An oil-in-water emulsion, a method for preparing the same, and use thereof

Abstract

The application provides an oil-in-water emulsion, a preparation method thereof and application thereof. The oil-in-water emulsion comprises an oil phase and an aqueous phase; the aqueous phase comprises an active metal component, an emulsifier and water; the active metal component comprises Fe salt and Zn salt; wherein the mass ratio of the water to the oil phase is 2-5:1; the mass percentage of the Fe salt in the oil-in-water emulsion is 1-8 wt%; and the molar ratio of Fe to Zn in the active metal component is 1-5:1. The oil-in-water emulsion is applied to the shale oil industry and has good pyrolysis efficiency and oil and gas yield.

Description

Technical Field

[0001] This invention relates to the field of in-situ catalytic pyrolysis technology for shale oil, and more specifically, to an oil-in-water emulsion, its preparation method, and its application. Background Technology

[0002] Oil shale, as an important unconventional energy source, boasts abundant reserves. The pyrolysis of oil shale can produce liquid shale oil, whose efficient development and utilization are of great significance. However, traditional pyrolysis technologies suffer from low kerogen conversion efficiency, poor shale oil quality (high viscosity, high sulfur and nitrogen content), and insufficient yield, severely restricting its industrial application. Therefore, catalytic pyrolysis technology has become a research hotspot. By introducing catalysts to lower the reaction activation energy and optimize the pyrolysis pathway, it significantly improves oil production and product distribution.

[0003] In oil shale pyrolysis catalysis, four types of catalysts are commonly used: natural minerals, metal compounds, molecular sieves, and supported catalysts. Catalytic pyrolysis studies show that different catalysts exhibit significantly different mechanisms for product regulation. Natural minerals, such as montmorillonite, can increase shale oil yield. Metal oxides can increase the aromatic content in shale oil, while metal salts promote the decomposition of organic matter in oil shale, increasing the reaction rate. The appropriate addition of molecular sieves can not only increase shale oil yield but also help reduce the content of sulfur and nitrogen compounds. To further improve the oil and gas yield of oil shale, more efficient pyrolysis catalysts need to be developed.

[0004] To address the issue of further improving oil and gas yield through catalytic pyrolysis of oil shale, CN118956441A discloses a method for the catalytic pyrolysis of small-particle oil shale. The specific steps include grinding small-particle oil shale to obtain oil shale powder, then uniformly coating the surface of the oil shale powder with a catalyst to obtain catalyst-containing oil shale; drying the obtained catalyst-containing oil shale at low temperature, followed by fluidized bed roasting, and finally dust removal and cooling of the pyrolysis products. This invention, by combining catalytic pyrolysis and suspension roasting technologies, improves the dispersion state of the oil shale powder, thereby enhancing the pyrolysis efficiency of organic matter in the oil shale.

[0005] CN114477317A discloses a method for preparing needle-shaped nano-iron-based bimetallic hydroxides, their application in the catalytic pyrolysis of oil shale, and the method for using this catalyst in the catalytic pyrolysis of oil shale. The catalyst's plates contain metal cations composed of Fe... 3+ and from Ni 2+ Mn 2+ With Co 2+ It is composed of a divalent metal cation selected from the middle, and its interlayer anion is composed of OH. - CO3 2- and OCN -Composition. This needle-shaped nanocatalyst possesses advantages such as abundant active sites, high temperature resistance, and structural stability. Its application in the catalytic pyrolysis of oil shale can lower the pyrolysis reaction temperature and facilitate the conversion of experimental oil shale pyrolysis products into low- and medium-carbon hydrocarbon organic matter.

[0006] However, the aforementioned oil shale pyrolysis catalysts are mainly solid catalysts. The diffusion limitations of solid catalysts restrict their application in oil shale catalysis. Therefore, further development of liquid catalysts with high efficiency in shale oil and gas production is an urgent problem to be solved. Summary of the Invention

[0007] To address the problems in the prior art, the present invention aims to provide an oil-in-water emulsion, its preparation method, and its applications. This oil-in-water emulsion, when applied in the shale oil industry, exhibits good pyrolysis efficiency and oil and gas yield.

[0008] According to a first aspect of the present invention, an oil-in-water emulsion is provided, comprising an oil phase and an aqueous phase; The aqueous phase comprises an active metal component, an emulsifier, and water; the active metal component comprises Fe salt and Zn salt. The oil phase includes C10-C16 alkanes; The mass ratio of water to oil phase is 2-5:1; preferably 3-4:1. The Fe salt accounts for 1-8 wt% of the mass of the oil-in-water emulsion, preferably 4-6 wt%; the molar ratio of Fe to Zn in the active metal component is 1-5:1, preferably 2-3:1.

[0009] When the oil-in-water emulsion of the present invention is used as a liquid catalyst for pyrolysis of shale oil, the synergistic effect of the active metals and the diffusion effect of the emulsion itself can achieve more complete contact between shale and active metals, thereby improving the oil and gas recovery rate of shale oil.

[0010] Shale oil and gas yield increases with the introduction of active metals. However, the amount of active metals introduced should not be excessive, otherwise it will cause emulsion stratification, leading to system instability.

[0011] In some preferred embodiments of the present invention, the Fe salt includes one or more of nitrates, ferric sulfate, and ferric chloride.

[0012] In some preferred embodiments of the present invention, the Zn salt comprises one or a combination of two or more of zinc nitrate, zinc sulfate, and zinc chloride. Preferably, the Zn salt comprises zinc nitrate, which, under the above-mentioned preferred conditions, is more conducive to improving the oil and gas recovery rate of shale oil.

[0013] In some preferred embodiments of the present invention, the emulsifier accounts for 20-50 wt% of the oil-in-water emulsion, preferably 30-40 wt%. In some preferred embodiments of the present invention, the mass of the oil-in-water emulsion is calculated by subtracting the mass of iron salts and zinc salts from the total mass of the emulsion.

[0014] In some preferred embodiments of the present invention, the emulsifier includes one or more of Tween 80, Tween 60, and Span 80.

[0015] In some preferred embodiments of the present invention, the oil phase comprises one or a combination of two of n-decane and n-hexadecane.

[0016] According to another aspect of the present invention, a method for preparing an oil-in-water emulsion is provided, comprising: Fe salt, Zn salt, emulsifier, and water are mixed to obtain an aqueous phase; then the aqueous phase and oil phase are mixed and stirred to obtain the oil-in-water emulsion.

[0017] In some preferred embodiments of the present invention, the stirring speed is 5000~10000 rpm.

[0018] Preferably, the stirring is carried out in a homogenizing emulsifier.

[0019] In some preferred embodiments of the present invention, the Fe salt, the Zn salt, and water are mixed to obtain a first mixture, and then the first mixture is mixed with the emulsifier and stirred for 5 to 10 minutes to obtain the aqueous phase; then, under stirring conditions, the oil phase is added to the aqueous phase at a feeding rate of 0.5 to 1 mL / min to obtain the oil-in-water emulsion.

[0020] According to another aspect of the present invention, an oil-in-water emulsion is provided for use in the catalytic pyrolysis reaction of shale oil, wherein the oil-in-water emulsion is used as a liquid catalyst.

[0021] In some preferred embodiments of the present invention, the shale satisfies one or more of the following conditions: total organic carbon (TOC) content of 12% to 20%, and maximum pyrolysis temperature T. max The temperature range is 400℃~500℃, the hydrocarbon production potential S≥65mg / g, and the hydrogen content index HI≥450.

[0022] In some preferred embodiments of the present invention, the particle size of the shale is ≤0.25mm.

[0023] In some preferred embodiments of the present invention, the mass ratio of the oil-in-water emulsion to the shale is 1:(20~10000).

[0024] In some preferred embodiments of the present invention, the pyrolysis reaction conditions include: controlling the temperature of the reactor at 250°C to 650°C using a heating mantle; introducing hydrogen gas at an initial pressure of 0.1 MPa to 5 MPa and maintaining the reaction pressure at 0.1 MPa to 15 MPa; and controlling the pyrolysis reaction time at 1 to 3 hours.

[0025] Compared to existing technologies, this invention solves the problem of insufficient contact area and low pyrolysis efficiency caused by diffusion limitations of solid catalysts during the catalytic pyrolysis of medium- and low-maturity shale oil and oil shale. The ZnFe bimetallic oil-in-water emulsion provided by this invention is a liquid catalyst that can penetrate deep into shale fissures and kerogen networks, significantly increasing the contact area with organic matter, thereby improving pyrolysis efficiency and oil and gas yield. Simultaneously, this emulsion exhibits high-temperature resistance and structural stability. This invention achieves catalyst loading through a one-step emulsification method, avoiding complex calcination or impregnation steps, and meeting the low-cost requirements of industrial shale oil production. Detailed Implementation

[0026] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0027] Example 1

[0028] This embodiment provides an oil-in-water emulsion, the preparation method of which includes the following steps: Weigh out 2.00g of ferric nitrate, 0.74g of zinc nitrate, and 25.21g of water according to the proportions. Mix the three together and stir magnetically for 5 minutes until the mixture is homogeneous. Weigh out 9.45g of surfactant Tween 80 and add it to the above mixed solution. Stir magnetically for 10 minutes until the mixture is homogeneous to obtain the aqueous phase. Weigh out 12.60 g of n-decane as the oil phase of the emulsion; Add the aqueous phase to the emulsifier, and add the oil phase at a feeding rate of 1 mL / min while continuously stirring at 10,000 rpm in the emulsifier to avoid local overload that could lead to phase separation. Stir at 10,000 rpm at room temperature until the system is uniformly mixed to obtain a homogeneous oil-in-water emulsion.

[0029] Ferric nitrate accounts for 4 wt% of the oil-in-water emulsion, the iron-zinc molar ratio is 2:1, the water-oil mass ratio is 2:1, and the emulsifier accounts for 20 wt% of the oil-in-water emulsion (based on the total emulsion mass minus the mass of iron and zinc salts).

[0030] Example 2

[0031] This embodiment provides an oil-in-water emulsion. The preparation method of the oil-in-water emulsion includes the following steps: Weigh out 2.00g of ferric nitrate, 0.74g of zinc nitrate, and 20.48g of water according to the proportions. Mix the three together and stir magnetically for 5 minutes until the mixture is homogeneous. Weigh out 16.54g of surfactant Tween 80 and add it to the above mixed solution. Stir magnetically for 10 minutes until the mixture is homogeneous to obtain the aqueous phase. Weigh out 10.24 g of n-decane as the oil phase of the emulsion; The oil phase was added at a feed rate of 1 mL / min under continuous stirring at 10,000 rpm in an emulsifier to avoid local overload that could lead to phase separation. The mixture was stirred at 10,000 rpm at room temperature until homogeneous, resulting in a uniform oil-in-water emulsion.

[0032] The oil-in-water emulsion contains 4 wt% ferric nitrate, has a 2:1 iron-zinc molar ratio, contains 35 wt% emulsifier, and has a water-to-oil mass ratio of 2:1.

[0033] Example 3

[0034] This embodiment provides an oil-in-water emulsion.

[0035] The preparation method of this oil-in-water emulsion includes the following steps: Weigh out 2.00g of ferric nitrate, 0.74g of zinc nitrate, and 15.75g of water according to the proportions. Mix the three together and stir magnetically for 5 minutes until the mixture is homogeneous. Weigh out 23.63g of surfactant Tween 80 and add it to the above mixed solution. Stir magnetically for 10 minutes until the mixture is homogeneous to obtain the aqueous phase. Weigh 7.88 g of n-decane as the oil phase of the emulsion; add the oil phase at a feed rate of 1 mL / min under continuous stirring at 10000 rpm in an emulsifier to avoid local overload leading to phase separation; stir at 10000 rpm at room temperature until the system is uniformly mixed. A homogeneous oil-in-water emulsion is obtained.

[0036] The oil-in-water emulsion contains 4 wt% ferric nitrate, has a 2:1 iron-zinc molar ratio, contains 50 wt% emulsifier, and has a water-to-oil mass ratio of 2:1.

[0037] Example 4

[0038] This embodiment provides an oil-in-water emulsion.

[0039] The preparation method of this oil-in-water emulsion includes the following steps: Weigh out 2.00g of ferric nitrate, 0.74g of zinc nitrate, and 23.89g of water according to the proportions. Mix the three together and stir magnetically for 5 minutes until the mixture is homogeneous. Weigh out 16.54g of surfactant Tween 80 and add it to the above mixed solution. Stir magnetically for 10 minutes until the mixture is homogeneous to obtain the aqueous phase. Weigh 6.83 g of n-decane as the oil phase of the emulsion; add the oil phase at a feed rate of 1 mL / min under continuous stirring at 10000 rpm in an emulsifier to avoid local overload causing phase separation; stir at 10000 rpm at room temperature until the system is uniformly mixed. A homogeneous oil-in-water emulsion is obtained.

[0040] The oil-in-water emulsion contains 4 wt% ferric nitrate, has a 2:1 molar ratio of iron to zinc, contains 35 wt% emulsifier, and has a water-to-oil ratio of 3.5:1.

[0041] Example 5

[0042] This embodiment provides an oil-in-water emulsion.

[0043] The preparation method of this oil-in-water emulsion includes the following steps: Weigh out 2.00g of ferric nitrate, 0.74g of zinc nitrate, and 25.60g of water according to the proportions. Mix the three together and stir magnetically for 5 minutes until the mixture is homogeneous. Weigh out 16.54g of surfactant Tween 80 and add it to the above mixed solution. Stir magnetically for 10 minutes until the mixture is homogeneous to obtain the aqueous phase. Weigh 5.12 g of n-decane as the oil phase of the emulsion; add the oil phase at a feed rate of 1 mL / min under continuous stirring at 10000 rpm in an emulsifier to avoid local overload causing phase separation; stir at 10000 rpm at room temperature until the system is uniformly mixed. A homogeneous oil-in-water emulsion is obtained.

[0044] The oil-in-water emulsion contains 4 wt% ferric nitrate, has a 2:1 molar ratio of iron to zinc, contains 35 wt% emulsifier, and has a water-to-oil ratio of 5:1.

[0045] Example 6

[0046] This embodiment provides an oil-in-water emulsion.

[0047] The preparation method of this oil-in-water emulsion includes the following steps: Weigh out 2.00g of ferric nitrate, 0.71g of zinc sulfate, and 23.91g of water according to the proportions. Mix the three together and stir magnetically for 5 minutes until the mixture is homogeneous. Weigh out 16.55g of surfactant Tween 60 and add it to the above mixed solution. Stir magnetically for 10 minutes until the mixture is homogeneous to obtain the aqueous phase. Weigh 6.83 g of n-decane as the oil phase of the emulsion; add the oil phase at a feed rate of 1 mL / min under continuous stirring at 10000 rpm in an emulsifier to avoid local overload causing phase separation; stir at 10000 rpm at room temperature until the system is uniformly mixed. A homogeneous oil-in-water emulsion is obtained.

[0048] The oil-in-water emulsion contains 4 wt% ferric nitrate, has a 2:1 molar ratio of iron to zinc, contains 35 wt% emulsifier, and has a water-to-oil ratio of 3.5:1.

[0049] Example 7

[0050] This embodiment provides an oil-in-water emulsion.

[0051] The preparation method of this oil-in-water emulsion includes the following steps: Weigh out 0.50g of ferric nitrate, 0.18g of zinc nitrate, and 24.93g of water according to the proportions. Mix the three together and stir magnetically for 5 minutes until the mixture is homogeneous. Weigh out 17.26g of surfactant Tween 80 and add it to the above mixed solution. Stir magnetically for 10 minutes until the mixture is homogeneous to obtain the aqueous phase. Weigh 7.12 g of n-decane as the oil phase of the emulsion; add the oil phase at a feed rate of 1 mL / min under continuous stirring at 10000 rpm in an emulsifier to avoid local overload causing phase separation; stir at 10000 rpm at room temperature until the system is uniformly mixed. A homogeneous oil-in-water emulsion is obtained.

[0052] The oil-in-water emulsion contains 1 wt% ferric nitrate, has a 2:1 iron-zinc molar ratio, contains 35 wt% emulsifier, and has a water-to-oil mass ratio of 3.5:1.

[0053] Example 8

[0054] This embodiment provides an oil-in-water emulsion.

[0055] The preparation method of this oil-in-water emulsion includes the following steps: Weigh out 4.00g of ferric nitrate, 1.47g of zinc nitrate, and 22.51g of water according to the proportions. Mix the three together and stir magnetically for 5 minutes until the mixture is homogeneous. Weigh out 15.58g of surfactant Tween 80 and add it to the above mixed solution. Stir magnetically for 10 minutes until the mixture is homogeneous to obtain the aqueous phase. Weigh 6.43 g of n-decane as the oil phase of the emulsion; add the oil phase at a feed rate of 1 mL / min under continuous stirring at 10000 rpm in an emulsifier to avoid local overload causing phase separation; stir at 10000 rpm at room temperature until the system is uniformly mixed. A homogeneous oil-in-water emulsion is obtained.

[0056] The oil-in-water emulsion contains 8 wt% ferric nitrate, has a 2:1 iron-zinc molar ratio, contains 35 wt% emulsifier, and has a water-to-oil mass ratio of 3.5:1.

[0057] Example 9

[0058] This embodiment provides an oil-in-water emulsion.

[0059] The preparation method of this oil-in-water emulsion includes the following steps: Weigh out 2.00g of ferric nitrate, 1.47g of zinc nitrate, and 23.52g of water according to the proportions. Mix the three together and stir magnetically for 5 minutes until the mixture is homogeneous. Weigh out 16.28g of surfactant Tween 80 and add it to the above mixed solution. Stir magnetically for 10 minutes until the mixture is homogeneous to obtain the aqueous phase. Weigh 6.72 g of n-decane as the oil phase of the emulsion; add the oil phase at a feed rate of 1 mL / min under continuous stirring at 10000 rpm in an emulsifier to avoid local overload causing phase separation; stir at 10000 rpm at room temperature until the system is uniformly mixed. A homogeneous oil-in-water emulsion is obtained.

[0060] The oil-in-water emulsion contains 4 wt% ferric nitrate, has a 1:1 iron-zinc molar ratio, contains 35 wt% emulsifier, and has a water-to-oil mass ratio of 3.5:1.

[0061] Example 10

[0062] This embodiment provides an oil-in-water emulsion.

[0063] The preparation method of this oil-in-water emulsion includes the following steps: Weigh out 2.00g of ferric nitrate, 0.29g of zinc nitrate, and 24.12g of water according to the proportions. Mix the three together and stir magnetically for 5 minutes until the mixture is homogeneous. Weigh out 16.70g of surfactant Tween 80 and add it to the above mixed solution. Stir magnetically for 10 minutes until the mixture is homogeneous to obtain the aqueous phase. Weigh 6.89 g of n-decane as the oil phase of the emulsion; add the oil phase at a feed rate of 1 mL / min under continuous stirring at 10000 rpm in an emulsifier to avoid local overload causing phase separation; stir at 10000 rpm at room temperature until the system is uniformly mixed. A homogeneous oil-in-water emulsion is obtained.

[0064] The oil-in-water emulsion contains 4 wt% ferric nitrate, has a 5:1 iron-zinc molar ratio, contains 35 wt% emulsifier, and has a water-to-oil mass ratio of 3.5:1.

[0065] Example 11

[0066] This embodiment provides an oil-in-water emulsion.

[0067] The preparation method of this oil-in-water emulsion includes the following steps: Weigh out 2.00g of ferric nitrate, 0.74g of zinc nitrate, and 33.08g of water according to the proportions. Mix the three together and stir magnetically for 5 minutes until the mixture is homogeneous. Weigh out 4.73g of surfactant Tween 80 and add it to the above mixed solution. Stir magnetically for 10 minutes until the mixture is homogeneous to obtain the aqueous phase. 9.45 g of n-decane was weighed as the oil phase of the emulsion. The oil phase was added at a feed rate of 1 mL / min under continuous stirring at 10,000 rpm in an emulsifier. The mixture was stirred at 10,000 rpm at room temperature, and the resulting oil-in-water emulsion showed stratification.

[0068] The oil-in-water emulsion contains 4 wt% ferric nitrate, has a 2:1 molar ratio of iron to zinc, contains 10 wt% emulsifier, and has a water-to-oil mass ratio of 3.5:1.

[0069] Example 12

[0070] This embodiment provides an oil-in-water emulsion.

[0071] The preparation method of this oil-in-water emulsion includes the following steps: Weigh out 2.00g of ferric nitrate, 0.74g of zinc nitrate, and 14.70g of water according to the proportions. Mix the three together and stir magnetically for 5 minutes until the mixture is homogeneous. Weigh out 28.36g of surfactant Tween 80 and add it to the above mixed solution. Stir magnetically for 10 minutes until the mixture is homogeneous to obtain the aqueous phase. Weigh 4.20 g of n-decane as the oil phase of the emulsion; add the oil phase at a feed rate of 1 mL / min under continuous stirring at 10000 rpm in an emulsifier. Stir at 10000 rpm at room temperature. The resulting oil-in-water emulsion will separate into layers.

[0072] The oil-in-water emulsion contains 4 wt% ferric nitrate, has a 2:1 iron-zinc molar ratio, contains 60 wt% emulsifier, and has a water-to-oil mass ratio of 3.5:1.

[0073] Example 13

[0074] This embodiment provides an oil-in-water emulsion.

[0075] The preparation method of this oil-in-water emulsion includes the following steps: Weigh out 2.00g of ferric nitrate, 0.74g of zinc nitrate, and 23.89g of water according to the proportions. Mix the three together and stir magnetically for 5 minutes until the mixture is homogeneous. Weigh out 16.54g of surfactant Tween 80 and add it to the above mixed solution. Stir magnetically for 10 minutes until the mixture is homogeneous to obtain the aqueous phase. 6.83 g of n-hexadecane was weighed as the oil phase of the emulsion. The oil phase was added at a feed rate of 1 mL / min under continuous stirring at 10,000 rpm in an emulsifier. The mixture was stirred at 10,000 rpm at room temperature, and the resulting oil-in-water emulsion showed stratification.

[0076] The oil-in-water emulsion contains 4 wt% ferric nitrate, has a 2:1 molar ratio of iron to zinc, contains 35 wt% emulsifier, and has a water-to-oil ratio of 3.5:1.

[0077] Comparative Example 1

[0078] This comparative example provides an oil-in-water emulsion.

[0079] The preparation method of this oil-in-water emulsion includes the following steps: Weigh out 2.00g of ferric nitrate and 24.27g of water according to the proportion, mix the three together, and stir magnetically for 5 minutes until the mixture is homogeneous; weigh out 16.80g of surfactant Tween 80, add surfactant Tween 80 to the above mixed solution, and stir magnetically for 10 minutes until the mixture is homogeneous to obtain the aqueous phase; Weigh 6.93 g of n-decane as the oil phase of the emulsion; add the oil phase at a feed rate of 1 mL / min under continuous stirring at 10000 rpm in an emulsifier to avoid local overload causing phase separation; stir at 10000 rpm at room temperature until the system is uniformly mixed. A homogeneous oil-in-water emulsion is obtained.

[0080] The ferric nitrate accounts for 4 wt% of the oil-in-water emulsion, the emulsifier accounts for 35 wt% of the oil-in-water emulsion, and the water-to-oil mass ratio is 3.5:1.

[0081] Comparative Example 2

[0082] This comparative example provides an oil-in-water emulsion.

[0083] The preparation method of this oil-in-water emulsion includes the following steps: Weigh out 0.74g of zinc nitrate and 24.90g of water according to the proportion, mix the three together, and stir magnetically for 5 minutes until the mixture is homogeneous; weigh out 17.24g of surfactant Tween 80, add surfactant Tween 80 to the above mixed solution, and stir magnetically for 10 minutes until the mixture is homogeneous to obtain the aqueous phase; Weigh 7.12 g of n-decane as the oil phase of the emulsion; add the oil phase at a feed rate of 1 mL / min under continuous stirring at 10000 rpm in an emulsifier to avoid local overload causing phase separation; stir at 10000 rpm at room temperature until the system is uniformly mixed. A homogeneous oil-in-water emulsion is obtained.

[0084] The zinc nitrate accounts for 1.5 wt% of the oil-in-water emulsion, the emulsifier accounts for 35 wt% of the oil-in-water emulsion, and the water-to-oil ratio is 3.5:1.

[0085] Application Example 1

[0086] This application example provides a catalytic pyrolysis method for shale oil, including: Step 1: After crushing and sieving the shale sample, impregnate the shale powder with the oil-in-water emulsion and mix thoroughly. Place the resulting mixture in a reaction vessel.

[0087] The shale has a total organic carbon (TOC) content of 15% and a maximum pyrolysis temperature of T. max The temperature is 450℃, the hydrocarbon production potential S is 65mg / g, and the hydrogen content index HI is 450.

[0088] The shale has a particle size of ≤0.25mm.

[0089] Step 2: Continuously inject hydrogen gas into the reactor to displace the air and maintain the initial pressure. Use a heating mantle to increase the temperature and pressure of the reactor and maintain a constant temperature and pressure to generate oil and gas.

[0090] To improve the pyrolysis effect of shale oil and further enhance the synergistic effect of hydrogen and catalyst, the initial pressure of hydrogen introduced is 3 MPa, and the reaction pressure is maintained at 10 MPa.

[0091] Meanwhile, the temperature of the reactor was controlled at 450℃, and the pyrolysis reaction time was controlled at 2 hours.

[0092] Step 3: After the reaction is complete, cool the reactor to room temperature and collect the shale pyrolysis oil and gas.

[0093] After implementing the above application examples, the pyrolysis oil recovery rate and pyrolysis gas recovery rate of the examples and comparative examples are shown in Table 1.

[0094] The pyrolysis oil recovery rate is calculated as follows: Pyrolysis oil recovery rate = Mass of collected oil / Total mass of shale. The pyrolysis gas recovery rate is calculated as follows: Pyrolysis gas recovery rate = [(Weight loss of shale - Mass of shale oil - Mass of water) / Total mass of shale] × 100%.

[0095] Table 1

[0096] As shown in Table 1, the FeZn bimetallic oil-in-water emulsifier and hydrogen-induced catalytic pyrolysis of shale oil of the present invention can improve the shale oil gas recovery rate.

[0097] Under the same conditions, using the oil-in-water emulsion and hydrogen-exposed conditions of the present invention, the oil and gas recovery rate of Example 4 increased by 24.51% compared with Comparative Example 1, and by 49.76% compared with Comparative Example 2. These results show that the present invention achieves more complete contact between shale and active metals through the synergistic effect of active metals in the emulsion and the diffusion effect of the emulsion itself, thereby improving the oil and gas recovery rate of shale oil.

[0098] Based on the oil and gas recovery results of Examples 1, 2 and 3, it can be seen that as the amount of emulsifier added increases, the oil and gas recovery rate of shale oil shows a trend of first increasing and then decreasing, but the overall change is not significant.

[0099] The results from Examples 2, 4, and 5 show that as the water-to-oil mass ratio increases, the shale oil and gas yield first increases and then decreases.

[0100] The results from Examples 4 and 6 show that introducing Zn species in the form of zinc nitrate results in a higher oil and gas recovery rate in the emulsion.

[0101] Based on the combined results of the oil and gas recovery rates of Examples 4, 7, and 8, it can be seen that the oil and gas recovery rate of shale oil first increases and then decreases with the increase of active metal addition.

[0102] Based on the combined results of oil and gas recovery rates from Examples 4, 9, and 10, it can be seen that as the Fe / Zn molar ratio increases, the oil and gas recovery rate of shale oil first increases and then decreases.

[0103] Based on the oil and gas recovery results of Examples 4, 11 and 12, it can be seen that as the amount of emulsifier added increases, the oil and gas recovery of shale oil shows a trend of first increasing and then decreasing. This is related to the effect of the amount of emulsifier added on the stability of the emulsion. Only within a suitable range of emulsifier addition can the emulsion exist stably.

[0104] Based on the combined results of Example 4 and Example 13, it can be seen that the replacement of the oil phase has little impact on the oil and gas recovery rate of shale oil.

Claims

1. An oil-in-water emulsion, wherein, Including oil phase and aqueous phase; The aqueous phase comprises an active metal component, an emulsifier, and water; the active metal component comprises Fe salt and Zn salt. The oil phase includes C10-C16 alkanes; The mass ratio of water to oil phase is 2~5:1; The Fe salt accounts for 1-8 wt% of the mass of the oil-in-water emulsion; the molar ratio of Fe to Zn in the active metal component is 1-5:

1.

2. The oil-in-water emulsion of claim 1, wherein, The Fe salt includes one or more of ferric nitrate, ferric sulfate, and ferric chloride.

3. The oil-in-water emulsion of claim 1, wherein, The Zn salt includes one or more of zinc nitrate, zinc sulfate, and zinc chloride.

4. The oil-in-water emulsion of claim 1, wherein, The emulsifier accounts for 20-50% of the mass percentage of the oil-in-water emulsion.

5. The oil-in-water emulsion of claim 1, wherein, The mass ratio of water to oil phase is 3~4:

1.

6. The oil-in-water emulsion of claim 1, wherein, The Fe salt accounts for 4-6 wt% of the mass of the oil-in-water emulsion.

7. The oil-in-water emulsion of claim 1, wherein, The molar ratio of Fe to Zn in the active metal component is 2~3:

1.

8. The oil-in-water emulsion of claim 4, wherein, The emulsifier accounts for 30-40 wt% of the oil-in-water emulsion.

9. The oil-in-water emulsion of claim 1, wherein, The emulsifier includes one or more of Tween 80, Tween 60, and Span 80.

10. The oil-in-water emulsion of claim 1, wherein, The oil phase includes one or a combination of two of n-decane and n-hexadecane.

11. A method of preparing an oil-in-water emulsion as claimed in any one of claims 1 to 10, wherein, include: Fe salt, Zn salt, emulsifier, and water are mixed to obtain an aqueous solution; Then the aqueous solution and the oil phase are mixed and stirred to obtain the oil-in-water emulsion.

12. The method of claim 11, wherein the oil-in-water emulsion is prepared by, The stirring speed is 5000~10000 rpm.

13. The method of claim 11, wherein the oil-in-water emulsion is prepared by, include: The Fe salt, the Zn salt, and water are mixed to obtain a first mixture. Then, the first mixture is mixed with the emulsifier and stirred for 5-10 minutes to obtain the aqueous solution. Then, under stirring conditions, the oil phase is added to the aqueous solution at a feeding rate of 0.5-1 mL / min to obtain the oil-in-water emulsion.

14. Use of an oil-in-water emulsion as a liquid catalyst in a catalytic thermal cracking reaction of shale oil, wherein, The oil-in-water emulsion is the oil-in-water emulsion according to any one of claims 1 to 6, or the oil-in-water emulsion is prepared by the method for preparing the oil-in-water emulsion according to any one of claims 7 to 9.

15. Use according to claim 14, wherein, The shale satisfies one or more than two combinations of the following conditions: total organic carbon content of 12% to 20%, maximum pyrolysis temperature T max of 400°C to 500°C, hydrocarbon production potential S ≥ 65 mg / g, and hydrogen index HI ≥ 450.

16. The use according to claim 14, wherein, The shale has a particle size of ≤0.25mm.

17. The use according to claim 14, wherein, The mass ratio of the oil-in-water emulsion to the shale is 1:(20~10000).

18. The use according to claim 14, wherein, The conditions for the pyrolysis reaction include: a temperature of 250℃ to 650℃, an initial pressure of 0.1MPa to 5MPa for the hydrogen gas, a sustained reaction pressure of 0.1MPa to 15MPa, and a pyrolysis reaction time of 1 to 3 hours.

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