Desulfurizing agent for removing sulfur-containing gas in flue gas and preparation method thereof

Abstract

The invention discloses a desulfurizing agent for removing sulfur-containing gas in flue gas and a preparation method of the desulfurizing agent. The desulfurizing agent comprises 0.1-10 wt% of a main absorption component, 0.1-1 wt% of an amino acid additive, 3-20 wt% of an inhibitor, 75-95 wt% of water and 0.01-0.1 wt% of an antioxidant. The desulfurizer provided by the invention solves the problems that the desulfurizer in the prior art is not high in desulfurization selectivity and can absorb CO2 during desulfurization.

Description

Technical Field

[0001] This invention belongs to the field of flue gas treatment technology, specifically relating to a desulfurizing agent for removing sulfur-containing gases from flue gas and its preparation method. Background Technology

[0002] my country's chemical industry has experienced rapid development in recent decades. Simultaneously, the expansion of industrial production has brought about numerous environmental governance challenges. Flue gas treatment is a major area of ​​environmental protection and is receiving increasing attention. SO2 is one of the main pollutants in industrial air and a primary cause of acid rain. SO2 emissions into the atmosphere cause varying degrees of harm to the natural ecological environment, human health, industrial and agricultural production, buildings, and materials. For a typical oil refinery, SO2 emissions... x SO₂ emissions account for approximately 6-7 wt% of total pollutant emissions. In various stages of crude oil processing, SO₂ in FCC regeneration flue gas... x The largest share of emissions, accounting for the largest proportion of refinery SO2 emissions. x Total emissions account for 70-80 wt%. Therefore, how to reduce SO₂ in FCC regeneration flue gas is crucial. x Emissions have become a focal point of discussion.

[0003] Fluid catalytic cracking (FCC) is a crucial method for refining heavy oil into lighter grades. The FCC process generates significant amounts of flue gas pollutants, primarily from sulfides (SO2 and SO3 gases), nitrogen oxides (NO and NO2 gases) produced during the regeneration of deactivated catalysts, and large particulate matter and dust generated by catalyst wear. Statistics show that SO2 in FCC regeneration flue gas... x The average content is around 800 ppm. Increased sulfur content in crude oil leads to higher SO2 concentrations in FCC regeneration flue gas. x The content also increases accordingly. Besides SO x NO x In addition to pollutants such as SO2, FCC flue gas also contains 8-10 wt% CO2. CO2 in the flue gas can also be absorbed by desulfurizing agents, which will increase the consumption of desulfurizing agents and desulfurization costs. On the other hand, current desulfurizing agents are not very selective for SO2, and CO2 will be lost while removing SO2, which will affect the operating costs of subsequent CO2 capture processes.

[0004] CN101274204A provides a composite desulfurizing agent with an organic cation and an inorganic anion as the main absorbent and an alkyl alcohol amine with steric hindrance as the activator, exhibiting a certain selectivity for SO2. This technology requires the use of activators, corrosion inhibitors, and other agents to form a composite desulfurization absorbent solution. Its overall sulfur absorption capacity is generally low, it is highly corrosive to equipment, and the absorption rate of this composite desulfurizing agent gradually decreases.

[0005] CN113332849A provides a method for flue gas SDA desulfurization and dust removal, which can be applied when the SO2 concentration is less than 300 mg / m³. 3 Under certain conditions, this technology achieves an SO2 removal efficiency of over 90% and also has a dust removal function. However, it uses a calcium-based desulfurizing agent, which has low selectivity for SO2 and easily results in CO2 loss while removing SO2.

[0006] CN110124449A discloses a composite amine absorbent for absorbing SO2 and its preparation method, which features strong selectivity for SO2. This composite amine absorbent is only suitable for flue gas containing no oxygen or very low oxygen content, because it contains hydroxyethyldiamine, and therefore undergoes degradation in oxygen-rich gas. Summary of the Invention

[0007] The purpose of this invention is to provide a desulfurizing agent for removing sulfur-containing gases from flue gas, so as to solve the problems of low selectivity of desulfurizing agents in the prior art and the absorption of CO2 during desulfurization.

[0008] The present invention also aims to provide a method for preparing a desulfurizing agent for removing sulfur-containing gases from flue gas.

[0009] To achieve the above objectives, the present invention provides a desulfurizing agent for removing sulfur-containing gases from flue gas, comprising 0.1-10 wt% of a main absorbent component, 0.1-1 wt% of an amino acid auxiliary agent, 3-20 wt% of an inhibitor, 75-95 wt% of water, and 0.01-0.1 wt% of an antioxidant.

[0010] The desulfurizing agent for removing sulfur-containing gases from flue gas according to the present invention comprises one or more of magnesium calcium carbonate, calcium fluorophosphate, manganese oxide, and manganese tetroxide as the main absorbent component.

[0011] The desulfurizing agent for removing sulfur-containing gases from flue gas according to the present invention comprises one or more of glycine, L-alanine, DL-alanine, β-alanine, proline, and arginine.

[0012] The desulfurizing agent for removing sulfur-containing gases from flue gas according to the present invention uses sodium bicarbonate as the inhibitor.

[0013] The desulfurizing agent for removing sulfur-containing gases from flue gas according to the present invention includes an antioxidant comprising one or more of polyols, polyphenols, and organometallic complexing agents.

[0014] The desulfurizing agent for removing sulfur-containing gases from flue gas according to the present invention comprises: the polyphenol being tert-butylhydroquinone and / or hydroquinone; the polyol being ethylene glycol and / or glycerol; and the organometallic complexing agent being disodium ethylenediaminetetraacetate.

[0015] The desulfurizing agent for removing sulfur-containing gases from flue gas according to the present invention has magnesium calcium carbonate as the main absorbent component.

[0016] The desulfurizing agent for removing sulfur-containing gases from flue gas according to the present invention uses β-alanine as the amino acid auxiliary agent.

[0017] The desulfurizing agent for removing sulfur-containing gases from flue gas according to the present invention comprises 0.2-9 wt% of main absorbent component, 0.2-0.8 wt% of amino acid auxiliaries, 5-15 wt% of inhibitor, 80-90 wt% of water, and 0.03-0.08 wt% of antioxidant.

[0018] To achieve the above objectives, the present invention also provides a method for preparing the desulfurizing agent for removing sulfur-containing gases from flue gas, wherein the main absorbent component, amino acid adjuvant, inhibitor, water and antioxidant are mixed evenly to obtain the desulfurizing agent.

[0019] Beneficial effects of this invention:

[0020] Compared to traditional desulfurization processes, this desulfurizing agent uses a composite desulfurizer with magnesium calcium carbonate, calcium fluorophosphate, and manganese oxide as the main absorbent components, improving the desulfurization efficiency for low-concentration sulfur-containing gases. It also incorporates amino acid additives, enhancing the selectivity of SO2 absorption while maintaining the absorption rate and avoiding significant desulfurizer loss caused by CO2 absorption. Furthermore, the addition of inhibitors and antioxidants makes the resulting desulfurizer less volatile and less corrosive to equipment. The composite desulfurizer used in this process has widely available raw materials, is readily available for preparation, and is easy to operate. Detailed Implementation

[0021] The present invention will now be described in detail through embodiments. It should be noted that the following embodiments are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.

[0022] Example 1

[0023] This embodiment is used to illustrate the flue gas desulfurizer provided by the present invention.

[0024] 1. Simulated FCC flue gas composition (volume): SO2: 732 mg / Nm³ 3 CO2: 2896 mg / Nm 3 ; O2: 10.8%; H2O: 8.2%, CO: 1.05%; NO x 0.5%, with an organic sulfur compound (COS) content of 70 mg / Nm³. 3 The rest is nitrogen.

[0025] 2. Add 100g magnesium calcium carbonate, 7.5g β-alanine, 230g sodium bicarbonate and 1g hydroquinone to 800ml distilled water according to the specified ratio, stir well, and measure to 1500g with distilled water to obtain the flue gas desulfurizer of the present invention.

[0026] 3. Heat 1500g of desulfurizing agent to 60℃, and use a peristaltic pump to send the desulfurizing agent from the top of the spray tower into the atomizer of the spray tower. Introduce the simulated flue gas described in step 1 into the flue gas pipe from the top of the desulfurization tower. The gas contacts the atomized droplets from the top atomizer, with a liquid-to-gas ratio of 0.35kg / Nm³. 3 The purified gas is dried by a drying device at the bottom of the absorption tower before being discharged. The composition of the discharged gas was detected by a flue gas analyzer, and the results are shown in Table 1.

[0027] Example 2

[0028] This embodiment is used to illustrate the flue gas desulfurizer provided by the present invention.

[0029] 1. Simulated FCC flue gas composition (volume): SO2: 716 mg / Nm³ 3 CO2: 2931 mg / Nm 3 ; O2: 10.8%; H2O: 8.2%, CO: 1.05%; NO x 0.5%, with an organic sulfur compound (COS) content of 70 mg / Nm³. 3 The rest is nitrogen.

[0030] 2. Add 50g magnesium calcium carbonate, 7.5g arginine, 280g sodium bicarbonate and 1g disodium ethylenediaminetetraacetate to 800ml of distilled water according to the specified ratio, stir well, and measure to 1500g with distilled water to obtain the flue gas desulfurizing agent of the present invention.

[0031] 3. Heat 1500g of desulfurizing agent to 60℃, and use a peristaltic pump to send the desulfurizing agent from the top of the spray tower into the atomizer of the spray tower. Introduce the simulated flue gas described in step 1 into the flue gas pipe from the top of the desulfurization tower. The gas contacts the atomized droplets from the top atomizer, with a liquid-to-gas ratio of 0.35kg / Nm³. 3 The purified gas is dried by a drying device at the bottom of the absorption tower before being discharged. The composition of the discharged gas was detected by a flue gas analyzer, and the results are shown in Table 1.

[0032] Example 3

[0033] This embodiment is used to illustrate the flue gas desulfurizer provided by the present invention.

[0034] 1. Simulated FCC flue gas composition (volume): SO2: 526 mg / Nm³ 3 CO2: 2153 mg / Nm3 ; O2: 11.8%; H2O: 9.6%, CO: 1.05%; NO x 0.5%, with an organic sulfur compound (COS) content of 70 mg / Nm³. 3 The rest is nitrogen.

[0035] 2. Add 80g magnesium calcium carbonate, 6g β-alanine, 200g sodium bicarbonate and 0.6g p-tert-butylhydroquinone to 600ml of distilled water according to the specified ratio, and dilute to 1000g with distilled water. Stir well to obtain the flue gas desulfurizer of the present invention.

[0036] 3. Heat 1000g of desulfurizing agent to 55℃, and use a peristaltic pump to send the desulfurizing agent from the top of the spray tower into the atomizer of the spray tower. The simulated flue gas described in step 1 is then introduced into the flue gas pipe from the top of the desulfurization tower, where the gas contacts the atomized droplets from the top atomizer. The liquid-to-gas ratio is 0.3kg / Nm³. 3 The purified gas is dried by a drying device at the bottom of the absorption tower before being discharged. The composition of the discharged gas was detected by a flue gas analyzer, and the results are shown in Table 1.

[0037] Example 4

[0038] This embodiment is used to illustrate the flue gas desulfurizer provided by the present invention.

[0039] 1. Simulated FCC flue gas composition (volume): SO2: 531 mg / Nm³ 3 CO2: 2216 mg / Nm 3 ; O2: 10.4%; H2O: 9.3%, CO: 1.05%; NO x 0.5%, with an organic sulfur compound (COS) content of 70 mg / Nm³. 3 The rest is nitrogen.

[0040] 2. Add 50g magnesium calcium carbonate, 4.5g β-alanine, 150g sodium bicarbonate and 0.6g ethylene glycol to 600ml distilled water according to the specified ratio, stir well, and measure to 1000g with distilled water to obtain the flue gas desulfurizing agent of the present invention.

[0041] 3. Heat 1000g of desulfurizing agent to 55℃, and use a peristaltic pump to send the desulfurizing agent from the top of the spray tower into the atomizer of the spray tower. The simulated flue gas described in step 1 is then introduced into the flue gas pipe from the top of the desulfurization tower, where the gas contacts the atomized droplets from the top atomizer. The liquid-to-gas ratio is 0.3kg / Nm³. 3 The purified gas is dried by a drying device at the bottom of the absorption tower before being discharged. The composition of the discharged gas was detected by a flue gas analyzer, and the results are shown in Table 1.

[0042] Example 5

[0043] This embodiment is used to illustrate the flue gas desulfurizer provided by the present invention.

[0044] 1. Simulated FCC flue gas composition (volume): SO2: 156 mg / Nm³ 3 CO2: 1115 mg / Nm 3 ; O2: 13.7%; H2O: 12.2%, CO: 1.05%; NO x 0.5%, with an organic sulfur compound (COS) content of 70 mg / Nm³. 3 The rest is nitrogen.

[0045] 2. Add 25g manganese oxide, 1.5g L-alanine, 0.3g ethylene glycol and 70g sodium bicarbonate to 100ml distilled water according to the specified ratio, stir well, and measure to 500g with distilled water to obtain the flue gas desulfurizing agent of the present invention.

[0046] 3. Heat 500g of desulfurizing agent to 50℃, and use a peristaltic pump to send the desulfurizing agent from the top of the spray tower into the atomizer of the spray tower. Introduce the simulated flue gas described in step 1 into the flue gas pipe from the top of the desulfurization tower. The gas contacts the atomized droplets from the atomizer at the top, with a liquid-to-gas ratio of 0.2kg / Nm³. 3 The purified gas is dried by a drying device at the bottom of the absorption tower before being discharged. The composition of the discharged gas was detected by a flue gas analyzer, and the results are shown in Table 1.

[0047] Example 6

[0048] This embodiment is used to illustrate the flue gas desulfurizer provided by the present invention.

[0049] 1. Simulated FCC flue gas composition (volume): SO2: 156 mg / Nm³ 3 CO2: 1115 mg / Nm 3 ; O2: 13.7%; H2O: 12.2%, CO: 1.05%; NO x 0.5%, with an organic sulfur compound (COS) content of 70 mg / Nm³. 3 The rest is nitrogen.

[0050] 2. Add 45g of manganese oxide, 4.5g of L-alanine, 0.4g of ethylene glycol and 80g of sodium bicarbonate to 100ml of distilled water according to the specified ratio, stir well, and measure to 500g with distilled water to obtain the flue gas desulfurizing agent of the present invention.

[0051] 3. Heat 500g of desulfurizing agent to 50℃, and use a peristaltic pump to send the desulfurizing agent from the top of the spray tower into the atomizer of the spray tower. Introduce the simulated flue gas described in step 1 into the flue gas pipe from the top of the desulfurization tower. The gas contacts the atomized droplets from the atomizer at the top, with a liquid-to-gas ratio of 0.2kg / Nm³. 3 The purified gas is dried by a drying device at the bottom of the absorption tower before being discharged. The composition of the discharged gas is detected using a flue gas analyzer.

[0052] Example 7

[0053] This embodiment is used to illustrate the flue gas desulfurizer provided by the present invention.

[0054] 1. Simulated FCC flue gas composition (volume): SO2: 156 mg / Nm³ 3 CO2: 1115 mg / Nm 3 ; O2: 13.7%; H2O: 12.2%, CO: 1.05%; NO x 0.5%, with an organic sulfur compound (COS) content of 70 mg / Nm³. 3 The rest is nitrogen.

[0055] 2. Add 1g of calcium fluorophosphate, 1g of L-alanine, 0.1g of glycerol and 25g of sodium bicarbonate to 100ml of distilled water according to the specified ratio, stir well, and measure to 500g with distilled water to obtain the flue gas desulfurizing agent of the present invention.

[0056] 3. Heat 500g of desulfurizing agent to 50℃, and use a peristaltic pump to send the desulfurizing agent from the top of the spray tower into the atomizer of the spray tower. Introduce the simulated flue gas described in step 1 into the flue gas pipe from the top of the desulfurization tower. The gas contacts the atomized droplets from the atomizer at the top, with a liquid-to-gas ratio of 0.2kg / Nm³. 3 The purified gas is dried by a drying device at the bottom of the absorption tower before being discharged. The composition of the discharged gas is detected using a flue gas analyzer.

[0057] Comparative Example 1

[0058] This comparative example is used to illustrate the flue gas desulfurizer provided by the present invention.

[0059] 1. Simulated FCC flue gas composition (volume): SO2: 732 mg / Nm³ 3 CO2: 2896 mg / Nm 3 ; O2: 10.8%; H2O: 8.2%, CO: 1.05%; NO x 0.5%, with an organic sulfur compound (COS) content of 70 mg / Nm³. 3 The rest is nitrogen.

[0060] 2. The desulfurizing agent is a traditional calcium-based desulfurizing agent, consisting of calcium hydroxide and water, with a Ca(OH)2 content of 20wt% and the remainder being water.

[0061] 3. Heat 1500g of desulfurizing agent to 60℃, and use a peristaltic pump to send the desulfurizing agent from the top of the spray tower into the atomizer of the spray tower. Introduce the simulated flue gas described in step 1 into the flue gas pipe from the top of the desulfurization tower. The gas contacts the atomized droplets from the top atomizer, with a liquid-to-gas ratio of 0.35kg / Nm³. 3 The purified gas is dried by a drying device at the bottom of the absorption tower before being discharged. The composition of the discharged gas was detected by a flue gas analyzer, and the results are shown in Table 1.

[0062] Comparative Example 2

[0063] This comparative example is used to illustrate the flue gas desulfurizer provided by the present invention.

[0064] 1. Simulated FCC flue gas composition (volume): SO2: 156 mg / Nm³ 3 CO2: 1115 mg / Nm 3 ; O2: 13.7%; H2O: 12.2%, CO: 1.05%; NO x 0.5%, with an organic sulfur compound (COS) content of 70 mg / Nm³. 3 The rest is nitrogen.

[0065] 2. The desulfurizing agent is a sodium-based desulfurizing agent, consisting of sodium carbonate and water, with a Na2CO3 content of 20wt% and the remainder being water.

[0066] 3. Heat 500g of desulfurizing agent to 50℃, and use a peristaltic pump to send the desulfurizing agent from the top of the spray tower into the atomizer of the spray tower. Introduce the simulated flue gas described in step 1 into the flue gas pipe from the top of the desulfurization tower. The gas contacts the atomized droplets from the atomizer at the top, with a liquid-to-gas ratio of 0.2kg / Nm³. 3 The purified gas is dried by a drying device at the bottom of the absorption tower before being discharged. The composition of the discharged gas was detected by a flue gas analyzer, and the results are shown in Table 1.

[0067] Comparative Example 3

[0068] 1. Simulated FCC flue gas composition (volume): SO2: 732 mg / Nm³ 3 CO2: 2896 mg / Nm 3 ; O2: 10.8%; H2O: 8.2%, CO: 1.05%; NO x 0.5%, with an organic sulfur compound (COS) content of 70 mg / Nm³. 3 The rest is nitrogen.

[0069] 2. Add 100g magnesium calcium carbonate, 230g sodium bicarbonate and 1g hydroquinone to 800ml distilled water according to the specified ratio, stir well, and measure to 1500g with distilled water to obtain the flue gas desulfurizer of the present invention.

[0070] 3. Heat 1500g of desulfurizing agent to 60℃, and use a peristaltic pump to send the desulfurizing agent from the top of the spray tower into the atomizer of the spray tower. Introduce the simulated flue gas described in step 1 into the flue gas pipe from the top of the desulfurization tower. The gas contacts the atomized droplets from the top atomizer, with a liquid-to-gas ratio of 0.35kg / Nm³. 3 The purified gas is dried by a drying device at the bottom of the absorption tower before being discharged. The composition of the discharged gas was detected by a flue gas analyzer, and the results are shown in Table 1.

[0071] Comparative Example 4

[0072] 1. Simulated FCC flue gas composition (volume): SO2: 732 mg / Nm³ 3 CO2: 2896 mg / Nm 3 ; O2: 10.8%; H2O: 8.2%, CO: 1.05%; NO x 0.5%, with an organic sulfur compound (COS) content of 70 mg / Nm³. 3 The rest is nitrogen.

[0073] 2. Add 100g NaCO3, 7.5g β-alanine, 230g sodium bicarbonate and 1g hydroquinone to 800ml distilled water according to the specified ratio, stir well, and measure to 1500g with distilled water to obtain the flue gas desulfurizing agent of the present invention.

[0074] 3. Heat 1500g of desulfurizing agent to 60℃, and use a peristaltic pump to send the desulfurizing agent from the top of the spray tower into the atomizer of the spray tower. Introduce the simulated flue gas described in step 1 into the flue gas pipe from the top of the desulfurization tower. The gas contacts the atomized droplets from the top atomizer, with a liquid-to-gas ratio of 0.35kg / Nm³. 3 The purified gas is dried by a drying device at the bottom of the absorption tower before being discharged. The composition of the discharged gas was detected by a flue gas analyzer, and the results are shown in Table 1.

[0075] Table 1

[0076]

[0077] As can be seen from the results in Table 1, Examples 1-7 generally showed better desulfurization effects than the comparative examples. Comparative Examples 1 and 2 used conventional desulfurizing agents, and their desulfurization effects were not as good as those of the corresponding examples when dealing with low-concentration flue gas. Furthermore, the CO2 loss after desulfurization was relatively high. Comparative Example 3 differed from Example 1 in that it used an amino acid adjuvant. Without the amino acid adjuvant, the desulfurization efficiency increased slightly, but not as significantly as with the adjuvant. The CO2 loss was also much higher than in Example 1, and it did not show good selectivity for SO2. Comparative Example 4 differed from Example 1 in that it used the main absorbent. While the desulfurization effect was also poor, the CO2 loss rate decreased significantly, indicating that the adjuvant improved the selectivity for SO2 in the flue gas. Therefore, the desulfurizing agent provided by this invention can be used to remove SO2 from FCC flue gas. This desulfurization solution has the advantages of high selectivity and high desulfurization efficiency.

[0078] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A desulfurizer for removing sulfur-containing gas from flue gas, characterized in that: The invention comprises 0.1-10 wt% of main absorption component, 0.1-1 wt% of amino acid auxiliary agent, 3-20 wt% of inhibitor, 75-95 wt% of water and 0.01-0.1 wt% of antioxidant.

2. The desulfurizing agent for removing sulfur-containing gas in flue gas according to claim 1, characterized in that: The amino acid auxiliary agent is one or more of glycine, L-alanine, DL-alanine, β-alanine, proline and arginine.

3. The desulfurizing agent for removing sulfur-containing gas in flue gas according to claim 1, characterized in that: The main absorption component is one or more of calcium magnesium carbonate, calcium fluorophosphate, manganese oxide and trimanganese tetraoxide.

4. The desulfurizing agent for removing sulfur-containing gas in flue gas according to claim 1, characterized in that: The inhibitor is sodium bicarbonate.

5. The desulfurizing agent for removing sulfur-containing gas in flue gas according to claim 1, characterized in that: The antioxidant includes one or more of polyols, polyphenols and metal organic complexing agents.

6. The desulfurizing agent for removing sulfur-containing gas in flue gas according to claim 5, characterized in that: The polyphenol is tert-butylhydroquinone and / or hydroquinone; the polyol is ethylene glycol and / or glycerol; and the metal organic complexing agent is disodium ethylenediaminetetraacetate.

7. The desulfurizing agent for removing sulfur-containing gas in flue gas according to claim 1, characterized in that: The main absorption component is magnesium calcium carbonate.

8. The desulfurizing agent for removing sulfur-containing gas in flue gas according to claim 1, characterized in that: The amino acid auxiliary agent is β-alanine.

9. The desulfurizing agent for removing sulfur-containing gas from flue gas according to claim 1, characterized in that: The invention comprises 0.2-9 wt% of main absorption component, 0.2-0.8 wt% of amino acid auxiliary agent, 5-15 wt% of inhibitor, 80-90 wt% of water and 0.03-0.08 wt% of antioxidant.

10. The method for preparing a desulfurizing agent for removing sulfur-containing gas from flue gas according to any one of claims 1 to 9, characterized in that: The main absorption component, amino acid auxiliary agent, inhibitor, water and antioxidant are uniformly mixed to obtain the desulfurizing agent.

Images