Long-life bio-oil hydro-upgrading multi-level pore catalyst and application

Abstract

The application discloses a long-life bio-oil hydro-upgrading multi-level pore catalyst and application, and belongs to the technical field of biomass energy. In order to realize long-periodic and efficient directional conversion of bio-oil into gasoline and diesel aviation oil, the application provides a bio-oil hydro-upgrading multi-level pore catalyst, and a preparation method thereof comprises the following steps: taking zeolite as a crystal seed, taking tetraethyl orthosilicate as a silicon source, and preparing blocky zeolite through a crystal seed method and a self-assembly technology; the zeolite is sequentially prepared in alkali and acid to create intracrystalline mesopores, and a catalyst carrier is prepared; and then, metal is impregnated on the carrier to prepare the catalyst. The application utilizes a crystal seed method limited crystallization technology to construct zeolite nanosheet interlamellar macropores, utilizes alkali / acid impregnation technology to build intracrystalline mesopore channels, forms the carrier and the catalyst with blocky macroscopic morphology and large-mesopore-micropore multi-level pore structure, and has the advantages of self-forming, high strength, high activity and the like; the service life of the catalyst is prolonged by 5-6 times compared with that of a commercial zeolite-based catalyst, the macroscopic morphology can be reshaped, and the catalyst is beneficial to large-scale production.

Description

Technical Field

[0001] This invention belongs to the field of biomass energy technology, specifically relating to a long-life bio-oil hydrogenation and upgrading multi-level porous catalyst and its application. Background Technology

[0002] my country's annual output of waste straw reaches as high as 865 million tons. As a typical type of biomass-based bulk organic solid waste, straw is characterized by its large quantity, wide distribution, and difficulty in disposal. Open burning and field stockpiling cause serious pollution to the atmosphere, groundwater, and soil, resulting in multi-source, complex, and persistent environmental pollution. At the same time, straw biomass is an internationally recognized zero-carbon renewable energy source with the potential for large-scale replacement of fossil fuels and carbon reduction. Life cycle assessment analysis shows that converting 1 ton of straw into energy can reduce emissions by 1000–1500 kg of CO2 equivalent, 3–15 kg of SO2 equivalent, and 6–7 kg of C2H6 equivalent. Therefore, under my country's dual carbon targets, developing straw-based gasoline / diesel / aviation fuel technologies can achieve synergistic effects of large-scale fossil fuel substitution and pollution and carbon reduction.

[0003] Large-scale development of biofuel production processes based on waste lignocellulosic biomass resources is of great significance for reducing the world's dependence on crude oil and mitigating the impacts of climate change and the environment^(1). 200 billion tons of biomass annually is equivalent to 630 billion barrels of oil, which could reduce carbon dioxide emissions by up to 222 billion tons^(3,4). However, to obtain high-energy-density biofuels, the oxygen content (up to 60 wt%) in biomass bio-oils must be removed, preferably through hydrogen deoxygenation (HDO)^(5,6). Therefore, high HDO catalytic activity of bio-oils is essential, posing a significant challenge to any catalyst.

[0004] Rapid pyrolysis technology uses ultra-high heating rates and ultra-short product residence times to rapidly break down cellulose, hemicellulose, and lignin in biomass into short-chain molecules, yielding over 80% of the energy from the primary material and achieving a bio-oil yield of up to 70%. It has been recognized by the International Energy Agency as the most promising method for large-scale biofuel production. However, bio-oil has a high oxygen content, a low H / C ratio, and an energy density approximately 42% that of fossil fuels. Compared to traditional hydrocarbon fuels such as gasoline and diesel, it differs significantly in properties and requires further hydrodeoxygenation for upgrading.

[0005] Zeolite molecular sieve catalysts possess large specific surface areas, well-developed microporous channels, and adjustable acidity, exhibiting excellent catalytic activity, unique shape selectivity, and relatively low cost. They have achieved commercial synthesis and are widely used in traditional petrochemical industries, and are currently extensively applied in the research of hydrodeoxygenation of bio-oils. However, bio-oils are complex in composition and have poor stability. When hydrogenation temperatures exceed 80°C, intense polymerization reactions occur, and bio-oil enters the pores of the zeolite catalyst, resulting in severe mass and heat transfer, covering the active sites of the catalyst, and leading to catalyst deactivation. While the typical and unique microporous channels of zeolites exhibit excellent shape selectivity in catalytic reactions, their relatively small size (<2.0 nm) severely affects the diffusion of reactants and products, leading to rapid coking during the hydrodeoxygenation of complex bio-oil feedstock systems. As disclosed in CN104624225A, a catalyst and its preparation method for the hydrodeoxygenation of lignin-phenol derivatives in a low-temperature aqueous phase are unfavorable for the diffusion and conversion of large molecular reactants.

[0006] To overcome the aforementioned problems, CN115814842A discloses a catalyst support and catalyst for the hydrodeoxygenation of bio-oil and its application. This method uses a seed crystal method and self-assembly technology to prepare a blocky zeolite molecular sieve support and catalyst, giving the catalyst macropores and intrinsic zeolite micropore channels. While this method addresses the problems to some extent, and the catalyst exhibits good conversion and deoxygenation rates in the initial stages of the reaction, the rapid mass transfer through the macropores in the later stages leads to the rapid carbon deposition on the micropore active centers, resulting in catalyst coking and deactivation, a short lifespan, and difficulty in practical application. Therefore, there is an urgent need to develop a long-life bio-oil hydrodeoxygenation catalyst that leverages the synergistic effect of the macropore-mesopore-micropore hierarchical pore structure of the zeolite molecular sieve catalyst to improve the efficiency of the bio-oil hydrodeoxygenation reaction, reduce carbon deposition in the catalyst channels, and extend the lifespan of the zeolite molecular sieve catalyst. Summary of the Invention

[0007] To address the technical problems in existing zeolite catalysts, such as low directional conversion efficiency due to narrow channels, catalyst coking and deactivation, and short lifespan, this invention develops a zeolite support and uses it to prepare a long-life bio-oil hydrotreating multi-level porous catalyst, achieving long-cycle, directional, and efficient conversion of biomass into gasoline, diesel, and aviation fuel components.

[0008] This invention provides a long-life bio-oil hydrotreating and upgrading hierarchical porous catalyst, the preparation method of which includes the following steps:

[0009] A. Mix tetraethyl orthosilicate, aluminum source, zeolite seed crystals, alkali, alcohol and water evenly to obtain aluminosilicate gel;

[0010] B. The aluminosilicate gel obtained in step A is subjected to a hydrothermal crystallization reaction. After the hydrothermal reaction is completed, it is washed until neutral to obtain blocky zeolite.

[0011] C. The blocky zeolite obtained in step B is first treated with an alkaline solution, then with an acid solution, and then washed and dried to obtain mesoporous blocky zeolite.

[0012] D. The mesoporous block zeolite obtained in step C is placed in an ammonium salt aqueous solution for ion exchange, and then washed, dried and calcined to obtain a long-life bio-oil hydrogenation and upgrading multi-level porous catalyst support.

[0013] E. The support obtained in step D is impregnated in an aqueous solution of metal salt, and then dried and calcined to obtain a long-life bio-oil hydrogenation and upgrading multi-level porous catalyst.

[0014] In step A, the molar ratio of silicon (SiO2) to aluminum (Al2O3) in the obtained aluminosilicate gel is 30–200.

[0015] In step A above, the aluminum source is at least one of water-soluble inorganic aluminum salts, organic aluminum salts, or aluminum complexes.

[0016] Preferably, in step A above, the aluminum source is at least one of sodium aluminate, aluminum sulfate, aluminum nitrate, boehmite, potassium aluminate, and aluminum chloride.

[0017] In step A above, the zeolite seed crystal is at least one of ZSM-5, Beta, MOR, Y-type, and X-type.

[0018] In step A above, the alkali is at least one of inorganic water-soluble sodium or potassium alkali.

[0019] Preferably, in step A above, the alkali is at least one of sodium hydroxide, sodium bicarbonate, sodium carbonate, sodium aluminate, potassium hydroxide, potassium bicarbonate, potassium carbonate, and potassium aluminate.

[0020] In step A above, the alcohol is at least one of methanol, ethanol, n-butanol, and isopropanol.

[0021] In step A above, the molar ratio of silicon (SiO2) to aluminum (Al2O3) in the obtained aluminosilicate gel is 30–200, the molar ratio of sodium and potassium (Na2O and K2O) to silicon (SiO2) is 0.05–5.0, the molar ratio of H2O to silicon (SiO2) is 10–100, the molar ratio of alcohol to silicon (SiO2) is 0.5–2.0, and the mass ratio of zeolite seed crystals to silicon (SiO2) is 0.01–0.2.

[0022] In step A above, the method for achieving uniform mixing is as follows: first, dissolve the aluminum source and alkali in water, then add tetraethyl orthosilicate and alcohol dropwise, stir until uniform, and finally add zeolite seed crystals and continue stirring for 0.5 to 24 hours.

[0023] In step B above, the temperature of the hydrothermal crystallization reaction is 90–200°C.

[0024] Preferably, in step B above, the temperature of the hydrothermal crystallization reaction is 170–200°C.

[0025] In step B above, the hydrothermal crystallization reaction takes 24 to 72 hours.

[0026] Preferably, in step B above, the hydrothermal crystallization reaction takes 24 to 48 hours.

[0027] In step C above, the alkali in the alkaline solution is at least one of sodium hydroxide and potassium hydroxide.

[0028] In step C above, the concentration of the alkaline solution is 0.1–0.5 mol / L.

[0029] In step C above, the ratio of the volume of the alkaline solution to the mass of the blocky zeolite obtained in step B is 15-60 mL: 1 g.

[0030] In step C above, the temperature of the alkaline solution treatment is 60–80°C.

[0031] In step C above, the alkaline solution treatment time is 0.5 to 6 hours.

[0032] Preferably, in step C above, the alkaline solution treatment time is 1.0 to 2.0 hours.

[0033] In step C above, the acid solution is at least one of hydrochloric acid and hydrofluoric acid.

[0034] In step C above, the concentration of the acid solution is 0.1–0.5 mol / L.

[0035] In step C above, the ratio of the volume of the acid solution to the mass of the solid after treatment with the alkali solution is 50-100 mL: 1 g.

[0036] In step C above, the temperature of the acid solution treatment is 60–80°C.

[0037] In step C above, the acid solution treatment time is 0.5 to 6 hours.

[0038] In step D above, the ammonium salt is at least one of ammonium chloride, ammonium nitrate, and ammonium sulfate.

[0039] In step D above, the concentration of the ammonium salt aqueous solution is 0.2–2 mol / L.

[0040] In step D above, the ratio of the volume of the ammonium salt aqueous solution to the mass of the block zeolite is 20-40 mL / g.

[0041] In step D above, the temperature of the ion exchange is 50–100°C.

[0042] In step D above, the ion exchange time is 2 to 24 hours.

[0043] In step D above, the drying temperature is 80-105℃.

[0044] In step D above, the calcination temperature is 300–500°C.

[0045] In step D above, the calcination time is 2 to 6 hours.

[0046] In step D above, step C needs to be repeated 2 to 4 times.

[0047] In step E above, the concentration of the metal salt aqueous solution is 0.01 to 0.05 g / mL.

[0048] In step E above, the metal in the aqueous solution of the metal salt is at least one of V, Cr, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, W, Pt, Au, La, and Ce.

[0049] In step E above, the amount of the metal salt aqueous solution is controlled so that the mass ratio of metal to carrier in the metal salt aqueous solution is 0.4 to 20 wt%.

[0050] In step E above, the immersion temperature is 50–100°C.

[0051] In step E above, the soaking time is 2 to 24 hours.

[0052] In step E above, the drying temperature is 80-105°C.

[0053] In step E above, the calcination temperature is 300–500°C.

[0054] In step E above, the calcination time is 1 to 5 hours.

[0055] The long-life bio-oil hydrogenation and upgrading multi-level porous catalyst support obtained in step D is in block form, with a diameter of 0.5–5 cm and a thickness of 0.2–3 cm.

[0056] The specific surface area of ​​the long-life bio-oil hydrotreating hierarchical porous catalyst obtained in step E above is 50–200 m². 2 / g, total pore volume is 0.01~0.1cm³ 3 / g.

[0057] This invention also provides the application of the above-mentioned long-life bio-oil hydrotreating hierarchical porous catalyst in the production of gasoline, diesel and / or jet fuel from bio-oil.

[0058] The beneficial effects of this invention are:

[0059] This invention utilizes crystal confinement crystallization self-assembly technology to create macroporous channels between nanosheet crystals, and combines alkali / acid leaching technology to build intracrystalline mesoporous channels, thereby achieving the self-assembly and formation of zeolite nanosheet crystal aggregates: (1) Zeolite nanosheet crystals grow along the aluminosilicate framework during hydrothermal processes, forming macroporous channels between nanosheets. These macroporous channels facilitate high-speed mass transfer of macromolecular bio-oils; (2) Zeolite nanosheets form intracrystalline mesopores during alkali-acid treatment. These mesopores serve as transitional channels between macroporous high-speed mass transfer channels and microporous active centers, which facilitates the breaking of long-chain macromolecules from macroporous mass transfer into short-chain small molecules, allowing them to enter the microporous active centers for efficient hydrogenation and deoxygenation reactions; (3) The multi-level pore structure of macropore-mesopore-micropore synergistically promotes reaction efficiency, reduces carbon buildup in catalyst pores, and extends lifespan; (4) The multi-level pore catalyst of this invention has a lifespan extended by 5-6 times, which is superior to micro-macroporous zeolite-based catalysts. Attached Figure Description

[0060] Figure 1 This is a macroscopic morphology diagram of the blocky zeolite NaZSM-5 of the present invention.

[0061] Figure 2 The images show the microstructure of catalysts 10Ni / HZSM-5 and 10Ni / HZSM-5-meso.

[0062] Figure 3 The macropore size distribution diagrams are shown for catalyst 10Ni / HZSM-5 and catalyst 10Ni / HZSM-5-used after 11 hours of operation, and catalyst 10Ni / HZSM-5-meso and catalyst 10Ni / HZSM-5-meso-used after 63 hours of operation.

[0063] Figure 4 The micropore and mesopore size distributions of catalyst 10Ni / HZSM-5 and catalyst 10Ni / HZSM-5-used after 11 h of operation, and catalyst 10Ni / HZSM-5-meso and catalyst 10Ni / HZSM-5-meso-used after 63 h of operation are shown.

[0064] Figure 5The graph shows the cyclohexane adsorption rates of catalysts 10Ni / HZSM-5 and 10Ni / HZSM-5-meso.

[0065] Figure 6 The lifetime evaluation diagrams are for catalysts 10Ni / HZSM-5 and 10Ni / HZSM-5-meso.

[0066] Figure 7 The cyclohexane selectivity diagrams are for catalysts 10Ni / HZSM-5 and 10Ni / HZSM-5-meso.

[0067] Figure 8 XRD patterns of catalyst 10Ni / HZSM-5 and catalyst 10Ni / HZSM-5-used after 11 h of operation, catalyst 10Ni / HZSM-5-meso and catalyst 10Ni / HZSM-5-meso-used after 63 h of operation.

[0068] Figure 9 The TG-DTG diagrams of catalyst 10Ni / HZSM-5-used after 11 hours of operation and catalyst 10Ni / HZSM-5-meso-used after 63 hours of operation are shown in air atmosphere.

[0069] Figure 10 The SEM microstructure and EDS surface element distribution of catalyst 10Ni / HZSM-5-used after 11 h of operation and catalyst 10Ni / HZSM-5-meso-used after 63 h of operation are shown.

[0070] Figure 11 This is a graph showing the changes in micro, meso, and macropore volumes before and after catalyst operation.

[0071] Figure 12 This is a diagram showing the macropore size distribution of carriers with different silicon-to-aluminum ratios.

[0072] Figure 13 XRD patterns of zeolites with different crystallization times.

[0073] Figure 14 The pore structure of zeolites obtained with different alkali treatment times. Detailed Implementation

[0074] Specifically, a long-life bio-oil hydrogenation and upgrading multi-level porous catalyst is prepared by the following steps:

[0075] A. Mix tetraethyl orthosilicate, aluminum source, zeolite seed crystals, alkali, alcohol and water evenly to obtain aluminosilicate gel;

[0076] B. The aluminosilicate gel obtained in step A is subjected to a hydrothermal crystallization reaction. After the hydrothermal reaction is completed, it is washed until neutral to obtain blocky zeolite.

[0077] C. The blocky zeolite obtained in step B is first treated with an alkaline solution, then with an acid solution, and then washed and dried to obtain mesoporous blocky zeolite.

[0078] D. The mesoporous block zeolite obtained in step C is placed in an ammonium salt aqueous solution for ion exchange, and then washed, dried and calcined to obtain a long-life bio-oil hydrogenation and upgrading multi-level porous catalyst support.

[0079] E. The support obtained in step D is impregnated in an aqueous solution of metal salt, and then dried and calcined to obtain a long-life bio-oil hydrogenation and upgrading multi-level porous catalyst.

[0080] In step A, the molar ratio of silicon (SiO2) to aluminum (Al2O3) in the obtained aluminosilicate gel is 30–200.

[0081] This invention utilizes crystal confined crystallization self-assembly technology to construct macroporous channels between crystals and realize the self-assembly of zeolite crystal aggregates. At the same time, a simple alkali / acid leaching technique is used to build intracrystalline mesoporous channels, constructing macroporous channels between intrinsic micropores, intracrystalline mesopores, and nanosheets of zeolite. The hierarchical pore construction mechanism of zeolite-based catalysts is as follows: (1) Macropores: Aluminosilicate gel is a three-dimensional network structure with macroporous channels. Zeolite seeds are dispersed around the aluminosilicate gel skeleton. During hydrothermal crystallization, zeolite crystals grow along the aluminosilicate skeleton with the zeolite seeds as the center to form nano-zeolite sheets, constructing macroporous channels between nanosheet crystals; (2) Mesopores: The zeolite carrier is a crystal composed of aluminosilicate. Alkali solution is used to etch part of the silicon skeleton, and acid solution is used to dissolve the silicon fragments blocked in the crystal, thereby exposing the intracrystalline mesopores etched by alkali solution; (3) Micropores: Intrinsic micropores (<2nm) are formed in the crystal during the hydrothermal crystallization process.

[0082] In step A of this invention, the purpose of uniformly mixing tetraethyl orthosilicate, aluminum source, zeolite seed crystals, alkali, alcohol, and water is to provide the raw materials required for zeolite growth and to form an aluminosilicate gel. The aluminosilicate gel is a three-dimensional network structure with large pore channels, and the zeolite seed crystals dispersed within the aluminosilicate gel framework serve as building blocks for the growth of micron-sized zeolites. This invention requires limiting the type of silicon source. Experiments have shown that tetraethyl orthosilicate is the preferred silicon source for forming the aluminosilicate gel framework; other silicon sources such as fumed silica and inorganic silicates are difficult to use to form the aluminosilicate gel framework.

[0083] In this invention, the aluminum source can be at least one of water-soluble inorganic aluminum salts, organic aluminum salts, or aluminum complexes; preferably, the aluminum source is at least one of sodium aluminate, aluminum sulfate, aluminum nitrate, boehmite, potassium aluminate, and aluminum chloride. In this invention, the alkali can be at least one of water-soluble inorganic sodium or potassium alkalis; preferably, the alkali is at least one of sodium hydroxide, sodium bicarbonate, sodium carbonate, sodium aluminate, potassium hydroxide, potassium bicarbonate, potassium carbonate, and potassium aluminate. In this invention, the zeolite seed crystals can be common zeolite molecular sieves in the art, such as ZSM-5, Beta, HY, and MOR, which are generally in powder form; the alcohol is at least one of methanol, ethanol, n-butanol, and isopropanol.

[0084] Zeolite materials have a crystalline structure, and the silicon-to-aluminum ratio in synthesis affects their crystal phase, thus influencing their porosity. Therefore, this invention requires limiting the molar ratio of SiO2 to Al2O3. Experiments have shown that to form a nanosheet-like crystal structure, the molar ratio of SiO2 to Al2O3 needs to be controlled above 30. If it is below 30, a nanosheet-like crystal structure cannot be formed, making it difficult to use alkali-acid etching to etch the mesopores. In this invention, silicon is derived from tetraethyl orthosilicate. Depending on the specific aluminum source and alkali used, aluminum may originate from an aluminum source, an alkali, or both. Similarly, sodium and potassium may originate from an aluminum source, an alkali, or both. Regardless of the aluminum source and alkali used, it is only necessary to control the molar ratio of silicon (based on SiO2) to aluminum (based on Al2O3), and the molar ratio of sodium and potassium (based on Na2O and K2O) to silicon (based on SiO2) in the aluminosilicate gel according to the parameters of this invention, adjusting the proportions of each raw material accordingly.

[0085] In step A of this invention, the molar ratio of SiO2 to Al2O3, the molar ratio of H2O, Na2O, and / or K2O, and the mass ratio of zeolite seed crystals to SiO2 in the aluminosilicate gel all affect the macroscopic morphology, crystal structure, and pore structure of the final bulk zeolite. Therefore, in order to successfully synthesize zeolite with complete morphology, abundant pores, and zeolite nanosheet-like crystals, and simultaneously achieve intracrystalline etching, the molar ratio of silicon (based on SiO2) to aluminum (based on Al2O3) in the aluminosilicate gel of this invention is 30–200, the molar ratio of sodium and potassium (based on Na2O and K2O) to silicon (based on SiO2) is 0.05–5.0, the molar ratio of H2O to silicon (based on SiO2) is 10–100, the molar ratio of alcohol to silicon (based on SiO2) is 0.5–2.0, and the mass ratio of zeolite seed crystals to silicon (based on SiO2) is 0.01–0.2.

[0086] Furthermore, the stirring time in step A affects the degree of hydrolysis of tetraethyl orthosilicate and the uniformity of the mixture, thereby affecting the construction of the aluminosilicate gel framework and the subsequent crystallization process. The stirring time can be reasonably selected according to the type of zeolite synthesized. To ensure the degree of hydrolysis and uniformity, the mixing method in step A of this invention is as follows: first, dissolve the aluminum source and alkali in water, then add tetraethyl orthosilicate and alcohol dropwise, stir evenly, and finally add zeolite seed crystals and continue stirring for 0.5 to 24 hours.

[0087] Furthermore, in aluminosilicate gels, sodium and potassium participate in the reaction as a whole. In actual production, aluminosilicate gels may contain only sodium, only potassium, or both sodium and potassium, depending on the specific aluminum source and alkali used.

[0088] In step B of this invention, the hydrothermal crystallization reaction time and temperature also affect the crystal structure, pore structure, and compressive stress of the zeolite. Furthermore, the hydrothermal crystallization reaction time and temperature affect the autogenous pressure of water vapor in the reactor, further influencing the macroscopic morphology and compressive stress of the zeolite. Therefore, in step B of this invention, the hydrothermal crystallization temperature is 90–200°C, and the hydrothermal crystallization time is 24–72 hours. The zeolite crystallization process can be completed in 24 hours of hydrothermal reaction; a longer reaction time may reduce the mechanical strength of the catalyst. Therefore, the preferred hydrothermal crystallization time is 24–48 hours.

[0089] In step C of this invention, the purpose of the alkaline solution treatment is to etch silicon elements in the zeolite aluminosilicate framework. The concentration of the alkaline solution, the treatment time, and the temperature determine the degree of framework etching. Therefore, in step C, the concentration of the alkaline solution is controlled at 0.1–0.5 mol / L, and the treatment temperature is 60–80°C. Experiments have shown that the alkaline solution treatment time is 0.5–5.0 h, preferably 1.0–2.0 h. The ratio of the volume of the alkaline solution to the mass of the blocky zeolite obtained in step B is 15–60 mL:1 g. The purpose of the acid treatment is to dissolve silicon fragments blocking the crystals, thereby exposing the mesopores within the crystals. Therefore, in step C, the concentration of the acid solution is controlled at 0.1–0.5 mol / L, the treatment temperature is 60–80°C, and the treatment time is 0.5–6 h. After the alkaline solution treatment, the zeolite is generally filtered, washed, and dried before undergoing acid solution treatment again. The ratio of the volume of the acid solution to the mass of the solid obtained after drying following the alkaline solution treatment is 50–100 mL:1 g. After alkaline solution treatment, the zeolite is generally filtered, washed, and dried before undergoing acid solution treatment. Too high an acid / alkali concentration or too long a treatment time can cause pore collapse and crystal damage, while too low a concentration or too short a treatment time can prevent successful etching of the mesopores within the crystal.

[0090] In step D of this invention, the purpose of ion exchange is to convert sodium-form zeolite into hydrogen-form zeolite. The degree of ion exchange determines the acidity of the catalyst. To ensure the ion exchange effect, in step D, an aqueous solution of ammonium salt (common ammonium salts in the art, such as ammonium chloride, ammonium nitrate, ammonium sulfate, etc.) with a concentration of 0.2–2 mol / L is used. The volume ratio of the ammonium salt aqueous solution to the mass of the block zeolite is controlled at 20–40 mL / g. The ion exchange temperature is controlled at 50–100℃, the ion exchange time at 2–24 h, the drying temperature at 80–105℃, the calcination temperature at 300–500℃, and the calcination time at 2–6 h. Furthermore, the purpose of ion exchange in step D is to use ammonium salt to exchange sodium and / or potassium ions from the zeolite, forming a hydrogen-form structure after calcination. Through experiments, to make the exchange reaction more complete, the ion exchange, drying, and calcination procedures in step D are repeated 2–4 times.

[0091] In step E of this invention, an active metal is loaded onto a zeolite support to obtain a bifunctional blocky zeolite molecular sieve catalyst possessing both metal active sites and acidic sites. In step E, the support is simply submerged in a metal salt aqueous solution. The anions in the metal salt aqueous solution can be common nitrate ions, sulfate ions, etc., and the influence of anions is minimal.

[0092] In step E of this invention, the concentration of the metal salt aqueous solution is 0.01–0.05 g / mL; the metal in the metal salt aqueous solution is at least one selected from V, Cr, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, W, Pt, Au, La, and Ce; and the amount of the metal salt aqueous solution is controlled to maintain a mass ratio of metal to carrier of 0.4–20 wt%.

[0093] In step E of this invention, the impregnation temperature is 50-100°C; the impregnation time is 2-24 hours; the drying temperature is 80-105°C; the calcination temperature is 300-500°C; and the calcination time is 1-5 hours.

[0094] The long-life bio-oil hydrotreating hierarchical porous catalyst support obtained by this invention is in block form, with a diameter of 0.5–5 cm and a thickness of 0.2–3 cm; the specific surface area of ​​the obtained long-life bio-oil hydrotreating hierarchical porous catalyst is 50–200 m². 2 / g, total pore volume is 0.01~0.1cm³ 3 / g.

[0095] Because the long-life bio-oil hydrotreating and upgrading multi-level porous catalyst obtained by this invention has advantages such as excellent macroporous channels, intracrystalline mesopores and regular macroscopic morphology, this invention applies it to the field of bio-oil to gasoline, diesel and aviation fuel technology.

[0096] The present invention will be further described in detail below through embodiments, but the scope of protection of the present invention is not limited to the embodiments described herein.

[0097] Example 1

[0098] Step A: Water was placed in a 100 mL polytetrafluoroethylene hydrothermal reactor liner, followed by the addition of sodium aluminate and sodium hydroxide. The powder was dissolved by magnetic stirring. Then, tetraethyl orthosilicate and ethanol were added dropwise to the above solution, and the mixture was stirred magnetically until homogeneous. Finally, ZSM-5 zeolite seed crystals were added to the above mixture, and the mixture was stirred continuously for 0.5 h to obtain aluminosilicate gel. In the aluminosilicate gel, the molar ratio of silicon (SiO2) to aluminum (Al2O3) was 50, the molar ratio of sodium (Na2O) to silicon (SiO2) was 0.16, the molar ratio of H2O to silicon (SiO2) was 30, the molar ratio of ethanol to silicon (SiO2) was 1.88, and the mass ratio of zeolite seed crystals to silicon (SiO2) was 0.07.

[0099] Step B: The polytetrafluoroethylene (PTFE) liner containing aluminosilicate gel was placed into the reactor, and the reactor was placed in an oven for hydrothermal crystallization. The hydrothermal crystallization temperature was 170℃, and the hydrothermal time was 24 hours. After hydrothermal crystallization, the zeolite was removed and washed with deionized water until neutral to obtain blocky zeolite. Figure 1 ).

[0100] Step C: Take 1.0g of the blocky zeolite obtained in Step B and put it into 30mL of 0.2M sodium hydroxide solution. Keep it in a water bath at 65℃ for 1h. Then filter, wash and dry the zeolite. Take 0.5g of the zeolite and put it into 50mL of 0.1M hydrochloric acid solution. Keep it in a water bath at 65℃ for 5h. Then filter, wash and dry it.

[0101] Step D: 4.0 g of the material obtained in Step C was placed in 80 mL of 1.0 mol / L ammonium chloride aqueous solution for ion exchange, and kept in a water bath at 60 °C for 5 h. After ion exchange, it was washed with deionized water, dried in an oven at 105 °C, and then placed in a quartz boat for calcination in air at 450 °C for 4 h. This step was repeated twice to obtain hydrogen-form massive zeolite (i.e., the support).

[0102] Step E: Hydrogen-form bulk zeolite was placed in a 0.02 g / mL nickel nitrate aqueous solution, with a nickel-to-hydrogen-form bulk zeolite mass ratio of 10%. The solution was kept in a 60°C water bath for 3 hours, followed by drying in a 105°C oven. The resulting mixture was placed in a quartz boat and calcined in air at 450°C for 3 hours to obtain a bifunctional bulk zeolite molecular sieve catalyst.

[0103] The lumpy zeolite obtained in step B was named NaZSM-5.

[0104] After performing step C in Example 1, NaZSM-5 is obtained as NaZSM-5-meso.

[0105] After performing step D in Example 1, the NaZSM-5-meso vector was obtained.

[0106] After performing step E in Example 1, HZSM-5-meso was used to obtain a 10Ni / HZSM-5-meso catalyst.

[0107] NaZSM-5 was not processed in step C and was directly subjected to step D. The resulting catalyst support was named HZSM-5.

[0108] After performing step E in Example 1, HZSM-5 was used to obtain a catalyst named 10Ni / HZSM-5.

[0109] The specific process of bio-oil hydrodeoxygenation is as follows: Weigh 2g of the above-mentioned catalyst and fill it into a fixed-bed reactor. Before the reaction begins, the catalyst is reduced online at 320℃ for 2h, then the bed temperature is lowered to the reaction temperature of 300℃, and the pressure is adjusted to 3MPa. The feedstock (10% guaiacol, with dodecane as the solvent) is pumped into the reactor at a rate of 20mL / h using a liquid feed pump, and the hydrogen flow rate is adjusted to 30mL / min.

[0110] Using 10Ni / HZSM-5-meso as a catalyst, the process was continuously run until the guaiacol conversion rate decreased to 40%. After the operation was completed, the used catalyst was removed and named 10Ni / HZSM-5-meso-used.

[0111] Using 10Ni / HZSM-5 as a catalyst, the process was continuously run until the guaiacol conversion rate decreased to 40%. After the operation was completed, the used catalyst was removed and named 10Ni / HZSM-5-used.

[0112] like Figure 1 As shown, the zeolite obtained in step B is a regular, self-formed, centimeter-sized columnar zeolite.

[0113] The microstructure of the catalyst was characterized by SEM-EDS, and the results are as follows: Figure 2As shown, the catalyst 10Ni / HZSM-5-meso is microscopically a support constructed from zeolite nanosheets. The nanosheet structure shortens the diffusion path of the zeolite, reduces diffusion restriction, and the metal particles are uniformly dispersed and embedded between the nanosheets, exhibiting smaller metal particles, thus achieving high conversion rate, high selectivity, and long lifetime. The catalyst 10Ni / HZSM-5 also exhibits a nanosheet structure, but has larger metal particles. Larger metal particles may be detrimental to the hydrodeoxygenation process.

[0114] The micropore and macropore characteristics of the catalyst were quantitatively determined using nitrogen adsorption-desorption and mercury porosimetry, respectively. Figure 3 It can be seen that the catalyst 10Ni / HZSM-5-meso exhibits typical micro-mesoporous characteristics and well-developed macroporous characteristics, with the macropore size distributed at around 7252nm; while the mesopores and macropores (7192nm) of the catalyst 10Ni / HZSM-5 are smaller than those of 10Ni / HZSM-5-meso.

[0115] Nitrogen adsorption-desorption was used to characterize the micropore size distribution of the catalyst. Figure 4 It can be seen that the catalyst 10Ni / HZSM-5-meso has a similar micropore distribution to 10Ni / HZSM-5, but it has a wider mesopore size.

[0116] The adsorption rate of the catalyst for the product molecule cyclohexane was evaluated using an intelligent gravimetric adsorption analyzer. Figure 5 It can be seen that the adsorption rate of cyclohexane by the catalyst 10Ni / HZSM-5-meso is much faster than that of 10Ni / HZSM-5. This is because 10Ni / HZSM-5-meso has more developed meso-macropore characteristics and zeolite nanosheet structure, which promotes the mass transfer and diffusion of product molecules between catalyst pores.

[0117] Catalyst lifetime was evaluated using a continuous flow fixed-bed reactor, and guaiacol conversion was quantitatively analyzed by GC, with 40% conversion considered the lowest point. Figure 6 It is known that when the conversion rate of guaiacol decreases to 40%, the catalyst 10Ni / HZSM-5-meso can operate for 63 hours, while the operating time of 10Ni / HZSM-5 is only 11 hours, with the former having a lifespan 5 to 6 times longer than the latter. This is because the well-developed mesoporous and zeolite nanosheet structure enhances the overall mass transfer rate of the catalyst. Oxygen-containing guaiacol is rapidly transferred to the surface of the zeolite nanosheet crystals through the macroporous channels between the zeolite nanosheets. Due to the nanosheet characteristics of the catalyst, the reaction molecules in the macropores are transferred to the mesopores within the crystals more quickly. Guaiacol undergoes further bond breaking and deoxygenation in the mesopores, and then the intermediate products are transported to the microporous active centers, achieving efficient and directional conversion of guaiacol, thereby extending the reaction lifespan.

[0118] The conversion products were quantitatively and qualitatively analyzed using GC and GC-MS, respectively, and the selectivity of the main product cyclohexane was calculated. Figure 7 It can be seen that the selectivity of the catalyst 10Ni / HZSM-5-meso is stable at around 75%, while the selectivity of 10Ni / HZSM-5 is about 67%. This indicates that the macroporous and zeolite nanosheet characteristics can improve the selectivity of the catalyst, thereby improving the quality of the oil.

[0119] The crystal structure of the catalyst was characterized using XRD. Figure 8 It can be seen that both catalysts 10Ni / HZSM-5-meso and 10Ni / HZSM-5 exhibit the complete crystal structure of ZSM-5 and no impurity peaks were observed, indicating that the catalyst zeolite support preparation method is feasible, the alkaline and acid treatment did not destroy its crystal structure, and the active metal is uniformly distributed on the support surface; moreover, the crystal structure of both types of catalysts remains intact after use, indicating that the catalysts have stability under high temperature and high pressure.

[0120] The carbon deposition distribution of the catalyst after use was evaluated using TG-DTG, and the results are as follows: Figure 9 .Depend on Figure 9 It can be seen that the carbon deposition of the catalyst prepared by 10Ni / HZSM-5-meso-used is only 1.0 wt.%, which is lower than that of 10Ni / HZSM-5-used (1.3 wt.%). This is also because the synergistic effect of the former's mesoporous characteristics and zeolite nanosheet structure leads to the catalyst having rapid mass transfer and lower carbon deposition content.

[0121] like Figure 3 , Figure 4 The pore structure of the catalyst after use can be determined. (From...) Figure 3 It can be seen that after using catalysts 10Ni / HZSM-5-meso and 10Ni / HZSM-5, the micropores and mesopores were almost completely covered, while the macropores remained intact. Figure 4 It can be seen that the micro-mesopores of the catalyst 10Ni / HZSM-5-meso-used are superior to those of 10Ni / HZSM-5-used. This is because the former has a higher degree of micro-mesopore retention due to the mass transfer channels of the micro-meso-macropore gradation, which means that the active centers are not completely covered, and therefore the former has a longer lifespan.

[0122] Figure 10The microstructure and surface elemental distribution of the catalyst after use are shown. SEM-EDS results show that the carbon content on the 10Ni / HZSM-5-meso-used surface is 10.0%, lower than that of 10Ni / HZSM-5-used (10.8%) and TG-DTG results, indicating that a large amount of carbon is distributed on the catalyst surface, and the hierarchical porous catalyst has better anti-carbon deposition performance than the micro-macroporous catalyst. In addition, the Ni content on the surface of 10Ni / HZSM-5-meso-used after use is much lower than that of 10Ni / HZSM-5-used, indicating that the metal in 10Ni / HZSM-5-meso is uniformly distributed between zeolite nanosheets rather than on the catalyst surface, shortening the distance between metal sites and microporous active centers, which is more conducive to improving catalyst conversion efficiency and lifetime.

[0123] Table 1 Pore structure of support and catalyst

[0124]

[0125] Note: S BET S mic S ext V tot V mic V meso D p All results are from nitrogen adsorption-desorption tests, V macro and D macro All results are from mercury porosimetry tests.

[0126] To reveal the mechanism by which hierarchical pore structure affects the hydrodeoxygenation lifetime, Example 1 presents the porosity changes before and after catalyst use. See Table 1 and... Figure 11 As shown, after alkali and acid treatment, the mesopore and macropore volumes of 10Ni / HZSM-5-meso are 0.028 cm³ and 0.028 cm³, respectively. 3 / g and 0.840cm 3 / g (Table 1), all higher than 10Ni / HZSM-5 ( Figure 11 Therefore, acid-base treatment increases the intergranular macropore and intragranular mesopore volume of the zeolite-based catalyst. Since the macropore diameter of 10Ni / HZSM-5-meso is as high as 734.7 nm, much larger than that of zeolite crystals, it is defined as intergranular macropores. Alkali-acid treatment only targets zeolite crystals, etching the crystal to form mesopores, which are therefore defined as intragranular mesopores. The increased mesopore-macropore volume of 10Ni / HZSM-5-meso promotes catalytic efficiency, improving catalyst lifetime and selectivity.

[0127] As shown in Table 1 and Figure 11As shown, 10Ni / HZSM-5-meso-used exhibits a higher micropore size (0.023 cm) after 63 hours of use compared to 10Ni / HZSM-5-used after 11 hours of use. 3 / g) and mesopore volume (0.022cm³) 3 / g), indicating that the introduction of mesopores protects the microporous active centers and mesoporous transition sections. However, the macropore volume of 10Ni / HZSM-5-meso-used (0.516 cm³ / g) is still relatively small. 3 / g) less than 10Ni / HZSM-5-used (0.840cm 3 This may be because the meso-macropores of 10Ni / HZSM-5-used are underdeveloped, thus deactivating after 11 hours. The macropores did not transfer much reactant to the micro-mesopores, resulting in minimal change in macropore volume. However, the meso-macropores of 10Ni / HZSM-5-meso-used are well-developed, with a reaction time as long as 63 hours, fully utilizing the high-speed mass transfer function of the macropores, leading to blockage of the macropore mass transfer channels and a decrease in macropore volume.

[0128] Therefore, the above results demonstrate that the meso-macroporous effect of 10Ni / HZSM-5-meso significantly prolongs the catalyst lifetime.

[0129] Example 2

[0130] Example 2 uses HZSM-5 zeolite with a silica-to-alumina ratio of 10 as raw material to investigate the mesoporous structure of low silica-to-alumina ratio zeolite after alkali-acid treatment. Figure 12 As shown in Table 2, the specific surface area and pore volume of the carrier after alkaline treatment were lower than those of HZSM-5 (Si / Al = 10), because the silicon residue dissolved by the alkali blocked the pores. After acid treatment, the silicon residue blocking the pores was dissolved, and the specific surface area and pore volume increased compared to HZSM-5 (Si / Al = 10). However, under low silicon-to-aluminum ratio conditions, it is difficult to etch mesopores, and their V... meso Only 0.006cm 3 / g, which is much lower than that of HZSM-5 (Si / Al=10).

[0131] Table 2 Pore structure of the carrier

[0132]

[0133] Therefore, the silicon-to-aluminum ratio needs to be limited to greater than 30 in order to form nanosheet zeolite, which in turn allows for the formation of intracrystalline mesopores through alkaline-acid etching.

[0134] Example 3

[0135] The crystal dynamics and evolution process of zeolites were investigated, and the crystal formation of zeolites under different hydrothermal time conditions was studied. For example... Figure 13As shown, the hydrothermal time was 3 hours, during which the zeolite exhibited an amorphous morphology, composed of aluminosilicates. Characteristic peaks of ZSM-5 were gradually observed from 6 to 12 hours, indicating that the aluminosilicate framework gradually transformed into zeolite with increasing hydrothermal time. A complete ZSM-5 zeolite crystal form was formed after 24 hours. Example 4 demonstrates that the zeolite synthesis time was only 24 hours, shorter than that of traditional zeolites. This is because the specific proportions and types of raw materials formed a cross-linked aluminosilicate framework, resulting in a tight bond between the zeolite precursor and the zeolite seed crystals, leading to a shorter overall crystallization time and reduced production energy consumption. The nanosheet structure of the catalyst of this invention can be rapidly synthesized without templates, structure-directing agents, or post-processing steps, offering advantages such as low cost, environmental friendliness, and ease of scaling up.

[0136] Example 4

[0137] Example 4 used NaZSM-5 with a silicon-to-aluminum ratio of 50 as raw material to investigate the effect mechanism of different alkali treatment times on alkali-acid treatment. Figure 14 As shown, the porosity was significantly improved compared to NaZSM-5 when the alkali treatment time was 0.5 h. The pore structure was most developed when the alkali treatment time was 1.0 h. Extending the alkali treatment time to 5.0 h resulted in a slight decrease in porosity. Therefore, the preferred alkali treatment time is 1.0–2.0 h.

Claims

1. A long life bio-oil hydro-upgrading multi-level pore catalyst characterized by: The preparation method comprises the following steps: A. uniformly mixing tetraethyl orthosilicate, an aluminum source, zeolite seeds, an alkali, an alcohol and water to obtain a silico-aluminate gel; B. performing a hydrothermal crystallization reaction on the silico-aluminate gel obtained in step A, and washing to neutral after the hydrothermal reaction to obtain a blocky zeolite; C. treating the blocky zeolite obtained in step B with an alkali solution, then with an acid solution, and then washing and drying to obtain a mesoporous blocky zeolite; D. placing the mesoporous blocky zeolite obtained in step C in an aqueous ammonium salt solution to perform ion exchange, and then washing, drying and calcining to obtain a long-life bio-oil hydro-upgrading multi-level pore catalyst carrier; E. placing the carrier obtained in step D in an aqueous metal salt solution to perform impregnation, and then drying and calcining to obtain a long-life bio-oil hydro-upgrading multi-level pore catalyst; In step A, the molar ratio of silicon calculated as SiO2 to aluminum calculated as Al2O3 in the obtained silico-aluminate gel is 30-200; In step C, the alkali in the alkali solution is at least one of sodium hydroxide and potassium hydroxide; In step C, the concentration of the alkali solution is 0.1-0.5 mol / L; In step C, the ratio of the volume of the alkali solution to the mass of the blocky zeolite obtained in step B is 15-60 mL:1 g; In step C, the temperature of the alkali solution treatment is 60-80℃; In step C, the time of the alkali solution treatment is 1.0-2.0 h.

2. The long life bio-oil hydro-upgrading multi-level pore catalyst according to claim 1, characterized in that: In step A, the aluminum source is at least one of a water-soluble inorganic aluminum salt, an organic aluminum salt or an aluminum complex.

3. The long life bio-oil hydro-upgrading multi-level pore catalyst of claim 2, wherein: In step A, the aluminum source is at least one of sodium meta-aluminate, aluminum sulfate, aluminum nitrate, pseudo-boehmite, potassium meta-aluminate and aluminum chloride.

4. The long life bio-oil hydro-upgrading multi-level pore catalyst of claim 1, wherein: In step A, the zeolite seeds are at least one of ZSM-5, Beta, MOR, Y-type and X-type.

5. The long life bio-oil hydro-upgrading multi-level pore catalyst of claim 1, wherein: In step A, the alkali is at least one of an inorganic water-soluble sodium base or potassium base.

6. The long life bio-oil hydro-upgrading multi-level pore catalyst of claim 5, wherein: In step A, the alkali is at least one of sodium hydroxide, sodium bicarbonate, sodium carbonate, sodium meta-aluminate, potassium hydroxide, potassium bicarbonate, potassium carbonate and potassium meta-aluminate.

7. The long-life bio-oil hydro-upgrading multi-level pore catalyst of claim 1, wherein: In step A, the alcohol is at least one of methanol, ethanol, n-butanol and isopropyl alcohol.

8. The long life bio-oil hydro-upgrading multi-level pore catalyst of claim 1, wherein: In step A, in the obtained silico-aluminate gel, the molar ratio of sodium and potassium calculated as Na2O and K2O to silicon calculated as SiO2 is 0.05-5.0, the molar ratio of H2O to silicon calculated as SiO2 is 10-100, the molar ratio of alcohol to silicon calculated as SiO2 is 0.5-2.0, and the mass ratio of zeolite seeds to silicon calculated as SiO2 is 0.01-0.

2.

9. The long lifetime bio-oil hydro-upgrading multi-level pore catalyst of claim 1, wherein: In step A, the uniform mixing manner is: first dissolving the aluminum source and the alkali in water, then adding tetraethyl orthosilicate and the alcohol dropwise, stirring uniformly, and finally adding the zeolite seeds, and continuously stirring for 0.5-24 h.

10. The long lifetime bio-oil hydro-upgrading multi-level pore catalyst of claim 1, wherein: In step B, the temperature of the hydrothermal crystallization reaction is 90-200℃.

11. The long life bio-oil hydro-upgrading multi-level pore catalyst of claim 10, wherein: In step B, the temperature of the hydrothermal crystallization reaction is 170-200℃.

12. The long-life bio-oil hydro-upgrading multi-level pore catalyst of claim 1, wherein: In step B, the time of the hydrothermal crystallization reaction is 24-72 h.

13. The long lifetime bio-oil hydro-upgrading multi-level pore catalyst of claim 12, wherein: In step B, the time of the hydrothermal crystallization reaction is 24-48 h.

14. The long lifetime bio-oil hydro-upgrading multi-level pore catalyst of claim 1, wherein: In step C, at least one of the following is met: the acid solution is at least one of hydrochloric acid and hydrofluoric acid; The concentration of the acid solution is 0.1-0.5 mol / L; The ratio of the volume of the acid solution to the mass of the solid after treatment with the alkali solution is 50-100 mL:1 g; The temperature of the acid solution treatment is 60-80℃; The acid solution treatment time is 0.5-6 h.

15. The long-life bio-oil hydro-upgrading multi-level pore catalyst of claim 1, wherein: In step D, at least one of the following is satisfied: The ammonium salt is at least one of ammonium chloride, ammonium nitrate, and ammonium sulfate; The concentration of the aqueous ammonium salt solution is 0.2-2 mol / L; The ratio of the volume of the aqueous ammonium salt solution to the mass of the block-shaped zeolite is 20-40 mL / g; The ion exchange temperature is 50-100℃; The ion exchange time is 2-24 h; The drying temperature is 80-105℃; The calcination temperature is 300-500℃; The calcination time is 2-6 h; The step D operation needs to be repeated 2-4 times.

16. The long-life bio-oil hydro-upgrading multi-level pore catalyst of claim 1, wherein: In step E, at least one of the following is satisfied: The concentration of the aqueous metal salt solution is 0.01-0.05 g / mL; The metal in the aqueous metal salt solution is at least one of V, Cr, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, W, Pt, Au, La, and Ce; The amount of the aqueous metal salt solution is controlled so that the mass ratio of the metal in the aqueous metal salt solution to the carrier is 0.4-20 wt%; The impregnation temperature is 50-100℃; The impregnation time is 2-24 h; The drying temperature is 80-105℃; The calcination temperature is 300-500℃; The calcination time is 1-5 h.

17. The long-life bio-oil hydro-upgrading multi-level pore catalyst of any of claims 1-16, wherein: The long-life bio-oil hydro-upgrading multi-level pore catalyst carrier obtained in step D is block-shaped, with a diameter of 0.5-5 cm and a thickness of 0.2-3 cm.

18. The long-life bio-oil hydro-upgrading multi-level pore catalyst of any of claims 1-16, wherein: The specific surface area of the long-life bio-oil hydro-upgrading multi-stage pore catalyst obtained in step E is 50-200 m 2 / g, and the total pore volume is 0.01-0.1 cm 3 / g.

19. Use of the long-life bio-oil hydro-upgrading multi-level pore catalyst of any one of claims 1-18 in the production of gasoline, diesel, and / or jet fuel from bio-oil.

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