CN112295354B - Regulation and control method for inhibiting SRG flue gas crystallization - Google Patents

Regulation and control method for inhibiting SRG flue gas crystallization Download PDF

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CN112295354B
CN112295354B CN201910692541.8A CN201910692541A CN112295354B CN 112295354 B CN112295354 B CN 112295354B CN 201910692541 A CN201910692541 A CN 201910692541A CN 112295354 B CN112295354 B CN 112295354B
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tower
pollutants
nitrogen dioxide
srg
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CN112295354A (en
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杨本涛
魏进超
李小龙
李俊杰
康建刚
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Zhongye Changtian International Engineering Co Ltd
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/02—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/8621—Removing nitrogen compounds
    • B01D53/8634—Ammonia
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/90—Injecting reactants
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/30—Processes for preparing, regenerating, or reactivating
    • B01J20/34—Regenerating or reactivating
    • B01J20/3416—Regenerating or reactivating of sorbents or filter aids comprising free carbon, e.g. activated carbon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/30—Processes for preparing, regenerating, or reactivating
    • B01J20/34—Regenerating or reactivating
    • B01J20/3483—Regenerating or reactivating by thermal treatment not covered by groups B01J20/3441 - B01J20/3475, e.g. by heating or cooling
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
    • B01D2253/10—Inorganic adsorbents
    • B01D2253/102—Carbon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/02—Other waste gases
    • B01D2258/0283—Flue gases
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2259/00—Type of treatment
    • B01D2259/40—Further details for adsorption processes and devices
    • B01D2259/40083—Regeneration of adsorbents in processes other than pressure or temperature swing adsorption
    • B01D2259/40088—Regeneration of adsorbents in processes other than pressure or temperature swing adsorption by heating
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters

Abstract

A regulation and control method for inhibiting SRG flue gas crystallization comprises the following steps: 1) adding the active carbon adsorbed with the pollutants into an analytical tower (1), and analyzing and regenerating the active carbon adsorbed with the pollutants in the analytical tower (1); 2) introducing a carrier gas containing nitrogen dioxide into the desorption tower (1), desorbing the active carbon adsorbed with the pollutants in the desorption tower (1) to release ammonia gas, reacting the nitrogen dioxide with the ammonia gas, and consuming the ammonia gas; 3) the activated carbon adsorbed with the pollutants is resolved in a resolving tower (1) to obtain fresh activated carbon and SRG gas. The invention eliminates NH in SRG gas by introducing nitrogen dioxide into the desorption tower3Thereby inhibiting the crystallization of ammonium chloride in the SRG gas and ensuring the stable operation of the active carbon flue gas purification system.

Description

Regulation and control method for inhibiting SRG flue gas crystallization
Technical Field
The invention relates to a method for preventing SRG gas (sulfur-rich gas) pipeline blockage, in particular to a regulation and control method for inhibiting SRG flue gas crystallization, and belongs to the field of chemical industry.
Background
The flue gas pollution emission control technology of the activated carbon utilizes the characteristics of rich functional groups and larger specific surface area of the activated carbon and can simultaneously remove SO2And pollutants such as NOx, dust, VOCs, heavy metals and the like, and the activated carbon with saturated adsorption can be recycled after regeneration, so that the method has a wide development prospect. Activated carbon cigaretteThe pneumatic control technology has been developed for more than fifty years so far, and a series of processes are developed at home and abroad successively, and representative processes comprise a Reinluft process, a Sumitomo process and a Westvaco process.
During the regeneration of the activated carbon, a sulfur-rich gas (SRG gas) having a high concentration is generated. The early detection result shows that the sulfur-rich gas contains pollutants such as ammonia gas, hydrogen chloride, dust and the like besides high-concentration sulfur dioxide. The ammonia gas is easy to generate gas-phase crystallization reaction with the hydrogen chloride under the conditions of low temperature and high concentration, so that ammonium chloride crystals are formed. Large-area crystallization can occur in SRG gas pipelines, so that blockage is caused, and serious influence is caused on an activated carbon flue gas purification system. Therefore, it can be said that the prevention of the formation of ammonium chloride crystals is a prerequisite for ensuring the normal operation of the activated carbon flue gas purification system. The method for preventing ammonium chloride from crystallizing commonly used in the industry at present mainly comprises heating or heat preservation treatment of SRG flue gas, but the method has the defects of high investment cost and unstable operation.
Disclosure of Invention
The method aims at solving the problem that the SRG gas generated by the existing activated carbon process is easy to cause ammonium chloride crystallization to block a pipeline, and the main reason is that the concentration of ammonia gas and hydrogen chloride gas in the SRG gas is high. According to the invention, a small amount of nitrogen dioxide is introduced as carrier gas in the desorption process of the active carbon adsorbing pollutants (sulfur dioxide, ammonia gas, hydrogen chloride and the like), and as the pollutants are adsorbed in the desorption tower, the active carbon can release the ammonia gas, and further, the nitrogen dioxide and the ammonia gas can carry out SCR reaction, so that the elimination of the ammonia gas is realized, the concentration of the ammonia gas in SRG flue gas is reduced, and the formation of ammonium chloride crystals is prevented.
According to the embodiment of the invention, a regulation and control method for inhibiting SRG flue gas crystallization is provided:
a regulation and control method for inhibiting SRG flue gas crystallization comprises the following steps:
1) adding the active carbon adsorbed with the pollutants into an analytical tower, and carrying out analysis and regeneration on the active carbon adsorbed with the pollutants in the analytical tower.
2) And introducing a carrier gas containing nitrogen dioxide into the desorption tower, desorbing the activated carbon adsorbed with the pollutants in the desorption tower to release ammonia gas, and reacting the nitrogen dioxide with the ammonia gas to consume the ammonia gas.
3) And the activated carbon adsorbed with the pollutants is resolved in a resolving tower to obtain fresh activated carbon and SRG gas.
In the invention, the step 2) of introducing the carrier gas containing nitrogen dioxide into the desorption tower specifically comprises the following steps: and introducing mixed gas of nitrogen dioxide and carrier gas into the top and/or the bottom of the desorption tower.
Preferably, the desorption tower is divided into a heating section, a transition section and a cooling section from top to bottom according to the trend of the activated carbon in the desorption tower, and mixed gas of nitrogen dioxide and carrier gas is introduced from the top of the heating section and/or the bottom of the cooling section of the desorption tower.
Preferably, the concentration of nitrogen dioxide in the mixed gas of nitrogen dioxide and carrier gas is 0.1-10%, preferably 0.3-8%, and more preferably 0.5-5%.
Preferably, the carrier gas is nitrogen or an inert gas. Preferably nitrogen or helium.
In the present invention, the method further comprises:
4) and (3) carrying out sulfur resource recovery on the SRG gas obtained in the step 3).
In the present invention, the method further comprises:
5) conveying the fresh activated carbon obtained in the step 3) to an activated carbon adsorption tower for treating the flue gas, absorbing pollutants in the flue gas, conveying the activated carbon with the adsorbed pollutants to an analytical tower for regeneration, and circulating the steps.
In the invention, the step 2) further comprises detecting the content of ammonia gas in the desorption tower, and calculating the amount of nitrogen dioxide required to be introduced into the desorption tower according to the content of ammonia gas in the desorption tower, specifically:
an ammonia gas concentration detection device is arranged on the side wall of the transition section of the desorption tower, a flowmeter is arranged at the SRG gas outlet of the desorption tower, and the ammonia gas concentration detection device detects that the concentration of ammonia gas in the desorption tower is CNH3The flow of SRG gas in the desorption tower measured by the flowmeter is Q0Thus, the amount M of nitrogen dioxide required to be introduced into the desorption towerNO2Comprises the following steps:
4×MNO2/46＝k×3×Q0×CNH3/17；
obtaining the following components: mNO2＝k×2.03×Q0×CNH3；
Wherein the amount of nitrogen dioxide required to be introduced into the desorption tower is MNO2Mg/h; flow rate of SRG gas is Q0，Nm3H; the concentration of ammonia gas in the desorption tower is CNH3，mg/Nm3(ii) a k is a constant having a value of 0.8 to 2, preferably 0.85 to 1.8, more preferably 0.9 to 1.6.
Preferably, the desorption tower in step 1) desorbs and regenerates the activated carbon adsorbed with the contaminants by heating. Preferably, the heating is performed by electric heating or hot air heating.
Preferably, the heating temperature is 200-600 ℃, preferably 250-520 ℃, more preferably 300-480 ℃, and further preferably 350-450 ℃.
In the present invention, the pollutant in the activated carbon adsorbed with pollutant in step 1) is derived from flue gas, preferably from sintering flue gas. Preferably, the flue gas comprises NOx and SO2One or more of dust, VOCs, heavy metals and halogens.
Preferably, the flue gas is nitrogen oxide-containing flue gas generated in one or more industries of steel, electric power, color, petrifaction, chemical industry and building materials.
Preferably, the temperature of the flue gas is 80-250 ℃, preferably 100-200 ℃, more preferably 120-180 ℃, and further preferably 130-160 ℃.
In the invention, the active carbon adsorbing the pollutants is sourced from an active carbon adsorption tower, and ammonia gas is sprayed into the active carbon in the process of adsorbing the pollutants in the adsorption tower. Preferably, the molar amount of the ammonia gas injected per unit time is 0.8 to 2 times, preferably 0.9 to 1.8 times, and more preferably 1.0 to 1.5 times the molar amount of NOx contained in the pollutants per unit time.
Preferably, the sulfur resource is recovered in step 4) by treating the SRG gas to produce sulfuric acid.
The invention provides a treatment method on the basis of a large amount of research and engineering practice, and provides a regulation and control method for inhibiting SRG flue gas crystallization, wherein the technological process and the technical principle are briefly described as follows:
1) adsorbing multi-pollutant flue gas by using activated carbon:
adsorbing ammonia: because the multi-pollutant flue gas contains nitrogen oxides, a certain amount of ammonia needs to be added, and in order to ensure the denitration efficiency, the molar quantity of the sprayed ammonia gas in unit time is 0.8-2 times, preferably 0.9-1.8 times, and more preferably 1.0-1.5 times (for example, 1.3 times) of the molar quantity of the nitrogen oxides contained in the pollutants in the unit time. The ammonia gas is easily absorbed by the active carbon, and the excessive ammonia gas is absorbed by the active carbon to form AC-NH3The substance of (1).
Absorbing hydrogen chloride: the flue gas contains a large amount of hydrogen chloride which is easily absorbed by active carbon to form an AC-HCl substance.
2) Activated carbon regeneration and ammonia elimination:
according to research results, the formed activated carbon adsorption substances can be resolved in a thermal regeneration mode to form NH respectively3、HCl；
(ii) No NO in the Carrier gas2When introduced, the SRG flue gas composition is mainly NH3And HCl, which is susceptible to the following processes that cause flue gas crystallization:
Figure BDA0002148318230000031
② NO in the carrier gas2When introduced, due to NO in the carrier gas2NH released by desorption with desorption tower3A reaction (i.e., SCR reaction) occurs to form nitrogen and water, the reaction process being as follows:
8NH3+6NO2→7N2+12H2O；
at this time NH3Is eliminated (or NH)3The content of (b) is very small), the composition of the SRG flue gas is mainly HCl, and the flue gas can not be crystallized. Compared with the prior art, on one hand, the SRG gas obtained in the step 3) of the invention has the characteristic of high sulfur content; all in oneAnd because the generation of crystals is inhibited, the SRG gas discharge pipeline can keep stable gas output, and the processing link can be monitored.
In addition, ammonium chloride belongs to a substance which is easily decomposed by heat, and the reaction formula of the decomposition of ammonium chloride is as follows: NH (NH)4Cl→NH3↓directionand × + HCl ×). When the activated carbon having adsorbed the contaminants is desorbed and regenerated in the desorption tower, ammonium chloride cannot be generated even when ammonia gas and hydrogen chloride gas come into contact with each other in a high-temperature environment. Meanwhile, due to the high-temperature environment of the activated carbon regeneration process, the nitrogen dioxide and the ammonia gas can better react, so that the reaction of the nitrogen dioxide and the ammonia gas is more sufficient.
According to the technical scheme, firstly, a chemical principle is used as a basis, nitrogen dioxide and ammonia gas react to generate nitrogen gas and water, and the generation of ammonium chloride is prevented; secondly, introducing mixed gas of nitrogen dioxide and carrier gas into the top of the heating section and/or the bottom of the cooling section of the desorption tower, so as to ensure that the nitrogen dioxide is fully contacted with ammonia gas released in the desorption process of the activated carbon and improve the removal efficiency of the ammonia gas; thirdly, the scheme of the invention ensures the smooth reaction of the nitrogen dioxide and the ammonia gas by utilizing the high-temperature environment of the activated carbon regeneration process; in addition, the SRG gas generated by the process has single impurity, and only a small amount of nitrogen dioxide except sulfide is generated, so that the difficulty in later-stage purification is reduced. The technical scheme of the invention can efficiently remove ammonia gas in SRG gas, inhibit the generation of ammonium chloride and ammonium sulfate, and has great significance for reducing sulfide loss, improving production efficiency and protecting equipment safety and stability.
Preferably, the ammonia concentration detection device is arranged on the side wall of the transition section of the desorption tower, the flowmeter is arranged at the SRG gas outlet, and the flow rate of the nitrogen dioxide required to be introduced into the desorption tower can be accurately calculated according to the flow rate of the SRG gas measured by the flowmeter and the concentration of the ammonia gas in the desorption tower measured by the ammonia concentration detection device. Meanwhile, the flow rate of the carrier gas containing the nitrogen dioxide to be introduced into the desorption tower can be calculated according to the calculated flow rate of the nitrogen dioxide to be introduced into the desorption tower and the concentration of the nitrogen dioxide in the mixed gas of the nitrogen dioxide and the carrier gas. Wherein, in the mixed gas of the nitrogen dioxide and the carrier gas, the concentration of the nitrogen dioxide is 0.1-10%, preferably 0.3-8%, and more preferably 0.5-5%. And a proper amount of carrier gas is introduced into the desorption tower, namely a proper amount of nitrogen dioxide is introduced, so that excessive cost is not increased while ammonia gas is eliminated, and nitrogen generated by SCR reaction of the nitrogen dioxide and the ammonia gas can also play a role in protecting the desorption process of the activated carbon together with the carrier gas. In the present invention, the carrier gas is nitrogen or an inert gas, preferably nitrogen or helium.
In addition, the traditional method for preventing ammonium chloride in the SRG gas from crystallizing is mainly to heat or preserve the SRG gas, the operation of the method is unstable, and the cost for subsequent washing and cooling of the SRG gas is higher due to the temperature rise of the SRG gas. Compared with the traditional method, the method utilizes the SCR denitration principle to eliminate the ammonia in the SRG gas, and does not need to heat or preserve the temperature of the SRG gas, so that the temperature of the SRG gas can be reduced, and the investment cost is reduced; meanwhile, the method has high controllability, and nitrogen generated by SCR reaction of nitrogen dioxide and ammonia can also be used as protective gas without secondary pollution.
In the present invention, ammonia gas reacts with nitrogen dioxide, so that ammonia gas does not form ammonium sulfate or ammonium bisulfate crystals with sulfides even at high temperatures. Therefore, the sulfur content of the SRG gas is high, and the loss of sulfur resources is reduced. Further, ammonium bisulfate and ammonium sulfate are easily decomposed by heat.
In the present invention, the contaminants in step 1) originate from flue gases, preferably from sintering flue gases. The invention scheme provided by the invention is suitable for treating the activated carbon with the adsorbed pollutant as smoke. Is more suitable for treating the activated carbon adsorbing the sintering flue gas. But does not exclude process schemes where the source of the contaminants is other gases or liquids.
In the present invention, the flue gas includes NOx and SO2One or more of dust, VOCs, heavy metals and halogens. The scheme of the invention is more effectively used for treating the activated carbon adsorbing the mixed flue gas. The ammonia gas reacts with the nitrogen dioxideIt is effective to prevent the generation of ammonium chloride crystals or ammonium sulfate crystals. The service life of the equipment is prolonged.
In the invention, the flue gas is flue gas containing nitrogen oxides generated in one or more industries of steel, electric power, nonferrous metals, petrifaction, chemical industry and building material industry. The method is more effective in treating the activated carbon of the flue gas adsorbed with the nitrogen oxides. The ammonia gas reacts with the nitrogen dioxide, i.e. effectively prevents the generation of ammonium chloride crystals or ammonium sulfate crystals. The service life of the equipment is prolonged.
In the invention, ammonia gas is sprayed in the process that the active carbon adsorbs pollutants in the adsorption tower. The injection of ammonia gas is beneficial to removing nitrogen oxides in pollutants. The nitrogen oxides react with ammonia gas to generate nitrogen gas and water.
In the invention, in order to ensure that the nitrogen oxides in the flue gas can completely react with the ammonia gas, the molar quantity of the injected ammonia gas in unit time can be adjusted according to the molar quantity of NOx contained in pollutants in unit time. Generally, the molar quantity of the injected ammonia gas in unit time is 0.8-2 times of the molar quantity of NOx contained in pollutants in unit time; preferably 0.9 to 1.8 times; more preferably 1.0 to 1.5 times.
In the invention, the adopted activated carbon regeneration process is a heating regeneration method. The heat regeneration method is the most applied and industrially most mature activated carbon regeneration method. The heating regeneration method has the characteristics of high regeneration efficiency and wide application range. There are various methods for regenerating activated carbon, for example: thermal regeneration, biological regeneration, wet oxidation, solvent regeneration, electrochemical regeneration, catalytic wet oxidation, and the like. Among them, the thermal regeneration method is most advantageous for the scheme of the present invention.
Ammonium chloride belongs to a substance which is easily decomposed by heating, and the chemical formula of the decomposition of the ammonium chloride is as follows: NH (NH)4Cl→NH3↓directionand × + HCl ×). When the activated carbon having adsorbed the contaminants is subjected to a regeneration process, ammonium chloride cannot be generated even when ammonia gas is brought into contact with hydrogen chloride gas in a high-temperature environment. Meanwhile, due to the high-temperature environment of the activated carbon regeneration process, the nitrogen dioxide and the ammonia gas can better react, so that the nitrogen dioxide and the ammonia gas can better reactThe reaction of ammonia is more complete. Therefore, the invention adopts the activated carbon heating regeneration method, so that the nitrogen dioxide and the ammonia gas can react more fully.
In the present invention, the heating method employs electric heating or hot air heating. According to the characteristics of different industrial production, a large amount of steam is generated in a part of factories for generating electricity, and the generated electricity can be used for electric heating. Or directly heating the activated carbon by using an electric heating body. Hot air can also be used as a heat-conducting medium for heating.
In the present invention, the temperature of the desorption/regeneration process is 200 to 600 ℃, preferably 250 to 520 ℃, more preferably 300 to 480 ℃, and still more preferably 350 to 450 ℃. And adjusting the temperature of the regeneration process according to the saturation degree of the activated carbon for adsorbing the pollutants, thereby adjusting the precipitation speed of the impurities in the activated carbon.
In the present application, the analysis and the desorption are the same concept. SRG flue gas is the same concept as SRG gas. A carrier gas containing nitrogen dioxide and a mixed gas of nitrogen dioxide and the carrier gas are equivalent concepts.
Compared with the prior art, the invention has the following beneficial effects:
1. the invention applies the SCR denitration principle to the active carbon analysis process of the analysis tower, introduces nitrogen dioxide into the carrier gas of the heating section and/or the cooling section of the analysis tower, and eliminates NH in SRG gas3Thereby inhibiting ammonium chloride crystallization in SRG gas and ensuring the stable operation of the activated carbon flue gas purification system;
2. the method has the advantages of simple application, obvious effect and less modification on the original activated carbon flue gas purification system;
3. after the invention is applied, the temperature of the SRG gas can be reduced, and the scale of the subsequent washing, cooling and purifying equipment of the SRG gas is further reduced, so that the investment cost is greatly reduced;
4. the method has the advantages of simple operation, high controllability, low cost and no secondary pollution.
Drawings
FIG. 1 is a flow chart of the activated carbon flue gas purification process of the present invention;
FIG. 2 is a schematic structural diagram of an activated carbon desorption device according to the present invention;
FIG. 3 is a schematic diagram of the activated carbon desorption process of the present invention.
Reference numerals: 1: a resolution tower; 101: a heating section; 102: a transition section; 103: a cooling section; 104: an SRG gas outlet; 2: a concentration detection device; 3: a flow meter.
Detailed Description
According to the embodiment of the invention, a regulation and control method for inhibiting SRG flue gas crystallization is provided:
a regulation and control method for inhibiting SRG flue gas crystallization comprises the following steps:
1) the active carbon adsorbing the pollutants is added into the desorption tower 1, and the active carbon adsorbing the pollutants is desorbed and regenerated in the desorption tower 1.
2) And introducing a carrier gas containing nitrogen dioxide into the desorption tower 1, desorbing the activated carbon adsorbed with the pollutants in the desorption tower 1 to release ammonia gas, and reacting the nitrogen dioxide with the ammonia gas to consume the ammonia gas.
3) The activated carbon having adsorbed the contaminants is desorbed in the desorption tower 1 to obtain fresh activated carbon and SRG gas.
In the invention, the step 2) of introducing the carrier gas containing nitrogen dioxide into the desorption tower 1 specifically comprises the following steps: and introducing mixed gas of nitrogen dioxide and carrier gas into the top and/or the bottom of the desorption tower 1.
Preferably, the desorption tower 1 is divided into a heating section 101, a transition section 102 and a cooling section 103 from top to bottom according to the trend of the activated carbon in the desorption tower 1, and the mixed gas of the nitrogen dioxide and the carrier gas is introduced from the top of the heating section 101 and/or the bottom of the cooling section 103 of the desorption tower 1.
Preferably, the concentration of nitrogen dioxide in the mixed gas of nitrogen dioxide and carrier gas is 0.1-10%, preferably 0.3-8%, and more preferably 0.5-5%.
Preferably, the carrier gas is nitrogen or an inert gas. Preferably nitrogen or helium.
In the present invention, the method further comprises:
4) and (3) carrying out sulfur resource recovery on the SRG gas obtained in the step 3).
In the present invention, the method further comprises:
5) conveying the fresh activated carbon obtained in the step 3) to an activated carbon adsorption tower for treating the flue gas, absorbing pollutants in the flue gas, conveying the activated carbon with the adsorbed pollutants to an analytical tower 1 for regeneration, and circulating the steps.
In the invention, the step 2) further comprises detecting the content of ammonia gas in the desorption tower 1, and calculating the amount of nitrogen dioxide required to be introduced into the desorption tower 1 according to the content of ammonia gas in the desorption tower 1, specifically:
an ammonia gas concentration detection device 2 is arranged on the side wall of the transition section 102 of the analysis tower 1, a flowmeter 3 is arranged at the SRG gas outlet 104 of the analysis tower 1, and the ammonia gas concentration detection device 2 detects that the concentration of ammonia gas in the analysis tower 1 is CNH3The flow rate of the SRG gas in the analysis tower 1 measured by the flow meter 3 is Q0Thus, the amount M of nitrogen dioxide required to be introduced into the desorption tower 1NO2Comprises the following steps:
4×MNO2/46＝k×3×Q0×CNH3/17；
obtaining the following components: mNO2＝k×2.03×Q0×CNH3；
Wherein the amount of nitrogen dioxide required to be introduced into the desorption tower 1 is MNO2Mg/h; flow rate of SRG gas is Q0，Nm3H; the concentration of ammonia gas in the stripping tower 1 is CNH3，mg/Nm3(ii) a k is a constant with a value of 0.8 to 2.
Preferably, in the desorption tower 1) in the step 1), the activated carbon adsorbed with the contaminants is desorbed and regenerated by heating. Preferably, the heating is performed by electric heating or hot air heating.
Preferably, the heating temperature is 200-600 ℃, preferably 250-520 ℃, more preferably 300-480 ℃, and further preferably 350-450 ℃.
In the present invention, the pollutant in the activated carbon adsorbed with pollutant in step 1) is derived from flue gas, preferably from sintering flue gas. Preferably, the flue gas comprises NOx and SO2Dust, VOOne or more of Cs, heavy metals and halogens.
Preferably, the flue gas is nitrogen oxide-containing flue gas generated in one or more industries of steel, electric power, color, petrifaction, chemical industry and building materials.
Preferably, the temperature of the flue gas is 80-250 ℃, preferably 100-200 ℃, more preferably 120-180 ℃, and further preferably 130-160 ℃.
In the invention, the active carbon adsorbing the pollutants is sourced from an active carbon adsorption tower, and ammonia gas is sprayed into the active carbon in the process of adsorbing the pollutants in the adsorption tower. Preferably, the molar amount of the ammonia gas injected per unit time is 0.8 to 2 times, preferably 0.9 to 1.8 times, and more preferably 1.0 to 1.5 times the molar amount of NOx contained in the pollutants per unit time.
Preferably, the sulfur resource is recovered in step 4) by treating the SRG gas to produce sulfuric acid.
Example 1
A regulation and control method for inhibiting SRG flue gas crystallization comprises the following steps:
1) the active carbon adsorbing the pollutants is added into the desorption tower 1, and the active carbon adsorbing the pollutants is desorbed and regenerated in the desorption tower 1.
2) And introducing a carrier gas containing nitrogen dioxide into the desorption tower 1, desorbing the activated carbon adsorbed with the pollutants in the desorption tower 1 to release ammonia gas, and reacting the nitrogen dioxide with the ammonia gas to consume the ammonia gas.
3) The activated carbon having adsorbed the contaminants is desorbed in the desorption tower 1 to obtain fresh activated carbon and SRG gas.
Example 2
A regulation and control method for inhibiting SRG flue gas crystallization comprises the following steps:
1) the active carbon adsorbing the pollutants is added into the desorption tower 1, and the active carbon adsorbing the pollutants is desorbed and regenerated in the desorption tower 1.
Wherein: the analysis and regeneration mode is hot air heating regeneration. The heating temperature was 480 ℃. The pollutants adsorbed by the activated carbon are derived from sintering flue gas.Wherein the sintering flue gas comprises NOx and SO2Dust, VOCs, heavy metals, halogens and the like. The temperature of the flue gas was 160 ℃.
2) And introducing mixed gas of nitrogen dioxide and nitrogen into the top of the heating section 101 of the desorption tower 1, desorbing the active carbon adsorbed with the pollutants in the desorption tower 1 to release ammonia gas, and reacting the nitrogen dioxide with the ammonia gas to consume the ammonia gas.
Wherein: the carrier gas is nitrogen. The concentration of nitrogen dioxide in the mixed gas of nitrogen dioxide and nitrogen gas is 2.5%.
The method also comprises the steps of detecting the content of the ammonia gas in the analysis tower 1, and calculating the amount of the nitrogen dioxide required to be introduced into the analysis tower 1 according to the content of the ammonia gas in the analysis tower 1, and specifically comprises the following steps:
an ammonia gas concentration detection device 2 is arranged on the side wall of the transition section 102 of the analysis tower 1, a flowmeter 3 is arranged at the SRG gas outlet 104 of the analysis tower 1, and the ammonia gas concentration detection device 2 detects that the concentration of ammonia gas in the analysis tower 1 is CNH3＝5100mg/Nm3The flow rate of the SRG gas in the analysis tower 1 measured by the flow meter 3 is Q0＝970Nm3H, the amount M of nitrogen dioxide to be introduced into the desorption tower 1NO2Comprises the following steps:
4×MNO2/46＝k×3×Q0×CNH3/17；
obtaining the following components: mNO2＝k×2.03×Q0×CNH3＝9.24×106mg/h；
Wherein the amount of nitrogen dioxide required to be introduced into the desorption tower 1 is MNO2Mg/h; SRG gas flow is M0，Nm3H; the concentration of ammonia gas in the stripping tower 1 is CNH3，mg/Nm3(ii) a k is a constant with a value of 0.92.
3) The activated carbon having adsorbed the contaminants is desorbed in the desorption tower 1 to obtain fresh activated carbon and SRG gas.
Example 3
Example 2 was repeated except that a mixed gas of nitrogen dioxide and a carrier gas was introduced into both the top of the heating section 101 and the bottom of the cooling section 103 of the desorption tower 1 in step 2).
Example 4
Example 2 is repeated except that the method further comprises: 4) and (3) carrying out sulfur resource recovery on the SRG gas obtained in the step 3). Wherein the sulfur resource recovery is to carry out sulfuric acid preparation treatment on the SRG gas.
Example 5
Example 4 is repeated except that the method further comprises: 5) conveying the fresh activated carbon obtained in the step 3) to an activated carbon adsorption tower for treating the flue gas, absorbing pollutants in the flue gas, conveying the activated carbon with the adsorbed pollutants to an analytical tower 1 for regeneration, and circulating the steps.
Example 6
Example 5 is repeated, except that the activated carbon adsorbing the pollutants in the step 1) is sourced from an activated carbon adsorption tower, and ammonia gas is sprayed in the process of adsorbing the pollutants in the adsorption tower by the activated carbon. The molar quantity of the injected ammonia gas in unit time is 1.3 times of the molar quantity of NOx contained in pollutants in unit time
Example 7
Example 6 was repeated except that the concentration of nitrogen dioxide in the mixed gas of nitrogen dioxide and nitrogen in step 2) was 0.5%.
Example 8
Example 6 was repeated except that the activated carbon was analyzed and regenerated in step 1) by electric heating. The heating temperature was 350 ℃. The pollutants adsorbed by the activated carbon are derived from flue gas containing nitrogen oxides generated in the steel industry. The temperature of the flue gas was 130 ℃.
Example 9
Example 6 was repeated except that, during the adsorption of the contaminants by the activated carbon in the adsorption column, ammonia gas was injected in a molar amount of 1.8 times the molar amount of NOx contained in the contaminants per unit time.
The concentration detection of ammonia gas is carried out on SRG gas generated by treating flue gas of a certain steel plant by adopting the prior art and SRG gas generated by treating flue gas of the steel plant by adopting the technical scheme of the invention, and the results are as follows:
content of Ammonia gas
SRG gas produced by adopting the prior art About 1000 to 20000mg/Nm3
SRG gas generated by adopting the technical scheme of the invention ＜50mg/Nm3

Claims (28)

1. A regulation and control method for inhibiting SRG flue gas crystallization comprises the following steps:
1) adding the active carbon adsorbed with the pollutants into an analytical tower (1), and analyzing and regenerating the active carbon adsorbed with the pollutants in the analytical tower (1);
2) introducing a carrier gas containing nitrogen dioxide into the desorption tower (1), desorbing the active carbon adsorbed with the pollutants in the desorption tower (1) to release ammonia gas, reacting the nitrogen dioxide with the ammonia gas, and consuming the ammonia gas;
3) the activated carbon adsorbed with the pollutants is resolved in a resolving tower (1) to obtain fresh activated carbon and SRG gas.
2. The method of claim 1, wherein: in the step 2), introducing a carrier gas containing nitrogen dioxide into the desorption tower (1), specifically: and introducing mixed gas of nitrogen dioxide and carrier gas into the top and/or the bottom of the desorption tower (1).
3. The method of claim 2, wherein: according to the trend of the activated carbon in the desorption tower (1), the desorption tower (1) is divided into a heating section (101), a transition section (102) and a cooling section (103) from top to bottom, and mixed gas of nitrogen dioxide and carrier gas is introduced from the top of the heating section (101) and/or the bottom of the cooling section (103) of the desorption tower (1).
4. The method of claim 2, wherein: in the mixed gas of the nitrogen dioxide and the carrier gas, the concentration of the nitrogen dioxide is 0.1-10%; and/or
The carrier gas is nitrogen or inert gas.
5. The method of claim 2, wherein: in the mixed gas of the nitrogen dioxide and the carrier gas, the concentration of the nitrogen dioxide is 0.3-8%; and/or
The carrier gas is nitrogen or helium.
6. The method of claim 2, wherein: and in the mixed gas of the nitrogen dioxide and the carrier gas, the concentration of the nitrogen dioxide is 0.5-5%.
7. The method according to any one of claims 1-6, wherein: the method further comprises the following steps:
4) and (3) carrying out sulfur resource recovery on the SRG gas obtained in the step 3).
8. The method of claim 7, wherein: the method further comprises the following steps:
5) conveying the fresh activated carbon obtained in the step 3) to an activated carbon adsorption tower for treating the flue gas, absorbing pollutants in the flue gas, conveying the activated carbon with the adsorbed pollutants to an analytical tower (1) for regeneration, and circulating the steps.
9. The method according to any one of claims 1-6, 8, wherein: the step 2) also comprises the steps of detecting the content of the ammonia gas in the analysis tower (1), and calculating the amount of the nitrogen dioxide required to be introduced into the analysis tower (1) according to the content of the ammonia gas in the analysis tower (1), wherein the steps specifically comprise:
in the stripping column (1)An ammonia gas concentration detection device (2) is arranged on the side wall of the transition section (102), a flowmeter (3) is arranged at the SRG gas outlet (104) of the desorption tower (1), and the ammonia gas concentration detection device (2) detects that the concentration of ammonia gas in the desorption tower (1) is CNH3The flow rate of the SRG gas in the desorption tower (1) measured by the flowmeter (3) is Q0Whereby the amount M of nitrogen dioxide required to be introduced into the desorption column (1)NO2Comprises the following steps:
4×MNO2/46＝k×3×Q0×CNH3/17；
obtaining the following components: mNO2＝k×2.03×Q0×CNH3；
Wherein the amount of nitrogen dioxide required to be introduced into the desorption tower (1) is MNO2Mg/h; flow rate of SRG gas is Q0，Nm3H; the concentration of ammonia gas in the desorption tower (1) is CNH3，mg/Nm3(ii) a k is a constant with a value of 0.8 to 2.
10. The method of claim 7, wherein: the step 2) also comprises the steps of detecting the content of the ammonia gas in the analysis tower (1), and calculating the amount of the nitrogen dioxide required to be introduced into the analysis tower (1) according to the content of the ammonia gas in the analysis tower (1), wherein the steps specifically comprise:
an ammonia concentration detection device (2) is arranged on the side wall of a transition section (102) of the analysis tower (1), a flowmeter (3) is arranged at the position of an SRG gas outlet (104) of the analysis tower (1), and the ammonia concentration detection device (2) detects that the concentration of ammonia in the analysis tower (1) is CNH3The flow rate of the SRG gas in the desorption tower (1) measured by the flowmeter (3) is Q0Whereby the amount M of nitrogen dioxide required to be introduced into the desorption column (1)NO2Comprises the following steps:
4×MNO2/46＝k×3×Q0×CNH3/17；
obtaining the following components: mNO2＝k×2.03×Q0×CNH3；
Wherein the amount of nitrogen dioxide required to be introduced into the desorption tower (1) is MNO2Mg/h; flow rate of SRG gas is Q0，Nm3H; the concentration of ammonia gas in the desorption tower (1) is CNH3，mg/Nm3(ii) a k is a constant with a value of 0.8 to 2.
11. The method of any one of claims 1-6, 8, 10, wherein: in the step 1), the desorption tower (1) is used for desorbing and regenerating the active carbon adsorbed with the pollutants in a heating mode.
12. The method of claim 11, wherein: the heating mode is electric heating or hot air heating.
13. The method of claim 11, wherein: the heating temperature is 200-600 ℃.
14. The method of claim 11, wherein: the heating temperature is 250-520 ℃.
15. The method of claim 11, wherein: the heating temperature is 300-480 ℃.
16. The method of claim 11, wherein: the heating temperature is 350-450 ℃.
17. The method of any one of claims 1-6, 8, 10, 12-16, wherein: the pollutants in the activated carbon adsorbed with pollutants in the step 1) are originated from flue gas.
18. The method of claim 17, wherein: the pollutants in the activated carbon adsorbed with pollutants in the step 1) are originated from sintering flue gas.
19. The method of claim 17, wherein: the flue gas comprises NOx and SO2One or more of dust, VOCs, heavy metals and halogens.
20. The method of claim 17, wherein: the flue gas is flue gas containing nitrogen oxides generated in one or more industries of steel, electric power, nonferrous metals, petrifaction, chemical industry and building materials; and/or
The temperature of the flue gas is 80-250 ℃.
21. The method of claim 17, wherein: the temperature of the flue gas is 100-200 ℃.
22. The method of claim 17, wherein: the temperature of the flue gas is 120-180 ℃.
23. The method of claim 17, wherein: the temperature of the flue gas is 130-160 ℃.
24. The method according to any one of claims 20-23, wherein: the active carbon adsorbing the pollutants is from an active carbon adsorption tower, and ammonia gas is sprayed into the active carbon in the process of adsorbing the pollutants in the adsorption tower.
25. The method of claim 24, wherein: the molar weight of the ammonia gas sprayed in unit time is 0.8-2 times of the molar weight of NOx contained in the pollutants in unit time.
26. The method of claim 24, wherein: the molar weight of the ammonia gas sprayed in unit time is 0.9-1.8 times of the molar weight of NOx contained in the pollutants in unit time.
27. The method of claim 24, wherein: the molar weight of the ammonia gas sprayed in unit time is 1.0-1.5 times of the molar weight of NOx contained in the pollutants in unit time.
28. The method of claim 7, wherein: and 4) recovering the sulfur resource in step 4) to prepare sulfuric acid from the SRG gas.
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CN202438327U (en) * 2012-02-29 2012-09-19 上海克硫环保科技股份有限公司 Heat-exchange type active coke purification and regeneration system
CN203593735U (en) * 2013-11-22 2014-05-14 上海国际化建工程咨询公司 Device for treating low temperature methanol washing ammonium crystallization and purifying barren liquor methanol
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