Porous liquid catalyst, preparation method thereof and application of porous liquid catalyst in hydrogenation tackifying of coal

Abstract

The invention provides a porous liquid catalyst, a preparation method thereof and application of the porous liquid catalyst in hydrogenation tackifying of coal, and belongs to the technical field of liquid catalysts. The method comprises the following steps: dissolving zinc nitrate and dimethylimidazole in methanol, carrying out ultrasonic mixing and heating, separating the precipitate, adding into [Bpy] [Ntf2], and stirring until the solution is a uniform white solution, thereby obtaining the porous liquid catalyst. The method is mild in reaction condition and simple and convenient to operate, and the prepared catalyst is stable in performance, non-volatile, high in hydrogenation activity, high in tackifying and desulfurizing efficiency, suitable for large-scale production and wide in application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of liquid catalysts, in particular to a porous liquid catalyst, a preparation method thereof and application thereof in hydrogenation and tackification of coal. BACKGROUND

[0002] Coke, as an irreplaceable basic raw material in blast furnace ironmaking, is both a fuel and a reducing agent and a structural support agent, known as "the wooden material of blast furnace". High-strength metallurgical coke needs high-quality main coking coal (high basicity coking coal), but such coal resources are scarce, unevenly distributed and high in price. With the urgent shortage of high-quality coking coal resources and the continuous increase in demand for high-strength metallurgical coke in the steel industry, how to improve the loss of low-tack coal, improve the quality of coke and reduce energy consumption and environmental pollution in the production process has become the key background for the development of coking technology. Researchers have proposed that low-tack coal of different metamorphic degrees can be slightly hydrogenated at lower temperatures and pressures, so that some properties (such as plasticity, tar yield and volatile matter, etc.) tend to be medium metamorphic fat coal. At present, this theory has been further confirmed and applied. Huang et al. used anthracene oil as a solvent to modify Yulin coal at 350℃ and 4MPa, and obtained modified coal with GRI of 70 (IOP Conference Series Materials Science and Engineering 2017, 275(1): 012020.); Liu et al. further hydrogenated and modified Shenfu coal with tetralin-glycerol as the solvent system and FeOOH-S as the catalyst, and obtained modified coal with GRI of 80 (Asia-Pacific Journal of Chemical Engineering, 2019, 14(5)).

[0003] The hydrogenation and tackification catalysts in the above technical solutions are mostly iron-based solid-phase catalysts in the coal liquefaction process. However, the direct addition of solid-phase catalysts is very unfavorable for the dispersion and contact of the entire reaction system, and the addition of sulfur-containing auxiliary substances will increase the sulfur content in the product, and the catalyst cannot be separated from the solid-phase product in the later stage, resulting in an increase in ash content and a decrease in coking strength in the later stage of coal blending.

[0004] Porous liquids (PLs) are green solvents and functional materials that have attracted widespread attention in recent years. They have the advantages of easy separation, easy recovery, recyclability, and no pollution. Porous liquid catalysts are widely used in catalytic conversion (Chinese Journal of Structural Chemistry 2023, 42, 4, 100045). For example, Zhang et al. used PLs as catalysts to catalyze the reaction between propylene oxide (PO) and CO2 (ACS Appl. Mater. Interfaces 2024, 16, 45, 61957-61969). Chinese patent CN202411116723.8 discloses a biomass-based porous liquid catalyst, application and method for preparing cyclic carbonate substances. Compared with other synthesis methods, the catalyst provided by the present application has the advantages of high efficiency, mild reaction conditions, and simple catalytic system, making the yield of cyclic carbonates reach about 97%. Chinese patent CN202510460781.0 discloses a MIL-100(Fe)-based porous liquid material and its preparation and application method in extraction-coupled oxidative desulfurization. The material can achieve efficient adsorption of sulfide molecules and oxidative desulfurization reaction under a wider range of operating conditions. Compared with traditional solid MOF materials, the material has significant advantages in desulfurization process, including higher desulfurization rate (more than 90%), faster reaction speed and excellent cycle stability. However, there is no public report on the application of metal-organic framework-ILs composite porous liquid catalysts to the coal hydrogenation and tackification process.

[0005] Therefore, how to prepare a porous liquid catalyst and apply it to the coal hydrogenation and tackification process has become a problem that needs to be solved by those skilled in the art. SUMMARY

[0006] The purpose of the present application is to provide a porous liquid catalyst, its preparation method and application in coal hydrogenation and tackification, to solve the above technical problems.

[0007] In order to achieve the above-mentioned purpose of the application, the present application provides the following technical solutions: The present application provides a preparation method of a porous liquid catalyst, comprising the following steps: Zinc nitrate and dimethylimidazole are dissolved in a solvent and ultrasonically mixed and heated. After separating the precipitate, centrifugal separation, drying are sequentially performed. Then the obtained solid is dispersed in [Bpy][Ntf2] to obtain a white solution, which is the porous liquid catalyst. The molar ratio of zinc nitrate to dimethylimidazole is 1:1.8-2.2.

[0008] Further, the [Bpy][Ntf2] is nitrogen-butyl pyridine triflate, and the zinc nitrate is zinc nitrate hexahydrate.

[0009] Further, the molar ratio of the zinc nitrate to the solvent is 0.00288-0.00488:1.25, and the solvent comprises methanol.

[0010] Further, the power of the ultrasonic is 80-100 W, and the time is 3-8 min; the heating temperature is 45-55 DEG C, and the time is 3.5-4.5 h.

[0011] Further, the mass ratio of the solid to the [Bpy][Ntf2] is 1:15-20.

[0012] The application further provides the porous liquid catalyst prepared by the preparation method.

[0013] The application further provides an application of the porous liquid catalyst in coal hydrogenation and tackification, which comprises the following steps: The porous liquid catalyst is reacted with coal under a hydrogen atmosphere, and the reaction product is sequentially subjected to solid-liquid separation and drying, so as to obtain a solid product. The mass ratio of the coal to the porous liquid catalyst is 120-160:1.

[0014] Further, the reaction temperature is 350-390 DEG C, the reaction time is 50-70 min, and the reaction pressure is 1-3 MPa.

[0015] Further, the heating rate for rising to the reaction temperature is 3-7 DEG C / min; the drying is vacuum drying, the temperature is 100-110 DEG C, and the time is 8-10 h.

[0016] The application has the following beneficial effects: 1. The ZIF-8 is used as a metal active center of a reactant, so that the reaction condition for preparing the catalyst is relatively mild, and the operation is relatively simple.

[0017] 2. The catalyst prepared by the application has low cost, is easy to recycle, can be recycled, and can greatly save cost.

[0018] 3. The catalyst prepared by the application has stable performance, is not volatile, has high hydrogenation activity, high tackification and desulfurization efficiency, is suitable for large-scale production, and has wide application prospects. DETAILED DESCRIPTION

[0019] The application provides a preparation method of a porous liquid catalyst, which comprises the following steps: The zinc nitrate and dimethylimidazole are mixed and heated in a solvent under ultrasonic wave, and after the precipitate is separated, centrifugal separation, drying are sequentially performed, and then the obtained solid is dispersed in [Bpy][Ntf2] to obtain a white solution, which is a porous liquid catalyst. The molar ratio of the zinc nitrate to the dimethylimidazole is 1:1.8-2.2, preferably 1:1.9-2.1, and more preferably 1:2.0.

[0020] In the application, the [Bpy][Ntf2] is preferably nitrogen-butyl pyridine triflate, and the zinc nitrate is preferably zinc nitrate hexahydrate.

[0021] In the application, the molar ratio of the zinc nitrate to the solvent is 0.00288-0.00488:1.25, preferably 0.00300-0.00388:1.25, and more preferably 0.00350:1.25; and the solvent is preferably methanol.

[0022] In the application, the power of the ultrasonic wave is 80-100 W, preferably 85-95 W, and more preferably 90 W; the time is 3-8 min, preferably 4-7 min, and more preferably 5-6 min; the heating temperature is 45-55℃, preferably 48-52℃, and more preferably 50℃; and the time is 3.5-4.5 h, preferably 4 h.

[0023] In the application, the process of separating the precipitate adopts vacuum suction filtration, the pressure of the vacuum suction filtration is 0.5-1.2 MPa, preferably 0.8-1.1 MPa, and more preferably 1 MPa, the funnel is a Buchner funnel, and the pump is a vacuum air pump.

[0024] In the application, the centrifuge used for centrifugal separation is a centrifuge, the speed of the centrifuge is 7000-11000 rpm, and the centrifugal time of the centrifuge is 3-8 min, more preferably 8000-11000 rpm, 4-7 min, and more preferably 9000 rpm, 6 min.

[0025] In the application, the drying is air drying, the drying temperature is 60-100℃, and the time is 2-5 h; preferably 70-90℃, 2-4 h; and more preferably 80℃, 3 h.

[0026] In the application, the mass ratio of the solid to [Bpy][Ntf2] is 1:15-20, and preferably 1:19.

[0027] The application also provides a porous liquid catalyst prepared by the preparation method.

[0028] The application further provides application of the porous liquid catalyst in hydrogenation and tackification of coal, which comprises the following steps: The porous liquid catalyst is reacted with the coal under a hydrogen atmosphere, and the reaction product is sequentially subjected to solid-liquid separation and drying, so as to obtain a solid product; The mass ratio of the coal to the porous liquid catalyst is 120-160:1, preferably 130-150:1, and more preferably 130:1.

[0029] In the application, the reaction temperature is 350-390 DEG C, preferably 360-380 DEG C, and more preferably 370-380 DEG C; the reaction time is 50-70 min, preferably 55-65 min, and more preferably 58-60 min; and the reaction pressure is 1-3 MPa, preferably 1.3-2.7 MPa, and more preferably 1.8-2.2 MPa.

[0030] In the application, the temperature rising rate for rising to the reaction temperature is 3-7 DEG C / min, preferably 4-6 DEG C / min, and more preferably 5 DEG C / min; the drying is vacuum drying, the temperature is 100-110 DEG C, preferably 102-108 DEG C, and more preferably 104-106 DEG C; and the time is 8-10 h, preferably 8.5-9.5 h, and more preferably 9 h.

[0031] The technical solutions provided by the application will be described in detail below in combination with the embodiments, but they should not be understood as limitations to the protection scope of the application.

[0032] Example 1

[0033] Preparation of the porous liquid catalyst: Zinc nitrate and dimethylimidazole (the molar ratio of zinc nitrate to dimethylimidazole is 1:2) are placed in a beaker at room temperature and heated and dissolved with methanol. The methanol solution of zinc nitrate and dimethylimidazole is mixed and heated and stirred on a magnetic stirrer at 50 DEG C for 4 h, and then ZIF-8 is separated by using a centrifuge at 9000 rpm for 6 min, and dried in a blast drying oven at 80 DEG C for 4 h to obtain ZIF-8 powder.

[0034] 0.25 g of ZIF-8 powder is measured and added to 4.75 g of [Bpy][Ntf2], and then ultrasonic treatment is performed for 20 min and stirring is performed for 3 h, so as to obtain the porous liquid catalyst, which is recorded as porous liquid ZIF-8-PL.

[0035] Example 2

[0036] The same as in Example 1, except that the molar ratio of zinc nitrate to dimethylimidazole is 1:1.8, and the mass ratio of ZIF-8 powder to [Bpy][Ntf2] is 1:20.

[0037] Example 3

[0038] The same as example 1, except that the molar ratio of zinc nitrate to dimethylimidazole is 1:2.2.

[0039] Example 4

[0040] The porous liquid ZIF-8-PL obtained in example 1 was added into the hydrogen donor solvent tetralin 60 mL to obtain a mixed solution, the mixed solution was treated by ultrasonic at 28℃, 80W for 3 min, then coal (30 g) and the catalyst prepared in the present example were jointly added into a 350 mL high-pressure reactor at a mass ratio of 130:1, hydrogen was introduced at room temperature and the pressure was adjusted to 1 MPa, the programmed temperature rising rate was set to 5℃ / min to rise to 350℃, and the reaction was carried out at 350℃ for 70 min, then the reactor was naturally cooled to room temperature in a closed state, then the reactor was opened, the solid and liquid products were separated, and dried at 100℃ for 10 h to obtain the final solid product. The performance analysis of the high-sulfur low-viscosity coal used and the solid product obtained is shown in Table 1 and Table 2, respectively.

[0041] Example 5

[0042] The porous liquid ZIF-8-PL obtained in example 1 was added into the hydrogen donor solvent tetralin 60 mL to obtain a mixed solution, the mixed solution was treated by ultrasonic at 28℃, 80W for 3 min, then coal (30 g) and the catalyst prepared in the present example were jointly added into a 350 mL high-pressure reactor at a mass ratio of 130:1, hydrogen was introduced at room temperature and the pressure was adjusted to 1.5 MPa, the programmed temperature rising rate was set to 5℃ / min to rise to 360℃, and the reaction was carried out at 360℃ for 65 min, then the reactor was naturally cooled to room temperature in a closed state, then the reactor was opened, the solid and liquid products were separated, and dried at 103℃ for 9.5 h to obtain the final solid product. The performance analysis of the high-sulfur low-viscosity coal used and the solid product obtained is shown in Table 1 and Table 2, respectively.

[0043] Example 6

[0044] The porous liquid ZIF-8-PL obtained in example 1 was added into the hydrogen donor solvent tetralin 60 mL to obtain a mixed solution, the mixed solution was treated by ultrasonic at 28℃, 80W for 3 min, then coal (30 g) and the catalyst prepared in the present example were jointly added into a 350 mL high-pressure reactor at a mass ratio of 130:1, hydrogen was introduced at room temperature and the pressure was adjusted to 2.0 MPa, the programmed temperature rising rate was set to 5℃ / min to rise to 370℃, and the reaction was carried out at 370℃ for 60 min, then the reactor was naturally cooled to room temperature in a closed state, then the reactor was opened, the solid and liquid products were separated, and dried at 105℃ for 9 h to obtain the final solid product. The performance analysis of the high-sulfur low-viscosity coal used and the solid product obtained is shown in Table 1 and Table 2, respectively.

[0045] Example 7

[0046] The porous liquid ZIF-8-PL obtained in Example 1 was added to the hydrogen-donating solvent tetralin 60 mL to obtain a mixed solution, the mixed solution was treated with ultrasound at 28°C and 80W for 3 min, then coal (30 g) and the catalyst prepared in the present example were jointly added into a 350 mL high-pressure reaction kettle at a mass ratio of 130: 1, hydrogen was introduced at room temperature and the pressure was adjusted to 2.5 MPa, the programmed temperature rising rate was set to 5°C / min to rise to 380°C, and the reaction was carried out at 380°C for 55 min, then the reaction kettle was opened under airtight condition, the solid and liquid products were separated, and dried at 107°C for 8.5 h to obtain the final solid product. The performance analysis of the high-sulfur low-viscosity coal used and the solid product obtained is shown in Table 1 and Table 2, respectively.

[0047] Example 8

[0048] The porous liquid ZIF-8-PL obtained in Example 1 was added to the hydrogen-donating solvent tetralin 60 mL to obtain a mixed solution, the mixed solution was treated with ultrasound at 28°C and 80W for 3 min, then coal (30 g) and the catalyst prepared in the present example were jointly added into a 350 mL high-pressure reaction kettle at a mass ratio of 130: 1, hydrogen was introduced at room temperature and the pressure was adjusted to 3 MPa, the programmed temperature rising rate was set to 5°C / min to rise to 390°C, and the reaction was carried out at 390°C for 50 min, then the reaction kettle was opened under airtight condition, the solid and liquid products were separated, and dried at 110°C for 8 h to obtain the final solid product. The performance analysis of the high-sulfur low-viscosity coal used and the solid product obtained is shown in Table 1 and Table 2, respectively.

[0049] Example 9

[0050] The porous liquid ZIF-8-PL obtained in Example 1 was added to the hydrogen-donating solvent tetralin 60 mL to obtain a mixed solution, the mixed solution was treated with ultrasound at 28°C and 80W for 3 min, then coal (30 g) and the catalyst prepared in the present example were jointly added into a 350 mL high-pressure reaction kettle at a mass ratio of 100: 1, hydrogen was introduced at room temperature and the pressure was adjusted to 1 MPa, the programmed temperature rising rate was set to 5°C / min to rise to 380°C, and the reaction was carried out at 380°C for 60 min, then the reaction kettle was opened under airtight condition, the solid and liquid products were separated, and dried at 110°C for 8 h to obtain the final solid product. The performance analysis of the high-sulfur low-viscosity coal used and the solid product obtained is shown in Table 1 and Table 2, respectively.

[0051] Example 10

[0052] The porous liquid ZIF-8-PL obtained in Example 1 was added to the hydrogen-donor solvent tetralin 60 mL to obtain a mixed solution, the mixed solution was treated by ultrasonic wave at 28℃, 80W for 3 min, then the coal (30 g) and the catalyst prepared in the present example were jointly added into a 350 mL high-pressure reactor at a mass ratio of 160:1, hydrogen was introduced at room temperature and the pressure was adjusted to 1 MPa, the programmed temperature rising rate was set to 5℃ / min to rise to 380℃, the reaction was carried out at 380℃ for 55 min, then the reactor was naturally cooled to room temperature in a closed state, then the reactor was opened, the solid and liquid products were separated, and dried at 110℃ for 8 h to obtain the final solid product. The performance analysis of the high-sulfur low-viscosity coal used and the solid product obtained is shown in Table 1 and Table 2, respectively.

[0053] Example 11

[0054] The porous liquid ZIF-8-PL obtained in Example 2 was added to the hydrogen-donor solvent tetralin to obtain a mixed solution, the mixed solution was treated by ultrasonic wave at 28℃, 80W for 3 min, then the coal (30 g) and the catalyst prepared in the present example were jointly added into a 350 mL high-pressure reactor at a mass ratio of 130:1, hydrogen was introduced at room temperature and the pressure was adjusted to 1 MPa, the programmed temperature rising rate was set to 5℃ / min to rise to 380℃, the reaction was carried out at 380℃ for 55 min, then the reactor was naturally cooled to room temperature in a closed state, then the reactor was opened, the solid and liquid products were separated, and dried at 110℃ for 8 h to obtain the final solid product. The performance analysis of the high-sulfur low-viscosity coal used and the solid product obtained is shown in Table 1 and Table 2, respectively.

[0055] Example 12

[0056] The porous liquid ZIF-8-PL obtained in Example 3 was added to the hydrogen-donor solvent tetralin to obtain a mixed solution, the mixed solution was treated by ultrasonic wave at 28℃, 80W for 3 min, then the coal (30 g) and the catalyst prepared in the present example were jointly added into a 350 mL high-pressure reactor at a mass ratio of 130:1, hydrogen was introduced at room temperature and the pressure was adjusted to 1 MPa, the programmed temperature rising rate was set to 5℃ / min to rise to 380℃, the reaction was carried out at 380℃ for 55 min, then the reactor was naturally cooled to room temperature in a closed state, then the reactor was opened, the solid and liquid products were separated, and dried at 110℃ for 8 h to obtain the final solid product. The performance analysis of the high-sulfur low-viscosity coal used and the solid product obtained is shown in Table 1 and Table 2, respectively.

[0057] Comparative Example 1

[0058] The 1-butyl-3-methylimidazole chloride is added into the hydrogen-donating solvent tetrahydronaphthalene to obtain a mixed solution, the mixed solution is treated by ultrasonic at 29°C and 85W for 4min, then the cobalt chloride hexahydrate is added into the ultrasonic-treated solution, and the solution is treated by ultrasonic again at 29°C and 15W for 9min until the solution is obviously sky blue, thereby the cobalt-based imidazole ionic liquid catalyst is obtained, wherein the molar ratio of the cobalt chloride hexahydrate to the 1-butyl-3-methylimidazole chloride is 0.6:1.

[0059] The high-sulfur low-viscosity coal (30g) and the catalyst prepared in the embodiment are jointly added into a 350mL high-pressure reaction kettle at a mass ratio of 140:1, hydrogen is introduced at room temperature and the pressure is adjusted to 2MPa, the programmed temperature rising rate is set to 5°C / min to rise to 360°C, the reaction is carried out at 360°C for 65min, then the reaction kettle is opened after natural cooling to room temperature in a closed state, the solid phase and liquid phase products are separated, and the solid phase product is dried at 103°C for 9.5h. The performance analysis of the high-sulfur low-viscosity coal used and the solid phase product obtained is shown in Table 1 and Table 2 respectively.

[0060] Table 1: Performance of high-sulfur low-viscosity coal used in Examples 4-8 and Comparative Example 1

[0061] Table 2: Performance of solid phase product obtained in Examples 4-8 and Comparative Example 1

[0062] Table 3: Performance of solid phase product obtained in Examples 9-11

[0063] It can be seen from the above embodiments that the present application provides a porous liquid catalyst, a preparation method thereof and an application thereof in the hydrogenation and viscosity increase of coal. As can be seen from Table 2, compared with the traditional metal-ionic liquid, the porous liquid catalyst prepared by the present application has good hydrogenation activity when applied to the hydrogenation and viscosity increase of coal, the coal's caking index GRI is obviously increased, and the total sulfur St,ad is also significantly decreased (up to more than 32%).

[0064] The above only describes the preferred embodiments of the present application, and it should be noted that for those skilled in the art, without departing from the principles of the present application, some improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A method for preparing a porous liquid catalyst, characterized in that, Includes the following steps: Zinc nitrate and dimethylimidazole were dissolved in a solvent, ultrasonically mixed and heated. After separating the precipitate, the mixture was centrifuged and dried sequentially. The resulting solid was then dispersed in [Bpy][Ntf2] to obtain a white solution, which is the porous liquid catalyst. The molar ratio of zinc nitrate to dimethylimidazole is 1:1.8~2.

2.

2. The method for preparing the porous liquid catalyst according to claim 1, characterized in that, The [Bpy][Ntf2] is nitrogen-butylpyridine trifluoromethanesulfonate, and the zinc nitrate is zinc nitrate trihexahydrate.

3. The method for preparing the porous liquid catalyst according to claim 1, characterized in that, The molar ratio of zinc nitrate to solvent is 0.00288~0.00488:1.25, and the solvent includes methanol.

4. The method for preparing the porous liquid catalyst according to any one of claims 1 to 3, characterized in that, The ultrasonic power is 80~100W, the time is 3~8min; the heating temperature is 45~55℃, the time is 3.5~4.5h.

5. The method for preparing the porous liquid catalyst according to claim 4, characterized in that, The mass ratio of the solid to [Bpy][Ntf2] is 1:15~20.

6. The porous liquid catalyst prepared by the preparation method according to any one of claims 1 to 5.

7. The application of the porous liquid catalyst according to claim 6 in the hydrogenation and thickening of coal, characterized in that, Includes the following steps: In a hydrogen atmosphere, a porous liquid catalyst is reacted with coal, and the reaction products are sequentially separated into solid and liquid phases and dried to obtain a solid product. The mass ratio of coal to porous liquid catalyst is 120~160:

1.

8. The application of the porous liquid catalyst according to claim 7 in the hydrogenation and thickening of coal, characterized in that, The reaction temperature is 350~390℃, the reaction time is 50~70min, and the reaction pressure is 1~3MPa.

9. The application of the porous liquid catalyst according to claim 7 or 8 in the hydrogenation and thickening of coal, characterized in that, The heating rate to the reaction temperature is 3~7℃ / min; the drying is vacuum drying at a temperature of 100~110℃ for 8~10h.

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