Alcohol amine liquid, device and method for decarburization of high-dust gas

Abstract

The invention provides alcohol amine liquid, a device and a method for decarburization of high-dust gas, and belongs to the technical field of low-carbon metallurgical decarburization in the metallurgical industry. Wherein the alcohol amine liquid comprises alcohol amine, an activating agent, a flocculating agent, a defoaming agent and water; the alcohol amine is selected from one or more of primary alcohol amine, secondary alcohol amine, tertiary alcohol amine or sterically hindered alcohol amine; the activating agent is selected from one or more of piperazine, diethanol amine, diethylenetriamine and diisopropanolamine; the flocculating agent is an inorganic flocculating agent, an organic flocculating agent or a composite flocculating agent composed of the inorganic flocculating agent and the organic flocculating agent; the defoaming agent is a composite defoaming agent consisting of one or more of a non-silicon type, an organic silicon type, a polyether type and a polyether modified organic silicon type. According to the developed alcohol amine liquid, the high-dust gas is carried into the alcohol amine liquid, dust is removed, and the influence of the dust on bubbles is eliminated, so that decarburization treatment on the high-dust gas by using an alcohol amine decarburization method is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of low-carbon metallurgical decarburization in the metallurgical industry, and in particular relates to an alcohol amine liquid, a device and a method for decarburization of high-dust gas. Background Art

[0002] The alcohol amine decarbonization method removes carbon dioxide by utilizing the principle of absorption and desorption of carbon dioxide in gas by alcohol amine liquid. The alcohol amine decarbonization has a high absorption rate and a large absorption capacity. It is a very important decarbonization technology with very important uses. It is widely used in the decarbonization treatment of flue gas, natural gas, coal gas and other gases.

[0003] The basic principle process of the alcohol amine decarbonization method and carbon dioxide absorption and desorption is shown in the following formula (taking the primary alcohol amine method as an example):

[0004] Absorption reaction:

[0005] Alcoholamine solution (RNH2, R is an alcohol group) first reacts with CO2 to form a zwitterionic salt RNH2 + COO -

[0006]

[0007] Zwitterion RNH2 + COO - Further react with alcohol amine solution to generate carbamic acid organic amine salt RNH3 + RNHCOO - (This is the rate-controlling step)

[0008]

[0009] Desorption reaction:

[0010] Carbamic acid organic amine salt RNH3 + RNHCOO - First desorbed to zwitterion RNH2 + COO - , and releases an olamine

[0011]

[0012] Zwitterion RNH2 + COO - Further desorption into alcohol amine and CO2

[0013]

[0014] The specific process is that the carbon dioxide in the gas is first absorbed by the alcoholamine liquid under pressure and low temperature in the absorption device, and reacts with the alcoholamine to generate organic amine salt of carbamate, thereby removing the carbon dioxide in the gas; after the absorption reaction, the generated organic amine salt of carbamate enters the desorption regeneration device for decompression and heating to generate a desorption reaction opposite to the absorption reaction, thereby dissociating into alcoholamine liquid and carbon dioxide, the dissociated carbon dioxide is collected and centrally processed, and the alcoholamine liquid is re-added to the absorption device for recycling.

[0015] Even though the traditional alcohol amine solution decarbonization technology has been widely used in the energy and chemical fields, it is used for the first time in the special field of metallurgy. Due to the particularity of the gas source and the limitations of related processes, the traditional alcohol amine solution decarbonization technology cannot fully meet the decarbonization requirements in the metallurgical field, which is particularly reflected in the following aspects:

[0016] 1. The dust content of process gas in the metallurgical industry is high and the components are complex. The dust carries active metal components to form substances with similar toxic activity, which not only easily causes the solvent to foam, but also causes the amine solution to degrade seriously under the toxic effect of impurity elements such as iron and manganese loaded by the dust, further deepening the foaming tendency;

[0017] 2. Blast furnace gas in the metallurgical industry is prone to carry trace organic matter. The presence and enrichment of trace organic matter can easily cause the amine liquid to foam, affecting the decarbonization efficiency and energy consumption.

[0018] The foaming property and foam stability of alcohol amine liquid are related to the aggregation of solid particles at the gas-liquid interface. Solid particles aggregated in the bubble liquid film increase the surface viscosity and the resistance of liquid flow in the liquid film, slowing down the drainage of the liquid film, making the bubbles difficult to break; the particle density is small, most of them can float on the water surface, and their wettability is poor, the wetting angle is large, and they are easily adhered by bubbles and aggregated in the bubble liquid film, making the bubbles relatively stable. In particular, fine particle dust (50μm) has a greater impact on foaming, and is extremely difficult to remove by conventional methods such as filtration, and is enriched in alcohol amine liquid. Therefore, alcohol amine liquid should have the performance of inhibiting or even eliminating the impact of dust on its foaming.

[0019] At present, the main way to inhibit foaming of alcohol amine liquid is to eliminate the foaming of alcohol amine liquid by changing the surface tension of the amine liquid through the defoamer component in the amine liquid, which cannot eliminate the influence of dust brought in by the gas on its foaming.

[0020] Therefore, in order to realize the use of alcohol amine decarbonization method to remove carbon dioxide from gases with high dust content such as blast furnace gas, it is necessary to develop alcohol amine liquid that can eliminate the effect of dust on foaming.

[0021] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0022] In order to solve the problems of foaming and serious degradation in the existing decarbonization methods of high-dust gas due to the particularity of the gas source in the prior art, an alcohol amine liquid, device and method for decarbonization of high-dust gas are provided. The alcohol amine liquid is used to remove dust in the decarbonization system, reduce or even eliminate the effect of dust on the foaming of the alcohol amine liquid, and can achieve the removal of carbon dioxide in high-dust gas such as blast furnace gas.

[0023] The first aspect of the present invention provides an alcoholamine liquid for decarbonization of high-dust gas, comprising: alcoholamine, activator, flocculant, defoamer and water;

[0024] The alcoholamine is a substance that undergoes adsorption or desorption reaction with carbon dioxide, and the alcoholamine is selected from one or more of primary alcoholamine, secondary alcoholamine, tertiary alcoholamine or hindered alcoholamine; preferably MDEA or sterically hindered alcoholamine or a mixture of multiple alcoholamines having a high-efficiency decarbonization effect;

[0025] The activator is a substance that improves and promotes the reaction of the alcohol amine component with carbon dioxide, and the activator is selected from one or more of piperazine (PZ), diethanolamine (DEA), diethylenetriamine (DETA), and diisopropanolamine (DIPA), preferably piperazine;

[0026] The flocculant is a physical method that can cause dust particles and impurities in the alcohol amine liquid to flocculate and precipitate and separate from the liquid phase by changing the electronegativity or surface tension of the alcohol amine liquid rather than by chemical reaction. The flocculant is an inorganic flocculant, an organic flocculant, or a composite flocculant composed of an inorganic flocculant and an organic flocculant.

[0027] The inorganic flocculant is mainly an inorganic compound or an inorganic polymer. The inorganic flocculant is selected from one or more of an iron-based flocculant, an aluminum-based flocculant, a poly-iron-based flocculant, a poly-aluminum-based flocculant or a poly-silicon-based flocculant and modified polymer flocculants, preferably a polymer flocculant; the organic flocculant is mainly an organic polymer compound, which can be a microbial flocculant or an organic polymer flocculant, preferably an organic polymer flocculant; organic polymer flocculants can be divided into natural organic polymer flocculants or synthetic organic polymer flocculants according to their sources, and natural organic polymer flocculants are based on natural organic polymer substances and are made by chemical treatment to increase active functional groups; synthetic organic polymer flocculants are obtained by artificial synthesis, preferably synthetic organic polymer flocculants; organic polymer flocculants can be divided into polyamine type, quaternary ammonium type and acrylamide copolymer type flocculants according to their chemical structure, preferably acrylamide copolymer type flocculants;

[0028] The defoamer is a substance that can inhibit and eliminate the generation of bubbles in liquid. The defoamer is a composite defoamer composed of one or more types of non-silicon type, silicone type, polyether type and polyether modified silicone type, such as lauric acid, silicone ether and silicone.

[0029] In some embodiments, the mass ratio of the alcoholamine in the alcoholamine solution is 10%-50%, preferably 20%, 30% or 40%;

[0030] The mass ratio of the activator in the alcohol amine solution is 1%-10%, preferably 2%, 3%, 4% or 5%;

[0031] The mass ratio of the flocculant in the alcohol amine solution is 1-10%, preferably 2%, 3%, 4% or 5%;

[0032] The mass ratio of the defoamer in the alcohol amine solution is 1-10%, preferably 2%, 3%, 4% or 5%.

[0033] The second aspect of the present invention provides a device for decarbonizing high-dust gas, comprising an alcohol amine liquid preparation device, an absorption tower, a solid-liquid separation device, and a desorption regeneration tower;

[0034] The alcohol amine liquid outlet is connected to the spray device in the absorption tower, the bottom outlet of the absorption tower is connected to the inlet of the solid-liquid separation device, the solid-liquid separation device outlet is connected to the upper inlet of the desorption regeneration tower, and the bottom outlet of the desorption regeneration tower is connected to the spray device in the absorption tower.

[0035] In some embodiments, the top of the absorption tower is provided with a purified gas outlet, and the top of the desorption regeneration tower is provided with a CO2 waste gas outlet;

[0036] And / or, the absorption tower and the desorption regeneration tower are respectively provided with a pressure monitoring device.

[0037] In some embodiments, the solid-liquid separation device includes one or several solid-liquid separation devices connected in series.

[0038] In some embodiments, the solid-liquid separation device is a solid-liquid classification device using a filtering method, and after filtering, the filtered matter is scraped off and removed from the filter screen or filter membrane.

[0039] In some embodiments, the device is provided with a driving pump for driving the circulation flow of the liquid in the device.

[0040] A third aspect of the present invention provides a method for decarbonizing high-dust gas, comprising:

[0041] S1: spraying the alcoholamine liquid in the alcoholamine preparation device into the absorption tower through the spraying device at the top of the absorption tower, and fully mixing the alcoholamine liquid with the high-dust gas added from the bottom of the absorption tower to obtain purified gas and carbamate organic amine salt, and the purified gas is discharged through the purified gas outlet at the top of the absorption tower;

[0042] S2: The carbamate organic amine salt enters the solid-liquid separation device from the bottom outlet of the absorption tower, and the liquid obtained by the solid-liquid separation device enters the desorption regeneration tower from the upper inlet of the desorption regeneration tower for desorption and separation, and the generated carbamate organic amine salt is re-desorbed into carbon dioxide waste gas and regenerated alcohol amine liquid with low carbon dioxide content;

[0043] S3: The regenerated alcohol amine solution is circulated to the spray device at the top of the absorption tower, and the above step S1 is repeated.

[0044] In some embodiments, the preparation method of the alcoholamine solution comprises: adding an activator to an alcoholamine aqueous solution, stirring and mixing, adding a flocculant and a defoamer, and mixing evenly to obtain the alcoholamine solution;

[0045] The mass ratio of the alcoholamine in the alcoholamine solution is 10%-50%, preferably 20%, 30% or 40%;

[0046] The mass ratio of the activator in the alcohol amine solution is 1%-10%, preferably 2%, 3%, 4% or 5%;

[0047] The mass ratio of the flocculant in the alcohol amine solution is 1-10%, preferably 2%, 3%, 4% or 5%;

[0048] The mass ratio of the defoamer in the alcohol amine solution is 1-10%, preferably 2%, 3%, 4% or 5%.

[0049] In some embodiments, the flow rate of the alcohol amine liquid sprayed into the absorption tower is determined according to the amount of dust gas to be processed, the CO2 content in the gas, and the effective components in the alcohol amine liquid, that is, according to the total amount of carbon dioxide to be processed and the effective components required to absorb the carbon dioxide. For example, if the flow rate is 266 t / h, the gas flow rate is 20000 Nm 3 / h, the CO2 content in the gas is 50vol.%, and the content of the main component amine (MDEA) in the amine liquid is 20%. The gas processing capacity and its carbon dioxide content vary greatly in different production occasions, so there is no specific limitation and it is determined according to the specific production occasion.

[0050] Compared with the prior art, the technical effects achieved by the present invention are as follows:

[0051] By using the alcoholamine liquid developed by the present invention, dust can be completely separated and removed from the alcoholamine liquid under the action of a flocculant, thereby avoiding the enrichment of the alcoholamine liquid and the deterioration of the foaming phenomenon during long-term operation, and at the same time, the bubbles in the alcoholamine liquid can be completely removed under the action of a defoamer. The high-dust gas is carried into the alcoholamine liquid to remove dust and eliminate the influence of dust on bubbles, thereby realizing the decarbonization treatment of the high-dust gas by the alcoholamine decarbonization method and improving the long-term stable operation of the gas decarbonization device. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a schematic diagram of the device and process flow for decarbonizing high-dust gas of the present invention;

[0053] Figure 2 This is a schematic diagram of the decarburization device and process flow in Comparative Example 1;

[0054] In the figure:

[0055] 1. Alcoholamine liquid preparation device; 2. Absorption tower; 3. Liquid-solid separation device; 4. Desorption regeneration tower;

[0056] a. Alkanolamine component; b. water; c. activator; d. flocculant; e. defoamer; f. prepared fresh alkanolamine solution; g. alkanolamine solution (lean solution); h. high-dust gas; i. purified gas; j. alkanolamine solution after absorbing carbon dioxide and dust; k. dust; m. dust-free alkanolamine solution; n. carbon dioxide waste gas; p. regenerated alkanolamine solution (lean solution). DETAILED DESCRIPTION

[0057] The technical solution of the present invention is described below by specific embodiments in conjunction with the accompanying drawings. It should be understood that one or more steps mentioned in the present invention do not exclude the existence of other methods and steps before and after the combination step, or other methods and steps can be inserted between these explicitly mentioned steps. It should also be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. Unless otherwise specified, the numbering of each method step is only for the purpose of identifying each method step, and is not intended to limit the order of arrangement of each method or to define the scope of implementation of the present invention. Changes or adjustments in their relative relationships can also be regarded as the scope of implementation of the present invention without substantial changes in the technical content.

[0058] The sources of the raw materials and instruments used in the examples are not particularly limited and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0059] In one embodiment, the invention provides a method for preparing an alcohol amine solution for decarbonization of high-dust gas. The principle of eliminating dust by the alcohol amine solution of the present invention is to add a flocculant to flocculate and enrich the dust in the alcohol amine solution and remove it from the alcohol amine solution. The preparation method is:

[0060] A certain amount of alcoholamine component a is added into the alcoholamine liquid preparation device 1, and a certain amount of water b is added at the same time and stirred sufficiently to be fully mixed to form an alcoholamine aqueous solution; a certain amount of activator c is added to the alcoholamine aqueous solution, stirred sufficiently to be mixed to form an alcoholamine aqueous solution with decarbonization activity; a certain amount of flocculant d and defoamer e are added to the alcoholamine aqueous solution, stirred sufficiently to be mixed, thereby forming a defoamable alcoholamine liquid f that can eliminate the influence of dust on foaming.

[0061] In one embodiment, the method for preparing the alcohol amine solution is as follows (combined with Figure 2 ):

[0062] The alcohol amine liquid (lean liquid, g) with low carbon dioxide content added from the upper part of the absorption tower 2 is fully mixed with the high dust gas h added from the lower part of the tower, and absorbs the carbon dioxide component in the high dust gas to generate carbamic acid organic amine salt, removes carbon dioxide gas from the gas, and also removes dust from the gas by elution and absorption into the liquid phase. The gas with carbon dioxide and dust removed is discharged from the top of the absorption tower 2 as purified gas i; and the alcohol amine liquid (j) after absorbing carbon dioxide and dust is discharged from the bottom of the absorption tower 2.

[0063] The alcoholamine liquid j after absorbing carbon dioxide and dust discharged from the bottom of the absorption tower 2 is added to the liquid-solid separation device 3 for liquid-solid separation. In the liquid-solid separation process, not only the larger dust particles are deposited from the alcoholamine liquid under the action of gravity sedimentation, but also the fine dust particles that are difficult to be flocculated and aggregated into blocks under the action of natural forces are deposited from the alcoholamine liquid under the action of flocculants, thereby completely depositing the dust in the alcoholamine liquid from the alcoholamine liquid to form an immiscible alcoholamine liquid phase and a dust solid phase, and under the action of the flocculant, the dust solid phase exists in the form of slurry lumps. Under the action of the flocculant, the dust solid phase in the form of slurry lumps can be separated by conventional separation methods such as filtration and plate filtration, thereby completely separating all the dust k in the alcoholamine liquid.

[0064] The liquid-solid separation method may be gravity sedimentation, filtration, plate filtration or other methods, or one or more combined separation methods, preferably filtration separation.

[0065] The dedusted alcoholamine liquid m from which dust impurities are completely removed enters the desorption regeneration tower 4 for desorption separation, and the generated carbamic acid organic amine salt is re-desorbed into carbon dioxide waste gas n and regenerated alcoholamine liquid (lean liquid, p) with low carbon dioxide content.

[0066] The generated carbon dioxide waste gas n is discharged from the top of the desorption regeneration tower 4 and then processed centrally; while the alcohol amine liquid p is returned to the absorption tower 2 for recycling. Since all dust is completely removed, the influence of dust on foaming is eliminated during the recycling of the alcohol amine liquid. When the alcohol amine liquid is insufficient, fresh alcohol amine liquid f is added to supplement it.

[0067] Example 1

[0068] In this embodiment, a new alcohol amine solution with a dust content of 50 mg / Nm 3 The decarbonization of blast furnace gas with a carbon dioxide content of 20% is described in detail as an example.

[0069] Among them, the dust content of 50μm~1mm and ≯50μm (≤50μm) is 30mg / Nm 3 and 20mg / Nm 3 .

[0070] Decarbonization device and decarbonization process of blast furnace gas Figure 1 As shown, the details are as follows:

[0071] A certain amount of ethanolamine component a (MDEA) is added to the ethanolamine liquid preparation device 1, and a certain amount of water b is added and stirred to form an ethanolamine aqueous solution; a certain amount of activator c (PZ) is added to the ethanolamine aqueous solution, and stirred to form an ethanolamine aqueous solution with decarbonization activity; a certain amount of flocculant d (inorganic iron-based flocculant ferric chloride) and defoamer e (lauric acid) are added to the ethanolamine aqueous solution, and stirred to form a defoamable ethanolamine liquid f that eliminates the effect of dust on foaming. The composition of the prepared ethanolamine liquid is shown in Table 1.

[0072] Table 1 Alcoholamine liquid composition

[0073] Components Alkylamine (MDEA) water Activator (PZ) Defoaming agent (lauric acid) Flocculant (ferric chloride) content / % 20 65 5 5 5

[0074] The alcoholamine liquid (lean liquid, g) with low carbon dioxide content added from the spray device (not shown) at the top of the absorption tower 2 is fully mixed with the high dust gas h (blast furnace gas) added from the bottom of the absorption tower, and absorbs the carbon dioxide component in the high dust gas to generate carbamic acid organic amine salt, removes carbon dioxide gas from the gas, and also removes dust from the gas by elution and absorption into the liquid phase. The gas with carbon dioxide and dust removed is discharged from the top of the absorption tower 2 as purified gas i; and the alcoholamine liquid (j) after absorbing carbon dioxide and dust is discharged from the bottom outlet of the absorption tower 2.

[0075] The alcoholamine liquid j after absorbing carbon dioxide and dust discharged from the bottom outlet of the absorption tower 2 is added to the liquid-solid separation device 3 (plate-frame filter) for liquid-solid separation. In the liquid-solid separation process, dust of 50 μm to 1 mm is precipitated and separated from the alcoholamine liquid under the action of gravity sedimentation, etc., while 80% of fine dust particles of ≯50 μm that are difficult to be removed under the action of natural forces are removed. The removed dust k is discharged from the sediment discharge outlet of the liquid-solid separation device 3 together with the precipitated dust, and the remaining 20% ​​≯50 μm still remains in the alcoholamine liquid.

[0076] The dust-free alcoholamine liquid m with 20% of dust impurities ≯50μm remaining enters the desorption regeneration tower 4 for desorption separation, and the generated carbamic acid organic amine salt is re-desorbed into carbon dioxide waste gas n and regenerated alcoholamine liquid (lean liquid, p) with low carbon dioxide content.

[0077] The generated carbon dioxide waste gas n is discharged from the top of the desorption regeneration tower 4 and then processed centrally; while the alcohol amine liquid p is returned to the absorption tower 2 for recycling, and fresh alcohol amine liquid f is added to supplement it when the alcohol amine liquid is insufficient. Since there is still a small amount of dust impurities ≯50μm, although the defoamer is added, there is still a certain amount of bubbles in the alcohol amine liquid, the foaming height is 12cm, and the defoaming time is 15s. Due to the presence of bubbles, the pressure of the absorption tower 2 rises to 15Kpa, the mechanical energy consumption is high, and the operating stability is reduced. The amount of carbon dioxide in the purified gas is 3%, the foaming degree is low, the defoaming is fast, and the decarbonization efficiency is high.

[0078] Example 2

[0079] In this embodiment, a new alcohol amine solution with a dust content of 50 mg / Nm 3 The decarbonization of blast furnace gas with a carbon dioxide content of 20% is described in detail as an example.

[0080] Among them, the dust content of 50μm~1mm and ≯50μm (≤50μm) is 30mg / Nm 3 and 20mg / Nm 3 .

[0081] Decarbonization process of blast furnace gas Figure 1 As shown, the details are as follows:

[0082] A certain amount of ethanolamine component a (MDEA) is added to the ethanolamine liquid preparation device 1, and a certain amount of water b is added and stirred to form an ethanolamine aqueous solution; a certain amount of activator c (PZ) is added to the ethanolamine aqueous solution, and stirred to form an ethanolamine aqueous solution with decarbonization activity; a certain amount of flocculant d (organic flocculant polyacrylamide) and defoamer e (lauric acid) are added to the ethanolamine aqueous solution, and stirred to form an ethanolamine liquid f that can eliminate the effect of dust on foaming. The components of the prepared ethanolamine liquid are shown in Table 2.

[0083] Table 2 Alcoholamine liquid composition

[0084] Components Alkylamine (MDEA) water Activator (PZ) Defoaming agent (lauric acid) Flocculant (polyacrylamide) content / % 20 65 5 5 5

[0085] The alcohol amine liquid (lean liquid, g) with low carbon dioxide content added from the upper part of the absorption tower 2 is fully mixed with the high dust gas h (blast furnace gas) added from the lower part of the tower, and absorbs the carbon dioxide component in the high dust gas to generate carbamic acid organic amine salt, removes carbon dioxide gas from the gas, and also removes dust from the gas by elution and absorption into the liquid phase. The gas with carbon dioxide and dust removed is discharged from the top of the absorption tower 2 as purified gas i; and the alcohol amine liquid j that absorbs carbon dioxide and dust is discharged from the bottom of the absorption tower 2.

[0086] The alcoholamine liquid j after absorbing carbon dioxide and dust discharged from the bottom of the absorption tower 2 is added to the liquid-solid separation device 3 (centrifugal filter) for liquid-solid separation. In the liquid-solid separation process, dust of 50 μm to 1 mm is deposited and separated from the alcoholamine liquid under the action of gravity sedimentation, etc., and dust of fine particles of ≯50 μm that is difficult to be removed by natural forces ≮95% (≥95%) is removed, and the removed dust k is discharged from the liquid-solid separation device 3, and the remaining ≯5%≯50 μm still remains in the alcoholamine liquid.

[0087] The dust-free alcoholamine liquid m with residual dust impurities of ≯5% or less and ≯50μm enters the desorption regeneration tower 4 for desorption separation, and the generated carbamic acid organic amine salt is re-desorbed into carbon dioxide waste gas n and regenerated alcoholamine liquid (lean liquid, p) with low carbon dioxide content.

[0088] The generated carbon dioxide waste gas n is discharged from the top of the desorption regeneration tower 4 and then processed centrally; while the alcohol amine liquid p is returned to the absorption tower 2 for recycling, and fresh alcohol amine liquid f is added to supplement when the alcohol amine liquid is insufficient. Since most of the dust impurities ≯50μm are removed, although the defoamer is added, there are still a certain amount of bubbles in the alcohol amine liquid, the foaming height is 3cm, and the defoaming time is 2s. Due to the existence of bubbles, the pressure of the absorption tower 2 rises to 10Kpa, the mechanical energy consumption is low, and the operation is stable. The carbon dioxide content in the purified gas is 0.5%, the foaming degree is low, the defoaming is fast, and the decarbonization efficiency is high.

[0089] Example 3

[0090] In this embodiment, a new alcohol amine solution with a dust content of 50 mg / Nm 3 The decarbonization of blast furnace gas with a carbon dioxide content of 20% is described in detail as an example.

[0091] Among them, the dust content of 50μm~1mm and ≯50μm (≤50μm) is 30mg / Nm 3 and 20mg / Nm 3 .

[0092] Decarbonization device and decarbonization process of blast furnace gas Figure 1 As shown, the details are as follows:

[0093] A certain amount of ethanolamine component a (MDEA) is added to the ethanolamine liquid preparation device 1, and a certain amount of water b is added and stirred to form an ethanolamine aqueous solution; a certain amount of activator c (PZ) is added to the ethanolamine aqueous solution, and stirred to form an ethanolamine aqueous solution with decarbonization activity; a certain amount of flocculant d (inorganic iron-based flocculant ferric chloride) and defoamer e (lauric acid) are added to the ethanolamine aqueous solution, and stirred to form an ethanolamine liquid f that can eliminate the effect of dust on foaming. The composition of the prepared ethanolamine liquid is shown in Table 3.

[0094] Table 3 Alcoholamine liquid composition

[0095] Components Alkylamine (MDEA) water Activator (PZ) Defoaming agent (lauric acid) Flocculant (ferric chloride) content / % 30 61 3 3 3

[0096] The alcoholamine liquid (lean liquid, g) with low carbon dioxide content added from the spray device (not shown) at the top of the absorption tower 2 is fully mixed with the high dust gas h (blast furnace gas) added from the bottom of the absorption tower, and absorbs the carbon dioxide component in the high dust gas to generate carbamic acid organic amine salt, removes carbon dioxide gas from the gas, and also removes dust from the gas by elution and absorption into the liquid phase. The gas with carbon dioxide and dust removed is discharged from the top of the absorption tower 2 as purified gas i; and the alcoholamine liquid (j) after absorbing carbon dioxide and dust is discharged from the bottom outlet of the absorption tower 2.

[0097] The alcoholamine liquid j after absorbing carbon dioxide and dust discharged from the bottom of the absorption tower 2 is added to the liquid-solid separation device 3 (centrifugal filter) for liquid-solid separation. In the liquid-solid separation process, dust of 50 μm to 1 mm is deposited and separated from the alcoholamine liquid under the action of gravity sedimentation, etc., and dust of fine particles of ≯50 μm that is difficult to be removed by natural forces ≮95% (≥95%) is removed, and the removed dust k is discharged from the liquid-solid separation device 3, and the remaining ≯5%≯50 μm still remains in the alcoholamine liquid.

[0098] The dust-free alcoholamine liquid m with residual dust impurities of ≯5% or less and ≯50μm enters the desorption regeneration tower 4 for desorption separation, and the generated carbamic acid organic amine salt is re-desorbed into carbon dioxide waste gas n and regenerated alcoholamine liquid (lean liquid, p) with low carbon dioxide content.

[0099] The generated carbon dioxide waste gas n is discharged from the top of the desorption regeneration tower 4 and then processed centrally; while the alcohol amine liquid p is returned to the absorption tower 2 for recycling, and fresh alcohol amine liquid f is added to supplement when the alcohol amine liquid is insufficient. Since most of the dust impurities ≯50μm are removed, although the defoamer is added, there are still a certain amount of bubbles in the alcohol amine liquid, the foaming height is 2cm, and the defoaming time is 2s. Due to the existence of bubbles, the pressure of the absorption tower 2 rises to 8Kpa, the mechanical energy consumption is low, and the operation is stable. The carbon dioxide content in the purified gas is 0.5%, the foaming degree is low, the defoaming is fast, and the decarbonization efficiency is high.

[0100] Example 4

[0101] In this embodiment, a new alcohol amine solution with a dust content of 50 mg / Nm 3 The decarbonization of blast furnace gas with a carbon dioxide content of 20% is described in detail as an example.

[0102] Among them, the dust content of 50μm~1mm and ≯50μm (≤50μm) is 30mg / Nm 3 and 20mg / Nm 3 .

[0103] Decarbonization device and decarbonization process of blast furnace gas Figure 1 As shown, the details are as follows:

[0104] A certain amount of ethanolamine component a (MDEA) is added to the ethanolamine liquid preparation device 1, and a certain amount of water b is added and stirred to form an ethanolamine aqueous solution; a certain amount of activator c (PZ) is added to the ethanolamine aqueous solution, and stirred to form an ethanolamine aqueous solution with decarbonization activity; a certain amount of flocculant d (inorganic iron-based flocculant ferric chloride) and defoamer e (lauric acid) are added to the ethanolamine aqueous solution, and stirred to form an ethanolamine liquid f that can eliminate the effect of dust on foaming. The composition of the prepared ethanolamine liquid is shown in Table 4.

[0105] Table 4 Alcoholamine liquid composition

[0106]

[0107]

[0108] The alcoholamine liquid (lean liquid, g) with low carbon dioxide content added from the spray device (not shown) at the top of the absorption tower 2 is fully mixed with the high dust gas h (blast furnace gas) added from the bottom of the absorption tower, and absorbs the carbon dioxide component in the high dust gas to generate carbamic acid organic amine salt, removes carbon dioxide gas from the gas, and also removes dust from the gas by elution and absorption into the liquid phase. The gas with carbon dioxide and dust removed is discharged from the top of the absorption tower 2 as purified gas i; and the alcoholamine liquid (j) after absorbing carbon dioxide and dust is discharged from the bottom outlet of the absorption tower 2.

[0109] The alcoholamine liquid j after absorbing carbon dioxide and dust discharged from the bottom of the absorption tower 2 is added to the liquid-solid separation device 3 (centrifugal filter) for liquid-solid separation. In the liquid-solid separation process, dust of 50 μm to 1 mm is deposited and separated from the alcoholamine liquid under the action of gravity sedimentation, etc., and dust of fine particles of ≯50 μm that is difficult to be removed by natural forces ≮95% (≥95%) is removed, and the removed dust k is discharged from the liquid-solid separation device 3, and the remaining ≯5%≯50 μm still remains in the alcoholamine liquid.

[0110] The dust-free alcoholamine liquid m with residual dust impurities of ≯5% or less and ≯50μm enters the desorption regeneration tower 4 for desorption separation, and the generated carbamic acid organic amine salt is re-desorbed into carbon dioxide waste gas n and regenerated alcoholamine liquid (lean liquid, p) with low carbon dioxide content.

[0111] The generated carbon dioxide waste gas n is discharged from the top of the desorption regeneration tower 4 and then processed centrally; while the alcohol amine liquid p is returned to the absorption tower 2 for recycling, and fresh alcohol amine liquid f is added to supplement it when the alcohol amine liquid is insufficient. Since most of the dust impurities ≯50μm are removed, although the defoamer is added, there are still a certain amount of bubbles in the alcohol amine liquid, the foaming height is 1cm, and the defoaming time is 1s. Due to the existence of bubbles, the pressure of the absorption tower 2 rises to 3Kpa, the mechanical energy consumption is low, and the operation is stable. The carbon dioxide content in the purified gas is 0.3%, the foaming degree is low, the defoaming is fast, and the decarbonization efficiency is high.

[0112] Example 5

[0113] In this embodiment, a new alcohol amine solution with a dust content of 50 mg / Nm 3 The decarbonization of blast furnace gas with a carbon dioxide content of 20% is described in detail as an example.

[0114] Among them, the dust content of 50μm~1mm and ≯50μm (≤50μm) is 30mg / Nm 3 and 20mg / Nm 3 .

[0115] Decarbonization device and decarbonization process of blast furnace gas Figure 1 As shown, the details are as follows:

[0116] A certain amount of alcoholamine component a (MDEA) is added to the alcoholamine liquid preparation device 1, and a certain amount of water b is added and stirred to form an alcoholamine aqueous solution; a certain amount of activator c (PZ) is added to the alcoholamine aqueous solution, and stirred to form an alcoholamine aqueous solution with decarbonization activity; a certain amount of flocculant d (ferric chloride) and defoamer e (silicon ether) are added to the alcoholamine aqueous solution, and stirred to form an alcoholamine liquid f that can eliminate the effect of dust on foaming. The composition of the prepared alcoholamine liquid is shown in Table 1.

[0117] Table 1 Alcoholamine liquid composition

[0118] Components Alkylamine (MDEA) water Activator (PZ) Defoaming agent (silicone ether) Flocculant (ferric chloride) content / % 50 43 1 1 5

[0119] The alcoholamine liquid (lean liquid, g) with low carbon dioxide content added from the spray device (not shown) at the top of the absorption tower 2 is fully mixed with the high dust gas h (blast furnace gas) added from the bottom of the absorption tower, and absorbs the carbon dioxide component in the high dust gas to generate carbamic acid organic amine salt, removes carbon dioxide gas from the gas, and also removes dust from the gas by elution and absorption into the liquid phase. The gas with carbon dioxide and dust removed is discharged from the top of the absorption tower 2 as purified gas i; and the alcoholamine liquid (j) after absorbing carbon dioxide and dust is discharged from the bottom outlet of the absorption tower 2.

[0120] The alcoholamine liquid j after absorbing carbon dioxide and dust discharged from the bottom of the absorption tower 2 is added to the liquid-solid separation device 3 (centrifugal filter) for liquid-solid separation. In the liquid-solid separation process, dust of 50 μm to 1 mm is deposited and separated from the alcoholamine liquid under the action of gravity sedimentation, etc., and dust of fine particles of ≯50 μm that is difficult to be removed by natural forces ≮95% (≥95%) is removed, and the removed dust k is discharged from the liquid-solid separation device 3, and the remaining ≯5%≯50 μm still remains in the alcoholamine liquid.

[0121] The dust-free alcoholamine liquid m with residual dust impurities of ≯5% or less and ≯50μm enters the desorption regeneration tower 4 for desorption separation, and the generated carbamic acid organic amine salt is re-desorbed into carbon dioxide waste gas n and regenerated alcoholamine liquid (lean liquid, p) with low carbon dioxide content.

[0122] The generated carbon dioxide waste gas n is discharged from the top of the desorption regeneration tower 4 and then processed centrally; while the alcohol amine liquid p is returned to the absorption tower 2 for recycling, and fresh alcohol amine liquid f is added to supplement when the alcohol amine liquid is insufficient. Since most of the dust impurities ≯50μm are removed, although the defoamer is added, there are still a certain amount of bubbles in the alcohol amine liquid, the foaming height is 3cm, and the defoaming time is 2s. Due to the existence of bubbles, the pressure of the absorption tower 2 rises to 10Kpa, the mechanical energy consumption is low, and the operation is stable. The carbon dioxide content in the purified gas is 0.5%, the foaming degree is low, the defoaming is fast, and the decarbonization efficiency is high.

[0123] Comparative Example 1

[0124] In this example, conventional alcohol amine solution is used to treat dust with a dust content of 50 mg / Nm 3 The decarbonization of blast furnace gas with a carbon dioxide content of 20% is described in detail as an example.

[0125] Among them, the dust content of 50μm~1mm and ≯50μm is 30mg / Nm 3 and 20mg / Nm 3 The components of the alcohol amine solution used are shown in Table 3.

[0126] Table 3 Alcoholamine liquid composition

[0127] Components Alkylamine (MDEA) water Activator (PZ) Defoaming agent (lauric acid) content / % 20 70 5 5

[0128] Decarbonization process of blast furnace gas Figure 2 As shown, the details are as follows:

[0129] The alcohol amine liquid (lean liquid, g) with low carbon dioxide content added from the upper part of the absorption tower 2 is fully mixed with the high dust gas h (blast furnace gas) added from the lower part of the tower, and absorbs the carbon dioxide component in the high dust gas to generate carbamic acid organic amine salt, removes carbon dioxide gas from the gas, and also removes dust from the gas by elution and absorption into the liquid phase. The gas with carbon dioxide and dust removed is discharged from the top of the absorption tower 2 as purified gas i; and the alcohol amine liquid j that absorbs carbon dioxide and dust is discharged from the bottom of the absorption tower 2.

[0130] The alcoholamine liquid j after absorbing carbon dioxide and dust discharged from the bottom of the absorption tower 2 is added to the liquid-solid separation device 3 (membrane filter) for liquid-solid separation. In the liquid-solid separation process, the dust k of 50 μm to 1 mm is precipitated and separated from the alcoholamine liquid under the action of gravity sedimentation, while the fine particle dust of ≯50 μm that is difficult to be separated under the action of natural forces cannot be separated and still remains in the alcoholamine liquid.

[0131] The dedusted alcoholamine liquid m from which dust of 50μm-1mm is removed but dust impurities ≯50μm still remain enters the desorption regeneration tower 4 for desorption separation, and the generated carbamic acid organic amine salt is re-desorbed into carbon dioxide waste gas n and regenerated alcoholamine liquid (lean liquid, p) with low carbon dioxide content.

[0132] The generated carbon dioxide waste gas n is discharged from the top of the desorption regeneration tower 4 and then processed centrally; while the alcohol amine liquid p is returned to the absorption tower 2 for recycling, and fresh alcohol amine liquid f is added to supplement it when the alcohol amine liquid is insufficient. Due to the presence of dust impurities ≯50μm, although the defoamer is added, there are still a large number of bubbles in the alcohol amine liquid, the foaming height is 16cm, and the defoaming time is 20s. The dust worsens the foaming phenomenon of the alcohol amine liquid. Due to the presence of a large number of bubbles, the pressure of the absorption tower 2 rises to 20Kpa, the mechanical energy consumption is high, and the operating stability is reduced. The amount of carbon dioxide in the purified gas is still 5%, and the decarbonization efficiency is low.

[0133] Compared with the comparative example, the foaming of the alcohol amine solution is basically suppressed in the embodiment, the pressure drop of the absorption tower 2 and the operability of the tower are greatly optimized, and the decarbonization effect is greatly improved.

[0134] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. An alcohol amine liquid for decarbonization of high-dust gas, characterized in that: include: Alkylamine, activator, flocculant, defoamer and water; The alcoholamine is selected from one or more of primary alcoholamine, secondary alcoholamine, tertiary alcoholamine or hindered alcoholamine; The activator is selected from one or more of piperazine, diethanolamine, diethylenetriamine, and diisopropanolamine; The flocculant is an inorganic flocculant, an organic flocculant, or a composite flocculant composed of an inorganic flocculant and an organic flocculant; The inorganic flocculant is selected from one or more of an iron-based flocculant, an aluminum-based flocculant, a poly-iron-based flocculant, a poly-aluminum-based flocculant, a poly-silicon-based flocculant and modified polymer flocculants, and the organic flocculant is a microbial flocculant or an organic polymer flocculant; The defoamer is a composite defoamer composed of one or more types of non-silicon type, silicone type, polyether type and polyether modified silicone type.

2. The alcoholamine solution according to claim 1, characterized in that The mass ratio of the alcoholamine in the alcoholamine solution is 10%-50%, preferably 20%, 30% or 40%; The mass ratio of the activator in the alcohol amine solution is 1%-10%, preferably 2%, 3%, 4% or 5%; The mass ratio of the flocculant in the alcohol amine solution is 1-10%, preferably 2%, 3%, 4% or 5%; The mass ratio of the defoamer in the alcohol amine solution is 1-10%, preferably 2%, 3%, 4% or 5%.

3. The alcoholamine solution according to claim 1, characterized in that The mass ratio of the alcoholamine in the alcoholamine solution is 20%, 30% or 40%; The mass ratio of the activator in the alcohol amine solution is 2%, 3%, 4% or 5%; The mass ratio of the flocculant in the alcohol amine solution is 2%, 3%, 4% or 5%; The mass ratio of the defoamer in the alcohol amine solution is 2%, 3%, 4% or 5%.

4. A device for decarbonizing high-dust gas, characterized in that: It includes an alcohol amine liquid preparation device, an absorption tower, a solid-liquid separation device, and a desorption regeneration tower; The alcohol amine liquid outlet is connected to the spray device in the absorption tower, the bottom outlet of the absorption tower is connected to the inlet of the solid-liquid separation device, the solid-liquid separation device outlet is connected to the upper inlet of the desorption regeneration tower, and the bottom outlet of the desorption regeneration tower is connected to the spray device in the absorption tower.

5. The device according to claim 4, characterized in that The top of the absorption tower is provided with a purified gas outlet, and the top of the desorption regeneration tower is provided with a CO2 waste gas outlet.

6. The device according to claim 4, characterized in that The absorption tower and the desorption regeneration tower are respectively provided with pressure monitoring devices.

7. The device according to claim 4, characterized in that The solid-liquid separation device includes one or a plurality of solid-liquid separation devices arranged in series.

8. The device according to claim 4, characterized in that The device is provided with a driving pump for driving the circulation of liquid in the device.

9. A method for decarbonizing high-dust gas according to the alcoholamine solution according to any one of claims 1 to 3 or the device according to any one of claims 4 to 8, characterized in that: include: S1: spraying the alcoholamine liquid in the alcoholamine preparation device into the absorption tower through the spraying device at the top of the absorption tower, and fully mixing the alcoholamine liquid with the high-dust gas added from the bottom of the absorption tower to obtain purified gas and carbamate organic amine salt, and the purified gas is discharged through the purified gas outlet at the top of the absorption tower; S2: The carbamate organic amine salt enters the solid-liquid separation device from the bottom outlet of the absorption tower, and the liquid obtained by the solid-liquid separation device enters the desorption regeneration tower from the upper inlet of the desorption regeneration tower for desorption and separation, and the generated carbamate organic amine salt is re-desorbed into carbon dioxide waste gas and regenerated alcohol amine liquid with low carbon dioxide content; S3: The regenerated alcohol amine solution is circulated to the spray device at the top of the absorption tower, and the above step S1 is repeated.

10. The method according to claim 9, characterized in that The preparation method of the alcoholamine solution comprises: adding an activator to an alcoholamine aqueous solution, stirring and mixing, adding a flocculant and a defoamer, and mixing evenly to obtain the alcoholamine solution; The mass ratio of the alcoholamine in the alcoholamine solution is 10%-50%, preferably 20%, 30% or 40%; The mass ratio of the activator in the alcohol amine solution is 1%-10%, preferably 2%, 3%, 4% or 5%; The mass ratio of the flocculant in the alcohol amine solution is 1-10%, preferably 2%, 3%, 4% or 5%; The mass ratio of the defoamer in the alcohol amine solution is 1-10%, preferably 2%, 3%, 4% or 5%.

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