Method for preparing SAF through continuous hydrogenation of bio-based aviation oil precursor and hydrogenation reactor

Abstract

The invention discloses a method for preparing SAF through continuous hydrogenation of a bio-based aviation oil precursor and a hydrogenation reactor, and belongs to the technical field of preparation of sustainable aviation oil. The hydrogenation reactor comprises a dispersion kettle, a first-stage hydrogenation reaction kettle, a second-stage hydrogenation reaction kettle, a filter, a reaction product cooler, a split-phase tank and a rectifying tower which are sequentially connected in series; the method comprises the following steps: mixing an aviation oil precursor, a supplementary catalyst and a hydrocarbon solvent in a dispersion kettle to obtain a reaction solution, then conveying the reaction solution to a primary hydrogenation reaction kettle for hydrogenation saturation and hydrodeoxygenation reaction, conveying part of unreacted reaction solution to a secondary hydrogenation reaction kettle for hydrogenation saturation and hydrodeoxygenation reaction, and then outputting a reaction product, sequentially passing through a filter and a reaction product cooler to enter a split-phase tank, and separating to obtain an SAF crude product; and inputting the SAF crude product into a rectifying tower, and separating to obtain an SAF product. The production process is continuous, the product quality is stable, and the method is suitable for large-scale production of sustainable aviation oil by hydrogenation of a condensation body prepared from a bio-based platform compound.

Description

Technical Field

[0001] This invention belongs to the field of sustainable aviation fuel preparation technology, specifically relating to a method for preparing SAF from bio-based aviation fuel precursors by continuous hydrogenation and a hydrogenation reactor. Background Technology

[0002] Currently, the American Society for Testing and Materials (ASTM) standard D7566 includes eight preparation routes for SAF (Self-Produced Acid Fermented Oil), mainly categorized as Fischer-Tropsch, oil and fat hydrogenation, alcohol-based aviation fuel, and hydrogenated fermentation sugar-based aviation fuel routes. Biomass aqueous synthesis technology utilizes lignocellulose and hemicellulose from biomass to prepare sugars and their derivatives, such as furfural, through hydrolysis. Subsequently, carbon chains are lengthened through condensation reactions, and the condensation products can be hydrogenated and deoxygenated to prepare C8-C9 series fuels. 15 This method produces aviation fuel hydrocarbons with long-chain alkanes as the main component. While not currently included in the D7566 standard, compared to existing SAF production routes listed in the D7566 standard, the bio-aviation fuel prepared by this method is of high quality and relatively low cost, showing promise for large-scale, stable production.

[0003] Existing bio-based platform compound condensate hydrodeoxygenation technologies mostly employ fixed-bed reactors, as exemplified by patents CN112546968A, CN102850157B, CN103450940B, CN113444543A, CN114891535B, CN112546968A, CN102850157A, and CN107400531. Current hydrogenation technologies primarily separate the hydrogenation saturation and hydrodeoxygenation reactors, resulting in excessively long process flows, high equipment investment, and complex process control.

[0004] Therefore, this invention proposes a production method and hydrogenation reactor for the one-step continuous hydrogenation saturation and hydrogenation deoxygenation of bio-based aviation fuel precursors to prepare sustainable aviation fuel. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a method and hydrogenation reactor for the continuous hydrogenation of bio-based aviation fuel precursors to prepare SAF, thereby solving the problems in the prior art.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A hydrogenation reactor for the continuous hydrogenation of bio-based aviation fuel precursors to produce SAF includes a dispersion vessel, a primary hydrogenation reactor, a secondary hydrogenation reactor, a filter, a reaction product cooler, a phase separation tank, and a distillation column connected in series.

[0008] Aviation fuel precursor, supplementary catalyst, and hydrocarbon solvent are mixed in a dispersion vessel to obtain a reaction solution, which is then transported to a primary hydrogenation reactor for hydrogenation saturation and hydrodeoxygenation reactions. A portion of the unreacted reaction solution is transported to a secondary hydrogenation reactor for hydrogenation saturation and hydrodeoxygenation reactions. The reaction product is then output from the secondary hydrogenation reactor and sequentially passes through a filter and a reaction product cooler before entering a phase separation tank to separate the crude SAF product. The crude SAF product is then fed into a distillation column to separate the SAF product.

[0009] Furthermore, the primary hydrogenation reactor and the secondary hydrogenation reactor have the same structure, both including: a hydrogen distribution ring pipe, a circulation nozzle and a hydrocyclone separator installed inside, and a circulation pump and a cooler installed outside;

[0010] After the reaction liquid in the dispersion vessel is sent to the primary hydrogenation reactor, the circulation pump extracts the reaction liquid and sends it to the cooler for cooling. Then, part of the reaction liquid is sprayed into the primary hydrogenation reactor through the circulation nozzle for reaction. The remaining reaction liquid is separated into solid phase by a hydrocyclone separator and then fed into the secondary hydrogenation reactor.

[0011] In the secondary hydrogenation reactor, the circulating pump draws the reaction liquid out and sends it to the cooler for cooling. Then, part of the reaction liquid is sprayed into the secondary hydrogenation reactor through the circulating nozzle to react; the other part of the reaction liquid is separated into solid phases by a hydrocyclone separator and then output.

[0012] Furthermore, a crude SAF transfer pump is provided on one side of the phase separation tank. The crude SAF transfer pump can input the crude SAF obtained from the phase separation tank into the distillation column, and at the same time pump a portion of the crude SAF into the dispersion vessel as a hydrocarbon solvent.

[0013] Furthermore, the filter has a built-in metal screen or a metal sintered rod filter element.

[0014] Furthermore, the reaction product cooler is a shell-and-tube heat exchanger, which can cool the reaction products to 45-60°C.

[0015] A method for continuously hydrogenating bio-based aviation fuel precursors to prepare SAF, using the aforementioned hydrogenation reactor, includes the following steps:

[0016] S1, add aviation fuel precursor, supplementary catalyst and hydrocarbon solvent to dispersion vessel and mix to obtain reaction solution;

[0017] S2, the reaction liquid is sent into the first-stage hydrogenation reactor, the circulating pump, cooler, circulating nozzle and hydrocyclone are turned on, and hydrogen is sent into the first-stage hydrogenation reactor through the hydrogen distribution ring pipe to mix with the reaction liquid sprayed from the circulating nozzle to carry out hydrogenation saturation and hydrogenation deoxygenation reactions.

[0018] S3, some unreacted reaction liquid is sent to the secondary hydrogenation reactor after passing through the hydrocyclone separator, and the circulating pump, cooler, circulating nozzle and hydrocyclone separator are turned on to carry out hydrogenation saturation and hydrogenation deoxygenation reactions.

[0019] S4, the reaction products output from the secondary hydrogenation reactor are sequentially fed into: a filter, a reaction product cooler and a phase separation tank to separate and obtain crude SAF product;

[0020] S5, start the SAF crude product transfer pump to feed the SAF crude product into the distillation column to separate and obtain the SAF product; and pump a portion of the SAF crude product into the dispersion vessel as a hydrocarbon solvent for recycling.

[0021] Furthermore, the mass ratio of the aviation fuel precursor to the supplementary catalyst is 1:(0.0005~0.001).

[0022] Furthermore, the supplementary catalyst is a mixture of a hydrogenation saturation catalyst and a hydrodeoxygenation isomerization catalyst, wherein the mass ratio of the hydrogenation saturation catalyst to the hydrodeoxygenation isomerization catalyst is 1:1 to 5.

[0023] Furthermore, the hydrogenation saturation catalyst is one of Raney nickel, Ru / C, or Pb / C; the hydrogenation deoxygenation isomerization catalyst is a supported bifunctional catalyst, with the active component being one or more of Pt, Pd, or Ni, and the support being one of γ-Al2O3, SAPO-11, or SiO2.

[0024] Furthermore, the operating temperature of the primary hydrogenation reactor and the secondary hydrogenation reactor is 260–320°C, and the operating pressure is 1.5–4 MPaG.

[0025] The beneficial effects of this invention are:

[0026] 1. This invention proposes a bubbling bed reactor for the continuous hydrogenation saturation and hydrogenation deoxygenation integrated reaction of biomass-based condensed aviation fuel precursors, using biomass-based condensed aviation fuel precursors as raw materials. A hydrocyclone separator is installed inside the reactor to separate the solid catalyst from the reactants, retaining the catalyst within the reactor. A high-flow-rate circulating pump and an external cooler are installed outside the reactor. The built-in hydrocyclone separator can replace traditional solid-liquid separation devices (such as centrifuges and plate and frame filter presses), effectively reducing investment in equipment and instruments, and reducing energy loss and exhaust emissions (as solids inevitably come into contact with ambient air when discharged from the solid-liquid separation device). Furthermore, the built-in hydrocyclone separator ensures continuous system operation, unaffected by the intermittent unloading of traditional solid-liquid separation equipment.

[0027] 2. This invention combines the two-step hydrogenation saturation and hydrodeoxygenation reactions into a single reactor, eliminating the need for a stirrer. An external high-flow-rate circulating pump and an internal jet nozzle ensure thorough mixing of the reactants within the reactor. Heat generated during the reaction is promptly removed via an external tubular heat exchanger. Compared to traditional tubular fixed-bed reactors, this invention's reactor system has no upper limit on heat removal, preventing the risk of temperature runaway. Furthermore, unlike traditional fully mixed-flow reactors, this invention's reactor eliminates the need for a stirrer, avoiding catalyst wear and loss during stirring and extending catalyst lifespan.

[0028] 3. The reactor of this invention is equipped with a hydrogen distribution pipe at the bottom, with uniformly distributed gas holes at the bottom. This allows hydrogen to be introduced into the reaction mixture in the form of uniform bubbles. Combined with the high-flow-rate circulation of the reaction liquid within the reactor, the hydrogen can dissolve better into the solvent and participate in the hydrogenation reaction. Compared to traditional fixed-bed hydrogenation reactions where hydrogen is in excess, this invention can precisely supply hydrogen to the reactor based on hydrogen consumption. Only a small amount of inert gas is extracted from the top of the reactor. Unlike traditional fixed-bed hydrogenation reaction systems, which require a hydrogen adsorption, purification, and recompression device at the reactor outlet due to a large excess of hydrogen, this invention significantly reduces equipment investment and operational complexity. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a continuous production process roadmap of the present invention;

[0031] In the diagram: 1 is a dispersion vessel, 2 is a dispersion transfer pump, 31 is a primary hydrogenation reactor, 32 is a secondary hydrogenation reactor, 41 is a primary circulation pump, 42 is a secondary circulation pump, 51 is a primary cooler, 52 is a secondary cooler, 61 is a primary hydrogen distribution loop, 62 is a secondary hydrogen distribution loop, 71 is a primary circulation nozzle, 72 is a secondary circulation nozzle, 81 is a primary hydrocyclone separator, 82 is a secondary hydrocyclone separator, 9 is a filter, 10 is a reaction product cooler, 11 is a phase separation tank, 12 is a SAF crude product transfer pump, and 13 is a distillation column. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] like Figure 1 As shown, the hydrogenation reactor for the continuous hydrogenation of bio-based aviation fuel precursors to produce SAF includes a dispersion vessel 1, a primary hydrogenation reactor 31, a secondary hydrogenation reactor 32, a filter 9, a reaction product cooler 10, a phase separation tank 11, and a distillation column 13 connected in series. The aviation fuel precursor, supplementary catalyst (solid catalyst), and hydrocarbon solvent are uniformly mixed in the dispersion vessel 1 to obtain a reaction solution, which is then transferred to the primary hydrogenation reactor 31 for hydrogenation saturation and deoxygenation reactions. A portion of the unreacted reaction solution is transferred to the secondary hydrogenation reactor 32 for hydrogenation saturation and deoxygenation reactions. The reaction product then passes sequentially through the filter 9 and the reaction product cooler 10 into the phase separation tank 11, where crude SAF is separated. The crude SAF is then fed into the distillation column 13 for further separation to obtain the final SAF product.

[0034] The primary hydrogenation reactor 31 is equipped with a primary hydrogen distribution loop 61, a primary circulation nozzle 71, and a primary hydrocyclone separator 81. A primary circulation pump 41 and a primary cooler 51 are installed on the outside of the primary hydrogenation reactor 31. After the reaction liquid in the dispersion vessel 1 is fed into the primary hydrogenation reactor 31, the primary circulation pump 41 extracts the reaction liquid and sends it to the primary cooler 51 for cooling. Then, a portion of the reaction liquid is sprayed into the primary hydrogenation reactor 31 through the primary circulation nozzle 71 to undergo hydrogenation saturation and hydrogenation deoxygenation reactions with the hydrogen output from the primary hydrogen distribution loop 61. The remaining reaction liquid, after being separated into solid phases by the primary hydrocyclone separator 81, is fed into the secondary hydrogenation reactor 32.

[0035] It should be noted that most of the reaction products circulate within the primary hydrogenation reactor 31, which serves to turbulent the fluid within the reactor. A small amount of the reaction products are sent to the secondary hydrogenation reactor 32 after passing through the primary hydrocyclone separator 81, where they undergo hydrogenation saturation and hydrogenation deoxygenation reactions together with the reaction liquid.

[0036] The secondary hydrogenation reactor 32 has the same structure as the primary hydrogenation reactor 31. Specifically, the secondary hydrogenation reactor 32 is equipped with a secondary hydrogen distribution loop pipe 62, a secondary circulation nozzle 72, and a secondary hydrocyclone separator 82. A secondary circulation pump 42 and a secondary cooler 52 are installed on the outside of the secondary hydrogenation reactor 32. After the reaction liquid from the primary hydrogenation reactor 31 is sent to the secondary hydrogenation reactor 32, the secondary circulation pump 42 draws the reaction liquid out and sends it to the secondary cooler 52 for cooling. Then, most of the reaction liquid is sprayed into the secondary hydrogenation reactor 32 through the secondary circulation nozzle 72 to undergo hydrogenation saturation and hydrogenation deoxygenation reactions with the hydrogen output from the secondary hydrogen distribution loop pipe 62. A small portion of the reaction liquid is separated into solid phases by the secondary hydrocyclone separator 82 and then output. Furthermore, the reaction products of the secondary hydrogenation reactor 32 are also output through the secondary hydrocyclone separator 82 and sent to the filter 9.

[0037] In this embodiment, a dispersion transfer pump is provided between the dispersion vessel 1 and the primary hydrogenation reactor 31, which can pump the reaction liquid in the dispersion vessel 1 into the primary hydrogenation reactor 31.

[0038] In this embodiment, the hydrocarbon solvent is crude SAF; and a crude SAF transfer pump 12 is provided on one side of the phase separation tank 11. The crude SAF transfer pump 12 can input the crude SAF obtained from the phase separation tank 11 into the distillation column 13, and can also send the crude SAF into the dispersion vessel 1 as a hydrocarbon solvent to realize the recycling of the solvent.

[0039] The method for preparing SAF products using the above-mentioned hydrogenation reactor specifically includes the following steps:

[0040] S1. The aviation fuel precursor was prepared using a conventional bio-based platform molecular method. The specific steps are as follows: In an aqueous phase, under the catalysis of an alkaline substance, biomass-based furfural derivatives and biomass-based levulinic acid and its derivatives underwent an aldol condensation reaction to obtain a condensation solution (C). 10 ~C 20 (Oxygen-containing compounds); The condensation reaction conditions are: 20-80℃, 0.2-0.5MPaA; 8wt% sulfuric acid aqueous solution is added to the condensation liquid to adjust the pH of the condensation liquid to 3-5, resulting in a suspended precipitate; Solid-liquid separation is performed through the condensation liquid filter to obtain the condensation intermediate solid and mother liquor, and the mother liquor is returned to prepare the 8% sulfuric acid aqueous solution; Then the condensation intermediate solid (aviation fuel precursor) is sent to a drying oven to dry and dehydrate at 100-200℃ to ensure that the moisture content in the dried solid material is ≤2wt%;

[0041] S2, the dried and dehydrated condensation intermediate (aviation fuel precursor) and the mixed supplementary catalyst (solid catalyst) are continuously and quantitatively added to the dispersion vessel 1 through a feeding hopper. At the same time, crude SAF (hydrocarbon solvent) is continuously and quantitatively added to the dispersion vessel 1 through crude SAF transfer pump 12. In the dispersion vessel 1, the condensation intermediate and solid catalyst are uniformly dispersed in the crude hydrocarbon SAF solvent by a high-speed stirrer to obtain a reaction solution. The solid catalyst is a mixture of hydrogenation saturated catalyst and hydrodeoxygenation isomerization catalyst, and the mass ratio of the catalyst is: hydrogenation saturated catalyst: hydrodeoxygenation isomerization catalyst is 1:1 to 5. The mass ratio of each material added to the dispersion vessel 1 is: condensation intermediate: supplementary catalyst: hydrocarbon solvent is 1:0.0005 to 0.001:3 to 20.

[0042] S3, the condensation intermediate dispersion solution (reaction liquid) is continuously added to the primary hydrogenation reactor 31 through the dispersion delivery pump 2. High-pressure hydrogen gas is uniformly injected into the primary hydrogenation reactor 31 through the small holes of the primary hydrogen distribution ring pipe 61 at the bottom. The primary circulation pump 41 extracts the material in the reactor and sends it to the primary cooler 51. Most of the cooled reaction mixture is re-injected into the reactor through the primary circulation nozzle 71. A small amount of the reaction mixture enters the two-stage series primary hydrocyclone separator 81 in the reactor. In the hydrocyclone separator, the solid catalyst and the reaction liquid undergo solid-liquid separation. The reaction liquid after solid separation enters the secondary hydrogenation reactor 32. The mass ratio of the reaction liquid entering the primary circulation nozzle 71 to the material entering the primary hydrocyclone separator 81 is 1:0.01~0.1. The operating temperature of the primary hydrogenation reactor is 150~320℃, and the operating pressure is 1.5~4MPaG. It should be noted that the solid catalyst is added to the reactor in a measured amount before starting the reactor. During normal reaction, the catalyst is retained in the reactor by a hydrocyclone separator. The small amount of catalyst loss is replenished by adding fresh raw materials.

[0043] The operating procedures and conditions of the secondary hydrogenation reactor 32 (S4) are the same as those of the primary hydrogenation reactor.

[0044] S5, the discharge from the secondary hydrogenation reactor 32 enters the filter 9. The filter 9 has a built-in metal screen or metal sintered rod filter element to separate the small amount of solid catalyst entrained. Then the reaction product enters the reaction product cooler 10 to cool the reaction product to 45-60°C and then enters the phase separation tank 11. Liquid-liquid phase separation is carried out in the phase separation tank 11. The aqueous phase generated by the reaction is in the lower layer and the oil phase is in the upper layer. Through the built-in baffle of the phase separation tank 11, the upper oil phase overflows to the other side of the phase separation tank baffle. The oil phase product (SAF crude product) is continuously sent to the distillation column 13 through the SAF crude product transfer pump 12. The phase separation tank operates at a temperature of 45-60°C and an operating pressure of atmospheric pressure.

[0045] S6. The SAF crude product delivered by the SAF crude product transfer pump 12 is separated into oil products through the distillation column 13. Naphtha is obtained from the top of the column, sustainable aviation fuel SAF product is obtained from the upper side stream in the middle of the column, and biodiesel is obtained from the bottom of the column. The distillation column is a packed column with a top operating temperature of 30-100℃, a side stream outlet temperature of 130-280℃, a bottom temperature of 260-370℃, and an operating pressure of -0.06-0.02 MPaG. The mass of aviation fuel collected from the side stream is 0.88-0.96 of the feed amount of the distillation column, the mass of naphtha collected from the top of the column is 0.02-0.06 of the feed amount of the distillation column, and the mass of biodiesel collected from the bottom of the column is 0.02-0.06 of the feed amount of the distillation column.

[0046] In S1, the biomass-based furfural derivative is: hemicellulose, biomass-based furfural derivatives after dehydration and hydrolysis of cellulose (5-hydroxymethylfurfural, furfural, etc.); the biomass-based levulinic acid is: levulinic acid prepared by acid-catalyzed hydrolysis of cellulose as raw material, and the derivative of biomass-based levulinic acid is: levulinic acid esters generated by levulinic acid esterification (such as: methyl levulinate, ethyl levulinate, etc.).

[0047] In S1, the aldol condensation reaction is carried out in a conventional stirred reactor; the catalyst for the aldol condensation reaction is NaOH or KOH, and the catalyst concentration in the aldol condensation reaction solution is 1.1 to 1.5 wt%.

[0048] In S2, the solid feeding hopper is a quantitative continuous feeding hopper with a rotary feeding valve; the hydrogenation saturated catalyst is one of Raney nickel, Ru / C or Pb / C; the hydrogenation deoxygenation isomer catalyst is a supported bifunctional catalyst, the active component is one or more of Pt, Pd or Ni, and the support is one of γ-Al2O3, SAPO-11 or SiO2.

[0049] Further, the mass ratio of each material added to the dispersion vessel 1 is as follows: the condensation intermediate (aviation fuel precursor): supplementary catalyst: hydrocarbon solvent is 1:0.0005~0.001:3~20; the supplementary catalyst is a mixture of hydrogenation saturated catalyst and hydrogenation deoxygenation isomerization catalyst, and the ratio of hydrogenation saturated catalyst: hydrogenation deoxygenation isomerization catalyst is 1:1~5.

[0050] In S3, the flow rate of the primary circulating pump 41 is 50 to 300 times (by mass) the feed flow rate of the primary hydrogenation reactor, and the pump head is 40 to 80 m; the external circulation flow rate (flow rate entering the primary circulating nozzle 71) of the primary hydrogenation reactor 31 is 10 to 100 times (by mass) the inlet flow rate of the primary hydrocyclone separator 81; the operating temperature of the primary hydrogenation reactor is 150 to 320°C, and the operating pressure is 1.5 to 4 MPaG.

[0051] Preferably, in S3, the flow rate of the primary circulating pump 41 is 100 to 200 times (by mass) the feed to the reactor, and the pump head is 60 to 70 m; the external circulation flow rate of the primary hydrogenation reactor 31 is 40 to 80 times (by mass) the inlet flow rate of the hydrocyclone separator; the operating temperature of the reactor is 250 to 300°C, the operating pressure is 2 to 3 MPaG, and the material residence time in the reactor is 1.5 to 2.5 h.

[0052] Preferably, in step S5, the filter 9 is a filter with a built-in metal sintered rod filter element and a filtration accuracy of 1-10 μm; the reaction product cooler 10 is a shell-and-tube heat exchanger that cools the reaction product to 50-55°C; the phase separation tank 11 is a phase separation tank with a built-in baffle that separates the water and oil phases by density difference, and the residence time of the oil and water phase materials in the phase separation tank is 2-4 hours to ensure the phase separation effect.

[0053] In S6, the distillation column 13 is a packed column with side stream output, and the packing is random packing or structured packing with 3 to 6 packing sections.

[0054] The invention is further illustrated below through the following examples, but not as a limitation thereof. The examples detail the process using a condensation intermediate obtained by aldol condensation of commercially available 98 wt% furfural and 99 wt% levulinic acid as raw materials. Unless otherwise specified, the equipment and chemicals used in this invention are commercially available products conventional in this technical field.

[0055] Example 1

[0056] 1) Commercially available 98wt% furfural, 99wt% levulinic acid, 5wt% sodium hydroxide and water are introduced into a jacketed stainless steel reactor. Cooling circulating water is circulated in the jacket. After 2 hours of reaction, aldol condensate is obtained. Then, 8wt% sulfuric acid is added dropwise to the reactor to adjust the pH to 3-4. The aldol condensate intermediate becomes a solid and precipitates from the aqueous solution. After centrifugation, the water content of the aldol condensate intermediate is dried to ≤2wt% in a vacuum drying oven at 60-100℃.

[0057] 2) The hydrogenation saturated catalyst is commercially available Raney nickel powder; the preparation method of the hydrodeoxygenation isomerization catalyst is as follows:

[0058] ① Sodium silicate, ammonium salt and demineralized water are uniformly mixed in a stirring vessel to form a gel, resulting in colloidal substance A; preferably, the mixing conditions are: normal pressure, room temperature and stirring for 6 hours;

[0059] ②Tetraethoxytitanium dissolves in a mixed solvent of ethanol, acetic acid and desalinated water to obtain colloidal substance B;

[0060] ③ Slowly add phosphoric acid to demineralized water, then add boehmite and stir for 3 hours, then add silica sol and stir for 1.5 hours, then add template agent and crystallize for 48 hours at a crystallization temperature of 190℃. After crystallization, cool the product to room temperature. The solid obtained by filtering the product is washed with demineralized water until neutral, and then dried, calcined and pulverized to obtain SAPO-31 carrier.

[0061] ④ The colloidal substance A obtained in step ①, the colloidal substance B obtained in step ②, and the SAPO-31 support obtained in step ③ are stirred and mixed at 60°C for 6 hours under nitrogen sealing conditions, then filtered. The resulting filter cake is dried in a desiccator at normal pressure and 140°C for 20 hours. The dried filter cake is then calcined in air at normal pressure and 550°C for 8 hours. The resulting solid is then pulverized to obtain a composite support of composite oxide + SAPO-31.

[0062] ⑤ The particle size d of the carrier obtained in step ④ is controlled during pulverization. 50 =100μm as the catalyst support, nickel salt is dissolved in water to prepare a nickel salt aqueous solution, and then the catalyst support is added to the nickel salt aqueous solution for 6 hours, followed by drying and calcination to obtain the hydrodeoxygenation isomer catalyst for SAF aviation fuel production.

[0063] In this embodiment, the mass ratio of the hydrogenation saturation catalyst and the hydrogenation deoxygenation isomerization catalyst is 1:3.5.

[0064] 3) The condensation intermediate prepared in step 1) and the mixed catalyst prepared in step 2) are continuously fed into the dispersion vessel 1 via a solid quantitative continuous feeding system. The feed rate of the condensation intermediate is 10 kg / h, and the feed rate of the mixed catalyst is 0.008 kg / h. Simultaneously, recycled SAF aviation fuel crude is continuously fed into the dispersion vessel 1 via the SAF crude product transfer pump 12 at a rate of 100 kg / h. Inside the dispersion vessel 1, the condensation intermediate and the catalyst form a homogeneous dispersion through the dispersion action of the stirrer. The dispersion vessel 1 operates at atmospheric pressure and temperature.

[0065] 4) The dispersion obtained in step 3) is pressurized by dispersion delivery pump 2 and continuously fed to a two-stage hydrogenation reactor connected in series. The two-stage reactors are connected in series to ensure the reaction residence time. By controlling the amount of hydrogen added, the reaction rate is controlled to prevent the reaction from concentrating in the first-stage hydrogenation reactor 31, which would result in excessive heat release. The hydrogen feed rate to the first-stage hydrogenation reactor 31 is controlled at 7.7 Nm³. 3 / h, the hydrogen feed rate in the secondary hydrogenation reactor 32 is controlled at 3.3 Nm³. 3 / h. The two-stage hydrogenation reactors are connected in gas phase. The first-stage hydrogenation reactor 31 operates at a temperature of 260℃ and a pressure of 2 MPaG, while the second-stage hydrogenation reactor 32 operates at a temperature of 300℃ and a pressure of 2 MPaG. The first-stage circulating pump has a flow rate of 11 m³ / h. 3The material flow rate entering the first-stage hydrocyclone separator 81 is 1 m³ / h. 3 / h. Secondary circulating pump flow rate 10m³ / h. 3 The material flow rate entering the secondary hydrocyclone separator is 1 m³ / h. 3 / h.

[0066] 5) The liquid phase outlet rate of the secondary hydrocyclone 82 is 110.37 kg / h. The detected alkane content is 96.97 wt% and the water content is 3.03 wt%. After being cooled to 45°C by the reaction product cooler 10, the reaction product enters the phase separation tank 11. Most of the water is separated from the reaction product in the phase separation tank 11. The operating conditions of the phase separation tank 11 are: 45°C, 0.002 MPaG. After the water is separated by the phase separation tank, part of the oil phase product is sent to the dispersion vessel 1 by the SAF crude product transfer pump 12 at a flow rate of 100 kg / h, and the other part is sent to the distillation column 13 at a flow rate of 7.03 kg / h.

[0067] 6) The distillation column 13 has a total of 4 packing layers, each 1m high. Feed is fed between the 3rd and 4th packing sections of the distillation column 13 (counting from top to bottom). 0.14kg / h of light naphtha is collected from the top of the column, 0.14kg / h of heavy diesel is collected from the bottom of the column, and 6.75kg / h of aviation fuel is collected from the side stream below the 1st packing section.

[0068] Example 2

[0069] The implementation steps of this embodiment are the same as in Embodiment 1, except that the ratio of the hydrogenation saturated catalyst to the hydrodeoxygenation isomerization catalyst is changed. The results are shown in Table 1 below:

[0070] Table 1. Product Yields for Different Catalyst Ratios

[0071]

[0072] Example 3

[0073] The implementation steps of this embodiment are the same as in Embodiment 1, except that the feed ratio of the condensation intermediate (aviation fuel precursor) and the catalyst is changed. The results are shown in Table 2 below:

[0074] Table 2. Product Yields Corresponding to Different Raw Material and Catalyst Ratios

[0075]

[0076] Example 4

[0077] The implementation steps of this embodiment are the same as in Embodiment 1, only the operating conditions of the primary and secondary hydrogenation reactors are changed. The results are shown in Table 3 below:

[0078] Table 3. Product Yields at Different Reaction Temperatures

[0079]

[0080] Example 5

[0081] The implementation steps of this embodiment are the same as in Embodiment 1, only the operating conditions of the primary and secondary hydrogenation reactors are changed. The results are shown in Table 4 below:

[0082] Table 4. Product Yields for Different Reaction Pressures

[0083]

[0084]

[0085] Based on the product yields shown in Tables 1-4, it can be seen that:

[0086] 1. The ratio of hydrogenation saturated catalyst to hydrodeoxygenation isomerization catalyst has a significant impact on product yield. The amount of hydrodeoxygenation isomerization catalyst added should exceed that of hydrogenation saturated catalyst by 3.5 times to obtain the theoretical aviation fuel yield.

[0087] 2. The mass ratio of condensation intermediate to catalyst has a significant impact on product yield; insufficient catalyst quantity will lead to a decrease in product yield.

[0088] 3. The temperature of the hydrogenation reactor is quite sensitive to the product yield; the suitable reaction temperature is above 260℃.

[0089] 4. The pressure in the hydrogenation reactor is not sensitive to the product yield.

[0090] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0091] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. Hydrogenation reactor for the continuous hydrogenation of a bio-based jet fuel precursor to produce SAF, characterized in that, The dispersion kettle, the first-stage hydrogenation reaction kettle, the second-stage hydrogenation reaction kettle, the filter, the reaction product cooler, the phase separation tank and the rectifying tower are connected in series. The aviation fuel precursor, the supplementary catalyst and the hydrocarbon solvent are mixed in the dispersion kettle to obtain a reaction liquid, which is then sent to the first-stage hydrogenation reaction kettle to perform hydrogenation saturation and hydrogenation deoxidation reaction, and part of the unreacted reaction liquid is sent to the second-stage hydrogenation reaction kettle to perform hydrogenation saturation and hydrogenation deoxidation reaction, and then the reaction product of the second-stage hydrogenation reaction kettle is sent to the filter, the reaction product cooler and the phase separation tank in sequence to obtain the SAF crude product.

2. The hydrogenation reactor for the continuous hydrogenation of a bio-based jet fuel precursor to produce SAF according to claim 1, characterized in that, The first-stage hydrogenation reaction kettle and the second-stage hydrogenation reaction kettle have the same structure, and each comprises a hydrogen distribution ring pipe, a circulating nozzle and a hydrocyclone arranged inside, and a circulating pump and a cooler arranged outside. After the reaction liquid in the dispersion kettle is sent to the first-stage hydrogenation reaction kettle, the circulating pump pumps the reaction liquid out and sends it to the cooler to be cooled, and then part of the reaction liquid is sprayed into the first-stage hydrogenation reaction kettle through the circulating nozzle to react. In the second-stage hydrogenation reaction kettle, the circulating pump pumps the reaction liquid out and sends it to the cooler to be cooled, and then part of the reaction liquid is sprayed into the second-stage hydrogenation reaction kettle through the circulating nozzle to react, and the other part of the reaction liquid is separated from the solid phase by the hydrocyclone and then output.

3. The hydrogenation reactor for the continuous hydrogenation of a bio-based jet fuel precursor to produce SAF according to claim 2, characterized in that, The phase separation tank is provided with a SAF crude product conveying pump on one side, which can send the SAF crude product separated from the phase separation tank into the rectifying tower, and pump part of the SAF crude product into the dispersion kettle as the hydrocarbon solvent.

4. The hydrogenation reactor for the continuous hydrogenation of a bio-based jet fuel precursor to produce SAF according to claim 1, characterized in that, The filter is provided with a metal screen or a metal sintered rod filter element.

5. The hydrogenation reactor for the continuous hydrogenation of a bio-based jet fuel precursor to produce SAF according to claim 1, characterized in that, The reaction product cooler is a tube-shell heat exchanger, which can cool the reaction product to 45-60℃.

6. Process for the continuous hydrogenation of a bio-based jet fuel precursor to produce SAF, using the hydrogenation reactor according to any one of claims 3, characterized in that, The method comprises the following steps: S1, the aviation fuel precursor, the supplementary catalyst and the hydrocarbon solvent are added to the dispersion kettle to obtain a reaction liquid; S2, the reaction liquid is sent to the first-stage hydrogenation reaction kettle, and the circulating pump, the cooler, the circulating nozzle and the hydrocyclone are started, and hydrogen is sent to the first-stage hydrogenation reaction kettle through the hydrogen distribution ring pipe to mix with the reaction liquid sprayed by the circulating nozzle to perform hydrogenation saturation and hydrogenation deoxidation reaction; S3, part of the unreacted reaction liquid is sent to the second-stage hydrogenation reaction kettle after being separated from the solid phase by the hydrocyclone, and the circulating pump, the cooler, the circulating nozzle and the hydrocyclone are started to perform hydrogenation saturation and hydrogenation deoxidation reaction; S4, the reaction product output from the second-stage hydrogenation reaction kettle is sent to the filter, the reaction product cooler and the phase separation tank in sequence to obtain the SAF crude product; S5, the SAF crude product conveying pump is started to send the SAF crude product into the rectifying tower to obtain the SAF product, and part of the SAF crude product is pumped into the dispersion kettle as the hydrocarbon solvent for recycling.

7. The method of continuously hydroprocessing a bio-based jet fuel precursor to produce SAF according to claim 6, wherein, The mass ratio of the aviation fuel precursor to the supplementary catalyst is 1:(0.0005-0.001).

8. The method of continuously hydroprocessing a bio-based jet fuel precursor to produce SAF according to claim 6, wherein, The supplementary catalyst is a mixture of hydrogenation saturation catalyst and hydrogenation deoxidation isomerization catalyst, and the mass ratio of the hydrogenation saturation catalyst to the hydrogenation deoxidation isomerization catalyst is 1:1-5.

9. The method of continuously hydroprocessing a bio-based jet fuel precursor to produce SAF according to claim 6 or 8, characterized in that, The hydrogenation saturation catalyst is one of Raney nickel, Ru / C or Pb / C; the hydrogenation deoxidization and isomerization catalyst is a supported bifunctional catalyst, the active component is one or more of Pt, Pd or Ni, and the carrier is one of γ-Al2O3, SAPO-11 or SiO2.

10. The method of continuously hydroprocessing a bio-based jet fuel precursor to produce SAF according to claim 6, wherein, The operating temperature of the primary hydrogenation reactor and the secondary hydrogenation reactor is 260-320 ℃, and the operating pressure is 1.5-4 MPaG.

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