A catalyst preparation system for cracking and hydrogenation of macromolecular bridging bonds in coal

Abstract

The utility model discloses a kind of catalyst preparation systems of macromolecular bridge bond cleavage and hydrogenation in coal, including stirring tank, first reaction kettle, stationary tank, washing centrifuge, second reaction kettle, drying tower, tubular furnace and fixed bed.The preparation system of the utility model is combined with process, forms a complete system.Through optimizing the composition and structure of catalyst, the activity and stability of catalyst are improved, and the production cost of catalyst is reduced.The catalyst prepared by the utility model has a conversion rate of 100% for benzyl phenyl ether under mild conditions, and the change of temperature can change its selectivity.After being applied to macromolecular bridge bond cleavage and hydrogenation in coal, it can be separated by using density difference method, improve the recycling of catalyst, and realize the high value-added utilization of coal.

Description

Technical Field

[0001] This utility model relates to the field of coal conversion technology, and in particular to a catalyst preparation system for the cracking and hydrogenation of macromolecular bonds in coal. Background Technology

[0002] Coal is one of the world's richest fossil resources, with lignite accounting for almost half of global coal reserves. However, lignite's high moisture content, strong chemical reactivity, high degree of weathering, difficulty in storage and transportation, and low calorific value make it prone to environmental pollution when directly burned, limiting its traditional utilization methods. On the other hand, lignite has a high organic oxygen content, making it ideal as a raw material for obtaining high-value-added chemicals, especially oxygen-containing organic compounds. Generally, the main organic components in lignite are macromolecules containing aromatic rings, most of which are connected by bridging bonds, especially >CO- bridging bonds. Many aromatic rings also contain abundant side chains connected by >CO- bridging bonds. Therefore, cracking the bridging bonds and side chains in lignite can release a large amount of organic compounds (mainly oxygen-containing organic compounds), which is of great significance for realizing the high-value-added utilization of coal. Summary of the Invention

[0003] To address the aforementioned shortcomings of existing technologies, this invention provides a catalyst preparation system for the cracking and hydrogenation of macromolecular bonds in coal. This system combines a specific preparation process with a unique device structure to form a complete system, aiming to synthesize highly active and easily separable catalysts to achieve directional and mild conversion of coal, thereby realizing the high-value-added utilization of coal.

[0004] To achieve the aforementioned objectives, the technical solution adopted by this utility model is as follows:

[0005] A catalyst preparation system for cracking and hydrogenating macromolecular bonds in coal is provided, comprising a stirred tank, a first reaction vessel, a settling tank, a washing centrifuge, a second reaction vessel, a drying tower, a tubular furnace, and a fixed bed. The outlet of the stirred tank is connected to the inlet of the first reaction vessel via a first pipe; the outlet of the first reaction vessel is connected to the inlet of the settling tank via a second pipe; the outlet of the settling tank is connected to the inlet of the washing centrifuge via a third pipe; the outlet of the washing centrifuge is connected to the inlet of the second reaction vessel via a fourth pipe; the outlet of the second reaction vessel is connected to the inlet of the drying tower via a fifth pipe; the outlet of the drying tower is connected to the inlet of the tubular furnace via a sixth pipe; and the outlet of the tubular furnace is connected to the inlet of the fixed bed via a seventh pipe.

[0006] Furthermore, an ultrasonic dispersion module is installed inside the mixing tank, which includes a transducer and a vibrating rod.

[0007] Furthermore, electromagnetic valves are installed on the first, second, third, fourth, fifth, sixth, and seventh pipelines.

[0008] Furthermore, delivery pumps are installed on the first, second, third, fourth, fifth, sixth, and seventh pipelines.

[0009] Furthermore, the first, second, third, fourth, fifth, sixth, and seventh pipelines all employ pipeline screw conveyors.

[0010] The beneficial effects of this utility model are as follows:

[0011] This invention combines a specific preparation process with a unique device structure to form a complete system, reducing the production cost of the catalyst. By optimizing the composition and structure of the catalyst, its activity and stability are improved. Furthermore, the prepared catalyst achieves 100% conversion of benzylphenyl ether under mild conditions, and its selectivity changes with temperature. When applied to the cracking of macromolecular bridge bonds and hydrogenation in coal, it can be separated using a density difference method, improving the catalyst's recyclability. This is of great significance for achieving high-value utilization of coal.

[0012] This invention improves the activity and stability of the catalyst by optimizing its composition and structure (molar ratio, temperature, reaction time, etc.); it combines a specific preparation process with a unique device structure to form a complete system, reducing the production cost of the catalyst; the catalyst prepared by this invention can be separated by density difference method after cracking of macromolecular bridge bonds in coal and hydrogenation, improving the recyclability of the catalyst. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the catalyst preparation system for the cracking and hydrogenation of macromolecular bridge bonds in coal according to this invention.

[0014] Figure 2 The H2-TPR curve of Ni-Cs-Al-LDO;

[0015] Figure 3 A flowchart illustrating the process of using NiCs / Al2O3 prepared according to this invention for BOB bridge bond cleavage and hydrogenation;

[0016] Figure 4 To obtain the flowchart of LR;

[0017] Figure 5 A flowchart illustrating the application of NiCs / Al2O3 prepared according to this invention for the cracking of macromolecular bridging bonds and hydrogenation in coal;

[0018] The symbols for the main components in the diagram are explained below:

[0019] 1. Mixing tank; 2. First reaction vessel; 3. Settling tank; 4. Washing centrifuge; 5. Second reaction vessel; 6. Reaction vessel; 7. Tube furnace; 8. Fixed bed. Detailed Implementation

[0020] The specific embodiments of this utility model are described below to enable those skilled in the art to understand this utility model. However, it should be understood that this utility model is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of this utility model as defined and determined by the appended claims, these changes are obvious. All utility model creations utilizing the concept of this utility model are within the scope of protection.

[0021] like Figure 1As shown, a catalyst preparation system for the cracking and hydrogenation of macromolecular bonds in coal includes: a stirred tank 1, a first reaction vessel 2, a settling tank 3, a washing centrifuge 4, a second reaction vessel 5, a drying tower 6, a tubular furnace 7, and a fixed bed 8. The stirred tank 1 can be a DVP-1000L, the first reaction vessel 2 can be a GSHF-500, the settling tank 3 can be a DVP-800, the washing centrifuge 4 can be a LW520×1500-N, the second reaction vessel 5 can be a GR-300T, the drying tower 6 can be an LPG-50, the tubular furnace 7 can be an OTF-1200X-S-VT, and the fixed bed can be a KDB-Ⅱ. The discharge port of the mixing tank 1 is connected to the inlet of the first reaction vessel 2 via a first pipe. The discharge port of the first reaction vessel 2 is connected to the inlet of the settling tank 3 via a second pipe. The discharge port of the settling tank 3 is connected to the inlet of the washing centrifuge 4 via a third pipe. The discharge port of the washing centrifuge 4 is connected to the inlet of the second reaction vessel 5 via a fourth pipe. The discharge port of the second reaction vessel 5 is connected to the inlet of the drying tower 6 via a fifth pipe. The discharge port of the drying tower 6 is connected to the inlet of the tubular furnace 7 via a sixth pipe. The discharge port of the tubular furnace 7 is connected to the inlet of the fixed bed 8 via a seventh pipe. An ultrasonic dispersion module is installed inside the mixing tank 1. The ultrasonic dispersion module includes a transducer and a vibrating rod. The ultrasonic dispersion module helps to better dissolve the raw materials into a mixed salt solution. Electromagnetic valves are installed on the first, second, third, fourth, fifth, sixth, and seventh pipes. The electromagnetic valves are used to control the fluid flow between the various devices. Each of the first, second, third, fourth, fifth, sixth, and seventh pipelines is equipped with a conveying pump, which provides the power to transport the fluid and ensures the smooth operation of each process step. In another embodiment, the first, second, third, fourth, fifth, sixth, and seventh pipelines can be preferably constructed using a pipeline screw conveyor, which can also achieve the same conveying function as the pumps and pipelines.

[0022] A catalyst preparation process for the cracking and hydrogenation of macromolecular bonds in coal includes the following steps:

[0023] S1: Weigh the raw materials according to the specified ratio and add them to the ultrasonic dispersion tank 1. The raw material ratio is as follows: In the process, deionized water is added to the mixing tank 1, and ultrasonic operation is performed for 30 minutes to dissolve the raw materials into a mixed salt solution; the mixing tank 1 has an ultrasonic dispersion function, for example, the mixing tank 1 can be an H3000L ultrasonic mixing tank.

[0024] S2: The mixed salt solution is transferred to the first reaction vessel 2, stirred and heated at 125°C, and refluxed for 6 hours; the first reaction vessel 2 is equipped with a stepped temperature control system;

[0025] S3: The material generated in the first reaction vessel 2 is transferred to the settling tank 3 and aged at room temperature for 12 hours;

[0026] S4: Use a continuous washing centrifuge 4 to wash and centrifuge the material generated in the settling tank 3 multiple times until the pH value reaches 7.

[0027] S5: The material obtained from the washing centrifuge 4 is conveyed to the second reaction vessel 5, ammonia water is added to cover the material, the filter cake is dissolved under ultrasonic radiation, and then CsOH is added. CsOH reacts with... The proportion satisfies Continue ultrasonic irradiation for 15 minutes to mix evenly, then stir and heat at 125°C, and reflux for 6 hours.

[0028] S6: Use spray drying tower 6 to dry the material output from the second reactor 5 to obtain Ni-Cs-Al-LDH;

[0029] S7: The obtained Ni-Cs-Al-LDH was calcined in a tube furnace 7 under air atmosphere at a temperature of 5℃ / min to 500℃ for 2h to obtain Ni-Cs-Al-LDO.

[0030] S8: The obtained Ni-Cs-Al-LDO was reduced in a fixed bed 8 under H2 atmosphere at a temperature of 5℃ / min to 500℃ for 3h to obtain NiCs / Al2O3 catalyst.

[0031] The catalyst prepared by this invention achieves 100% conversion of benzylphenyl ether under mild conditions, and its selectivity changes with temperature. Specific implementation methods are as follows:

[0032] like Figure 2 As shown, the NH3-TPD curves of Ni / Al2O3 and NiCs / Al2O3 catalysts are obtained by temperature-programmed desorption (TPD). The desorption peak at 641℃ in NiCs / Al2O3 is attributed to a superacidic site, confirming the successful construction of a superacidic active center in the catalyst, indicating that the NiCs / Al2O3 catalyst has achieved the expected preparation goal. Figure 3As shown, 0.05 g of NiCs / Al2O3, 0.1 g of benzyl phenyl ether (BOB), and 20 mL of n-pentane solvent were added to a high-pressure reactor. The air inside the reactor was first replaced three times with N2, then three times with H2. H2 was then introduced into the reactor to a pressure of 1 MPa. The reaction temperature was set at 120 °C, the stirring speed at 300 rpm, and the reaction time at 2 h. After the reaction, the liquid product was separated from the catalyst by filtration. The catalyst was recovered after washing with n-pentane. The liquid product was collected and analyzed by GC-MS to calculate the conversion and selectivity. Following the same process, the reaction temperature was changed to obtain the conversion and selectivity at 140 °C and 160 °C, respectively. The reaction performance of the catalyst at different reaction temperatures (120 °C, 140 °C, and 160 °C) was evaluated, as shown in the table below.

[0033] Evaluation table of catalyst reaction performance at different reaction temperatures

[0034]

[0035] As shown in the table above, high conversion rates of benzylphenyl ether were observed at reaction temperatures of 120℃, 140℃, and 160℃, and the selectivity for benzylphenyl ether changed with temperature variations. Based on these results, the NiCs / Al2O3 catalyst prepared according to this invention is relatively simple to prepare, exhibits good hydrogenation performance, and can achieve complete conversion of benzylphenyl ether under mild conditions.

[0036] The catalyst prepared by this invention, when applied to the cracking of macromolecular bridge bonds and hydrogenation of Pakistani coal, can indeed be separated using the density difference method. The specific implementation method is as follows:

[0037] Accurately weigh 30g of Pakistani lignite into a 1000mL beaker, and add an equal volume of 600mL of acetone / carbon disulfide mixed solvent (IMCDSAMS). Place the beaker in an ultrasonic cleaner and perform continuous ultrasonic extraction at room temperature for 0.5h. Repeat the extraction at least 30 times to ensure the extract is nearly colorless. Filter the extracted mixture to obtain the extractable portion (EP) and extraction residue (ER). The dry ash-free yield of EP is the ratio of the mass of EP to the mass of dry ash-free DL; in this experiment, the YEP / DL ratio was 16.09%.

[0038] 10 g of ER was placed in a 500 mL beaker, and 450 mL of carbon tetrachloride was added. The mixture was then ultrasonically extracted for 0.5 h. The extracted mixture was transferred to a separatory funnel and allowed to stand for 48 h. After processing, a clear stratification phenomenon was observed in the separatory funnel. The heavy residue (HR) (4.37 g) at the bottom and the light residue (LR) (6.241 g) outside the bottom were released sequentially with the solvent. The obtained LR was then filtered and vacuum dried to remove the solvent, and stored in a nitrogen-filled desiccator for later use.

[0039] DL, ER, and LR underwent industrial and elemental analysis, and were characterized using thermogravimetric analysis (TGA) and FTIR. Specifically, the flowchart for obtaining the LR result is shown below. Figure 4 As shown.

[0040] 1 g of LR, 0.3 g of NiCs / Al2O3, and 20 mL of n-pentane were placed in a 100 mL high-pressure reactor and reacted at 180 °C and 1 HP 1 MPa for 2 h. The reaction mixture was then transferred and filtered under reduced pressure to obtain a residue and a filtrate. The residue was repeatedly extracted with n-pentane using ultrasonic extraction. The extract and filtrate were combined to obtain the soluble component SPA-1, and the product composition was analyzed by GC / MS. A detailed flowchart for the cracking and hydrogenation of macromolecular bonds in coal is shown below. Figure 5 As shown.

Claims

1. A catalyst preparation system for the cracking and hydrogenation of macromolecular bonds in coal, characterized in that, The system includes a mixing tank (1), a first reaction vessel (2), a settling tank (3), a washing centrifuge (4), a second reaction vessel (5), a drying tower (6), a tubular furnace (7), and a fixed bed (8). The outlet of the mixing tank (1) is connected to the inlet of the first reaction vessel (2) via a first pipe. The outlet of the first reaction vessel (2) is connected to the inlet of the settling tank (3) via a second pipe. The outlet of the settling tank (3) is connected to the inlet of the washing centrifuge (4) via a third pipe. The outlet of the washing centrifuge (4) is connected to the inlet of the second reaction vessel (5) via a fourth pipe. The outlet of the second reaction vessel (5) is connected to the inlet of the drying tower (6) via a fifth pipe. The outlet of the drying tower (6) is connected to the inlet of the tubular furnace (7) via a sixth pipe. The outlet of the tubular furnace (7) is connected to the inlet of the fixed bed (8) via a seventh pipe.

2. The catalyst preparation system for the cracking and hydrogenation of macromolecular bonds in coal according to claim 1, characterized in that, The mixing tank (1) is equipped with an ultrasonic dispersion module, which includes a transducer and a vibrating rod.

3. The catalyst preparation system for the cracking and hydrogenation of macromolecular bonds in coal according to claim 1, characterized in that, Electromagnetic valves are installed on the first, second, third, fourth, fifth, sixth, and seventh pipelines.

4. The catalyst preparation system for the cracking and hydrogenation of macromolecular bonds in coal according to claim 1, characterized in that, Each of the first, second, third, fourth, fifth, sixth, and seventh pipelines is equipped with a delivery pump.

5. The catalyst preparation system for the cracking and hydrogenation of macromolecular bonds in coal according to claim 1, characterized in that, The first, second, third, fourth, fifth, sixth and seventh pipelines all use pipeline screw conveyors.

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