Flue gas desulfurization and denitrification purification treatment system

Abstract

The invention discloses a flue gas desulfurization and denitrification purification treatment system, the flue gas desulfurization and denitrification purification treatment system comprises an adsorption tower, a regeneration tower and a reaction tower, the adsorption tower is internally provided with an adsorbent, so that flue gas enters the adsorption tower, sulfur oxides and nitrogen oxides in the flue gas are adsorbed and removed by using the adsorbent, the regeneration tower is connected with the adsorption tower, and the reaction tower is connected with the adsorption tower. The reaction tower is connected with the regeneration tower, so that regenerated gas desorbed and regenerated by the regeneration tower enters the reaction tower for salt production, and part of tail gas generated by salt production of the reaction tower enters the regeneration tower so as to carry the regenerated gas to flow out of the regeneration tower. Part of salt manufacturing tail gas is used as shielding gas to replace nitrogen, so that the usage amount of the nitrogen in the regeneration tower is reduced, and the operation cost and the initial investment of the system are reduced. And moreover, the salt-making tail gas is rich in pollutants, so that the concentration of the pollutants in the regenerated gas can be effectively improved, and the salt-making reaction in the subsequent reaction tower is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of flue gas purification, and in particular to a flue gas desulfurization and denitrification purification treatment system. Background Art

[0002] With the increasingly stringent environmental protection policies, higher requirements are put forward for the emission control of sulfur oxides (SOx) and nitrogen oxides (NOx) in flue gas. As an efficient flue gas purification method, activated coke / carbon desulfurization and denitrification technology has been widely used in many industrial fields. However, in the process of activated coke / carbon desulfurization and denitrification, the saturated adsorbent in the adsorption tower needs to be transported to the regeneration tower for regeneration.

[0003] In the related art, the temperature of the regeneration tower is relatively high (about 350°C), which easily leads to spontaneous combustion of the adsorbent. In order to prevent spontaneous combustion, nitrogen needs to be filled into the regeneration tower for sealing and isolating from the air. At the same time, nitrogen also serves as a carrier gas to promptly take away the pollutant-rich gas that has been resolved. However, during the regeneration process, a large amount of nitrogen is required as a seal and carrier gas, which increases the operating cost and initial investment of the system. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, an embodiment of the present invention proposes a flue gas desulfurization and denitrification purification treatment system to solve the problem of high cost in related technologies.

[0006] The flue gas desulfurization and denitrification purification treatment system of the embodiment of the present invention comprises:

[0007] An adsorption tower, wherein the adsorption tower has an adsorbent, so that the flue gas enters the adsorption tower and the sulfur oxides and nitrogen oxides in the flue gas are adsorbed and removed by the adsorbent;

[0008] A regeneration tower, the regeneration tower is connected to the adsorption tower, so that the adsorbent saturated with adsorption enters the regeneration tower for analytical regeneration;

[0009] The reaction tower is connected to the regeneration tower so that the regeneration gas generated by the analysis and regeneration of the regeneration tower enters the reaction tower for salt production, and part of the tail gas generated by the salt production of the reaction tower enters the regeneration tower to carry the regeneration gas out of the regeneration tower.

[0010] The flue gas desulfurization and denitrification purification treatment system of the embodiment of the present invention uses part of the salt production tail gas as a protective gas to replace nitrogen, thereby reducing the amount of nitrogen used in the regeneration tower, reducing the operating cost and initial investment of the system. In addition, the salt production tail gas is rich in pollutants, which can effectively increase the concentration of pollutants in the regeneration gas, which is beneficial to the subsequent salt production reaction in the reaction tower.

[0011] In some embodiments, the regeneration tower has a regeneration gas outlet and a protective gas inlet. The regeneration gas outlet of the regeneration tower is connected to the inlet of the reaction tower via a pipeline so that the regeneration gas is transported to the reaction tower through the pipeline. The outlet of the reaction tower is connected to the protective gas inlet of the regeneration tower via a pipeline so that the salt-making tail gas is transported to the regeneration tower through the pipeline.

[0012] In some embodiments, the regeneration gas outlet of the regeneration tower is located in the middle of the regeneration tower.

[0013] In some embodiments, the protective gas inlet of the regeneration tower includes a first protective gas inlet and a second protective gas inlet, the first protective gas inlet of the regeneration tower is connected to the outlet of the reaction tower via a pipeline, and the second protective gas inlet of the regeneration tower is connected to a nitrogen source via a pipeline.

[0014] In some embodiments, the first protective gas inlet of the regeneration tower is located at the upper part of the regeneration tower, and the second protective gas inlet of the regeneration tower is located at the lower part of the regeneration tower.

[0015] In some embodiments, a washing tower is also included, wherein the inlet of the washing tower is connected to the regeneration gas outlet of the regeneration tower via a pipeline, and the outlet of the washing tower is connected to the inlet of the reaction tower via a pipeline, so that the regeneration gas is washed by the washing tower to remove dust and then sent to the reaction tower for salt production.

[0016] In some embodiments, an induced draft fan is provided on the pipeline between the regeneration gas outlet of the regeneration tower and the inlet of the washing tower.

[0017] In some embodiments, the outlet of the reaction tower is also connected to the boiler via a pipeline, so that a portion of the salt-making tail gas is sent to the regeneration tower, and the other portion of the salt-making tail gas is returned to the furnace for combustion.

[0018] In some embodiments, the adsorption tower and the regeneration tower both have an adsorbent inlet and an adsorbent outlet. The adsorbent outlet of the adsorption tower is connected to the adsorbent inlet of the regeneration tower via a pipeline so that the adsorbent saturated with adsorption is transported to the regeneration tower for decomposition and regeneration. The adsorbent outlet of the regeneration tower is connected to the adsorbent inlet of the adsorption tower via a pipeline so that the decomposition and regeneration adsorbent is transported back to the adsorption tower to adsorb flue gas.

[0019] In some embodiments, the environment for flue gas adsorption and purification in the adsorption tower is below zero degrees. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of a flue gas desulfurization and denitrification purification treatment system according to an embodiment of the present invention.

[0021] Reference numerals:

[0022] 1-adsorption tower, 2-regeneration tower, 201-regeneration gas outlet, 202-first protective gas inlet, 203-second protective gas inlet, 3-reaction tower, 4-washing tower, 5-induced draft fan. DETAILED DESCRIPTION

[0023] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0024] The following describes a flue gas desulfurization and denitrification purification treatment system according to an embodiment of the present invention in conjunction with the accompanying drawings.

[0025] like Figure 1 As shown, the flue gas desulfurization and denitrification purification treatment system according to the embodiment of the present invention comprises: an adsorption tower 1 , a regeneration tower 2 and a reaction tower 3 .

[0026] The adsorption tower 1 contains an adsorbent. The flue gas generated by the combustion of the boiler enters the adsorption tower 1, and the adsorbent is used to adsorb and remove sulfur oxides and nitrogen oxides in the flue gas, thereby achieving the purpose of purifying the flue gas.

[0027] It should be noted that the environment for flue gas adsorption and purification in the adsorption tower 1 is below zero degrees. In the low temperature environment of the sub-zero temperature zone, the nitrogen oxides in the flue gas undergo low-temperature oxidation adsorption on the surface of adsorbents such as activated carbon, oxidizing the difficult-to-adsorb nitric oxide gas into easily adsorbed nitrogen dioxide gas, achieving a hundreds-fold increase in adsorption capacity. In addition, the adsorption capacity of components such as sulfur dioxide, carbon dioxide and heavy metals is also multiplied in a low temperature environment.

[0028] For example, before the flue gas enters the adsorption tower 1, it is first spray-cooled through a spray tower to cool the flue gas to a sub-zero temperature range.

[0029] The regeneration tower 2 is connected to the adsorption tower 1. The adsorbent will reach a saturated state after adsorbing the flue gas. The saturated adsorbent enters the regeneration tower 2 for analytical regeneration.

[0030] The reaction tower 3 is connected to the regeneration tower 2. The regeneration gas generated by the analysis of the regeneration tower 2 enters the reaction tower 3 for salt production. Among them, the reaction tower 3 is the core equipment of the salt production workshop. The regeneration gas is used to prepare products such as sodium sulfate and sodium pyrosulfite, and to recover sulfur resources in the rich gas.

[0031] A tail gas produced by the salt production in the reaction tower 3 is introduced into the regeneration tower 2 to replace nitrogen to seal the regeneration tower 2 and act as a carrier gas.

[0032] Therefore, the flue gas desulfurization and denitrification purification treatment system of the embodiment of the present invention uses part of the salt production tail gas as a protective gas to replace nitrogen, thereby reducing the nitrogen usage in the regeneration tower 2 by 50%, reducing the operating cost and initial investment of the system. In addition, the salt production tail gas is rich in pollutants, which can effectively increase the concentration of pollutants in the regeneration gas, which is beneficial to the subsequent salt production reaction in the reaction tower 3.

[0033] In some embodiments, Figure 1 As shown, the regeneration tower 2 has a regeneration gas outlet 201 and a protective gas inlet, and the regeneration gas outlet 201 of the regeneration tower 2 is connected to the inlet of the reaction tower 3 through a pipeline, so that the regeneration gas is transported to the reaction tower 3 through the pipeline. The outlet of the reaction tower 3 is connected to the protective gas inlet of the regeneration tower 2 through a pipeline, so that the salt-making tail gas is transported to the regeneration tower 2 through the pipeline.

[0034] It is understandable that the salt-making tail gas rich in water can be used as a protective gas to be filled into the regeneration tower 2 to prevent the adsorbent from spontaneous combustion, and at the same time serve as a carrier gas to carry away the pollutants analyzed during the regeneration process.

[0035] The salt production tail gas is transported to the protective gas inlet of the regeneration tower 2 through a pipeline, filled into the tower, mixed with the regeneration gas, and then discharged together into the reaction tower 3. The entire process ensures a closed cycle of the system, reduces gas emissions, and also improves resource utilization.

[0036] Alternatively, if Figure 1 As shown, the regeneration gas outlet 201 of the regeneration tower 2 is located in the middle of the regeneration tower 2 .

[0037] It should be noted that the regeneration tower 2 is divided into a preheating section, a heating section and a cooling section from top to bottom, and the middle part of the regeneration tower 2 is mainly used for heating the desorbent, that is, the regeneration gas is mostly generated in the middle part of the regeneration tower 2. Therefore, the regeneration gas outlet 201 is opened in the middle part of the regeneration tower 2 to facilitate the regeneration gas to flow out of the regeneration tower 2.

[0038] In some embodiments, Figure 1 As shown, the protective gas inlet of the regeneration tower 2 includes a first protective gas inlet 202 and a second protective gas inlet 203. The first protective gas inlet 202 of the regeneration tower 2 is connected to the outlet of the reaction tower 3 via a pipeline, and the second protective gas inlet 203 of the regeneration tower 2 is connected to the nitrogen source via a pipeline.

[0039] It is understandable that the components of the salt production tail gas may include water vapor, salt mist, possible organic matter and a small amount of unreacted chemicals. These components may affect the reaction environment in the regeneration tower 2. Nitrogen, as an inert gas, can provide a more stable gas environment and help to accurately control the regeneration process.

[0040] Although the inactive gases contained in the salt production tail gas can provide some protection, they are not enough to completely isolate oxygen and prevent the adsorbent from spontaneous combustion. The addition of nitrogen can provide additional protection to ensure that the adsorbent will not spontaneously combust in a high temperature environment.

[0041] The flow rate and composition of the salt production tail gas may fluctuate due to different production processes, which may affect the operational stability of the regeneration tower 2. The addition of nitrogen can help maintain a relatively stable environment.

[0042] Furthermore, if Figure 1 As shown, the first protective gas inlet 202 of the regeneration tower 2 is located at the upper part of the regeneration tower 2, and the second protective gas inlet 203 of the regeneration tower 2 is located at the lower part of the regeneration tower 2. The salt-making tail gas enters the regeneration tower 2 from the upper part of the regeneration tower 2 and flows to the middle part of the regeneration tower 2, and the nitrogen enters the regeneration tower 2 from the lower part of the regeneration tower 2 and flows to the middle part of the regeneration tower 2.

[0043] It is understandable that the lower part of the regeneration tower 2 is the adsorbent after analytical regeneration. Since the sulfur resources in the regeneration gas are recovered by salt production, nitrogen oxides are still present in the regeneration gas. Therefore, it is prevented that the salt production tail gas enters from the lower part and causes adsorbent contamination. The upper adsorbent itself is already saturated with adsorption, so this problem does not exist, thereby improving the rationality of salt production tail gas reuse.

[0044] In some embodiments, Figure 1 As shown, a washing tower 4 is also included between the regeneration tower 2 and the reaction tower 3. The inlet of the washing tower 4 is connected to the regeneration gas outlet 201 of the regeneration tower 2 through a pipeline, and the outlet of the washing tower 4 is connected to the inlet of the reaction tower 3 through a pipeline, so that the regeneration gas can be washed by the washing tower 4 to remove dust and then sent to the reaction tower 3 for salt production.

[0045] It is understandable that the purpose of washing the regenerated gas before making salt from it is to ensure a smooth salt making process and to improve product quality.

[0046] Regeneration gas contains dust, unreacted chemicals and other impurities. These impurities can be removed by scrubbing to prevent them from forming precipitation in the salt production process or affecting the purity and quality of the salt.

[0047] In addition, dust and other solid particles may clog or wear pipes, pumps and other equipment, causing unstable system operation or even equipment damage. Washing can reduce the content of these particles and extend the life of the equipment.

[0048] In some embodiments, an induced draft fan 5 is provided on the pipeline between the regeneration gas outlet 201 of the regeneration tower 2 and the inlet of the washing tower 4 .

[0049] It is understandable that the induced draft fan 5 can help overcome the resistance in the system and increase the flow rate of the gas, thereby improving the flow efficiency of the regenerated gas from the regeneration tower 2 to the washing tower 4. Through the suction effect of the induced draft fan 5, the pressure difference between the regeneration tower 2 and the washing tower 4 can be adjusted to ensure that the system operates at an appropriate pressure and avoid equipment damage or unstable operation caused by excessively high or low pressure.

[0050] In some embodiments, Figure 1 As shown, the outlet of the reaction tower 3 is also connected to the boiler (not shown) through a pipeline, so that a part of the salt-making tail gas is sent to the regeneration tower 2, and the other part of the salt-making tail gas is returned to the furnace for combustion.

[0051] It should be noted that the nitrogen oxides in the tail gas of salt production can act as an oxidant, which helps the boiler to burn completely, thereby improving the combustion efficiency of the boiler. Therefore, the nitrogen oxides in the tail gas of salt production are returned to the furnace for combustion to achieve the final treatment and resource utilization of nitrogen oxides.

[0052] In some embodiments, Figure 1 As shown, both the adsorption tower 1 and the regeneration tower 2 have an adsorbent inlet and an adsorbent outlet.

[0053] The adsorbent outlet of adsorption tower 1 is connected to the adsorbent inlet of regeneration tower 2 via a pipeline, so that the adsorbent saturated with adsorption is transported to regeneration tower 2 for decomposition and regeneration. The adsorbent outlet of regeneration tower 2 is connected to the adsorbent inlet of adsorption tower 1 via a pipeline, so that the decomposition and regeneration adsorbent is transported back to adsorption tower 1 to adsorb flue gas.

[0054] It is understandable that after the adsorbent adsorbs pollutants in the adsorption tower 1, it can restore its adsorption capacity by circulating to the regeneration tower 2 for regeneration. This recycling can ensure that the adsorbent always maintains a high adsorption efficiency and prolongs the service life of the adsorbent.

[0055] The circulation of the adsorbent means that the same adsorbent can be reused, which reduces the consumption of the adsorbent, reduces costs, and is also beneficial to the environment. Through the regeneration process, the pollutants in the adsorbent are analyzed and transferred to the regenerated rich gas, which can reduce the generation of solid waste and reduce the cost of waste treatment.

[0056] The circulating adsorbent can provide a continuous and stable adsorption-regeneration process, which helps to maintain the stability of system operation. By controlling the flow rate and residence time of the adsorbent between the adsorption tower 1 and the regeneration tower 2, the operating parameters of the system can be flexibly adjusted to adapt to different working conditions and loads.

[0057] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0058] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0059] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0060] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0061] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0062] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A flue gas desulfurization and denitrification purification treatment system, characterized in that: include: An adsorption tower, wherein the adsorption tower has an adsorbent, so that the flue gas enters the adsorption tower and the sulfur oxides and nitrogen oxides in the flue gas are adsorbed and removed by the adsorbent; A regeneration tower, the regeneration tower is connected to the adsorption tower, so that the adsorbent saturated with adsorption enters the regeneration tower for analytical regeneration; The reaction tower is connected to the regeneration tower so that the regeneration gas generated by the analysis and regeneration of the regeneration tower enters the reaction tower for salt production, and part of the tail gas generated by the salt production of the reaction tower enters the regeneration tower to carry the regeneration gas out of the regeneration tower.

2. The flue gas desulfurization and denitrification purification treatment system according to claim 1, characterized in that: The regeneration tower has a regeneration gas outlet and a protective gas inlet. The regeneration gas outlet of the regeneration tower is connected to the inlet of the reaction tower via a pipeline, so that the regeneration gas is transported to the reaction tower through the pipeline. The outlet of the reaction tower is connected to the protective gas inlet of the regeneration tower via a pipeline, so that the salt-making tail gas is transported to the regeneration tower through the pipeline.

3. The flue gas desulfurization and denitrification purification treatment system according to claim 2 is characterized in that: The regeneration gas outlet of the regeneration tower is located in the middle of the regeneration tower.

4. The flue gas desulfurization and denitrification purification treatment system according to claim 3 is characterized in that: The protective gas inlet of the regeneration tower comprises a first protective gas inlet and a second protective gas inlet. The first protective gas inlet of the regeneration tower is connected to the outlet of the reaction tower via a pipeline, and the second protective gas inlet of the regeneration tower is connected to a nitrogen source via a pipeline.

5. The flue gas desulfurization and denitrification purification treatment system according to claim 4, characterized in that: The first protective gas inlet of the regeneration tower is located at the upper part of the regeneration tower, and the second protective gas inlet of the regeneration tower is located at the lower part of the regeneration tower.

6. The flue gas desulfurization and denitrification purification treatment system according to claim 2, characterized in that: It also includes a washing tower, the inlet of which is connected to the regeneration gas outlet of the regeneration tower via a pipeline, and the outlet of which is connected to the inlet of the reaction tower via a pipeline, so that the regeneration gas is washed by the washing tower to remove dust and then sent to the reaction tower for salt production.

7. The flue gas desulfurization and denitrification purification treatment system according to claim 6, characterized in that: An induced draft fan is provided on the pipeline between the regeneration gas outlet of the regeneration tower and the inlet of the washing tower.

8. The flue gas desulfurization and denitrification purification treatment system according to claim 4, characterized in that: The outlet of the reaction tower is also connected to the boiler via a pipeline, so that a part of the salt-making tail gas is sent to the regeneration tower, and the other part of the salt-making tail gas is returned to the furnace for combustion.

9. The flue gas desulfurization and denitrification purification treatment system according to any one of claims 1 to 8, characterized in that: The adsorption tower and the regeneration tower both have an adsorbent inlet and an adsorbent outlet. The adsorbent outlet of the adsorption tower is connected with the adsorbent inlet of the regeneration tower via a pipeline so that the adsorbent saturated with adsorption is transported to the regeneration tower for decomposition and regeneration. The adsorbent outlet of the regeneration tower is connected with the adsorbent inlet of the adsorption tower via a pipeline so that the decomposition and regeneration adsorbent is transported back to the adsorption tower to adsorb flue gas.

10. The flue gas desulfurization and denitrification purification treatment system according to any one of claims 1 to 8, characterized in that: The environment for flue gas adsorption and purification in the adsorption tower is below zero degrees.

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