WO2018000888A1

WO2018000888A1 - Flue gas desulfurization and denitrification method and device capable of preventing corrosion

Info

Publication number: WO2018000888A1
Application number: PCT/CN2017/080044
Authority: WO
Inventors: 刘昌齐; 彭建宏; 魏进超; 叶恒棣; 李勇
Original assignee: 中冶长天国际工程有限责任公司; 湖南中冶长天节能环保技术有限公司
Priority date: 2016-06-30
Filing date: 2017-04-11
Publication date: 2018-01-04
Also published as: CN107551756A

Abstract

A flue gas desulfurization and denitrification method and device. The device comprises an adsorption tower (T1) and an activated carbon regeneration tower (T3). An acid gas conveying pipeline (L3a) of the activated carbon regeneration tower (T3) is preheated by using heating gas of the activated carbon regeneration tower (T3), and the acid gas conveying pipeline (L3a) is purged after the regeneration operation is ended, so as to prevent the acid gas conveying pipeline (L3a) from being corroded.

Description

Flue gas desulfurization and denitration method and device for preventing corrosion

This application claims the priority of the invention patent application filed on June 30, 2016, the Chinese Patent Office, the application number is 201610507677.3, and the invention is entitled "Fouling and Desulfurization Denitration Method and Device for Corrosion Prevention", the entire contents of which are incorporated herein by reference. In the application.

Technical field

The invention relates to a flue gas desulfurization and denitration device using activated carbon and a flue gas desulfurization and denitration method. More particularly, the present invention relates to a flue gas desulfurization and denitration apparatus in which an acid gas delivery pipe of an activated carbon desorption column is preheated by using a heating gas and an acid gas delivery pipe is purged after the end of the resolving operation to prevent the Pipeline corrosion, these are in the field of flue gas treatment.

Background technique

The activated carbon process for flue gas technology has been used for more than 50 years. The early technical research and application are mainly concentrated in Germany, Japan, the United States and other countries. Germany's BF Company began to develop Reinluft desulfurization technology in 1957 (now DMT Company), Japan began to study activated carbon desulfurization in the mid-1960s, and Germany's Luqi Company also carried out water washing and regeneration activated carbon flue gas desulfurization earlier. Process research. With the development and maturity of activated carbon flue gas desulfurization technology abroad, some representative ones such as German BF method, Reinluft method and Lurgi method; Japan's Japanese legislation, Sumitomo law; and US Westraco method have been produced.

For industrial flue gas, especially for the sintering machine flue gas of the steel industry, it is desirable to use a desulfurization and denitration device and a process including an activated carbon adsorption tower and an analytical column. In a desulfurization and denitration device including an activated carbon adsorption tower and an analytical tower (or a regeneration tower), an activated carbon adsorption tower is used for adsorbing sulfur oxides and nitrogen from sintering flue gas or exhaust gas (especially sintering flue gas of a sintering machine of the steel industry). Contaminants such as oxides, dust and dioxins, and analytical towers for thermal regeneration of activated carbon.

Activated carbon desulfurization has the advantages of high desulfurization rate, simultaneous denitrification, deodorization, dust removal, and no waste water residue. It is a promising method for flue gas purification. Activated carbon can be regenerated at high temperatures. At temperatures above 350 °C, pollutants such as sulfur oxides, nitrogen oxides, and dioxins adsorbed on activated carbon are rapidly resolved or decomposed (sulphur dioxide is analyzed, nitrogen oxides and dioxins). English is broken down). And as the temperature increases, the regeneration rate of activated carbon is further accelerated, and the regeneration time is shortened. It is preferred that the regeneration temperature of the activated carbon in the general control analytical tower is approximately equal to 430 ° C. Therefore, The desired resolution temperature (or regeneration temperature) is, for example, in the range of 390 to 450 ° C, more preferably in the range of 400 to 440 ° C.

The traditional activated carbon desulfurization process is shown in Figure 1. The flue gas is introduced into the adsorption tower by the booster fan, and a mixed gas of ammonia gas and air is injected into the inlet port to improve the NOx removal efficiency, and the purified flue gas enters the sintering main chimney to discharge. The activated carbon is added to the adsorption tower from the top of the column and moves downward by gravity and the bottom discharge device. The activated carbon from the analytical tower is transported to the adsorption tower by the activated carbon conveyor. The activated carbon adsorbed by the adsorption tower is discharged from the bottom, and the discharged activated carbon is transported by the activated carbon conveyor to the analytical tower for regeneration of the activated carbon.

Activated carbon flue gas purification technology has the characteristics of simultaneous desulfurization and denitrification, resource utilization of by-products, recyclability of adsorbents, high efficiency of desulfurization and denitrification, and is a promising technology for desulfurization and denitrification. In a desulfurization and denitration device including an activated carbon adsorption tower and an analytical tower (or a regeneration tower), an activated carbon adsorption tower is used for adsorbing sulfur oxides and nitrogen from sintering flue gas or exhaust gas (especially sintering flue gas of a sintering machine of the steel industry). Contaminants such as oxides and dioxins, and analytical towers for thermal regeneration of activated carbon.

Activated carbon method flue gas purification technology has the function of simultaneous desulfurization and denitrification. The main equipment included in this process includes adsorption tower, regeneration tower and activated carbon conveying device. Compared with NOx, SO ₂ is easier to remove. Under normal circumstances, a group of adsorption towers can obtain a desulfurization rate of up to 90%, but the denitration rate is low.

Generally, the activated carbon method flue gas purification technology has the characteristics of high desulfurization and denitrification rate, resource utilization of by-products, and recycling of activated carbon. The principle of desulfurization and denitrification is as follows:

In the adsorption tower, a part of the SO ₂ in the flue gas is adsorbed by the activated carbon, but another part of the SO ₂ , that is, the surface of the activated carbon, SO ₂ is oxidized and absorbed to form sulfuric acid, and its reaction formula:

2SO ₂ +O ₂ +2H ₂ O→2H ₂ SO ₄

If a small amount of ammonia is sprayed into the flue gas or in the adsorption tower, the absorption of SO ₂ can be accelerated, and its reaction formula:

NH ₃ +H ₂ SO ₄ →NH ₄ HSO ₄

However, in order to achieve the effect of denitration at the same time of desulfurization, a large amount of ammonia is generally injected at the inlet of the adsorption tower flue gas, which satisfies both the ammonia required for desulfurization and the ammonia required for denitration. The denitration reaction formula is:

4NO+O ₂ +4NH ₃ →4N ₂ +6H ₂ O

At the same time, the following side reactions exist in the adsorption tower:

2NH ₃ +H ₂ SO ₄ →(NH ₄ ) ₂ SO ₄ .

In general, the reaction rate of SO ₂ with NH ₃ is faster than the reaction rate of NO with NH ₃ . In addition, SO ₃ , HF, and HCl in the flue gas also react with NH ₃ .

The function of the analytical tower is to release the SO ₂ adsorbed by the activated carbon. At the same temperature and a certain residence time of 400 ° C, the dioxins can be decomposed by more than 80%, and the activated carbon is re-used after being cooled and sieved. The released SO ₂ can be made into sulfuric acid or the like, and the analyzed activated carbon is sent to the adsorption tower through a transfer device to be used for adsorbing SO ₂ and NO _X .

In the adsorption tower with the analytical column with ammonia in the NO _X occurs SCR, SNCR reactions, thereby removing the NO _X. The dust is adsorbed by the activated carbon when passing through the adsorption tower, and the vibrating screen at the bottom end of the analytical tower is separated, and the activated carbon powder under the sieve is sent to the ash silo, which can then be sent to the blast furnace or sintered for use as a fuel.

The activated carbon method is used for purifying the flue gas, and in order to improve the purifying effect, the flue gas can be passed through the multi-layer activated carbon bed. The multi-layer activated carbon bed layout is mainly divided into upper and lower structures and front and rear structures, as shown in FIG. 2 . The activated carbon bed in the tower is a whole, and the activated carbon is uniformly moved downward by gravity. Following the flow direction of the flue gas, the activated carbon in contact with the flue gas first adsorbs more pollutants in the flue gas, and is discharged together with the activated carbon, which will cause the activated carbon to be discharged into the tower without being adsorbed and saturated, or the activated carbon is saturated in the front. There is no smoke purification effect inside the tower.

The iron and steel industry has made important contributions to promoting the development of China's industrialization and urbanization. At the same time, China's steel industry has a low level of environmental protection and high emissions per unit of output, which has seriously restricted the overall competitiveness of the steel industry. In order to control pollutant emissions, the Ministry of Environmental Protection has formulated the "Steel Sintering and Pellet Industry Air Pollutant Emission Standards", stating that since January 1, 2015, existing steel companies have sintered and pellets to implement the following atmospheric pollutant emission limits. : SO ₂ 200 mg/m ³ , NOx 300 mg/m ³ , dioxins 0.5 ng-TEG/m ³ . It can be seen that the air pollution control in the steel industry has been upgraded from the original dust removal and desulfurization to the coordinated control of multi-pollutants such as SO ₂ -NOx-dioxin. At present, domestic desulfurization technology is maturing, and denitrification and dioxins are still in their infancy. Domestic Shanghai Keshi Company has adopted active coke technology in coal-fired boilers and non-ferrous smelting industry, and its structural form and principle are consistent with Sumitomo.

Activated carbon (coke) sintering flue gas purification technology is a resource-based dry flue gas treatment technology, which has water-saving, desulfurization, denitrification, deodorization, de-lifting metals, dust removal and removal of other trace harmful flue gas components ( The functions of HCl, HF, SO _{3 ,} etc., can also recover sulfur resources that are scarce in China (high concentration of SO ₂ can produce concentrated sulfuric acid, etc.).

Figure 2 shows the activated carbon adsorption unit of Sumitomo Corporation of Japan: the activated carbon bed in the tower is divided into three In each chamber, the activated carbon in each chamber is uniformly moved downward by gravity. According to the flow direction of the flue gas, the activated carbon in the front chamber which is first contacted with the flue gas adsorbs more pollutants in the flue gas, and the activated carbon in the middle and rear chambers sequentially adsorbs the flue gas. The pollutants, thereby controlling the rotation speed of the discharge valve at the bottom of the activated carbon bed to control the discharge speed of the activated carbon, thereby achieving the effect of purifying the flue gas.

Figure 3 shows the activated carbon adsorption unit of Shanghai Keshi Company: the activated carbon bed in the tower is a whole, and the multi-stage activated carbon bed layout is mainly divided into upper and lower structures, and the activated carbon is uniformly moved downward by gravity. Following the flow direction of the flue gas, the activated carbon in contact with the flue gas first adsorbs more pollutants in the flue gas, and is discharged together with the activated carbon, which will cause the activated carbon to be discharged into the tower without being adsorbed and saturated, or the activated carbon is saturated in the front. There is no smoke purification effect inside the tower.

Since the concentration of harmful components in the flue gas gradually increases from the top to the bottom after the original flue gas enters the adsorption tower through the adsorption tower, the existing processes and devices need to transfer all the flue gas into the next-stage adsorption tower, which not only increases the investment and Operating costs also add additional equipment maintenance effort.

In order to save investment and operating costs, a more rational activated carbon purification process and equipment is required.

Summary of the invention

In view of the above drawbacks and problems, the inventors of the present application have found through intensive research that the concentration of pollutants in the flue gas (referred to as the upper layer flue gas) entering the gas outlet from the middle and upper portions of the activated carbon bed of the adsorption tower is very low (ppm). Level), often meet emission requirements or emission standards, or the flue gas in this part is treated separately.

The invention aims at purifying the environmental protection requirements of flue gas purification requirements, purifying the flue gas, and must reach the higher requirements, and must perform secondary treatment on all flue gases. The technology is based on the fact that the flue gas component is gradually increased from top to bottom after the first treatment of the flue gas purification device (because the activated carbon (coke) entering the upper part of the purification device is activated carbon (focal) activated by the analytical tower, When the activated carbon (coke) moves from top to bottom, the adsorption of activated carbon (coke) on the harmful components of the flue gas increases, and the adsorption capacity is weaker, so that the concentration of the harmful components that emit the flue gas is higher. Therefore, part of the flue gas in which the harmful components exceed the standard is extracted into the secondary flue gas purification device or returned to the first-stage adsorption tower, and part of the flue gas that meets the discharge requirement after the first-stage treatment is directly discharged into the atmosphere through the chimney.

The process and device of the invention divides the gas outlet chamber of the adsorption tower into two layers or a plurality of layers, and adjusts the amount of smoke entering the adsorption tower of the next stage according to the concentration of harmful components of the exhausted smoke, so that the next stage is entered. The amount of flue gas will be reduced by 30% to 50%, which can reduce the capacity of the booster fan and the secondary adsorption tower, thereby reducing investment and operating costs. In the prior art, the clean flue gas in the upper part of the air outlet chamber and the flue gas containing the contaminant in the lower part are avoided.

During the process of the flue gas entering the adsorption tower passing through the activated carbon bed, the harmful components in the flue gas are purified. Since the activated carbon in the adsorption tower is from top to bottom, the upper part is activated carbon with strong adsorption capacity, and the activated carbon moves downwards, adsorbing. The increase of harmful components, the adsorption and purification capacity is reduced, and the harmful components in the flue gas are gradually increased after the purification, so that the average mixing of the upper and lower sides may not meet the requirements of the flue gas emission, and if the upper concentration is lower, the flue gas can be discharged to the standard. Direct discharge, the lower than the standard flue gas is returned to the adsorption tower inlet for purification, or enter the secondary adsorption tower for purification.

It is an object of the present invention to provide a novel flue gas desulfurization and denitration apparatus in which an outlet chamber of an adsorption tower is divided into two or more layers. Adjust the residence time of activated carbon in the activated carbon bed by adjusting the discharge valve (5) at the bottom of the activated carbon bed of the adsorption tower to ensure that the pollutant content in the flue gas discharged from the upper or upper middle layer of the gas outlet is in compliance with the requirements or in compliance with regulations. Inside. That is, the content is lower than the set limit value.

According to a first embodiment of the present invention, there is provided a flue gas desulfurization and denitration apparatus comprising a primary adsorption tower (T1) and an activated carbon regeneration tower (or analytical tower) (T3), wherein the activated carbon analysis tower (T3) has an upper portion The heating zone, the middle buffer zone and the lower cooling zone are connected to the heating gas inlet pipe (L1a) and the heating gas outlet pipe (L1b) in the lower side portion and the upper side portion of the upper heating zone, respectively, in the lower cooling zone The lower side portion and the upper side portion are respectively connected to the cooling gas input pipe (L2a) and the cooling gas output pipe (L2b), and the acid gas delivery pipe (L3a) drawn from the buffer side portion in the middle of the analysis tower (T3) is connected to the system. An acid system characterized in that a heating gas branch pipe (L3a') is branched from a starting end (or a front end) of the acid gas delivery pipe (L3a), and the other end of the heating gas branch pipe (L3a') is heated with a heating gas The input pipe (L1a) is in communication with or in communication with the heating gas outlet pipe (L1b) such that the heating gas branch pipe (L3a') acts as a branch pipe branched from the heating gas input pipe (L1a) or as a slave heating gas output pipe (L1b) a branch pipe that is branched up;

The first adsorption tower (T1) comprises a main structure (1), a feed bin (2) at the top of the primary adsorption tower (T1), an inlet chamber (3), and a raw smoke leading to the inlet chamber (3). The gas conveying flue is the first flue gas pipeline (L1), the adsorption tower bottom silo discharge valve (4), the activated carbon bed bottom discharge valve (5), the perforated plate (6), and the outlet chamber.

Preferably, the outlet chamber is divided into an upper outlet chamber (a) and a lower outlet chamber (b), wherein A second flue gas duct (L2) outputting pure flue gas in the upper air outlet chamber (a) is connected to the exhaust chimney, and a third flue gas duct (L3) for outputting flue gas from the lower air outlet chamber (b) is returned The upstream of the inlet chamber (3) merges or merges with the original flue gas conveying flue, that is, the first flue gas duct (L1).

Typically, the primary adsorption column (T1) has an activated carbon bed, two activated carbon beds or a plurality of activated carbon beds (A, B, C), preferably 2-5 beds.

In general, the column height of the primary adsorption column (T1) is 10-50 m, preferably 13-45 m, preferably 15-40 m, more preferably 18-35 m.

Generally, the ratio of the height of the upper outlet chamber (a) to the lower outlet chamber (b) in the vertical direction is 0.7-1.3:1, preferably 0.8-1.2:1, preferably 0.9-1.1:1, such as 1:1.

Typically, the two or more beds of activated carbon are formed by separating the perforated plates.

According to a second embodiment of the present invention, there is provided a flue gas desulfurization and denitration apparatus comprising:

1) a primary adsorption column (T1) and a secondary adsorption column (T2) connected in series, the column heights of the adsorption columns (T1) and (T2) being independently, for example, 10-50 m, preferably 13-45 m, preferably 15 -40m, more preferably 18-35m; and

2) Activated carbon regeneration tower (or analytical tower) (T3),

The activated carbon analysis tower (T3) has an upper heating zone, a middle buffer zone and a lower cooling zone, and a heating gas inlet pipe (L1a) and a heating gas output pipe are respectively connected to the lower side portion and the upper side portion of the upper heating zone. (L1b), a cooling gas inlet pipe (L2a) and a cooling gas output pipe (L2b) are connected to the lower side portion and the upper side portion of the lower cooling zone, respectively, and the acidity is extracted from the buffer side portion in the middle of the analysis tower (T3) The gas delivery pipe (L3a) is connected to the acid production system, characterized in that a heating gas branch pipe (L3a') is branched from the start end (or front end) of the acid gas delivery pipe (L3a), and the heating gas branch pipe ( The other end of L3a') is in communication with the heating gas input pipe (L1a) or with the heating gas output pipe (L1b) such that the heating gas branch pipe (L3a') serves as a branch pipe branched from the heating gas input pipe (L1a) or As a branch pipe branched from the heating gas outlet pipe (L1b);

Wherein, the primary adsorption tower (T1) comprises a main structure (1), a feed bin (2) located at the top of the primary adsorption tower (T1), an inlet chamber (3), and an inlet to the inlet chamber (3) The flue gas conveying flue is the first flue gas pipeline (L1), the adsorption tower bottom silo discharge valve (4), the activated carbon bed bottom discharge valve (5), the perforated plate (6), and the outlet chamber.

The secondary adsorption tower (T2) comprises a main structure (1), a feed bin (2) at the top of the adsorption tower (T2), an inlet chamber (3'), and a third passage to the inlet chamber (3'). Flue gas pipeline (L3), adsorption tower bottom discharge valve (4), activated carbon bed bottom discharge valve (5), perforated plate (6), and outlet chamber (9), and

The lower outlet chamber (b) of the primary adsorption tower (T1) is connected by piping to the inlet chamber (3') of the secondary adsorption column (T2).

Preferably, the outlet chamber of the primary adsorption tower (T1) is divided into an upper outlet chamber (a) and a lower outlet chamber (b), wherein the second flue gas for outputting pure flue gas from the upper outlet chamber (a) is divided. The pipe (L2) is connected to the discharge chimney, and the third flue gas duct (L3) for outputting flue gas from the lower outlet chamber (b) is connected to the intake chamber (3') of the secondary adsorption tower (T2), And optionally, the fourth flue gas duct (L4) outputting flue gas from the outlet chamber (9) of the secondary adsorption tower (T2) merges or merges with the second flue gas duct (L2) and leads to the discharge chimney; or

The outlet chamber of the primary adsorption tower (T1) is divided into an upper outlet chamber (a), a middle outlet chamber (c) and a lower outlet chamber (b), wherein the first outlet for outputting pure flue gas from the upper outlet chamber (a) The two flue gas duct (L2) is connected to the exhaust chimney, and the third flue gas duct (L3) for outputting flue gas from the lower outlet chamber (b) is connected to the intake chamber of the secondary adsorption tower (T2) (3) '), the fifth flue gas duct (L5) for outputting flue gas from the central air outlet chamber (c) is respectively connected to the second flue gas duct (L2) or the third flue gas duct (L3) via the switching valve (10) And, optionally, the fourth flue gas duct (L4) that outputs flue gas from the outlet chamber (9) of the secondary adsorption tower (T2) merges or merges with the second flue gas duct (L2) and then leads to discharge chimney.

In the present application, preferably, the primary adsorption column (T1) can be used in parallel in two or more. The secondary adsorption column (T2) can also be used in parallel in two or more. The outlet chambers of the juxtaposed primary adsorption tower (T1) are separated into upper and lower chambers (a, b) or upper, middle and lower chambers (a, c, b), that is, divided into two levels or Three levels, and, more preferably, the tubes that exhaust the flue gases from the chambers of the same level of different adsorption towers may be combined or merged. When the first-stage adsorption tower (T1) in the form of a symmetrical double column is in the form of two or more juxtaposed adsorption towers (T1), it is juxtaposed as each of the symmetric double towers of the first-stage adsorption tower (T1). The outlet chambers are respectively separated into upper and lower chambers (a, b) or upper, middle and lower chambers (a, c, b), that is, divided into two levels or three levels, and, more preferably, The pipes that exhaust the flue gas from the chambers of the same level of different adsorption towers may be combined or merged.

Generally, the primary adsorption tower (T1) or the secondary adsorption tower (T2) each independently has one activated carbon bed, two activated carbon beds or a plurality of activated carbon beds (A, B, C), preferably 2-5 Bed. The two or more activated carbon beds are formed by separating the porous plates.

Generally, the primary adsorption column (T1) and the secondary adsorption column (T2) have the same or different structures and sizes from each other.

In general, the column heights of the primary adsorption column (T1) and the secondary adsorption column (T2) are each independently from 10 to 50 m, preferably from 13 to 45 m, preferably from 15 to 40 m, more preferably from 18 to 35 m.

Generally, generally, when the primary adsorption tower (T1) has an upper outlet chamber (a) and a lower outlet chamber (b), the heights of both the upper outlet chamber (a) and the lower outlet chamber (b) in the vertical direction are The ratio is 0.7-1.3:1, preferably 0.8-1.2:1, preferably 0.9-1.1:1, such as 1:1. When the primary adsorption tower (T1) has an upper outlet chamber (a), a central outlet chamber (c), and a lower outlet chamber (b), the upper outlet chamber (a), the central outlet chamber (c), and the lower outlet chamber ( b) The ratio of the heights of the three in the vertical direction is 0.5-1.0: 0.5-1.0: 0.8-1, preferably 0.6-0.9: 0.6-0.9: 0.8-1, preferably 0.7-0.8: 0.7-0.8: 0.8-1 .

The primary adsorption column (T1) and the secondary adsorption column (T2) have the same or different structures and sizes from each other.

In general, in the apparatus according to the first embodiment and the second embodiment, the activated carbon analysis column (T3) has an upper heating zone, a middle buffer zone, and a lower cooling zone, on the lower side and upper portion of the upper heating zone. A heating gas input pipe (L1a) and a heating gas output pipe (L1b) are respectively connected to the side portions, and a cooling gas input pipe (L2a) and a cooling gas output pipe (L2b) are respectively connected to the lower side portion and the upper side portion of the lower cooling zone. The acid gas delivery pipe (L3a) drawn from the side of the buffer zone in the middle of the analytical column (T3) is connected to the acid-making system (or acid-making zone).

Preferably, a heating gas branch pipe (L3a') is branched from the start end (or front end) of the acid gas delivery pipe (L3a), and the other end of the heating gas branch pipe (L3a') (for example, via a valve) is The heating gas input pipe (L1a) is in communication with or in communication with the heating gas output pipe (L1b) such that the heating gas branch pipe (L3a') acts as a branch pipe branched from the heating gas input pipe (L1a) or as a slave heating gas output pipe ( Branch branch on L1b).

In the present application, preferably, the primary adsorption column (T1) can be used in parallel in two or more. The secondary adsorption column (T2) can also be used in parallel in two or more. The outlet chambers of the parallel primary adsorption tower are respectively separated into upper and lower chambers (a, b) or upper, middle and lower chambers (a, c, b), that is, divided into two levels or three levels. And, more preferably, the conduits for exhausting the flue gases from the chambers of the same level of different adsorption towers may be combined or merged. When the first-stage adsorption tower (T1) in the form of a symmetrical double tower is used as two or more juxtaposed primary adsorption towers, it is juxtaposed as each of the first-stage adsorption towers. The outlet chambers of the double towers are respectively separated into upper and lower chambers (a, b) or upper, middle and lower chambers (a, c, b), that is, divided into two levels or three levels, and More preferably, the conduits for exhausting fumes from the chambers of the same level of different adsorption columns may be combined or merged.

Generally, since the flue gas is treated by the primary adsorption tower, a part of the original flue gas (for example, 20-60% of the original flue gas, preferably 30-50% of the original flue gas) reaches the discharge standard, and can be directly discharged, so The number of stages of adsorption towers is greater than the number of secondary adsorption towers. Generally, the primary adsorption column is 2-8, preferably 3-6, more preferably 4-5; the secondary adsorption column is 1-6, preferably 2-5, more preferably 3-4 One. For example, there are 4 primary adsorption towers and 2 secondary adsorption towers.

According to a third embodiment of the present invention, there is provided a flue gas desulfurization and denitration method using the desulfurization and denitration apparatus according to the first embodiment, the method comprising the steps of:

I) Desulfurization and denitration step: the original flue gas is sent to the inlet chamber (3) of the primary adsorption tower (T1) via the first flue gas pipeline (L1) and then sequentially flows through one of the primary adsorption towers (T1) or In multiple activated carbon beds, the flue gas is in cross-flow contact with the activated carbon added from the top of the primary adsorption tower (T1), wherein the flue gas contains pollutants (such as sulfur oxides, nitrogen oxides, dust, dioxins). After being removed or partially removed by the activated carbon, the flue gas is then introduced into the outlet chamber of the primary adsorption tower (T1), and the activated carbon adsorbing the pollutants is discharged from the bottom of the primary adsorption tower (T1); preferably At the same time as the above operation, the diluted ammonia gas is introduced into the flue gas input pipe (L1) of the primary adsorption tower (T1) and optionally into the primary adsorption tower (T1);

II) Activated carbon analysis step: transferring the activated carbon adsorbed by the pollutant from the bottom of the primary adsorption tower (T1) to the heating zone of an activated carbon analytical tower (T3) having an upper heating zone and a lower cooling zone, The activated carbon is analyzed and regenerated, and the analyzed and regenerated activated carbon is discharged from the bottom of the desorption column (T3) after passing through the cooling zone; wherein: nitrogen is introduced into the upper part of the analytical column (T3) during the analysis, and optional At the same time, nitrogen is introduced into the lower portion of the analytical column (T3) via the second nitrogen gas line; and the gas introduced into the analytical column (T3) is thermally desorbed from the activated carbon, including SO ₂ and NH ₃ . The material is taken out from the intermediate section between the heating zone and the cooling zone of the desorption column (T3) and sent to the acid production system via the acid gas pipeline (L3a);

Wherein, before the gaseous pollutants including SO ₂ and NH ₃ (ie, acid gases) are transported to the acid generating system via the acid gas pipeline (L3a), the heating gas branch pipe (L3a') is used from the heating gas inlet pipe (L1a). Or heating the gas from the heated gas output pipe (L1b), and flowing the heated gas through the acid gas pipe (L3a) to preheat the acid gas pipe (L3a) (for example, preheating to a temperature of 250-450 ° C, preferably 280-400 ° C, further preferably 300-380 ° C, more preferably 320-360 ° C); and, optionally, gas contaminants (ie, acid gases) including SO ₂ and NH ₃ stop flowing through the acid gas pipeline After (L3a), the heating gas is supplied from the heating gas inlet pipe (L1a) or from the heating gas output pipe (L1b) by the heating gas branch pipe (L3a'), and the heating gas is purged by the acid gas pipe (L3a) to The acid gas remaining in the acid gas pipe (L3a) is removed.

Preferably, the I) desulfurization and denitration step is carried out as follows: the raw flue gas is sent to the inlet chamber (3) of the primary adsorption tower (T1) via the first flue gas pipeline (L1), and then flows through the first stage. One or more activated carbon beds of the adsorption tower (T1), the flue gas is in cross-flow contact with the activated carbon added from the top of the primary adsorption tower (T1), wherein the flue gas contains pollutants (such as sulfur oxides, nitrogen) Oxide, dust, dioxin, etc.) are removed or partially removed by activated carbon, and then the flue gas enters the upper air outlet chamber (a) and the lower air outlet chamber (b) of the primary adsorption tower (T1), from one The flue gas discharged from the upper air outlet chamber (a) of the stage adsorption tower (T1) is sent to the discharge chimney via the second flue gas duct (L2) for discharge, from the lower air outlet chamber of the primary adsorption tower (T1) (b) The flue gas containing a small amount of pollutants discharged through the third flue gas pipeline (L3) is returned to merge with the original flue gas in the first flue gas pipeline (L1), and the activated carbon adsorbing the pollutants is from the primary adsorption tower. (T1) bottom discharge; preferably, while the above operation is performed, the diluted ammonia gas is introduced into the flue gas input pipe (L1) of the primary adsorption tower (T1) and An optionally opens into the adsorption column (T1).

Preferably, the residence time or the downward movement speed of the activated carbon in the activated carbon bed in the primary adsorption tower (T1) is adjusted by adjusting the rotation speed of the discharge valve (5) at the bottom of the activated carbon bed of the primary adsorption tower (T1), so that the first stage The pollutant content of the flue gas in the upper air outlet chamber (a) of the adsorption tower (T1) is within the scope of compliance with the requirements or compliance with regulations. That is, the content is lower than the set limit value.

It is further preferred to utilize a heated gas branch before the activation of the activated carbon analysis step or before the gaseous contaminants including SO ₂ and NH ₃ (ie, acid gases) are transported to the acid production system via the acid gas conduit (L3a) ( L3a') outputting a heating gas from the heating gas input pipe (L1a) or from the heating gas output pipe (L1b), and flowing the heating gas through the acid gas pipe (L3a) to preheat the acid gas pipe (L3a) (for example, It is heated to a temperature of from 250 to 450 ° C, preferably from 280 to 400 ° C, further preferably from 300 to 380 ° C, more preferably from 320 to 360 ° C).

More preferably, after the end of the activated carbon analysis step or after the gas contaminant (ie, acid gas) including SO ₂ and NH ₃ stops flowing through the acid gas pipe (L3a), the heated gas branch pipe (L3a') is used to heat the gas. The heating gas is output from the heating pipe (L1b) in the input pipe (L1a), and the heating gas is purged by the acid gas pipe (L3a) to remove the acid gas remaining in the acid gas pipe (L3a).

According to a fourth embodiment of the present invention, there is provided a flue gas desulfurization and denitration method using the desulfurization and denitration apparatus according to the second embodiment 2, the method comprising the steps of:

I) Desulfurization and denitration steps:

1) The raw flue gas is sent to the inlet chamber (3) of the primary adsorption tower (T1) via the first flue gas pipeline (L1), and then flows through one or more activated carbon beds of the primary adsorption tower (T1) in sequence. The flue gas is in cross-flow contact with the activated carbon added from the top of the first adsorption tower (T1), wherein the pollutants contained in the flue gas (such as sulfur oxides, nitrogen oxides, dust, dioxin, etc.) are removed by the activated carbon. Except or partial removal, after

2) The flue gas enters the outlet chamber of the first adsorption tower (T1), and the activated carbon adsorbed with the pollutants is discharged from the bottom of the first adsorption tower (T1); from the lower outlet chamber of the first adsorption tower (T1) (b The flue gas containing a small amount of pollutants discharged through the pipeline is sent to the inlet chamber (3') of the secondary adsorption tower (T2) and sequentially flows through one or more activated carbon beds of the secondary adsorption tower (2) a layer in which pollutants (such as sulfur oxides, nitrogen oxides, dust, dioxins, etc.) contained in the flue gas are further removed by the activated carbon; discharged from the outlet chamber (10) of the secondary adsorption tower (T2) The flue gas is discharged through the chimney, and the activated carbon adsorbing the pollutants is discharged from the bottom of the secondary adsorption tower (T2); preferably, the dilute ammonia gas is introduced into the first adsorption tower (T1) at the same time as the above operation. A flue gas duct (L1) is neutralized and optionally passed to a conduit for transporting flue gas to the secondary adsorption tower (T2) and optionally to a primary adsorption tower (T1) and/or a secondary adsorption tower ( Within T2);

with

II) Activated carbon analysis step: transferring activated carbon adsorbed with pollutants from the bottom of the primary adsorption tower (T1) and/or the bottom of the secondary adsorption tower (T2) to a cooling zone having an upper heating zone and a lower cooling zone In the heating zone of the activated carbon analysis tower (T3), the activated carbon is analyzed and regenerated, and the analyzed and regenerated activated carbon flows downward through the cooling zone and is discharged from the bottom of the desorption column (T3); wherein: nitrogen is introduced during the analysis process. Going to the upper part of the analytical column (T3), and optionally simultaneously passing nitrogen gas into the lower portion of the analytical column (T3) via the second nitrogen gas line; and, the nitrogen gas flowing into the analytical column (T3) is thermally desorbed from the activated carbon The gaseous contaminants including SO ₂ and NH ₃ are taken out from the intermediate section between the heating zone and the cooling zone of the desorption column (T3) and sent to the acid production system via the acid gas pipeline (L3a);

Wherein, before the gaseous pollutants including SO ₂ and NH ₃ (ie, acid gases) are transported to the acid generating system via the acid gas pipeline (L3a), the heating gas branch pipe (L3a') is used from the heating gas inlet pipe (L1a). Or heating the gas from the heated gas output pipe (L1b), and flowing the heated gas through the acid gas pipe (L3a) to preheat the acid gas pipe (L3a) (for example, preheating to a temperature of 250-450 ° C, preferably 280-400 ° C, further preferably 300-380 ° C, more preferably 320-360 ° C); and, optionally, gas contaminants (ie, acid gases) including SO ₂ and NH ₃ stop flowing through the acid gas pipeline After (L3a), the heating gas is supplied from the heating gas inlet pipe (L1a) or from the heating gas output pipe (L1b) by the heating gas branch pipe (L3a'), and the heating gas is purged by the acid gas pipe (L3a) to The acid gas remaining in the acid gas pipe (L3a) is removed. Preferably, the primary adsorption column (T1) can be used in parallel in two or more (for example 2-6, such as 3 or 4); and/or the secondary adsorption column (T2) can be used in two or more Parallel (for example, 2-4, such as 3) to use.

Preferably, the I) desulfurization and denitration steps are carried out as follows:

2) When the primary adsorption tower (T1) has an upper outlet chamber (a) and a lower outlet chamber (b), the flue gas enters the upper outlet chamber (a) of the primary adsorption tower (T1) and the lower outlet chamber (b) In the middle, the activated carbon adsorbed by the pollutant is discharged from the bottom of the first adsorption tower (T1); wherein the flue gas discharged from the upper outlet chamber (a) of the primary adsorption tower (T1) passes through the second flue gas pipeline (L2) is sent to the discharge chimney for discharge, and the flue gas containing a small amount of pollutant discharged from the lower outlet chamber (b) of the adsorption tower (T1) is sent to the secondary adsorption tower via the third flue gas duct (L3) ( In the inlet chamber (3') of T2) and sequentially flowing through one or more activated carbon beds of the secondary adsorption tower (T2), the flue gas discharged from the outlet chamber (9) of the secondary adsorption tower (T2) Conveyed to the flue gas in the second flue gas duct (L2) via the fourth flue gas duct (L4) and then discharged, or

When the primary adsorption tower (T1) has an upper outlet chamber (a), a central outlet chamber (c), and a lower outlet chamber (b), the flue gas enters the upper outlet chamber (a) of the primary adsorption tower (T1), In the central venting chamber (c) and the lower venting chamber (b), the activated carbon adsorbing the pollutants is discharged from the bottom of the primary adsorption tower (T1); wherein, from the upper venting chamber of the primary adsorption tower (T1) (a The flue gas discharged in the second flue gas duct (L2) is sent to the exhaust chimney for discharge, and the flue gas containing a small amount of pollutant discharged from the lower air outlet chamber (b) of the adsorption tower (T1) passes through the third smoke The gas pipeline (L3) is sent to the inlet chamber (3') of the secondary adsorption tower (T2) and sequentially flows through one or more activated carbon beds of the secondary adsorption tower (T2) from the secondary adsorption tower The flue gas discharged from the outlet chamber (9) of (T2) is sent to the flue gas in the second flue gas duct (L2) via the fourth flue gas duct (L4) and then discharged, from the first adsorption tower (T1) The flue gas discharged from the central air outlet chamber (c) is transported via the fifth flue gas duct (L5) and merged with the flue gas in the second flue gas duct (L2) by switching of the switching valve (10), respectively. The flue gas in the third flue gas pipeline (L3) merges, and the activated carbon adsorbing the pollutants is discharged from the bottom of the secondary adsorption tower (T2); preferably, the diluted ammonia gas is introduced into the first stage simultaneously with the above operation. a first flue gas duct (L1) of the adsorption tower (T1) and optionally a third flue gas duct (L3) for transporting flue gas to the secondary adsorption tower (T2) and optionally to a In the adsorption tower (T1) and/or the secondary adsorption tower (T2).

In the processes according to the third and fourth embodiments, it is preferred to adjust the residence time of the activated carbon in the activated carbon bed by adjusting the discharge valve (5) at the bottom of the activated carbon bed of the adsorption column to ensure the adsorption column from the first stage. The content of contaminants in the upper venting chamber (a) of (T1) or from the upper venting chamber (a) of the primary adsorption tower (T1) and the central venting chamber (c) is in compliance with regulations or compliance with regulations. Within the scope.

In the present application, "optionally" means with or without. "Optional" means yes or no.

In the prior art, when the activated carbon analysis step is started, the hot acid gas flows through the cold (for example, at ambient temperature) acid gas pipeline (L3a) at the beginning or in the early stage, causing the temperature to decrease, thereby causing condensation to form a liquid acid. The liquid acid has a strong corrosive effect on the acid gas pipeline (L3a). In order to solve this problem, a heat insulating tube and an outermost layer are generally provided with an insulating layer on the outer periphery of the acid gas pipe (L3a). The gas is heated by the heat tracing tube to ensure that the temperature of the acid gas flowing through the acid gas pipe (L3a) is higher than the dew point, that is, the acidic component is maintained in a gaseous state.

The inventors of the present application have found through research that preheating the pipe to a temperature higher than the dew point of the acid gas by preheating the gas into the acid gas pipe (L3a) before the start of the activated carbon analysis step, for example, It is heated to a temperature of from 250 to 450 ° C, preferably from 280 to 400 ° C, further preferably from 300 to 380 ° C, more preferably from 320 to 360 ° C. When the acid gas continues to flow through the acid gas pipe (L3a), the acid gas carries enough heat to maintain the temperature of the acid gas pipe (L3a) and prevent it from cooling.

Further preferably, the heating gas branch pipe (L3a') is used immediately after the gas contaminant (i.e., acid gas) including SO ₂ and NH ₃ stops flowing through the acid gas pipe (L3a) or after the end of the activated carbon analysis step. Heating gas is supplied from the heating gas input pipe (L1a) or from the heating gas output pipe (L1b), and the heating gas is purged by the acid gas pipe (L3a) to remove acid gas remaining or retained in the acid gas pipe (L3a). .

That is, the heated gas branch (L3a) is used before the activated carbon analysis step is initiated or before the gaseous contaminants (ie, acid gases) including SO ₂ and NH ₃ are transported to the acid production system via the acid gas pipeline (L3a). ') The heating gas is output from the heating gas input pipe (L1a) or from the heating gas output pipe (L1b), and the heating gas flows through the acid gas pipe (L3a) to preheat the acid gas pipe (L3a) (for example, preheating) The temperature to 250-450 ° C, preferably 280-400 ° C, further preferably 300-380 ° C, more preferably 320-360 ° C).

In addition, after the end of the activated carbon analysis step or after the gas contaminant (ie, acid gas) including SO ₂ and NH ₃ stops flowing through the acid gas pipe (L3a), the heated gas branch pipe (L3a') is used to input from the heating gas. The heating gas is output from the heating gas output pipe (L1b) in the pipe (L1a), and the heating gas is purged by the acid gas pipe (L3a) to remove the acid gas remaining in the acid gas pipe (L3a).

Activated carbon is fed from the top of the analytical column and discharged from the bottom of the column. In the heating section of the upper part of the analytical tower, the activated carbon adsorbed with the pollutants is heated to 400 ° C or higher and maintained for more than 3 hours, and the SO ₂ adsorbed by the activated carbon is released to generate "sulfur-rich gas (SRG)", and the SRG is transported to The acid production section (or acid production system) produces H ₂ SO ₄ . NO _X adsorbed activated SCR or SNCR reaction occurs, while most of dioxins are decomposed. The heat required for the analytical tower analysis is provided by a hot blast stove. After the blast furnace gas is burned in the hot blast stove, the hot flue gas (via the pipeline L1a) is sent to the shell side of the analytical tower. Most of the hot gas (L1b) after heat exchange returns to the hot air circulation fan (the other part is discharged to the atmosphere), which is fed into the hot blast stove and mixed with the newly burned high temperature hot gas. A cooling section is provided at the lower portion of the analytical tower, and air is blown through the duct (L2a) to carry the heat of the activated carbon. The cooling section is provided with a cooling fan, and the cold air is blown to cool the activated carbon, and then discharged to the atmosphere. The activated carbon from the analytical tower is sieved by activated carbon sieve to remove fine activated carbon particles and dust of less than 1.2 mm, which can improve the adsorption capacity of the activated carbon. The activated carbon sieve on the sieve is activated carbon with strong adsorption capacity, and the activated carbon is transported to the adsorption tower through the activated carbon conveyor for recycling, and the sieved material enters the ash silo. Nitrogen is required for protection during the analysis, and nitrogen is used as a carrier to carry out the harmful gases such as SO ₂ which are resolved. Nitrogen gas is introduced from the upper and lower portions of the analytical column, and is collected and discharged in the middle of the analytical column. At the same time, the SO ₂ adsorbed in the activated carbon is taken out and sent to the acid-making system to produce acid. When nitrogen gas was passed over the analytical column, it was heated to about 100 ° C with a nitrogen heater and passed to the analytical column.

Here, the first-stage adsorption tower and the second-stage adsorption tower in series refer to: the flue gas outlet of the first-stage adsorption tower Connected to the flue gas inlet of the secondary adsorption tower via a pipeline.

For the design of the flue gas (or exhaust gas) adsorption column and its adsorption process, a number of documents have been disclosed in the prior art, see, for example, US Pat. No. 5,932,179, JP 2004209332 A, and JP 3,518,090 B2 (JP 2002 095 930 A) and JP 3 351 658 B2 (J PH 083 332 347 A), JP 2005 313 035 A. This application is not described in detail.

In the present invention, for the adsorption tower (T1) or for the primary adsorption tower (T1) or the secondary adsorption tower (T2), a single tower single bed design can be used; or a single tower multiple bed design, such as an inlet chamber (3)-Desulfurized activated carbon bed (A)-Denitrated activated carbon bed (B)-Exhaust chamber, or for example, inlet chamber (3)-Desulfurized activated carbon bed (A)-Desulfurization and denitration activated carbon bed (B)-Denitration Activated carbon bed (C) - outlet chamber. A symmetric two-tower multi-bed design can also be used, as shown in Figures 7 and 8.

In the present application, the primary adsorption column (T1) serves as a primary adsorption column. The secondary adsorption tower (T2) acts as a secondary adsorption tower. The primary adsorption column (T1) as a primary adsorption column can be used in parallel in two or more. The secondary adsorption column (T2) as a secondary adsorption column can also be used in parallel in two or more. When two or more symmetric double towers are juxtaposed as a first-stage adsorption tower, the outlet chambers of each of the symmetric double towers which are juxtaposed as the primary adsorption tower are respectively separated into upper and lower chambers (a, b) or upper, lower, middle and lower chambers (a, c, b), ie divided into two levels or three levels, and, preferably, the flue gas is discharged from chambers of the same level of different adsorption towers Pipes can be merged or merged.

In general, the column heights of the primary adsorption column (T1) and the secondary adsorption column (T2) used in the present application are each independently, for example, 10 to 50 m, preferably 13 to 45 m, preferably 15 to 40 m, more preferably 18-35m. The primary adsorption column (T1) and the secondary adsorption column (T2) may adopt the same or different structures and sizes from each other, and preferably adopt the same structure and size. The tower height of the adsorption tower refers to the height from the activated carbon outlet at the bottom of the adsorption tower to the activated carbon inlet at the top of the adsorption tower, that is, the height of the main structure of the tower.

In the present invention, there is no particular requirement for the analytical column, and the prior art analytical column can be used in the present invention. Preferably, the analytical tower is a shell-type vertical analytical tower, wherein activated carbon is input from the top of the tower, flows downward through the tube, and then reaches the bottom of the tower, and the heated gas flows through the shell side to heat the gas. The body enters from one side of the column, is cooled by heat exchange with the activated carbon flowing through the tube, and is then output from the other side of the column. In the present invention, there is no particular requirement for the analytical column, and the prior art analytical column can be used in the present invention. Preferably, the analytical column is a shell-type (or shell-and-tube type) vertical analytical column in which activated carbon is input from the top of the column, flows downward through the tube section of the upper heating zone, and then reaches an upper heating zone and a lower cooling zone. A buffer space between them then flows through the tube section of the lower cooling zone and then reaches the bottom of the tower, while the heated gas (or high temperature hot air) flows through the shell side of the heating zone, heating the gas (400-450 ° C) from the analytical tower One side of the heating zone enters, is cooled by indirect heat exchange with activated carbon flowing through the heating zone, and is then output from the other side of the heating zone of the column. The cooling air enters from one side of the cooling zone of the analytical column and is indirectly heat exchanged with the resolved, regenerated activated carbon flowing through the cooling zone. After indirect heat exchange, the cooling air is warmed to 90-130 ° C (eg, about 100 ° C).

In general, the analytical column used in the present invention usually has a column height of 10 to 45 m, preferably 15 to 40 m, more preferably 20 to 35 m. The desorption column usually has a cross-sectional area of the main body of 6 to 100 m 2 , preferably 8 to 50 m 2 , more preferably 10 to 30 m 2 , further preferably 15 to 20 m 2 .

In the present invention, "the same level of chamber" refers to two or more adsorption towers, and the outlet chamber of each adsorption tower is divided into upper and lower chambers (or divided into upper, middle and lower three chambers). Chamber), the upper chambers of all the adsorption tower outlet chambers are the same level chambers, and the middle chambers of all the adsorption tower outlet chambers are also the same level chambers. Similarly, the lower chambers of all the adsorption tower outlet chambers are The same level of chambers.

In this application, "analysis" and "regeneration" are used interchangeably.

Advantages of the invention

1. Use a heated gas branch (L3a') before the activated carbon analysis step is initiated or before the gaseous contaminants (ie, acid gases) including SO ₂ and NH ₃ are transported to the acid system via the acid gas line (L3a). The heating gas is outputted from the heating gas input pipe (L1a) or from the heating gas output pipe (L1b) for preheating the acid gas pipe, and after the carbonization analysis step is finished, the heating gas is purged by the acid gas pipe ( L3a) to remove the acid gas remaining in the acid gas pipe (L3a). It can significantly prevent the corrosive action of acid gas on the acid gas delivery pipeline.

2. The process and device of the present application utilizes the adsorption capacity of the activated carbon in the upper part of the adsorption tower to have a large purification capacity, a good purification effect, and a low concentration of harmful components in the flue gas after purification, and the adsorption tower outlet chamber is divided into a whole by the past. Two or more layers above and below, so that the flue gas purified by the adsorption tower is segmented into different flue according to the degree of purification, and the concentration of harmful components in the flue gas reaches the standard flue. Directly discharged into the chimney, the flue gas that can not reach the standard discharge enters the next-stage adsorption tower or is returned to the inlet of the adsorption tower for further purification, so that the amount of flue gas entering the next stage will be reduced by 30% to 50%, which can be reduced. The ability of the pressure blower and secondary adsorption tower to reduce investment and operating costs.

DRAWINGS

1 is a schematic diagram of a prior art desulfurization and denitration apparatus including an activated carbon adsorption tower and an activated carbon regeneration tower.

2 is a schematic view showing the process flow of a prior art flue gas desulfurization and unsalable device (Sumitomo Corporation of Japan).

3 is a schematic view showing the process flow of another flue gas desulfurization and unsalable device (Shanghai Ke Sulphur Co., Ltd.) of the prior art.

Fig. 4 is a schematic view showing the process flow of the flue gas desulfurization and denitration apparatus of the first embodiment of the present invention.

Fig. 5 is a schematic view showing the process flow of a flue gas desulfurization and denitration apparatus according to a second embodiment of the present invention.

Fig. 6 is a schematic view showing the process flow of another flue gas desulfurization and denitration apparatus according to a second embodiment of the present invention.

Fig. 7 is a schematic view of an adsorption tower designed according to the symmetrical two-bed multi-bed layer of the present invention (with no interstitial spaces between the beds).

Fig. 8 is a schematic view of an adsorption tower designed according to the symmetrical two-bed multi-bed layer of the present invention (with a gap space between each bed layer).

Reference numeral

T1: adsorption tower or primary adsorption tower; T2: secondary adsorption tower; 1: main body of adsorption tower; 2: activated carbon feed silo; 3 or 3': adsorption tower inlet chamber, 4: adsorption tower bottom silo unloading Feed valve (or rotary valve); 5: roller feeder (or rotary valve) at the bottom of the activated carbon bed; 6: porous separator; 7: booster fan; 8, 8a, 8b: activated carbon conveyor; The outlet chamber of the secondary adsorption tower; 10: switching valve.

A, B, C, D, E: activated carbon bed; a: upper venting chamber, c: central venting chamber, b: lower venting chamber; L1: original flue gas conveying flue or first flue gas duct; L2: Two flue gas pipelines (or Net flue gas conveying pipeline); L3: third flue gas pipeline; L4: fourth flue gas pipeline; L5: fifth flue gas pipeline.

T3: desorption tower (or regeneration tower); S1: activated carbon shaker; N2: nitrogen delivery pipe.

L1a: heating gas input pipe; L1b: heating gas output pipe (); L2a: cooling gas input pipe; L2b: cooling gas output pipe; L3a: acid gas delivery pipe; L3a': heating gas branch pipe.

h: height of the adsorption section.

detailed description

In all embodiments, the original flue gas SO ₂ and NOx contents were 300mg / Nm ^³ -4000mg / Nm ³ and ^{^{200mg / Nm 3 -500mg / Nm 3}} .

Specific embodiments of the present application are described below:

Preferably, the outlet chamber is partitioned into an upper outlet chamber (a) and a lower outlet chamber (b), wherein the second flue gas duct (L2) for outputting pure flue gas from the upper outlet chamber (a) is connected to the discharge a chimney, and a third flue gas duct (L3) for outputting flue gas from the lower air outlet chamber (b) is returned to the intake chamber (3) The swim merges or merges with the original flue gas conveying flue, the first flue gas duct (L1).

2) Activated carbon regeneration tower (or analytical tower) (T3),

The secondary adsorption tower (T2) comprises a main structure (1), a feed bin (2) at the top of the adsorption tower (T2), an inlet chamber (3'), and a third passage to the inlet chamber (3'). Flue gas pipeline (L3), adsorption tower bottom discharge valve (4) a bottom discharge valve (5), a perforated plate (6), and an outlet chamber (9) of the activated carbon bed, and

Generally, when the primary adsorption tower (T1) has an upper outlet chamber (a) and a lower outlet chamber (b), the ratio of the heights of the upper outlet chamber (a) and the lower outlet chamber (b) in the vertical direction is 0.7-1.3:1, preferably 0.8-1.2:1, preferably 0.9-1.1:1, such as 1:1. When the primary adsorption tower (T1) has an upper outlet chamber (a), a central outlet chamber (c), and a lower outlet chamber (b), the upper outlet chamber (a), the central outlet chamber (c), and the lower outlet chamber ( b) The ratio of the heights of the three in the vertical direction is 0.5-1.0: 0.5-1.0: 0.8-1, preferably 0.6-0.9: 0.6-0.9: 0.8-1, preferably 0.7-0.8: 0.7-0.8: 0.8-1 .

Preferably, a heating gas branch pipe (L3a') is branched from the start end (or front end) of the acid gas delivery pipe (L3a), and the other end of the heating gas branch pipe (L3a') (for example, via a valve) is The heating gas input pipe (L1a) is in communication with and/or in communication with the heating gas output pipe (L1b) such that the heating gas branch pipe (L3a') acts as a branch pipe branched from the heating gas input pipe (L1a) or as a heating gas output a branch pipe that is branched on the tube (L1b).

In the present application, preferably, the primary adsorption column (T1) can be used in parallel in two or more. The secondary adsorption column (T2) can also be used in parallel in two or more. The outlet chambers of the juxtaposed primary adsorption tower (T1) are separated into upper and lower chambers (a, b) or upper, middle and lower chambers (a, c, b), that is, divided into two levels or Three levels, and, more preferably, the tubes that exhaust the flue gases from the chambers of the same level of different adsorption towers may be combined or merged. When the first-stage adsorption tower (T1) in the form of a symmetrical double column is in the form of two or more juxtaposed adsorption towers (T1), it is juxtaposed as each of the symmetric double towers of the first-stage adsorption tower (T1). The outlet chambers are respectively separated into upper and lower chambers (a, b) or upper, middle and lower chambers (a, c, b), that is, divided into two levels or three levels, and, more preferably, From different adsorption towers The pipes for discharging the flue gas in the chambers of the same level may be combined or merged.

II) Activated carbon analysis step: transferring the activated carbon adsorbed by the pollutant from the bottom of the primary adsorption tower (T1) to the heating zone of an activated carbon analytical tower (T3) having an upper heating zone and a lower cooling zone, The activated carbon is analyzed and regenerated, and the analyzed and regenerated activated carbon is discharged from the bottom of the desorption column (T3) after passing through the cooling zone; wherein: nitrogen is introduced into the upper part of the analytical column (T3) during the analysis, and optional At the same time, nitrogen is introduced into the lower portion of the analytical column (T3) via the second nitrogen gas line; and the gas contaminants including SO2 and NH3 which are thermally desorbed from the activated carbon by the nitrogen gas flowing into the analytical column (T3) are The intermediate section between the heating zone and the cooling zone of the desorption column (T3) is taken out and sent to the acid production system via the acid gas pipeline (L3a);

Preferably, the I) desulfurization and denitration step is carried out as follows: the raw flue gas is sent to the inlet chamber (3) of the primary adsorption tower (T1) via the first flue gas pipeline (L1), and then flows through the first stage. Adsorption tower (T1) One or more activated carbon beds, the flue gas is in cross-flow contact with the activated carbon added from the top of the primary adsorption tower (T1), wherein the flue gas contains pollutants (such as sulfur oxides, nitrogen oxides, dust, Dioxins, etc.) are removed or partially removed by activated carbon, and then the flue gas enters the upper outlet chamber (a) and the lower outlet chamber (b) of the primary adsorption tower (T1), from the primary adsorption tower (T1). The flue gas discharged from the upper air outlet chamber (a) is sent to the discharge chimney via the second flue gas duct (L2) for discharge, and the small amount discharged from the lower air outlet chamber (b) of the primary adsorption tower (T1) The flue gas of the pollutant is transported back through the third flue gas pipeline (L3) to merge with the original flue gas in the first flue gas duct (L1), and the activated carbon adsorbing the pollutant is discharged from the bottom of the first adsorption tower (T1). Preferably, at the same time as the above operation, the diluted ammonia gas is introduced into the flue gas input line (L1) of the primary adsorption column (T1) and optionally into the primary adsorption column (T1).

Preferably, the residence time or the downward movement speed of the activated carbon in the activated carbon bed in the primary adsorption tower (T1) is adjusted by adjusting the rotation speed of the discharge valve (5) at the bottom of the first adsorption tower (T1), so that the first adsorption The pollutant content of the flue gas in the upper air outlet chamber (a) of the tower (T1) is within the scope of compliance with the requirements or compliance with regulations. That is, the content is lower than the set limit value.

I) Desulfurization and denitration steps:

1) The raw flue gas is sent to the inlet chamber (3) of the primary adsorption tower (T1) via the first flue gas pipeline (L1), and then flows through one or more activated carbon beds of the primary adsorption tower (T1) in sequence. , smoke and suck from the first The activated carbon added to the top of the tower (T1) is subjected to cross-flow contact, in which the pollutants (such as sulfur oxides, nitrogen oxides, dust, dioxin, etc.) contained in the flue gas are removed or partially removed by the activated carbon, after which ,

with

Preferably, the primary adsorption column (T1) can be used in parallel in two or more (for example 2-6, such as 3 or 4); and/or the secondary adsorption column (T2) can be used in two or more Parallel (for example, 2-4, such as 3) to use.

When the primary adsorption tower (T1) has an upper outlet chamber (a), a central outlet chamber (c), and a lower outlet chamber (b), the flue gas enters the upper outlet chamber (a) of the primary adsorption tower (T1), In the central venting chamber (c) and the lower venting chamber (b), the activated carbon adsorbing the pollutants is discharged from the bottom of the primary adsorption tower (T1); wherein, from the upper venting chamber of the primary adsorption tower (T1) (a The flue gas discharged in the second flue gas duct (L2) is sent to the exhaust chimney for discharge, and the flue gas containing a small amount of pollutant discharged from the lower air outlet chamber (b) of the adsorption tower (T1) passes through the third smoke The gas pipeline (L3) is sent to the inlet chamber (3') of the secondary adsorption tower (T2) and sequentially flows through one or more activated carbon beds of the secondary adsorption tower (T2) from the secondary adsorption tower (T2) The flue gas discharged from the outlet chamber (9) is sent to the flue gas in the second flue gas duct (L2) via the fourth flue gas duct (L4) and then discharged, from the first adsorption tower (T1) The flue gas discharged from the central air outlet chamber (c) is transported via the fifth flue gas duct (L5) and merged with the flue gas in the second flue gas duct (L2) or the third by switching of the switching valve (10), respectively. Flue gas pipeline (L3) The flue gas merges, and the activated carbon adsorbing the pollutants is discharged from the bottom of the secondary adsorption tower (T2); preferably, the first smoke of the diluted ammonia gas is introduced into the primary adsorption tower (T1) at the same time as the above operation. Gas pipeline (L1) and optionally pass Into the third flue gas line (L3) which transports flue gas for the secondary adsorption column (T2) and optionally into the primary adsorption column (T1) and/or the secondary adsorption column (T2).

In the processes according to the third and fourth embodiments, it is preferred to adjust the residence time of the activated carbon in the activated carbon bed by adjusting the discharge valve (5) at the bottom of the activated carbon bed of the adsorption column to ensure the adsorption tower (T1) In the upper venting chamber (a) or in the flue gas discharged from the upper venting chamber (a) and the central venting chamber (c) of the primary adsorption tower (T1), the content of pollutants in the flue gas meets the requirements or meets the regulations. .

Preferably, the residence time or the downward movement speed of the activated carbon in the activated carbon bed in the primary adsorption tower (T1) is adjusted by adjusting the rotation speed or opening degree of the discharge valve (5) at the bottom of the activated carbon bed of the primary adsorption tower (T1). , such that the pollutant content of the flue gas in the upper air outlet chamber (a) of the primary adsorption tower (T1) and optionally the pollutant content of the flue gas in the central air outlet chamber (c) are in compliance with requirements or comply with regulations Within the scope. That is, the content is lower than the set limit value.

In the present application, the residence time of the activated carbon in the activated carbon bed is adjusted by adjusting the bottom discharge valve (5) of the primary adsorption tower (T1) bed to ensure the upper outlet chamber from the primary adsorption tower (T1) (a The content of pollutants in the flue gas discharged from the upper air outlet chamber (a) and the central air outlet chamber (c) of the primary adsorption tower (T1) is within the scope of compliance with the requirements or compliance with regulations.

In addition, in the prior art, when the activated carbon analysis step is started, the hot acid gas is opened. When the cold or low (for example, at ambient temperature) acid gas pipeline (L3a) flows, the temperature is lowered, condensation occurs, and a liquid acid is formed. The liquid acid has a strong corrosive effect on the acid gas pipeline (L3a). In order to solve this problem, a sleeve and an outermost layer are generally provided with an insulating layer on the outer periphery of the acid gas pipe (L3a). By passing a high-temperature heating gas into the casing, it is ensured that the temperature of the acid gas flowing through the acid gas pipe (L3a) is higher than the dew point, that is, the acidic component is maintained in a gaseous state.

Here, the first-stage adsorption tower and the second-stage adsorption tower in series mean that the flue gas outlet of the primary adsorption tower is connected to the flue gas inlet of the secondary adsorption tower via a pipeline.

In the present invention, for the adsorption tower (T1) or for the primary adsorption tower (T1) or the secondary adsorption tower (T2), a single tower single bed design can be used; or a single tower multiple bed design, such as an inlet chamber (3)-Desulfurization activated carbon bed (A)-Denitration activated carbon bed (B)-Exhaust chamber or, for example, inlet chamber (3)-Desulfurization activated carbon bed (A)-Desulfurization and denitration activated carbon bed (B)-Denitration activated carbon Bed (C) - venting chamber. A symmetrical twin tower design can also be used, as shown in Figure 7 or 8.

In the present invention, there is no particular requirement for the analytical column, and the prior art analytical column can be used in the present invention. Preferably, the analytical column is a shell-type vertical analytical column in which activated carbon is input from the top of the column, flows downward through the tube, and then reaches the bottom of the column, while the heated gas flows through the shell side, and the heated gas enters from one side of the column. It is cooled by heat exchange with activated carbon flowing through the tube and then output from the other side of the column. In the present invention, there is no particular requirement for the analytical column, and the prior art analytical column can be used in the present invention. Preferably, the analytical column is a shell-type (or shell-and-tube type) vertical analytical column in which activated carbon is input from the top of the column, flows downward through the tube section of the upper heating zone, and then reaches an upper heating zone and a lower cooling zone. A buffer space between them then flows through the tube section of the lower cooling zone and then reaches the bottom of the tower, while the heated gas (or high temperature hot air) flows through the shell side of the heating zone, heating the gas (400-450 ° C) from the analytical tower One side of the heating zone enters, is cooled by indirect heat exchange with activated carbon flowing through the heating zone, and is then output from the other side of the heating zone of the column. Cooling wind From the side of the cooling zone of the analytical column, indirect heat exchange with the resolved, regenerated activated carbon flowing through the cooling zone tube. After indirect heat exchange, the cooling air is warmed to 90-130 ° C (eg, about 100 ° C).

For the design of activated carbon analytical towers and activated carbon regeneration methods, many documents have been disclosed in the prior art. JP3217627B2 (JPH08155299A) discloses an analytical tower (ie, a desorption tower) which uses a double sealing valve and is sealed by an inert gas. Screening, water cooling (see Figure 3 in this patent). JP 3485453 B2 (JPH 11104457 A) discloses a regeneration column (see Figs. 23 and 24) which can be used in a preheating section, a double sealing valve, an inert gas, air cooling or water cooling. JPS59142824A discloses a gas from a cooling section for preheating activated carbon. Chinese Patent Application No. 201210050541.6 (Shanghai Keshi Company) discloses a scheme for energy reuse of a regeneration tower in which a dryer 2 is used. JPS 4918355 B discloses the use of blast furnace gas to regenerate activated carbon. JPH08323144A discloses a regeneration tower employing fuel (heavy or light oil) using an air heating furnace (see Figure 2 of the patent, 11-hot blast stove, 12-fuel supply). The Chinese utility model 201320075942.7 relates to a heating device and an exhaust gas treatment device (combustion coal, air heating) provided with the heating device, see Fig. 2 in the utility model patent.

The analytical tower of the present invention is air cooled.

For the case where the analytical tower resolution capacity is 10 tons of activated carbon per hour, the conventional process maintains the temperature in the analytical column at 420 ° C. The required coke oven gas is about 400 Nm ³ /h, the combustion air is about 2200 Nm ³ /h, and the exhaust heat is about 2500 Nm ³ /h; required cooling air of 30000 Nm ³ /h, and the activated carbon temperature after cooling is 140 °C.

Embodiment 1

The apparatus and flow shown in Figure 4 are employed.

Embodiment 2

The apparatus and flow shown in Fig. 4 were employed, but the adsorption tower shown in Fig. 4 was replaced with the adsorption tower apparatus shown in Fig. 7.

Embodiment 3

The apparatus and flow shown in Figure 5 are employed.

Embodiment 4

The apparatus and flow shown in Fig. 5 were employed, but the adsorption tower apparatus shown in Fig. 7 was used instead of the secondary adsorption tower shown in Fig. 5.

Embodiment 5 (preferred)

The apparatus and flow shown in Figure 6 are employed.

Embodiment 6 (preferred)

The apparatus and flow shown in Fig. 6 were employed, but the adsorption tower apparatus shown in Fig. 7 was used instead of the secondary adsorption tower shown in Fig. 5.

Embodiment 7 (most preferred)

The apparatus and flow shown in Fig. 6 were employed, but the adsorption tower apparatus shown in Fig. 7 was used instead of the secondary adsorption tower shown in Fig. 5. And the first-stage adsorption tower has three juxtaposed arrangement, and the flue gas output pipelines of the same level of the flue gas chamber of the first-stage adsorption tower merge, and then the flue gas is divided into two inlet chambers which respectively pass into two juxtaposed secondary adsorption towers. . From the outlet chamber of the secondary adsorption tower (T2), the desulfurization rate of 99.2% and the denitration rate of 92% were measured.

Claims

A flue gas desulfurization and denitration device comprises a first adsorption tower (T1) and an activated carbon regeneration tower (or analytical tower) (T3), wherein the activated carbon analysis tower (T3) has an upper heating zone, a middle buffer zone and a lower zone In the cooling zone, a heating gas inlet pipe (L1a) and a heating gas outlet pipe (L1b) are respectively connected to the lower side portion and the upper side portion of the upper heating zone, and cooling is respectively connected to the lower side portion and the upper side portion of the lower cooling zone. The gas input pipe (L2a) and the cooling gas output pipe (L2b) are connected to the acid generating system (L3a) from the side of the buffer zone in the middle of the analytical tower (T3), which is characterized in that it is transported from the acid gas. A heating gas branch pipe (L3a') is branched from the start end (or front end) of the pipe (L3a), and the other end of the heating gas branch pipe (L3a') is connected to the heating gas input pipe (L1a) or is heated to be outputted. The tube (L1b) is connected such that the heating gas branch pipe (L3a') acts as a branch pipe branched from the heating gas input pipe (L1a) or as a branch pipe branched from the heating gas output pipe (L1b);

The first adsorption tower (T1) comprises a main structure (1), a feed bin (2) at the top of the primary adsorption tower (T1), an inlet chamber (3), and a raw smoke leading to the inlet chamber (3). The gas conveying flue is the first flue gas pipeline (L1), the adsorption tower bottom silo discharge valve (4), the activated carbon bed bottom discharge valve (5), the perforated plate (6), and the outlet chamber.
The apparatus according to claim 1, wherein the air outlet chamber is partitioned into an upper air outlet chamber (a) and a lower air outlet chamber (b), wherein the second smoke for outputting pure smoke from the upper air outlet chamber (a) is The gas pipe (L2) is connected to the discharge chimney, and the third flue gas duct (L3) for outputting flue gas from the lower outlet chamber (b) is returned to the upstream of the intake chamber (3) and the original flue gas conveying flue That is, the first flue gas pipeline (L1) merges or merges.
The apparatus according to claim 1 or 2, wherein the primary adsorption column (T1) has an activated carbon bed, two activated carbon beds or a plurality of activated carbon beds (A, B, C), preferably 2 to 5 beds. a layer; the two or more activated carbon beds are formed by separating the porous plates.
A flue gas desulfurization and denitration device, which comprises:

1) a primary adsorption tower (T1) and a secondary adsorption tower (T2) connected in series, and

2) Activated carbon regeneration tower (or analytical tower) (T3),

The activated carbon analysis tower (T3) has an upper heating zone, a middle buffer zone and a lower cooling zone, and a heating gas inlet pipe (L1a) and a heating gas output pipe are respectively connected to the lower side portion and the upper side portion of the upper heating zone. (L1b), a cooling gas inlet pipe (L2a) and a cooling gas output pipe (L2b) are connected to the lower side portion and the upper side portion of the lower cooling zone, respectively, and the acidity is extracted from the buffer side portion in the middle of the analysis tower (T3) The gas delivery conduit (L3a) is connected to the acid production system and is characterized by: transport from acid gas A heating gas branch pipe (L3a') is branched at the start end (or front end) of the pipe (L3a), and the other end of the heating gas branch pipe (L3a') is connected to the heating gas input pipe (L1a) or heated gas The output pipe (L1b) is connected such that the heating gas branch pipe (L3a') acts as a branch pipe branched from the heating gas input pipe (L1a) or as a branch pipe branched from the heating gas output pipe (L1b);

Wherein, the primary adsorption tower (T1) comprises a main structure (1), a feed bin (2) located at the top of the primary adsorption tower (T1), an inlet chamber (3), and an inlet to the inlet chamber (3) The flue gas conveying flue is the first flue gas pipeline (L1), the adsorption tower bottom silo discharge valve (4), the activated carbon bed bottom discharge valve (5), the perforated plate (6), and the outlet chamber.

The secondary adsorption tower (T2) comprises a main structure (1), a feed bin (2) at the top of the adsorption tower (T2), an inlet chamber (3'), and a third passage to the inlet chamber (3'). Flue gas pipeline (L3), adsorption tower bottom discharge valve (4), activated carbon bed bottom discharge valve (5), perforated plate (6), and outlet chamber (9), and

The lower outlet chamber (b) of the primary adsorption tower (T1) is connected by piping to the inlet chamber (3') of the secondary adsorption column (T2).
The apparatus according to claim 4, characterized in that the outlet chamber of the primary adsorption tower (T1) is partitioned into an upper outlet chamber (a) and a lower outlet chamber (b) for use in the outlet chamber (a) from the upper portion A second flue gas duct (L2) for outputting pure flue gas is connected to the exhaust stack, and a third flue gas duct (L3) for outputting flue gas from the lower outlet chamber (b) is connected to the secondary adsorption tower (T2) An inlet chamber (3'), and optionally a fourth flue gas duct (L4) and a second flue gas duct (L2) for outputting flue gas from an outlet chamber (9) of the secondary adsorption tower (T2) Merging or converging to the exhaust chimney; or

The outlet chamber of the primary adsorption tower (T1) is divided into an upper outlet chamber (a), a middle outlet chamber (c) and a lower outlet chamber (b), wherein the first outlet for outputting pure flue gas from the upper outlet chamber (a) The two flue gas duct (L2) is connected to the exhaust chimney, and the third flue gas duct (L3) for outputting flue gas from the lower outlet chamber (b) is connected to the intake chamber of the secondary adsorption tower (T2) (3) '), the fifth flue gas duct (L5) for outputting flue gas from the central air outlet chamber (c) is respectively connected to the second flue gas duct (L2) or the third flue gas duct (L3) via the switching valve (10) And, optionally, the fourth flue gas duct (L4) that outputs flue gas from the outlet chamber (9) of the secondary adsorption tower (T2) merges or merges with the second flue gas duct (L2) and then leads to discharge chimney.
The apparatus according to claim 4 or 5, wherein the primary adsorption tower (T1) or the secondary adsorption tower (T2) each independently has one activated carbon bed, two activated carbon beds or a plurality of activated carbon beds (A, B, C), preferably 2-5 beds; the two or more activated carbon beds are formed by separating the porous plates;

and / or

The primary adsorption column (T1) and the secondary adsorption column (T2) have the same or different structures and sizes from each other.
Apparatus according to any one of claims 1 to 6, wherein the primary adsorption column (T1) can be used in two or more juxtaposition and/or the secondary adsorption column (T2) can also be used in two or more Preferably, the outlet chambers of the parallel primary adsorption tower are respectively separated into upper and lower chambers (a, b) or upper, middle and lower chambers (a, c, b), ie, divided into Two or three levels, and, more preferably, pipes that discharge flue gas from chambers of the same level of different adsorption columns may be combined or merged;

Preferably, when the first-stage adsorption tower (T1) in the form of a symmetrical double column is used as two or more juxtaposed first-stage adsorption towers, the venting chambers of each of the symmetric double towers of the first-stage adsorption tower are juxtaposed. Separated into upper and lower chambers (a, b) or upper, middle and lower chambers (a, c, b), that is, divided into two levels or three levels, and, more preferably, from The pipes for discharging flue gas in the chambers of the same level of different adsorption towers may be combined or merged.
A flue gas desulfurization and denitration method using the desulfurization and denitration apparatus according to any one of claims 1 to 3, wherein the method comprises the following steps:

I) Desulfurization and denitration step: the original flue gas is sent to the inlet chamber (3) of the primary adsorption tower (T1) via the first flue gas pipeline (L1) and then sequentially flows through one of the primary adsorption towers (T1) or In multiple activated carbon beds, the flue gas is in cross-flow contact with the activated carbon added from the top of the primary adsorption tower (T1), wherein the flue gas contains pollutants (such as sulfur oxides, nitrogen oxides, dust, dioxins). After being removed or partially removed by the activated carbon, the flue gas is then introduced into the outlet chamber of the primary adsorption tower (T1), and the activated carbon adsorbing the pollutants is discharged from the bottom of the primary adsorption tower (T1); preferably At the same time as the above operation, the diluted ammonia gas is introduced into the flue gas input pipe (L1) of the primary adsorption tower (T1) and optionally into the primary adsorption tower (T1);

II) Activated carbon analysis step: transferring the activated carbon adsorbed by the pollutant from the bottom of the primary adsorption tower (T1) to the heating zone of an activated carbon analytical tower (T3) having an upper heating zone and a lower cooling zone, The activated carbon is analyzed and regenerated, and the analyzed and regenerated activated carbon is discharged from the bottom of the desorption column (T3) after passing through the cooling zone; wherein: nitrogen is introduced into the upper part of the analytical column (T3) during the analysis, and optional At the same time, nitrogen is introduced into the lower portion of the analytical column (T3) via the second nitrogen gas line; and the gas introduced into the analytical column (T3) is thermally desorbed from the activated carbon, including SO 2 and NH 3 . The material is taken out from the intermediate section between the heating zone and the cooling zone of the desorption column (T3) and sent to the acid production system via the acid gas pipeline (L3a);

It is characterized in that a heating gas branch pipe (L3a') is used from the heating gas inlet pipe before the gas pollutants including SO 2 and NH 3 (ie, acid gas) are sent to the acid production system via the acid gas pipe (L3a). (L1a) or the heating gas is outputted from the heating gas outlet pipe (L1b), and the heating gas flows through the acid gas pipe (L3a) to preheat the acid gas pipe (L3a) (for example, preheating to a temperature of 250-450 ° C Preferably, 280-400 ° C, further preferably 300-380 ° C, more preferably 320-360 ° C); and, optionally, gas contaminants (ie, acid gases) including SO 2 and NH 3 stop flowing After the acid gas pipe (L3a), the heating gas is supplied from the heating gas inlet pipe (L1a) or from the heating gas outlet pipe (L1b) by the heating gas pipe (L3a'), and the heating gas is purged by the acid gas pipe (L3a) ) to remove the acid gas remaining in the acid gas pipe (L3a).
The method according to claim 8, wherein the I) desulfurization and denitration steps are carried out as follows: the raw flue gas is sent to the inlet chamber (3) of the primary adsorption tower (T1) via the first flue gas duct (L1), followed by Flowing through one or more activated carbon beds of the primary adsorption tower (T1), the flue gas is in cross-flow contact with the activated carbon added from the top of the primary adsorption tower (T1), wherein the pollutants contained in the flue gas (such as sulfur Oxide, nitrogen oxides, dust, dioxins, etc.) are removed or partially removed by activated carbon, after which the flue gas enters the upper outlet chamber (a) and the lower outlet chamber (b) of the primary adsorption tower (T1) The flue gas discharged from the upper air outlet chamber (a) of the primary adsorption tower (T1) is sent to the discharge chimney via the second flue gas duct (L2) for discharge, and is discharged from the lower portion of the primary adsorption tower (T1). The flue gas containing a small amount of pollutants discharged from the chamber (b) is returned to the original flue gas in the first flue gas duct (L1) via the third flue gas duct (L3), and the activated carbon adsorbing the pollutants is The bottom of the primary adsorption tower (T1) is discharged; preferably, the diluted ammonia gas is introduced into the primary adsorption tower (T1) at the same time as the above operation. Pipe (L1) and optionally in an adsorption column into the (T1) inside.
A flue gas desulfurization and denitration method using the desulfurization and denitration apparatus according to any one of claims 4 to 7, the method comprising the steps of:

I) Desulfurization and denitration steps:

1) The raw flue gas is sent to the inlet chamber (3) of the primary adsorption tower (T1) via the first flue gas pipeline (L1), and then flows through one or more activated carbon beds of the primary adsorption tower (T1) in sequence. The flue gas is in cross-flow contact with the activated carbon added from the top of the first adsorption tower (T1), wherein the pollutants contained in the flue gas (such as sulfur oxides, nitrogen oxides, dust, dioxin, etc.) are removed by the activated carbon. Except or partial removal, after

2) The flue gas enters the outlet chamber of the first adsorption tower (T1), and the activated carbon adsorbed with the pollutants is discharged from the bottom of the first adsorption tower (T1); from the lower outlet chamber of the first adsorption tower (T1) (b Discharged The flue gas containing a small amount of pollutants is sent to the inlet chamber (3') of the secondary adsorption tower (T2) via a pipeline and sequentially flows through one or more activated carbon beds of the secondary adsorption tower (2), wherein the smoke The pollutants contained in the gas (such as sulfur oxides, nitrogen oxides, dust, dioxins, etc.) are further removed by the activated carbon; the flue gas discharged from the outlet chamber (10) of the secondary adsorption tower (T2) passes through the chimney The activated carbon that is discharged and adsorbed with pollutants is discharged from the bottom of the secondary adsorption tower (T2); preferably, the diluted ammonia gas is introduced into the first flue gas pipeline of the primary adsorption tower (T1) at the same time as the above operation. (L1) neutralization optionally in the conduit for the delivery of flue gas to the secondary adsorption column (T2) and optionally to the primary adsorption column (T1) and/or the secondary adsorption column (T2);

with

II) Activated carbon analysis step: transferring activated carbon adsorbed with pollutants from the bottom of the primary adsorption tower (T1) and/or the bottom of the secondary adsorption tower (T2) to a cooling zone having an upper heating zone and a lower cooling zone In the heating zone of the activated carbon analysis tower (T3), the activated carbon is analyzed and regenerated, and the analyzed and regenerated activated carbon flows downward through the cooling zone and is discharged from the bottom of the desorption column (T3); wherein: nitrogen is introduced during the analysis process. Going to the upper part of the analytical column (T3), and optionally simultaneously passing nitrogen gas into the lower portion of the analytical column (T3) via the second nitrogen gas line; and, the nitrogen gas flowing into the analytical column (T3) is thermally desorbed from the activated carbon The gaseous contaminants including SO 2 and NH 3 are taken out from the intermediate section between the heating zone and the cooling zone of the desorption column (T3) and sent to the acid production system via the acid gas pipeline (L3a);

It is characterized in that a heating gas branch pipe (L3a') is used from the heating gas inlet pipe before the gas pollutants including SO 2 and NH 3 (ie, acid gas) are sent to the acid production system via the acid gas pipe (L3a). (L1a) or the heating gas is outputted from the heating gas outlet pipe (L1b), and the heating gas flows through the acid gas pipe (L3a) to preheat the acid gas pipe (L3a) (for example, preheating to a temperature of 250-450 ° C Preferably, 280-400 ° C, further preferably 300-380 ° C, more preferably 320-360 ° C); and, optionally, gas contaminants (ie, acid gases) including SO 2 and NH 3 stop flowing After the acid gas pipe (L3a), the heating gas is supplied from the heating gas inlet pipe (L1a) or from the heating gas outlet pipe (L1b) by the heating gas pipe (L3a'), and the heating gas is purged by the acid gas pipe (L3a) ) to remove the acid gas remaining in the acid gas pipe (L3a); preferably, the primary adsorption column (T1) can be used in parallel in two or more; and/or the secondary adsorption column (T2) can be used in two One or more are used side by side.
The method of claim 10 wherein the I) desulfurization and denitration steps are carried out as follows:

1) The raw flue gas is sent to the inlet chamber (3) of the primary adsorption tower (T1) via the first flue gas pipeline (L1) Then, one or more activated carbon beds of the first adsorption tower (T1) are sequentially flowed, and the flue gas is in cross-flow contact with the activated carbon added from the top of the primary adsorption tower (T1), wherein the pollutants contained in the flue gas ( Such as sulfur oxides, nitrogen oxides, dust, dioxins, etc.) are removed or partially removed by activated carbon, after

2) When the primary adsorption tower (T1) has an upper outlet chamber (a) and a lower outlet chamber (b), the flue gas enters the upper outlet chamber (a) of the primary adsorption tower (T1) and the lower outlet chamber (b) In the middle, the activated carbon adsorbed by the pollutant is discharged from the bottom of the first adsorption tower (T1); wherein the flue gas discharged from the upper outlet chamber (a) of the primary adsorption tower (T1) passes through the second flue gas pipeline (L2) is sent to the discharge chimney for discharge, and the flue gas containing a small amount of pollutant discharged from the lower outlet chamber (b) of the adsorption tower (T1) is sent to the secondary adsorption tower via the third flue gas duct (L3) ( In the inlet chamber (3') of T2) and sequentially flowing through one or more activated carbon beds of the secondary adsorption tower (T2), the flue gas discharged from the outlet chamber (9) of the secondary adsorption tower (T2) Conveyed to the flue gas in the second flue gas duct (L2) via the fourth flue gas duct (L4) and then discharged, or

When the primary adsorption tower (T1) has an upper outlet chamber (a), a central outlet chamber (c), and a lower outlet chamber (b), the flue gas enters the upper outlet chamber (a) of the primary adsorption tower (T1), In the central venting chamber (c) and the lower venting chamber (b), the activated carbon adsorbing the pollutants is discharged from the bottom of the primary adsorption tower (T1); wherein, from the upper venting chamber of the primary adsorption tower (T1) (a The flue gas discharged in the second flue gas duct (L2) is sent to the exhaust chimney for discharge, and the flue gas containing a small amount of pollutant discharged from the lower air outlet chamber (b) of the adsorption tower (T1) passes through the third smoke The gas pipeline (L3) is sent to the inlet chamber (3') of the secondary adsorption tower (T2) and sequentially flows through one or more activated carbon beds of the secondary adsorption tower (T2) from the secondary adsorption tower (T2) The flue gas discharged from the outlet chamber (9) is sent to the flue gas in the second flue gas duct (L2) via the fourth flue gas duct (L4) and then discharged, from the first adsorption tower (T1) The flue gas discharged from the central air outlet chamber (c) is transported via the fifth flue gas duct (L5) and merged with the flue gas in the second flue gas duct (L2) or the third by switching of the switching valve (10), respectively. Flue gas pipeline (L3) The flue gas merges, and the activated carbon adsorbing the pollutants is discharged from the bottom of the secondary adsorption tower (T2); preferably, the first smoke of the diluted ammonia gas is introduced into the primary adsorption tower (T1) at the same time as the above operation. The gas line (L1) is neutralized and optionally passed into a third flue gas line (L3) conveying flue gas for the secondary adsorption column (T2) and optionally passed to the primary adsorption column (T1) and/or Within the secondary adsorption tower (T2).
The method according to any one of claims 8 to 11, wherein the residence time of the activated carbon in the activated carbon bed is adjusted by adjusting the discharge valve (5) at the bottom of the activated carbon bed of the adsorption column to ensure the adsorption column from the first stage ( In the upper outlet chamber (a) of T1) or in the upper part of the primary adsorption tower (T1) The content of contaminants in the flue gas discharged from chamber (a) and central outlet chamber (c) is within the scope of compliance with regulations or compliance with regulations.