Rapid evaluation method for desorption effect of activated carbon for desulfurization and denitrification

Abstract

The invention provides a rapid evaluation method for the desorption effect of activated carbon for desulfurization and denitrification. The rapid evaluation method comprises the following steps: S1, obtaining the total amount M1 of elemental sulfur adsorbed by the activated carbon in an adsorption tower of a desulfurization and denitrification system; s2, obtaining the total amount Mr of elemental sulfur desorbed by the activated carbon in a desorption tower of the desulfurization and denitrification system; s3, calculating an activated carbon analysis effect evaluation parameter P; and S4, outputting an analysis tower regulation and control instruction according to the P value. According to the rapid evaluation method for the desorption effect of the activated carbon for desulfurization and denitrification, the desorption effect is evaluated, regulated and controlled in real time by quantifying the ratio of the total amount of adsorbed sulfur to the total amount of desorbed sulfur on the basis of the sulfur element mass conservation principle.

Description

Technical Field

[0001] The present invention relates to the technical field of activated carbon desulfurization and denitrification, and in particular to a method for quickly evaluating the analytical effect of activated carbon for desulfurization and denitrification. Background Art

[0002] Activated carbon desulfurization and denitrification technology is a technology that uses the physical adsorption and chemical catalysis of activated carbon (or activated carbon) to achieve the simultaneous removal of SO2 and NO in flue gas. X This dry purification technology removes pollutants such as sulfur, dust, and heavy metals. Through the cyclic adsorption-regeneration process of activated carbon, this technology achieves the dual goals of efficient pollutant removal and sulfur resource recovery. It is widely used in industrial flue gas treatment fields such as coal-fired power plants and steel sintering.

[0003] The activated carbon desulfurization and denitrification process mainly includes the adsorption stage and the regeneration stage. Specifically, the activated carbon physically adsorbs SO2 through the micropores in the adsorption tower and catalytically oxidizes it into sulfuric acid (H2SO4) or sulfate (such as (NH4)2SO4) at the surface active sites; at the same time, it adsorbs NO X The activated carbon reacts with the injected NH3 in the micropores to produce nitrogen (N2) and H2O; the adsorbed activated carbon is transported to the desorption tower, where the adsorbed sulfides (mainly sulfuric acid and ammonium salts) decompose at a high temperature of 400°C and release high-concentration SO2 gas; in order to improve economic benefits and resource utilization, industrial systems usually transport the SO2 gas released from the desorption tower to the supporting acid production system, converting it into commercial sulfuric acid (H2SO4) for recycling and utilization, thereby realizing sulfur resource utilization. Therefore, the sulfur analyzed by the activated carbon in the desorption tower mainly enters the acid production system, and most of it is converted into sulfuric acid. In addition, the desorption process of the activated carbon in the desorption tower will produce sulfur-containing wastewater, which mainly comes from the condensation of water vapor in the thermal desorption process. It contains trace amounts of sulfuric acid, and the sulfur content is usually less than 0.1%, which is negligible; the wastewater from the acid production system is the washing water for purifying acid mist, and has a higher sulfate ion concentration, which is the main channel for sulfur loss.

[0004] The desorption effect of activated carbon in the desorption tower directly determines the quality of activated carbon regeneration and the efficiency of acid production, and further affects the stability of the entire system, which has a two-way feedback mechanism with the operation of the desulfurization and denitrification system. If the desorption is not complete, activated carbon will be left with sulfuric acid and its ammonium salt, causing the micropores to be blocked and the adsorption capacity to decrease, ultimately leading to a decrease in desulfurization and denitrification efficiency. In addition, the more sulfides left on the activated carbon, the less SO2 gas is released, resulting in a decrease in the production of the acid production system and a decrease in the recovery rate of sulfur resources. Furthermore, the accumulation of acidic substances accelerates the pulverization of activated carbon, increases the system resistance, and leads to an increase in operating costs. The desorption effect is a direct representation of the operating state of the desorption tower. When the evaluation result is "poor", it indicates that there are problems such as excessive residual sulfides in the regenerated activated carbon, indicating that the desorption tower has operating defects such as insufficient regeneration temperature, too short residence time, or uneven gas distribution. Through this reverse diagnosis, the process parameters of the desorption tower can be adjusted, such as increasing the regeneration temperature or extending the residence time, to accurately optimize the working conditions of the desorption tower. Therefore, real-time evaluation of the desorption effect not only can predict the performance of the system, but also can provide a scientific basis for closed-loop control of the desorption tower.

[0005] There are several ways to evaluate the desorption effect of activated carbon, such as laboratory testing method (such as fixed bed simulation device), which requires offline setup of a small system to simulate the adsorption-regeneration process, and single test takes several hours, which cannot reflect the actual flue gas fluctuations and the operating state of the industrial equipment. Indirect monitoring method, which only relies on end parameters such as outlet SO2 concentration or denitrification efficiency, cannot quantify the migration path of sulfur elements, and ignores the synergistic relationship between desorption tower regeneration efficiency and acid production system. The existing Chinese patent CN111983131A provides a method for quickly evaluating the regeneration effect of desulfurization and denitrification activated carbon, which shortens the detection time, but has significant defects. It only reflects the decomposition degree of acidic ammonium salt through pH change, and does not cover the total amount of sulfide release (such as sulfur recovery of the acid production system). pH is easily disturbed by factors such as the intrinsic alkalinity of activated carbon and water hardness, and its accuracy is insufficient. The sample needs to be broken, which directly damages the microporous structure of activated carbon and changes its surface chemical properties. Therefore, the existing method cannot comprehensively evaluate the sulfur resource recovery efficiency and cannot provide a basis for system economic optimization. SUMMARY

[0006] The present application aims to provide a method for quickly evaluating the desorption effect of activated carbon for desulfurization and denitrification, based on the quick evaluation method of sulfur mass conservation, aiming to quickly evaluate the desorption effect of activated carbon in the desorption tower (i.e. the regeneration effect after desulfurization and denitrification) to determine whether the desorption is complete. If the desorption effect is not good (P<90%), the operating parameters of the desorption tower need to be adjusted, and if the desorption effect is good (P≥90%), the operating parameters do not need to be adjusted.

[0007] To achieve the above-mentioned purpose, the present application proposes the following technical solutions:

[0008] A rapid evaluation method for desulfurization and denitrification active carbon desorption effect, comprising the following steps:

[0009] S1 obtains the total amount of elemental sulfur M1 adsorbed by the active carbon in the adsorption tower of the desulfurization and denitrification system per unit time;

[0010] S2 obtains the total amount of elemental sulfur M desorbed by the active carbon in the desorption tower of the desulfurization and denitrification system per unit time r ;

[0011] S3 calculates the active carbon desorption effect evaluation parameter P:

[0012] Formula 1:

[0013] S4 outputs the desorption tower control instruction according to the P value.

[0014] As a preferred technical solution of the present application, S1 obtains the total amount of elemental sulfur M1 adsorbed by the active carbon in the adsorption tower of the desulfurization and denitrification system per unit time, comprising:

[0015] Obtain the flue gas inlet flow rate V1 and the flue gas outlet flow rate V2 of the adsorption tower per unit time;

[0016] Obtain the SO2 inlet concentration C1 and the SO2 outlet concentration C2 of the adsorption tower;

[0017] When the relative deviation of V1 and V2 is less than or equal to 5%, the calculation formula of M1 is as follows:

[0018] Formula 2:

[0019] Wherein, M S is the relative atomic mass of sulfur; is the relative molecular mass of SO2; V0 is the average value of V1 and V2,

[0020] As a preferred technical solution of the present application, when the relative deviation of V1 and V2 is greater than 5%, the calculation formula of M1 is as follows:

[0021] Formula 3:

[0022] As a preferred technical solution of the present application, S2 obtains the total amount of elemental sulfur M desorbed by the active carbon in the desorption tower of the desulfurization and denitrification system per unit time r , comprising:

[0023] Obtain the product sulfuric acid production M of the acid making system of the desulfurization and denitrification system per unit time;

[0024] Obtain the tail gas washing wastewater mass flow rate V of the acid making system of the desulfurization and denitrification system per unit time w;

[0025] The elemental sulfur mass M2 in the product sulfuric acid is calculated based on the product sulfuric acid production M;

[0026] The elemental sulfur mass M3 in the tail gas scrubbing wastewater is calculated based on the tail gas scrubbing wastewater mass flow V w The elemental sulfur mass M3 in the tail gas scrubbing wastewater is calculated based on the tail gas scrubbing wastewater mass flow V

[0027] The total amount of elemental sulfur M resolved in the resolving tower per unit time is analyzed r The elemental sulfur mass M2 in the product sulfuric acid is calculated based on the product sulfuric acid production M;

[0028] Formula 4: M r = M2+ M3.

[0029] As a preferred technical solution of the present application, the product sulfuric acid is concentrated sulfuric acid with a mass fraction of 98%, and the elemental sulfur mass M2 is calculated as follows:

[0030] Formula 5:

[0031] Wherein, M S is the relative atomic mass of sulfur; M 硫酸 is the relative molecular mass of H2SO4.

[0032] As a preferred technical solution of the present application, the elemental sulfur mass M3 is the elemental sulfur mass dissolved in the tail gas scrubbing wastewater in the form of sulfate, and the calculation method is as follows:

[0033] Formula 6:

[0034] Wherein, is the sulfate mass concentration in the tail gas scrubbing wastewater; M S is the relative atomic mass of sulfur; is the relative molecular mass of SO4 2- .

[0035] As a preferred technical solution of the present application, the step S4 outputs the resolving tower control instruction according to the P value, comprising:

[0036] When P < 90%, the activated carbon resolving effect is evaluated as poor, and the resolving tower control instruction output includes increasing the resolving tower regeneration temperature or extending the regeneration time;

[0037] When P ≥ 90%, the activated carbon resolving effect is evaluated as good, and the resolving tower control instruction output is to maintain the current resolving tower working parameters.

[0038] From the above technical solutions, the technical solutions provided by the application provide a rapid evaluation method for the desorption effect of activated carbon for desulfurization and denitrification, which is based on the mass conservation principle of sulfur elements, and the ratio of the total amount of adsorbed sulfur (M1) to the total amount of desorbed sulfur (M r ) is quantified Real-time evaluation and regulation of desorption effect are realized. The present application performs sulfur tracking in the whole process, directly quantifies the migration of sulfur elements (adsorption-desorption-recovery), avoids the interference of indirect parameters (such as pH), directly links the desorption tower operation instructions (such as temperature, time, etc.) with the P value, realizes system self-optimization, calculates in seconds based on online monitoring data (such as flue gas flow and SO2 gas concentration), and does not need offline sampling. The prior art needs to crush the sample and measure the pH after standing, which destroys the structure of activated coke, takes several minutes, and the present application does not need destructive operation, but the pH is disturbed by the intrinsic alkalinity of activated coke and water hardness, resulting in distorted evaluation.

[0039] When calculating the amount of sulfur adsorbed by activated carbon, the present application uses different calculation models (formula 2 or formula 3) according to whether the relative deviation of flue gas flow at the inlet and outlet of the adsorption tower exceeds a certain threshold (5%). This design fully considers the objective reality that there may be deviations in the measurement of actual industrial systems, and can accurately calculate the total amount of elemental sulfur adsorbed by activated carbon under different working conditions (small deviation approximation conservation or large deviation needs accurate accounting), significantly improving the reliability of the evaluation parameter P and the robustness of the entire evaluation method in actual application.

[0040] In addition, the parameters (flue gas inlet flow V1, flue gas outlet flow V2, SO2 inlet concentration C1, SO2 outlet concentration C2) involved in the present application are directly obtained from the existing online detection instruments (such as flue gas CEMS, mass flow meter, ion chromatograph, etc.) of the desulfurization and denitrification system and the acid making system, without the need for additional detection equipment, realizing second-level data updating, supporting real-time calculation of desorption rate P, significantly reducing implementation cost; avoiding the shutdown sampling, crushing, standing and other operations of the traditional method, realizing continuous optimization in the whole production cycle.

[0041] It should be understood that all combinations of the aforementioned concepts and additional concepts described in greater detail below can be seen as part of the subject matter of the present disclosure as long as such concepts are not mutually contradictory.

[0042] The aforementioned and other aspects, embodiments, and features of the present teachings can be more fully understood from the following description, taken in conjunction with the accompanying drawings. Other aspects, features, and embodiments of the present application will become apparent upon examining the description and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1The operation flow chart of the rapid evaluation method for the desulfurization and denitrification active carbon analysis effect of the present application. DETAILED DESCRIPTION

[0044] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the described embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without any creative effort fall within the scope of protection of the present application. Unless otherwise defined, the technical terms or scientific terms used herein should have the usual meanings understood by a person of ordinary skill in the art to which the present application belongs.

[0045] The terms "first", "second", and similar terms used in the patent application specification and claims of the present application do not represent any order, quantity or importance, but are only used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular forms "a", "an" or "the" and the like do not represent a quantity limitation, but represent the existence of at least one. The terms "include" or "contain" and the like mean that the elements or objects appearing before "include" or "contain" cover the features, whole, steps, operations, elements and / or components listed after "include" or "contain", and do not exclude the existence or addition of one or more other features, whole, steps, operations, elements, components and / or sets thereof.

[0046] The present application provides a rapid evaluation method for the desulfurization and denitrification active carbon analysis effect, which is based on the existing conventional active carbon desulfurization and denitrification system provided with an adsorption tower, a desorption tower and an acid making system and the like basic systems. The basic process flow is that the active carbon adsorbs the SO2 gas in the flue gas in the adsorption tower, the saturated active carbon enters the desorption tower for desorption and regeneration, the SO2 therein is released at this stage, and is recovered as a sulfur source for the acid making system, and finally the product sulfuric acid is obtained. The core principle of the method is the law of conservation of mass of sulfur element. In the desulfurization and denitrification system, the total amount of sulfur adsorbed by the active carbon per unit time is equal to the total amount of sulfur desorbed from the active carbon + the mass M1 of sulfur remaining in the active carbon C , M1=M r +M C . By calculating the sulfur mass ratio of the system input and output, the desorption effect is directly quantified.

[0047] As shown in Figure 1 , the rapid evaluation method of the present application mainly includes the following steps:

[0048] S1 obtains the total amount of elemental sulfur M1 adsorbed by the active carbon per unit time in the adsorption tower of the desulfurization and denitrification system;

[0049] S2 obtain the total amount of elemental sulfur M that is desorbed per unit time in the desorption tower of the desulfurization and denitrification system r ;

[0050] S3 calculate the desorption effect evaluation parameter P of the activated carbon:

[0051] Formula 1:

[0052] S4 output the desorption tower control instruction according to the P value.

[0053] When P < 90%, the desorption effect evaluation of the activated carbon is "poor", which indicates that the activated carbon is not completely desorbed in the desorption tower, and the activated carbon after desorption still has a lot of residual sulfur (in the form of sulfate, such as ammonium sulfate), which reversely indicates that the working parameters of the desorption tower need to be adjusted, and the desorption tower control instruction output at this time includes increasing the regeneration temperature of the desorption tower, such as increasing to 450 DEG C or more (normally 400 DEG C), or extending the regeneration time, such as extending to 30 min or more.

[0054] When P ≥ 90%, the desorption effect evaluation of the activated carbon is "good", which indicates that the decomposable sulfur such as sulfuric acid and ammonium sulfate in the activated carbon is fully released, the adsorption performance of the activated carbon is well recovered, and the desorption regeneration effect is good, and at this time the current desorption tower parameters can be maintained without adjustment.

[0055] By establishing a working condition self-adaptive model of sulfur mass conservation, the accuracy under complex working conditions is improved; and based on online closed-loop control of the real-time desorption rate P, the hysteresis of traditional offline detection is broken through.

[0056] The implementation of the present application relies on real-time acquisition of the flue gas inlet flow rate V1 and the flue gas outlet flow rate V2 per unit time of the adsorption tower, the SO2 inlet concentration C1 and the SO2 outlet concentration C2 of the adsorption tower. The acquisition of these parameters is realized by using mature online monitoring technology in the art, such as:

[0057] The flue gas flow rate (V1, V2) is measured in real time by a pitot tube differential pressure flowmeter, an ultrasonic flowmeter or a thermal mass flowmeter installed in the flue;

[0058] The SO2 concentration (C1, C2) is monitored in real time by a continuous emission monitoring system (CEMS), which can measure by using standard methods such as non-dispersive infrared method (NDIR) and ultraviolet differential absorption spectroscopy (UV-DOAS), which is a real-time monitoring means standardized in the field of industrial flue gas treatment at present.

[0059] Sulfate ion concentration in an acid-making system Real-time monitoring of the above parameters can be achieved by using online analysis techniques known in the art, such as ion chromatography (IC) for separating sulfate ions in wastewater through anion exchange column, reducing background conductivity by a suppressor, and quantifying by a conductivity detector; ultraviolet fluorescence method for reducing sulfate ions in wastewater to H2S online, reacting with N, N-dimethyl-p-phenylenediamine to generate methylene blue, and measuring fluorescence intensity at 660 nm wavelength. In addition to the above-mentioned monitoring means, the mass flow of product sulfuric acid and the mass flow of wastewater can also be obtained by using existing monitoring means, which will not be described here.

[0060] It should be noted that the above-mentioned monitoring means belongs to the existing technology category and is not the improvement point of the present application.

[0061] In the present application, when obtaining the total amount of elemental sulfur M1 adsorbed by activated carbon in the desulfurization and denitrification system per unit time, the inlet flow rate V1 and the outlet flow rate V2 of flue gas per unit time of the adsorption tower are obtained; the inlet concentration C1 and the outlet concentration C2 of SO2 of the adsorption tower are obtained; and M1 is calculated by the flow rate and the concentration of SO2.

[0062] During the actual operation of the adsorption tower, due to instrument measurement error or possible small leakage of the system, there is usually a certain deviation ΔV between the inlet flue gas flow rate V1 and the outlet flue gas flow rate V2, ΔV = |V1-V2|, and the relative deviation wherein V0 is the average value of V1 and V2. In order to accurately calculate the total amount of elemental sulfur M1 adsorbed by activated carbon and ensure that it accurately reflects the system sulfur input-output balance, the present application uses different calculation formulas according to the size of the flow deviation.

[0063] In the actual calculation process, when the relative deviation ΔV0 between V1 and V2 is ≤5% (this threshold value is a reasonable limit set based on engineering experience, measurement accuracy and actual system operation stability, and of course this threshold value can be appropriately reduced or increased), the calculation formula of M1 is as follows:

[0064] Formula 2:

[0065] wherein M S is the relative atomic mass of sulfur; is the relative molecular mass of SO2; V0 is the average value of V1 and V2 This formula can effectively ensure the calculation efficiency and accuracy within the acceptable deviation range.

[0066] Substituting formula 2 into formula 1 gives:

[0067]

[0068] The above formula is denoted as formula 1-1.

[0069] In the actual operation of the adsorption tower, due to the possibility of small leakage of the adsorption tower system, instrument measurement error, or small volume difference caused by the change of water content in the flue gas, the flue gas inlet flow and the flue gas outlet flow are not necessarily completely equal. If the relative deviation of V1 and V2 is > 5%, it indicates that the flue gas flow deviation of the adsorption tower is significant, and there may be a non-negligible leakage or measurement problem. In order to more accurately track the mass flow of sulfur element, the difference between the inlet total sulfur input and the outlet unadsorbed sulfur output should be strictly calculated, and the calculation formula of M1 is as follows:

[0070] Formula 3:

[0071] This way can effectively overcome the influence of large flow deviation on the calculation result, and ensure the accuracy of M1.

[0072] Substitute formula 3 into formula 1 to get:

[0073]

[0074] The above formula is denoted as formula 1-2.

[0075] The above calculation strategy is aimed at adapting to the actual industrial measurement working condition, maximizing the reliability of the calculation result of M1, and providing a solid foundation for subsequent analysis effect evaluation. When the relative deviation is ≤5%, formula 2 is used, which not only simplifies the calculation, but also can maintain acceptable accuracy. When the relative deviation is > 5%, it indicates that the adsorption tower may have a non-closed condition, and the mass of sulfur brought in by the inlet and the mass of unadsorbed sulfur brought out by the outlet must be calculated respectively, so as to strictly follow the mass conservation of sulfur element and avoid calculation distortion caused by large deviation. Ensure the accuracy of the calculation of M1 under various actual working conditions, so as to ensure the effectiveness of the evaluation parameter P, make the whole rapid evaluation method result reliable, adaptable and robust. Thus, the engineering practicability, rigor and accurate application of the mass conservation principle of the present application scheme are shown.

[0076] However, it needs to be specially pointed out that, since the adsorption tower system is designed to follow strict sealing standards, and the flow monitoring instrument has high precision characteristics, more than 98% of the working conditions in actual industrial operation meet the relative deviation of flue gas inlet flow and outlet flow ≤3%, which is lower than the threshold of 5%. Therefore, the average flow method of formula 2 is the most commonly used and most efficient calculation model of the present evaluation method. Formula 3 (accurate mass balance method) is only used for abnormal working conditions of instrument failure or system leakage, to ensure the rigor of the evaluation logic under extreme scenarios.

[0077] In the present application, the total amount of elemental sulfur M r is obtained indirectly by calculating the mass of sulfur entering the acid making system.

[0078] In the activated carbon desulfurization and denitrification system, the migration of sulfur mainly exists in two forms: adsorption-desorption-acid making path, SO2 in flue gas is adsorbed by activated carbon, and is decomposed into SO2 gas at high temperature in the desorption tower, and then is transported to the acid making system to be converted into sulfuric acid. A small part of sulfur is lost, mainly lost with wastewater discharge, including the following two: one is the condensate water of the desorption tower, the water vapor from the regeneration process is condensed, and the sulfur content is extremely low, mainly because SO2 has been efficiently captured into the acid making system, and the condensate water only contains trace amounts of sulfate, usually less than 0.1%; the second is the tail gas scrubbing wastewater of the acid making system, which is used to purify the residual acid mist and SO2 in the acid making tail gas, and because it directly handles high-concentration sulfur-containing gas, the concentration of sulfate in the wastewater is very high (its mass concentration is often greater than 1000 mg / L), which is the main channel of sulfur loss in the system. Therefore, based on the migration law of sulfur element, the sulfur loss of the condensate water of the desorption tower can be ignored, and the sulfur loss in the tail gas scrubbing wastewater of the acid making system is absolutely dominant, and accurate measurement of the sulfur content is the key to evaluating the desorption effect.

[0079] Therefore, the acid making system unit time product sulfuric acid yield M and the acid making system unit time tail gas scrubbing wastewater mass flow V w are obtained, and the elemental sulfur mass M2 and the elemental sulfur mass M3 are calculated based on the two respectively; and the total amount of elemental sulfur M r desorbed in the desorption tower per unit time is equal to the sum of the elemental sulfur mass M2 of the product sulfuric acid and the elemental sulfur mass M3 of the tail gas scrubbing wastewater, then M r The calculation method of M

[0080] Formula 4: M r = M2+M3.

[0081] By substituting formula 4 into formula 1, formula 1-1 and formula 1-2 respectively,

[0082] Formula 1-3:

[0083] Formula 1-4:

[0084] Formula 1-5:

[0085] The product sulfuric acid produced by the acid making system of the present application is concentrated sulfuric acid with a mass fraction of 98%, and the calculation method of the elemental sulfur mass M2 is as follows:

[0086] Formula 5:

[0087] Wherein, M S is the relative atomic mass of sulfur; M 硫酸The relative molecular mass of H2SO4.

[0088] The elemental sulfur mass M3 is the mass of elemental sulfur in the form of sulfate entering the tail gas scrubbing wastewater of the acid-making system which is not completely recovered, and the calculation method is as follows:

[0089] Formula 6:

[0090] Wherein, is the mass concentration of sulfate; M S is the relative atomic mass of sulfur; is the relative molecular mass of SO4 2- .

[0091] It should be particularly pointed out that the neglect of the loss of sulfur in the waste water of the resolving tower is a reasonable simplification verified by industrial data, and the error is within the engineering tolerance range. If there is a significant increase in the loss of sulfur in the waste water of the resolving tower (such as more than 5%), it needs to be included in the calculation of M3, and this extension is still within the framework of the sulfur mass balance model of the present application. For systems that have configured resolving tower condensate recovery devices, this part of the waste water is recycled, and the sulfur loss is almost zero, so monitoring the waste water of the acid-making system at this time fully meets the design intention of the present model.

[0092] The calculation formulas provided by the present application are all based on the law of conservation of mass of sulfur element, and the mathematical relationship is independent of the units of parameters. All variables in the formula are expressed in dimensionless mathematical symbols to represent their physical meaning (flow, concentration, mass, etc.). Actual calculation needs to be standardized according to the units output by the measuring instrument, which is a common knowledge in the field of chemical process calculation. The unit conversion does not change the mathematical relationship of the formula, and the person skilled in the art can complete it according to the standardization work guide (GB / T 1.1) and other specifications, so it is not described in the formula.

[0093] Example 1 (typical working condition example)

[0094] This embodiment is based on the common working condition in industrial operation, wherein the deviation of the flue gas flow at the inlet and outlet of the adsorption tower is less than 5% (satisfying the applicable condition of formula 2), and the loss of sulfur in the condensate water of the resolving tower accounts for less than 0.5% (meeting the neglect condition). The specific working condition parameters and calculation process are as follows:

[0095] 1) The flue gas flow is the average value V0 of the flue gas inlet flow V1 and the flue gas outlet flow V2 of the adsorption tower, V0 is 1.5 million m 3 / h; the SO2 inlet concentration C1 of the adsorption tower is 800 mg / m 3 , the SO2 outlet concentration C2 is 20 mg / m 3 , the total amount of elemental sulfur M1 entering the adsorption tower and being adsorbed by activated carbon per hour is calculated according to formula 2, and the specific calculation process is as follows:

[0096]

[0097] Among them, the relative atomic mass of S is 32g / mol, and the relative molecular mass of SO2 is 64g / mol.

[0098] 2) The sulfuric acid production M of the acid production system is 1.6 t / h. The mass of elemental sulfur in 98% concentrated sulfuric acid produced per hour is calculated according to Formula 5. The specific calculation process is as follows:

[0099]

[0100] Among them, the relative atomic mass of S is 32g / mol; the relative molecular mass of H2SO4 is 98g / mol.

[0101] 3) Mass flow rate V of tail gas washing wastewater from the acid production system w The flow rate is 2.2t / h, and the sulfate ion concentration in the tail gas washing wastewater is 3500mg / L. Formula 6 is used to calculate the elemental sulfur mass M3 in the tail gas washing wastewater entering the acid production system per hour. The specific calculation process is as follows:

[0102]

[0103] Among them, SO4 2- The relative molecular mass is 96g / mol.

[0104] 4) Calculate the resolution P according to formula 1-3. The specific calculation process is as follows:

[0105]

[0106] It can be seen from this that P is less than 90%, and the activated carbon analysis effect is evaluated as "poor", indicating that the decomposable sulfur in the activated carbon has not been fully released in the analysis tower, and there are still many residual acidic ammonium salts (such as ammonium sulfate) in the activated carbon after analysis. The output instruction is to increase the regeneration temperature of the analysis tower to 450°C or extend the regeneration time by more than 30 minutes.

[0107] Example 2 (Optimized working condition example)

[0108] On the basis of Example 1, the parameters of the desorption tower were adjusted to obtain the results, showing the common operating conditions after the parameters were adjusted. The flue gas flow deviation and sulfur loss conditions were the same as those in Example 1. Formula 2 was applied and the sulfur loss of the desorption condensed water was ignored:

[0109] 1) The average flue gas flow rate V0 is 1.5 million m 3 / h; the SO2 inlet concentration C1 of the adsorption tower is 800 mg / m 3 , SO2 outlet concentration C2 is 18mg / m3 According to formula 2, the mass of elemental sulfur entering the activated carbon system per hour is M1 = 0.5865t / h.

[0110] 2) The hourly sulfuric acid output M of the acid production system is 1.7 t / h. According to Formula 5, the hourly output mass fraction of elemental sulfur in 98% concentrated sulfuric acid is calculated to be M2 = 0.544 t / h.

[0111] 3) Mass flow rate V of tail gas washing wastewater from the acid production system w The mass concentration of sulfate ions in the tail gas washing wastewater is 3500 mg / L. Formula 6 is used to calculate the mass of elemental sulfur in the tail gas washing wastewater entering the acid production system per hour: M3 = 0.00230 t / h.

[0112] 4) According to formula 1-3, the decomposition rate P is calculated to be 93.14%>90%, and the activated carbon decomposition effect is evaluated as "good", indicating that the decomposable sulfur such as sulfuric acid and ammonium sulfate in the activated carbon is fully released, and the activated carbon recovers its adsorption performance. The working parameters of the decomposition tower do not need to be modified, and the instructions are output to maintain the current parameters.

[0113] Example 3 (Low sulfur concentration condition)

[0114] This example shows a common operating condition under low-sulfur flue gas, where the flue gas flow deviation and sulfur loss conditions comply with Formula 2 and the neglect principle.

[0115] 1) The average flue gas flow rate V0 is 1 million m 3 / h; the SO2 inlet concentration C1 of the adsorption tower is 700 mg / m 3 , SO2 outlet concentration C2 is 20mg / m 3 According to formula 2, the mass of elemental sulfur entering the activated carbon system per hour is M1 = 0.34t / h.

[0116] 2) The sulfuric acid production M of the acid production system is 1 t / h per hour. According to Formula 5, the mass fraction of elemental sulfur in concentrated sulfuric acid with a mass fraction of 98% per hour is calculated to be M2 = 0.32 t / h.

[0117] 3) Mass flow rate of tail gas washing wastewater V of acid production system w The mass concentration of sulfate ions in the tail gas washing wastewater is 3000 mg / L. Formula 6 is used to calculate the mass of elemental sulfur in the tail gas washing wastewater entering the acid production system per hour: M3 = 0.00208 t / h.

[0118] 4) According to formula 1-3, the desorption rate P = 94.72% > 90%, the activated carbon desorption effect evaluation is "good", which shows that the decomposable sulfur such as sulfuric acid and ammonium sulfate in the activated carbon is fully released, the activated carbon restores the adsorption performance, and the desorption tower working parameters do not need to be modified.

[0119] Example 4 (abnormal condition example)

[0120] This example simulates the extreme condition (flow deviation > 5%) caused by instrument failure, which requires the use of formula 3, but the loss of desorbed condensate can still be ignored (as it is still negligible).

[0121] Abnormal data: flue gas inlet flow V1 = 1.5 million m 3 / h, flue gas outlet flow V2 = 1.4 million m 3 / h; the relative deviation

[0122] The other data are the same as in Example 1.

[0123] Formula 3 is enabled for calculation, and the specific calculation process is as follows:

[0124]

[0125] M2, M3 are calculated as in Example 1, and M r = 0.5146 (t / h) is obtained, which is substituted into formula 1:

[0126]

[0127] P < 90%, output "improve regeneration temperature" or "extend regeneration time" instructions, and trigger instrument maintenance alarm.

[0128] Those skilled in the art should understand that the unit standardization of parameters in chemical process calculation (such as g→kg, mg / m 3 →kg / m 3 ) is a basic mathematical operation, which does not need to be disclosed in the patent. The "Chemical Engineering Handbook" has clearly stipulated that process calculation needs to convert parameters to a consistent unit system. The standards such as "Thermal Measurement Standard" and "Continuous Monitoring Technology Standard for Flue Gas Emission" have clearly stipulated the unit system of pollutant concentration and flow. The core value of the formula is to reveal the mass balance relationship of sulfur element in the adsorption-desorption-recovery path, and the unit conversion coefficient is only a constant product item in the engineering implementation. Therefore, the unit conversion coefficient is not reflected in the formula, which does not affect the integrity and implementability of the technical scheme.

[0129] While the application has been described by way of example with reference to preferred embodiments, it is to be understood that this application is not limited to the embodiments disclosed, but is intended to cover modifications and variations within the spirit and scope of the application. Therefore, the scope of the application is defined not by the detailed description of the application but by the following claims, wherein reference to an alternative embodiment includes reference to all features describing that embodiment.

Claims

1. A method for rapid evaluation of the analytical effect of activated carbon for desulfurization and denitrification, characterized in that: The following steps are involved: S1 obtains the total amount of elemental sulfur M1 adsorbed per unit time by activated carbon in the adsorption tower of the desulfurization and denitrification system; S2 obtains the total amount of elemental sulfur M decomposed per unit time in the desorption tower of the desulfurization and denitrification system using activated carbon r ; S3 calculates the activated carbon analysis effect evaluation parameter P: Formula 1: S4 outputs the analytical tower control instructions according to the P value.

2. The rapid evaluation method for the analytical effect of activated carbon for desulfurization and denitrification according to claim 1, characterized in that: The S1 obtains the total amount M1 of elemental sulfur adsorbed per unit time by the activated carbon in the adsorption tower of the desulfurization and denitrification system, including: Obtaining the flue gas inlet flow rate V1 and the flue gas outlet flow rate V2 of the adsorption tower per unit time; Obtaining the SO2 inlet concentration C1 and the SO2 outlet concentration C2 of the adsorption tower; When the relative deviation between V1 and V2 is less than or equal to 5%, the calculation formula of M1 is as follows: Formula 2: Among them, M S is the relative atomic mass of sulfur; is the relative molecular mass of SO2; V0 is the average value of V1 and V2, 3. The rapid evaluation method for the analytical effect of activated carbon for desulfurization and denitrification according to claim 2, characterized in that: When the relative deviation between V1 and V2 is greater than 5%, the calculation formula of M1 is as follows: Formula 3:

4. The rapid evaluation method for the analytical effect of activated carbon for desulfurization and denitrification according to claim 1, characterized in that: The S2 obtains the total amount of elemental sulfur M decomposed per unit time in the desorption tower of the desulfurization and denitrification system by the activated carbon. r ,include: Obtain the sulfuric acid output M per unit time of the acid-making system of the desulfurization and denitrification system; Get the tail gas washing wastewater mass flow rate V per unit time of the acid making system of the desulfurization and denitrification system w ; Calculate the elemental sulfur mass M2 based on the sulfuric acid output M of the product; Based on the tail gas washing wastewater mass flow V w Calculate the mass of elemental sulfur M3; The total amount of elemental sulfur M analyzed per unit time in the analysis tower r It is equal to the sum of the elemental sulfur mass M2 of the product sulfuric acid and the elemental sulfur mass M3 of the tail gas washing wastewater, and is calculated as follows: Formula 4: M r =M2+M3.

5. The rapid evaluation method for the analytical effect of activated carbon for desulfurization and denitrification according to claim 4, characterized in that: The product sulfuric acid is concentrated sulfuric acid with a mass fraction of 98%. The calculation method of the elemental sulfur mass M2 is as follows: Formula 5: Among them, M S is the relative atomic mass of sulfur; M 硫酸 is the relative molecular mass of H2SO4.

6. The rapid evaluation method for the analytical effect of activated carbon for desulfurization and denitrification according to claim 4, characterized in that: The elemental sulfur mass M3 is the mass of elemental sulfur dissolved in the tail gas scrubbing wastewater in the form of sulfate ions, and its calculation method is as follows; Formula 6: in, M is the mass concentration of sulfate in the tail gas washing wastewater; S is the relative atomic mass of sulfur; SO4 2- The relative molecular mass.

7. The rapid evaluation method for the analytical effect of activated carbon for desulfurization and denitrification according to claim 1, characterized in that: The step S4 outputs the analytical tower control instruction according to the P value, including: When P is less than 90%, the activated carbon decomposition effect is evaluated as poor, and the decomposition tower control instructions are output, including increasing the decomposition tower regeneration temperature or extending the regeneration time; When P≥90%, the activated carbon analysis effect is evaluated as good, and the output analysis tower control instruction is to maintain the current analysis tower working parameters.

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