System for preparing catalyst by using underground coal gasification byproducts

Abstract

The utility model relates to the technical field of catalyst preparation, and discloses a system for preparing a catalyst by using underground coal gasification byproducts. The catalyst system comprises an injection well, a product well, a conveying pipeline, a separation device, an ammonia absorption tower and a carbonization tower, the injection well is communicated with the product well, the product well conveys generated synthesis gas into the separation device through the conveying pipeline, the separation device is used for extracting ammonia gas and carbon dioxide, and the ammonia absorption tower is used for absorbing ammonia gas. The separation device is respectively connected with the ammonia absorption tower and the carbonization tower through conveying pipelines, the ammonia absorption tower is connected with the carbonization tower through a conveying pipeline, the carbonization tower is connected with a filter through a conveying pipeline, and two discharge holes are formed in the filter; the catalyst system is used for producing sodium carbonate by taking ammonia gas obtained by recovering phenol ammonia and carbon dioxide extracted from synthesis gas as raw materials, so that resources are recycled, and the target requirements of environmental protection and carbon emission reduction are met.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, specifically relating to a catalyst preparation system using underground coal gasification byproducts. Background Technology

[0002] Underground coal gasification (ISC) is a process that directly converts coal into gaseous products through controlled combustion (incomplete combustion) and gasification reactions in underground coal seams. The product gas, commonly known as syngas, can be used as feedstock for downstream processes such as fuel production, chemical production, and power generation. This process integrates well construction and completion, underground coal mining, and coal gasification technologies, offering advantages such as high safety, low investment, high efficiency, and low pollution.

[0003] By drilling directly into the coal seam, an effective channel is provided for oxidant injection and product gas output. One well used for oxidant injection is called an "injection well," and the other well used for producing product gas is called a "product well."

[0004] When an injection well, a product well, and a horizontal channel connect a coal seam, this structure is called an underground coal gasification (ISC) unit or well pair. An ISC unit includes a combustion zone, a gasification zone, and a pyrolysis zone. The product gas (crude syngas) generated through underground coal gasification typically contains syngas (CO, CO2, H2, CH4, etc.) and other impurities (particles, water, coal tar, H2S, NH4, COS, etc.). The crude syngas is transported to the surface via the product well and then through surface pipelines to downstream units for processing and application.

[0005] Existing underground coal gasification systems directly filter ammonia from phenols and carbon dioxide from syngas before releasing it into the air. While this does not cause air pollution, it also fails to allow for the secondary use of ammonia and carbon dioxide, resulting in relatively low resource utilization. Therefore, a gasification system is needed to address this issue. Summary of the Invention

[0006] The purpose of this invention is to provide a catalyst system with a simple structure and reasonable design in order to solve the above problems.

[0007] This utility model achieves the above objectives through the following technical solutions:

[0008] A catalyst preparation system utilizing coal underground gasification byproducts includes: an injection well, a product well, a conveying pipeline, a separation device, an ammonia absorption tower, and a carbonization tower. The injection well is connected to the product well. The product well delivers the generated syngas to the separation device via the conveying pipeline. The separation device is used to extract ammonia and carbon dioxide. The separation device is connected to the ammonia absorption tower and the carbonization tower via conveying pipelines. The ammonia absorption tower is connected to the carbonization tower via a conveying pipeline. The carbonization tower is connected to a filter via a conveying pipeline. The filter has two discharge ports. The two discharge ports are connected to a sodium chloride solution extraction device and a sodium bicarbonate solid treatment device via conveying pipelines. The discharge end of the sodium chloride solution extraction device is connected to the ammonia absorption tower via a conveying pipeline. The discharge end of the sodium bicarbonate solid treatment device is connected to the conveying pipeline between the carbon dioxide extraction device and the carbonization tower via a conveying pipeline.

[0009] As a further optimization of this utility model, the separation device includes a phenol-ammonia recovery device and a carbon dioxide extraction device. The phenol-ammonia recovery device is used to separate and recover ammonia, and the carbon dioxide extraction device is used to extract carbon dioxide. The phenol-ammonia recovery device is connected to an ammonia absorption tower through a conveying pipeline, and the carbon dioxide extraction device is connected to a carbonization tower through a conveying pipeline.

[0010] As a further optimization of this utility model, a first water pump is connected to the conveying pipeline between the ammonia absorption tower and the carbonization tower.

[0011] As a further optimization of this utility model, a circulation pump is provided on one side of the ammonia absorption tower, and the input and output ends of the circulation pump are connected to the ammonia absorption tower through a delivery pipeline.

[0012] As a further optimization of this utility model, a level gauge is installed at the bottom of the ammonia absorption tower to measure the liquid level height at the bottom of the ammonia absorption tower.

[0013] As a further optimization of this utility model, the sodium chloride solution extraction device includes a cooling and stirring tank, a centrifuge, an alkaline mother liquor storage tank, a brine pump, and a powder tank. The cooling and stirring tank, centrifuge, alkaline mother liquor storage tank, and brine pump are connected in sequence through a conveying pipeline. The powder tank is connected to the cooling and stirring tank through a conveying pipeline. The cooling and stirring tank is connected to a filter through a conveying pipeline. The brine pump is connected to an ammonia absorption tower through a conveying pipeline.

[0014] As a further optimization of this utility model, the sodium chloride solution extraction device further includes a dryer and a first collection tank. The dryer is connected to a centrifuge via a conveying pipe, and the first collection tank is connected to the dryer via a conveying pipe.

[0015] As a further optimization of this utility model, the sodium bicarbonate solid processing device includes a calcining furnace and a carbon dioxide condenser connected in sequence by a conveying pipeline. The calcining furnace is connected to a filter through a conveying pipeline, and the carbon dioxide condenser is connected to a conveying pipeline between a carbon dioxide extraction device and a carbonization tower through a conveying pipeline.

[0016] As a further optimization of this utility model, the sodium bicarbonate solid treatment device also includes a wastewater treatment device, which is connected to a carbon dioxide condenser via a conveying pipeline.

[0017] As a further optimization of this utility model, the system also includes: a second collection tank, a catalyst injection device, and a pure water device. The calcining furnace is also connected to the second collection tank, the catalyst injection device, and the injection well in sequence via a conveying pipeline. The pure water device is connected to the cooling and stirring tank, the catalyst injection device, and the conveying pipeline between the catalyst injection device and the injection well via a conveying pipeline.

[0018] The beneficial effects of this invention are as follows: This invention uses ammonia obtained from phenol-ammonia recovery and carbon dioxide extracted from syngas as raw materials to produce sodium carbonate, realizing resource reuse and meeting environmental protection and carbon emission reduction targets; the produced sodium carbonate acts as a catalyst in underground coal gasification, improving syngas yield and quality, reducing waste gas content in coal gas composition, reducing carbon dioxide generation, and improving thermal efficiency. At the same time, it reduces production and operating costs and improves the economic benefits of underground coal gasification; furthermore, the prepared sodium carbonate can also be used for other purposes such as wastewater treatment. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0020] In the diagram: 1. Phenol and ammonia recovery unit; 2. Carbon dioxide extraction unit; 3. Circulating pump; 4. Ammonia absorption tower; 5. First water pump; 6. Carbonization tower; 7. Filter; 8. Calcination furnace; 9. Carbon dioxide condenser; 10. Cooling and stirring tank; 11. Centrifuge; 12. Dryer; 13. First collection tank; 14. Alkali mother liquor storage tank; 15. Brine pump; 16. Powder tank; 17. Second collection tank; 18. Catalyst injection unit; 19. Pure water unit; 20. Fuel; 101. Injection well; 102. Product well; 103. Wastewater treatment unit. Detailed Implementation

[0021] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0022] Example 1

[0023] like Figure 1 As shown, a catalyst preparation system utilizing coal underground gasification byproducts includes: an injection well 101, a product well 102, a conveying pipeline, a separation device, an ammonia absorption tower 4, and a carbonization tower 6. The injection well 101 is connected to the product well 102. The product well 102 conveys the generated syngas to the separation device through the conveying pipeline. The separation device is used to extract ammonia and carbon dioxide. The separation device is connected to the ammonia absorption tower 4 and the carbonization tower 6 through the conveying pipeline. The ammonia absorption tower 4 is connected to the carbonization tower 6 through the conveying pipeline. The carbonization tower 6 is connected to a filter 7 through the conveying pipeline. The filter 7 has two discharge ports. The two discharge ports are connected to a sodium chloride solution extraction device and a sodium bicarbonate solid treatment device through the conveying pipeline, respectively. The discharge end of the sodium chloride solution extraction device is connected to the ammonia absorption tower 4 through the conveying pipeline. The discharge end of the sodium bicarbonate solid treatment device is connected to the conveying pipeline between the carbon dioxide extraction device 2 and the carbonization tower 6 through the conveying pipeline.

[0024] It should be noted that the filter 7 can be a rotary drum vacuum filter 7, a rubber belt vacuum filter 7, or a centrifugal filter 7, in order to improve filtration efficiency and reduce the moisture content in the filter cake;

[0025] The calcining furnace 8 is used to heat wet sodium bicarbonate. Its furnace body can be made of high-temperature resistant alloy steel or carbon steel lined with refractory material.

[0026] Furthermore, the separation device includes a phenol-ammonia recovery unit 1 and a carbon dioxide extraction unit 2. The phenol-ammonia recovery unit 1 is used to separate and recover ammonia, and the carbon dioxide extraction unit 2 is used to extract carbon dioxide. The phenol-ammonia recovery unit 1 is connected to the ammonia absorption tower 4 through a conveying pipeline, and the carbon dioxide extraction unit 2 is connected to the carbonization tower 6 through a conveying pipeline.

[0027] Specifically, a regulating valve and a flow meter are installed on the conveying pipeline connecting the phenol-ammonia recovery unit 1 and the ammonia absorption tower 4.

[0028] It should be noted that the phenol and ammonia recovery unit 1 is used to separate and recover substances such as phenols and ammonia nitrogen in coal gas water, so as to realize the recycling of resources. The recovered ammonia gas can be used as raw material gas to prepare sodium carbonate catalyst.

[0029] Carbon dioxide extraction unit 2: used to extract carbon dioxide from syngas, and the extracted carbon dioxide is used as a raw material to prepare sodium carbonate catalyst.

[0030] It should be noted that the ammonia gas generated by the phenol-ammonia recovery unit 1 enters from the bottom of the ammonia absorption tower 4, and the sodium chloride solution is fed from the top of the ammonia absorption tower 4, so that the ammonia gas and the sodium chloride solution can fully contact and react to absorb the ammonia gas to form ammonia brine.

[0031] It should be noted that carbon dioxide flows upward from the bottom of carbonization tower 6, while the sodium chloride solution absorbing ammonia flows downward from the top of carbonization tower 6. This ensures sufficient contact between the gas and liquid components, allowing the reaction to proceed continuously and efficiently. Carbonization tower 6 is equipped with a stirrer at the bottom; various types of stirrers, such as paddle, turbine, or propeller stirrers, can be used. The stirrer allows carbon dioxide gas to be better dispersed in the ammonia-water brine, increasing the gas-liquid contact area and improving the reaction rate. Simultaneously, the stirrer prevents sodium bicarbonate crystals from precipitating and accumulating within the tower, promoting crystal suspension and formation.

[0032] Furthermore, a first water pump 5 is connected to the conveying pipeline between the ammonia absorption tower 4 and the carbonization tower 6.

[0033] Furthermore, a circulation pump 3 is installed on one side of the ammonia absorption tower 4, and both the input and output ends of the circulation pump 3 are connected to the ammonia absorption tower 4 through conveying pipes.

[0034] Furthermore, a level gauge is installed at the bottom of the ammonia absorption tower 4 to measure the liquid level height at the bottom of the ammonia absorption tower 4.

[0035] It should be noted that the circulating pump 3 can draw the sodium chloride solution from the bottom of the tower to the top of the tower, so that the ammonia gas and the sodium chloride solution can come into full contact, ensuring that the sodium chloride solution can form a stable circulating flow in the tower, which meets the requirements of the ammonia absorption process.

[0036] It should be further noted that the distance between the inlet pipe of the circulating pump 3 (i.e., the conveying pipe connecting the water inlet end of the circulating pump 3 and the ammonia absorption tower 4) and the tower wall should be 0.5-1 times the diameter of the inlet pipe, and the end of the inlet pipe should be about 0.3-0.8 meters from the bottom of the tower, maintaining a certain safe distance from the ammonia inlet to prevent the pump from sucking in too much ammonia and causing gas binding.

[0037] Furthermore, the sodium chloride solution extraction device includes a cooling and stirring tank 10, a centrifuge 11, an alkali mother liquor storage tank 14, a brine pump 15, and a powder tank 16. The cooling and stirring tank 10, centrifuge 11, alkali mother liquor storage tank 14, and brine pump 15 are connected in sequence through a conveying pipeline. The powder tank 16 is connected to the cooling and stirring tank 10 through a conveying pipeline. The cooling and stirring tank 10 is connected to the filter 7 through a conveying pipeline. The brine pump 15 is connected to the ammonia absorption tower 4 through a conveying pipeline.

[0038] It should be noted that the powder container 16 is used to hold sodium chloride powder, which facilitates the addition of sodium chloride powder to the cooling and stirring container 10.

[0039] The cooling mixing tank 10 is made of corrosion-resistant materials such as stainless steel. It is equipped with a cooling mechanism, thermometer, level gauge, etc., to control the temperature of the liquid inside the tank. The mixing device inside the tank consists of a motor, reducer and mixing blades to achieve full mixing of materials.

[0040] Furthermore, the sodium chloride solution extraction device also includes a dryer 12 and a first collection tank 13. The dryer 12 is connected to the centrifuge 11 via a conveying pipe, and the first collection tank 13 is connected to the dryer 12 via a conveying pipe.

[0041] It should be noted that the first collection tank 13 is used to collect ammonium chloride;

[0042] Centrifuge 11 uses centrifugal force to separate ammonium chloride suspension. Specifically, when the ammonium chloride suspension enters the drum of centrifuge 11, the high-speed rotating drum generates a strong centrifugal force. Under the action of centrifugal force, the denser ammonium chloride solid particles are thrown towards the drum wall, while the less dense mother liquor remains near the center of the drum, thus achieving the separation of ammonium chloride solid and mother liquor.

[0043] Furthermore, the sodium bicarbonate solid processing device includes a calcining furnace 8 and a carbon dioxide condenser 9 connected in sequence by conveying pipes. The calcining furnace 8 is connected to the filter 7 via conveying pipes, and the carbon dioxide condenser 9 is connected to the conveying pipe between the carbon dioxide extraction device 2 and the carbonization tower 6 via conveying pipes.

[0044] Specifically, a regulating valve and a flow meter are installed at the end of the conveying pipeline between the carbon dioxide extraction device 2 and the carbonization tower 6, near the carbonization tower 6.

[0045] It should be noted that both the dryer 12 and the calcining furnace 8 are equipped with heating mechanisms, and the fuel 20 for the heating mechanisms is natural gas or coal gas after underground coal gasification syngas treatment.

[0046] Dryer 12 is used to heat wet ammonium chloride. Dryer 12 is made of stainless steel, corrosion-resistant carbon steel, or special high-temperature resistant alloy materials.

[0047] The carbon dioxide condenser 9 mainly consists of a tank, a cooling mechanism, an inlet, and an outlet. The tank is made of stainless steel and other high-pressure and corrosion-resistant materials.

[0048] Furthermore, the sodium bicarbonate solid treatment device also includes a wastewater treatment device 103, which is connected to the carbon dioxide condenser 9 via a conveying pipeline.

[0049] Furthermore, the system also includes: a second collection tank 17, a catalyst injection device 18, and a pure water device 19. The calcining furnace 8 is also connected to the second collection tank 17, the catalyst injection device 18, and the injection well 101 in sequence via a conveying pipe. The pure water device 19 is connected to the cooling stirring tank 10, the catalyst injection device 18, and the conveying pipe between the catalyst injection device 18 and the injection well 101 via a conveying pipe.

[0050] It should be noted that the second collection tank 17 is used to collect sodium carbonate.

[0051] Workflow: Syngas produced by underground coal gasification is transported to the surface unit via product well 102. The syngas is washed with water to produce coal gas water, which is then processed by phenol and ammonia recovery unit 1 to produce ammonia. Ammonia is absorbed in the ammonia absorption tower 4 by a counter-current contact reaction with sodium chloride brine at the bottom of the tower. The ammonia flow rate and speed are controlled by regulating valve and flow meter 1. A circulation pump 3 is installed outside the ammonia absorption tower 4 to form a stable circulation flow of sodium chloride solution in the tower, thereby improving the ammonia absorption efficiency. Then, the ammonia brine is transported to the upper part of the carbonization tower 6 by the first water pump 5.

[0052] Simultaneously, the carbon dioxide extracted from the underground coal gasification syngas by the carbon dioxide extraction device 2, along with the carbon dioxide recovered by the subsequent carbon dioxide condenser 9, enters the bottom of the carbonization tower 6. After entering the tower, the ammonia brine flows downwards uniformly under gravity or other forces, contacting the rising carbon dioxide in a counter-current manner. The flow rate and velocity of the carbon dioxide gas are controlled by regulating valve 2 and flow meter 2 to ensure a thorough reaction with the ammonia brine. This counter-current contact method improves contact efficiency and reaction degree (the reaction temperature is controlled at 30℃-40℃; at this temperature, the solubility of sodium bicarbonate is low, making it easier to precipitate from the solution, which is beneficial for the reaction to proceed in the direction of sodium bicarbonate formation). During the reaction, the bottom agitator needs to be used to continuously stir the mixture to ensure sufficient contact between carbon dioxide and ammonia brine and to ensure uniform reaction, preventing excessive or insufficient reaction in some areas. The reaction produces sodium bicarbonate precipitate and a mixed solution. The agitator at the bottom of carbonation tower 6 can prevent sodium bicarbonate from precipitating to the bottom of the tower. The mixed solution at the bottom of carbonation tower 6 is filtered by filter 7 to separate the sodium bicarbonate solid from the mother liquor. The separated wet sodium bicarbonate material is transported to calcining furnace 8. The wet sodium bicarbonate material in calcining furnace 8 is heated by fuel 20. The heating temperature is controlled at about 100℃-200℃. Under the heating conditions, sodium bicarbonate undergoes a decomposition reaction to produce sodium carbonate, carbon dioxide and water vapor.

[0053] When catalytic gasification is required, the sodium carbonate catalyst is dissolved using pure water produced by the pure water unit 19, and the dissolved sodium carbonate catalyst is then transported to the underground coal gasifier via the catalyst injection unit 18 to participate in the gasification reaction. When catalytic gasification is not required, the pure water unit 19 can directly supply pure water to the injection well 101.

[0054] The carbon dioxide gas and water vapor produced by the calcining furnace 8 are passed through the carbon dioxide condenser 9 to remove water vapor and a small amount of entrained sodium carbonate solid. The condensed carbon dioxide gas is then transported to the bottom of the carbonization tower 6 for further recycling. The discharged wastewater is transported to the wastewater treatment device 103 for further treatment.

[0055] The mother liquor after sodium bicarbonate separation via filter 7 is transported to cooling and stirring tank 10. Sodium chloride powder and pure water produced by pure water device 19 are added to cooling and stirring tank 10, and the temperature is controlled at 5℃-10℃ by a cooling device. Taking advantage of the property that ammonium chloride has reduced solubility at low temperatures, ammonium chloride crystallizes out separately, thereby separating ammonium chloride from other components in the mother liquor. After filtration by centrifuge 11, wet ammonium chloride material is obtained and sent to a dryer for heating to obtain solid ammonium chloride product. The filtered solution (sodium chloride solution) is transported to alkali mother liquor storage tank 14 and then pumped to ammonia absorption tower 4 via brine pump 15 for circulation and reaction.

[0056] The embodiments described above are merely examples of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.

Claims

1. A catalyst preparation system using underground coal gasification byproducts, characterized in that, include: The system comprises an injection well, a product well, a conveying pipeline, a separation device, an ammonia absorption tower, and a carbonization tower. The injection well is connected to the product well. The product well delivers the generated syngas to the separation device via the conveying pipeline. The separation device is used to extract ammonia and carbon dioxide. The separation device is connected to the ammonia absorption tower and the carbonization tower via conveying pipelines. The ammonia absorption tower is connected to the carbonization tower via a conveying pipeline. The carbonization tower is connected to a filter via a conveying pipeline. The filter has two discharge ports. The two discharge ports are connected to a sodium chloride solution extraction device and a sodium bicarbonate solid treatment device via conveying pipelines. The discharge end of the sodium chloride solution extraction device is connected to the ammonia absorption tower via a conveying pipeline. The discharge end of the sodium bicarbonate solid treatment device is connected to the conveying pipeline between the carbon dioxide extraction device and the carbonization tower via a conveying pipeline.

2. The catalyst preparation system using underground coal gasification byproducts according to claim 1, characterized in that, The separation device includes a phenol-ammonia recovery device and a carbon dioxide extraction device. The phenol-ammonia recovery device is used to separate and recover ammonia, and the carbon dioxide extraction device is used to extract carbon dioxide. The phenol-ammonia recovery device is connected to an ammonia absorption tower via a conveying pipeline, and the carbon dioxide extraction device is connected to a carbonization tower via a conveying pipeline.

3. A catalyst preparation system using underground coal gasification byproducts according to claim 2, characterized in that, A first water pump is connected to the conveying pipeline between the ammonia absorption tower and the carbonization tower.

4. A catalyst preparation system using underground coal gasification byproducts according to claim 3, characterized in that, A circulation pump is installed on one side of the ammonia absorption tower, and both the input and output ends of the circulation pump are connected to the ammonia absorption tower through delivery pipelines.

5. A catalyst preparation system using underground coal gasification byproducts according to claim 3, characterized in that, A level gauge is installed at the bottom of the ammonia absorption tower to measure the liquid level at the bottom of the tower.

6. A catalyst preparation system using underground coal gasification byproducts according to claim 1, characterized in that, The sodium chloride solution extraction device includes a cooling and stirring tank, a centrifuge, an alkali mother liquor storage tank, a brine pump, and a powder tank. The cooling and stirring tank, centrifuge, alkali mother liquor storage tank, and brine pump are connected in sequence through a conveying pipeline. The powder tank is connected to the cooling and stirring tank through a conveying pipeline. The cooling and stirring tank is connected to a filter through a conveying pipeline. The brine pump is connected to an ammonia absorption tower through a conveying pipeline.

7. A catalyst preparation system using underground coal gasification byproducts according to claim 6, characterized in that, The sodium chloride solution extraction device further includes a dryer and a first collection tank. The dryer is connected to a centrifuge via a conveying pipe, and the first collection tank is connected to the dryer via a conveying pipe.

8. A catalyst preparation system using underground coal gasification byproducts according to claim 1, characterized in that, The sodium bicarbonate solid processing device includes a calcining furnace and a carbon dioxide condenser connected in sequence by a conveying pipeline. The calcining furnace is connected to a filter via a conveying pipeline, and the carbon dioxide condenser is connected to a conveying pipeline between a carbon dioxide extraction device and a carbonization tower via a conveying pipeline.

9. A catalyst preparation system using underground coal gasification byproducts according to claim 8, characterized in that, The sodium bicarbonate solid treatment device also includes a wastewater treatment device, which is connected to a carbon dioxide condenser via a pipeline.

10. A catalyst preparation system using underground coal gasification byproducts according to claim 8, characterized in that, Also includes: The second collection tank, the catalyst injection device, and the pure water device are connected in sequence to the second collection tank, the catalyst injection device, and the injection well via a conveying pipeline. The pure water device is connected to the cooling and stirring tank, the catalyst injection device, and the conveying pipeline between the catalyst injection device and the injection well via a conveying pipeline.

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