Method for pyrolysis of medium-low mature shale oil and oil shale catalyzed by ferrocene

Abstract

The present application relates to a kind of ferrocene catalytic middle-low mature shale oil and oil shale pyrolysis method, the method includes the following steps: first, shale powder, solid ferrocene catalyst and solvent are mixed and dried, to obtain solid phase mixture;The oil and gas product is obtained after the solid phase mixture is pyrolyzed;The method uses solid ferrocene catalyst to catalyze shale pyrolysis, improves the pyrolysis efficiency of shale, and shale oil recovery is as high as 0.41% or more, shale gas recovery is as high as 7.72% or more, and the heavy oil yield in the shale oil is lower, and the proportion of middle-low carbon hydrocarbon gas in the shale gas is higher, which provides a new method for efficient development of middle-low mature shale oil and oil shale resources.

Description

Technical Field

[0001] This invention relates to the field of oil and gas extraction technology, and in particular to a method for ferrocene-catalyzed pyrolysis of medium- and low-maturity shale oil and oil shale. Background Technology

[0002] In recent years, with rapid economic development, domestic demand for crude oil has been increasing. However, the country's dependence on imported oil remains high. Therefore, finding alternative oil resources and reducing dependence on foreign oil has become an urgent issue. China possesses abundant reserves of medium- and low-maturity shale oil and oil shale resources, with high oil and gas recovery rates (over 50%) and enormous resource scale, making them the most promising oil and gas resources. Therefore, adopting efficient methods to develop medium- and low-maturity shale oil and oil shale is of great significance in alleviating the pressure on oil resource supply.

[0003] In-situ underground thermal conversion technology is the main technology for the industrial-scale extraction of medium- and low-maturity shale oil and oil shale. It utilizes underground artificial heating to degrade various organic compounds retained in shale, converting solid organic matter (kerogen) into liquid petroleum hydrocarbons and natural gas. However, the high energy consumption of in-situ underground electric heating is currently a key factor restricting the economic viability of shale oil extraction. The introduction of pyrolysis catalysts can lower the reaction activation energy and promote the cracking of organic matter, thereby effectively reducing the overall energy consumption of extraction and improving the pyrolysis efficiency of kerogen and the oil and gas recovery rate.

[0004] However, most of the catalysts developed so far are solid catalysts. Due to the size of pore throats in shale (≤30nm), the diffusion and transport of solid catalyst systems in the formation are severely limited, failing to meet the requirements of in-situ conversion injection. Although liquid catalysts can meet the injection requirements, their thermal stability is poor, and they suffer from insufficient stability under high formation temperatures (400℃), resulting in a lack of sustained effectiveness.

[0005] For example, CN109424345B discloses a method for in-situ mining of oil shale. In this method, a proppant containing magnetic nanocatalysts is injected into the oil shale reservoir. This involves precious metals (Pt, Pd, or Ni) as catalyst components, resulting in high costs. Moreover, due to factors such as the complex fractures and high-temperature and high-pressure environment of the oil shale reservoir, the magnetic nanocatalysts have poor stability and are relatively difficult to recover, leading to a decrease in the in-situ catalytic conversion capacity and environmental impact.

[0006] For example, CN120054509A discloses an iron-based catalyst for in-situ exploitation of oil shale, its preparation method and application. This iron-based catalyst exists in emulsion form, which requires a long oil and gas recovery time and has a relatively low oil recovery rate under the same time conditions. Moreover, it has poor stability in high temperature and complex underground environments and is prone to deactivation under high temperature and high pressure, requiring regular replacement or regeneration.

[0007] Therefore, how to develop a novel in-situ catalyst with advantages such as good diffusivity and high temperature resistance for efficient catalytic pyrolysis of medium- and low-maturity shale oil and / or medium- and low-maturity oil shale, so as to realize the full utilization of shale resources, is an urgent problem to be solved in this field. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a method for the pyrolysis of medium- and low-maturity shale oil and oil shale catalyzed by ferrocene. This method promotes the pyrolysis of shale and oil shale in medium- and low-maturity oil shale, achieving efficient in-situ conversion of organic matter, improving oil and gas recovery rates, and significantly reducing the heavy oil content in the resulting shale oil and the proportion of low- and medium-carbon hydrocarbon components in the resulting shale gas. This method solves the problem of poor catalyst diffusivity and poor high-temperature resistance in existing technologies, which hinders the full catalytic pyrolysis of shale. It provides a novel in-situ catalyst for the catalytic pyrolysis of medium- and low-maturity shale oil or oil shale.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] This invention provides a method for the pyrolysis of medium- and low-maturity shale oil and oil shale using ferrocene catalysis, the method comprising the following steps:

[0011] (1) Shale powder, solid ferrocene catalyst and solvent are mixed and dried to obtain a solid mixture;

[0012] (2) After the solid mixture described in step (1) is subjected to a pyrolysis reaction, oil and gas products are obtained.

[0013] The solid ferrocene catalyst is a type of Fe... 2+ Organometallic compounds formed between two cyclopentadienyl groups, exhibiting a layered sandwich structure and exposed Fe... 2+ With abundant active sites, a unique electronic structure, and thermal stability, it exhibits excellent performance in catalysis. The π electrons of the cyclopentadienyl group form a conjugated system with the d orbitals of iron atoms, giving it strong Lewis acidity and synergistic catalytic activity. Due to its molecular symmetry and low polarity, it maintains a stable structure at high temperatures, with a thermal decomposition temperature reaching approximately 470℃, and even higher decomposition temperatures under high pressure, meeting the stringent requirements of shale catalytic pyrolysis. Secondly, the coordination ability of the cyclopentadienyl group can adsorb metallic impurities in shale, inhibiting coking and carbon deposition. Thirdly, ferrocene itself possesses low toxicity and low cost, meeting the demands of green catalysis.

[0014] It is worth noting that the shale powder described in this invention includes shale powder from medium- and low-maturity shale oil and / or oil shale powder.

[0015] The pyrolysis reaction described in this invention is carried out in a high-pressure closed environment, such as a high-pressure closed reactor.

[0016] More importantly, the solid ferrocene catalyst can sublimate at temperatures above 100°C and easily transforms into a gaseous catalyst at high temperatures, which facilitates its diffusion in the fissures of underground shale and thus promotes the catalytic pyrolysis of shale.

[0017] This invention utilizes the aforementioned solid ferrocene catalyst to effectively reduce the pyrolysis temperature of shale, improve pyrolysis efficiency, and significantly improve oil and gas recovery rate. Furthermore, the recovered shale oil and shale gas are of high quality, solving the problems of low pyrolysis efficiency and high heavy oil yield caused by the difficulty in catalyst injection or its easy failure at high temperatures in existing technologies.

[0018] Preferably, the vitrinite reflectance of the shale powder in step (1) is 0.6% to 1.1%, for example, it can be 0.6%, 0.7%, 0.8%, 0.9%, 1.0% or 1.1%.

[0019] Preferably, the shale powder in step (1) has a particle size of <60 mesh, for example, it can be 58 mesh, 55 mesh, 52 mesh, 50 mesh, 48 mesh or 45 mesh, etc.

[0020] Preferably, the microstructure of the solid ferrocene catalyst in step (1) includes a combination of needle-like and rod-like structures.

[0021] Preferably, the thermal decomposition temperature of the solid ferrocene catalyst in step (1) is 450 to 490°C, for example, it can be 450°C, 460°C, 465°C, 470°C, 480°C or 490°C.

[0022] Preferably, the solvent in step (1) includes a volatile solvent.

[0023] Preferably, the volatile solvent includes any one or a combination of at least two of ethanol, dichloromethane, or water, wherein typical but non-limiting combinations include a combination of ethanol and dichloromethane, a combination of ethanol and water, or a combination of dichloromethane and water.

[0024] Preferably, the amount of solid ferrocene catalyst added in step (1) is 0.1% to 1.0% of the total mass of the shale powder, for example, it can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% or 1.0%, and preferably 0.3% to 0.5%.

[0025] In a further preferred embodiment of the present invention, the amount of solid ferrocene catalyst added in step (1) is 0.3% to 0.5% of the total mass of the rock powder, which is beneficial to further improve the pyrolysis efficiency of shale, resulting in a higher oil and gas recovery rate and further improving the quality of the obtained oil and gas. If the amount of solid ferrocene catalyst added in step (1) is too small, the pyrolysis efficiency of shale will decrease, and the oil and gas recovery rate and its quality will decline. If the amount of solid ferrocene catalyst added in step (1) is too large, it will not significantly improve the oil and gas recovery rate and its quality, but will instead increase the pyrolysis cost.

[0026] Preferably, the mass-to-volume ratio of the solid ferrocene catalyst to the solvent in step (1) is 1:(3-15) g / L, for example, it can be 1:3 g / L, 1:5 g / L, 1:8 g / L, 1:10 g / L, 1:12 g / L or 1:15 g / L, etc.

[0027] Preferably, the mixing in step (1) includes first mixing the solid ferrocene catalyst with the solvent to obtain a ferrocene catalyst solution, and then mixing the ferrocene catalyst solution with the shale powder.

[0028] Preferably, the first mixing includes ultrasonic mixing.

[0029] Preferably, the ultrasonic power of the ultrasonic mixture is 100-200W, for example, it can be 100W, 120W, 150W, 160W, 180W or 200W.

[0030] Preferably, the second mixing involves impregnating the ferrocene catalyst solution by dripping it onto the shale powder.

[0031] Preferably, the drying temperature in step (1) is ≤60℃, for example, it can be 40℃, 45℃, 50℃, 55℃ or 60℃, preferably 50~60℃.

[0032] The present invention further prefers that the drying temperature in step (1) is 50-60°C, which is beneficial to remove ethanol in the system and avoid ferrocene sublimation; if the drying temperature in step (1) is too low, the drying time will be too long, increasing the time cost and reducing efficiency; if the drying temperature in step (1) is too high, ferrocene will sublimate, reducing the catalyst content in the system.

[0033] Preferably, the drying time in step (1) is 9 to 15 minutes, for example, 9 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes or 15 minutes.

[0034] Preferably, the pyrolysis reaction in step (2) is carried out in a closed environment filled with protective gas.

[0035] Preferably, the protective gas includes nitrogen and / or argon.

[0036] Preferably, the initial pressure of the pyrolysis reaction is 0.5 to 5 MPa, for example, it can be 0.5 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa, 4 MPa, 4.5 MPa or 5 MPa, and is preferably 0.5 to 3 MPa.

[0037] The present invention further preferably uses an initial pressure of 0.5-3 MPa for the pyrolysis reaction, which is beneficial to improving the pyrolysis efficiency of shale and increasing the oil and gas recovery rate and quality. If the initial pressure of the pyrolysis reaction is low, the shale oil recovery rate can be further improved. If the initial pressure of the pyrolysis reaction is high, the shale oil will decompose further due to the high internal pressure of the reaction, resulting in a decrease in the shale oil recovery rate.

[0038] Preferably, the temperature of the pyrolysis reaction is 350 to 550°C, for example, it can be 350°C, 380°C, 400°C, 420°C, 450°C, 480°C, 500°C, 520°C or 550°C.

[0039] Preferably, the pyrolysis reaction takes 2 to 4 hours, for example, 2 hours, 2.5 hours, 3 hours, 3.5 hours, or 4 hours.

[0040] As a further preferred technical solution of the present invention, the pyrolysis method includes the following steps:

[0041] (1) First, the solid ferrocene catalyst and the solvent are ultrasonically mixed at a mass-to-volume ratio of 1:(3~15)g / L to obtain a ferrocene catalyst solution. The ultrasonic power of the ultrasonic mixing is 100~200W. Then, the ferrocene catalyst solution is added dropwise to the shale powder for impregnation. After that, it is dried at a temperature of ≤60℃ for 9~15min to obtain a solid mixture.

[0042] (2) In a closed environment filled with protective gas at 350-550℃ and an initial pressure of 0.5-5MPa, the solid mixture in step (1) undergoes a pyrolysis reaction for 2-4 hours to obtain oil and gas products.

[0043] Wherein, the vitrinite reflectance of the shale powder in step (1) is 0.6 to 1.1%; the particle size of the shale powder in step (1) is <60 mesh; and the amount of solid ferrocene catalyst added in step (1) is 0.1% to 1.0% of the total mass of the shale powder.

[0044] The microstructure of the solid ferrocene catalyst in step (1) includes a combination of needle-like and rod-like structures; the thermal decomposition temperature of the solid ferrocene catalyst in step (1) is 450-490℃; the solvent in step (1) includes a volatile solvent; the volatile solvent includes any one or a combination of at least two of ethanol, dichloromethane or water.

[0045] Compared with the prior art, the present invention has at least the following beneficial effects:

[0046] The present invention provides a method for pyrolysis of medium- and low-maturity shale oil and oil shale using ferrocene catalyst. This method utilizes a solid ferrocene catalyst to catalyze the pyrolysis reaction. The catalyst leverages its excellent thermal stability, abundant active sites, and the characteristic of sublimating into a gaseous catalyst above 100°C, making it easier to diffuse and fully contact with the shale. This promotes efficient in-situ conversion of organic matter in the shale at high temperatures. Furthermore, the method optimizes parameters such as the amount of solid ferrocene catalyst added and the initial pressure of the pyrolysis reaction, resulting in a shale oil recovery rate preferably above 0.41% and a shale gas recovery rate preferably above 7.69%. The method also reduces the heavy oil yield in the obtained shale oil and increases the proportion of low- and medium-carbon hydrocarbon components in the obtained shale gas, achieving full conversion and utilization of shale resources. Attached Figure Description

[0047] Figure 1 This is a SEM image of the solid ferrocene catalyst described in this invention;

[0048] Figure 2 This is the XRD pattern of the solid ferrocene catalyst described in this invention;

[0049] Figure 3 This is the infrared spectrum of the solid ferrocene catalyst described in this invention;

[0050] Figure 4 This is a comparison chart of oil and gas recovery rates and their recovery enhancement rates obtained by the methods described in Examples 1, 4, 5, 8, 9 and Comparative Example 2 of this invention;

[0051] Figure 5 This is a comparison chart of the components and contents of shale oil obtained by the methods described in Examples 1, 4, 5 and 9 of this invention;

[0052] Figure 6 This is a comparison chart of the components and contents of shale gas obtained by the methods described in Examples 1, 4, 5, 8, 9 and Comparative Example 2 of this invention. Detailed Implementation

[0053] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0054] The solid ferrocene catalyst used in the following examples or comparative examples was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., with a purity >98%.

[0055] The pyrolysis reactions described in the following examples or comparative examples are carried out in a closed reactor at a pressure of 0.5–5 MPa.

[0056] I. Implementation Examples

[0057] Example 1

[0058] This embodiment provides a method for the pyrolysis of medium- and low-maturity shale oil and oil shale using ferrocene catalysis, the method comprising the following steps:

[0059] (1) First, the solid ferrocene catalyst and the anhydrous ethanol are ultrasonically mixed at a mass-to-volume ratio of 1:10 g / L to obtain a ferrocene catalyst solution. The ultrasonic power of the ultrasonic mixing is 150 W. Then, the ferrocene catalyst solution is added dropwise to the shale powder (shale powder in medium-low maturity shale oil) for impregnation. After that, it is dried at 55°C for 12 min to obtain a solid mixture.

[0060] (2) In a closed reactor filled with nitrogen at 450℃ and an initial pressure of 2MPa, the solid mixture described in step (1) is pyrolyzed for 3 hours to obtain oil and gas products.

[0061] Wherein, the vitrinite reflectance of the shale powder in step (1) is 0.6%; the particle size of the shale powder in step (1) is <60 mesh; the amount of solid ferrocene catalyst added in step (1) is 0.3% of the total mass of the shale powder; and the thermal decomposition temperature of the solid ferrocene catalyst in step (1) is 470℃.

[0062] like Figure 1 As shown, the microstructure of the solid ferrocene catalyst in step (1) includes a combination of needle-like and rod-like structures, which are interwoven and distributed.

[0063] like Figure 2 As shown in the XRD pattern of the solid ferrocene catalyst in step (1), the characteristic peaks are obvious and no impurity peaks appear, indicating that the solid ferrocene catalyst has high purity and good crystallinity.

[0064] like Figure 3As shown in the infrared spectrum of the solid ferrocene catalyst described in step (1), it can be seen that the concentration of the catalyst in the range of 1450–1560 cm⁻¹ is [missing information]. -1 A strong absorption peak appears within the range of 500–600 cm⁻¹, corresponding to the stretching vibration of the conjugated double bond (C=C); -1 Characteristic absorption peaks were detected, reflecting the coordination interaction between iron atoms and the cyclopentadiene ring; in the range of 700–900 cm⁻¹ -1 A weak absorption peak was observed within the range, corresponding to ring bending vibration, and no other characteristic peaks of irrelevant functional groups were detected.

[0065] Example 2

[0066] This embodiment provides a method for the pyrolysis of medium- and low-maturity shale oil and oil shale using ferrocene catalysis, the method comprising the following steps:

[0067] (1) First, the solid ferrocene catalyst and the anhydrous ethanol are ultrasonically mixed at a mass-to-volume ratio of 1:5 g / L to obtain a ferrocene catalyst solution. The ultrasonic power of the ultrasonic mixing is 100 W. Then, the ferrocene catalyst solution is added dropwise to the shale powder (oil shale powder) for impregnation. After that, it is dried at 50°C for 15 min to obtain a solid mixture.

[0068] (2) In a closed reactor filled with nitrogen at 350°C and an initial pressure of 3MPa, the solid mixture described in step (1) is pyrolyzed for 4 hours to obtain oil and gas products.

[0069] Wherein, the vitrinite reflectance of the shale powder in step (1) is 0.8%; the particle size of the shale powder in step (1) is <60 mesh; and the amount of solid ferrocene catalyst added in step (1) is 0.4% of the total mass of the shale powder.

[0070] Example 3

[0071] This embodiment provides a method for the pyrolysis of medium- and low-maturity shale oil and oil shale using ferrocene catalysis, the method comprising the following steps:

[0072] (1) First, the solid ferrocene catalyst and the anhydrous ethanol are ultrasonically mixed at a mass-to-volume ratio of 1:15 g / L to obtain a ferrocene catalyst solution. The ultrasonic power of the ultrasonic mixing is 200 W. Then, the ferrocene catalyst solution is added dropwise to the shale powder (shale powder in medium-low maturity shale oil) for impregnation. After that, it is dried at 60°C for 9 min to obtain a solid mixture.

[0073] (2) In a closed reactor filled with nitrogen at 480℃ and an initial pressure of 0.5MPa, the solid mixture described in step (1) was pyrolyzed for 4 hours to obtain oil and gas products.

[0074] Wherein, the vitrinite reflectance of the shale powder in step (1) is 1.1%; the particle size of the shale powder in step (1) is <60 mesh; and the amount of solid ferrocene catalyst added in step (1) is 0.5% of the total mass of the shale powder.

[0075] Example 4

[0076] This embodiment provides a method for pyrolysis of medium- and low-maturity shale oil and oil shale using ferrocene catalysis. Except for step (1), in which the amount of solid ferrocene catalyst added is 0.1% of the total mass of the shale powder, the method is the same as in Example 1.

[0077] Example 5

[0078] This embodiment provides a method for pyrolysis of medium- and low-maturity shale oil and oil shale using ferrocene catalysis. Except for step (1), in which the amount of solid ferrocene catalyst added is 0.5% of the total mass of the shale powder, the method is the same as in Example 1.

[0079] Example 6

[0080] This embodiment provides a method for pyrolysis of medium- and low-maturity shale oil and oil shale using ferrocene catalysis. Except for step (1), in which the amount of solid ferrocene catalyst added is 0.6% of the total mass of the shale powder, the method is the same as in Example 1.

[0081] Example 7

[0082] This embodiment provides a method for ferrocene-catalyzed pyrolysis of medium- and low-maturity shale oil and oil shale. Except for the drying temperature of 120°C in step (1), the method is the same as that in Example 1.

[0083] Example 8

[0084] This embodiment provides a method for ferrocene-catalyzed pyrolysis of medium- and low-maturity shale oil and oil shale. Except for the initial pressure of the pyrolysis reaction in step (2) being 0.5 MPa, the method is the same as that in Example 5.

[0085] Example 9

[0086] This embodiment provides a method for ferrocene-catalyzed pyrolysis of medium- and low-maturity shale oil and oil shale. Except for the initial pressure of the pyrolysis reaction in step (2) being 5 MPa, the method is the same as that in Example 5.

[0087] II. Comparative Example

[0088] Comparative Example 1

[0089] This comparative example provides a method for catalytic pyrolysis of medium- and low-maturity shale oil and oil shale. The method is the same as that in Example 1, except that the solid ferrocene catalyst in step (1) is replaced with the iron-based catalyst used in Example 1 of CN120054509A.

[0090] Comparative Example 2

[0091] This comparative example provides a method for pyrolyzing medium- and low-maturity shale oil and oil shale. The method is the same as in Example 1 except that step (1) is omitted and step (2) is performed directly on the shale powder.

[0092] III. Tests and Results

[0093] (i) After the pyrolysis reaction in the above embodiments or comparative examples is completed, the sealed reactor is cooled to room temperature (25°C), oil and gas products are collected, and the oil and gas recovery rates (shale oil recovery rate and shale gas recovery rate) are calculated. The results are shown in Table 1. A comparison chart of the oil and gas recovery rates and their improvement data obtained by the methods described in Examples 1, 4, 5, 8, 9 and Comparative Example 2 is plotted. The results are as follows: Figure 4 As shown,

[0094] Table 1

[0095]

[0096]

[0097] The data in Table 1 shows that:

[0098] (1) As can be seen from Examples 1 to 3, the ferrocene-catalyzed pyrolysis method for medium-low maturity shale oil and oil shale provided by the present invention promotes the pyrolysis of shale and significantly improves the oil and gas recovery rate, with the shale oil recovery rate reaching more than 0.41% and the shale gas recovery rate preferably reaching more than 7.72%.

[0099] (2) As can be seen from the combined examples 1 and 4 to 6, as the amount of solid ferrocene catalyst added in step (1) increases, the oil and gas recovery rate of the pyrolysis method gradually increases. When the amount of solid ferrocene catalyst added in step (1) increases to 0.6%, the oil and gas recovery rate no longer increases significantly. This indicates that the present invention further preferably adds the amount of solid ferrocene catalyst in step (1) to 0.3% to 0.5% of the total mass of the shale powder, which further improves the oil and gas recovery rate and ensures that the catalyst is not wasted, resulting in lower costs.

[0100] (3) It can be seen from the combined examples 1 and 7 that the drying temperature in step (1) of example 7 is too high, which leads to excessively high local temperature on the shale surface and sublimation of some ferrocene, resulting in a decrease in shale oil and gas recovery rate. This indicates that the present invention further prefers the drying temperature in step (1) to be 50-60°C, which further protects the ferrocene in the reaction system, so that the ferrocene can fully participate in the catalytic cracking of shale, thereby improving the yield of liquid shale oil.

[0101] (4) It can be seen from the combined examples 1, 8 and 9 that as the initial pressure of the pyrolysis reaction in step (2) increases, the oil and gas recovery rate gradually decreases. This indicates that the present invention further optimizes the initial pressure of the pyrolysis reaction in step (2) to be 0.5 to 3 MPa, which further improves the pyrolysis efficiency of shale and thus improves the oil and gas recovery rate.

[0102] (5) As can be seen from the comprehensive comparison of Example 1 with Comparative Examples 1 and 2, the iron-based catalyst used in Example 1 of CN120054509A in Comparative Example 1 has relatively poor diffusion and high temperature resistance, resulting in a decrease in shale oil recovery rate to 0.38% and shale gas recovery rate to 7.65%. Since no catalyst was used in Comparative Example 2, the shale powder was directly subjected to pyrolysis, resulting in extremely poor pyrolysis efficiency, with the shale oil recovery rate decreasing to 0.34% and the shale gas recovery rate decreasing to 7.31%. This shows that the present invention selects a solid ferrocene catalyst to catalyze the shale pyrolysis reaction, which significantly improves its pyrolysis efficiency.

[0103] pass Figure 4 The above conclusions were further verified, namely that the present invention selected a solid ferrocene catalyst to catalyze the shale pyrolysis reaction, which significantly improved its pyrolysis efficiency. Moreover, with the increase of the amount of solid ferrocene catalyst added in step (1), or with the decrease of the initial pressure of the pyrolysis reaction in step (2), the oil and gas recovery rate of the method gradually increased, and the oil and gas recovery enhancement rate also gradually increased.

[0104] (ii) After the pyrolysis reactions in Examples 1, 4, 5, and 9 above are completed, the sealed reactor is cooled to room temperature (25°C), the oil and gas products are collected, and the shale oil components are analyzed. The results are as follows: Figure 5 As shown, it can be seen that:

[0105] The shale oil obtained by the pyrolysis method of the present invention has a high gasoline and diesel content and a low heavy oil content, which can produce high-quality crude oil with good application value. Moreover, when the amount of solid ferrocene catalyst added in step (1) is 0.3% of the total mass of the shale powder (Example 1), the gasoline and diesel content of the obtained shale oil is relatively higher, and the heavy oil accounts for only 4.5%. When the initial pressure of the pyrolysis reaction in step (2) is 5 MPa (Example 9), the gasoline and diesel content of the obtained shale oil is as high as 72.8%, and the heavy oil content is even lower.

[0106] (iii) After the pyrolysis reactions in Examples 1, 4, 5, 9 and Comparative Example 2 are completed, the sealed reactor is cooled to room temperature (25°C), the oil and gas products are collected, and the shale gas components are analyzed. The results are as follows: Figure 6 As shown, it can be seen that:

[0107] Compared to the pyrolysis method in Comparative Example 2 without any catalyst, the pyrolysis method of this invention uses a solid ferrocene catalyst, which increases the levels of carbon dioxide, methane, dienes, and ethane / propane in the resulting shale gas. Furthermore, as the amount of solid ferrocene catalyst added increases, the levels of hydrogen, carbon dioxide, methane, dienes, and ethane / propane gradually rise, while C4 levels gradually decrease. This indicates that the addition of the solid ferrocene catalyst and the control of its amount in the method of this invention can promote the breaking of long-chain organic compounds and control the product distribution of low-carbon hydrocarbon organic matter in the produced oil at low temperatures. However, as the initial pressure of the pyrolysis reaction increases (Example 9), the levels of hydrogen, carbon dioxide, methane, dienes, ethane / propane, and C4 gradually decrease.

[0108] In summary, this invention selects a solid ferrocene catalyst to catalyze the pyrolysis reaction of medium- and low-maturity shale oil and oil shale, further selects the amount of the solid ferrocene catalyst added to be 0.3% to 0.5% of the total mass of the shale powder, and further optimizes the initial pressure of the pyrolysis reaction to be 0.5 MPa to 3 MPa. At the same time, it achieves a balance between high oil and gas production rate and high oil and gas quality, and fully converts and utilizes medium- and low-maturity shale oil and oil shale resources.

[0109] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for ferrocene-catalyzed pyrolysis of medium- and low-maturity shale oil and oil shale, characterized in that, The method includes the following steps: (1) Shale powder, solid ferrocene catalyst and solvent are mixed and dried to obtain a solid mixture; (2) After the solid mixture described in step (1) is subjected to a pyrolysis reaction, oil and gas products are obtained.

2. The method according to claim 1, characterized in that, The vitrinite reflectance of the shale powder in step (1) is 0.6-1.1%; Preferably, the particle size of the shale powder in step (1) is <60 mesh.

3. The method according to claim 1 or 2, characterized in that, The microstructure of the solid ferrocene catalyst in step (1) includes a combination of needle-like and rod-like structures; Preferably, the thermal decomposition temperature of the solid ferrocene catalyst in step (1) is 450–490 °C.

4. The method according to any one of claims 1 to 3, characterized in that, The solvent in step (1) includes a volatile solvent; Preferably, the volatile solvent includes any one or a combination of at least two of ethanol, dichloromethane, or water.

5. The method according to any one of claims 1 to 4, characterized in that, The amount of solid ferrocene catalyst added in step (1) is 0.1% to 1.0% of the total mass of the shale powder, preferably 0.3% to 0.5%; Preferably, the mass-to-volume ratio of the solid ferrocene catalyst to the solvent in step (1) is 1:(3-15)g / L.

6. The method according to any one of claims 1 to 5, characterized in that, The mixing in step (1) includes first mixing the solid ferrocene catalyst with the solvent to obtain a ferrocene catalyst solution, and then mixing the ferrocene catalyst solution with the shale powder. Preferably, the first mixing includes ultrasonic mixing; Preferably, the ultrasonic power of the ultrasonic mixture is 100-200W; Preferably, the second mixing includes impregnating the ferrocene catalyst solution by dripping it onto the shale powder.

7. The method according to any one of claims 1 to 6, characterized in that, The drying temperature in step (1) is ≤60℃, preferably 50~60℃; Preferably, the drying time in step (1) is 9 to 15 minutes.

8. The method according to any one of claims 1 to 7, characterized in that, The pyrolysis reaction described in step (2) is carried out in a closed environment filled with protective gas; Preferably, the protective gas includes nitrogen and / or argon.

9. The method according to any one of claims 1 to 8, characterized in that, The initial pressure of the pyrolysis reaction is 0.5–5 MPa, preferably 0.5–3 MPa; Preferably, the temperature of the pyrolysis reaction is 350–550°C; Preferably, the pyrolysis reaction takes 2 to 4 hours.

10. The method according to any one of claims 1 to 9, characterized in that, The method includes the following steps: (1) First, the solid ferrocene catalyst and the solvent are ultrasonically mixed at a mass-to-volume ratio of 1:(3-15) g / L to obtain a ferrocene catalyst solution. The ultrasonic power of the ultrasonic mixing is 1200W. Then, the ferrocene catalyst solution is added dropwise to the shale powder for impregnation. Then, dry at ≤60℃ for 9–15 min to obtain a solid mixture; (2) In a closed environment filled with protective gas at 350-550℃ and an initial pressure of 0.5-5MPa, the solid mixture in step (1) undergoes a pyrolysis reaction for 2-4 hours to obtain oil and gas products. Wherein, the vitrinite reflectance of the shale powder in step (1) is 0.6 to 1.1%; the particle size of the shale powder in step (1) is <60 mesh; and the amount of solid ferrocene catalyst added in step (1) is 0.1% to 1.0% of the total mass of the shale powder. The microstructure of the solid ferrocene catalyst in step (1) includes a combination of needle-like and rod-like structures; the thermal decomposition temperature of the solid ferrocene catalyst in step (1) is 450-490℃; the solvent in step (1) includes a volatile solvent; the volatile solvent includes any one or a combination of at least two of ethanol, dichloromethane or water.

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