisomerization feed inlet 116 for transferring the hydroisomerization feed and / or hydrocracking feed stream to the hydroisomerization reactor 137, and a hydroisomerization effluent outlet 117 for discharging the hydroisomerization feed stream. The hydrocracking feed stream can be transferred to the hydroisomerization reactor 137 through the hydroisomerization feed inlet 116.

[0073] According to one aspect of this disclosure, a portion of the hydrogenation feed stream in line 127, which contains the liquid feed stream from line 125 undergoing hydrotreatment, can be taken out and passed to the hydroisomerization reactor 137 in line 129. In one exemplary embodiment, the hydrogenation feed stream in line 127 can be diverted to provide the hydrocracking reactor feed stream in line 128 and the hydroisomerization reactor feed stream in line 129, where treatment is performed. As shown in the figures, the hydroisomerization reactor feed stream in line 129 is passed together with the entire hydrocracking feed stream from the hydrocracking reactor 136 to the hydroisomerization reactor 137. In one aspect, the hydroisomerization reactor feed stream in line 129 can be passed to the hydroisomerization reactor 137 via the hydroisomerization feed inlet 116. The hydroisomerized hydrogen stream in line 133 can also be passed to the hydroisomerization reactor 137. Since the hydrocracking feed stream from hydrocracking reactor 136 contains hydrogen and the entire hydrocracking feed stream is passed to hydroisomerization reactor 137, the hydrogen feed stream in line 133 can be optional. Hydroisomerization can be performed on the hydrocracking feed stream and the hydroisomerization reactor feed stream in line 129 via a hydroisomerization catalyst in the presence of the hydroisomerization hydrogen feed stream. Hydroisomerization reactor 137 can be directly downstream of hydrocracking reactor 136. In one exemplary embodiment, hydroisomerization feed inlet 116 is directly downstream of hydrocracking effluent outlet 115.

[0074] According to this disclosure, it is optional to divert the hydrogenation feed stream in line 127, which contains the liquid feed stream for hydrotreatment in line 125, into the hydrocracking reactor feed stream in line 128 and the hydroisomerization reactor feed stream in line 129. The entire hydrogenation feed stream in line 127 may be transferred to the hydrocracking reactor 136 in the hydrocracking reactor feed stream in line 128. In another aspect, the entire hydrogenation feed stream in line 127 may be transferred to the hydroisomerization reactor 137 in the hydroisomerization reactor feed stream in line 129. In another aspect, at least some of the hydrogenation feed stream in line 127 is transferred to the hydrocracking reactor 136, and the remainder of the hydrogenation feed stream is transferred to the hydroisomerization reactor 137.

[0075] Hydroisomerization (including hydrodewaxing) of n-hydrocarbons in hydroisomerization reactor 137 can be accomplished via one or more hydroisomerization catalyst beds, and the hydroisomerization reactor can be operated in a co-current operation mode. Fixed bed, trickle bed downflow, or fixed bed liquid immersion upflow modes are all suitable. A quenching feed stream containing hydrogen can be supplied to hydroisomerization reactor 137 for interbed quenching.

[0076] Suitable hydroisomerization catalysts may comprise metals of Group VIII (IUPAC 8-10) of the periodic table and a support material. Suitable Group VIII metals include platinum and palladium, each of which may be used alone or in combination. Hydroisomerization catalysts may comprise non-noble metals that are insensitive to sulfur deactivation in acidic environments. Examples of suitable non-noble metals include Ni, Mo, Co, W, Mn, Cu, Zn, or Ru. Mixtures of hydride metals, such as Co / Mo, Ni / Mo, and Ni / W, may also be used. The amount of one or more hydride metals may range from 0.1% to 25% by weight, based on the catalyst weight. Methods for loading the metal onto the support material include, for example, impregnating the support material with a metal salt of the hydride component and heating. Catalyst support materials containing hydride metals may also be sulfided before use.

[0077] The support material can be amorphous or crystalline. Suitable support materials include amorphous alumina, amorphous silica-alumina, magnesium alkali zeolite, ALPO-31, SAPO-11, SAPO-31, SAPO-37, SAPO-41, SM-3, MgAPSO-31, FU-9, NU-10, NU-23, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-48, ZSM-50, ZSM-57, MeAPO-11, MeAPO- 31. MeAPO-41, MgAPSO-11, MgAPSO-31, MgAPSO-41, MgAPSO-46, ELAPO-11, ELAPO-31, ELAPO-41, ELAPO-11, ELAPO-31, ELAPO-11, ELAPO-31, ELAPO-41, zeolite, nepheline, pyroxene, zeolite in hydrogen form, mordenite in magnesium or calcium form, and calcite in magnesium or calcium form, each of which may be used alone or in combination. ALPO-31 is described in US4,310,440. SAPO-11, SAPO-31, SAPO-37, and SAPO-41 are described in US4,440,871. SM-3 is described in US4,943,424, US5,087,347, US5,158,665, and US5,208,005. MgAPSO is MeAPSO, an acronym for metallic aluminum phosphosilicate molecular sieves, where the metallic Me is magnesium (Mg). Suitable MgAPSO-31 catalysts include MgAPSO-31. MeAPSO is described in US 4,793,984, while MgAPSO is described in US 4,758,419. MgAPSO-31 is the preferred MgAPSO, where 31 refers to MgAPSO having a structural type of 31. Many natural zeolites initially having reduced pore size (such as magnesium alkali zeolite) can be converted to forms suitable for olefin skeletal isomerization to produce essentially hydrogen forms by ammonium ion exchange and calcination to remove the associated alkali or alkaline earth metals, as taught in US 4,795,623 and US 4,924,027. Other catalysts and conditions for skeletal isomerization are disclosed in US 5,510,306, US 5,082,956 and US 5,741,759. The hydroisomerization catalyst may also include a modifier selected from lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, terbium, and mixtures thereof, as described in US5,716,897 and US5,851,949.Other suitable support materials include ZSM-22, ZSM-23, and ZSM-35, which are described for dewaxing in US 5,246,566 and in the article “New Molecular Sieve Process for Lube Dewaxing by Wax Isomerization,” 2 Microporous Materials 439-449 (1994) by SJ Miller. US 5,444,032 and US 5,608,968 teach suitable bifunctional catalysts composed of amorphous silica-alumina gel and one or more metals belonging to Group VIIIA, and are effective for the hydroisomerization of long-chain n-alkanes containing more than 15 carbon atoms. US5,981,419 and US5,908,134 teach a suitable bifunctional catalyst comprising: (a) a porous crystalline material isomorphous to a β-zeolite selected from borosilicates (BOR-B) and borosilicates (Al-BOR-B), wherein the molar ratio of SiO2:Al2O3 is greater than 300:1; and (b) one or more metals belonging to Group VIIIA, selected from platinum and palladium, in an amount ranging from 0.05 wt% to 5 wt%. V. Calemma et al., Applied Catalysis A: Overview (App. Catal. A: Gen.), 190 (2000), 207 teach another suitable catalyst. Alumina or silica can be added to the support material.

[0078] In one exemplary embodiment, the hydroisomerization catalyst is a noble metal catalyst.

[0079] Hydroisomerization conditions typically include temperatures from about 290°C (550°F) to about 450°C (842°F) and pressures from about 2.7 MPa (gauge pressure) (400 psia) to about 20.7 MPa (gauge pressure) (3000 psia). In another embodiment, hydroisomerization conditions may include temperatures from about 150°C (302°F) to about 432°C (810°F) and pressures from about 1724 kPa (absolute) (250 psia) to about 13.8 MPa (absolute) (2000 psia).

[0080] The hydroisomerization feed stream from hydroisomerization reactor 137 in hydroisomerization line 134 is a branched-chain alkanes-rich stream. The hydroisomerization feed stream in hydroisomerization line 134 can be discharged from hydroisomerization outlet 117 of hydroisomerization reactor 137. The term "rich" means that the effluent stream has a higher concentration of branched-chain alkanes than the feed stream entering hydroisomerization reactor 137, and preferably contains more than 50% by mass of branched-chain alkanes in total alkane content. It is envisioned that the hydroisomerization effluent may contain 80%, 90%, or 95% by mass of branched-chain alkanes in total alkane content. The degree of branching is determined by the operating conditions of the hydroisomerization catalyst, such that the jet fuel range, diesel boiling range, and cold flow characteristics of the unconverted oil reach desired cold flow characteristic values, such as, but not limited to, freezing point, cloud point, and pour point.

[0081] In one exemplary embodiment, the hydrocracking reactor 136 and the hydroisomerization reactor 137 are stacked or located within a single vessel 130. In the stacked configuration of this disclosure, the hydrocracking reactor 136 is positioned above the hydroisomerization reactor 137. For the stacked configuration, the combined hydrogenation feed stream in line 132 is passed to the hydrocracking reactor 136. The hydrocracking feed stream is extracted from the bottom of the hydrocracking reactor 136 and passed to the hydroisomerization reactor 137. The hydroisomerization feed stream in the hydroisomerization line 134 is extracted from the bottom of the hydroisomerization reactor 137.

[0082] The hydroisomerized feed from hydroisomerization reactor 137 in hydroisomerization line 134 can flow to a stripping column. In one exemplary embodiment, the hydroisomerized feed in line 134 is separated into vapor and liquid components in product separation section 161. Product separation section 161 may include a thermal separator 148, a cold separator 171, a hot flash drum 165, a cold flash tank 191, a hydroisomerization stripping column 140, and a product distillation column 150.

[0083] The hydroisomerized feed stream in line 134 is passed to thermal separator 148. In one aspect, the hydroisomerized feed stream in line 134 may pass through one or more coolers before being passed to thermal separator 148. Thermal separator 148 separates the hydroisomerized feed stream in line 134 into a first vapor stream in thermal separator top line 163 and a first liquid hydrocarbon stream in thermal separator bottom line 164. The first liquid hydrocarbon stream in line 164 may be passed to flash tank 165. Flash tank bottom stream in line 167 and flash tank top stream in line 166 are extracted from flash tank 165.

[0084] The first vapor stream in line 163 can be passed to cold separator 171 to provide the vapor cold separator overhead stream in line 176 and the liquid cold separator bottom stream in line 178. The first vapor stream in line 163 may pass through one or more coolers before being passed to cold separator 171. The aqueous stream may be drawn from the cold separator's reservoir in line 179. The liquid cold separator bottom stream in line 178 is passed to cold flash tank 191 and separated. The hot flash tank overhead stream in line 166 may also be passed to cold flash tank 191. In one aspect, the liquid cold separator bottom stream in line 178 and the hot flash tank overhead stream in line 166 may be combined to provide a combined stream, which is passed to cold flash tank 191. The flash tank bottom stream from line 194 and the flash tank top stream from line 193 are drawn from flash tank 191. An aqueous stream can be drawn from the flash tank's storage tank in line 169. The flash tank bottom stream from line 194 and the hot flash tank bottom stream from line 167 can be passed to the hydroisomerization stripping tower 140. In one embodiment, the flash tank bottom stream from line 194 and the hot flash tank bottom stream from line 167 can be combined to provide a combined bottom stream in line 168. The combined bottom stream in line 168 is then passed to the hydroisomerization stripping tower 140. Alternatively, the flash tank bottom stream from line 194 and the hot flash tank bottom stream from line 167 can be passed to the hydroisomerization stripping tower 140 separately.

[0085] Returning to the reference cold separator 171, a portion of the vapor cold separator overhead stream in line 176 can be passed to the amine scrubbing tower 180, where it can be treated to remove hydrogen sulfide (H2S), carbon monoxide (CO), carbon dioxide (CO2), and ammonia (NH3) present in the vapor cold separator overhead stream in line 176. The lean amine stream in line 181 can be introduced into the amine scrubbing tower 180 to scrub the vapor cold separator overhead stream in line 176. An amine stream 187 rich in components containing CO, CO2, NH3, and H2S is drawn from the bottom of the amine scrubbing tower 180. In another embodiment, a portion of the cold separator overhead stream can be a wash stream. This wash stream can be further processed to recover hydrogen or used directly as a feed stream for syngas production. The hydrogen-containing overhead recirculation stream in line 182 can be drawn from the amine scrubbing tower 180. The overhead recirculated feed stream in line 182 can be passed to the hydrotreatment reactor section 111. The overhead recirculated feed stream in line 182 can be compressed by compressor 183 to provide a compressed overhead recirculated feed stream in line 184. In one embodiment, the compressed overhead recirculated feed stream in line 184 can be passed to the hydrotreatment reactor section 111. In one embodiment, the compressed overhead recirculated feed stream in line 184 can be separated into a first overhead recirculated feed stream in line 185 and a second overhead recirculated feed stream in line 186. The first overhead recirculated feed stream in line 185 can be recycled to the hydrogenation reactor 130. The second overhead recirculated feed stream in line 186 can be passed to the hydrotreatment section 110.

[0086] Returning to product separation section 161, the combined bottom streams from line 168 (cold flash tank bottom stream from line 194 and hot flash tank bottom stream from line 167) are separated in hydroisomerization stripping column 140 to provide hydroisomerization vapor stream in line 142 and hydroisomerization liquid stream 144. A suitable stripping medium from line 143 is also fed to hydroisomerization stripping column 140. An inert stripping medium, such as steam, from stripping medium line 143 can be used to strip light gases from the hydroisomerization stream in line 134. The hydroisomerization vapor stream containing light gases in line 142 is taken from the top of hydroisomerization stripping column 140.

[0087] The hydroisomerized liquid stream 144 is taken from the bottom of the hydroisomerization stripping column 140 and transferred to the product distillation column 150 to fractionate the product stream.

[0088] The product distillation column 150 can be reboiled to provide the heat required for distillation by heat exchange with a suitable heat flow or in a flame heater. Alternatively, a stripping medium such as steam can be used as an inert gas.

[0089] The product distillation column 150 provides a top gaseous stream of naphtha and vapor in top line 152 and a bottom liquid stream in bottom line 156. The top stream can be completely condensed and separated from water in a distillation receiver. The resulting condensate stream, containing naphtha-range hydrocarbons with fewer than nine carbon atoms, can be recycled back to the FT synthesis unit for reforming into syngas. In another embodiment, naphtha-range molecules can be used as a component in a renewable gasoline blend. In yet another embodiment, naphtha-range molecules can be used in another process unit, such as a steam cracker or a fluidized catalytic cracking unit, to produce renewable olefins.

[0090] The product stream can be taken from one side of the product distillation column 150. A side stream containing the jet fuel range material in line 154 can be taken from one side of the product distillation column 150. The jet fuel stream in line 154 will conform to ASTM D7566 jet fuel specifications. In one embodiment, the jet fuel range material in line 154 may conform to the flash point and distillation endpoint specifications of ASTM D7566.

[0091] Returning to product distillation column 150, the diesel fuel stream in line 155 is also separated. Product distillation column 150 can be operated at a bottom temperature between about 149°C (300°F) and about 399°C (750°F), preferably not exceeding about 371°C (700°F), and a top pressure of about 0.35 MPa (gauge pressure) (50 psig), preferably not exceeding about 0.14 MPa (gauge pressure) (20 psig).

[0092] A distillation column bottoms liquid stream containing unconverted oil (UCO) is extracted from distillation column bottoms line 156. The UCO stream in line 156 may have a viscosity of about 3 cst to about 12 cst, or about 4.5 cst to about 9 cst, and may contain heavy polynuclear aromatic hydrocarbons (HPNAs). HPNAs are polynuclear aromatic hydrocarbons (PNAs) having seven or more aromatic rings. HPNAs can affect the color of the lubricating oil base feedstock and can therefore be removed to very low levels acceptable to lubricating base oils. The UCO stream in line 156 may be passed to an adsorber 160 comprising an adsorbent bed to adsorb HPNAs to a concentration below 100 wppm. In one exemplary embodiment, adsorber 160 may contain activated carbon as an adsorbent. Activated carbon can be derived from various sources, including petroleum coke, coal, wood, and shells such as coconut shells, using carbonization and / or activation process steps. Activation can be achieved, for example, by thermal treatment in an atmosphere of carbon dioxide, water, and mixtures thereof, by chemical treatment steps, and combinations thereof. Suitable activated carbon is commercially available and can be obtained, for example, from Calgon Activated Corp. Compton, Calif., USA.

[0093] In adsorber 160, the UCO feed stream in line 156 is contacted with an adsorbent such as activated carbon under contact conditions to remove one or more HPNA compounds and produce an HPNA-depleted UCO feed stream in line 162. HPNA compounds can be removed from the heavy UCO feed stream by various mechanisms such as distillation, adsorption, reaction, and reactive adsorption with an adsorbent. The HPNA-depleted UCO feed stream has a lower HPNA concentration relative to the HPNA concentration of the heavy UCO feed stream. Contact conditions in adsorber 160 may include a temperature of about 100°C to about 300°C and a pressure of about 0.34 MPa (absolute) (50 psia) to about 1.7 MPa (absolute) (250 psia).

[0094] According to one exemplary embodiment, the UCO feed stream in line 156 can be split into a recirculated UCO feed stream in line 177 and an adsorber feed UCO feed stream in line 172. The adsorber feed UCO feed stream in line 172 is passed to adsorber 160 and contacted with the adsorbent as described above. The recirculated UCO feed stream in line 177 is recycled to the hydrogenation treatment reactor 130. The recirculated UCO feed stream in line 177 can be split into a first recirculated UCO feed stream in line 173 and a second recirculated UCO feed stream in line 174, and processed as described above. In one aspect, a portion of the diesel feed stream in line 155 can be introduced into the recirculated diesel feed stream in line 157 and recycled to the hydrocracking reactor 136 or the hydroisomerization reactor 137, or both. In another aspect, the recirculated diesel feed stream in line 157 can be combined with the first recirculated UCO feed stream in line 173 and the hydrogenation feed stream in line 126 and delivered to the hydrogenation reactor 130.

[0095] In method 101, the operating conditions of the hydroisomerization reactor 137 are selected to adjust the harshness of the hydrocracking effluent stream and the hydroisomerization of the recycled UCO, so that the resulting distillate fuel and unconverted oil streams meet cold flow characteristics specifications. The unconverted oil contains higher-carbon-number isomerized alkanes, which can be recycled to the hydrocracking reactor to produce lower-carbon-number isomerized alkanes that meet the distillation specifications of SAF and diesel. Method 101 produces SAF that meets ASTM D7566 specifications while avoiding the need for a separate hydroisomerization unit and the associated capital and operating expenses.

[0096] Any of the aforementioned pipelines, conduits, units, equipment, containers, surrounding environment, areas, or the like may be equipped with one or more monitoring components, including sensors, measuring devices, data acquisition devices, or data transmission devices. Signal, method, or condition measurements, as well as data from the monitoring components, can be used to monitor conditions within, around, and in connection with the method or equipment. Signals, measurements, and / or data generated or recorded by the monitoring components may be collected, processed, and / or transmitted through one or more networks or connections, which may be private or public, general or dedicated, direct or indirect, wired or wireless, encrypted or unencrypted, and / or combinations thereof; this specification is not intended to be limiting in this respect.

[0097] Signals, measurements, and / or data generated or recorded by monitoring components may be transmitted to one or more computing devices or systems. The computing devices or systems may include at least one processor and a memory storing computer-readable instructions that, when executed by the at least one processor, cause the one or more computing devices to perform a method that may include one or more steps. For example, one or more computing devices may be configured to receive data from one or more monitoring components related to at least one piece of equipment associated with the process. One or more computing devices or systems may be configured to analyze the data. Based on the data analysis, one or more computing devices or systems may be configured to determine one or more recommended adjustments to one or more parameters of one or more methods described herein. One or more computing devices or systems may be configured to transmit encrypted or unencrypted data that includes one or more recommended adjustments to one or more parameters of one or more methods described herein.

[0098] Example

[0099] Simulation studies were conducted. The fresh feed used in this method was a hydrocracking feed stream. The chemical and physical properties of the hydrocracking feed stream are listed in Table 1 below.

[0100] Table 1

[0101]

[0102] In the hydrocracking reaction section, a noble metal catalyst on an amorphous silica-alumina support is used to treat the hydrocracking feed stream. The hydrocracking reaction section is operated at elevated temperature and pressure in the presence of hydrogen to produce the hydrocracking feed stream. The entire hydrocracking feed stream is then transferred to the hydroisomerization reaction section. In the hydroisomerization reactor section, a noble metal catalyst on a SAPO-11 support is used to treat the hydrocracking feed stream. The hydroisomerization reactor section is operated at elevated temperature and pressure in the presence of hydrogen to produce the hydroisomerized feed stream. The hydroisomerized feed stream is separated into a hydrogenated vapor stream and a hydrogenated liquid stream. The hydrogenated liquid stream is distilled to produce a jet fuel range stream and a diesel boiling range stream that has not been converted into a jet fuel range stream. The diesel boiling range stream is then transferred to the hydrocracking reaction section. Operating conditions, catalysts, and jet fuel characteristics are listed in Table 2 below.

[0103] Table 2

[0104]

[0105] The results shown in Table 2 clearly demonstrate that the jet fuel range feed rate meets the ASTM D7566 specification for synthetic alkane kerosene.

[0106] Specific implementation plan

[0107] While the following description is presented in conjunction with specific embodiments, it should be understood that the description is intended to be illustrative and not to limit the scope of the foregoing description and the appended claims.

[0108] The first embodiment of this disclosure is a method for hydrogenating sustainable feedstocks, the method comprising, in the presence of hydrogen, hydrocracking a hydrocracking feed stream containing greater than 90% alkanes through a hydrocracking catalyst comprising one or more Group VIII metals and / or Group VIB metals to provide a hydrocracking feed stream, wherein the hydrocracking reactor is operated at a temperature of about 290°C (550°F) to about 450°C (842°F) and a pressure of about 2.7 MPa (gauge pressure) (400 psig). The process is operated at a pressure of approximately 20.7 MPa (gauge pressure) (3000 psig); and in the presence of hydrogen, the hydrocracking feed stream is hydroisomerized in a hydroisomerization reactor via a hydroisomerization catalyst selected from the group below to provide a hydroisomerization feed stream, wherein the hydroisomerization reactor is operated at a temperature of approximately 290°C (550°F) to approximately 450°C (842°F) and a pressure of approximately 2.7 MPa (gauge pressure) (400 psig) to approximately 20.7 MPa (gauge pressure) (3000 psig). Embodiments of this disclosure are any one or all of the embodiments described in the preceding embodiments to the first embodiment described in this paragraph. The embodiments further include hydrotreating a continuous feed stream in the presence of hydrogen using a hydrotreating catalyst in a hydrotreating reactor to hydrodeoxygenate the continuous feed stream to provide a hydrotreated feed stream; and removing the hydrocracking feed stream from the hydrotreated feed stream and transferring the hydrocracking feed stream to the hydrocracking reactor. Embodiments of this disclosure are any one or all of the embodiments described in the preceding embodiments to the first embodiment described in this paragraph. The embodiments further include removing a hydroisomerized feed stream from the hydrotreated feed stream and transferring the hydroisomerized feed stream to the hydroisomerization reactor. Embodiments of this disclosure are any one or all of the embodiments described in the preceding embodiments to the first embodiment described in this paragraph, wherein the hydrocracking reactor and the hydroisomerization reactor are located in a single vessel. Embodiments of this disclosure are any one or all of the embodiments described in the preceding embodiments to the first embodiment described in this paragraph, wherein the hydrocracking feed stream comprises more than 90% n-alkanes. Embodiments of this disclosure are any one or all of the embodiments described in the preceding embodiments to the first embodiment described in this paragraph, wherein the entire hydrocracking feed stream is passed to the hydroisomerization reactor. Embodiments of this disclosure are any one or all of the embodiments described in the preceding embodiments to the first embodiment described in this paragraph, wherein the hydrocracking reactor is located above the hydroisomerization reactor within the vessel.The embodiments of this disclosure are any one or all of the previous embodiments to the first embodiment in this paragraph, and the embodiments further include separating the hydroisomerized stream into a hydrogenated vapor stream and a hydrogenated liquid stream; and distilling the hydrogenated liquid stream to produce a jet fuel range stream, a diesel boiling range stream, and an unconverted oil stream. The embodiments of this disclosure are any one or all of the previous embodiments to the first embodiment in this paragraph, wherein distilling the hydrogenated liquid stream includes stripping the hydrogenated liquid stream in a stripper to provide a stripper overhead stream and a stripper bottom liquid stream; and distilling the stripper bottom liquid stream to produce the jet fuel range stream, the diesel boiling range stream, and the unconverted oil stream. Embodiments of this disclosure are any one or all of the embodiments described in the preceding embodiments to the first embodiment described in this paragraph, wherein the embodiments further include contacting the unconverted oil stream with an adsorbent to remove HPNA compounds having at least seven aromatic rings and providing a treated unconverted oil stream having no more than 100 wppm of aromatic rings. Embodiments of this disclosure are any one or all of the embodiments described in the preceding embodiments to the first embodiment described in this paragraph, wherein the embodiments further include removing a recirculated diesel boiling range feed stream from the diesel feed stream and passing the recirculated diesel feed stream to the hydrocracking reactor. Embodiments of this disclosure are any one or all of the embodiments described in the preceding embodiments to the first embodiment described in this paragraph, wherein the hydrocracking feed stream is taken from a synthetic alkane feed stream obtained from the Fischer-Tropsch synthesis process. Embodiments of this disclosure are any one or all of the embodiments described in the preceding embodiments to the first embodiment described in this paragraph, wherein the hydrocracking reactor is in approximately... to less than approximately The operation is carried out at the LHSV. Embodiments of this disclosure are one, any, or all of the embodiments described in the preceding embodiments to the first embodiment in this paragraph, wherein the hydroisomerization reactor operates at approximately... to less than approximately The operation is performed at the LHSV. Embodiments of this disclosure are any one or all of the preceding embodiments to the first embodiment in this paragraph, wherein the hydrocracking catalyst is a noble metal catalyst. Embodiments of this disclosure are any one or all of the preceding embodiments to the first embodiment in this paragraph, wherein the hydroisomerization catalyst is a noble metal catalyst.

[0109] A second embodiment of this disclosure is a method for hydrogenating a sustainable feedstock, the method comprising hydrogenating an alkane stream to provide a hydrotreated stream, the alkane stream comprising greater than 90% n-alkanes; and hydrocracking a hydrocracking feed stream taken from the hydrogenated stream in the presence of hydrogen through a hydrocracking catalyst comprising one or more Group VIII metals and / or Group VIB metals to provide a hydrocracking stream, wherein the hydrocracking reactor is operated at a temperature of about 290°C (550°F) to about 450°C (842°F) and about 2 The process involves operating at pressures from 0.7 MPa (gauge pressure) (400 psig) to about 20.7 MPa (gauge pressure) (3000 psig); and providing a hydroisomerization feed stream by hydroisomerizing the entire hydrocracking feed stream in the presence of hydrogen using a hydroisomerization catalyst selected from the group described below, wherein the hydroisomerization reactor operates at temperatures from about 290°C (550°F) to about 450°C (842°F) and pressures from about 2.7 MPa (gauge pressure) (400 psig) to about 20.7 MPa (gauge pressure) (3000 psig). Embodiments of this disclosure are any one or all of the embodiments described in the preceding to the second embodiments of this paragraph, wherein the alkane feed stream is derived from the Fischer-Tropsch synthesis process. Embodiments of this disclosure are any one or all of the embodiments described in the preceding to the second embodiments of this paragraph, wherein the alkane feed stream comprises more than 90% n-alkanes. Embodiments of this disclosure are any one or all of the embodiments described in the preceding to the second embodiments of this paragraph, wherein the entire feed stream of the hydrocracking reactor is transferred to the hydroisomerization reactor. Embodiments of this disclosure are any one or all of the embodiments described in the preceding to the second embodiments of this paragraph, wherein the hydrocracking reactor and the hydroisomerization reactor are located in a single vessel.

[0110] A third embodiment of this disclosure is an apparatus for hydrogenating sustainable feedstocks, the apparatus comprising a hydrocracking reactor having a hydrocracking feed inlet and a hydrocracking effluent outlet; and a hydroisomerization reactor having a hydroisomerization feed inlet and a hydroisomerization effluent outlet, wherein the hydroisomerization feed inlet is in direct downstream fluid communication with the hydrocracking effluent outlet. Embodiments of this disclosure are any one or all of the embodiments described in the preceding embodiments to the first embodiment described in this paragraph, wherein the hydrocracking reactor and the hydroisomerization reactor are located in a single vessel. Embodiments of this disclosure are any one or all of the embodiments described in the preceding embodiments to the third embodiment described in this paragraph, wherein the hydrocracking reactor is stacked on top of the hydroisomerization reactor.

[0111] Although no further detailed description has been provided, it is believed that those skilled in the art can make full use of this disclosure by employing the foregoing description and can readily identify the essential features of this disclosure without departing from the spirit and scope of the invention, and can make various changes and modifications to adapt it to various uses and situations. Therefore, the foregoing preferred specific embodiments should be understood as illustrative only and not as limiting the remainder of this disclosure in any way, and are intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

[0112] In the foregoing, all temperatures are expressed in degrees Celsius, and all portions and percentages are by weight unless otherwise specified.

Claims

1. A method for hydrogenating sustainable feedstocks, the method comprising: In a hydrocracking reactor, a hydrocracking feed stream containing more than 90% alkanes is provided by hydrocracking in the presence of hydrogen through a hydrocracking catalyst comprising one or more Group VIII metals and / or Group VIB metals, wherein the hydrocracking reactor is operated at a temperature of about 290°C (550°F) to about 450°C (842°F) and a pressure of about 2.7 MPa (gauge pressure) (400 psig) to about 20.7 MPa (gauge pressure) (3000 psig); and The hydrocracking feed stream is hydroisomerized in the presence of hydrogen via a hydroisomerization catalyst in a hydroisomerization reactor to provide a hydroisomerization feed stream, wherein the hydroisomerization reactor is operated at a temperature of about 290°C (550°F) to about 450°C (842°F) and a pressure of about 2.7 MPa (gauge pressure) (400 psig) to about 20.7 MPa (gauge pressure) (3000 psig).

2. The method according to claim 1, further comprising: In a hydrotreating reactor, a feed stream is hydrotreated by a hydrotreating catalyst in the presence of hydrogen to hydrodeoxygenate the continuous feed stream, thereby providing a hydrotreating stream; as well as The hydrocracking feed stream is removed from the hydrotreating feed stream and transferred to the hydrocracking reactor.

3. The method according to claim 2, further comprising: The feed stream to the hydroisomerization reactor is removed from the feed stream of the hydrotreatment process and transferred to the hydroisomerization reactor.

4. The method of claim 1, wherein the hydrocracking reactor and the hydroisomerization reactor are located in a single vessel.

5. The method according to claim 1, wherein the hydrocracking feed stream comprises more than 90% n-alkanes.

6. The method of claim 1, wherein the entire feed stream of the hydrocracking is transferred to the hydroisomerization reactor.

7. The method of claim 4, wherein the hydrocracking reactor is located above the hydroisomerization reactor in the vessel.

8. The method according to claim 1, further comprising: The hydroisomerized feed stream is separated into a hydrogenated vapor feed stream and a hydrogenated liquid feed stream; as well as Distillation of the hydrogenated liquid stream produces jet fuel range streams, diesel boiling range streams, and unconverted oil streams.

9. The method of claim 8, wherein distilling the hydrogenated liquid stream comprises: In a stripper, the hydrogenated liquid stream is stripped to provide a stripper overhead stream and a stripper bottom stream; as well as Distillation of the bottom liquid stream of the stripper column produces the jet fuel range stream, the diesel boiling range stream, and the unconverted oil stream.

10. The method of claim 1, further comprising contacting the unconverted oil stream with an adsorbent to remove HPNA compounds having at least seven aromatic rings and providing a treated unconverted oil stream having no more than 100 wppm of the HPNA compounds.

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