A catalytic combustion treatment process for organic waste gas using activated carbon adsorption and concentration

Abstract

The present application relates to the field of waste gas treatment technology, and specifically to a catalytic combustion treatment process for organic waste gas using activated carbon adsorption and concentration, the process comprising: collecting organic waste gas, and entering an activated carbon adsorption bed for adsorption after pretreatment, switching the activated carbon adsorption bed after adsorption saturation, turning on the desorption fan, and performing desorption catalytic combustion; discharging high-temperature gas after catalytic combustion treatment, and entering a wind mixing box to mix with external air after preliminary cooling in a heat exchanger; after mixing, a portion of the gas enters a desorption pipeline for secondary adsorption in proportion, and the remaining portion enters a heat storage body, and enters a waste gas main pipeline after reaching a target temperature, and performs secondary adsorption with the waste gas, until the gas adsorbed by the activated carbon adsorption bed is discharged after being tested to meet the standard; determining the degree of regulation at each moment; obtaining the predicted value of the operating current at the next moment of each moment, and controlling the temperature of the heat storage body. The present application improves the adsorption efficiency of organic waste gas.

Description

Technical Field

[0001] The present application relates to the technical field of waste gas treatment, and in particular to a catalytic combustion treatment process for organic waste gas using activated carbon adsorption and concentration. Background Art

[0002] As people use more and more chemical products in large-scale production and life, the emission of volatile organic compounds is also increasing. The traditional "activated carbon adsorption + CO catalytic combustion" process uses activated carbon to adsorb and concentrate volatile organic compounds, and then uses a CO furnace to catalytically remove volatile organic compounds under the action of high temperature and catalyst.

[0003] However, in actual practice, the efficiency of catalytic combustion in CO furnaces is not 100%, which results in the presence of some waste gas in the gas after catalytic combustion. Therefore, if it is discharged directly, the adsorption effect will be poor, so it is necessary to perform secondary adsorption on the waste gas. However, catalytic combustion in CO furnaces will release a lot of heat, making it difficult to ensure secondary adsorption of waste gas at the optimal adsorption temperature of activated carbon. Summary of the invention

[0004] In order to solve the above technical problems, the present application provides a catalytic combustion treatment process for organic waste gas using activated carbon adsorption and concentration to solve the existing problems.

[0005] The present application discloses a catalytic combustion treatment process for organic waste gas using activated carbon adsorption and concentration, which adopts the following technical scheme:

[0006] An embodiment of the present application provides a catalytic combustion treatment process for organic waste gas using activated carbon adsorption concentration, the process comprising the following steps:

[0007] Collect organic waste gas, pre-treat it and then enter the activated carbon adsorption bed for adsorption. After adsorption saturation, switch to the activated carbon adsorption bed, turn on the desorption fan, and perform desorption catalytic combustion.

[0008] After catalytic combustion treatment, high-temperature gas is discharged, and after preliminary cooling in the heat exchanger, it enters the air mixing box to mix with the outside air; after mixing, a portion of it enters the desorption pipeline for secondary adsorption in proportion, and the remaining part enters the heat storage body and reaches the target temperature before entering the exhaust gas main pipeline for secondary adsorption with the exhaust gas, until the gas adsorbed by the activated carbon adsorption bed is discharged after being tested and meets the standards; the remaining part is in the heat storage body, and the temperature control process of the heat storage body is as follows:

[0009] Collecting the carbon dioxide concentration in the high-temperature gas at each moment, collecting the operating current of the heat storage body at each moment, and collecting the temperature of the heat storage body at the air inlet and the air outlet at each moment;

[0010] Based on the difference between the carbon dioxide concentration at each moment and the carbon dioxide concentration in standard air, the organic enrichment at each moment is determined; the distribution range and disorder degree of the temperature at the air inlet at adjacent moments of each moment are analyzed, and the mixed air disorder degree at each moment is determined in combination with the organic enrichment;

[0011] Based on the temperature difference between the air inlet and the air outlet at each moment, combined with the carbon dioxide concentration in the high-temperature gas, the indirect influence degree of the heat storage body regulation at each moment is determined; the regulation degree at each moment is obtained by combining the mixed air disorder degree with the indirect influence degree;

[0012] Using the adjustment degree at each moment, the temperature at the air inlet, and the operating current to perform nonlinear fitting, a predicted operating current value at the next moment of each moment is obtained to control the temperature of the heat storage body;

[0013] Among them, the indirect influence degree is the ratio of the temperature difference at each moment to the carbon dioxide concentration in the high-temperature gas; the adjustment degree is the normalized value of the sum of the mixed air disorder degree and the indirect influence degree.

[0014] In one embodiment, the air volume treated by the activated carbon adsorption bed is: 25000~30000m 3 / h, the length, width and height are 3000×3000×3000mm respectively. The activated carbon adopts honeycomb carbon with an iodine value of 800~1000mg / g. It is filled in a brick-like manner with a filling height of 600~800mm.

[0015] In one embodiment, the catalytic combustion process air volume is: 2000~3000m 3 / h, the reaction temperature of the catalytic combustion is 200-300°C, and the catalyst is a palladium catalyst.

[0016] In one embodiment, the air entering the air mixing box is mixed with the outside air so that the temperature is controlled at 80°C to 120°C.

[0017] In one embodiment, the proportional value is 50% to 60%.

[0018] In one embodiment, the target temperature is 40-50°C.

[0019] In one embodiment, the determination of the air mixing disorder degree includes:

[0020] The sum of the distribution range and the degree of disorder of the temperature at the air inlet in adjacent moments at each moment is calculated, and the mixed air disorder degree is the product of the sum and the organic enrichment degree.

[0021] In one embodiment, the performing nonlinear fitting comprises:

[0022] Using a polynomial fitting algorithm, a fitting function is obtained based on the adjustment degree, the temperature at the air inlet, and the operating current at all times before each moment. , where I is the operating current of the heat storage body at each moment, w is the temperature at the air inlet of the heat storage body at each moment, D is the regulation degree at each moment, and f() is the fitting function of the operating current with respect to the temperature at the air inlet of the heat storage body and the regulation degree.

[0023] This application has at least the following beneficial effects:

[0024] The present application collects the carbon dioxide concentration at each moment in the high-temperature gas discharged after catalytic combustion treatment, collects the operating current of the heat storage body at each moment, and respectively collects the temperature of the heat storage body at the air inlet and the air outlet at each moment; based on the difference between the carbon dioxide concentration at each moment and the carbon dioxide concentration in the standard air, the organic enrichment at each moment is determined; the organic enrichment reflects the heat output in the catalytic combustion furnace; the distribution range and disorder degree of the temperature at the air inlet at adjacent moments at each moment are analyzed, and combined with the organic enrichment, the mixed air disorder degree at each moment is determined; the mixed air disorder degree reflects the uneven spatial distribution of the mixed gas in the mixing box, reflects the degree of influence on the temperature at the air inlet of the heat storage body, and improves the accuracy of subsequent heat storage body temperature control; based on the temperature difference between the air inlet and the air outlet at each moment, combined with the carbon dioxide concentration in the high-temperature gas, the heat storage body at each moment is determined. The indirect influence degree of regulation; combining the mixed air disorder degree and the indirect influence degree, the regulation degree at each moment is obtained; the regulation degree reflects the degree to which the temperature of the heat storage body needs to be regulated, and reflects the strength of the temperature regulation of the heat storage body. Further, the regulation degree at each moment, the temperature at the air inlet, and the operating current are used for nonlinear fitting to obtain the operating current prediction value of the next moment at each moment, and the temperature of the heat storage body is controlled. The hysteresis and distortion of the temperature change in the heat storage body in the actual process are taken into account, and the regulation accuracy of the operating current of the heat storage body and the stability of the temperature of the heat storage body output gas are improved, thereby improving the adsorption efficiency of the organic waste gas; and the present application performs secondary adsorption on the organic waste gas, which effectively increases the contact time between the waste gas and the activated carbon, improves the treatment efficiency of the catalytic combustion of the organic waste gas, and ensures that the catalytic combustion treatment process of the organic waste gas is stable and meets the emission standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 A flow chart of the steps of a catalytic combustion treatment process for organic waste gas using activated carbon adsorption and concentration provided in this application;

[0027] Figure 2 It is a schematic diagram of the catalytic combustion treatment process;

[0028] Figure 3 This is the flow chart of heat storage body temperature control. DETAILED DESCRIPTION

[0029] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following is a detailed description of the specific implementation method, structure, characteristics and effects of a catalytic combustion treatment process of organic waste gas using activated carbon adsorption and concentration proposed in the present application in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0030] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0031] The specific scheme of the catalytic combustion treatment process of organic waste gas using activated carbon adsorption and concentration provided by the present application is described in detail below with reference to the accompanying drawings.

[0032] Example 1

[0033] Example 1 provides a catalytic combustion treatment process for organic waste gas using activated carbon adsorption and concentration. For the flow chart of the steps, please refer to Figure 1 , the specific process steps are as follows:

[0034] (1) Collection and pretreatment of organic waste gas: In this embodiment, during the chemical production process, a gas collection hood is installed at the exhaust system to collect organic compounds (Volatile Organic Compounds, VOCs), referred to as waste gas, generated during the industrial production process, and the waste gas is pretreated using dry filtration equipment.

[0035] (2) Adsorption on adsorption bed: The pre-treated exhaust gas is adsorbed on an activated carbon adsorption bed. In this embodiment, there are two activated carbon adsorption beds. During operation, one activated carbon adsorption bed is in adsorption and the other activated carbon adsorption bed is in desorption standby;

[0036] In this embodiment, the treated air volume of the activated carbon adsorption bed is 25000m 3 / h, the size of a single activated carbon adsorption bed is That is, the length, width and height of the activated carbon adsorption bed are all 3000mm. The activated carbon adopts honeycomb carbon with an iodine value of 800mg / g. It is filled with bricks and the filling height is 600mm. Each activated carbon adsorption bed is filled with 3m 3 , the wind speed of the activated carbon layer filtration is 0.8m / s. The activated carbon adsorption bed is recorded as the adsorption bed.

[0037] (3) Desorption + catalytic combustion: When the activated carbon adsorption bed is saturated with adsorption, switch the activated carbon adsorption bed, turn on the desorption fan, and enter the desorption regeneration stage. It should be noted that the two activated carbon adsorption beds cycle for adsorption + desorption catalytic combustion, that is, one activated carbon adsorption bed performs the adsorption process, and the other activated carbon adsorption bed performs the desorption catalytic combustion process. The treatment air volume set in the catalytic combustion furnace is 2000m 3 / h, the heat exchanger in the catalytic combustion furnace generates 80℃ hot air to back-blow and regenerate the saturated activated carbon adsorption bed, and the high-concentration organic matter in the activated carbon adsorption bed is sent to the catalytic combustion furnace. Under the temperature of 280℃ and the catalytic action of the palladium catalyst, the exhaust gas is decomposed into carbon dioxide and water. The catalytic combustion reaction process is:

[0038]

[0039] The oxidation and decomposition process of high-concentration organic waste gas in the catalytic combustion furnace will release a large amount of heat, causing the catalytic combustion reaction to discharge high-temperature gas. The heat exchanger in the catalytic combustion furnace is used to initially cool the high-temperature gas, and then it is sent to the mixing box. The cooling fan is turned on to mix it with the outside air in the mixing box. The temperature is controlled at 80°C, and then 50% of the mixed gas enters the desorption pipeline for secondary adsorption. The remaining 50% of the gas enters the heat storage body, and after continuing to cool down to reach the target temperature, it enters the exhaust gas main pipeline and undergoes secondary adsorption with the exhaust gas until the gas adsorbed by the activated carbon adsorption bed is tested and meets the standards and is then extracted and discharged by the main fan. The target temperature in this embodiment is 40°C. The schematic diagram of the catalytic combustion treatment process is shown in the figure. Figure 2 shown.

[0040] It should be noted that the initial cooling of the high-temperature gas is to cool it to 80°C. If the heat in the catalytic combustion furnace is too high and the heat exchanger in the catalytic combustion furnace cannot cool the high-temperature gas to 80°C, then after the high-temperature gas is sent into the mixing box, it is necessary to turn on the supplementary cooling fan to mix with the outside air in the mixing box and control the temperature at 80°C. Specifically, a temperature sensor is installed at the entrance of the mixing box. If the gas temperature is detected to be greater than or equal to 80°C, the supplementary cooling fan is turned on to mix with the outside air in the mixing box and control the temperature at 80°C. Otherwise, the supplementary cooling fan is not turned on after entering the mixing box. The standard for meeting the standard is to meet the document "Volatile Organic Compound Unorganized Emission Control Standard" (GB 37822-2019), and the heat storage body is a solid heat storage electric boiler. In this embodiment, in order to improve the safety of the catalytic combustion treatment process, the following settings are adopted:

[0041] ① The activated carbon adsorption bed, catalytic combustion furnace and pipeline are equipped with temperature detection probes. The temperature detection signal is linked with the equipment inlet and outlet valves and air supply fans to ensure that there is no over-temperature inside the equipment;

[0042] ② The activated carbon adsorption bed is equipped with an automatic spray system. Once the internal temperature exceeds the set value, the automatic spray system will be activated;

[0043] ③ A flame arrester is installed at the air inlet of the catalytic combustion furnace and an explosion-proof pressure relief device is installed on the main body to ensure the safety of the equipment;

[0044] ④ The instruments of important parameters are designed with redundancy, that is, multiple detection probes are set at a single point. In this embodiment, two detection probes are set at a single point.

[0045] In the "activated carbon adsorption + catalytic combustion" treatment process, the combustion efficiency of the enriched gas in the catalytic combustion furnace is not 100%, and there may be residual organic gas. The heat storage body is used to further cool the desorbed gas, so that the exhaust gas of the heat storage body is mixed with the gas in the exhaust gas main pipeline, ensuring that the adsorption of organic matter in the exhaust gas can be carried out at the optimal adsorption temperature of the activated carbon adsorption bed, thereby improving the overall adsorption efficiency.

[0046] In order to achieve the exhaust gas temperature that meets the optimal adsorption temperature of activated carbon, the temperature of the heat storage body output gas needs to be kept stable. In order to ensure that the temperature of the heat storage body output gas is constant and maintain the target temperature, the temperature of the heat storage body is controlled, specifically:

[0047] Step S1, collecting the carbon dioxide concentration in the high-temperature gas produced by the catalytic combustion reaction at each moment, collecting the operating current of the heat storage body at each moment, and collecting the temperature of the heat storage body at the air inlet and the air outlet at each moment.

[0048] The operating current value of the heat storage body at each moment is collected through the current sensor, and the temperature sensors are respectively deployed at the air inlet and air outlet of the heat storage body to obtain the temperature of the air inlet and air outlet of the heat storage body at each moment. At the same time, a thermal conductor carbon dioxide sensor is deployed at the outlet of the desorption fan to measure the carbon dioxide concentration at each moment in the high-temperature gas produced by the catalytic combustion reaction. It should be noted that all sensors in this embodiment adopt the same frequency sampling, and the sampling interval of the sensor is 0.5s. The implementer can set it according to the actual situation, and this embodiment does not limit it here.

[0049] Step S2: Determine the organic enrichment at each moment based on the difference between the carbon dioxide concentration at each moment and the carbon dioxide concentration in standard air; analyze the distribution of the temperature at the air inlet at adjacent moments of each moment, and determine the mixed air disorder at each moment in combination with the organic enrichment.

[0050] During the manufacturing process, volatile organic compounds (VOCs) are closely related to the production links and environmental conditions. Therefore, during the adsorption process, the content of VOCs in the exhaust gas is usually uncontrollable, causing the activated carbon to adsorb VOCs and change with the organic matter in the exhaust gas, resulting in changes in the heat generated during the desorption catalytic combustion process, thereby affecting the temperature in the air mixing box and further affecting the stability of the temperature in the heat storage body.

[0051] Normally, the high-temperature gas generated by the catalytic combustion furnace is transported to the air mixing box, where the room temperature gas is supplemented by the cooling fan and mixed with the high-temperature gas to reach the desorption temperature of the adsorption bed. A portion of the mixed gas will then be transferred to the heat storage body, where the temperature of the mixed gas is controlled to meet the optimal adsorption temperature of the activated carbon. However, due to the gas blown in by the cooling fan, the diffusion state of the gas cannot be determined when it is mixed in the air mixing box, which will lead to insufficient heat exchange of the gas, causing the temperature of the mixed gas to be unevenly distributed in the air mixing box space.

[0052] Therefore, if the current of the heat storage body is regulated only by the temperature value at the air inlet of the heat storage body, temperature hysteresis will occur, and due to the influence of the air flow in the air mixing box, the temperature value at the air inlet of the heat storage body will fluctuate, further affecting the stability of the temperature control of the heat storage body. In order to determine the temperature situation in the air mixing box, it is necessary to analyze it in combination with the situation of the catalytic combustion furnace.

[0053] When the activated carbon is more enriched in organic waste gas VOCs, the more organic matter is obtained during desorption, and more heat can be produced in the catalytic combustion furnace. At this time, the concentration of carbon dioxide produced by combustion will be higher. Therefore, based on the difference between the carbon dioxide concentration in the high-temperature gas produced by the catalytic combustion reaction at each moment and the carbon dioxide concentration in the standard air, the organic enrichment at each moment is determined. It should be noted that the difference represents the degree of difference between the two variables, and can be calculated by the absolute value of the difference, the square of the difference, etc. This embodiment uses the absolute value of the difference as the calculation method of the difference. In this embodiment, the calculation method of the organic enrichment can be:

[0054] ; In the formula, A represents the organic enrichment at each moment, V represents the carbon dioxide concentration in the high-temperature gas produced by the catalytic combustion furnace at each moment, Indicates the carbon dioxide concentration in the air under standard conditions.

[0055] The organic enrichment can reflect the heat output in the catalytic combustion furnace at each moment. If the VOCs organic matter enrichment content is higher, more heat can be produced per unit time, and more carbon dioxide will be produced at the same time. The obtained carbon dioxide content will be much higher than the carbon dioxide concentration in the air under standard conditions, making the organic enrichment value at each moment larger.

[0056] The organic enrichment can be used to indicate the enrichment of organic matter VOCs, and can further determine the uneven distribution of the mixed gas in the air mixing box. As the room temperature gas of the supplementary cooling fan enters the air mixing box, it will drive the gas flow in the air mixing box, causing the temperature value at the air inlet of the heat storage body to fluctuate. Therefore, at each moment, the temperature values ​​at the air inlet of the heat storage body at all moments within 30 seconds before each moment are combined into a temperature influence sequence at each moment, and the distribution range and degree of disorder of the temperature influence sequence are analyzed, and the fusion result of the distribution range, the degree of disorder, and the organic enrichment is determined as the mixed air disorder at each moment. The implementer can set the length of the temperature influence sequence according to the actual situation, and this embodiment does not limit it here.

[0057] It should be noted that, in this embodiment, the distribution range is calculated using the range calculation method, the degree of confusion is calculated using the information entropy calculation method, and fusion means combining multiple variables, which can be calculated specifically by addition, multiplication, or a combination of addition and multiplication.

[0058] In this embodiment, the calculation method of the mixed air disorder degree at each moment can be:

[0059] ; In the formula, is the air chaos at each moment, A represents the organic enrichment at each moment, is the range of the temperature impact sequence at each moment, is the information entropy of the temperature influence sequence at each moment.

[0060] If the fluctuation of the temperature influence sequence is more intense at each moment, it indicates that the spatial distribution of the mixed gas in the air mixing box is more uneven in the corresponding time period, and the range and information entropy values ​​of the temperature influence sequence are larger. At the same time, if the catalytic combustion is more intense at each moment, the spatial uneven distribution of the mixed gas can be further aggravated, the corresponding organic enrichment value is larger, and finally the value of the mixed air disorder is larger, indicating that the temperature unevenness in the air mixing box is more serious at this time, which will affect the temperature of the air inlet in the heat storage body, and the temperature control ability of the heat storage body needs to be further increased.

[0061] Step S3: Based on the temperature difference between the air inlet and the air outlet at each moment, combined with the carbon dioxide concentration in the high-temperature gas, determine the indirect influence degree of the heat storage body regulation at each moment; combine the mixed air disorder and the indirect influence degree to obtain the regulation degree at each moment.

[0062] Since carbon dioxide is a greenhouse gas, its molecular structure can absorb and radiate heat, hindering the further diffusion of heat. Therefore, the higher the concentration of carbon dioxide produced by catalytic combustion, the more heat it can absorb and radiate, which is more helpful for the thermal storage body to keep warm. The purpose of regulating the thermal storage body is to keep the temperature of the thermal storage body constant, unaffected by the temperature of the air inlet, and ensure the uniformity of the output gas temperature.

[0063] Based on the carbon dioxide concentration in the high-temperature gas produced by the catalytic combustion furnace and the temperature change of the heat storage body, the indirect influence degree of the heat storage body regulation at each moment is constructed, and the expression is:

[0064] ; In the formula, C is the indirect influence degree of heat storage body regulation at each moment, is the temperature difference between the air inlet and outlet of the heat storage body at each moment, and V represents the carbon dioxide concentration in the high-temperature gas produced by the catalytic combustion furnace at each moment.

[0065] It should be noted that the temperature difference is the absolute value of the temperature difference between the air inlet and the air outlet of the heat storage body at each moment.

[0066] If the temperature difference between the air inlet temperature and the air outlet temperature of the heat storage body at each moment is greater, it indicates that the regulation of the heat storage body needs to be strengthened at this time. At this time, the lower the carbon dioxide concentration in the high-temperature gas produced by the catalytic combustion furnace, the less conducive it is to the heat preservation of the heat storage body. Therefore, the greater the indirect influence degree obtained, the more it is necessary to strengthen the regulation of the heat storage body.

[0067] Thus, the adjustment degree at each moment is determined by combining the mixed wind disorder degree and the indirect influence degree, and the adjustment degree is the normalized value of the sum of the mixed wind disorder degree and the indirect influence degree at each moment. In this embodiment, the normalization method adopts the Sigmoid function, and the implementer can select other existing feasible normalization methods according to actual conditions, and this embodiment does not limit it here.

[0068] The adjustment degree is used to reflect the degree of intervention in the regulation of the heat storage body at each moment, that is, when the organic enrichment is more, more heat can be catalytically burned, which further aggravates the uneven temperature space in the air mixing box, thereby affecting the temperature difference between the air inlet and outlet of the heat storage body, and it is necessary to increase the regulation of the heat storage body.

[0069] Step S4: nonlinearly fitting is performed using the adjustment degree at each moment, the temperature at the air inlet, and the operating current to obtain the current prediction value at the next moment of each moment, and the temperature of the heat storage body is controlled.

[0070] The control method for the heat storage body is: based on the temperature of the air inlet of the heat storage body, the operating current of the heat storage body is adjusted to make the temperature of the gas output by the heat storage body constant, and the gas discharged from the heat storage body is mixed with the organic waste gas in the exhaust gas main pipe, so that the adsorption of the exhaust gas in the main pipe is carried out at the optimal adsorption temperature of the activated carbon, thereby improving the adsorption efficiency of the organic gas in the exhaust gas.

[0071] Since the overall adsorption effect of activated carbon is relatively high in the initial stage of adsorption, this embodiment does not intervene in the heat storage body within the first 30 minutes of the catalytic combustion treatment. Based on the 30th minute of the catalytic combustion treatment and the time period thereafter, based on the operating current value of the heat storage body at all times before each moment, the temperature value at the air inlet, and the regulation degree, a polynomial fitting algorithm is used, in which the order of the term is set to 3, the convergence tolerance is 5%, and the maximum number of iterations is 200 times, to obtain the fitting relationship between the operating current value of the heat storage body, the temperature value at the air inlet, and the regulation degree, that is, , where I is the operating current of the heat storage body at each moment, w is the temperature at the air inlet of the heat storage body at each moment, D is the regulation degree at each moment, and f() is the fitting function of the operating current with respect to the temperature at the air inlet of the heat storage body and the regulation degree. Among them, the purpose of the regulation degree at each moment is to measure the nonlinearity of the current value and the air inlet temperature value at a single sampling moment, so that the fitting relationship can be more accurate. The polynomial fitting algorithm is an existing well-known technology. The implementer can select other existing feasible nonlinear fitting algorithms according to actual conditions, and this embodiment does not limit it here.

[0072] Based on the fitting relationship, the operating current value of the thermal storage body at the next moment is predicted. With the goal of minimizing the temperature fluctuation of the gas output by the thermal storage body, the operating current value at each moment and the operating current value predicted at the next moment are used as the input of the fuzzy controller. The fuzzy controller generates a corresponding PWM (Pulse Width Modulation) signal based on the operating current value that needs to be adjusted to control the relay in the thermal storage body, thereby achieving temperature control of the thermal storage body, so that the thermal storage body can output gas with stable temperature and complete the temperature control of the thermal storage body. The thermal storage body temperature control flow chart is as follows: Figure 3 shown.

[0073] Example 2

[0074] Example 2 provides a catalytic combustion treatment process for organic waste gas using activated carbon adsorption and concentration. For the flow chart of the steps, please refer to Figure 1 , the specific process steps are as follows:

[0075] (1) Collection and pretreatment of organic waste gas: In this embodiment, during the chemical production process, a gas collection hood is installed at the exhaust system to collect organic compounds (Volatile Organic Compounds, VOCs), referred to as waste gas, generated during the industrial production process, and the waste gas is pretreated using dry filtration equipment.

[0076] (2) Adsorption on adsorption bed: The pre-treated exhaust gas is adsorbed on an activated carbon adsorption bed. In this embodiment, there are two activated carbon adsorption beds. During operation, one activated carbon adsorption bed is in adsorption and the other activated carbon adsorption bed is in desorption standby;

[0077] In this embodiment, the air volume treated by the activated carbon adsorption bed is 28000m 3 / h, the size of a single activated carbon adsorption bed is That is, the length, width and height of the activated carbon adsorption bed are all 3000mm. The activated carbon adopts honeycomb carbon with an iodine value of 900mg / g. It is filled with bricks and the filling height is 700mm. Each activated carbon adsorption bed is filled with 3m 3 The wind speed of activated carbon layer filtration is 1.0m / s.

[0078] (3) Desorption + catalytic combustion: When the activated carbon adsorption bed is saturated with adsorption, switch the activated carbon adsorption bed, turn on the desorption fan, and enter the desorption regeneration stage. It should be noted that the two activated carbon adsorption beds cycle for adsorption + desorption catalytic combustion, that is, one activated carbon adsorption bed performs the adsorption process, and the other activated carbon adsorption bed performs the desorption catalytic combustion process. The treatment air volume set in the catalytic combustion furnace is 2500m 3 / h, the heat exchanger in the catalytic combustion furnace generates 100℃ hot air to back-blow and regenerate the saturated activated carbon adsorption bed, and the high-concentration organic matter in the activated carbon adsorption bed is sent to the catalytic combustion furnace. Under the temperature condition of 290℃ and the catalytic action of the palladium catalyst, the exhaust gas is decomposed into carbon dioxide and water. The catalytic combustion reaction process is:

[0079]

[0080] The oxidation and decomposition process of high-concentration organic waste gas in the catalytic combustion furnace will release a lot of heat, so that the catalytic combustion reaction will discharge high-temperature gas. The heat exchanger in the catalytic combustion furnace is used to initially cool the high-temperature gas, and then it is sent to the mixing box to mix with the outside air in the mixing box. The temperature is controlled at 100°C, and then 55% of the mixed gas enters the desorption pipeline for secondary adsorption. The remaining 45% of the gas enters the heat storage body, continues to cool down to reach the target temperature, and enters the exhaust gas main pipeline. After secondary adsorption, it is adsorbed with the exhaust gas until the gas adsorbed by the activated carbon adsorption bed is tested and meets the standard and is extracted and discharged by the main fan. The target temperature in this embodiment is 45°C.

[0081] It should be noted that the initial cooling of the high-temperature gas is to cool it to 100°C. If the heat in the catalytic combustion furnace is too high and the heat exchanger in the catalytic combustion furnace cannot cool the high-temperature gas to 100°C, then after the high-temperature gas is sent into the mixing air box, the supplementary cooling fan needs to be turned on to mix it with the outside air in the mixing air box and the temperature is controlled at 100°C. Specifically, a temperature sensor is installed at the inlet of the mixing air box. If the gas temperature is detected to be greater than or equal to 100°C, the supplementary cooling fan is turned on to mix it with the outside air in the mixing air box and the temperature is controlled at 100°C. Otherwise, the supplementary cooling fan is not turned on after entering the mixing air box.

[0082] The remaining parts are subjected to catalytic combustion treatment in exactly the same steps as in Example 1 of the present application.

[0083] Example 3

[0084] Example 3 provides a catalytic combustion treatment process for organic waste gas using activated carbon adsorption and concentration. For the flow chart of the steps, please refer to Figure 1 , the specific process steps are as follows:

[0085] (1) Collection and pretreatment of organic waste gas: In this embodiment, during the chemical production process, a gas collection hood is installed at the exhaust system to collect organic compounds (Volatile Organic Compounds, VOCs), referred to as waste gas, generated during the industrial production process, and the waste gas is pretreated using dry filtration equipment.

[0086] (2) Adsorption on adsorption bed: The pre-treated exhaust gas is adsorbed on an activated carbon adsorption bed. In this embodiment, there are two activated carbon adsorption beds. During operation, one activated carbon adsorption bed is in adsorption and the other activated carbon adsorption bed is in desorption standby;

[0087] In this embodiment, the air volume treated by the activated carbon adsorption bed is 30000m 3 / h, the size of a single activated carbon adsorption bed is That is, the length, width and height of the activated carbon adsorption bed are all 3000mm. The activated carbon uses honeycomb carbon with an iodine value of 1000mg / g. It is filled in a brick-built manner with a filling height of 800mm. Each activated carbon adsorption bed is filled with 3m 3 The wind speed of activated carbon layer filtration is 1.2m / s.

[0088] (3) Desorption + catalytic combustion: When the activated carbon adsorption bed is saturated with adsorption, switch the activated carbon adsorption bed, turn on the desorption fan, and enter the desorption regeneration stage. It should be noted that the two activated carbon adsorption beds cycle for adsorption + desorption catalytic combustion, that is, one activated carbon adsorption bed performs the adsorption process, and the other activated carbon adsorption bed performs the desorption catalytic combustion process. The treatment air volume set in the catalytic combustion furnace is 3000m 3 / h, the heat exchanger in the catalytic combustion furnace generates 120℃ hot air to back-blow and regenerate the saturated activated carbon adsorption bed, and the high-concentration organic matter in the activated carbon adsorption bed is sent to the catalytic combustion furnace. Under the temperature condition of 300℃ and the catalytic action of the palladium catalyst, the exhaust gas is decomposed into carbon dioxide and water. The catalytic combustion reaction process is:

[0089]

[0090] The oxidation and decomposition process of high-concentration organic waste gas in the catalytic combustion furnace will release a lot of heat, so that the catalytic combustion reaction will discharge high-temperature gas. The heat exchanger in the catalytic combustion furnace is used to initially cool the high-temperature gas, and then it is sent to the mixing box to mix with the outside air in the mixing box. The temperature is controlled at 120°C, and then 60% of the mixed gas enters the desorption pipeline for secondary adsorption. The remaining 40% of the gas enters the heat storage body, continues to cool down to reach the target temperature, and enters the exhaust gas main pipeline. After secondary adsorption, it is adsorbed with the exhaust gas until the gas adsorbed by the activated carbon adsorption bed is extracted and discharged by the main fan after being tested and meets the standard. The target temperature in this embodiment is 50°C.

[0091] It should be noted that the initial cooling of the high-temperature gas is to cool it to 120°C. If the heat in the catalytic combustion furnace is too high and the heat exchanger in the catalytic combustion furnace cannot cool the high-temperature gas to 120°C, then after the high-temperature gas is sent into the mixing air box, it is necessary to turn on the supplementary cooling fan to mix it with the outside air in the mixing air box and control the temperature at 120°C. Specifically, a temperature sensor is installed at the inlet of the mixing air box. If the gas temperature is detected to be greater than or equal to 120°C, the supplementary cooling fan is turned on to mix it with the outside air in the mixing air box and control the temperature at 120°C. Otherwise, the supplementary cooling fan is not turned on after entering the mixing air box.

[0092] The remaining parts are subjected to catalytic combustion treatment in exactly the same steps as in Example 1 of the present application.

[0093] It should be noted that the above sequence of the embodiments of the present application is for description only and does not represent the advantages and disadvantages of the embodiments. The above is a description of a specific embodiment of this specification. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0094] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0095] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Modifications to the technical solutions recorded in the aforementioned embodiments, or equivalent replacement of some of the technical features therein, do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A catalytic combustion treatment process for organic waste gas using activated carbon adsorption and concentration, characterized in that: The process includes the following steps: Collect organic waste gas, pre-treat it and then enter the activated carbon adsorption bed for adsorption. After adsorption saturation, switch to the activated carbon adsorption bed, turn on the desorption fan, and perform desorption catalytic combustion. After catalytic combustion treatment, high-temperature gas is discharged, and after preliminary cooling in the heat exchanger, it enters the air mixing box to mix with the outside air; after mixing, a portion of it enters the desorption pipeline for secondary adsorption in proportion, and the remaining part enters the heat storage body and reaches the target temperature before entering the exhaust gas main pipeline for secondary adsorption with the exhaust gas, until the gas adsorbed by the activated carbon adsorption bed is discharged after being tested and meets the standards; the remaining part is in the heat storage body, and the temperature control process of the heat storage body is as follows: Collecting the carbon dioxide concentration in the high-temperature gas at each moment, collecting the operating current of the heat storage body at each moment, and collecting the temperature of the heat storage body at the air inlet and the air outlet at each moment; Based on the difference between the carbon dioxide concentration at each moment and the carbon dioxide concentration in standard air, the organic enrichment at each moment is determined; the distribution range and disorder degree of the temperature at the air inlet at adjacent moments of each moment are analyzed, and the mixed air disorder degree at each moment is determined in combination with the organic enrichment; Based on the temperature difference between the air inlet and the air outlet at each moment, combined with the carbon dioxide concentration in the high-temperature gas, the indirect influence degree of the heat storage body regulation at each moment is determined; the regulation degree at each moment is obtained by combining the mixed air disorder degree with the indirect influence degree; The adjustment degree at each moment, the temperature at the air inlet, and the operating current are used to perform nonlinear fitting to obtain the operating current prediction value at the next moment of each moment, and the temperature of the heat storage body is controlled, and the heat storage body is a solid heat storage electric furnace; Among them, the indirect influence degree is the ratio of the temperature difference at each moment to the carbon dioxide concentration in the high-temperature gas; the adjustment degree is the normalized value of the sum of the mixed air disorder degree and the indirect influence degree.

2. The catalytic combustion treatment process for organic waste gas using activated carbon adsorption and concentration as claimed in claim 1, characterized in that: The processing air volume of the activated carbon adsorption bed is: 25000~30000m 3 / h, the length, width and height are 3000×3000×3000mm respectively. The activated carbon adopts honeycomb carbon with an iodine value of 800~1000mg / g. It is filled in a brick-like manner with a filling height of 600~800mm.

3. The catalytic combustion treatment process for organic waste gas using activated carbon adsorption and concentration as claimed in claim 1, characterized in that: The catalytic combustion treatment air volume is: 2000~3000m 3 / h, the reaction temperature of the catalytic combustion is 200-300°C, and the catalyst is a palladium catalyst.

4. The catalytic combustion treatment process for organic waste gas using activated carbon adsorption and concentration as claimed in claim 1, characterized in that: The air entering the air mixing box is mixed with the outside air to control the temperature at 80°C to 120°C.

5. The catalytic combustion treatment process for organic waste gas using activated carbon adsorption and concentration as claimed in claim 1, characterized in that: The proportional value is 50% to 60%.

6. The catalytic combustion treatment process for organic waste gas using activated carbon adsorption and concentration as claimed in claim 1, characterized in that: The target temperature is 40~50℃.

7. The catalytic combustion treatment process for organic waste gas using activated carbon adsorption and concentration as claimed in claim 1, characterized in that: The determination of the mixed air disorder degree includes: The sum of the distribution range and the degree of disorder of the temperature at the air inlet in adjacent moments at each moment is calculated, and the mixed air disorder degree is the product of the sum and the organic enrichment degree.

8. The catalytic combustion treatment process for organic waste gas using activated carbon adsorption and concentration as claimed in claim 1, characterized in that: The nonlinear fitting comprises: Using a polynomial fitting algorithm, a fitting function is obtained based on the adjustment degree, the temperature at the air inlet, and the operating current at all times before each moment. , where I is the operating current of the heat storage body at each moment, w is the temperature at the air inlet of the heat storage body at each moment, D is the regulation degree at each moment, and f() is the fitting function of the operating current with respect to the temperature at the air inlet of the heat storage body and the regulation degree.

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