Heteropolyacid modified metal-based solid acid catalyst, application thereof and method for catalytically pyrolyzing fossil energy, biomass or solid waste

Abstract

The invention relates to the fields of catalytic materials, energy technologies and the like, and discloses a heteropolyacid modified metal-based solid acid catalyst, application thereof and a method for catalytically pyrolyzing fossil energy, biomass or solid waste. The heteropolyacid modified metal-based solid acid catalyst comprises heteropolyacid and boehmite, is used for pyrolyzing fossil energy, biomass or solid waste, greatly reduces the activation energy of pyrolytic reaction, improves the selectivity of pyrolysis products, improves the value of the pyrolysis products, and has guiding significance for conversion and utilization of the fossil energy, biomass or solid waste.

Description

Technical Field

[0001] This invention relates to the fields of catalytic materials and energy technology, specifically to a heteropolyacid modified metal-based solid acid catalyst and its application, as well as a method for catalytic pyrolysis of fossil energy, biomass, or solid waste. Background Technology

[0003] Fossil energy includes conventional and unconventional fossil energy. Conventional fossil energy includes coal, oil, and natural gas. Currently, global conventional energy reserves are being depleted at a tremendous pace, with proven reserves declining year by year. Therefore, developing unconventional fossil energy, which has vast reserves distributed across the globe, is crucial. Representative unconventional fossil energy sources include oil shale, shale oil, and oil sands. Utilizing these helps increase the diversity of energy supply and, to some extent, reduces dependence on traditional fossil energy. Among these, oil shale research is currently a hot topic of widespread attention and in-depth exploration by researchers in various fields. Oil shale is a combustible sedimentary rock rich in organic matter and high in ash. The organic matter is mainly kerogen, a precursor to oil and natural gas. Through a series of thermal and pressure processes, it can be converted into combustible hydrocarbon compounds. Oil shale reserves are abundant, far exceeding those of coal and crude oil. Therefore, oil shale is of great significance in terms of energy supply, economic development, and energy security.

[0004] Oil shale can be processed and utilized through pyrolysis, gasification, extraction, and combustion. Among these methods, pyrolysis to produce shale oil is one of the most efficient means of its development and utilization. Pyrolysis refers to the process of heating oil shale to a certain temperature and decomposing it under an oxygen-free or inert atmosphere. It consists of two steps: dry distillation and cracking. Through pyrolysis, the organic matter in oil shale can be decomposed into bitumen and other substances. Then, the bitumen cracks into shale oil, shale gas, and residual carbon through a series of complex endothermic or exothermic reactions. However, the pyrolysis process of oil shale has high energy consumption, low product quality, and relatively high process costs. To date, scholars at home and abroad have conducted extensive research on the factors affecting oil shale pyrolysis. Among these, catalytic pyrolysis can improve the conversion rate and quality of pyrolysis products while reducing reaction energy consumption and process costs. Therefore, utilizing catalysts for catalytic pyrolysis of oil shale has become one of the important research topics at present.

[0005] Researching the catalytic pyrolysis of oil shale and finding a low-cost, readily available, and highly efficient catalyst is crucial for improving the selectivity of pyrolysis products, reducing waste generation, and lowering production costs. Currently, natural and synthetic catalysts are the two most commonly used types of catalysts in oil shale pyrolysis, each with its own advantages and disadvantages, but both also have limitations. Therefore, researchers are actively exploring more efficient, economical, and environmentally friendly catalyst materials to achieve better results in oil shale pyrolysis and contribute to the sustainable development of energy and resources. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems of high energy consumption and poor selectivity of catalysts used in the pyrolysis of fossil fuels, biomass, or solid waste in existing technologies, and to provide a heteropolyacid-modified metal-based solid acid catalyst, its application, and a method for catalytic pyrolysis of fossil fuels, biomass, or solid waste. The heteropolyacid-modified metal-based solid acid catalyst of this invention comprises heteropolyacids and boehmite. Using this catalyst for the pyrolysis of fossil fuels, biomass, or solid waste significantly reduces the activation energy of the pyrolysis reaction, improves the selectivity of the pyrolysis products, and increases the value of the pyrolysis products.

[0007] To achieve the above objectives, the first aspect of the present invention provides a heteropolyacid-modified metal-based solid acid catalyst, wherein the heteropolyacid-modified metal-based solid acid catalyst comprises heteropolyacid and boehmite.

[0008] Preferably, in the heteropolyacid modified metal-based solid acid catalyst, the total Brønsted acid concentration is 0.01-10000 μmol / g, and the total Lewis acid concentration is 0.01-10000 μmol / g.

[0009] Preferably, in the heteropolyacid modified metal-based solid acid catalyst, the concentration of medium-strength Brønsted acid is 0.01-10000 μmol / g, and the concentration of medium-strength Lewis acid is 0.01-10000 μmol / g.

[0010] The second aspect of this invention provides the application of the heteropolyacid modified metal-based solid acid catalyst described in the first aspect above in the processing and treatment of fossil energy, biomass or solid waste.

[0011] A third aspect of the present invention provides a method for catalytic pyrolysis of fossil energy, biomass, or solid waste, the method comprising: contacting the heteropolyacid-modified metal-based solid acid catalyst described in the first aspect with fossil energy, biomass, or solid waste and carrying out a pyrolysis reaction under an inert gas, oxygen-deficient, or non-oxidizing gas atmosphere to obtain pyrolysis products.

[0012] The beneficial technical effects achieved by the present invention through the above technical solution are as follows:

[0013] (1) The heteropolyacid-modified metal-based solid acid catalyst provided by the present invention comprises heteropolyacid and boehmite. The introduction of the heteropolyacid-modified metal-based solid acid catalyst greatly reduces the activation energy of the pyrolysis reaction, and the selectivity of the heteropolyacid-modified metal-based solid acid catalyst further increases the hydrocarbon content in the pyrolysis products, reduces the heteroatom content, and increases the content of high-quality petroleum-like fuels and high-value-added chemicals, which has significant industrial and economic potential and has certain guiding significance for the conversion and utilization of fossil energy, biomass or solid waste.

[0014] (2) In this invention, the heteropolyacid modified metal-based solid acid catalyst is used for the catalytic pyrolysis of oil shale. Compared with the non-catalytic system of oil shale, the activation energy of the pyrolysis reaction of oil shale is reduced by 11.2% after the introduction of the catalyst, which significantly reduces the activation energy, reduces the heteroatom content, and increases the hydrocarbon content. In particular, the content of high-value-added pyrroles, thiophenes, α-olefins, dienes and monocyclic aromatics is significantly increased. Attached Figure Description

[0015] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof.

[0016] Figure 1 A is a scanning electron microscope image of the heteropolyacid-modified metal-based solid acid catalyst provided by the present invention; Figure 1 B is a transmission electron microscope image of the heteropolyacid-modified metal-based solid acid catalyst provided by the present invention; Figure 1 C to 1F are the energy color scattering line spectra of the heteropolyacid modified metal-based solid acid catalyst provided by the present invention;

[0017] Figure 2 A is the XRD pattern of the heteropolyacid-modified metal-based solid acid catalyst provided by this invention; Figure 2 B is the FTIR spectrum of the heteropolyacid-modified metal-based solid acid catalyst provided by this invention;

[0018] Figure 3 This is the Py-FTIR image of the heteropolyacid-modified metal-based solid acid catalyst provided by this invention;

[0019] Figure 4 A and Figure 4 B represents the TG and DTG curves of the oil shale pyrolysis system with heteropolyacid-modified metal-based solid acid catalyst and the original oil shale pyrolysis system without heteropolyacid-modified metal-based solid acid catalyst at a heating rate of 20 K / min, respectively. Figure 4 C and Figure 4D represents the TG and DTG curves of the oil shale pyrolysis system with heteropolyacid-modified metal-based solid acid catalyst and the original oil shale pyrolysis system without heteropolyacid-modified metal-based solid acid catalyst at different heating rates.

[0020] Figure 5 A is a linear regression diagram of the oil shale pyrolysis system with a heteropolyacid-modified metal-based solid acid catalyst, fitted based on the FWO approximation equation. Figure 5 B is a linear regression diagram of the oil shale pyrolysis system without heteropolyacid modified metal-based solid acid catalysts, fitted based on the FWO approximation equation; Figure 5 C is a distribution diagram of Eα as a function of α in different oil shale pyrolysis systems obtained based on the FWO method;

[0021] Figure 6 A is the Py-EGA-MS plot of different oil shale pyrolysis systems; Figure 6 B is the MS diagram of the products generated in the first peak region of different oil shale pyrolysis systems; Figure 6 C is the MS diagram of the products generated in the second peak region of different oil shale pyrolysis systems;

[0022] Figure 7 A and 7B are the total ion current chromatograms (TIC) of the reaction products before and after the catalytic pyrolysis of oil shale at low temperature (453℃) and high temperature (600℃), respectively.

[0023] Figure 8 A- Figure 8 G. Schematic diagram of the distribution of each component in the products obtained from the pyrolysis reaction of different oil shale pyrolysis systems at low temperature (453℃);

[0024] Figure 9 A- Figure 9 G. Schematic diagram of the distribution of each component in the products obtained from the pyrolysis reaction of different oil shale pyrolysis systems at high temperature (600℃). Detailed Implementation

[0025] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0026] The first aspect of the present invention provides a heteropolyacid-modified metal-based solid acid catalyst, wherein the heteropolyacid-modified metal-based solid acid catalyst comprises heteropolyacid and boehmite.

[0027] In this invention, a heteropolyacid-modified metal-based solid acid catalyst comprising heteropolyacids and boehmite is selected. In the pyrolysis reaction of fossil fuels, the L (Lewis) acid and / or B (Boehmite) of the catalyst... Acids can serve as catalytic active sites. Combined with Py-FTIR results, the heteropolyacid-modified metal-based solid acid catalyst possesses excellent Brønsted (B) and Lewis (L) acid sites, with the intensity and concentration of B sites significantly higher than those of Lewis sites. The synergistic and competitive effects of these two acid sites guide the thermochemical conversion reaction preferentially along specific pathways, endowing the heteropolyacid-modified metal-based solid acid catalyst with excellent catalytic performance. Furthermore, the heteropolyacid provides numerous acidic centers with high catalytic activity, and boehmite has a porous structure with abundant Lewis acid sites; the synergistic effect of these two factors further enhances the catalytic performance of the heteropolyacid-modified metal-based solid acid catalyst.

[0028] In this invention, unless otherwise specified, the heteropolyacid refers to a class of oxypolyacids composed of heteroatoms and polyatoms connected by oxygen atom coordination bridging in a certain structure.

[0029] In some embodiments of the present invention, preferably, the total Brønsted acid concentration in the heteropolyacid-modified metal-based solid acid catalyst is 0.01-10000 μmol / g; the total Lewis acid concentration is 0.01-10000 μmol / g. In the present invention, the total Brønsted acid concentration in the heteropolyacid-modified metal-based solid acid catalyst can be any value within the range of 0.01 μmol / g, 1 μmol / g, 10 μmol / g, 20 μmol / g, 30 μmol / g, 40 μmol / g, 50 μmol / g, 60 μmol / g, 70 μmol / g, 80 μmol / g, 100 μmol / g, 300 μmol / g, 500 μmol / g, 1000 μmol / g, 4000 μmol / g, 7000 μmol / g, 10000 μmol / g, or any combination of two such values, preferably 1-1000 μmol / g, more preferably 5-100 μmol / g. / g; the total L acid concentration in the heteropolyacid-modified metal-based solid acid catalyst can be 0.01 μmol / g, 1 μmol / g, 10 μmol / g, 20 μmol / g, 30 μmol / g, 40 μmol / g, 50 μmol / g, 60 μmol / g, 70 μmol / g, 80 μmol / g, 100 μmol / g, 300 μmol / g, 500 μmol / g, 1000 μmol / g, 4000 μmol / g, 7000 μmol / g, 10000 μmol / g, or any value within any range of two such values, preferably 1-1000 μmol / g, more preferably 5-100 μmol / g. In this invention, unless otherwise specified, the total Brønsted acid concentration refers to the Brønsted acid concentration at 200°C, and the total L acid concentration refers to the L acid concentration at 200°C.

[0030] In some embodiments of the present invention, preferably, the concentration of the medium-strength Brønsted acid in the heteropolyacid-modified metal-based solid acid catalyst is 0.01-10000 μmol / g; and the concentration of the medium-strength Lewis acid is 0.01-10000 μmol / g. In this invention, the concentration of the moderately strong Brønsted acid in the heteropolyacid-modified metal-based solid acid catalyst can be 0.01 μmol / g, 1 μmol / g, 10 μmol / g, 20 μmol / g, 30 μmol / g, 40 μmol / g, 50 μmol / g, 60 μmol / g, 70 μmol / g, 80 μmol / g, 100 μmol / g, 300 μmol / g, 500 μmol / g, 1000 μmol / g, 4000 μmol / g, 7000 μmol / g, 10000 μmol / g, or any value within any range of two such values, preferably 1-1000 μmol / g, more preferably 5-100 μmol / g; In this invention, the concentration of the moderately strong Brønsted acid (B acid) in the heteropolyacid-modified metal-based solid acid catalyst can be any value within the range of 0.01 μmol / g, 1 μmol / g, 10 μmol / g, 20 μmol / g, 30 μmol / g, 40 μmol / g, 50 μmol / g, 60 μmol / g, 70 μmol / g, 80 μmol / g, 100 μmol / g, 300 μmol / g, 500 μmol / g, 1000 μmol / g, 4000 μmol / g, 7000 μmol / g, 10000 μmol / g, or any combination of two such values, preferably 1-1000 μmol / g, more preferably 5-100 μmol / g. Unless otherwise specified, the moderately strong Brønsted acid concentration refers to the Brønsted acid concentration at 350°C, and the moderately strong Lewis acid concentration refers to the Lewis acid concentration at 350°C.

[0031] In this invention, the mass ratio of the heteropolyacid to boehmite has a wide range of selection, as long as both are present simultaneously and the concentrations of the Brønsted acid and Lewis acid meet the aforementioned range. Preferably, the mass ratio of the heteropolyacid to boehmite is 1:0.5-18, for example, it can be 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, or any value within the range of any two values, preferably 1:1-10, more preferably 1:4-7.

[0032] In this invention, controlling the mass ratio of phosphotungstic acid and boehmite within the above-mentioned range is beneficial to ensuring that the obtained heteropolyacid-modified metal-based solid acid catalyst has good catalytic activity, which helps to reduce the activation energy of the pyrolysis reaction, improve the selectivity of the pyrolysis products, and increase the value of the pyrolysis products.

[0033] In this invention, the heteropolyacid can provide more acidic centers, has high catalytic activity, rapidly activates reactant molecules, reduces the activation energy of the pyrolysis reaction, thereby accelerating the pyrolysis reaction rate and reducing reaction energy consumption.

[0034] In some embodiments of the present invention, preferably, the heteropolyacid comprises heteroatoms and polyatoms; the heteroatoms are selected from at least one of Group IIIA, Group IVA, Group VA and Group VIII of the third period, preferably from at least one of P, Si, Fe and Co, and more preferably from P and / or Si.

[0035] In some embodiments of the present invention, preferably, the polyatomic element is selected from Group VB metal elements and / or Group VIIB metal elements, more preferably selected from at least one of Mo, W, V, Nb and Ta, and more preferably W.

[0036] In some embodiments of the present invention, preferably, the heteropolyacid has a keggin structure.

[0037] In this invention, the keggin-type heteropolyacid exhibits high catalytic activity, and its unique structure and catalytic properties are more conducive to selectively promoting the content of hydrocarbon compounds in the pyrolysis products. ， Reducing the content of heteroatom compounds helps improve the quality and value of pyrolysis products.

[0038] In this invention, the type of heteropolyacid can be selected from a wide range. Preferably, the heteropolyacid is phosphotungstic acid.

[0039] In this invention, the phosphotungstic acid exhibits superior catalytic performance in the catalytic pyrolysis of fossil fuels, biomass, or solid waste. This is beneficial for further increasing the hydrocarbon content in the pyrolysis products, reducing the heteroatom content, promoting the lightweighting of the pyrolysis products, and increasing the content of high-value-added chemicals and high-quality petroleum-like fuels.

[0040] In some embodiments of the present invention, preferably, the catalyst has the chemical formula (H3PW). 12 O 40 ) m / (γ-AlOOH) n Where n≠0 and m≠0. In this invention, the mass ratio of the heteropolyacid to boehmite is equivalent to the m:n ratio in the chemical formula of the catalyst.

[0041] In this invention, the preparation method of the heteropolyacid modified metal-based solid acid catalyst is not particularly limited. For example, heteropolyacid and boehmite can be mixed.

[0042] In this invention, the mixing method is not particularly limited, as long as the heteropolyacid and boehmite are mixed evenly. For example, impregnation, deposition precipitation, ion exchange, etc., can be used for mixing, with impregnation being preferred. In this invention, the conditions for the impregnation method are not particularly limited. The heteropolyacid-modified metal-based solid acid catalyst prepared by impregnation is dried and then ground into powder. The term "powder" in this invention refers to a powdery form without obvious particles or with particularly fine particles.

[0043] The second aspect of this invention provides the application of the heteropolyacid modified metal-based solid acid catalyst described in the first aspect above in the processing and treatment of fossil energy, biomass or solid waste.

[0044] In some embodiments of the present invention, preferably, the fossil energy source is selected from at least one of coal, petroleum, heavy oil, oil shale, shale oil and oil sands, and preferably oil shale.

[0045] In some embodiments of the present invention, preferably, the biomass is selected from at least one of wood, forest waste, aquatic plants, oil plants and animal manure.

[0046] In some embodiments of the present invention, preferably, the solid waste is selected from at least one of plastics, waste oil, agricultural waste, waste food, and waste garbage.

[0047] In this invention, the range of processing and treatment methods is relatively wide. Preferably, the processing and treatment method is catalytic pyrolysis.

[0048] In this invention, the heteropolyacid-modified metal-based solid acid catalyst comprises heteropolyacid and boehmite. Using this heteropolyacid-modified metal-based solid acid catalyst to process and treat fossil fuels (especially oil shale), biomass, or solid waste significantly reduces the activation energy of the pyrolysis reaction. Through the selective alteration of the reaction pathway by this catalyst, the hydrocarbon content in the pyrolysis products is increased, the heteroatom content is reduced, and the pyrolysis products are made lighter, increasing the content of high-value-added chemicals and high-quality petroleum-like fuels, demonstrating significant industrial and economic potential.

[0049] In this invention, unless otherwise specified, the activation energy parameter of the pyrolysis reaction is obtained from the relationship curve between the weight loss rate and temperature of fossil energy, biomass or solid waste.

[0050] In this invention, unless otherwise specified, the activation energy change rate parameter is obtained by analyzing the relationship curves between weight loss rate and temperature of the pyrolysis system containing heteropolyacid-modified metal-based solid acid catalyst and the pyrolysis system without heteropolyacid-modified metal-based solid acid catalyst. The activation energy of each system is obtained by comparing and analyzing the activation energies of the pyrolysis system containing heteropolyacid-modified metal-based solid acid catalyst and the pyrolysis system without heteropolyacid-modified metal-based solid acid catalyst.

[0051] A third aspect of the present invention provides a method for catalytic pyrolysis of fossil energy, biomass, or solid waste, the method comprising: contacting the heteropolyacid-modified metal-based solid acid catalyst described in the first aspect with fossil energy, biomass, or solid waste and carrying out a pyrolysis reaction under an inert gas, oxygen-deficient, or non-oxidizing gas atmosphere to obtain pyrolysis products.

[0052] In this invention, the use of the heteropolyacid-modified metal-based solid acid catalyst described herein for the catalytic pyrolysis of fossil fuels, biomass, or solid waste is beneficial for reducing the activation energy of the pyrolysis reaction. By selectively altering the reaction pathway through the catalyst, the hydrocarbon content in the pyrolysis products is increased, the heteroatom content is reduced, and the pyrolysis products are made lighter, thereby increasing the content of high-value-added chemicals and high-quality petroleum-like fuels, which has significant industrial and economic potential.

[0053] In some embodiments of the present invention, preferably, the fossil energy source is selected from at least one of coal, petroleum, heavy oil, oil shale, shale oil and oil sands, and preferably oil shale.

[0054] In some embodiments of the present invention, preferably, the biomass is selected from at least one of wood, forest waste, aquatic plants, oil plants and animal manure.

[0055] In some embodiments of the present invention, preferably, the solid waste is selected from at least one of plastics, waste oil, agricultural waste, waste food, and waste garbage.

[0056] In this invention, preferably, the method for catalytic pyrolysis of fossil energy, biomass, or solid waste includes:

[0057] (1) Under an atmosphere of inert gas, oxygen deficiency or non-oxidizing gas, the heteropolyacid modified metal-based solid acid catalyst is mixed with fossil energy, biomass or solid waste to obtain a mixture;

[0058] (2) The mixture is subjected to a pyrolysis reaction in an atmosphere of inert gas, oxygen deficiency or non-oxidizing gas.

[0059] In this invention, the catalytic pyrolysis method is beneficial to greatly reduce the activation energy of the pyrolysis reaction. By selectively altering the reaction pathway through the catalyst, the hydrocarbon content in the pyrolysis products is increased, the heteroatom content is reduced, the pyrolysis products are made lighter, and the content of high-value-added chemicals and high-quality petroleum-like fuels is increased.

[0060] In this invention, the mixing method has a wide range of options, as long as it can uniformly mix the heteropolyacid-modified metal-based solid acid catalyst with fossil energy, biomass, or solid waste. Preferably, the mixing method is selected from grinding and / or soaking.

[0061] In this invention, the mixing time is not particularly limited, as long as the heteropolyacid-modified metal-based solid acid catalyst is mixed evenly with fossil energy, biomass, or solid waste. Preferably, the mixing time is 0-72 hours, for example, it can be 0 hours, 1 hour, 2 hours, 3 hours, 6 hours, 12 hours, 18 hours, 24 hours, 30 hours, 32 hours, 72 hours, or any value within any two of the above ranges, preferably 0-4 hours.

[0062] In some embodiments of the present invention, preferably, the heteropolyacid-modified metal-based solid acid catalyst comprises heteropolyacid and boehmite. The heteropolyacid-modified metal-based solid acid catalyst is mixed in solid powder form with fossil fuels, biomass, or solid waste, and then ground to obtain an average particle size of 0.0001-1×10⁻⁶. 8 A mixture of μm particles. The average particle size of the fossil fuels, biomass or solid waste, and the heteropolyacid-modified metal-based solid acid catalyst is 0.0001-1×10⁻⁶. 4 μm, preferably 0.004-600μm.

[0063] In this invention, unless otherwise specified, when the pyrolysis reaction is carried out on land, there are certain requirements for the average particle size of the fossil-based energy source, biomass or solid waste, and the heteropolyacid-modified metal-based solid acid catalyst. Specifically, the average particle size of the fossil-based energy source, biomass or solid waste, and the heteropolyacid-modified metal-based solid acid catalyst is 0.0001-1×10⁻⁶. 5 μm, preferably 0.003-700 μm; when the pyrolysis reaction is carried out underground, there are no special requirements for the average particle size of the heteropolyacid modified metal-based solid acid catalyst. The main reason is that when the pyrolysis reaction is carried out underground, the underground ore is cracked mainly by underground explosion or fracturing. The particle size range of the ore can be hundreds of meters or even larger. This is equivalent to the formation of rocks of various sizes due to underground explosion. The heteropolyacid modified metal-based solid acid catalyst is attached to the surface of the rock that generates oil / gas dominant channels underground.

[0064] In some embodiments of the present invention, preferably, the weight ratio of the heteropolyacid-modified metal-based solid acid catalyst to fossil energy, biomass, or solid waste is 1:0.1-5000, more preferably 1:0.2-1000. In the present invention, the weight of the heteropolyacid-modified metal-based solid acid catalyst is based on the total weight of the heteropolyacid and boehmite. Controlling the above weight ratio within a specific range in the present invention is beneficial for ensuring a more complete pyrolysis reaction.

[0065] In some embodiments of the present invention, preferably, the temperature of the pyrolysis reaction is 0-800℃, for example 0℃, 50℃, 100℃, 200℃, 300℃, 400℃, 500℃, 600℃, 650℃, 700℃, 800℃, and any value within any two of the above ranges, preferably 200-600℃.

[0066] In some embodiments of the present invention, preferably, the pyrolysis reaction time is 0.00001s to 3 years, for example, 0.00001s, 0.0001s, 0.001s, 0.1s, 1s, 5s, 5min, 1h, 15h, 24h, 2 days, 50 days, 1 year, 2 years, 3 years, and any value within the range of any two of the above values, preferably 0.0001s to 24h.

[0067] In some embodiments of the present invention, preferably, the heating rate of the pyrolysis reaction is 0-1000℃ / s, for example 0℃ / s, 0.0001℃ / s, 0.01℃ / s, 0.1℃ / s, 1℃ / s, 5℃ / s, 10℃ / s, 50℃ / s, 200℃ / s, 300℃ / s, 400℃ / s, 500℃ / s, 1000℃ / s, and any value within any two of the above ranges, preferably 0-500℃ / s.

[0068] In this invention, controlling the conditions of the above-mentioned pyrolysis reaction within a specific range is beneficial to making the pyrolysis reaction more complete.

[0069] In this invention, unless otherwise specified, the heating rate parameter of the pyrolysis reaction depends on the heating method. When using the Curie point heating method, the heating rate can be as high as 8000℃ / s, while when using other heating methods, the heating rate can be as low as 0.0001℃ / s. Furthermore, when the pyrolysis reaction is carried out at an isothermal temperature, the heating rate is 0℃ / s.

[0070] In this invention, unless otherwise specified, the duration of the pyrolysis reaction depends on the specific conditions. If the pyrolysis reaction is carried out underground, the reaction time can be 0.5-3 years, or it can be several months or even a few days.

[0071] In some embodiments of the present invention, preferably, the inert gas is selected from at least one of helium, nitrogen, neon, argon, krypton and xenon, and preferably nitrogen.

[0072] In some embodiments of the present invention, preferably, the non-oxidizing gas is selected from at least one of methane, ethane, carbon monoxide, carbon dioxide, and hydrogen.

[0073] In this invention, preferably, the non-oxidizing gas or oxygen-deficient atmosphere is an underground oxygen-deficient environment.

[0074] In this invention, preferably, the pyrolysis reaction takes place above ground or underground.

[0075] In this invention, preferably, if the pyrolysis reaction is carried out in an underground environment, the heteropolyacid-modified metal-based solid acid catalyst is directly transported underground for reaction, or the heteropolyacid-modified metal-based solid acid catalyst is transported underground for reaction by a fluid load.

[0076] In this invention, the range of fluids is wide, and it can be a liquid or a gas, such as organic solvents, nitrogen, water, air, carbon dioxide, carbon monoxide, helium, and hydrogen.

[0077] The method provided by this invention employs a heteropolyacid-modified metal-based solid acid catalyst to conduct a pyrolysis reaction with fossil fuels (especially oil shale), biomass, or solid waste under an inert gas, non-oxidizing gas, or oxygen-deficient atmosphere. This method significantly reduces the activation energy of the pyrolysis reaction. By selectively altering the reaction pathway through the catalyst, the hydrocarbon content in the pyrolysis products is increased, the heteroatom content is reduced, and the pyrolysis products are made lighter, thereby increasing the content of high-value-added chemicals and high-quality petroleum-like fuels.

[0078] In this invention, the aforementioned method can be used to catalytically pyrolyze fossil fuels, biomass, or solid waste, or a two-stage processing and treatment method can be used to catalytically pyrolyze fossil fuels, biomass, or solid waste. Preferably, a two-stage processing and treatment method is used to catalytically pyrolyze fossil fuels, biomass, or solid waste. More preferably, the two-stage catalytic pyrolysis method for fossil fuels, biomass, or solid waste includes: contacting a heteropolyacid-modified metal-based solid acid catalyst with fossil fuels, biomass, or solid waste in an oxygen-deficient, non-oxidizing gas, or inert gas atmosphere, and carrying out a pyrolysis reaction on the fossil fuels through a first stage and a second stage to obtain pyrolysis products;

[0079] The temperature in the first stage is lower than the temperature in the second stage.

[0080] In this invention, preferably, the temperature of the first stage is 50-500℃, for example, 50℃, 150℃, 200℃, 250℃, 300℃, 350℃, 400℃, 460℃, 500℃, and any value within the range of any two of the above values, preferably 200-460℃.

[0081] In this invention, preferably, the temperature of the second stage is 200-700℃, for example, 200℃, 260℃, 300℃, 350℃, 400℃, 450℃, 500℃, 550℃, 600℃, 700℃, and any value within the range of any two of the above values, preferably 260-600℃.

[0082] In this invention, preferably, the time of the first stage and the second stage are each independently between 0.00001s and 3 years, for example, 0.00001s, 0.0001s, 0.01s, 0.1s, 0.5s, 1s, 2s, 6s, 10s, 1min, 6min, 1h, 6h, 12h, 24h, 100 days, 1 year, 2 years, 3 years, and any value within the range of any two of the above values, preferably between 0.0001s and 24h.

[0083] In this invention, preferably, the heating rate of the pyrolysis reaction is 0-1000℃ / s, for example, 0℃ / s, 0.0001℃ / s, 0.01℃ / s, 0.1℃ / s, 1℃ / s, 5℃ / s, 10℃ / s, 50℃ / s, 200℃ / s, 300℃ / s, 400℃ / s, 500℃ / s, 1000℃ / s, and any value within any two of the above ranges, preferably 0-500℃ / s.

[0084] In this invention, controlling the conditions of the first and second stages within the specific ranges described above is beneficial for making the pyrolysis reaction more complete.

[0085] In this invention, a heteropolyacid-modified metal-based solid acid catalyst is used as the catalyst to catalytically pyrolyze fossil fuels, biomass, or solid waste in an inert, oxygen-deficient, or non-oxidizing gas atmosphere through two stages at lower and higher temperatures. Depending on the pyrolysis temperature, at lower temperatures, high-quality petroleum-like fuels (especially thiophene and pyrrole, two types of five-membered heterocyclic aromatic hydrocarbons) are produced through catalytic pyrolysis. At higher temperatures, it is beneficial to remove heteroatom compounds, increase hydrocarbons, increase the content of short-chain (≤C13) and medium-chain (C14-C19) aliphatic hydrocarbons, and reduce the content of long-chain (≥C20) aliphatic hydrocarbons, producing high-value-added chemicals (especially thiophene compounds, pyrrole compounds, α-olefins, and dienes).

[0086] The present invention will be described in detail below through embodiments.

[0087] Example 1

[0088] The chemical formula is H3PW 12 O 40 / γ-AlOOH(H3PW 12 O 40 Morphological analysis was performed on the heteropolyacid-modified metal-based solid acid catalyst (mass ratio of γ-AlOOH: 1:5.7). The scanning electron microscope (SEM) image of the above heteropolyacid-modified metal-based solid acid catalyst is shown in Figure A1. Figure 1 As can be seen from A, the above-mentioned heteropolyacid-modified metal-based solid acid catalysts are irregular nanoparticles with a diameter of approximately 50-150 nm; the transmission electron microscope (TEM) images of the above-mentioned heteropolyacid-modified metal-based solid acid catalysts and... Figure 1 As shown in Figure B, the energy dispersive spectroscopy (EDS) spectrum of the above-mentioned heteropolyacid modified metal-based solid acid catalyst is as follows: Figure 1 C to Figure 1 As shown in F, by Figure 1 B and Figure 1 C to Figure 1 As can be seen from F, Al, O, P and W elements are uniformly distributed in the corresponding nanostructure profiles, indicating that the above-mentioned heteropolyacid modified metal-based solid acid catalyst is a nano-hybrid with uniformly distributed elements.

[0089] The X-ray diffraction (XRD) patterns of the above-mentioned heteropolyacid modified metal-based solid acid catalysts are shown below. Figure 2 As shown in A, by Figure 2 As can be seen from A, the diffraction peaks of this catalyst match well with those of boehmite (JCPDS No. 21-1307), and no other characteristic peaks appear, indicating that phosphotungstic acid is uniformly distributed on the surface of boehmite; the Fourier transform infrared (FTIR) spectrum of the above heteropolyacid-modified metal-based solid acid catalyst is shown in Figure A. Figure 2 As shown in B, by Figure 2 As can be seen from B, the catalyst contains characteristic vibrational peaks of Al-O bonds, OH bonds, PO bonds, WOW bonds, and adsorbed water, indicating that the catalyst contains phosphotungstic acid species with a typical Keggin structure and coordinated unsaturated Al. 3+ The presence of species and mobile protons suggests that the catalyst may have both L and B acid sites.

[0090] The above-mentioned heteropolyacid-modified metal-based solid acid catalyst was characterized by pyridine adsorption using Fourier transform infrared spectroscopy (Py-FTIR) to verify the presence of acid sites on its surface. The Py-FTIR spectra of the above-mentioned heteropolyacid-modified metal-based solid acid catalyst are shown in the figure below. Figure 3 As shown, at a desorption temperature of 200℃, at a depth of 1540 cm⁻¹-1 The vibrational peak near the site is the L acid site, at 1490 cm⁻¹. -1 The vibrational peak near the 1490 cm⁻¹ is the Brønsted acid site. -1 The vibrational peak at the point is the site of interaction between Brønsted (B) acid and Lewis (L) acid, indicating the presence of both Brønsted (B) and Lewis (L) acid sites in the aforementioned heteropolyacid-modified metal-based solid acid catalyst. Quantitative acid content analysis showed a total Brønsted (B) acid concentration of 57.8 μmol / g, a total Lewis (L) acid concentration of 28.9 μmol / g, a moderately strong Brønsted (B) acid concentration of 40.8 μmol / g, and a moderately strong Lewis (L) acid concentration of 15.6 μmol / g. This indicates that the concentration / strength of Brønsted (B) acid in the aforementioned heteropolyacid-modified metal-based solid acid catalyst is significantly higher / stronger than that of Lewis (L) acid. Therefore, the synergistic and competitive effects of Brønsted (B) acid and Lewis (L) acid in the aforementioned heteropolyacid-modified metal-based solid acid catalyst may guide the thermochemical conversion reaction of oil shale preferentially along specific pathways, endowing the heteropolyacid-modified metal-based solid acid catalyst with excellent catalytic performance.

[0091] To evaluate the effect of heteropolyacid-modified metal-based solid acid catalysts on the activation energy of oil shale pyrolysis, thermogravimetric (TG) analysis experiments were conducted with and without the participation of heteropolyacid-modified metal-based solid acid catalysts. Figure 4 A and Figure 4 B represents the TG and DTG curves of the oil shale pyrolysis system with heteropolyacid-modified metal-based solid acid catalyst and the original oil shale pyrolysis system without heteropolyacid-modified metal-based solid acid catalyst at a heating rate of 20 K / min, respectively. Figure 4 C and Figure 4 D represents the TG and DTG curves of the oil shale pyrolysis system with heteropolyacid-modified metal-based solid acid catalyst and the original oil shale pyrolysis system without heteropolyacid-modified metal-based solid acid catalyst at different heating rates (10–30 K / min), respectively. Figure 4 A to Figure 4 As can be seen from D, the overall weight loss of the heteropolyacid-modified metal-based solid acid catalyst increases after participating in the pyrolysis of oil shale, and the maximum pyrolysis rate temperature is advanced. This indicates that the catalyst can be used as a catalyst to promote the pyrolysis of oil shale.

[0092] Based on TG analysis, the catalytic performance of the above-mentioned heteropolyacid-modified metal-based solid acid catalyst for the pyrolysis of oil shale was evaluated using the FWO method. The approximate equation for the FWO method is shown in equation (1). Activation energy analysis data are as follows: Figure 5 As shown in A-5C, where... Figure 5 A is a linear regression diagram of the oil shale pyrolysis system with a heteropolyacid-modified metal-based solid acid catalyst, fitted based on the FWO approximation equation. Figure 5 B is a linear regression diagram of the oil shale pyrolysis system without heteropolyacid modified metal-based solid acid catalysts, fitted based on the FWO approximation equation; Figure 5C is a distribution diagram of Eα as a function of α in different oil shale pyrolysis systems obtained based on the FWO method. Figure 5 C indicates that the activation energy of the reaction decreased by 11.2% after introducing the above-mentioned heteropolyacid-modified metal-based solid acid catalyst.

[0093]

[0094] Figure 6 A shows the Py-EGA-MS chromatograms of different oil shale pyrolysis systems. The Py-EGA-MS curves indicate that oil shale pyrolysis produces two peaks: the first peak (the preceding peak) corresponds to the pyrolysis of organic matter, and the second peak (the following peak) corresponds to the pyrolysis of inorganic matter. After introducing the aforementioned heteropolyacid-modified metal-based solid acid catalyst, the highest point of the organic matter peak shifts significantly to the low-temperature region, and the peak intensity of the total ion chromatogram increases. Figure 6 As shown in Figure B, the products generated from the first peak region can be clearly distinguished into mass fragments with m / z = 41+14n (n = 0, 1, 2, 3, etc.) and 43+14n (n = 0, 1, 2, 3, etc.), which are typically characteristic ionic fragments of aliphatic hydrocarbons. Simultaneously, ionic fragments with m / z of 109 and 95 are also observed, which are typically fragments of aromatic compounds, as well as an ionic fragment with m / z = 81, which can be attributed to fragments of alkyl-substituted cyclohexenes. Figure 6 C is the MS plot obtained from the products generated in the second peak region of different oil shale pyrolysis systems, as shown in the figure. Figure 6 As shown in Figure C, the products extracted in the second peak region yielded signals with m / z values ​​of 44, 28, and 16, which are typical MS signals for CO2. This indicates that the aforementioned heteropolyacid-modified metal-based solid acid catalyst can improve the conversion rate, enabling more organic matter to be converted into oil and gas products.

[0095] To further explore the catalytic performance of the above-mentioned heteropolyacid modified metal-based solid acid catalyst for oil shale pyrolysis, the distribution of pyrolysis products was analyzed by rapid pyrolysis gas chromatography-mass spectrometry. The non-catalytic and catalytic systems of oil shale underwent two-stage pyrolysis reactions at lower (453℃) and higher (600℃) temperatures, respectively. Figure 7 A and 7B are the total ion current chromatograms (TIC) of the reaction products before and after catalytic pyrolysis of oil shale at low and high temperatures, respectively. Figure 7 As can be seen from A and 7B, after the above-mentioned heteropolyacid-modified metal-based solid acid catalysts participate in the pyrolysis reaction of oil shale, the intensity and number of chromatographic peaks of the pyrolysis products are significantly increased.

[0096] Figure 8 A to Figure 8 A schematic diagram illustrating the distribution of components in the products obtained from the pyrolysis reactions of different oil shale pyrolysis systems at a low temperature (453℃). Figure 8 A to Figure 8As can be seen from G, after introducing the above-mentioned heteropolyacid-modified metal-based solid acid catalyst, the content of hydrocarbon compounds increased from 37.1% to 51.6%, and the content of heteroatom compounds decreased from 62.9% to 48.4%. Further analysis of heteroatom compounds showed that the content of oxygen-containing compounds decreased from 43.1% to 14.3%, the content of nitrogen-containing compounds decreased from 8.1% to 8.0%, and the content of sulfur-containing compounds increased from 19.3% to 26.8%. Among nitrogen-containing compounds, the content of amine compounds decreased from 5.2% to 1.0%, and the content of pyrrole compounds increased from 2.9% to 6.9%. Among sulfur-containing compounds, the content of non-thiophene compounds such as sulfides, sulfones, and thiols decreased from 7.4% to 0.8%, and the content of thiophene compounds increased from 11.9% to 26.0%. This indicates that the aforementioned heteropolyacid-modified metal-based solid acid catalysts possess deoxygenation, denitrification, and desulfurization capabilities at lower temperatures, and promote the detachment of pyrrole and thiophene compound structures from the kerogen skeleton of oil shale, generating more pyrrole and thiophene compounds. Both of these compounds are high-value-added five-membered heterocyclic aromatic hydrocarbon scaffolds / building blocks, and are widely used in many critical scientific and technological fields, such as pharmaceuticals, organic light-emitting diodes, thin-film transistors, nonlinear optical polymers, sensors, optoelectronic devices, and other related fields. After introducing the aforementioned heteropolyacid-modified metal-based solid acid catalyst, the contents of alkanes, olefins, and aromatics decreased from 11.0% to 10.1%, increased from 16.4% to 24.7%, and increased from 7.9% to 12.5%, respectively. Specifically, the content of monocyclic aromatics increased from 5.2% to 12.1%, while the content of polycyclic aromatics decreased from 2.7% to 0.4%. This demonstrates that the aforementioned heteropolyacid-modified metal-based solid acid catalyst exhibits high selectivity for monocyclic aromatics and possesses certain anti-coking properties, as polycyclic aromatics are typically precursors to coking. Further analysis of the carbon number distribution showed that the contents of short-chain (≤C13) and medium-chain (C14-C19) aliphatic hydrocarbons increased from 19.9% ​​to 35.7% and from 8.9% to 14.6%, respectively, while the content of long-chain (≥C20) aliphatic hydrocarbons decreased from 8.3% to 1.3%, which is beneficial for making the oil product lighter.

[0097] Figure 9 A- Figure 9 G is a schematic diagram showing the distribution of components in the products obtained from the pyrolysis reaction of different oil shale pyrolysis systems at high temperature (600℃). Figure 9 A to Figure 9As can be seen from G, after introducing the above-mentioned heteropolyacid-modified metal-based solid acid catalyst, the hydrocarbon content increased from 54.8% to 78.3%, while the heteroatom content decreased from 45.2% to 21.7%. Further analysis of heteroatom compounds showed that the oxygen-containing compound content decreased from 35.2% to 16.4%, the nitrogen-containing compound content decreased from 0.7% to 0.3%, and the sulfur-containing compound content decreased from 9.6% to 5.0%, indicating that the catalyst has excellent heteroatom removal capabilities at higher temperatures. After introducing the aforementioned heteropolyacid-modified metal-based solid acid catalyst, the contents of alkanes, alkenes, and aromatics decreased from 10.5% to 9.6%, increased from 19.6% to 35.9%, and increased from 14.0% to 23.7%, respectively. Further analysis of olefins showed that the contents of α-olefins and dienes increased from 13.6% to 31.0% and from 2.4% to 7.9%, respectively, representing increases of 127.9% and 229.2%. This provides a simple scheme for producing α-olefins and dienes from oil shale using the aforementioned heteropolyacid-modified metal-based solid acid catalyst via pyrolysis. α-olefins and dienes are important high-value-added basic precursors / constructors, widely used in the manufacture of many complex functional materials and multifunctional polymers. Therefore, they are widely used in high-functional molecules (such as aldehydes, surfactants, fatty acids, alcohols, etc.), plastics, elastomers, fibers, rubber, and organic semiconductors. Furthermore, the content of monocyclic aromatic hydrocarbons increased from 9.7% to 21.4%, while the content of polycyclic aromatic hydrocarbons decreased from 4.3% to 2.3%. This demonstrates that the aforementioned heteropolyacid-modified metal-based solid acid catalyst exhibits high selectivity for monocyclic aromatic hydrocarbons and possesses certain anti-coking properties. The carbon number distribution trend is consistent with that observed at lower temperature catalytic pyrolysis. All of this indicates that the aforementioned heteropolyacid-modified metal-based solid acid catalyst can catalyze the pyrolysis of oil shale to produce light petroleum fuels and high-value-added chemicals.

[0098] In summary, using the heteropolyacid-modified metal-based solid acid catalyst provided by this invention as a catalyst for the catalytic decomposition reaction of oil shale reduces the activation energy of oil shale pyrolysis by 11.2%. This metal-based solid acid effectively reduces the reaction activation energy and improves product distribution, while also exhibiting a certain degree of anti-coking ability. Furthermore, depending on the pyrolysis reaction temperature, high-value-added chemicals such as thiophene, pyrrole, α-olefins, and dienes can be produced.

[0099] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A heteropolyacid-modified metal-based solid acid catalyst, characterized in that, The heteropolyacid metal-based solid acid catalyst includes heteropolyacids and boehmite.

2. The heteropolyacid-modified metal-based solid acid catalyst according to claim 1, wherein, In the heteropolyacid modified metal-based solid acid catalyst, the total Brønsted acid concentration is 0.01-10000 μmol / g, preferably 1-1000 μmol / g; the total Lewis acid concentration is 0.01-10000 μmol / g, preferably 1-1000 μmol / g. Preferably, in the heteropolyacid modified metal-based solid acid catalyst, the concentration of the medium-strength Brønsted acid is 0.01-10000 μmol / g, more preferably 1-1000 μmol / g, and the concentration of the medium-strength Leucine acid is 0.01-10000 μmol / g, more preferably 1-1000 μmol / g.

3. The heteropolyacid-modified metal-based solid acid catalyst according to claim 1 or 2, wherein, The mass ratio of the heteropolyacid to boehmite is 1:0.05-18, preferably 1:1-10, and more preferably 1:4-7.

4. The heteropolyacid-modified metal-based solid acid catalyst according to any one of claims 1-3, wherein, The heteropolyacid includes heteroatoms and polyatoms; the heteroatoms are selected from at least one of the metal elements of Group IIIA, Group IVA, Group VA and Group VIII of the third period, and preferably from at least one of P, Si, Fe and Co; Preferably, the polyatomic element is selected from Group VB metal elements and / or Group VIIB metal elements, and more preferably from at least one of Mo, W, V, Nb and Ta; Preferably, the heteropolyacid has a keggin structure; Preferably, the heteropoly acid is phosphotungstic acid; Preferably, the chemical formula of the catalyst is (H3PW) 12 O 40 ) m / (γ-AlOOH) n , where n≠0, m≠0.

5. The application of the heteropolyacid modified metal-based solid acid catalyst according to any one of claims 1-4 in the processing and treatment of fossil energy, biomass or solid waste.

6. The application according to claim 5, wherein, The fossil energy source is selected from at least one of coal, petroleum, heavy oil, oil shale, shale oil and oil sands, preferably oil shale; Preferably, the biomass is selected from at least one of wood, forest waste, aquatic plants, oil plants and animal manure; Preferably, the solid waste is selected from at least one of plastics, waste oil, agricultural waste, waste food, and waste garbage.

7. A method for catalytic pyrolysis of fossil fuels, biomass, or solid waste, characterized in that, The method comprises: contacting the heteropolyacid modified metal-based solid acid catalyst according to any one of claims 1-4 with fossil energy, biomass or solid waste and carrying out a pyrolysis reaction under an inert gas, oxygen-deficient or non-oxidizing gas atmosphere to obtain pyrolysis products.

8. The method according to claim 7, wherein, The weight ratio of the heteropolyacid modified metal-based solid acid catalyst to fossil energy, biomass or solid waste is 1:1:0.1-5000, preferably 1:0.2-1000.

9. The method according to claim 7 or 8, wherein, The inert gas is selected from at least one of helium, nitrogen, neon, argon, krypton and xenon, preferably nitrogen; Preferably, the non-oxidizing gas is selected from at least one of methane, ethane, carbon monoxide, carbon dioxide, and hydrogen. Preferably, the fossil energy source is selected from at least one of coal, petroleum, heavy oil, oil shale, shale oil, and oil sands, with oil shale being the most preferred. Preferably, the biomass is selected from at least one of wood, forest waste, aquatic plants, oil plants and animal manure; Preferably, the solid waste is selected from at least one of plastics, waste oil, agricultural waste, waste food, and waste garbage.

10. The method according to any one of claims 7-9, wherein, The pyrolysis reaction conditions include: a temperature of 0-800℃, preferably 200-600℃; a time of 0.00001s-3 years, preferably 0.0001s-24h; and a heating rate of 0-1000℃ / s, preferably 0-500℃ / s.

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