Low-concentration chemical-physical coupling intelligent continuous porous carbon production method and system

Abstract

The invention provides a low-concentration chemical-physical coupling intelligent continuous porous carbon production method and system. The method comprises the following steps: pretreatment: crushing a carbon source to obtain a carbon precursor; carbonizing: heating and carbonizing the carbon precursor in a fluidized bed reactor to obtain a carbonized product; chemical activation: dipping the carbonized product in a chemical activator solution to obtain a chemical activated product, and drying the chemical activated product; physical activation: mixing a reaction gas and an inert gas as an activation gas, placing the chemical activation product in the activation gas, and performing gas activation at a preset temperature to obtain a physical activation product; and post-processing. By coupling chemical activation with physical activation, the concentration of a chemical activation reagent can be reduced, and the wastewater amount and the pollutant concentration after reaction are reduced by reducing the dosage of the reagent, so that the wastewater treatment process is simplified, the treatment agent and energy consumption is reduced, and the treatment cost is reduced.

Description

Technical Field

[0001] This application relates to the technical field of porous carbon material preparation, and particularly to a method and system for producing low-concentration chemically and physically coupled intelligent continuous porous carbon. Background Art

[0002] Porous carbon is a carbonaceous material containing a large number of pores. With its unique physical and chemical properties, it has broad application prospects in multiple fields. Its pore structure not only endows it with a huge specific surface area but also enables it to perform excellently in adsorption separation, catalysis, energy storage, and environmental protection. For example, in the field of adsorption separation, porous carbon can effectively separate gas mixtures and remove pollutants in water; in the field of catalysis, porous carbon can be used as a catalyst carrier to improve the activity and selectivity of the catalyst; in the field of energy storage, porous carbon is one of the ideal electrode materials for supercapacitors and lithium-ion batteries.

[0003] At present, the preparation technology of porous carbon materials has been relatively mature. Common preparation methods include the template method, chemical vapor deposition method, and solvothermal method, etc. These methods can precisely control the pore size, pore volume, and surface functional groups of porous carbon to meet the requirements of different application scenarios. Nevertheless, porous carbon materials still face some challenges in practical applications, such as high preparation costs, insufficient batch stability, and environmental impacts. Therefore, further optimizing its preparation process, reducing costs, improving stability, and reducing environmental impacts will be an important direction for future research and development of porous carbon materials.

[0004] In existing production methods, the activation method, blending polymer carbonization method, organic gel carbonization method, and template method are several commonly used ones. Although the activation method is easy to operate, the synthesized porous carbon material has a wide pore size distribution. Especially for the chemical activation method, the reagent consumption is large, usually reaching 3-5 times that of the precursor, and at the same time, a large amount of alkali-containing wastewater will be generated. In contrast, the template method can adjust the pore channels through the ordered structure of the template to obtain a porous carbon material with a regular and ordered pore structure and a narrow pore size distribution. However, when synthesizing the carbon material precursor by the organic gel carbonization method, the drying stage may cause the collapse of the pore structure. To avoid this phenomenon, it is usually necessary to combine the template method with the sol-gel method to synthesize porous carbon materials. And the blending polymer carbonization method also has some deficiencies, such as uneven pore size distribution and many closed pores. Given the limitations of a single method, current researchers often adopt a combination of multiple synthesis methods to obtain a porous carbon material with a stable and ordered pore structure.

[0005] Patent CN101973542A adopts the KOH secondary activation method, which can control the specific surface area, but the prepared specific surface area is only in the range of 1500-1800 m 2between 3000 m² / g. Patent CN102515145A achieves precise controllability when the specific surface area is below 3000 m² / g, but high-concentration KOH has high requirements for the corrosion resistance of equipment. 2 When it is below 3000 m² / g, it is precisely controllable, but high-concentration KOH has high requirements for the corrosion resistance of equipment. Summary of the Invention

[0006] The present application provides a low-concentration chemical-physical coupling intelligent continuous production method for porous carbon, which can be used to solve the technical problems that the specific surface area of porous carbon is difficult to control and the preparation conditions are too harsh.

[0007] The present application provides a low-concentration chemical-physical coupling intelligent continuous production method for porous carbon, and the method includes:

[0008] Pretreatment: including crushing the carbon source to 50 - 200 μm to obtain a carbon precursor;

[0009] Carbonization: including heating and carbonizing the carbon precursor in a fluidized bed reactor to obtain a carbonized product. Among them, the inert gas reacts with the carbon precursor to form a primary pore structure, and pre-carbonizes the carbon precursor to remove volatile organic compounds;

[0010] Chemical activation: including impregnating the carbonized product in a chemical activator solution and performing a drying treatment to obtain a chemically activated product;

[0011] Physical activation: including mixing a reaction gas and an inert gas as an activation gas, placing the chemically activated product in the activation gas, and performing gas activation at a preset temperature to obtain a physically activated product; wherein, the activation gas forms a pore structure by oxidative etching of the chemically activated product;

[0012] Post-treatment: including sequentially performing pickling, water washing, filtration, and drying on the physically activated product to obtain a porous carbon material.

[0013] Exemplarily, the pore diameter of micropores is less than 2 nanometers; the pore diameter of mesopores is greater than 2 nanometers; the pore diameter of macropores is greater than 50 nanometers.

[0014] The above primary pores can be micropores or mesopores, their morphologies are irregular and the distribution is relatively random, and the primary pore structure is the starting point for further physical / chemical activation.

[0015] Further, during the pretreatment process, biomass raw materials or synthetic polymer materials are used as carbon sources; among them, the biomass raw materials are made from vegetable raw materials, mineral raw materials, and synthetic resins; the vegetable raw materials include one or more of fibrous, starchy, and lignin; the fibrous materials include one or more of wood pulp, sawdust, coconut shells, rice husks, etc., and the starchy materials include one or more of grains, barnyard grass, corn, etc.; the mineral raw materials include one or more of coal, tar, petroleum asphalt, etc., and the synthetic resins include one or more of phenolic resins, polyacrylonitrile, etc.

[0016] Further, in the crushing process of the pretreatment, intelligent crushing and screening are adopted, using a combination of a double-roll crusher and a ball mill, and a combination of a vibrating screen and an air classifier to achieve particle size classification;

[0017] The roll gap of the double-roll crusher is dynamically adjusted by a hydraulic servo module, with an adjustment accuracy of ≤0.1 mm, and the temperature of the roll surface is monitored and linked to the cooling module;

[0018] Gradient crushing is carried out using a double-roll crusher, with the gap set at 10 - 15 mm, the range of the roll surface temperature ≤60°C, the proportion of the part with an outlet particle size >5 mm <10%, and the proportion of the part with an outlet particle size of 1 - 5 mm ≥85%; the ball mill uses zirconia gradient grinding media, where the grinding balls of Φ10 mm and Φ5 mm are filled in a volume ratio of 3:7 - 5:5, and is equipped with a nitrogen inert protection device, with a ball-to-material ratio of 2:1 - 4:1, and ground for 0.5 - 2 h; the ball mill is ground to 50 - 200 μm in a nitrogen environment; vibrating screening is carried out, and the coarse particle layer, i.e., the particle layer >0.425 mm, is returned to the ball mill for secondary crushing, and the medium particle layer, i.e., the particle layer range of 0.15 - 0.425 mm, enters the air classifier for fine treatment; during the air classification process, the cut-off particle size is set at 0.25 - 0.5 μm, the rotational speed of the classification wheel is 1500 - 2500 rpm, the initial speed is set at 8 m / s through wind speed PID adjustment, and adjusted by ±1.5 m / s according to the particle size feedback, and the particle size data is collected in real time to dynamically adjust the process parameters: when the particle size after grinding deviates from the target value by >5%: adjust the rotational speed of the ball mill by ±2 rpm or the grinding time by ±5 min.

[0019] Further, the inert gas is any one of nitrogen, argon, neon, krypton, and xenon.

[0020] Further, the pressure of the inert gas is normal pressure or slightly positive pressure, i.e., 1 - 1.5 atm.

[0021] Further, during the carbonization process, the inert gas is preheated to 500 - 700°C; the carbonization temperature is 500 - 1000°C, the heating rate is 2 - 15°C / min, the carbonization time is 1 - 3 hours, and the carbonization pressure is 0.1 - 0.25 MPa.

[0022] Further, the concentration of the chemical activator solution is 10 - 40 wt.%; the chemical activator is one or more of KOH, NaOH, Ca(OH)2, ZnCl2 or H3PO4, the mass ratio of the chemical activator to the carbonized product ranges from 0.2:1 to 1:1, the impregnation time is 6 - 24 hours, and after impregnation, it is dried at 100 - 150 °C;

[0023] Further, the mixing ratio of the reaction gas to the inert gas is 1:0.5 - 1:3; the reaction gas is one or more gases such as CO2, water vapor, ammonia, air, etc.

[0024] Further, the total input amount of the activation gas is 1 - 5 times the mass of the chemically activated product.

[0025] Further, physical activation includes low - temperature physical activation and high - temperature physical activation; the preset temperature includes a first preset temperature and a second preset temperature;

[0026] The first preset temperature under low - temperature physical activation is 500 - 700 °C, the heating rate is 2 - 15 °C / min, the activation time is 1 - 3 hours, and the activation pressure is 0.1 - 0.25 MPa; after low - temperature physical activation, the pore structure is enlarged to form a microporous structure;

[0027] The second preset temperature under high - temperature physical activation is 700 - 110 °C, the heating rate is 2 - 15 °C / min, the activation time is 1 - 3 hours, and the activation pressure is 0.1 - 0.25 MPa; after high - temperature physical activation, the microporous structure is enlarged to form a mesoporous and macroporous composite structure.

[0028] Further, pickling is carried out using hydrochloric acid or nitric acid solution, the acid concentration is 0.1 - 2 mol / L, and the pickling time is 2 - 6 hours.

[0029] Further, the drying of chemical activation and post - treatment adopts a multi - stage combination of microwave drying and hot - air circulation. The humidity sensor provides real - time feedback to adjust the drying time, and the moisture content is controlled < 2%, achieving efficient, low - loss pore collapse rate (< 5%) and precise drying. Traditional drying of porous carbon takes a long time and is prone to local overheating, resulting in pore structure collapse.

[0030] In the first drying stage, the drying time ranges from 20 - 40 min, the total microwave power is 4.8 kW, the microwave duty cycle is 80%, and hot air at 80 - 100 °C is simultaneously introduced into the drying chamber, with a wind speed of 1.5 - 2.5 m / s;

[0031] In the second drying stage, the drying time ranges from 10 - 30 min; the microwave is switched to pulse mode, the duty cycle is 60%, the power is reduced to 3.6 kW, and the hot - air temperature decreases from 80 - 100 °C to 50 - 70 °C at a rate of 3 °C every 2 - 5 min, and the wind speed is increased to 2.5 - 3.5 m / s;

[0032] In the third drying stage, the drying time ranges from 10 to 20 minutes; the microwave is turned off, and hot air is maintained at 40 - 50 °C for dehumidification.

[0033] Furthermore, after post - treatment, tail gas treatment is carried out, and the washing and absorption alkali solution is any one of NaOH solution, Ca(OH)₂ solution, Na₂CO₃ solution, and NH₃·H₂O.

[0034] Furthermore, the specific surface area of the porous carbon material is 800 - 2500 m 2 / g, the pore size distribution is 0.5 - 100 nm, and it has a hierarchical pore structure including micropores, mesopores, and macropores.

[0035] This application also provides a porous carbon production system device for low - concentration chemical - physical coupling intelligent continuous production, and the system is used to implement the method provided by this application.

[0036] The porous carbon production system device includes: a crushing device, an inert gas pre - heater, a static mixer, an activation gas pre - heater, a carbonization fluidized - bed reactor, an activation fluidized - bed reactor, a product collection tank, and a washing tower;

[0037] Among them, the crushing device is used to crush the carbon source to obtain a carbon precursor;

[0038] The inert gas pre - heater is used to pre - heat the inert gas; the activation gas pre - heater is used to pre - heat the activation gas;

[0039] The static mixer is used to mix the inert gas and the activation gas;

[0040] The carbonization fluidized - bed reactor is used to carry out carbonization reaction on the carbon precursor to obtain a carbonized product;

[0041] The activation fluidized - bed reactor is used to carry out activation reaction on the carbonized product to obtain an activated product;

[0042] The product collection tank is used to collect the porous carbon material;

[0043] The washing tower is used to purify the dust in the gas;

[0044] The outlet of the inert gas pre - heater and the outlet of the activation gas pre - heater are connected to the static mixer;

[0045] The outlet of the crushing device and the outlet of the static mixer are both connected to the carbonization fluidized - bed reactor;

[0046] The material outlet of the carbonization fluidized - bed reactor is connected to the material inlet of the activation fluidized - bed reactor; the material outlet of the activation fluidized - bed reactor is connected to the material inlet of the product collection tank; the gas outlet of the activation fluidized - bed reactor is connected to the washing tower.

[0047] Furthermore, the carbonization fluidized bed reactor and the activation fluidized bed reactor can be the same fluidized bed reactor.

[0048] Furthermore, the fluidized bed reactor is used for carbonizing and activating carbon powder to obtain the reaction product porous carbon, which not only ensures sufficient mixing between the gas-solid raw materials, but also performs good grading on the target porous carbon, timely separates and collects the target product to avoid its complete consumption due to over-activation, and realizes the cyclic activation of raw material particles and precise control of the activation reaction time. The fluidized bed reactor is provided with multiple on-line pressure measurement points and temperature measurement points to monitor the operating state of the fluidized bed in real time. Previously, the production of porous carbon mostly adopted the form of rotary kiln activation. Due to the fluctuations of parameters such as temperature and atmosphere in the rotary furnace, the quality of the porous carbon material was unstable.

[0049] Furthermore, the gas feeding of the fluidized bed reactor adopts staged feeding to improve the gas-solid mass transfer efficiency; a self-cleaning filter device is arranged at the gas outlet, including pulse backwashing. The compressed air is instantaneously blown back in the reverse direction to shake off the dust on the surface of the filter material. The filter element is made of metal fiber, ceramic or PTFE-coated filter bag, etc., and the filtration accuracy is 10-25μm. The automatic start-stop cleaning program is realized through a differential pressure sensor; induction heating is adopted, and the temperature in the fluidized bed is monitored in real time to adjust the heating power; nitrogen nozzles are arranged in a ring at the material outlet to prevent material blockage.

[0050] Furthermore, the heating method of the fluidized bed reactor is induction heating, and multi-stage temperature measurement and temperature feedback are adopted to adjust the heating power in real time to meet the stable temperature operating environment and the operating conditions of low-temperature activation and high-temperature activation in the technical solution. Pressure sensors are arranged in the carbonization fluidized bed and the activation fluidized bed. When the pressure of the fluidized bed exceeds the set safety pressure range, the valve of the pressure relief pipeline is adjusted to meet the safe operation, and the feeding system is synchronously interlocked and cut off to ensure the stability of the fluidization process and the integrity of the equipment.

[0051] Furthermore, a laser on-line porosity detector is arranged in the carbonization fluidized bed reactor and the activation fluidized bed reactor; the laser on-line porosity detector is used to feedback the porosity of the porous carbon. According to the porosity data monitored in real time, it is compared with the set target porosity range to adjust the activation time. Through real-time feedback adjustment, it is ensured that the porosity of the porous carbon material is always within the target range, improving the product quality and consistency; the target porosity of the laser on-line porosity detector in the activation fluidized bed reactor is 80% - 90%; when the porosity is lower than the target porosity, one or more of the following measures are taken: reducing the heating rate, extending the activation time, increasing the activation gas flow rate, and adjusting the pressure of the activation fluidized bed reactor.

[0052] Furthermore, a filter is provided at the gas outlet of the product collection tank to prevent the gas from entraining reaction raw materials; a filter is also provided at the gas outlet of the carbonization fluidized bed reactor. The carbon powder entrained in the outlet gas is retained in the fluidized bed by the filter, reducing the loss of products in the process flow.

[0053] Furthermore, the system also includes a waste heat recovery heat exchanger for tail gas. The outlet of the waste heat recovery heat exchanger for tail gas is connected to an inert gas preheater and a fluidized bed reactor. The heat in the waste heat recovery heat exchanger for tail gas is used to heat the inert gas and provide the heat required for the reaction temperature of the fluidized bed reactor. The tail gas is subjected to heat recovery in the waste heat recovery heat exchanger for tail gas to preheat the inert gas, and then purified by a multi-stage scrubbing tower after cooling. The whole process integrates overpressure / overtemperature interlock protection and dynamic matrix closed-loop control of gas flow, achieving efficient, stable, and low-consumption production.

[0054] Furthermore, the scrubbing tower is of a multi-stage type, including an absorption section, a spraying section, and a drying section, and part of the scrubbing liquid is returned for reuse.

[0055] Furthermore, the system also includes an integrated overpressure and overtemperature safety interlock protection module. For the coordinated feeding of inert gas and reactive gas, flow ratio control is adopted. Based on the closed-loop control loop composed of a mass flow controller and a regulating valve, according to the preset ratio parameters, precise matching of multi-branch flows is achieved through the dynamic matrix control algorithm, and the feeding amounts of inert gas and activation gas are automatically adjusted. The control module collects the flow signals of each branch in real time, outputs a pulse width modulation signal through PID operation to drive an intelligent positioner, and realizes the non-linear compensation control of the opening of the regulating valve.

[0056] Furthermore, for the inert gas preheater and the waste heat recovery heat exchanger for tail gas, a jacketed or shell-and-tube heat exchange structure is adopted. The outlet temperature of the material is automatically changed by adjusting the valve position stroke of the circulating water and circulating steam regulating valves to maintain the outlet temperature within the range of set value ±2°C; when the outlet temperature of the inert gas preheater is lower than the set temperature, the amount of circulating steam is increased; when the outlet tail gas temperature of the waste heat recovery heat exchanger for tail gas is higher than the set temperature, the amount of circulating cooling water used is increased.

[0057] Furthermore, if the carbonization fluidized bed reactor and the activation fluidized bed reactor are shared, the investment in process equipment is reduced.

[0058] Furthermore, the crushing device adopts intelligent crushing and screening technology: after the carbon source is coarsely crushed in a gradient manner by a double-roll crusher, it is refined to 50-200 μm by a ball mill in combination; after vibrating screening, the coarse particles (>0.425 mm) are returned to the ball mill, and the medium particles (0.15-0.425 mm) are accurately regulated in particle size by air classification, and the ball mill parameters are dynamically adjusted by real-time feedback data. The carbon precursor is transported to the fluidized bed reactor by an inert gas, carbonized in the inert gas to form primary pores and remove VOCs; the carbonized product is dried after chemical impregnation, and then enters the fluidized bed reactor for staged physical activation: low-temperature activation etching generates micropores, and high-temperature activation expands to a mesoporous-macroporous composite structure.

[0059] Furthermore, the fluidized bed reactor adopts induction heating multi-stage temperature control, staged feeding and self-cleaning filtration, and combines laser online porosity detection to real-time regulate activation parameters including time, heating rate, gas flow rate and pressure to ensure a porosity of 80%-90%.

[0060] Furthermore, after the activated product is pickled and washed with water until neutral, it is dried by microwave-hot air in multiple stages, and finally the moisture content is <2% and the pore collapse rate is <5%.

[0061] Compared with the prior art, the present invention has the following advantages:

[0062] (1) In the present invention patent, the carbon raw material is pretreated in the early stage, the concentration of the chemical activation reagent is reduced, the reagent dosage is reduced, so that the wastewater volume and pollutant concentration after the reaction are reduced, the wastewater treatment process is simplified, the treatment chemicals and energy consumption are reduced, and the treatment cost is lowered.

[0063] (2) The present invention patent uses a combination of a double-roll crusher and a ball mill, and a combination of a vibrating screen and an air classifier to solve the problem of wide particle size distribution in traditional single-stage crushing. The carbonization fluidized bed reactor and the activation fluidized bed reactor are shared, reducing the investment in process equipment.

[0064] (3) In the process flow of the present invention patent, the tail gas generated is used for preheating the inert gas required in the carbonization and activation stages through waste heat recovery, converting the "waste heat" into valuable energy, generating steam with the reaction waste heat to preheat the gas, and realizing an energy closed-loop.

[0065] (4) Reducing the concentration of the chemical activation reagent in the present invention patent can, while ensuring the activation effect, retain the main structure of the carbon material, prevent over-corrosion, maintain the integrity of the material, and prevent corrosion of the reactor; using a low-concentration reagent is easy to combine with physical activation to achieve a synergistic effect, optimize the porous carbon structure and performance, and meet different application requirements.

[0066] (5) This invention patent can achieve continuous production of porous carbon, enabling continuous input of raw materials and continuous output of products. It adopts intelligent on-line porosity detection to monitor the change of porosity of porous carbon materials in real time, and optimizes the activation process through a feedback regulation mechanism, improving production efficiency and the batch stability of porous carbon products.

[0067] (6) A fluidized bed reactor is used for carbonization and activation reactions to obtain the reaction product porous carbon. It not only ensures sufficient mixing between gas-solid raw materials but also performs good classification on the target porous carbon, timely separating and collecting the target product to avoid its complete consumption due to over-activation, and realizing the cyclic activation of raw material particles and precise control of the activation reaction time. Description of the Drawings

[0068] Figure 1 Schematic diagram of a low-concentration chemical-physical coupling intelligent continuous porous carbon production system in Example 1;

[0069] Figure 2 Schematic diagram of a low-concentration chemical-physical coupling intelligent continuous porous carbon production system in Example 2;

[0070] Figure 3 Cross-sectional view of the structure of the fluidized bed reactor according to an embodiment of the present application;

[0071] Figure 4 Flowchart of the low-concentration chemical-physical coupling intelligent continuous porous carbon production method according to an embodiment of the present application;

[0072] Figure 1 、 2 Explanation of the markings in Figures 1, 2, and 3: 1 - Inert gas preheater, 2 - Static mixer, 3 - Activation gas preheater, 4 - Carbon powder raw material tank, 5 - First fluidized bed reactor, 6 - Carbon precursor collection tank, 7 - Pretreated carbon precursor raw material tank, 8 - Second fluidized bed reactor, 9 - Product collection tank, 10 - Filter, 11 - Tail gas waste heat recovery heat exchanger, 12 - Scrubber, 13 - Carbon powder recovery tank; 14 - Gas outlet, 15 - Temperature measurement port, 16 - Gas inlet, 17 - Material outlet, 18 - Induction heater. Detailed Embodiments

[0073] To make the objectives, technical solutions, and advantages of the present application clearer, the following will further describe the embodiments of the present application in detail with reference to the accompanying drawings.

[0074] In the present application, by optimizing the activation sequence and parameters, the directional regulation and stable continuous production of the pores of porous carbon are achieved. At the same time, the usage and concentration of chemical reagents are reduced, the waste liquid discharge is decreased, and the product performance and process environmental friendliness are improved.

[0075] The objectives of the present invention can be achieved through the following technical solutions:

[0076] As Figure 1 shown, a low-concentration chemical-physical coupling intelligent continuous porous carbon production system includes an inert gas preheater 1, a static mixer 2, an activation gas preheater 3, a carbon powder raw material tank 4, a first fluidized bed reactor 5, a carbon precursor collection tank 6, a pretreated carbon precursor raw material tank 7, a second fluidized bed reactor 8, a product collection tank 9, a filter 10, a tail gas waste heat recovery heat exchanger 11, a scrubber 12, and a carbon powder recovery tank 13, which are sequentially connected along the material flow direction.

[0077] The content of this application will be specifically described below in conjunction with specific embodiments.

[0078] Example 1

[0079] The carbon powder material is crushed into uniform particles by using a combination of a double-roll crusher and a ball mill. A vibrating screen and an air classifier are combined to screen the carbon powder material. The purpose of this step is to ensure the uniformity and efficiency of the subsequent activation reaction, and the target particle size is 150 μm. The gap of the double-roll crusher is set to 10 mm, the roll temperature is monitored ≤ 60 °C, the ball-to-material ratio of the ball mill is 2:1, and the filling rate is 35%. It is ground for 1 h under nitrogen protection (oxygen content < 100 ppm). The cutting particle size of the air classifier is set to 0.25 μm, and the rotational speed of the classification wheel is 1750 rpm.

[0080] The carbon precursor is transported from the carbon powder raw material tank 4 to the first fluidized bed reactor 5 by inert gas. In this example, the first fluidized bed reactor 5 is a carbonization fluidized bed reactor. It is carbonized at high temperature by inert gas to remove volatile organic compounds and some impurities in the carbon precursor, providing a relatively pure carbon matrix for the subsequent activation reaction. The inert gas is preheated to 500 °C by the preheater 1 and carbonized at 800 °C for 3 h under a pressure of 0.13 MPa. After carbonization, it is transported to the carbon precursor collection tank 6 by gas. KOH and carbon are mixed at a mass ratio of 0.2:1, and the concentration of the KOH solution is 15 wt.%. The carbon precursor after carbonization is mixed and impregnated with the KOH solution for 24 h and dried at 100 °C. The impregnated and dried carbon material is transported from the pretreated carbon powder raw material tank 7 to the second fluidized bed reactor 8 by inert gas. In this example, the second fluidized bed reactor 8 is an activation fluidized bed reactor, and the activation reaction is carried out under high temperature and inert gas protection. The activation gas H2O and the inert gas are mixed at a ratio of 0.5:1 and preheated to 300 °C in the activation gas preheater 3. The activation reaction is carried out in stages, including low-temperature activation and high-temperature activation. During this process, the activator reacts chemically with the carbon material to etch the carbon material to form a pore structure. The low-temperature activation temperature is 400 °C, and the activation time is 4 h under a pressure of 0.15 MPa. The high-temperature activation temperature is 900 °C, and the activation time is 4 h under a pressure of 0.15 MPa.

[0081] After the reaction is completed, the porous carbon material is transported to the product collection tank 9 through gas. After carbonization and activation, the gas passes through the filter 10 to remove dust in the gas, and the dust is collected in the carbon powder recovery tank 13. The tail gas is cooled to 50 °C by the tail gas waste heat recovery heat exchanger 11, and the acidic gas in the gas is removed through the scrubber 12. The heat generated by the tail gas waste heat recovery heat exchanger 11 is used to heat steam for preheating the inert gas preheater 1. The porous carbon product is washed with hydrochloric acid and hot water to remove the salts and other impurities generated by the reaction. Then the washed carbon material is dried to remove moisture. Drying stage 1: The total microwave power is 4.8 kW, the microwave duty cycle is 80%, hot air at 80 °C is introduced into the drying chamber synchronously, the wind speed is 2.5 m / s, and the drying duration is 40 min; Drying stage 2: The microwave is switched to the pulse mode (duty cycle 60%), the power is reduced to 3.6 kW, the hot air temperature decreases at a rate of 3 °C every 3 min until it reaches 60 °C, the wind speed is increased to 3 m / s, and the drying duration is 30 min; Drying stage 3: The microwave subsystem is turned off, the hot air temperature is maintained at 50 °C and the dehumidification module is started until the moisture content of the material < 2%.

[0082] Example 2

[0083] As Figure 2 shown, a low-concentration chemical-physical coupling intelligent continuous porous carbon production system. Compared with Example 1, the difference is that this example only includes the first fluidized bed reactor 5. It should be noted that in this example, the first fluidized bed reactor performs two reactions, namely carbonization and activation, that is, the carbonization fluidized bed reactor and the activation fluidized bed reactor are shared, reducing the investment in process equipment. The carbon powder raw material tank and the pre-treated carbon precursor raw material tank are shared, and the carbon precursor collection tank and the product collection tank are shared; and in this example, the filter is set at the gas outlet of the fluidized bed reactor and the product collection tank, and the carbon powder entrained in the outlet gas is retained in the fluidized bed through the filter, reducing the loss of the product in the process. The rest of the system is the same as in Example 1.

[0084] The carbon powder material is crushed into uniform particles and screened, with a target particle size of 100 μm. The reaction raw materials are transported from the carbon powder raw material tank 4 to the first fluidized bed reactor 5 by inert gas, and carbonized at high temperature by inert gas to remove volatile organic compounds and some impurities in the raw materials, providing a relatively pure carbon matrix for the subsequent activation reaction. The inert gas is preheated to 500 °C by the inert gas preheater 1, carbonized at 900 °C for 3 h under a pressure of 0.16 MPa. After carbonization, it is transported by gas to the carbon precursor collection tank 6; ZnCl2 and carbon are mixed at a mass ratio of 0.5:1, and the concentration of the ZnCl2 solution is 30 wt.%. The carbon precursor after carbonization is mixed and impregnated with the ZnCl2 solution for 16 h and dried at 150 °C. The impregnated and dried material is transported from the carbon powder raw material tank 4 to the first fluidized bed reactor 5 by inert gas for activation reaction under high temperature and inert gas protection. The activation gas air / H2O and inert gas are mixed at a ratio of 1:1 and preheated to 350 °C in the activation gas preheater 3. The activation reaction is carried out in stages, divided into low-temperature activation and high-temperature activation. During this process, the activator chemically reacts with the carbon material to etch the carbon material to form a pore structure. The low-temperature activation temperature is 500 °C, activated for 3 h, pressure 0.15 MPa, and the activation gas is a mixed gas of air and inert gas; the high-temperature activation temperature is 1000 °C, activated for 3 h, pressure 0.15 MPa, and the activation gas is a mixed gas of H2O and inert gas.

[0085] After the reaction ends, the porous carbon product is transported by gas to the product collection tank 9, and the gas after carbonization and activation passes through the filter 10 to remove dust in the gas. The tail gas is cooled to 50 °C by the tail gas waste heat recovery heat exchanger 11, and the acidic gas in the gas is removed through the scrubber. The heat generated by the tail gas waste heat recovery heat exchanger 11 is used to heat steam for preheating the inert gas preheater 1. The carbon material is washed with hydrochloric acid and hot water to remove salts and other impurities generated by the reaction. Then the washed carbon material is dried at 150 °C to remove moisture. Drying stage 1: The total microwave power is 4.8 kW, the microwave duty cycle is 80%, and hot air at 90 °C is introduced into the drying chamber synchronously at a wind speed of 2 m / s for a drying duration of 30 min; Drying stage 2: The microwave is switched to the pulse mode (duty cycle 60%), the power is reduced to 3.6 kW, the hot air temperature decreases at a rate of 3 °C every 4 min, the temperature is reduced to 70 °C, the wind speed is increased to 3.5 m / s, and the drying duration is 25 min; Drying stage 3: The microwave subsystem is turned off, the hot air temperature is maintained at 45 °C and the dehumidification module is started until the moisture content of the material < 2%.

[0086] Example 3

[0087] Using the same system as in Example 2, the toner material is crushed into uniform particles and screened, with a target particle size of 200 μm. The reaction raw materials are transported from the toner raw material tank 4 to the first fluidized bed reactor 5 by inert gas and carbonized at high temperature by inert gas to remove volatile organic compounds and some impurities in the raw materials, providing a relatively pure carbon matrix for the subsequent activation reaction. The inert gas is preheated to 500 °C by the preheater 1 and carbonized at 1000 °C for 3 h under a pressure of 0.17 MPa. After carbonization, it is transported by gas to the carbon precursor collection tank 6; NaOH and carbon are mixed at a mass ratio of 0.4:1, and the concentration of the NaOH solution is 20 wt.%. The carbonized carbon precursor is mixed and impregnated with the NaOH solution for 24 h and dried at 100 °C. The impregnated and dried carbon material is transported from the pretreated toner raw material tank 7 to the first fluidized bed reactor 5 by inert gas and undergoes an activation reaction under high temperature and inert gas protection. The activation gas air / H2O and inert gas are mixed at a ratio of 1:2 and activated in sequence, and preheated to 300 °C in the activation gas preheater 3. The activation reaction is carried out in stages, divided into low-temperature activation and high-temperature activation. During this process, the activator reacts chemically with the carbon material to etch the carbon material to form a pore structure. The low-temperature activation temperature is 400 °C, activated for 3.5 h, under a pressure of 0.2 MPa, and the activation gas is a mixed gas of CO2 and inert gas; the high-temperature activation temperature is 900 °C, activated for 3.5 h, under a pressure of 0.2 MPa, and the activation gas is a mixed gas of H2O and inert gas.

[0088] After the reaction ends, the porous carbon product is transported by gas to the product collection tank 9. The gases after carbonization and activation pass through the filter 10 to remove dust in the gas, and the dust is collected in the toner recovery tank 13. The tail gas is cooled to 50 °C by the tail gas waste heat recovery heat exchanger 11, and the acidic gas in the gas is removed through the scrubber. The heat of the tail gas waste heat recovery heat exchanger 11 is used to heat steam for preheating the inert gas preheater 1. The carbon material is washed with hydrochloric acid and hot water to remove salts and other impurities generated by the reaction. Then the washed carbon material is dried at 100 °C to remove moisture. Drying stage 1: The total microwave power is 4.8 kW, the microwave duty cycle is 80%, and hot air at 100 °C is simultaneously introduced into the drying chamber at a wind speed of 1.5 m / s for a drying duration of 35 min; Drying stage 2: The microwave is switched to the pulse mode (duty cycle 60%), the power is reduced to 3.6 kW, the hot air temperature decreases at a rate of 3 °C every 5 min, the temperature is reduced to 60 °C, the wind speed is increased to 3.5 m / s, and the drying duration is 20 min; Drying stage 3: The microwave subsystem is turned off, the hot air temperature is maintained at 40 °C, and the dehumidification module is started until the moisture content of the material < 2%.

[0089] Example 4

[0090] According to the same process system as in Example 1, compared with the example, a coupling of high-concentration chemical activation and physical activation is adopted. The carbon powder material is crushed into uniform particles and screened, with a target particle size of 150 μm. The reaction raw materials are transported from the carbon powder raw material tank 4 to the first fluidized bed reactor 5 by inert gas, and carbonized at high temperature by inert gas. The inert gas is preheated to 500 °C by the preheater 1 and carbonized at 750 °C for 3 h under a pressure of 0.145 MPa. After carbonization, it is transported to the carbon precursor collection tank 6 by gas. Chemical activation is carried out by impregnation with a high-concentration KOH solution. NaOH and carbon are mixed at a mass ratio of 3:1, and the concentration of the NaOH solution is 40 wt.%. The carbon precursor after carbonization is mixed with the KOH solution and impregnated for 24 h, and then dried at 100 °C. The impregnated and dried material is transported from the pretreated carbon powder raw material tank 7 to the second fluidized bed reactor 8 by inert gas for the activation reaction under high temperature and inert gas protection. The activation gas CO2 and the inert gas are mixed at a ratio of 1:3 and preheated to 300 °C in the activation gas preheater 3. The activation reaction is carried out in stages, divided into low-temperature activation and high-temperature activation. During this process, the activator reacts chemically with the carbon material to etch the carbon material to form a pore structure. The low-temperature activation temperature is 400 °C, the activation time is 2 h, and the pressure is 0.12 MPa.; the high-temperature activation temperature is 900 °C, the activation time is 2 h, and the pressure is 0.12 MPa..

[0091] After the reaction is completed, the porous carbon product is transported to the product collection tank 9 by gas. The gas after carbonization and activation passes through the filter 10 to remove dust in the gas, and the dust is collected in the carbon powder recovery tank 13. The tail gas is cooled to 50 °C by the tail gas waste heat recovery heat exchanger 11, and the acidic gas in the gas is removed through the scrubber. The carbon material is washed with acid (such as hydrochloric acid) and hot water to remove the salts and other impurities generated by the reaction. Then the washed carbon material is dried at 80 °C to remove moisture. Drying stage 1: The total microwave power is 4.8 kW, the microwave duty cycle is 80%, hot air at 95 °C is simultaneously introduced into the drying cavity at a wind speed of 2 m / s, and the drying duration is 30 min; Drying stage 2: The microwave is switched to the pulse mode (duty cycle 60%), the power is reduced to 3.6 kW, the hot air temperature decreases at a rate of 3 °C every 2 min, the temperature drops to 65 °C, the wind speed is increased to 3 m / s, and the drying duration is 30 min; Drying stage 3: The microwave subsystem is turned off, the hot air temperature is maintained at 50 °C and the dehumidification module is started until the moisture content of the material < 2%.

[0092] Comparative Example 1

[0093] According to the same process system as in Example 2, compared with the example, only physical activation production is adopted. The carbon powder material is crushed into uniform particles and screened, with a target particle size of 100 μm. The reaction raw materials are transported from the carbon powder raw material tank 4 to the first fluidized bed reactor 5 by inert gas and carbonized at high temperature by inert gas. The inert gas is preheated to 400 °C by the preheater 1 and carbonized at 600 °C for 4 h under a pressure of 0.189 MPa. The activation gas air / ammonia is mixed with the inert gas in a ratio of 1:2 and preheated to 350 °C in the activation gas preheater 3. The activation reaction is carried out in stages, divided into low-temperature activation and high-temperature activation. The low-temperature activation temperature is 500 °C, activated for 4 h, and the pressure is 0.17 MPa. The activation gas is a mixed gas of ammonia and inert gas; the high-temperature activation temperature is 1000 °C, activated for 4 h, and the pressure is 0.16 MPa. The activation gas is a mixed gas of air and inert gas. After the reaction, the porous carbon product is transported to the product collection tank 9 by gas, and the gas after carbonization and activation passes through the filter 10 to remove dust in the gas. The tail gas is cooled to 50 °C by the tail gas waste heat recovery heat exchanger 11, and the acidic gas in the gas is removed through the scrubber. The carbon material is washed with acid (such as hydrochloric acid) and hot water to remove the salts and other impurities generated by the reaction. Then the washed carbon material is dried at 90 °C to remove moisture. Drying stage 1: The total microwave power is 4.8 kW, the microwave duty cycle is 80%, and hot air at 80 °C is simultaneously introduced into the drying chamber at a wind speed of 2.5 m / s for a drying duration of 40 min; Drying stage 2: The microwave is switched to the pulse mode (duty cycle 60%), the power is reduced to 3.6 kW, the hot air temperature decreases at a rate of 3 °C every 3 min to 60 °C, the wind speed is increased to 3 m / s, and the drying duration is 30 min; Drying stage 3: The microwave subsystem is turned off, the hot air temperature is maintained at 50 °C, and the dehumidification module is started until the moisture content of the material < 2%.

[0094] Comparative Example 2

[0095] According to the same process system as in Example 2, compared with the example, only high-concentration chemical activation production is adopted. The carbon powder material is crushed into uniform particles and screened, with a target particle size of 200 μm. The reaction raw materials are transported from the carbon powder raw material tank 4 to the first fluidized bed reactor 5 by inert gas, and are carbonized at high temperature by inert gas to remove volatile organic compounds and some impurities in the raw materials, providing a relatively pure carbon matrix for the subsequent activation reaction. The inert gas is preheated to 500 °C by the preheater 1, carbonized at 900 °C for 4 h, and the pressure is 0.16 MPa. After carbonization, it is transported by gas to the carbon precursor collection tank 6; KOH and carbon are mixed at a mass ratio of 2:1, and the concentration of the KOH solution is 25 wt.%. The carbon precursor after carbonization is mixed and impregnated with the KOH solution for 24 h and dried at 100 °C. The impregnated and dried carbon material is transported from the pretreated carbon powder raw material tank 7 to the fluidized bed reactor 5 by inert gas and undergoes an activation reaction under inert gas. The inert gas is preheated to 300 °C in the preheater 1. The activation temperature is 950 °C, the activation time is 2 h, the pressure is 0.21 MPa, and the activation gas is inert gas.

[0096] After the reaction is completed, the porous carbon product is transported by gas to the product collection tank 9. The gas after carbonization and activation passes through the filter 10 to remove dust in the gas, and the dust is collected in the carbon powder recovery tank 13. The tail gas is cooled to 50 °C by the tail gas waste heat recovery heat exchanger 11, and the acidic gas in the gas is removed through the scrubber. The heat of the waste heat recovery heat exchanger heats the steam, which is used to preheat the inert gas preheater 1. The carbon material is washed with hydrochloric acid and hot water to remove the salts and other impurities generated by the reaction. Then the washed carbon material is dried at 100 °C to remove moisture. Drying stage 1: The total microwave power is 4.8 kW, the microwave duty cycle is 80%, hot air at 90 °C is simultaneously introduced into the drying chamber, the wind speed is 2 m / s, and the drying duration is 30 min; Drying stage 2: The microwave is switched to the pulse mode (duty cycle 60%), the power is reduced to 3.6 kW, the hot air temperature decreases at a rate of 3 °C every 4 min, the temperature is reduced to 70 °C, the wind speed is increased to 3.5 m / s, and the drying duration is 25 min; Drying stage 3: The microwave subsystem is turned off, the hot air temperature is maintained at 45 °C and the dehumidification module is started until the moisture content of the material < 2%.

[0097] An automatic specific surface area and porosity analyzer is used to perform nitrogen adsorption and desorption tests on the samples at a temperature of 77 K and a pressure of 1 bar, draw the adsorption and desorption isotherms, and analyze the specific surface area and pore volume.

[0098] Table 1: Comparison table of implementation conditions

[0099]

[0100] The nitrogen adsorption and desorption data of different batches of porous carbon materials are compared, and statistical parameters such as the mean value, standard deviation, and coefficient of variation are calculated to evaluate the consistency and stability between batches.

[0101] Table 2: Specific Surface Area and Pore Volume Test Table

[0102]

[0103]

[0104] The embodiments of the present application described above do not constitute a limitation on the protection scope of the present application.

Claims

1. A production method of porous carbon with low-concentration chemical-physical coupling and intelligent continuity, characterized in that, The method includes the following steps: Pretreatment: including crushing the carbon source to 50 - 200 μm to obtain a carbon precursor; Carbonization: including heating and carbonizing the carbon precursor in a fluidized bed reactor to obtain a carbonized product. Among them, the inert gas reacts with the carbon precursor to form a primary pore structure, and pre - carbonizes the carbon precursor to remove volatile organic compounds; Chemical activation: including impregnating the carbonized product in a chemical activator solution and performing a drying treatment to obtain a chemically activated product; Physical activation: including mixing a reaction gas and an inert gas as an activation gas, placing the chemically activated product in the activation gas, and performing gas activation at a preset temperature to obtain a physically activated product; wherein, the activation gas forms a pore structure by oxidative etching of the chemically activated product; Post - treatment: including sequentially performing pickling, water washing, filtration, and drying on the physically activated product to obtain a porous carbon material.

2. The method according to claim 1, wherein The physical activation includes low - temperature physical activation and high - temperature physical activation; the preset temperature includes a first preset temperature and a second preset temperature; The first preset temperature for low - temperature physical activation is 500 - 700 °C, the heating rate is 2 - 15 °C / min, and the activation time is 1 - 3 hours; After low - temperature physical activation, the pore structure is enlarged to form a microporous structure; The second preset temperature for high - temperature physical activation is 700 - 110 °C, the heating rate is 2 - 15 °C / min, and the activation time is 1 - 3 hours; After high - temperature physical activation, the microporous structure is enlarged to form a mesoporous and macroporous composite structure.

3. The method according to claim 1 or 2, characterized in that, The inert gas is any one of nitrogen, argon, neon, krypton, and xenon; The reaction gas is one or more gases among CO2, water vapor, ammonia, air, etc.; The mixing ratio of the reaction gas to the inert gas is 1:0.5 - 1:3; The total input amount of the activation gas is 1 - 5 times the mass of the chemically activated product.

4. The method according to claim 1 or 2, characterized in that, In the pretreatment, the crushing process uses a combination of a double - roll crusher and a ball mill, and a combination of a vibrating screen and an air classifier to achieve particle size classification; The roll gap of the double - roll crusher is dynamically adjusted by a hydraulic servo module, and the adjustment accuracy is ≤0.1 mm; Gradient crushing is performed using a double - roll crusher, the gap is set to 10 - 15 mm, the range of the roll surface temperature is ≤60 °C, the proportion of the part with an output particle size > 5 mm is < 10%, and the proportion of the part with an output particle size of 1 - 5 mm is ≥85%; The ball mill uses zirconia gradient grinding media, where the Φ10mm and Φ5mm grinding balls are filled in a volume ratio of 3:7 - 5:5, and is equipped with a nitrogen inert protection device. The ball-to-material ratio is 2:1 - 4:1, and the grinding time is 0.5 - 2h; the ball mill grinds in a nitrogen environment to 50 - 200μm; vibrating screening is carried out. The coarse particle layer, that is, the particle layer > 0.425mm, is returned to the ball mill for secondary crushing, and the medium particle layer, that is, the particle layer range is 0.15 - 0.425mm, enters the air separation fine treatment; during the air separation process, the set cutting particle size is 0.25 - 0.5μm, the classifier wheel speed is 1500 - 2500rpm, through the wind speed PID adjustment, the initial speed is set to 8m / s, and according to the particle size feedback ±1.5m / s, the particle size data is collected in real time, and the process parameters are dynamically adjusted: when the particle size after grinding deviates from the target value > 5%: adjust the ball mill speed ±2rpm or the grinding time ±5min.

5. The method according to claim 1 or 2, characterized in that, The drying of chemical activation and post-treatment uses a multi-stage combination of microwave drying and hot air circulation. The humidity sensor real-time feedback adjusts the drying time, and the moisture content is controlled < 2%; In the first drying stage, the drying time range is 20 - 40min, the total microwave power is 4.8kW, the microwave duty cycle is 80%, and hot air at 80 - 100°C is simultaneously introduced into the drying cavity, with a wind speed of 1.5 - 2.5m / s; In the second drying stage, the drying time range is 10 - 30min; the microwave is switched to the pulse mode, the duty cycle is 60%, the power is reduced to 3.6kW, and the hot air temperature decreases at a rate of 3°C every 2 - 5min, and is gradually cooled from 80 - 100°C to 50 - 70°C, and the wind speed is increased to 2.5 - 3.5m / s; In the third drying stage, the drying time range is 10 - 20min; the hot air is maintained at 40 - 50°C and dehumidified.

6. A porous carbon production system device with low-concentration chemical-physical coupling and intelligent continuous operation, characterized in that, The system includes: A crushing device, an inert gas preheater (1), a static mixer (2), an activation gas preheater (3), a carbonization fluidized bed reactor, an activation fluidized bed reactor, a product collection tank (9), a scrubber (12); Among them, the crushing device is used to crush the carbon source to obtain a carbon precursor; The inert gas preheater (1) is used to preheat the inert gas; the activation gas preheater (3) is used to preheat the activation gas; The static mixer (2) is used to mix the inert gas and the activation gas; The carbonization fluidized bed reactor is used to carry out a carbonization reaction on the carbon precursor to obtain a carbonized product; The activation fluidized bed reactor is used to carry out an activation reaction on the carbonized product to obtain an activated product; The product collection tank (9) is used to collect the porous carbon material; The scrubber (12) is used to purify the dust in the gas; Among them, the outlet of the inert gas preheater (1) and the outlet of the activation gas preheater (3) are connected to the static mixer (2); The outlet of the crushing device and the outlet of the static mixer (2) are both connected to the carbonization fluidized bed reactor; The material outlet of the carbonization fluidized bed reactor is connected to the material inlet of the activation fluidized bed reactor; the material outlet of the activation fluidized bed reactor is connected to the material inlet of the product collection tank (9); the gas outlet of the activation fluidized bed reactor is connected to the scrubber (12).

7. The system device according to claim 6, characterized in that, The carbonization fluidized bed reactor and the activation fluidized bed reactor are the same fluidized bed reactor.

8. The system device according to claim 6 or 7, characterized in that, The system further includes a tail gas waste heat recovery heat exchanger (11), the outlet of the tail gas waste heat recovery heat exchanger (11) is connected to an inert gas preheater (1) and a fluidized bed reactor, and the heat in the tail gas waste heat recovery heat exchanger (11) is used to heat the inert gas and provide the heat required for the reaction temperature of the fluidized bed reactor.

9. The system device according to claim 6 or 7, characterized in that, Filters (10) are provided at the gas outlets of the carbonization fluidized bed reactor and the product collection tank (9).

10. The system device according to claim 6 or 7, characterized in that, The carbonization fluidized bed reactor and the activation fluidized bed reactor are provided with an on-line laser porosity detector. Among them, the on-line laser porosity detector is used to feedback the porosity of the carbonized product or the activated product, and compare the porosity data monitored in real time with the set target porosity range, so as to adjust the activation time.

11. The system device according to claim 10, wherein The target porosity of the on-line laser porosity detector in the activation fluidized bed reactor is 80% - 90%. When the porosity is lower than the target porosity, one or more of the following measures are taken: Reduce the heating rate, extend the activation time, increase the flow rate of the activation gas, and adjust the pressure of the activation fluidized bed reactor.

12. The system device according to claim 6 or 7, characterized in that, For the coordinated feeding of inert gas and active gas, the system adopts flow ratio control. Based on the closed-loop control loop composed of a mass flow controller and a regulating valve, according to the preset ratio parameters, the multi-branch flow ratio is realized through the dynamic matrix control algorithm, and the feeding amounts of the inert gas and the activation gas are automatically adjusted; by collecting the flow signals of each branch in real time, the pulse width modulation signal is output through PID operation to drive the intelligent positioner to realize the non-linear compensation control of the regulating valve opening.

13. The system device according to claim 8, wherein The inert gas preheater and the tail gas waste heat recovery heat exchanger adopt a jacket type or shell-and-tube heat exchange structure, and the outlet temperature automatically changes the flux by adjusting the valve position stroke of the circulating water and circulating steam regulating valves, and maintains the outlet temperature within the range of set value ±2°C; when the outlet temperature of the inert gas preheater is lower than the set temperature, the circulating steam amount is increased; when the outlet tail gas temperature of the tail gas waste heat recovery heat exchanger is higher than the set temperature, the circulating cooling water usage is increased.

Images