Process for hydrogenating olefins

Abstract

An integrated process for hydrogenating olefins is described in which a hydrogen stream is produced from the electrolysis of water. The water is obtained from a first reaction step in which a first feed stream containing oxygenated hydrocarbons is reacted to produce a first reaction product stream containing olefins and a second reaction product stream containing water. The second reaction product stream is electrolyzed to produce an electrolyzer product stream containing hydrogen. The hydrogen is used to hydrogenate the olefins. A paraffin stream can be obtained from the hydrogenation effluent.

Description

[Technical Field]

[0001] (Statement of priority) This application claims priority to U.S. Provisional Patent Application No. 63 / 411,693, filed September 30, 2022, which is incorporated herein in its entirety.

[0002] FIELD OF THE INVENTION The field is the hydrogenation of olefin-containing streams with hydrogen streams produced by the electrolysis of water. [Background technology]

[0003] Because of the high energy output required to power aircraft, jet fuel is one of the few petroleum fuels that cannot be easily substituted for electric motor systems. Jet fuel, as described in ASTM D1655, is composed of 75% paraffins and 25% aromatics. Synthetic hydrocarbons from sources including alcohol-to-jet (ATJ-SPK) and hydrothermal conversion of fatty acid esters (CHJ) can also be used as jet fuel, as described in ASTM D7566. These sources can have aromatic contents as low as 0.5% by weight. Significant incentives are currently available for green jet fuel in certain regions.

[0004] Ethanol is a bio-based alcohol that can be dehydrated to ethylene. Ethylene can be dimerized to olefins, such as C4, C6, and C8 olefins. Olefin oligomerization is a process that allows smaller olefins to be oligomerized to larger olefins. More specifically, olefins, including dimerized olefins, can be converted to distillates, including jet fuel and diesel range products. The oligomerized distillates can be saturated for use as transportation fuels with high stability.

[0005] Processes utilizing electrochemical cells for chemical conversions have also been described. Generally, electrochemical cells include an anode, a cathode, and an electrolyte. A catalyst can be disposed on the anode, on the cathode, and / or in the electrolyte to promote a desired chemical reaction. In operation, reactants or a solution containing the reactants are fed into the cell. A voltage (potential difference) is then applied between the anode and cathode to promote the desired electrochemical reaction. When water is the reactant and products including oxygen and hydrogen are produced, the reaction is often referred to as water splitting or electrolysis, and the reactor is referred to as an electrolyzer.

[0006] Therefore, there is a need for a method for the hydrogenation of olefins that enables the utilization of bio-derived feedstocks such as ethanol for use as a transportation fuel source. Summary of the Invention

[0007] The inventors have devised an integrated process for hydrogenating olefins in which a hydrogen stream is produced from the electrolysis of water. The water is obtained from a first reaction step in which a first feed stream is reacted to produce a first reaction product stream comprising olefins and a second reaction product stream comprising water, and the second reaction product stream is electrolyzed to produce an electrolyzer product stream comprising hydrogen. The paraffin stream can be obtained from the hydrodistillate. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic plan view of the method of the present disclosure.

[0009] definition The term "communication" means that fluid flow is operably permitted between the listed components, which may be characterized as "fluid communication."

[0010] The term "downstream communication" means that at least a portion of the fluid flowing to an object in downstream communication can operatively flow from the object in fluid communication.

[0011] The term "upstream communication" means that at least a portion of the fluid flowing from the object with which it is in upstream communication can operatively flow to the object with which it is in fluid communication.

[0012] The term "direct communication" means that fluid flow from an upstream component enters a downstream component without passing through any other intervening vessel.

[0013] The term "indirect communication" means that fluid flow from an upstream component enters a downstream component after passing through an intervening vessel.

[0014] As used herein, the terms "predominant," "predominantly," or "predominantly" mean more than 50%, suitably more than 75%, and preferably more than 90%.

[0015] The term "column" refers to a distillation column or columns for separating one or more components of different volatility. Unless otherwise indicated, each column includes a condenser at the top of the column for condensing and refluxing a portion of the overhead stream that returns to the top of the column, and a reboiler at the bottom of the column for vaporizing a portion of the bottom stream and returning it to the bottom of the column. The feed to the column may be preheated. The top pressure is the pressure of the overhead vapor at the vapor outlet of the column. The bottom temperature is the liquid bottom outlet temperature. The overhead and bottom lines refer to the net lines from column to column downstream of any reflux or reboil. A stripper column may omit the reboiler at the bottom of the column and instead provide the required heat and driving force for separation from a fluidized inert medium such as steam. A stripping column typically feeds the feed to the top tray and removes the main product from the bottom.

[0016] As used herein, the term "separator" means a vessel having an inlet and at least an overhead vapor outlet and a bottoms liquid outlet, and may also have an aqueous outlet from a boot. A flash drum is a type of separator that may be in downstream communication with a separator that may be operated at a higher pressure. As used herein, the term "boiling point temperature" means the atmospheric equivalent boiling point (AEBP) calculated from the observed boiling point and distillation pressure, calculated using the formula provided in ASTM D1160 Appendix A7, entitled "Practice for Converting Observed Vapor Temperatures to Atmospheric Equivalent Temperatures."

[0017] The term "unit" should be understood to refer to one or more process steps comprising a chemical conversion. At the heart of a unit are one or more catalytic reactors or separation vessels necessary to achieve the conversion. A unit may further include additional separation vessels containing fractionation column(s) for separating product streams. A unit may further include pretreatment steps for the chemical conversion. Collectively, a "unit" includes one or more reactors or separation vessels and separation and pretreatment steps, whether shown in a diagram or explicitly discussed herein.

[0018] As used herein, the terms "T5," "T90," or "T95" refer to the temperature at which 5 percent, 90 percent, or sometimes 95 percent by weight of a sample boils using ASTM D-86 or TBP, respectively.

[0019] As used herein, the term "initial boiling point" (IBP) means the temperature at which a sample begins to boil using ASTM D-7169, ASTM D-86, or TBP, as the case may be.

[0020] As used herein, the term "end point" (EP) means the temperature at which the sample has completely evaporated using ASTM D-7169, ASTM D-86, or TBP, as the case may be.

[0021] As used herein, the terms "diesel" and / or "distillate" refer to hydrocarbons boiling in the "diesel cut point" range, including an IBP of 125°C (257°F) to 175°C (347°F) or a T5 of 150°C (302°F) to 200°C (392°F), and a T95 of 343°C (650°F) to 399°C (750°F) using the TBP distillation method or a T90 of 280°C (536°F) to 340°C (644°F) using ASTM D-86. The terms "green diesel" or "green distillate" refer to diesel containing hydrocarbons not derived from fossil fuels.

[0022] As used herein, the term "jet fuel" means a hydrocarbon that boils in the range of 190°C (374°F) to 215°C (419°F) with a T10 between 290°C (554°F) and 310°C (590°F). The term "green jet fuel" means a jet fuel that contains hydrocarbons that do not originate from fossil fuels.

[0023] As used herein, "electrolyzer" is intended to refer to a device that includes a cathode (negative charge), an anode (positive charge), and a membrane. The overall system may also include pumps, vents, storage tanks, power sources, separators, and / or other components. Typically, these devices are used to drive electrochemical reactions, such as the electrolysis of water, within the cell stack of an electrolyzer unit. Electricity is applied across the membrane to the anode and cathode, which, in the case of water electrolysis, separates water into its component molecules, hydrogen (H) and oxygen (O).

[0024] The term "cathode" refers to the electrode through which conventional electrical current exits a polarized electrical device and through which electrons enter from an external source or external circuit connected to the cell. The reduction reaction occurs at the cathode.

[0025] The term "anode" refers to the electrode through which conventional electrical current enters a polarized electrical device and electrons flow out to the outside or to an external circuit connected to the cell. The oxidation reaction occurs at the anode. DETAILED DESCRIPTION OF THE INVENTION

[0026] The disclosed method includes providing a first feed stream comprising oxygenated hydrocarbons to a first reaction unit; reacting the first feed stream to produce a first reaction product stream comprising olefins and a second reaction product stream comprising water; electrolyzing the second reaction product stream to produce an electrolyzer product stream comprising hydrogen; providing the first hydrogenation feed stream comprising hydrogen and the second hydrogenation feed stream comprising olefins to a hydrogenation unit; and hydrogenating the second hydrogenation feed stream over a hydrogenation catalyst at hydrogenation reaction conditions to form a hydrogenation product stream comprising paraffins.

[0027] Referring again to the drawing of FIG. 1 , the first feed stream in line 12 to the first reaction unit 10 can include oxygenated hydrocarbons. The oxygenated hydrocarbons include ethanol, propanol, other alcohols, and / or triglycerides. Preferably, the oxygenated hydrocarbons have a biological source, such as fermentation, or are obtained from vegetable oils. In an exemplary embodiment, the first feed stream in line 12 can include ethanol. The first feed stream in line 12 can predominantly include ethanol. The first reaction unit 10 can include ethanol dehydration.

[0028] Dehydration converts ethanol to ethylene and water. Ethanol dehydration is a highly endothermic reaction. Steam may be added to the reactor to help control the endotherm, reduce coke deposition, and improve catalyst stability. The water recycle stream in line 17 may additionally include a portion of the mixed first feed stream in line 14. Unconverted ethanol may also be recycled in the recycle feed stream in line 15 to include a portion of the mixed first feed stream in line 14.

[0029] The combined first feed stream may be heated in one or more stages by a heat exchanger, a combustion heater, or a combination thereof. In an exemplary embodiment, a portion of the heat generated in the hydrogenation unit 50 is captured as high-temperature steam and used to help heat the first combined feed stream in line 14 to a temperature of about 400°C. Thus, the hydrogenation unit 50 and the first reaction unit 10 may be heat integrated. More than 10%, more than 25%, or more than 50% of the heat required for the reaction in the first reaction unit 10 may be provided via heat integration from the hydrogenation unit 50. A combustion heater may also help provide sufficient heat. The first combined feed stream may be further heated to a dehydration reaction temperature of 400°C to 550°C before passing over the dehydration catalyst at a pressure of 317 kPa (gauge) (45 psig) to 2068 kPa (gauge) (300 psig) or 345 kPa (50 psig) to 630 kPa (gauge) (90 psig). Acceptable pressures can be from 1379 kPa (200 psig) to 1724 kPa (250 psig).

[0030] In one embodiment, the ethanol dehydration catalyst can be an alumina-based catalyst. The dehydration catalyst may comprise substantially gamma alumina.

[0031] In another embodiment, the first reaction unit 10 can include hydrogenation. A suitable feedstream in line 12 to the hydrotreating unit can include triglycerides derived from vegetable oils. Renewable feedstocks that can be used in the present invention include any that contain glycerides and free fatty acids (FFA). Examples of these feedstocks include, but are not limited to, canola oil, corn oil, soybean oil, rapeseed oil, tall oil, sunflower oil, hempseed oil, olive oil, linseed oil, coconut oil, castor oil, peanut oil, palm oil, mustard oil, cottonseed oil, tallow, yellow and brown grease, lard, whale oil, milk fat, fish oil, algae oil, sewage sludge, cuphea oil, camelina oil, jatropha oil, curcas oil, babassu oil, palm kernel oil, crambe oil, and the like. Biorenewable is another term used to describe these feedstocks. Typical vegetable oil or animal fat glycerides, FFAs, and fatty acid alkyl esters contain aliphatic hydrocarbon chains with 8 to 24 carbon atoms in their structure, with the majority of the oils containing high concentrations of fatty acids with 16 and 18 carbon atoms. Mixtures or co-feeds of renewable feedstocks and fossil fuel-derived hydrocarbons can also be used as feedstocks. Other feedstock components that can be used as co-feed components, especially in combination with the feedstocks listed above, include used motor oil and industrial lubricants, used paraffin wax, liquids obtained from downstream liquefaction processes such as Fischer-Tropsch technology following gasification of coal, biomass, or natural gas, liquids obtained from thermal or chemical depolymerization of waste plastics such as polypropylene, high-density polyethylene, and low-density polyethylene, and other synthetic oils produced as by-products from petrochemical and chemical processes. Mixtures of the above feedstocks can also be used as co-feed components. One advantage of using co-feed components is that what has been considered waste from fossil fuel-based or other processes can be converted into valuable co-feed components for current processes.In this alternative embodiment, the first feed stream in line 12 may be contacted with a multifunctional catalyst or set of catalysts having hydrogenation, deoxygenation, isomerization, and selective hydrocracking functions to produce a reaction distillate comprising water, carbon oxides, light hydrocarbon gases, hydrogen, and paraffinic hydrocarbons. The water, carbon oxides, light hydrocarbon gases, and hydrogen are separated from the reaction distillate to produce a liquid stream comprising paraffinic hydrocarbons.

[0032] As described above, a multifunctional catalyst or set of catalysts provides deoxygenation, hydrogenation, isomerization, and selective hydrocracking functions. The deoxygenation and hydrogenation functions may be the same or separate active sites, and may include a noble metal, such as a platinum group metal, including, but not limited to, ruthenium, rhodium, palladium, platinum, and mixtures thereof, at levels ranging from 0.05 to 2.0 wt. % of the catalyst composite. Some catalysts may contain up to 10 wt. % platinum or palladium on carbon. Examples of other active sites that can be used to provide deoxygenation and hydrogenation functions are base metal sulfides, such as NiMo sulfide or NiW sulfide. Base metals are metals that oxidize when heated in air, and in addition to nickel, molybdenum, and tungsten, which may be catalyst components herein, other base metals include iron, lead, zinc, copper, tin, germanium, chromium, titanium, cobalt, rhenium, indium, gallium, uranium, dysprosium, thallium, and mixtures and compounds thereof. For isomerization and selective hydrocracking functions, the second portion of the catalytic composite may contain a zeolite with acid functional groups capable of catalyzing isomerization and selective hydrocracking reactions. The zeolite concentration may range from 1 to 99 wt. % of the catalytic composite, depending on the type of zeolite used and the operating conditions. In one embodiment, the zeolite has medium to large pores with 10-12 ring members, such as BEA, MOR, MFI, or FAU. In another embodiment, the functional groups are amorphous acid sites found in materials such as amorphous silica-alumina. In another embodiment, to maximize the accessibility of large triglyceride molecules to the catalytically active sites, a portion of the support may contain 150 m 2The catalyst has a large external surface area of ​​greater than 1 / g or large mesopores with an average pore size greater than 45 Å. A highly porous structure with large openings is beneficial because it reduces diffusion problems that can prevent large glyceride molecules from accessing the catalyst's active sites. Furthermore, the large pores prevent diffusion resistance for the flight-range paraffins produced in this catalytic process, leading to further cracking into lower-value lighter products. An example of a catalyst or catalyst set that successfully catalyzes deoxygenation, hydrogenation, isomerization, and selective hydrocracking reactions in the same reaction zone is platinum dispersed on a support containing Y-zeolite. Another example is platinum and palladium on a support containing Y-zeolite bound to amorphous silica-alumina. An example of a catalyst set is sulfided NiMo supported on amorphous silica-alumina and platinum supported on amorphous silica-alumina.

[0033] The inlet temperature of the catalyst bed in the first reaction unit 10 in this embodiment can range from 150°C to 454°C (300°F to 850°F), and the inlet pressure should be greater than 1379 kPa gauge to 13790 kPa gauge (200 to 2000 psig). The feed stream is mixed with sufficient hydrogen to provide a hydrogen circulation rate of 168 to 1684 nL / L (1000 to 10,000 standard cubic feet per barrel, hereinafter SCFB) and passed into a reactor containing a catalyst or set of catalysts. Hydrogen can be obtained primarily from a recycle gas stream, which may have passed through a purification facility to remove acid gases. Fresh hydrogen can also be delivered from the first electrolysis product stream. The hydrogen-rich gas mixed with the feedstock, and any recycle stream containing hydrocarbons in one embodiment, contains at least 90 mole percent hydrogen. The feed rate, in liquid hourly space velocity (LHSV), is typically 0.3 to 5 hr -1 In one embodiment, an LHSV of less than 1.2 is used.

[0034] The first reaction unit 10 may produce multiple product streams after reaction of the first feed stream. These may include a recycle feed stream in line 15, a first reaction product stream in line 16, and a second reaction product stream in line 18. Additional streams may be produced. A light gas stream and / or a heavy olefin stream may be produced. The first reaction product stream in line 16 may comprise olefins. The second reaction product stream in line 18 may comprise water, preferably predominantly water. The second reaction product stream in line 18 may be sent to a surge tank 19 for accumulation of sufficient product or to be treated and / or purified before further processing.

[0035] When the first reaction unit comprises ethanol dehydration, the first reaction product stream in line 16 may comprise ethylene or may comprise predominantly ethylene. The first reaction product stream in line 16 may exit first reaction unit 10 at a pressure of between 317 kPa (gauge) (45 psig) and 630 kPa (gauge) (90 psig) or between 345 kPa (gauge) (50 psig) and 414 kPa (gauge) (60 psig). The first reaction product stream may be compressed using one or more compression stages prior to further reaction in second reaction unit 30. The first stage compressor may compress the first reaction product stream to a first pressure of between 350 kPa (gauge) (50 psig) and 1225 kPa (gauge) (175 psig). The second stage compressor may compress the first reaction product stream to a second pressure of between 455 kPa (gauge) (165 psig) and 3220 kPa (gauge) (460 psig). The third stage compression may compress the first reaction product stream to a third pressure of between 5.6 MPaG (800 psig) and 8.4 MPaG (1200 psig).

[0036] In one embodiment, a second reaction product stream comprising water may be produced after one or more compression stages. Preferably, the second reaction product stream is in a liquid phase. The second reaction product stream in line 18 may be fed to an electrolyzer unit 20 by electrolyzer feed line 22, either directly or after passing through a surge tank 19. The electrolyzer unit includes an electrolyzer.

[0037] The electrolyzer unit 20 may include an electrolyzer catalyst. The electrolyzer catalyst may include platinum (Pt). The electrolyzer catalyst may include platinum supported on carbon. The loading of platinum on carbon may be 0.1 mg / cm. 2 ~1mg / cm 2 The electrolytic cell feed stream, which includes water from the second reaction product stream, can be further augmented to include an alkaline aqueous solution. Potassium hydroxide (KOH) can be a preferred component of the electrolytic cell feed stream due to its high conductivity. Other electrolytes, such as bicarbonates, sulfates, or chlorides (KHCO3, K2SO4, and KCl), can also be used. No electrolytes need be used. The concentration of KOH in the electrolytic cell feed stream can range from 0.1 M to 1.5 M. The current density in the electrolytic cell unit 20 can be related to the concentration of KOH in the electrolytic cell anode reactant, with higher current densities being achieved at higher KOH concentrations. The concentration of KOH in the electrolytic cell feed stream can range from 0.1 M to 1.5 M. A voltage of 1.5 V to 5 V can be applied between the anode and cathode in the electrolytic cell unit 20. Lower applied voltages are preferred. A voltage of less than 2 V can be applied between the electrolytic cell anode and electrolytic cell cathode.

[0038] The electrolyzer 20 converts water to hydrogen and oxygen. The first electrolysis product stream in line 26 can include hydrogen, preferably predominantly hydrogen. The first electrolysis product stream can include greater than 95% hydrogen, or greater than 98% hydrogen, or greater than 99% hydrogen. The first electrolysis product stream can include nearly 100% hydrogen, for example, 99.9% hydrogen. In one embodiment, the first electrolysis product stream in line 26 is at a temperature of 40°C (104°F) to 120°C (248°F) and a pressure of 35 barg (508 psig) to 70 barg (1015 psig). The second electrolysis product stream in line 28 can include oxygen. The second electrolysis product stream can include predominantly oxygen. Oxygen is a valuable product and can be recovered for use as a feed to a fuel cell for power generation, for medical purposes, or for other industrial uses.

[0039] The process may further include reacting the first reaction product stream in line 16 in a second reaction unit 30 to produce a third reaction product stream in line 36 comprising olefins having a higher average molecular weight than the first reaction product stream in line 16. An exemplary process in second reaction unit 30 includes one or more oligomerization steps over one or more oligomerization catalysts in an oligomerization unit at oligomerization conditions to provide a third reaction product stream in line 36 comprising olefins.

[0040] The oligomerization may involve dimerizing an olefin stream containing ethylene, followed by further oligomerization of the ethylene dimers and ethylene oligomers. The resulting oligomers may be separated to provide a distillate stream, which may be saturated to provide a distillate fuel. The saturated stream may be recycled to the ethylene dimerization as a diluent to absorb the exotherm of the dimerization and / or oligomerization. Furthermore, to also manage the exotherm, the olefin stream in line 16 may be split and charged to two or more catalyst beds. The dimerization product of the catalyst bed, which may contain unconverted olefins, may also be sent to downstream beds, thereby increasing the overall conversion per pass. Furthermore, the dimerization product of the upstream catalyst bed serves as additional diluent to absorb the exotherm in the downstream catalyst bed.

[0041] The second reaction unit feed stream in line 16 may contain significant ethylene. The feed stream may contain predominantly ethylene. In one embodiment, the feed stream may contain at least 95 mole percent ethylene.

[0042] The second reaction unit feed stream in line 16 can be at a temperature of from 60°C (140°F) to 190°C (374°F), preferably from 100°C (212°F) to 170°C (338°F), and at a pressure of from 5.6MPag (800psig) to 8.4MPag (1200psig).

[0043] The second reaction unit 30 may include a dimerization reactor 32 and an oligomerization reactor 34. The dimerization reactor and the oligomerization reactor may be one reactor or multiple reactors. The second reaction unit feed stream may first be contacted with a dimerization catalyst to dimerize ethylene into dimers and then with an oligomerization catalyst to oligomerize the dimerized ethylene. The oligomerization catalyst may be located upstream of the dimerization catalyst.

[0044] The dimerization reaction takes 0.5 to 10 hours based on olefins. -1 At an LHSV of 1000 psi, the conversion may occur predominantly in the liquid phase or in a mixed gas-liquid phase. The inventors have found that a majority of the ethylene in the olefin stream is converted to higher olefins. Typically, at least 90-95 mole percent of the ethylene is dimerized across the dimerization catalyst bed. Ethylene is initially dimerized over the catalyst to butenes.

[0045] The dimerization catalyst may comprise a metal-supported catalyst. The dimerization catalyst is preferably an amorphous silica-alumina base with a metal from either Group VIII and / or Group VIB of the Periodic Table, using Chemical Abstracts Service notation. In one embodiment, the catalyst comprises a Group VIII metal promoted with a Group VIB metal. Typically, silica and alumina are present only in the base, so the silica to alumina ratio is the same for both the catalyst and the base. The metal may be impregnated onto the silica-alumina base or ion-exchanged into the silica-alumina base. Co-mulling is also contemplated. The catalyst of the present invention may have a low temperature acidity ratio of at least 0.15, suitably 0.2, and preferably greater than 0.25, as measured by ammonia temperature programmed desorption (TPD), as described below. Additionally, suitable catalysts have a low temperature acidity ratio of 50 to 400 m as determined by the nitrogen BET method. 2 / g of surface area.

[0046] A preferred dimerization catalyst is described below. The preferred dimerization catalyst comprises an amorphous silica-alumina support. One of the components of the catalyst support utilized in the present invention is alumina. The alumina can be any of various hydrous aluminum oxides or alumina gels, such as alpha-alumina monohydrate with a boehmite or pseudo-boehmite structure, alpha-alumina trihydrate with a gibbsite structure, or beta-alumina trihydrate with a bayerite structure. A particularly preferred alumina is available from Sasol North America Alumina Product Group under the Catapal trademark. This material is an extremely high-purity alpha-alumina monohydrate (pseudo-boehmite) that has been shown to yield high-purity gamma-alumina after calcination at high temperatures. Another component of the catalyst support is amorphous silica-alumina. A suitable silica-alumina having a silica to alumina ratio of 2.6 is available, for example, from CCIC, a subsidiary of JGC in Japan.

[0047] Another component utilized in the preparation of the catalyst utilized in the present invention is a surfactant. The surfactant is preferably mixed with the alumina and silica-alumina powders described above. The resulting surfactant, alumina, and silica-alumina mixture is then formed, dried, and calcined as described below. Calcination effectively removes the organic components of the surfactant by combustion, but only after the surfactant has faithfully performed its function in accordance with the present invention. Any suitable surfactant may be utilized in accordance with the present invention. A preferred surfactant is a surfactant selected from the series of commercially available surfactants sold by Solvay SA under the "Antarox" trademark. "Antarox" surfactants are generally characterized as modified linear aliphatic polyethers and are low-foaming biodegradable detergents and wetting agents.

[0048] A suitable silica-alumina mixture is prepared by mixing proportional volumes of silica-alumina and alumina to achieve the desired silica to alumina ratio. In embodiments, 75-95 wt. % amorphous silica-alumina having a silica to alumina ratio of 2.6 and 10-20 wt. % alumina powder provides a suitable support. In embodiments, other ratios of amorphous silica-alumina to alumina may be suitable.

[0049] Any convenient method can be used to incorporate the surfactant into the mixture of silica-alumina and alumina. The surfactant is preferably mixed during the mixing and formation of the alumina and silica-alumina. A preferred method is to mix an aqueous solution of the surfactant with the alumina and silica-alumina blend prior to final formation of the carrier. The surfactant is preferably present in the paste or dough in an amount of 0.01 to 10% by weight, based on the weight of the alumina and silica-alumina.

[0050] A monobasic acid such as nitric acid or formic acid can be added to the mixture in aqueous solution to peptize the alumina in the binder. Additional water can be added to the mixture to provide sufficient wettability to form a dough with sufficient consistency to be extruded or spray dried.

[0051] The paste or dough may be prepared in the form of shaped particles; a preferred method is to extrude a dough mixture of alumina, silica-alumina, surfactant, and water through a die having openings of the desired size and shape, after which the extruded material is divided into extrudates of the desired length and dried. A further calcination step may be used to provide additional strength to the extrudates. Typically, calcination is carried out in a stream of dry air at a temperature of 260°C (500°F) to 815°C (1500°F).

[0052] The extruded particles can have any suitable cross-sectional shape, i.e., symmetrical or asymmetrical, but most often have a symmetrical cross-sectional shape, preferably spherical, cylindrical, or multilobal. The cross-sectional diameter of the particles can be as small as 40 μm. However, it is usually between 0.635 mm (0.25 inch) and 12.7 mm (0.5 inch), preferably between 0.79 mm (1 / 32 inch) and 6.35 mm (0.25 inch), and most preferably between 0.06 mm (1 / 24 inch) and 4.23 mm (1 / 6 inch).

[0053] Typical properties of the amorphous silica-alumina supports utilized herein are total pore volume, average pore diameter, and a surface area large enough to provide substantial space and area for depositing the active metal components. The total pore volume of the support, as measured by conventional mercury porosimetry, is typically 0.2-2.0 cc / gram, preferably 0.25-1.0 cc / gram, and most preferably 0.3-0.9 cc / gram. Typically, the amount of pore volume of the support in pores with diameters greater than 100 angstroms is less than 0.1 cc / gram, preferably less than 0.08 cc / gram, and most preferably less than 0.05 cc / gram. Surface area, as measured by the BET method, is typically less than 50 m 2 / g or more, e.g. 200m 2 / g, preferably at least 250m 2 / gram, most preferably 300m 2 grams ~ 400m 2 / gram.

[0054] To prepare the catalyst, the support material is combined with one or more precursors of at least one metal component from Group VIII or Group VIB of the Periodic Table, such as by single or multiple impregnation of calcined amorphous refractory oxide support particles. The Group VIII metal, preferably nickel, should be present in a concentration of 0.5 to 15 wt. %, and the Group VIB metal, preferably tungsten, should be present in a concentration of 0 to 12 wt. %. Impregnation can be accomplished by any method known in the art, such as spray impregnation, in which a solution containing the metal precursors in dissolved form is sprayed onto the support particles. Another method is a multi-dip procedure, in which the support material is repeatedly contacted with the impregnation solution, with or without intermittent drying. Yet another method involves immersing or circulating the support in a large volume of the impregnation solution, and yet another method is the pore volume or pore saturation technique, in which the support particles are introduced into a volume of impregnation solution just sufficient to fill the pores of the support. In some cases, the pore saturation technique may be modified to utilize an impregnation solution having a volume between 10 percent less and 10 percent more than the volume that would just fill the pores.

[0055] If the active metal precursors are incorporated by impregnation, a subsequent or second calcination at elevated temperatures, for example, 399°C (750°F) to 760°C (1400°F), converts the metals to their respective oxide forms. Optionally, a calcination may be performed after each individual active metal impregnation. Subsequent calcinations result in a catalyst containing the active metals in their respective oxide forms.

[0056] A preferred dimerization catalyst of the present invention has an amorphous silica-alumina substrate impregnated with 0.5 to 15 wt. % nickel in the form of 3.175 mm (0.125 inch) extrudates and a density of 0.45 to 0.65 g / mL. It is also contemplated that the metal can be incorporated onto the support by other methods, such as ion exchange and co-mulling.

[0057] The dimerization catalyst can be regenerated upon deactivation. Suitable regeneration conditions include subjecting the catalyst, for example, in situ, to hot air at 500°C for 3 hours. To facilitate regeneration without downtime, a swing bed arrangement may be used with an alternative dimerization reactor. The regeneration gas may comprise air with increased or decreased oxygen concentration. The activity and selectivity of the regenerated catalyst are comparable to that of fresh catalyst.

[0058] To manage the heat release, the feed stream in line 16 may be diluted with a diluent stream to provide a dilute olefin stream to help absorb the heat release. The diluent stream may include a paraffin stream in diluent line 58. The first dilute olefin stream may include up to 25 wt.% olefins, suitably up to 10 wt.% olefins, and preferably up to 6 wt.% olefins. The first dilute olefin stream may include up to 25 wt.% ethylene, suitably up to 10 wt.% ethylene, and preferably up to 6 wt.% ethylene. A dimerization stream may be produced in line 33.

[0059] The second reaction unit 30 may further include an oligomerization reactor 34 .

[0060] The oligomerization reactor 34 may be in downstream communication with the dimerization reactor 32 via line 33. Alternatively, the oligomerization reactor 34 may be in upstream communication with the dimerization reactor 32. The oligomerization reactor 34 preferably operates in downflow operation. However, upflow operation may be preferred. The feed oligomerization stream is contacted with an oligomerization catalyst to dimerize and trimerize C2 to C8 olefins to provide distillate-range olefins. A majority of the butenes in the feed oligomerization stream are oligomerized. In embodiments, at least 99 mole percent of the butenes in the feed oligomerization stream are oligomerized. A third reaction product stream in line 36, having a higher average carbon number than the second reaction unit feed stream in line 16, exits the oligomerization reactor 34 and the second reaction unit 30 in line 36.

[0061] The oligomerization catalyst can include a zeolite catalyst. The zeolite can comprise 5 to 95 wt. % of the catalyst, e.g., 5 to 85 wt. %. Suitable zeolites include zeolites having a structure from one of the following classes: MFI, MEL, ITH, IMF, TUN, FER, BEA, FAU, BPH, MEI, MSE, MWW, UZM-8, MOR, OFF, MTW, TON, MTT, AFO, ATO, and AEL. Three-letter codes for zeotypes are as defined by the Structure Commission of the International Zeolite Association and maintained at http: / / www.iza-structure.org / databases. UZM-8 is as described in U.S. Pat. No. 6,756,030. In a preferred embodiment, the oligomerization catalyst can include a zeolite having a framework with a 10-ring pore structure. Examples of suitable zeolites having a 10-ring pore structure include TON, MTT, MFI, MEL, AFO, AEL, EUO, and FER. In a further preferred embodiment, the oligomerization catalyst comprising a zeolite having a 10-ring pore structure may comprise a one-dimensional pore structure. A one-dimensional pore structure refers to a zeolite containing non-intersecting pores that are substantially parallel to one of the crystal axes. The pores preferably extend throughout the zeolite crystal. A suitable example of a zeolite having a 10-ring one-dimensional pore structure may include MTT. In a further embodiment, the oligomerization catalyst comprises an MTT zeolite.

[0062] The oligomerization catalyst can be formed by combining a zeolite with a binder and then forming the catalyst into pellets. The pellets can optionally be treated with a phosphorus reagent to produce a zeolite having a phosphorus component of 0.5 to 15% by weight of the treated catalyst. The binder is used to impart hardness and strength to the catalyst. Binders include alumina, aluminum phosphate, silica, silica-alumina, zirconia, titania, and combinations of these metal oxides, as well as other refractory oxides and clays such as montmorillonite, kaolin, palygorskite, smectite, and attapulgite. Preferred binders are aluminum-based binders such as alumina, aluminum phosphate, silica-alumina, and clays.

[0063] One of the components of the catalyst binder utilized in the present invention is alumina. The alumina source can be any of a variety of hydrous aluminum oxides or alumina gels, such as alpha-alumina monohydrate with boehmite or pseudo-boehmite structure, alpha-alumina trihydrate with gibbsite structure, or beta-alumina trihydrate with bayerite structure. A suitable alumina is available from UOP LLC under the VERSAL trademark. A preferred alumina is available from Sasol North America Alumina Product Group under the Catapal trademark. This material is an extremely high purity alpha-alumina monohydrate (pseudo-boehmite) that has been shown to yield high purity gamma-alumina after high temperature calcination.

[0064] Suitable oligomerization catalysts are prepared by mixing proportional volumes of zeolite and alumina to achieve the desired zeolite to alumina ratio. In certain embodiments, the MTT content can be 5 to 85 wt. %, e.g., 20 to 82 wt. %, MTT zeolite, with the remainder being alumina powder to provide a suitably supported catalyst. Silica supports are also contemplated.

[0065] A monobasic acid such as nitric acid or formic acid may be added to the mixture in aqueous solution to peptize the alumina in the binder. Additional water may be added to the mixture to provide sufficient wettability to form a dough with sufficient consistency to be extruded or spray-dried. An extrusion aid such as cellulose ether powder may also be added. A preferred extrusion aid is available from The Dow Chemical Company under the Methocel trademark.

[0066] The paste or dough may be prepared in the form of shaped particles; a preferred method is to extrude the dough through a die having openings of the desired size and shape, followed by dividing the extruded material into extrudates of the desired length and drying. A further calcination step may be used to provide additional strength to the extrudates. Typically, calcination is carried out in a stream of air at a temperature of 260°C (500°F) to 815°C (1500°F). The MTT catalyst is not selective to neutralize acidic sites such as amines.

[0067] The extruded particles can have any suitable cross-sectional shape, i.e., symmetrical or asymmetrical, but most often have a symmetrical cross-sectional shape, preferably spherical, cylindrical, or multilobal. The cross-sectional diameter of the particles can be as small as 40 μm. However, it is usually between 0.635 mm (0.25 inch) and 12.7 mm (0.5 inch), preferably between 0.79 mm (1 / 32 inch) and 6.35 mm (0.25 inch), and most preferably between 0.06 mm (1 / 24 inch) and 4.23 mm (1 / 6 inch).

[0068] The oligomerization reactor 32 may be operated at a temperature of from 180°C (356°F) to 260°C (500°F). The oligomerization reactor in the second reaction unit 30 may be operated at a pressure of from 2.1 MPa (300 psig) to 8.4 MPaG (1200 psig), more preferably from 4.9 MPa (710 psig) to 7.6 MPa (1100 psig) or from 5.6 MPaG (800 psig) to 6.9 MPa (1000 psig).

[0069] When the oligomerization reaction in second reaction unit 30 is carried out according to the above process conditions, C4 olefin conversions of 95% or greater, or even 97% or greater, are achieved. The resulting third reaction product stream in line 36 comprises olefins, as well as may include multiple olefin products that are distillate range hydrocarbons.

[0070] The oligomerization catalyst can be regenerated upon deactivation. Suitable regeneration conditions include subjecting the oligomerization catalyst, for example, in situ, to hot air at 500°C for three hours. A swing-bed configuration may be used with an alternative oligomerization reactor to facilitate regeneration without downtime. A regeneration gas stream may be introduced into the oligomerization reactor in the second reactor unit 30 requiring regeneration. The regeneration gas may comprise air with an increased or decreased oxygen concentration. The activity and selectivity of the regenerated catalyst are comparable to that of fresh catalyst.

[0071] The third reaction product stream in line 36 may be fractionated in optional fractionation unit 40 to provide specific boiling range products, such as distillate or gasoline or jet fuel, as a second hydrogenation feed stream in line 52 to hydrogenation unit 50. Multiple streams may be produced, some of which may be discharged from the process or recycled within the process. In a preferred embodiment, the second hydrogenation feed stream in line 52 comprises primarily distillate. Alternatively, the third reaction product stream in line 36 may be fed directly to hydrogenation unit 50 as the second hydrogenation feed stream in line 52.

[0072] A first hydrogenation feed stream comprising the first electrolyzer product stream in line 26 is supplied to hydrogenation unit 50. In a preferred embodiment, the first electrolyzer product stream may be supplied to hydrogenation unit 50 without changing the temperature or pressure of the stream. A second hydrogenation feed stream comprising olefins in line 52 is also supplied to hydrogenation unit 50. In one aspect, the second hydrogenation feed stream and the first electrolyzer product stream may be derived from the first feed stream in line 12. Hydrogenation unit 50 may be in downstream communication with first reaction unit 10 and electrolyzer unit 20.

[0073] The hydrogenation unit 50 performs the hydrogenation of olefins to paraffins. The hydrogenation is typically carried out using a conventional hydrogenation or hydrotreating catalyst, which may include, for example, metal catalysts containing palladium, rhodium, nickel, ruthenium, platinum, rhenium, cobalt, molybdenum, or combinations thereof, and supported metal catalysts thereof. The catalyst support may be any solid, inert material, including, but not limited to, oxides such as silica, alumina, titania, calcium carbonate, barium sulfate, and carbon. The catalyst support may be in the form of a powder, granules, pellets, or the like.

[0074] In an exemplary embodiment, hydrogenation is carried out in a hydrogenation reactor 50 containing an alumina-supported platinum catalyst, for example, 0.5 wt. % to 0.9 wt. % alumina-supported platinum catalyst. The hydrogenation reactor converts olefins to paraffin products having the same carbon number distribution as the olefins, thereby forming distillate-range paraffins suitable for use as jet and diesel fuels. An excess of hydrogen, such as 1.5 to 2.5 stoichiometric hydrogen, can be used to ensure complete saturation.

[0075] The hydrogenation reaction conditions may include a temperature of 100°C to 300°C, or 150°C to 250°C, or 165°C to 200°C. The hydrogenation reaction conditions may also include a pressure of 400 psig to 800 psig, or 500 psig to 700 psig, and a weight hourly space velocity (WHSV) of 1 to 5, or 1.8 to 4.2, or 2 to 3. The hydrogenation reaction conditions may further include a hydrogen to olefin molar ratio of 1 to 5, or 1.5 to 4, or 2 to 3.

[0076] Hydrogenation unit 50 produces a hydrogenation product stream comprising paraffins in line 56. A portion of this hydrogenation product stream may be separated and used as a diluent stream in line 58, fed to second reaction unit 30 to help control exotherms, or recycled within hydrogenation unit 50. In one embodiment, the olefin content in the second mixed hydrogenation feed stream in line 55 may comprise, by weight, 5% to 50%, or 6% to 30%, or 7% to 20%.

[0077] The disclosed process can efficiently produce green jet fuel and green diesel fuel that meet applicable fuel requirements, starting from ethanol. Carbon recovery in the process can exceed 95%. The hydrogen used to produce paraffins that meet SPK standards is produced by electrolysis of water produced in the first reaction unit.

[0078] Specific Embodiments While the following will be described in conjunction with specific embodiments, it will be understood that this description is illustrative, but not intended to limit the scope of the preceding description and appended claims.

[0079] A first aspect of the present invention is a method for the hydrogenation of olefins, comprising: providing a first feed stream comprising oxygenated hydrocarbons to a first reaction unit; reacting the first feed stream to produce a first reaction product stream comprising olefins and a second reaction product stream comprising water; electrolyzing the second reaction product stream to produce an electrolyzer product stream comprising hydrogen; providing the first hydrogenation feed stream comprising hydrogen and the second hydrogenation feed stream comprising olefins to a hydrogenation unit; and hydrogenating the second hydrogenation feed stream over a hydrogenation catalyst at hydrogenation reaction conditions in the presence of the first hydrogenation feed stream to form a hydrogenation product stream comprising paraffins, wherein the first hydrogenation feed stream and the second hydrogenation feed stream are obtained from the first feed stream. One embodiment of the present invention is one, any, or all of the previous embodiment to the first embodiment of this paragraph, wherein the first feed stream comprises ethanol. An embodiment of the present invention is any one, any, or all of the preceding embodiments through the first embodiment of this paragraph, wherein the first feedstream comprises triglycerides. An embodiment of the present invention is any one, any, or all of the preceding embodiments through the first embodiment of this paragraph, wherein the first reaction unit comprises dehydration of alcohols to olefins under dehydration reaction conditions. An embodiment of the present invention is any one, any, or all of the preceding embodiments through the first embodiment of this paragraph, wherein the dehydration reaction conditions comprise a temperature of 400°C to 550°C and a pressure of 317 kPa (gauge) (45 psig) to 2068 kPa (300 psig). An embodiment of the present invention is any one, any, or all of the preceding embodiments through the first embodiment of this paragraph, wherein the catalyst comprises gamma alumina. An embodiment of the invention is one, any, or all of the previous to the first embodiment of this paragraph, wherein the electrolyzer product stream comprises greater than 95% hydrogen at a pressure of 35 barg (508 psig) to 70 barg (1015 psig).An embodiment of the invention is one, any, or all of the previous to the first embodiment of this paragraph, further comprising compressing the electrolyzer product stream to hydrogenation reaction conditions.

[0080] A second aspect of the present invention is a method for the hydrogenation of olefins, comprising: providing a first feed stream comprising oxygenated hydrocarbons to a first reaction unit; reacting the first feed stream to produce a first reaction product stream comprising olefins and a second reaction product stream comprising water; electrolyzing the second reaction product stream to produce an electrolyzer product stream comprising hydrogen; providing the first hydrogenation feed stream comprising the electrolyzer product stream and the second hydrogenation feed stream comprising the first reaction product stream to a hydrogenation unit; and hydrogenating the second hydrogenation feed stream over a hydrogenation catalyst at hydrogenation reaction conditions in the presence of the first hydrogenation feed stream to form a hydrogenation product stream comprising paraffins. One embodiment of the present invention is one, any, or all of the previous through second embodiments of this paragraph, wherein the first feed stream comprises ethanol. One embodiment of the present invention is one, any, or all of the previous through second embodiments of this paragraph, wherein the first feed stream comprises triglycerides. An embodiment of the present invention is one, any, or all of the preceding through second embodiments of this paragraph, where the first reaction unit comprises dehydration of alcohols to olefins at dehydration reaction conditions. An embodiment of the present invention is one, any, or all of the preceding through second embodiments of this paragraph, where the dehydration reaction conditions comprise a temperature of 400°C to 550°C and a pressure of 317 kPa (gauge) (45 psig) to 2068 kPa (300 psig). An embodiment of the present invention is one, any, or all of the preceding through second embodiments of this paragraph, where the catalyst comprises gamma alumina. An embodiment of the present invention is one, any, or all of the preceding through second embodiments of this paragraph, where the electrolyzer product stream comprises greater than 95% hydrogen at a temperature of 40°C (104°F) to 120°C (248°F). An embodiment of the present invention is one, any, or all of the previous embodiment of this paragraph through the second embodiment of this paragraph, further comprising compressing the electrolyzer product stream to hydrogenation reaction conditions.

[0081] A third aspect of the present invention is a process for the hydrogenation of olefins, comprising: providing a first feed stream comprising oxygenated hydrocarbons to a first reaction unit; reacting the first feed stream to produce a first reaction product stream comprising olefins and a second reaction product stream comprising water; electrolyzing the second reaction product stream to produce an electrolyzer product stream comprising hydrogen; reacting the first reaction product stream over an oligomerization catalyst in an oligomerization unit at oligomerization conditions to provide a third reaction product stream comprising olefins; providing the first hydrogenation feed stream comprising hydrogen and the second hydrogenation feed stream comprising olefins to a hydrogenation unit; and hydrogenating the second hydrogenation feed stream over a hydrogenation catalyst at hydrogenation reaction conditions to form a hydrogenation product stream comprising paraffins, wherein the first hydrogenation feed stream and the second hydrogenation feed stream are obtained from the first feed stream, and the first hydrogenation feed stream comprises the electrolyzer product stream. An embodiment of the present invention is any one, any, or all of the preceding through third embodiments of this paragraph, wherein the oligomerization reaction conditions comprise a temperature of 100°C to 260°C and a pressure of 2.1 MPa to 8.4 MPa. An embodiment of the present invention is any one, any, or all of the preceding through third embodiments of this paragraph, wherein the oligomerization catalyst comprises a zeolite having a one-dimensional pore structure of 10-membered rings or a metal-supported catalyst. An embodiment of the present invention is any one, any, or all of the preceding through third embodiments of this paragraph, wherein the second hydrogenation feed stream comprises a third reaction product stream.

[0082] Without further elaboration, it is believed that, using the preceding description, one skilled in the art can utilize the present invention to its fullest extent and easily ascertain the essential characteristics of the present invention, and can make various changes and modifications to the present invention to adapt it to various uses and conditions, without departing from the spirit and scope of the present invention. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way, and are intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

[0083] Above, all temperatures are set forth in degrees Celsius and all parts and percentages are by weight unless otherwise indicated.

Claims

1. 1. A process for hydrogenating olefins, comprising: providing a first feed stream comprising oxygenated hydrocarbons to a first reaction unit; reacting the first feed stream to produce a first reaction product stream comprising olefins and a second reaction product stream comprising water; electrolyzing the second reaction product stream to produce an electrolyzer product stream comprising hydrogen; providing a first hydrogenation feed stream comprising hydrogen and a second hydrogenation feed stream comprising olefins to a hydrogenation unit; hydrogenating the second hydrogenation feed stream over a hydrogenation catalyst at hydrogenation reaction conditions in the presence of the first hydrogenation feed stream to form a hydrogenation product stream comprising paraffins; Including, The method wherein said first hydrogenation feed stream and said second hydrogenation feed stream are obtained from said first feed stream.

2. The method of claim 1 , wherein the first feed stream comprises ethanol.

3. 10. The method of claim 1, wherein the first feedstream comprises triglycerides.

4. 10. The method of claim 1, wherein the first reaction unit comprises the dehydration of an alcohol to an olefin under dehydration reaction conditions.

5. 5. The method of claim 4, wherein the dehydration reaction conditions include a temperature of from 400°C to 550°C and a pressure of from 317 kPa (gauge) (45 psig) to 2068 kPa (300 psig).

6. The method of claim 5 wherein the catalyst comprises gamma alumina.

7. 10. The method of claim 1, wherein the electrolyzer product stream comprises greater than 95% hydrogen at a pressure of 35 barg (508 psig) to 70 barg (1015 psig).

8. 10. The method of claim 1, further comprising compressing the electrolyzer product stream to hydrogenation reaction conditions.

9. 10. The method of claim 1, further comprising reacting the first reaction product stream over an oligomerization catalyst in an oligomerization unit at oligomerization conditions to provide a third reaction product stream.

10. 10. The method of claim 1, wherein the first hydrogenation feed stream comprises the electrolyzer product stream.

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