Process for hydrogenation of olefins

Abstract

An integrated process for hydrogenating olefins is described in which a hydrogen stream is generated from electrolysis of water. A water source is from a first reaction step in which a first feed stream comprising oxidized hydrocarbons is reacted to produce a first reaction product stream comprising olefins and a second reaction product stream comprising water. The second reaction product stream is electrolyzed to produce an electrolyzer product stream comprising hydrogen. Hydrogen is used to hydrogenate olefins. A paraffin stream may be obtained from the hydrogenated effluent.

Description

[0001] Priority Claim

[0002] This application claims priority to U.S. Provisional Application No. 63 / 411,693, filed Sep. 30, 2022, which is incorporated herein by reference in its entirety. Technical Field

[0003] This field uses a hydrogen gas stream generated by the electrolysis of water to hydrogenate a stream containing olefins. Background Art

[0004] Jet fuel is one of the few petroleum fuels that cannot be easily replaced by electric motor systems because of the high energy output required to power aircraft. Jet fuel consists of 75% paraffins and 25% aromatics, as described in ASTM D1655. 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 an aromatic content as low as 0.5 wt%. In some regions, there are currently significant incentives for green jet fuel.

[0005] Ethanol is a bio-derived 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 can oligomerize smaller olefins into larger olefins. More specifically, it can convert olefins (including dimerized olefins) into distillates (including jet fuel and diesel-range products). The oligomerized distillates can be saturated to be used as transportation fuels with high stability.

[0006] Methods for chemical conversion using electrochemical cells have also been described. Generally, an electrochemical cell contains an anode, a cathode, and an electrolyte. Catalysts can be placed on the anode, cathode, and / or in the electrolyte to facilitate the desired chemical reaction. During operation, a reactant or a solution containing the reactant is fed into the cell. Then a voltage (potential difference) is applied between the anode and the cathode to facilitate the desired electrochemical reaction. When water is the reactant and the products include oxygen and hydrogen, the reaction is generally referred to as water splitting or electrolysis, and the reactor is an electrolyzer.

[0007] Accordingly, there is a need for methods for the hydrogenation of olefins to allow the use of bio-derived feedstocks such as ethanol as a source of transportation fuel. Summary of the Invention

[0008] We have developed an integrated process for the hydrogenation of olefins, in which the hydrogen stream is generated by the electrolysis of water. The water source is from a first reaction step, in which a first feed stream is reacted to produce a first reaction product stream containing olefins and a second reaction product stream containing water, and the second reaction product stream is electrolyzed to produce an electrolyzer product stream containing hydrogen. The paraffin stream can be obtained from the hydrogenated effluent. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic elevation view of the process of the present disclosure.

[0010] Definition

[0011] The term "in fluid communication" means that fluid flow is operably permitted between the recited components, which may be characterized as "fluidly connected".

[0012] The term "downstream communication" means that at least a portion of the fluid flowing toward the body in the downstream communication can flow operably from an object with which it is in fluid communication.

[0013] The term "upstream communication" means that at least a portion of the fluid flowing out of the body in the upstream communication can flow operably toward an object with which it is in fluid communication.

[0014] The term "direct communication" means that the fluid flow from the upstream component enters the downstream component without passing through any other intermediate container.

[0015] The term "indirect communication" means that the fluid flow from the upstream component enters the downstream component after passing through an intermediate container.

[0016] As used herein, the terms "substantial", "predominant" or "substantially" mean greater than 50%, suitably greater than 75%, and preferably greater than 90%.

[0017] The term "column" means one or more distillation columns for separating one or more components having different volatilities. Unless otherwise specified, each column includes a condenser at the top of the column for condensing a portion of the overhead stream 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 bottoms stream 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 overhead vapor at the vapor outlet of the column. The bottom temperature is the liquid bottoms outlet temperature. The overhead line and the bottoms line refer to the net lines from any reflux or reboiling downstream of the column to the column. A stripping column can omit the reboiler at the bottom of the column and instead provide the heating requirement and separation driving force for a liquefied inert medium (such as steam). A stripping column typically feeds from the top tray and withdraws the main product from the bottom.

[0018] As used herein, the term "separator" means a vessel having an inlet and at least one overhead vapor outlet and one bottoms liquid outlet, and may also have an aqueous stream outlet from a boot. A flash drum is a type of separator that can be in communication downstream of a separator that can operate at a higher pressure. As used herein, the term "boiling point temperature" means the atmospheric equivalent boiling point (AEBP) calculated from the observed boiling temperature and the distillation pressure, as calculated using the formula provided in ASTM D1160, Appendix A7, entitled "Practice for Converting Observed Vapor Temperatures to Atmospheric Equivalent Temperatures".

[0019] The term "unit" shall be understood to mean one or more process steps including chemical conversion. At the center of the unit is one or more catalytic reactors or separation vessels necessary to effect the conversion. The unit may also include additional separation vessels, which include fractionation towers to separate product streams. The unit may also include a pretreatment step for chemical conversion. In general, a "unit" includes one or more reactors or separation vessels and separation steps and pretreatment steps, whether or not shown in the figures or explicitly discussed in the specification.

[0020] As used herein, the terms "T5", "T90", or "T95" mean the temperature at which 5 mass percent, 90 mass percent, or 95 mass percent, as appropriate, of a sample boils using ASTM D-86 or TBP.

[0021] 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 appropriate.

[0022] As used herein, the term "end point" (EP) means the temperature at which a sample has completely boiled using ASTM D-7169, ASTM D-86, or TBP, as appropriate.

[0023] As used herein, the terms "diesel" and / or "distillate" mean hydrocarbons that boil within the following ranges: an IBP between 125°C (257°F) and 175°C (347°F), or a T5 between 150°C (302°F) and 200°C (392°F), and a "diesel cut point", including a T95 between 343°C (650°F) and 399°C (750°F) using the TBP distillation method, or a T90 between 280°C (536°F) and 340°C (644°F) using ASTM D - 86. The term "green diesel" or "green distillate" means a diesel containing hydrocarbons not derived from fossil fuels.

[0024] As used herein, the term "jet fuel" refers to hydrocarbons that boil within the T10 range between 190°C (374°F) and 215°C (419°F) and have an end point between 290°C (554°F) and 310°C (590°F). The term "green jet fuel" means a jet fuel containing hydrocarbons not derived from fossil fuels.

[0025] As used herein, "electrolyzer" is intended to denote a device containing a cathode (negative charge), an anode (positive charge), and a membrane. The entire system may also contain pumps, vents, storage tanks, power supplies, separators, and / or other components. Typically, these devices are used to cause an electrochemical reaction, such as water electrolysis, within a stack of electrolyzer cells. An electric current is applied across the membrane to the anode and cathode, which, in the case of water electrolysis, causes water to decompose into its component molecules hydrogen (H2) and oxygen (O2).

[0026] The term "cathode" refers to an electrode through which conventional current exits a polarized electrical device and electrons flow into the electrode from the outer or external circuit connected to the cell. A reduction reaction occurs at the cathode. [[ID=!]]

[0027] The term "anode" refers to an electrode through which conventional current enters a polarized electrical device and electrons flow out to the outer or external circuit connected to the cell. An oxidation reaction occurs at the anode. Detailed Description

[0028] The disclosed method includes providing a first feed stream containing oxidized hydrocarbons to a first reaction unit, reacting the first feed stream to produce a first reaction product stream containing olefins and a second reaction product stream containing water, electrolyzing the second reaction product stream to produce an electrolyzer product stream containing hydrogen, providing a first hydrogenation feed stream containing hydrogen and a second hydrogenation feed stream containing olefins to a hydrogenation unit, and hydrogenating the second hydrogenation feed stream over a hydrogenation catalyst under hydrogenation reaction conditions to form a hydrogenation product stream containing paraffins.

[0029] Turning Figure 1In the accompanying drawings, the first feed stream flowing in pipeline 12 to the first reaction unit 10 may contain oxidized hydrocarbons. The oxidized hydrocarbons include ethanol, propanol, other alcohols, and / or triglycerides. Preferably, the oxidized hydrocarbons have a biological origin such as fermentation or are derived from vegetable oils. In an exemplary embodiment, the first feed stream in pipeline 12 may contain ethanol. The first feed stream in pipeline 12 may predominantly contain ethanol. The first reaction unit 10 may include ethanol dehydration.

[0030] The dehydration converts ethanol into ethylene and water. Ethanol dehydration is a highly endothermic reaction. Steam may be added to the reactor to help control the endothermicity and reduce coke deposition to improve the stability of the catalyst. The water recycle stream in pipeline 17 may additionally contain a portion of the combined first feed stream in pipeline 14. Unconverted ethanol may also be recycled in the recycle feed stream in pipeline 15 to contain a portion of the combined first feed stream in pipeline 14.

[0031] The combined first feed stream may be heated in one or more stages by a heat exchanger, a fired heater, or a combination thereof. In an exemplary embodiment, a portion of the heat generated in the hydrogenation unit 50 is captured as hot steam and used to help heat the first combined feed stream in pipeline 14 to a temperature of up to about 400 °C. Thus, the hydrogenation unit 50 and the first reaction unit 10 may be heat integrated. Greater than 10% or greater than 25% or greater than 50% of the heat required for the reaction in the first reaction unit 10 may be supplied from the hydrogenation unit 50 by heat integration. The fired heater may also help provide sufficient heat. Before passing through a dehydration catalyst at a pressure of 317 kPa (gage) (45 psig) to 2068 kPa (300 psig) or 345 kPa (50 psig) to 630 kPa (gage) (90 psig), the first combined feed stream may be further heated to a dehydration reaction temperature of 400 °C to 550 °C. An acceptable pressure may also be 1379 kPa (200 psig) to 1724 kPa (250 psig).

[0032] In one aspect, the ethanol dehydration catalyst may be an alumina-based catalyst. The dehydration catalyst may substantially comprise γ-alumina.

[0033] In an alternative embodiment, the first reaction unit 10 may include hydrotreating. A suitable feed stream flowing in line 12 to the hydrotreating unit may contain triglycerides derived from vegetable oils. Renewable feedstocks useful in the present invention include any of those containing glycerides and free fatty acids (FFAs). Examples of such feedstocks include, but are not limited to, canola oil, corn oil, soybean oil, rapeseed oil, soybean oil, high erucic acid rapeseed oil, tall oil, sunflower 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, fat in milk, fish oil, algal oil, sewage sludge, cuphea oil, camelina oil, jatropha oil, jatropha curcas oil, babassu oil, palm kernel oil, sea kale oil, etc. Bio-renewable is another term used to describe these feedstocks. The glycerides, FFAs, and fatty acid alkyl esters of typical vegetable oils or animal fats contain aliphatic hydrocarbon chains having 8 to 24 carbon atoms in their structures, with most oils containing a high concentration of fatty acids having 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, particularly in combination with the feedstocks listed above as co-feed components, include waste motor oil and industrial lubricants, used paraffin wax, liquids derived from the gasification of coal, biomass, or natural gas and subsequent downstream liquefaction steps such as Fischer-Tropsch technology; liquids derived from the pyrolytic or chemical depolymerization of waste plastics such as polypropylene, high-density polyethylene, and low-density polyethylene; and other synthetic oils produced as by-products of 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 the conversion of materials that have been considered waste products from fossil fuel-based processes or other processes into co-feed components that are valuable to the current process. In this alternative embodiment, the first feed stream in line 12 may be contacted with a multifunctional catalyst or a catalyst set having hydrogenation, deoxygenation, isomerization, and selective hydrocracking functions to produce a reaction effluent containing water, carbon oxides, light hydrocarbon gases, hydrogen, and alkanes. The water, carbon oxides, light hydrocarbon gases, and hydrogen are separated from the reaction effluent to produce a liquid stream containing alkanes.

[0034] As mentioned above, the multifunctional catalyst or catalyst set includes deoxygenation, hydrogenation, isomerization, and selective hydrocracking functions. The deoxygenation and hydrogenation functions, which can be the same or separate active sites, can be noble metals, such as platinum group metals, including but not limited to ruthenium, rhodium, palladium, platinum, and mixtures thereof, at levels in the range of 0.05 wt% to 2.0 wt% of the catalytic composite. Some catalysts can contain up to 10 wt% of platinum on carbon or palladium on carbon. Examples of other active sites that can be used to provide the deoxygenation and hydrogenation functions are sulfided base metals, such as sulfided NiMo or sulfided NiW. Base metals are metals that oxidize when heated in air, and other base metals that can be catalyst components in the present context, in addition to nickel, molybdenum, and tungsten, include iron, lead, zinc, copper, tin, germanium, chromium, titanium, cobalt, rhenium, indium, gallium, uranium, dysprosium, thallium, and mixtures and compounds thereof. Regarding the isomerization and selective hydrocracking functions, the second part of the catalyst composite can contain a zeolite having an acidic function capable of catalyzing isomerization and selective hydrocracking reactions. The zeolite concentration can be in the range of 1 wt% to 99 wt% of the catalyst composite, depending on the type of zeolite used and the operating conditions. In one embodiment, the zeolite contains medium to large-sized pores having 10 - 12 membered rings, such as BEA, MOR, MFI, or FAU. In other embodiments, the cracking function is an amorphous acid site found in a material such as amorphous silica-alumina. In another embodiment, a portion of the support has a high external surface area greater than 150 m2 / g or large mesopores with an average pore diameter greater than 45 Å to bring large triglyceride molecules in close proximity to the catalytically active sites to the greatest extent. This is beneficial because a highly porous structure with large openings will reduce diffusion problems that could otherwise impede the contact of large glyceride molecules with the active sites of the catalyst. Additionally, the large pores will impede the diffusion resistance of the jet-range paraffins produced during this catalytic process and prevent further cracking into lower-value light products. Examples of catalysts or catalyst sets that can successfully catalyze deoxygenation, hydrogenation, isomerization, and selective hydrocracking reactions in the same reaction zone include platinum dispersed on a support containing Y-zeolite. Another example is platinum and palladium on a support containing Y-zeolite combined with amorphous silica alumina. Examples of catalyst sets include sulfided NiMo supported on amorphous silica alumina and platinum supported on amorphous silica alumina.

[0035] In this embodiment, the inlet temperature of the catalyst bed within the first reaction unit 10 can be in the range of 150 °C to 454 °C (300 °F to 850 °F), and the inlet pressure should be higher than 1379 kPa gauge to 13,790 kPa gauge (200 psig to 2,000 psig). The feed stream is admixed with sufficient hydrogen to provide a hydrogen recycle rate of 168 nl / l to 1684 nl / l (1000 standard cubic feet per barrel to 10,000 standard cubic feet per barrel, hereinafter referred to as SCFB), and is passed into a reactor containing a catalyst or catalyst pack. The hydrogen can be mainly sourced from the recycle gas stream, and the recycle gas stream can be 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 admixed with the feed and any hydrocarbon-containing recycle stream in one embodiment will contain at least 90 mole percent hydrogen. The feed rate in terms of liquid hourly space velocity (L.H.S.V.) will generally be in the broad range of 0.3 hr -1 to 5 hr -1 wherein an L.H.S.V. of less than 1.2 is used in one embodiment.

[0036] The first reaction unit 10 can produce a plurality of product streams after the reaction of the first feed stream. These can include the recycle feed vapor in line 15, the first reaction product stream in line 16, and the second reaction product stream in line 18. Additional streams can be produced. A light gas stream and / or a heavy olefin stream can be produced. The first reaction product stream in line 16 can contain olefins. The second reaction product stream in line 18 can contain water and preferably mainly contains water. The second reaction product stream in line 18 can be passed into a buffer tank 19 to accumulate sufficient product or to be treated and / or purified prior to further processing.

[0037] If the first reaction unit includes ethanol dehydration, the first reaction product stream in line 16 may contain ethylene or may predominantly contain ethylene. The first reaction product stream in line 16 may leave the first reaction unit 10 at a pressure of from 317 kPa (gage) (45 psig) to 630 kPa (gage) (90 psig) or from 345 kPa (gage) (50 psig) to 414 kPa (gage) (60 psig). The first reaction product stream may be compressed using one or more compression stages before further reaction in the second reaction unit 30. The first stage compressor may compress the first reaction product stream to a first pressure of from 350 kPa (gage) (50 psig) to 1225 kPa (gage) (175 psig). The second stage compressor may compress the first reaction product stream to a second pressure of from 455 kPa (gage) (165 psig) to 3220 kPa (gage) (460 psig). The third stage of compression may compress the first reaction product stream to a third pressure of from 5.6 MPag (800 psig) to 8.4 MPag (1200 psig).

[0038] In one aspect, a second reaction product stream containing water may be produced after one or more compression stages. Preferably, the second reaction product stream is in the liquid phase. The second reaction product stream in line 18 may be fed directly or after passing through buffer tank 19 via electrolyzer feed line 22 to electrolyzer unit 20. The electrolyzer unit includes an electrolyzer.

[0039] The electrolyzer unit 20 may include an electrolyzer catalyst. The electrolyzer catalyst may comprise platinum (Pt). The electrolyzer catalyst may comprise platinum supported on carbon. The loading of platinum on carbon may be in the range of from 0.1 mg / cm 2 to 1 mg / cm 2 The electrolyzer feed stream containing water from the second reaction product stream may be further increased to include an alkaline aqueous solution. Due to its high conductivity, potassium hydroxide (KOH) may be a preferred component of the electrolyzer feed stream. Other electrolytes such as bicarbonates, sulfates or chlorides (KHCO3, K2SO4 and KCl) may also be used. No electrolyte may be used. The concentration of KOH in the electrolyzer feed stream may be in the range of from 0.1 M to 1.5 M. The current density in the electrolyzer unit 20 may be related to the KOH concentration in the electrolyzer anode reactant, where higher current densities are achieved at higher KOH concentrations. The concentration of KOH in the electrolyzer feed stream may be in the range of from 0.1 M to 1.5 M. A voltage of from 1.5 V to 5 V may be applied between the anode and the cathode within the electrolyzer unit 20. A lower applied voltage is preferred. A voltage of less than 2 V may be applied between the electrolyzer anode and the electrolyzer cathode.

[0040] Electrolyzer 20 converts water into hydrogen and oxygen. The first electrolysis product stream in line 26 may contain hydrogen and preferably consists mainly of hydrogen. The first electrolysis product stream may contain more than 95% hydrogen, or more than 98% hydrogen, or more than 99% hydrogen. The first electrolysis product stream may contain nearly 100% hydrogen, such as 99.9% hydrogen. In one aspect, the temperature of the first electrolysis product stream in line 26 is from 40 °C (104 °F) to 120 °C (248 °F) and the pressure is from 35 barg (508 psig) to 70 barg (1015 psig). The second electrolysis product stream in line 28 may contain oxygen. The second electrolysis product stream may consist mainly of oxygen. Oxygen can be a valuable product and is recovered for use as a feed to a fuel cell for power generation or medical purposes or other industrial applications.

[0041] The method 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, the third reaction product stream containing olefins having an average molecular weight higher than that of the first reaction product stream in line 16. Exemplary processes in the second reaction unit 30 include one or more oligomerization steps on one or more oligomerization catalysts under oligomerization conditions in an oligomerization unit to provide the third reaction product stream in line 36 containing olefins.

[0042] Oligomerization may include dimerizing an olefin stream containing ethylene, followed by further oligomerization of the ethylene dimer and ethylene oligomers. The resulting oligomers can be separated to provide a distillate stream, which can be saturated to provide a distillate fuel. The saturated stream can be recycled as a diluent to ethylene dimerization to absorb the heat of dimerization and / or oligomerization. Additionally, the olefin stream in line 16 can be separated and charged to more than one catalyst bed, also to manage the exotherm. The dimerization products of the catalyst bed that may contain unreacted olefins are also passed to the downstream bed, thus increasing the overall single-pass conversion. Additionally, the dimerization products of the upstream catalyst bed are used as additional diluents to absorb the exotherm in the downstream catalyst bed.

[0043] The second reaction unit feed stream in line 16 may contain a large amount of ethylene. The feed stream may consist mainly of ethylene. In one aspect, the feed stream may contain at least 95 mol% ethylene.

[0044] The temperature of the second reaction unit feed stream in line 16 may be from 60 °C (140 °F) to 190 °C (374 °F), preferably from 100 °C (212 °F) to 170 °C (338 °F), and the pressure is from 5.6 MPag (800 psig) to 8.4 MPag (1200 psig).

[0045] The second reaction unit 30 may include a dimerization reactor 32 and an oligomerization reactor 34. The dimerization and oligomerization reactors may be one reactor or may be multiple reactors. The second reaction unit feed stream may initially contact a dimerization catalyst to dimerize ethylene into dimers and then contact an oligomerization catalyst to oligomerize the dimers of ethylene. The oligomerization catalyst may be placed upstream of the dimerization catalyst.

[0046] The dimerization reaction may occur primarily in the liquid phase or in a mixed liquid and gas phase based on the olefin at a LHSV of 0.5 hr -1 to 10 hr -1 . We have found that the major fraction of ethylene in the olefin stream is converted to higher olefins. Typically, at least 90 mole % to 95 mole % of the ethylene will dimerize passing through the dimerization catalyst bed. The ethylene will initially dimerize above the catalyst to butene.

[0047] The dimerization catalyst may comprise a metal supported catalyst. The dimerization catalyst is preferably an amorphous silica-alumina based material having a metal from Group VIII and / or Group VIB of the Periodic Table using Chemical Abstracts Service designations. In one aspect, the catalyst has a Group VIII metal promoted with a Group VIB metal. Typically, the silica and alumina are only in the base material, so the silica / alumina ratio of the catalyst is the same as the base material. The metal may be impregnated onto the silica-alumina base material or ion exchanged with the silica-alumina base material. Co-grinding is also contemplated. The catalyst for use in 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 determined by the ammonia temperature programmed desorption method (ammonia TPD) described below. Additionally, a suitable catalyst will have a surface area between 50 and 400 m 2 / g as determined by nitrogen BET.

[0048] Preferred dimerization catalysts are described below. The preferred dimerization catalysts comprise an amorphous silica-alumina support. One of the components of the catalyst support for use in the present invention is alumina. The alumina can be any of various hydrated aluminum oxides or alumina gels such as α-aluminum oxide monohydrate of the boehmite or pseudoboehmite structure, α-aluminum oxide trihydrate of the gibbsite structure, β-aluminum oxide trihydrate of the bayerite structure, etc. Particularly preferred alumina can be purchased from Sasol North America Alumina Product Group under the trade name Catapal. The material is a very high purity α-aluminum oxide monohydrate (pseudoboehmite) which has been shown to produce high purity γ-aluminum oxide after calcination at high temperature. Another component of the catalyst support is amorphous silica-alumina. A suitable silica-alumina with a silica to alumina ratio of 2.6 is purchased from Japan CCIC (a subsidiary of JGC).

[0049] Another component used to prepare the catalyst for use in the present invention is a surfactant. Preferably the surfactant is mixed with the above-described alumina and silica-alumina powders. The resulting mixture of surfactant, alumina, and silica-alumina 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 according to the present invention. Any suitable surfactant can be used according to the present invention. Preferred surfactants are surfactants selected from a series of commercial surfactants sold by Solvay S.A. under the trade name "Antarox". "Antarox" surfactants are generally characterized as modified linear aliphatic polyethers and are low-foaming biodegradable detergents and wetting agents.

[0050] A suitable silica-alumina mixture is prepared by mixing volumes of silica-alumina and alumina in a ratio to achieve the desired silica to alumina ratio. In one embodiment, 75 wt% to 95 wt% amorphous silica-alumina and 10 wt% to 20 wt% alumina powder will provide a suitable support with a silica to alumina ratio of 2.6. In one embodiment, other ratios of amorphous silica-alumina to alumina may be suitable.

[0051] Any convenient method can be used to combine the surfactant with the silica-alumina and alumina mixture. Preferably, the surfactant is mixed during the mixing and formation of alumina and silica-alumina. A preferred method is to mix an aqueous solution of the surfactant with the blend of alumina and silica-alumina before the final formation of the support. Preferably, based on the weight of alumina and silica-alumina, the surfactant is present in the paste or dough in an amount of 0.01 wt% to 10 wt%.

[0052] A monobasic acid such as nitric acid or formic acid can be added to the mixture in the aqueous solution to peptize the alumina in the binder. Additional water can be added to the mixture to provide sufficient humidity so as to constitute a dough with sufficient consistency to be extruded or spray dried.

[0053] The paste or dough can be prepared in the form of shaped granules. A preferred method is to extrude the dough mixture of alumina, silica-alumina, surfactant and water through a die having openings of the desired size and shape therein, and then break the extruded material into extrudates of the desired length and dry. A further calcination step can be employed to impart increased strength to the extrudates. Generally, the calcination is carried out in a dry air stream at a temperature of 260 °C (500 °F) to 815 °C (1500 °F).

[0054] The extruded granules can have any suitable cross-sectional shape, i.e., symmetric or asymmetric, but most commonly have a symmetric cross-sectional shape, preferably spherical, cylindrical or multi-lobed. The cross-sectional diameter of the granules can be as small as 40 μm; however, it is generally 0.635 mm (0.25 inches) to 12.7 mm (0.5 inches), preferably 0.79 mm (1 / 32 inches) to 6.35 mm (0.25 inches), and most preferably 0.06 mm (1 / 24 inches) to 4.23 mm (1 / 6 inches).

[0055] Typical characteristics of the amorphous silica-alumina support used herein are that the total pore volume, average pore diameter and surface area are large enough to provide a large amount of space and area for depositing the active metal component. As measured by the conventional mercury porosimetry method, the total pore volume of the support is generally 0.2 cc / g to 2.0 cc / g, preferably 0.25 cc / g to 1.0 cc / g, and most preferably 0.3 cc / g to 0.9 cc / g. Generally, the pore volume amount of the support in pores with a diameter greater than 100 Å is less than 0.1 cc / g, preferably less than 0.08 cc / g, and most preferably less than 0.05 cc / g. As measured by the B.E.T. method, the surface area is generally higher than 50 m 2 / g, e.g., higher than 200 m 2 / g, preferably at least 250 m 2 / g, and most preferably 300 m 2from 0 g to 400 m 2 / g.

[0056] To prepare the catalyst, a support material is admixed with one or more precursors of at least one metal component from Group VIII or VIB of the Periodic Table (such as by single or multiple impregnation of amorphous refractory oxide support particles by calcination). The Group VIII metal (preferably nickel) should be present at a concentration of 0.5 wt% to 15 wt%, and the Group VIB metal (preferably tungsten) should be present at a concentration of 0 to 12 wt%. Impregnation can be achieved by any method known in the art (such as, for example, by spray impregnation), where a solution containing the metal precursor in dissolved form is sprayed onto the support particles. Another method is the multi-dip protocol, where the support material is repeatedly contacted with the impregnation solution, with or without intermittent drying. Other methods involve soaking the support in a large volume of the impregnation solution or circulating the support therein, and still another method is the pore volume or pore saturation technique, where the support particles are introduced into an impregnation solution having a volume just sufficient to fill the pores of the support. Sometimes, the pore saturation technique can be modified to utilize an impregnation solution having a volume 10% less to 10% greater than the volume just sufficient to fill the pores.

[0057] If the active metal precursors are incorporated by impregnation, a subsequent or second calcination at an elevated temperature (such as, for example, between 399 °C (750 °F) and 760 °C (1400 °F)) converts the metals to their corresponding oxide forms. In some cases, the calcination can be carried out after each impregnation of the individual active metals. The subsequent calcination produces a catalyst that contains the active metals in their corresponding oxide forms.

[0058] A preferred dimerization catalyst of the present invention has an amorphous silica-alumina base impregnated with 0.5 wt% to 15 wt% nickel, in the form of 3.175 mm (0.125 inch) extrudates and having a density of 0.45 g / ml 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-grinding.

[0059] The dimerization catalyst can be regenerated when passivated. Suitable regeneration conditions include subjecting the catalyst, for example, in situ to hot air at 500 °C for 3 hours. To facilitate regeneration without shutting down, a swing bed arrangement can be employed with an alternative dimerization reactor. The regeneration gas can include air with an increased or decreased oxygen concentration. The activity and selectivity of the regenerated catalyst are comparable to those of a fresh catalyst.

[0060] To manage the exotherm, the feed stream in line 16 may be diluted with a diluent stream to provide a diluted olefin stream to help absorb the exotherm. The diluent stream may comprise an alkane stream in diluent line 58. The first diluted olefin stream may comprise no more than 25 wt% olefins, suitably no more than 10 wt% olefins and preferably no more than 6 wt% olefins. The first diluted olefin stream may comprise no more than 25 wt% ethylene, suitably no more than 10 wt% ethylene and preferably no more than 6 wt% ethylene. A dimerization stream may be produced in line 33.

[0061] The second reaction unit 30 may further include an oligomerization reactor 34.

[0062] 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 is preferably operated in a downward flow operation. However, an upward flow operation may be suitable. The feed oligomerization stream contacts an oligomerization catalyst, resulting in dimerization and trimerization of C2-C8 olefins to provide a distillate range olefin. Most of the butenes in the feed oligomerization stream are oligomerized. In one embodiment, at least 99 mole% of the butenes in the feed oligomerization stream are oligomerized. A third reaction product stream in line 36 having an increased average carbon number greater than the second reaction unit feed stream in line 16 exits the oligomerization reactor 34 and the second reaction unit 30 in line 36.

[0063] The oligomerization catalyst may comprise a zeolite catalyst. The zeolite may be present in the catalyst between 5 wt% and 95 wt%, such as between 5 wt% and 85 wt%. Suitable zeolites include zeolites having a structure in 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. The three-letter codes indicating zeolite classes are as defined by the Structure Commission of the International Zeolite Association and are maintained at http: / / www.iza-structure.org / databases. UZM-8 is as described in U.S. Patent No. 6,756,030. In a preferred aspect, the oligomerization catalyst may comprise a zeolite with a framework having a ten-ring pore structure. Examples of suitable zeolites with a ten-ring pore structure include TON, MTT, MFI, MEL, AFO, AEL, EUO, and FER. In a further preferred aspect, the oligomerization catalyst comprising a zeolite with a ten-ring pore structure may comprise a one-dimensional pore structure. A one-dimensional pore structure indicates a zeolite containing non-crossing pores that are substantially parallel to one of the crystal axes. The pores preferably extend through the zeolite crystal. Suitable examples of zeolites with a ten-ring one-dimensional pore structure may include MTT. In an additional aspect, the oligomerization catalyst comprises MTT zeolite.

[0064] The oligomerization catalyst can be formed by combining the zeolite with a binder and then forming the catalyst into pellets. The pellets may optionally be treated with a phosphorus reagent to yield a zeolite in which the phosphorus component is between 0.5 wt% and 15 wt% 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, chlorite, and sepiolite. Preferred binders are aluminum-based binders such as alumina, aluminum phosphate, silica-alumina, and clays.

[0065] One of the components of the catalyst binder for the present invention is alumina. The alumina source can be any of various hydrated aluminum oxides or alumina gels such as boehmite or pseudo-boehmite structured α-aluminum monohydrate, α-aluminum trihydrate of the gibbsite structure, β-aluminum trihydrate of the bayerite structure, etc. Suitable alumina can be purchased from UOP LLC under the trade name VERSAL. Preferred alumina can be purchased from Sasol North American Alumina Products Group under the trade name Catapal. This material is extremely high purity α-aluminum monohydrate (pseudo-boehmite) which has been shown to produce high purity γ-alumina after calcination at high temperature.

[0066] Suitable oligomerization catalysts are prepared by mixing a proportional volume of zeolite and alumina to achieve the desired zeolite to alumina ratio. In one embodiment, the MTT content can be 5 wt% to 85 wt%, such as 20 wt% to 82 wt% of MTT zeolite, and the balance of alumina powder will provide a suitably supported catalyst. Silica supports are also contemplated.

[0067] A monobasic acid such as nitric acid or formic acid can be added to the mixture in the aqueous solution to peptize the alumina in the binder. Additional water can be added to the mixture to provide sufficient humidity to form a dough of sufficient consistency to be extruded or spray dried. An extrusion aid such as cellulose ether powder can also be added. Preferred extrusion aids can be purchased from Dow Chemical Company under the trade name Methocel.

[0068] The paste or dough can be prepared in the form of shaped granules. The preferred method is to extrude the dough through a die having openings of the desired size and shape, after which the extruded material is broken into extrudates of the desired length and dried. A further calcination step can be employed to impart increased strength to the extrudates. Generally, the calcination is carried out in an air stream at a temperature of 260 °C (500 °F) to 815 °C (1500 °F). The MTT catalyst is not selectively neutralized of acid sites, such as with an amine.

[0069] The extruded granules can have any suitable cross-sectional shape, i.e., symmetric or asymmetric, but most commonly have a symmetric cross-sectional shape, preferably spherical, cylindrical or multi-lobed. The cross-sectional diameter of the granules can be as small as 40 μm; however, it is typically 0.635 mm (0.25 inches) to 12.7 mm (0.5 inches), preferably 0.79 mm (1 / 32 inches) to 6.35 mm (0.25 inches), and most preferably 0.06 mm (1 / 24 inches) to 4.23 mm (1 / 6 inches).

[0070] The oligomerization reactor 32 can be operated at a temperature of 180 °C (356 °F) to 260 °C (500 °F). The oligomerization reactor in the second reaction unit 30 can be operated at a pressure of 2.1 MPa (300 psig) to 8.4 MPag (1200 psig), more preferably 4.9 MPa (710 psig) to 7.6 MPa (1100 psig) or 5.6 MPag (800 psig) to 6.9 MPa (1000 psig).

[0071] When the oligomerization reaction in the second reaction unit 30 is carried out according to the above process conditions, a C4 olefin conversion rate of greater than or equal to 95%, or greater than or equal to 97% is achieved. The resulting third reaction product stream in line 36 contains olefins and can contain a variety of olefin products, which are hydrocarbon in the distillate range.

[0072] The oligomerization catalyst can be regenerated when passivated. Suitable regeneration conditions include subjecting the oligomerization catalyst, for example, in situ, to hot air at 500 °C for 3 hours. To facilitate regeneration without shutting down, a swing bed arrangement can be employed with an alternative oligomerization reactor. A regeneration gas stream can be introduced into the oligomerization reactor within the second reaction unit 30 that needs to be regenerated. The regeneration gas can include air with an increased or decreased oxygen concentration. The activity and selectivity of the regenerated catalyst are comparable to those of the fresh catalyst.

[0073] The third reaction product stream in line 36 can be fractionated in an optional fractionation unit 40 to provide products within a specific boiling range such as distillate or gasoline or jet fuel, as the second hydrogenation feed stream flowing in line 52 to the hydrogenation unit 50. Multiple streams can be produced, some of which can be discharged from the process or recycled within the process. In a preferred embodiment, the second hydrogenation feed stream in line 52 mainly contains distillate. Alternatively, the third reaction product stream in line 36 can be directly fed into the hydrogenation unit 50 as the second hydrogenation feed stream in line 52.

[0074] The first hydrogenation feed stream containing the first electrolysis cell product stream in line 26 is fed into the hydrogenation unit 50. In a preferred embodiment, the first electrolysis cell product stream can be fed into the hydrogenation unit 50 without changing the temperature or pressure of the stream. The second hydrogenation feed stream containing olefins in line 52 is also fed into the hydrogenation unit 50. In one aspect, the second hydrogenation feed stream and the first electrolysis cell product stream can be derived from the first feed stream in line 12. The hydrogenation unit 50 can be in downstream communication with the first reaction unit 10 and the electrolysis cell unit 20.

[0075] The hydrogenation unit 50 performs the hydrogenation of olefins to paraffins. The hydrogenation is typically carried out using conventional hydrogenation or hydrotreating catalysts and may include metal catalysts containing, for example, palladium, rhodium, nickel, ruthenium, platinum, rhenium, cobalt, molybdenum, or combinations thereof, as well as their supported forms. The catalyst support can be any solid, inert material, including but not limited to oxides such as silica, alumina, titanium dioxide, calcium carbonate, barium sulfate, and carbon. The catalyst support can be in the form of powder, granules, pellets, etc.

[0076] In an exemplary embodiment, the hydrogenation is carried out in a hydrogenation reactor within the hydrogenation unit 50, which includes a platinum-on-alumina catalyst, such as a 0.5 wt% to 0.9 wt% platinum-on-alumina catalyst. The hydrogenation reactor converts the olefins into a paraffin product having the same carbon number distribution as the olefins, thereby forming distillate-range paraffins suitable for use as jet fuel and diesel fuel. An excess of hydrogen can be employed to ensure complete saturation, such as 1.5 to 2.5 stoichiometric hydrogen.

[0077] The hydrogenation reaction conditions can 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 can also include a pressure of 400 psig to 800 psig or 500 psig to 700 psig, a weight hourly space velocity (WHSV) of 1 to 5 or 1.8 to 4.2 or 2 to 3. The hydrogenation reaction conditions can also include a hydrogen-to-olefin molar ratio of 1 to 5 or 1.5 to 4 or 2 to 3.

[0078] The hydrogenation unit 50 produces a hydrogenated product stream containing paraffins in line 56. A portion of the hydrogenated product stream can be separated and used as a diluent stream in line 58 and fed to the second reaction unit 30 or recycled within the hydrogenation unit 50 to help control the exotherm. In one aspect, the olefin content in the second combined hydrogenated feed stream in line 55 can be 5 wt% to 50 wt%, or 6 wt% to 30 wt%, or 7 wt% to 20 wt%.

[0079] Starting from ethanol, the disclosed method can effectively produce green jet fuel and green diesel fuel that meet applicable fuel requirements. The carbon recovery in the method can exceed 95%. The hydrogen used to produce paraffins meeting the SPK standard is generated by the electrolysis of water produced in the first reaction unit.

[0080] Specific implementation

[0081] Although the following is described in connection with specific embodiments, it should be understood that the description is intended to illustrate and not limit the scope of the foregoing description and the appended claims.

[0082] A first embodiment of the present invention is a method for the hydrogenation of olefins, the method comprising providing a first feed stream comprising an oxygenated hydrocarbon 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 electrolytic cell product stream comprising hydrogen, providing a first hydrogenation feed stream comprising hydrogen and a second hydrogenation feed stream comprising olefins to a hydrogenation unit, and hydrogenating the second hydrogenation feed stream over a hydrogenation catalyst under 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 derived from the first feed stream. One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph to the first embodiment of this paragraph, wherein the first feed stream comprises ethanol. One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph to the first embodiment of this paragraph, wherein the first feed stream comprises triglycerides. One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph to the first embodiment of this paragraph, wherein the first reaction unit comprises dehydrating an alcohol to an olefin under dehydration reaction conditions. One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph to the first embodiment of this paragraph, wherein the dehydration reaction conditions include a temperature of 400 °C to 550 °C and a pressure of 317 kPa (gauge) (45 psig) to 2068 kPa (300 psig). One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph to the first embodiment of this paragraph, wherein the catalyst comprises gamma alumina. One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph to the first embodiment of this paragraph, wherein the electrolytic cell product stream comprises greater than 95% hydrogen at a pressure of 35 barg (508 psig) to 70 barg (1015 psig). One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph to the first embodiment of this paragraph, further comprising compressing the electrolytic cell product stream to hydrogenation reaction conditions.

[0083] A second embodiment of the present invention is a method for the hydrogenation of olefins, the method comprising providing a first feed stream comprising an oxidized hydrocarbon 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 the electrolyzer product stream and a 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 under hydrogenation reaction conditions in the presence of the first hydrogenation feed stream to form a hydrogenated product stream comprising paraffins. One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph to the second embodiment of this paragraph, wherein the first feed stream comprises ethanol. One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph to the second embodiment of this paragraph, wherein the first feed stream comprises triglycerides. One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph to the second embodiment of this paragraph, wherein the first reaction unit comprises dehydrating an alcohol to an olefin under dehydration reaction conditions. One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph to the second embodiment of this paragraph, wherein the dehydration reaction conditions include a temperature of 400 °C to 550 °C and a pressure of 317 kPa (gage) (45 psig) to 2068 kPa (300 psig). One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph to the second embodiment of this paragraph, wherein the catalyst comprises γ-alumina. One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph to the second embodiment of this paragraph, wherein the electrolyzer product stream comprises greater than 95% hydrogen at a temperature of 40 °C (104 °F) to 120 °C (248 °F). One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph to the second embodiment of this paragraph, further comprising compressing the electrolyzer product stream to hydrogenation reaction conditions.

[0084] A third embodiment of the present invention is a method for the hydrogenation of olefins, the method comprising providing a first feed stream comprising an oxidized hydrocarbon 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 electrolytic cell product stream comprising hydrogen, reacting the first reaction product stream in an oligomerization unit under oligomerization conditions over an oligomerization catalyst to provide a third reaction product stream comprising olefins, providing a first hydrogenation feed stream comprising hydrogen and a second hydrogenation feed stream comprising olefins to a hydrogenation unit, and hydrogenating the second hydrogenation feed stream over a hydrogenation catalyst under hydrogenation reaction conditions to form a hydrogenation product stream comprising paraffins, wherein the first hydrogenation feed stream and the second hydrogenation feed stream are derived from the first feed stream, and the first hydrogenation feed stream comprises the electrolytic cell product stream. One embodiment of the present invention is one, any or all of the previous embodiments of this paragraph to the third embodiment of this paragraph, wherein the oligomerization reaction conditions include a temperature of 100 °C to 260 °C and a pressure of 2.1 MPa to 8.4 MPa. One embodiment of the present invention is one, any or all of the previous embodiments of this paragraph to the third embodiment of this paragraph, wherein the oligomerization catalyst comprises a zeolite having a ten-ring, one-dimensional pore structure or a metal-supported catalyst. One embodiment of the present invention is one, any or all of the previous embodiments of this paragraph to the third embodiment of this paragraph, wherein the second hydrogenation feed stream comprises the third reaction product stream.

[0085] Although no further detailed description is provided, it is believed that those skilled in the art can utilize the present invention to the greatest extent by using the foregoing description and can readily determine the basic features of the present invention without departing from the essence and scope of the present invention to make various changes and modifications thereto and adapt it to various uses and conditions. Therefore, the foregoing preferred specific embodiments should be understood as merely illustrative and not in any way limiting the remainder of the disclosure, and are intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

[0086] In the foregoing, all temperatures are shown in degrees Celsius and all parts and percentages are by weight unless otherwise indicated.

Claims

1. A method for the hydrogenation of olefins, the method comprising: Providing a first feed stream comprising an oxygenated hydrocarbon 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 electrolytic cell product stream comprising hydrogen, providing a first hydrogenation feed stream comprising hydrogen and a second hydrogenation feed stream comprising olefins to a hydrogenation unit, and Hydrogenating the second hydrogenation feed stream over a hydrogenation catalyst under 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 derived from the first feed stream.

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

3. The method according to claim 1, wherein the first feed stream comprises triglycerides.

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

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

6. The method according to claim 5, wherein the catalyst comprises γ-alumina.

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

8. The method according to claim 1, the method further comprising compressing the electrolytic cell product stream to hydrogenation reaction conditions.

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

10. The method according to claim 1, wherein the first hydrogenation feed stream comprises the electrolytic cell product stream.

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