Regeneration method of active coke

Abstract

The invention provides a regeneration method of active coke, regeneration is performed in an internal heat rotary regeneration furnace, the regeneration furnace is horizontally inclined downwards by 1.5-3 degrees, and a furnace chamber is sequentially divided into a feeding section, a pyrolysis section, an activation section and a discharging section; an internal heating type countercurrent regeneration method is adopted, and low-boiling-point organic matter is volatilized together with water vapor along with temperature rise in the drying process; during pyrolysis, most of the organic matters are pyrolyzed; during activation, the residual organic matters are pyrolyzed at a higher temperature, and the active coke recovers original pores, so that the active coke is regenerated; the pyrolysis flue gas is subjected to sufficient heat exchange with the materials; the volatilized organic gas can be fully combusted at the first time and can provide heat for regeneration, so that the organic gas is combusted to prevent deflagration and explosion; an activating agent water vapor does not need to be supplemented, and the volatilized water vapor is enough to generate an activation reaction; the safety coefficient is high, the service life of the equipment is long, the heat efficiency is high, and the operation is simple and convenient.

Description

Technical Field

[0001] The invention belongs to the technical field of activated coke regeneration, and in particular relates to a method for regenerating activated coke. Background Art

[0002] Activated coke is mainly made of coal. The production process of activated coke mainly includes several processes such as pulverization, batching, forming, coking, and activation of raw materials. Among them, the activation process is also a key step in forming a high specific surface area and pore structure of activated coke. The activation conditions of activated coke are more flexible, and parameters such as activation temperature and activation time can be adjusted according to actual needs to obtain ideal adsorption performance. The surface area of ​​activated coke is between coke and activated carbon. Although it is not as high as activated carbon, it can still meet the needs of most industrial applications. Although the pore structure of activated coke is not as developed as that of activated carbon, it has more types of surface groups and stable chemical properties, which makes it have unique advantages in certain specific fields (such as air pollution control and environmental water treatment). In addition, activated coke also has good thermal stability and renewability, and is suitable for long-term use in harsh environments such as high temperature and high humidity. Activated coke has broad application prospects in the fields of air pollution control and environmental water treatment due to its low cost, moderate specific surface area, stable chemical properties, and renewability. Activated coke can also be used to make high-end products such as catalyst carriers and electrode materials.

[0003] At present, the difficulties of activated coke regeneration are mainly as follows: the loss of activated coke during the regeneration process is large: during the regeneration process, the activated coke is prone to breakage and pulverization, resulting in increased losses; after regeneration, the adsorption capacity of activated coke decreases, and multiple regenerations are required to achieve the ideal adsorption effect; the tail gas generated during the regeneration process is likely to cause secondary pollution to the environment; the regeneration equipment is complex and costly: traditional regeneration equipment such as high-temperature converters or high-temperature multi-layer furnaces are complex to operate and require high regeneration fees; the regeneration process consumes a lot of energy, increasing operating costs. At present, the regeneration cost of activated coke is high, the safety factor is low, the production environment is dirty and poor, the investment is large, and the equipment life is short. Summary of the invention

[0004] The object of the present invention is to provide a method for regenerating activated coke.

[0005] In order to achieve the above object, the technical solution of the present invention is as follows:

[0006] An activated coke regeneration method, wherein the saturated activated coke is fed into an internal heat rotary regeneration furnace via a screw feeder for regeneration;

[0007] The internal heat rotary regeneration furnace is a horizontal furnace and is inclined downward by 1.5-3 degrees from the furnace head to the furnace tail;

[0008] A burner is provided at the furnace tail of the internal heat rotary regeneration furnace;

[0009] Impurities adsorbed in the spent activated coke are resolved at high temperatures and react with oxygen to produce water vapor and carbon dioxide gas that enter the flue gas;

[0010] The regenerated activated coke is deposited at the bottom of the internal heat rotary regeneration furnace and moves toward the furnace tail discharge port as the internal heat rotary regeneration furnace rotates to complete the regeneration process;

[0011] After the regeneration is completed, the activated coke is cooled in a closed water-cooled converter and then lifted to the dry material bin for storage by an elevator;

[0012] The internal heat countercurrent regeneration treatment is adopted. The high-temperature flue gas generated during the regeneration process flows in the opposite direction to the material under the suction of the exhaust fan, and the flue gas is discharged through the outlet of the burner. This process not only reduces the temperature of the flue gas, but also dries and heats the material, making full use of the heat energy.

[0013] The furnace chamber of the internal heat rotary regeneration furnace is divided into the feeding section, pyrolysis section, activation section and discharging section in sequence:

[0014] The saturated activated coke is kept in stock in the screw feeder to form a natural seal, isolating the furnace gas from the outside world;

[0015] The material is dried and preheated to 140℃-160℃ in the feeding section to discharge moisture and low-boiling organic matter;

[0016] In the pyrolysis stage, the material is further heated to 580℃-620℃, at which time the high-boiling-point organic matter further volatilizes, and the non-volatile organic residue remains in the activated coke in the form of fixed carbon;

[0017] In the activation stage, the material is heated to 830°C-870°C, at which point the material reacts with the remaining water vapor in the furnace to create micropores;

[0018] In the discharge section, the temperature is controlled at 700℃-750℃, and the material begins to cool down initially, preparing to enter the furnace tail discharge port for discharge.

[0019] Preferably, feeding: the saturated activated coke is first dehydrated by a microfilter, then falls into a belt conveyor through the bottom discharge port of a wet material bin, then is quantitatively transported to a screw feeder by the belt conveyor, and finally is transported by the screw feeder to an internal heat rotary regeneration furnace for regeneration; a water receiving trough is provided at the bottom of the belt conveyor to collect sewage seeping out during transportation to prevent sewage from flowing out.

[0020] Preferably, cooling and discharging: the activated coke after regeneration is passed through a closed conveying pipeline into a water-cooled converter for cooling, and after cooling, it is lifted to a dry material bin by a hoist, and when used, it is sent to an activated coke adsorption tank through a hydraulic conveying system.

[0021] Preferably, flue gas purification treatment: the flue gas includes smoke dust and nitrogen oxides, and the flue gas purification treatment realizes denitration, washing and dust removal of the flue gas;

[0022] The specific flue gas purification is as follows: the 200℃-300℃ flue gas discharged from the furnace outlet enters the SCR tower for denitrification, the flue gas after denitrification enters the desulfurization wet electrostatic precipitator integrated tower for desulfurization and dust removal, and the flue gas after desulfurization and dust removal is discharged through the chimney.

[0023] Preferably, the particle size of the spent activated coke is 4-10 mesh, the feed rate is 0.2-1.5 t / h, and the water content is 30wt%-55wt%.

[0024] Preferably, the rotation speed of the internal heat rotary regeneration furnace is 1-3 revolutions / min, and the gas pressure in the furnace is controlled to be a slightly negative pressure - (50Pa-80Pa).

[0025] This application has achieved the following beneficial technical effects:

[0026] The present application adopts an internal heat countercurrent regeneration method, the principle of which is that part of the low-boiling point organic matter adsorbed during the drying process evaporates together with water vapor as the temperature gradually increases; during the pyrolysis process, most of the organic matter is pyrolyzed; during the activation process, the remaining organic compounds are pyrolyzed at a higher temperature, and the activated coke restores its original porosity, thereby achieving the purpose of regenerating the activated coke.

[0027] The present application provides heat for the regeneration furnace at the furnace tail. There are multiple options for providing the heat source, and the preferred option is to burn natural gas.

[0028] During the design process of this application, the countercurrent regeneration method is selected. In this method, the directions of high-temperature flue gas and material are opposite. Therefore, the pyrolysis flue gas has fully exchanged heat with the material before coming out of the furnace head, which can ensure that the flue gas temperature is lower than 300°C. If the temperature of the flue gas is too high, it means that the heat loss is serious. Therefore, this design can further improve the thermal efficiency.

[0029] During the design process of this application, the adsorption saturated activated coke is brought into direct contact with the heat source, thereby improving the thermal efficiency and regeneration efficiency.

[0030] During the design process of this application, the organic gas volatilized from the adsorption-saturated activated coke in the internal heat rotary regeneration furnace can be fully burned at the first time. The full combustion of this organic gas can, on the one hand, provide part of the heat for the regeneration of the activated coke, and on the other hand, the organic gas contains flammable and explosive components. Burning the organic gas can prevent the risk of deflagration and explosion.

[0031] The method of the present application can realize a closed-loop circulation process from waste activated coke to regenerated activated coke and then to reuse.

[0032] The method of the present application can achieve zero emission. Waste activated coke does not need to be transferred. After the activated coke reaches a certain lifespan at the work station, that is, after the adsorption reaches saturation, it can be mechanically transported to the regeneration furnace for high-temperature regeneration. After cooling, it can be transported to the dry material bin for reuse.

[0033] The regeneration furnace of the present application is built around the adsorption pool using regenerated coke and is closed-loop connected to the feeding and discharging systems of the adsorption pool, which greatly reduces the transportation and storage costs and has considerable economic benefits.

[0034] In the process of regenerating activated coke, there is no need to add activator (water vapor) because the activated coke is in the internal heat rotary regeneration furnace, and the water vapor volatilized comes into contact with the material in a high temperature environment, and an activation reaction can occur at this time to achieve the purpose of regenerating the activated coke.

[0035] The present application constructs an internal heat rotary regeneration furnace, in which the position in contact with the material is refractory material, and the outside of the refractory material is steel. Therefore, the highly corrosive gas generated during the pyrolysis of the material will not cause harm to the internal heat rotary regeneration furnace, so the service life of this regeneration furnace is long.

[0036] The present application provides temperature sensors, negative pressure sensors and gas analyzers at corresponding positions in the internal heat rotary regeneration furnace. The entire system is controlled by PLC. Compared with the old process, it is easy to operate, safe and clean, requires less labor and has low labor intensity.

[0037] In summary, this activated coke regeneration system has a high safety factor, a long equipment service life, high thermal efficiency and easy operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic diagram of a process flow of a method for regenerating activated coke provided in an embodiment of the present application;

[0039] Figure 2 A schematic diagram of the structure of an activated coke regeneration system provided in an embodiment of the present application;

[0040] In the figure: 1 wet material bin, 2 belt conveyor, 3 feed bin, 4 screw feeder;

[0041] 5 internal heat rotary regeneration furnace, 501 settling feeding chamber, 502 combustion discharging chamber;

[0042] 6 natural gas burner, 7 water-cooled converter;

[0043] 8SCR tower, 9 exhaust fan, 10 desulfurization wet electrostatic precipitator integrated tower, 11 chimney. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] In the description of the present invention, it should be understood that the terms "center", "axial", "radial", "longitudinal", "lateral", "length", "width", "up", "down", "front", "back", "left", "right", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the pyrolysis device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0046] like Figure 1-2 As shown in the figure: wet material bin 1, belt conveyor 2, feed bin 3, screw feeder 4; internal heat rotary regeneration furnace 5, sedimentation feed chamber 501, combustion discharge chamber 502; natural gas burner 6, water-cooled converter 7; SCR tower 8, exhaust fan 9, desulfurization wet electrostatic precipitator integrated tower 10, chimney 11.

[0047] An activated coke regeneration method, wherein saturated activated coke (waste activated coke) is fed into an internal heat rotary regeneration furnace 5 via a screw feeder 4 for regeneration;

[0048] The internal heat rotary regeneration furnace 5 is a horizontal furnace and is inclined downward by 1.5-3 degrees from the furnace head to the furnace tail;

[0049] A burner is provided at the tail of the internal heat rotary regeneration furnace 5;

[0050] Impurities adsorbed in the spent activated coke are resolved at high temperatures and react with oxygen to produce water vapor and carbon dioxide gas that enter the flue gas;

[0051] The regenerated activated coke is deposited at the bottom of the internal heat rotary regeneration furnace 5, and moves toward the furnace tail discharge port as the internal heat rotary regeneration furnace 5 rotates to complete the regeneration process;

[0052] After the regeneration is completed, the activated coke is cooled in a closed water-cooled converter 7 and then lifted by a hoist to a finished dry material bin for storage;

[0053] The internal heat countercurrent regeneration process is adopted. The high-temperature flue gas generated during the regeneration process flows in the opposite direction to the material under the suction of the exhaust fan 9, and the flue gas is discharged through the gas outlet of the burner. This process not only reduces the temperature of the flue gas, but also dries and heats the material, so that the heat energy is fully utilized;

[0054] The furnace chamber of the internal heat rotary regeneration furnace 5 is divided into a feeding section, a pyrolysis section, an activation section and a discharging section in sequence:

[0055] The saturated activated coke is kept in a certain amount in the screw feeder 4 to form a natural seal, isolating the gas in the furnace from the outside;

[0056] The material is dried and preheated to 140℃-160℃ in the feeding section to discharge moisture and low-boiling organic matter;

[0057] In the pyrolysis stage, the material is further heated to 580℃-620℃, at which time the high-boiling-point organic matter further volatilizes, and the non-volatile organic residue remains in the activated coke in the form of fixed carbon;

[0058] In the activation stage, the material is heated to 830℃-870℃, at which time the material reacts with the remaining water vapor in the furnace to re-wash the cracking micropores;

[0059] In the discharge section, the temperature is controlled at 700℃-750℃, and the material begins to cool down initially, preparing to enter the furnace tail discharge port for discharge.

[0060] In one embodiment of the present application, the saturated activated coke is first dehydrated by a microfilter, then falls into the belt conveyor 2 through the bottom discharge port of the wet material bin 1, and then is quantitatively transported to the screw feeder 4 by the belt conveyor 2, and finally is transported by the screw feeder 4 to the internal heat rotary regeneration furnace 5 for regeneration; a water receiving trough is provided at the bottom of the belt conveyor 2 to collect sewage seeping during the transportation process to prevent the sewage from flowing out.

[0061] In one embodiment of the present application, cooling and discharging: the activated coke after regeneration is passed through a closed feed pipe into a water-cooled converter 7 for cooling, and after cooling, it is lifted to a finished dry material bin by a hoist, and when used, it is delivered to an activated coke adsorption tank via a hydraulic conveying system.

[0062] In one embodiment of the present application, flue gas purification treatment: the flue gas includes smoke dust and nitrogen oxides, and the flue gas purification treatment realizes denitration, washing and dust removal of the flue gas;

[0063] The flue gas purification is specifically as follows: the 200℃-300℃ flue gas discharged from the furnace outlet enters the SCR tower 8 for denitrification, the flue gas after denitrification enters the desulfurization wet electrostatic precipitator integrated tower 10 for desulfurization and dust removal, and the flue gas after desulfurization and dust removal is discharged through a 12-meter chimney 11.

[0064] In one embodiment of the present application, the particle size of the spent activated coke is 4-10 mesh, the feed rate is 0.2-1.5 t / h, and the water content is 30wt%-55wt%.

[0065] In one embodiment of the present application, the rotation speed of the internal heat rotary regeneration furnace 5 is 1-3 revolutions / min, and the gas pressure in the furnace is controlled to be a slightly negative pressure - (50Pa-80Pa).

[0066] In the present application, the general process flow of activated coke regeneration is as follows: in the adsorption tank, saturated activated coke (waste activated coke) is mechanically transferred to the wet material bin 1, and then transported to the feed bin 3 through the belt conveyor 2. A hydrophobic screw feeder 4 is arranged under the feed bin 3. After simple hydrophobicity, the activated coke is transported to the internal heat rotary regeneration furnace 5 under the action of the screw feeder 4. This internal heat rotary regeneration furnace 5 is installed with an inclination angle of 1.5°-3° and is rotating. For each rotation of the regeneration furnace, the material will move a relative distance toward the tail of the furnace. The material is divided into a feeding section, a pyrolysis section, an activation regeneration section and a discharging section in the regeneration furnace. The high-temperature regenerated activated coke can be transported to the dry material bin after being cooled by the water-cooled converter 7 for adsorption.

[0067] The methods and devices not described in detail in the present invention are all prior art and will not be described in detail.

[0068] In order to better understand the present invention, the present invention is further specifically described below through the following examples, but it should not be understood as a limitation of the present invention. Some non-essential improvements and adjustments made by technicians in this field based on the above invention content are also considered to fall within the protection scope of the present invention.

[0069] Example 1

[0070] A method for regenerating activated coke, wherein saturated activated coke is fed into an internal heat rotary regeneration furnace 5 via a screw feeder 4 for regeneration;

[0071] The internal heat rotary regeneration furnace 5 is a horizontal furnace and is inclined downward by 2.2 degrees from the furnace head to the furnace tail;

[0072] A burner is provided at the tail of the internal heat rotary regeneration furnace 5;

[0073] Impurities adsorbed in the spent activated coke are resolved at high temperatures and react with oxygen to produce water vapor and carbon dioxide gas that enter the flue gas;

[0074] The regenerated activated coke is deposited at the bottom of the internal heat rotary regeneration furnace 5, and moves toward the furnace tail discharge port as the internal heat rotary regeneration furnace 5 rotates to complete the regeneration process;

[0075] After the regeneration is completed, the activated coke is cooled in a closed water-cooled converter 7 and then lifted to a dry material bin for storage by a hoist;

[0076] The internal heat countercurrent regeneration treatment is adopted. The high-temperature flue gas generated during the regeneration process flows in the opposite direction to the material under the suction of the exhaust fan 9, and the flue gas is discharged through the gas outlet of the feed burner head. This process not only reduces the temperature of the flue gas, but also dries and heats the material, so that the heat energy is fully utilized;

[0077] The furnace chamber of the internal heat rotary regeneration furnace 5 is divided into a feeding section, a pyrolysis section, an activation section and a discharging section in sequence:

[0078] The saturated activated coke is kept in a certain amount in the screw feeder 4 to form a natural seal, isolating the gas in the furnace from the outside;

[0079] The material is dried and preheated to 140℃-145℃ in the feeding section to discharge moisture and low-boiling-point organic matter;

[0080] In the pyrolysis stage, the material is further heated to 590℃-600℃, at which time the high-boiling-point organic matter further volatilizes, and the non-volatile organic residue remains in the activated coke in the form of fixed carbon;

[0081] In the activation stage, the material is heated to 850℃-860℃, at which time the material reacts with the remaining water vapor in the furnace to re-wash the cracking micropores;

[0082] In the discharge section, the temperature is controlled at 700℃-710℃, and the material begins to cool down initially, preparing to enter the furnace tail discharge port for discharge;

[0083] Feeding: The saturated activated coke is first dehydrated by a microfilter, then falls into the belt conveyor 2 through the bottom discharge port of the wet material bin 1, and then quantitatively transported to the screw feeder 4 by the belt conveyor 2, and finally transported by the screw feeder 4 to the internal heat rotary regeneration furnace 5 for regeneration; a water receiving trough is provided at the bottom of the belt conveyor 2 to collect sewage seeping out during the transportation process to prevent sewage from flowing out;

[0084] Cooling and discharging: After the regeneration, the activated coke enters the water-cooled converter 7 through a closed conveying pipeline for cooling. After cooling, it is lifted to the finished dry material bin by a hoist and is sent to the activated coke adsorption tank through a hydraulic conveying system when in use;

[0085] Flue gas purification: Flue gas contains smoke and nitrogen oxides, and flue gas purification can achieve denitrification, washing and dust removal of flue gas;

[0086] The flue gas purification is as follows: the flue gas at 220℃-240℃ discharged from the furnace outlet enters the SCR tower 8 for denitration, and the flue gas after denitration enters the desulfurization wet electrostatic precipitator integrated tower 10 for desulfurization and dust removal, and the flue gas after desulfurization and dust removal is discharged through a 12-meter chimney 11;

[0087] The particle size of the spent activated coke is 5-8 mesh, the feed rate is 0.6-0.8 t / h, and the water content is 30wt%-35wt%;

[0088] The rotation speed of the internal heat rotary regeneration furnace 5 is 2 revolutions / min, and the gas pressure in the furnace is controlled to be a slightly negative pressure - (60Pa-80Pa).

[0089] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for regenerating activated coke, characterized in that: The saturated active coke is fed into the internal heat rotary regeneration furnace through a screw feeder for regeneration; The internal heat rotary regeneration furnace is a horizontal furnace and is inclined downward by 1.5-3 degrees from the furnace head to the furnace tail; A burner is provided at the furnace tail of the internal heat rotary regeneration furnace; Impurities adsorbed in the spent activated coke are resolved at high temperatures and react with oxygen to produce water vapor and carbon dioxide gas that enter the flue gas; The regenerated activated coke is deposited at the bottom of the internal heat rotary regeneration furnace and moves toward the furnace tail discharge port as the internal heat rotary regeneration furnace rotates to complete the regeneration process; After the regeneration is completed, the activated coke is cooled in a closed water-cooled converter and then lifted to the dry material bin for storage by an elevator; The internal heat countercurrent regeneration treatment is adopted. The high-temperature flue gas generated during the regeneration process flows in the opposite direction to the material under the suction of the exhaust fan, and the flue gas is discharged through the outlet of the burner. This process not only reduces the temperature of the flue gas, but also dries and heats the material, making full use of the heat energy. The furnace chamber of the internal heat rotary regeneration furnace is divided into the feeding section, pyrolysis section, activation section and discharging section in sequence: The saturated activated coke is kept in stock in the screw feeder to form a natural seal, isolating the furnace gas from the outside world; The material is dried and preheated to 140℃-160℃ in the feeding section to discharge moisture and low-boiling organic matter; In the pyrolysis stage, the material is further heated to 580℃-620℃, at which time the high-boiling-point organic matter further volatilizes, and the non-volatile organic residue remains in the activated coke in the form of fixed carbon; In the activation stage, the material is heated to 830°C-870°C, at which point the material reacts with the remaining water vapor in the furnace to create micropores; In the discharge section, the temperature is controlled at 700℃-750℃, and the material begins to cool down initially, preparing to enter the furnace tail discharge port for discharge.

2. The method for regenerating activated coke according to claim 1, characterized in that: Feeding: The saturated activated coke is first dehydrated by a microfilter, then falls into the belt conveyor through the bottom discharge port of the wet material bin, and then is quantitatively transported to the screw feeder by the belt conveyor, and finally transported by the screw feeder to the internal heat rotary regeneration furnace for regeneration; a water receiving trough is provided at the bottom of the belt conveyor to collect sewage seeping out during the transportation process to prevent sewage from flowing out.

3. The method for regenerating activated coke according to claim 1, characterized in that: Cooling and discharging: After the regeneration is completed, the activated coke enters the water-cooled converter through a closed conveying pipeline for cooling. After cooling, it is lifted to the dry material bin by the elevator. When used, it is sent to the activated coke adsorption tank through the hydraulic conveying system.

4. The method for regenerating activated coke according to claim 1, characterized in that: Flue gas purification: Flue gas contains smoke and nitrogen oxides, and flue gas purification can achieve denitrification, washing and dust removal of flue gas; The specific flue gas purification is as follows: the 200℃-300℃ flue gas discharged from the furnace outlet enters the SCR tower for denitrification, the flue gas after denitrification enters the desulfurization wet electrostatic precipitator integrated tower for desulfurization and dust removal, and the flue gas after desulfurization and dust removal is discharged through the chimney.

5. The method for regenerating activated coke according to claim 1, characterized in that: The particle size of the spent activated coke is 4-10 mesh, the feed rate is 0.2-1.5 t / h, and the water content is 30wt%-55wt%.

6. The method for regenerating activated coke according to claim 1, characterized in that: The rotation speed of the internal heat rotary regeneration furnace is 1-3 revolutions / min, and the gas pressure in the furnace is controlled to be a slightly negative pressure - (50Pa-80Pa).

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