Fatty acid salt catalyst as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of catalysts, and particularly relates to a fatty acid salt catalyst as well as a preparation method and application thereof. Comprising the following steps: 1) mixing waste oil with water, heating, standing for layering to remove a lower-layer solution, adding alkali liquor into an upper-layer solution, heating, standing for layering to obtain an intermediate product; and 2) adding the intermediate product obtained in the step 1), a metal inorganic salt solution and methanol into a reactor, heating, washing and drying to obtain the fatty acid salt catalyst. The catalyst shows high catalytic activity, good dispersion performance and high stability in the coal / heavy oil hydro-conversion process, and is easy to store. The raw materials are wide in source and low in cost, and have remarkable economic advantages. Meanwhile, the application of the catalyst also solves the problem of utilization of waste oil, not only reduces environmental pollution, but also can turn waste oil into wealth. In the hydro-conversion process, the waste oil can be converted into valuable oil products, and synergistic conversion and utilization of the waste oil are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of catalysts, and in particular relates to a fatty acid salt catalyst and a preparation method and application thereof. Background Art

[0002] At present, the energy security situation is very serious. Clean and efficient utilization of coal and heavy oil resources to convert them into oil products and chemicals is an effective means to make up for the shortage of oil resources, accelerate economic development and reduce environmental pollution, and is also an important guarantee for energy security. Coal / heavy oil hydroconversion technology is a technology developed based on coal direct liquefaction technology to process coal and heavy oil together. Its basis is single coal direct liquefaction technology and heavy oil hydrocracking technology. Catalyst is a key factor in achieving efficient conversion of coal / heavy oil and obtaining high oil yield. It can effectively reduce the severity of the reaction, improve the utilization rate of activated hydrogen and the quality of liquid products, improve product quality, increase the conversion rate of coal, and improve the economy of the liquefaction process. It is currently a hot research topic in coal / heavy oil hydroconversion technology.

[0003] The development of coal / heavy oil hydroconversion catalysts has mainly gone through two stages: non-uniform solid powder catalysts and uniformly dispersed catalysts. Among them, the uniformly dispersed catalysts include water-soluble dispersed catalysts and oil-soluble dispersed catalysts. Both catalysts exist in the form of metal particles and their sulfides in the reaction. Both catalysts exist in the form of metal particles and their sulfides in the reaction. The active metals are generally transition metals of groups IVB, VB, VIB, VIIB and VIIIB, and the most common ones are Fe, Ni, Co and Mo. Solid powder catalysts have obvious disadvantages. First, the tail oil contains a large number of solid particles, which are difficult to use and handle; second, they have low dispersion and short life. The dispersion process of water-soluble catalysts is complicated, the hydrogenation activity is low, and the coal conversion rate is low. Compared with water-soluble catalysts, oil-soluble catalysts have simple dispersion processes, high hydrogenation activity, and obvious coke inhibition. Therefore, the development of fatty acid salt catalysts that are easier to prepare, low-cost and easy to store has become a topic of widespread concern.

[0004] A Chinese patent with publication number CN113492008A discloses a composite oil-soluble catalyst for coal tar slurry bed hydrogenation process. The patent uses oil as raw material to obtain a composite oil-soluble catalyst containing at least two metals. The preparation method includes the following steps: (1) oil and alkali solution are charged into a reactor in proportion for saponification reaction, and boiled and refluxed for 0.5 to 2 hours under stirring; (2) metal inorganic salt and solvent are added, and a replacement reaction is carried out under stirring, and the reaction is carried out at a temperature of 65 to 95°C for 1 to 3 hours; (3) cooling and standing for stratification, separating the upper organic phase, and evaporating the solvent to obtain a composite oil-soluble catalyst. The catalyst prepared in the patent has good solubility and dispersion in coal tar, high catalytic activity, and high light oil yield, but the catalyst preparation method is complicated, the catalyst stability is poor, and it is not easy to store. A Chinese patent with publication number CN117797866A discloses a hydrogenation conversion catalyst and its preparation method and application. The patent is to dissolve a metal inorganic salt in water to form a solution, adjust the pH value of the solution to acidic with alkali solution, add waste oil, heat to 80-120°C under stirring and react for 0.5-3h; let stand for stratification, take the upper organic phase, add an extractant for washing, and then evaporate the solvent, and dry to obtain the catalyst. The oil-soluble catalyst prepared by this patent has high catalytic activity, low cost and good dispersibility in the coal / heavy inferior oil hydrogenation conversion process. However, the catalyst prepared by this patent has poor stability, is not easy to store, and needs to adjust the pH value to acidic, which is a relatively harsh condition.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The purpose of the present invention is to provide a fatty acid salt catalyst and a preparation method and application thereof, using waste oil with a wide range of sources and low cost as a raw material, and preparing the catalyst by a methanol enhancement method, wherein methanol can provide a "soft boost" of a solvent during the synthesis process, which helps the reaction between an organic ligand and a metal ion or cluster, and promotes the formation of a fatty acid salt catalyst. The catalyst is used in coal / heavy oil hydrogenation conversion, and has the advantages of high catalytic activity, low cost, high dispersibility, good stability, easy storage, and reduced process operation costs.

[0007] To achieve the above objectives, the present invention adopts the following specific technical solutions.

[0008] The present invention provides a method for preparing a fatty acid salt catalyst, comprising the following steps:

[0009] 1) Mixing waste oil with water, heating, standing and stratifying to remove the lower solution, adding alkali solution to the upper solution, heating, standing and stratifying to obtain an intermediate product;

[0010] 2) The intermediate product obtained in step 1) is added into a reactor together with a metal inorganic salt solution and methanol, and heated, washed and dried to obtain a fatty acid salt catalyst.

[0011] Preferably, the waste oil comprises plant waste oil and / or animal waste oil;

[0012] Preferably, the waste oil comprises waste cooking oil;

[0013] Preferably, the plant waste oil comprises unsaturated fatty acids, and the animal waste oil comprises saturated fatty acids;

[0014] Preferably, the plant waste oil comprises oleic acid and / or linoleic acid, and the animal waste oil comprises stearic acid and / or palmitic acid;

[0015] Preferably, the plant waste oil includes one or more of peanut oil, soybean oil, walnut oil, sunflower oil, sesame oil, rice bran oil, corn oil, jatropha oil, palm oil, tung oil, coconut oil, cottonseed oil, camellia oil, rapeseed oil, safflower seed oil and peony seed oil; the animal waste oil includes one or more of beef tallow, sheep fat, lard and chicken fat.

[0016] Preferably, the alkali solution comprises an aqueous sodium hydroxide solution and / or an aqueous potassium hydroxide solution.

[0017] Preferably, the metal in the metal inorganic salt includes one or more of Fe, Ni, Mo, Co and W;

[0018] Preferably, the metal inorganic salt includes one or more of nitrate, hydrochloride, molybdate and tungstate.

[0019] Preferably, in step 1), the mass ratio of the waste oil to water is 1:1-2; and the mass concentration of the alkali solution is 10-50wt.%.

[0020] Preferably, in step 1), the waste oil is mixed with water, reacted at 80-100° C. for 1-2 h, alkali solution is added to the upper solution, hydrolyzed at 80-100° C. for 0.2-1 h, and after standing for stratification, glycerol is removed by salting out.

[0021] Preferably, in step 2), the molar ratio of the intermediate product to the metal inorganic salt is 1:2-4.5; the mass ratio of the intermediate product to methanol is 1:7-8.

[0022] Preferably, in step 2), heating is stopped after reacting at 60-80° C. for 3-6 hours.

[0023] The invention provides a fatty acid salt catalyst which is prepared by the preparation method.

[0024] The present invention provides an application of a fatty acid salt catalyst in coal and / or heavy oil hydrogenation conversion. Specifically, the present invention provides a preparation method and application of a fatty acid salt catalyst for coal / heavy oil hydrogenation conversion, which belongs to the technical field of catalysts. The preparation method firstly mixes waste oil and water in a certain mass ratio, reacts in a constant temperature water bath at 90°C for 1-2h, and after standing and stratifying to remove the lower layer solution, adds an alkali solution with a mass concentration of 30wt.% to the upper layer solution, and hydrolyzes at a constant temperature for 0.2-1h at 90°C. After standing and stratifying, washes with a NaCl solution to remove glycerol to obtain a light yellow solid intermediate product. Then, the light yellow solid intermediate product, a metal inorganic salt solution and methanol are sequentially added to a reactor in a certain mass ratio, and the heating is stopped after stirring the reaction at 70°C for 3-6h. The obtained dark yellow agglomerate is collected and washed with water to form a brown rubber-like solid, and dried after homogeneous dispersion to obtain a reddish brown powder, which is the fatty acid salt catalyst.

[0025] Compared with the prior art, the advantages of the present invention are:

[0026] The raw material source of the catalyst in the present invention is wide and the cost is low; at the same time, the application of the catalyst also solves the problem of waste oil utilization, not only reduces environmental pollution, but also can realize the transformation of waste oil into treasure. In the hydrogenation conversion process, the waste oil itself can be converted into valuable oil products, realizing the coordinated conversion and utilization of waste oil.

[0027] The catalyst of the present invention is prepared by a methanol enhancement method, and is a solid powder catalyst, which has good solubility and dispersion in coal / heavy oil, high intrinsic activity, high stability, and is easy to store. In addition, the pH of the solution does not need to be adjusted during the preparation process. During the coal / heavy oil hydrogenation reaction, the conversion of the coal / heavy oil can be further promoted, and the coal conversion rate and oil yield can be improved. DETAILED DESCRIPTION

[0028] The embodiments of the present invention will be described in detail below in conjunction with specific examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. In the examples, if specific conditions are not specified, the conditions are carried out according to normal conditions or manufacturer recommendations. If the reagents or instruments used do not specify the manufacturer, they are all conventional products that can be purchased commercially. In addition, the unspecified component ratios or contents in the present invention can all be any ratios or contents, and are not limited to the relationships such as mass ratio, concentration ratio, molar ratio or volume ratio.

[0029] Usually, the effective products converted from coal / heavy oil to oil products mainly refer to n-hexane solubles. Therefore, in the examples, the test results are calculated based on the yield of n-hexane solubles.

[0030] Example 1

[0031] A method for preparing a fatty acid Ni / Mo composite catalyst comprises the following steps: mixing 100g of kitchen waste peanut oil with 120g of deionized water, placing the mixture in a constant temperature water bath at 90°C for 1.5h, allowing the mixture to stand for stratification to remove a lower layer solution, adding an alkali solution with a mass concentration of 30wt.% to an upper layer solution, performing constant temperature hydrolysis at 90°C for 0.5h, allowing the mixture to stand for stratification, washing with a NaCl solution to remove glycerol, obtaining sodium fatty acid, and then subjecting the sodium fatty acid, 145.57g of a nickel nitrate solution (1.64mol / L), 106.7g of an ammonium molybdate solution (1.53mol / L) and 750mL of methanol to a methanol-enhanced reaction, reacting the mixture under stirring at 70°C for 4h, filtering the mixture, and drying the mixture in a vacuum drying oven at 75°C for 24h to obtain the fatty acid Ni / Mo composite catalyst, wherein the molar ratio of Ni to Mo is 1:1.

[0032] The Shangwan coal sample (dry ash-free basis), the prepared fatty acid Ni / Mo composite catalyst, sulfur and tetralin were mixed and added into a 100mL high-pressure reactor. Among them, the mass ratio of the Shangwan coal sample to tetralin was 1:2; the molar ratio of sulfur to Ni+Mo was 2:1; the amount of fatty acid Ni / Mo composite catalyst (based on the mass of active metal Ni+Mo) added was 1wt.% of the Shangwan coal sample. After replacing with 3MPa nitrogen for 3 times and then with 3MPa hydrogen for 3 times, hydrogen was filled to make the pressure reach 7MPa, and the temperature was raised from room temperature to 450℃ at a heating rate of 10℃ / min. After keeping the temperature constant for 1h, the temperature was rapidly cooled with a blower. The results showed that the yield of n-hexane soluble matter was 72wt.%.

[0033] Tahe residual oil, the prepared fatty acid Ni / Mo composite catalyst, sulfur and tetralin were mixed and added into a 100mL high-pressure reactor. Among them, the mass ratio of Tahe residual oil and tetralin was 1:2; the molar ratio of sulfur to Ni+Mo was 2:1; the amount of fatty acid Ni / Mo composite catalyst (based on the mass of active metal Ni+Mo) added was 1wt% of Tahe residual oil. After replacing with 3MPa nitrogen for 3 times and then with 3MPa hydrogen for 3 times, hydrogen was filled to make the pressure reach 7MPa, and the temperature was raised from room temperature to 450℃ at a heating rate of 10℃ / min. After keeping the temperature constant for 1h, the temperature was rapidly cooled with a blower. The results showed that the yield of n-hexane soluble matter was 88wt.%.

[0034] The Shangwan coal sample (dry ash-free basis), the prepared fatty acid Ni / Mo composite catalyst, sulfur, Tahe residual oil and tetralin were mixed and added into a 100mL high-pressure reactor. Among them, the mass ratio of the Shangwan coal sample, tetralin and Tahe residual oil was 1:1:1; the molar ratio of sulfur to Ni+Mo was 2:1; the amount of fatty acid Ni / Mo composite catalyst (based on the mass of active metal Ni+Mo) added was 1wt.% of the total of the Shangwan coal sample and Tahe residual oil. After replacing with 3MPa nitrogen for 3 times and then with 3MPa hydrogen for 3 times, hydrogen was filled to make the pressure reach 7MPa, and the temperature was raised from room temperature to 450℃ at a heating rate of 10℃ / min. After being kept constant for 1h, the temperature was rapidly cooled with a blower. The results showed that the yield of n-hexane soluble matter was 69wt.%.

[0035] Example 2

[0036] A preparation method of a fatty acid Fe / Ni / Mo composite catalyst comprises the following steps: mixing 100g of kitchen waste soybean oil with 150g of deionized water, placing the mixture in a constant temperature water bath at 90°C for 1h, allowing the mixture to stand for stratification and removing a lower layer solution, adding an alkali solution with a mass concentration of 20wt.% to an upper layer solution, and subjecting the mixture to constant temperature hydrolysis at 95°C for 0.2h, allowing the mixture to stand for stratification, and washing the mixture with a NaCl solution to remove glycerol to obtain fatty acid sodium, and then subjecting the obtained fatty acid sodium, 105.93g of nickel nitrate solution (1.64mol / L), 71.40g of ammonium molybdate solution (1.53mol / L), 59.3g of ferric chloride solution (1.85mol / L) and 750mL of methanol to a methanol enhanced reaction, reacting the mixture under stirring at 70°C for 3h, filtering the mixture, and drying the mixture in a vacuum drying oven at 75°C for 24h to obtain a fatty acid Fe / Ni / Mo composite catalyst, wherein the molar ratio of Fe, Ni and Mo is 1:1:1.

[0037] The Shangwan coal sample (dry ash-free basis), the prepared fatty acid Fe / Ni / Mo composite catalyst, sulfur and tetralin were mixed and added into a 100mL high-pressure reactor. Among them, the mass ratio of the Shangwan coal sample to tetralin was 1:2; the molar ratio of sulfur to Fe+Ni+Mo was 2:1; the amount of fatty acid Fe / Ni / Mo composite catalyst (based on the mass of active metal Fe+Ni+Mo) added was 1wt.% of the Shangwan coal sample. After replacing with 3MPa nitrogen for 3 times and then with 3MPa hydrogen for 3 times, hydrogen was filled to make the pressure reach 7MPa, and the temperature was raised from room temperature to 450℃ at a heating rate of 10℃ / min. After keeping the temperature constant for 1h, the temperature was rapidly cooled with a blower. The results showed that the yield of n-hexane soluble matter was 72wt.%.

[0038] Example 3

[0039] A preparation method of a fatty acid Fe / Mo composite catalyst comprises the following steps: mixing 100g of kitchen waste sunflower oil with 100g of deionized water, placing the mixture in a constant temperature water bath at 100°C for 2h, allowing the mixture to stand for stratification to remove a lower layer solution, adding an alkali solution with a mass concentration of 45wt.% to an upper layer solution, and subjecting the mixture to constant temperature hydrolysis at 95°C for 1h. After allowing the mixture to stand for stratification, glycerol is washed out with a NaCl solution to obtain fatty acid sodium, and then subjecting the obtained fatty acid sodium, 107.1g of ammonium molybdate solution (1.53mol / L), 88.93g of ferric chloride solution (1.85mol / L) and 750mL of methanol to a methanol-enhanced reaction, reacting the mixture under stirring at 65°C for 4h, filtering the mixture, and drying the mixture in a vacuum drying oven at 75°C for 24h to obtain a fatty acid Ni / Mo composite catalyst, wherein the molar ratio of Ni to Mo is 1:1.

[0040] The Shangwan coal sample (dry ash-free basis), the prepared fatty acid Fe / Mo composite catalyst, sulfur and tetralin were mixed and added into a 100mL high-pressure reactor. Among them, the mass ratio of the Shangwan coal sample to tetralin was 1:2; the molar ratio of sulfur to Fe+Mo was 2:1; the amount of fatty acid Fe / Mo composite catalyst (based on the mass of active metal Fe+Mo) added was 1wt.% of the Shangwan coal sample. After replacing with 3MPa nitrogen for 3 times and then with 3MPa hydrogen for 3 times, hydrogen was filled to make the pressure reach 7MPa, and the temperature was raised from room temperature to 450℃ at a heating rate of 10℃ / min. After keeping the temperature constant for 1h, the temperature was rapidly cooled with a blower. The results showed that the yield of n-hexane soluble matter was 71wt.%.

[0041] Example 4

[0042] A preparation method of a fatty acid Fe / Ni composite catalyst comprises the following steps: mixing 100g of kitchen waste sesame oil with 150g of deionized water, placing the mixture in a constant temperature water bath at 80°C for 1h, allowing the mixture to stand for stratification and removing a lower layer solution, adding an alkali solution with a mass concentration of 15wt.% to an upper layer solution, and performing constant temperature hydrolysis at 85°C for 0.2h. After allowing the mixture to stand for stratification, washing with a NaCl solution to remove glycerol to obtain fatty acid sodium, and then subjecting the obtained fatty acid sodium, 158.9g of a nickel nitrate solution (1.64mol / L), 88.97g of a ferric chloride solution (1.85mol / L) and 750mL of methanol to a methanol enhanced reaction, reacting the mixture under stirring at 60°C for 3h, filtering the mixture, and drying the mixture in a vacuum drying oven at 75°C for 24h to obtain a fatty acid Fe / Ni composite catalyst, wherein the molar ratio of Fe to Ni is 1:1.

[0043] The fatty acid Fe / Ni composite catalyst, sulfur and tetralin prepared from the Shangwan coal sample (dry ash-free basis) were mixed and added to a 100mL high-pressure reactor. Among them, the mass ratio of the Shangwan coal sample to tetralin was 1:2; the molar ratio of sulfur to Fe+Ni was 2:1; the amount of fatty acid Fe / Ni composite catalyst (based on the mass of active metal Fe+Ni) added was 1wt.% of the Shangwan coal sample. After replacing with 3MPa nitrogen for 3 times and then with 3MPa hydrogen for 3 times, hydrogen was filled to make the pressure reach 7MPa, and the temperature was raised from room temperature to 450℃ at a heating rate of 10℃ / min. After keeping the temperature constant for 1h, the temperature was rapidly cooled with a blower. The results showed that the yield of n-hexane soluble matter was 69wt.%.

[0044] Example 5

[0045] A preparation method of a fatty acid Fe / Co composite catalyst comprises the following steps: mixing 100g of kitchen waste safflower seed oil with 150g of deionized water, placing the mixture in a constant temperature water bath at 90°C for 1h, allowing the mixture to stand for stratification and removing a lower layer solution, adding an alkali solution with a mass concentration of 50wt.% to an upper layer solution, and hydrolyzing the mixture at a constant temperature at 100°C for 0.2h. After allowing the mixture to stand for stratification, washing the mixture with a NaCl solution to remove glycerol to obtain sodium fatty acid, and then subjecting the obtained sodium fatty acid, 99.97g of a cobalt nitrate solution (1.64mol / L), 88.93g of a ferric chloride solution (1.85mol / L) and 750mL of methanol to a methanol-enhanced reaction, reacting the mixture under stirring at 80°C for 3h, filtering the mixture, and drying the mixture in a vacuum drying oven at 75°C for 24h to obtain a fatty acid Fe / Co composite catalyst, wherein the molar ratio of Fe to Co is 1:1.

[0046] The Shangwan coal sample (dry ash-free basis), the prepared fatty acid Fe / Co composite catalyst, sulfur and tetralin were mixed and added into a 100mL high-pressure reactor. Among them, the mass ratio of the Shangwan coal sample to tetralin was 1:2; the molar ratio of sulfur to Fe+Co was 2:1; the amount of fatty acid Fe / Co composite catalyst (based on the mass of active metal Fe+Co) added was 1wt.% of the Shangwan coal sample. After replacing with 3MPa nitrogen for 3 times and then with 3MPa hydrogen for 3 times, hydrogen was filled to make the pressure reach 7MPa, and the temperature was raised from room temperature to 450℃ at a heating rate of 10℃ / min. After keeping the temperature constant for 1h, the temperature was rapidly cooled with a blower. The results showed that the yield of n-hexane soluble matter was 68wt.%.

[0047] Example 6

[0048] A preparation method of a fatty acid Fe catalyst comprises the following steps: mixing 100 g of kitchen waste safflower seed oil with 120 g of deionized water, placing the mixture in a constant temperature water bath at 95° C. for 1.5 h, allowing the mixture to stand for stratification and removing the lower layer solution, adding an alkali solution with a mass concentration of 35 wt.% to the upper layer solution, and hydrolyzing the mixture at a constant temperature at 90° C. for 0.5 h. After allowing the mixture to stand for stratification, washing with a NaCl solution to remove glycerol to obtain sodium fatty acid, and then subjecting the obtained sodium fatty acid, 177.9 g of ferric chloride solution (1.85 mol / L) and 750 mL of methanol to a methanol-enhanced reaction, reacting the mixture under stirring at 75° C. for 4 h, filtering the mixture, and drying the mixture in a vacuum drying oven at 75° C. for 24 h to obtain a fatty acid Fe catalyst.

[0049] The Shangwan coal sample (dry ash-free basis), the prepared fatty acid Fe catalyst, sulfur and tetralin were mixed and added into a 100mL high-pressure reactor. Among them, the mass ratio of the Shangwan coal sample and tetralin was 1:2; the molar ratio of sulfur to Fe was 2:1; the amount of fatty acid Fe catalyst (based on the mass of active metal Fe) added was 1wt.% of the Shangwan coal sample. After replacing with 3MPa nitrogen for 3 times and then with 3MPa hydrogen for 3 times, hydrogen was filled to make the pressure reach 7MPa, and the temperature was raised from room temperature to 450℃ at a heating rate of 10℃ / min. After keeping the temperature constant for 1h, the temperature was rapidly cooled with a blower. The results showed that the yield of n-hexane soluble matter was 64wt.%.

[0050] Comparative Example 1

[0051] The Shangwan coal sample (dry ash-free basis), Shenhua ultrafine hydrated iron oxide (FeOOH) catalyst, sulfur and tetralin were mixed and added into a 100mL high-pressure reactor. Among them, the mass ratio of the Shangwan coal sample to tetralin was 1:2; the molar ratio of sulfur to Fe was 2:1; the amount of FeOOH catalyst (based on the mass of active metal Fe) added was 1wt.% of the Shangwan coal sample. After replacing with 3MPa nitrogen for 3 times and then with 3MPa hydrogen for 3 times, hydrogen was filled to make the pressure reach 7MPa, and the temperature was raised from room temperature to 450℃ at a heating rate of 10℃ / min. After being kept constant for 1h, the temperature was rapidly cooled with a blower. The results showed that the yield of n-hexane soluble matter was 58wt.%.

[0052] Comparative Example 2

[0053] The Shangwan coal sample (dry ash-free basis), the iron trioxide catalyst of Tianjin Beilian Fine Chemicals Development Co., Ltd., sulfur and tetralin were mixed and added into a 100mL high-pressure reactor. Among them, the mass ratio of the Shangwan coal sample and tetralin was 1:2; the molar ratio of sulfur to Fe was 2:1; the amount of the iron trioxide catalyst (based on the mass of active metal Fe) added was 1wt.% of the Shangwan coal sample. After replacing with 3MPa nitrogen for 3 times and then with 3MPa hydrogen for 3 times, hydrogen was filled to make the pressure reach 7MPa, and the temperature was raised from room temperature to 450℃ at a heating rate of 10℃ / min. After keeping the temperature constant for 1h, the temperature was rapidly cooled with a blower. The results showed that the yield of n-hexane soluble matter was 57wt.%.

[0054] It can be seen that the catalytic effect of the catalyst of the present invention is greatly improved compared with the currently commercially available catalysts.

[0055] The catalyst of the present invention exhibits high catalytic activity, good dispersibility and high stability in the coal / heavy oil hydroconversion process, and is easy to store. It has a wide range of raw material sources, low cost, and significant economic advantages. At the same time, the application of the catalyst also solves the problem of waste oil utilization, not only reduces environmental pollution, but also can realize the transformation of waste oil into treasure, for example, restaurant waste oil. In the hydroconversion process, the waste oil itself can be converted into valuable oil products, realizing the coordinated conversion and utilization of waste oil.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

[0057] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and to form different embodiments. For example, in the above claims, any one of the claimed embodiments may be used in any combination. The information disclosed in this background technology section is intended only to deepen the understanding of the overall background technology of the present invention and should not be regarded as an admission or in any form of implication that the information constitutes prior art known to those skilled in the art.

Claims

1. A method for preparing a fatty acid salt catalyst comprises the following steps: 1) Mixing waste oil with water, heating, standing and stratifying to remove the lower solution, adding alkali solution to the upper solution, heating, standing and stratifying to obtain an intermediate product; 2) The intermediate product obtained in step 1) is added into a reactor together with a metal inorganic salt solution and methanol, and heated, washed and dried to obtain a fatty acid salt catalyst.

2. The preparation method according to claim 1, characterized in that: The waste oil includes plant waste oil and / or animal waste oil; Preferably, the waste oil comprises waste cooking oil; Preferably, the plant waste oil comprises unsaturated fatty acids, and the animal waste oil comprises saturated fatty acids; Preferably, the plant waste oil comprises oleic acid and / or linoleic acid, and the animal waste oil comprises stearic acid and / or palmitic acid; Preferably, the plant waste oil includes one or more of peanut oil, soybean oil, walnut oil, sunflower oil, sesame oil, rice bran oil, corn oil, jatropha oil, palm oil, tung oil, coconut oil, cottonseed oil, camellia oil, rapeseed oil, safflower seed oil and peony seed oil; the animal waste oil includes one or more of beef tallow, sheep fat, lard and chicken fat.

3. The preparation method according to claim 1, characterized in that: The alkali solution includes a sodium hydroxide aqueous solution and / or a potassium hydroxide aqueous solution.

4. The preparation method according to claim 1, characterized in that: The metal in the metal inorganic salt includes one or more of Fe, Ni, Mo, Co and W; Preferably, the metal inorganic salt includes one or more of nitrate, hydrochloride, molybdate and tungstate.

5. The preparation method according to claim 1, characterized in that: In step 1), the mass ratio of the waste oil to water is 1:1-2; the mass concentration of the alkali solution is 10-50wt.%.

6. The preparation method according to claim 1, characterized in that: In step 1), the waste oil is mixed with water, reacted at 80-100° C. for 1-2 hours, alkali solution is added to the upper solution, hydrolyzed at 80-100° C. for 0.2-1 hour, and after standing for stratification, glycerol is removed by salting out.

7. The preparation method according to claim 1, characterized in that: In step 2), the molar ratio of the intermediate product to the metal inorganic salt is 1:2-4.5; the mass ratio of the intermediate product to methanol is 1:7-8.

8. The preparation method according to claim 1, characterized in that: In step 2), the heating is stopped after reacting at 60-80°C for 3-6 hours.

9. A fatty acid salt catalyst, characterized in that Prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the fatty acid salt catalyst according to claim 9 in coal and / or heavy oil hydrogenation conversion.