CN115945203A - Preparation method and application of a highly acid-resistant blast furnace gas organic sulfur hydrolysis catalyst - Google Patents

Abstract

The invention relates to a preparation method and application of a high-acid-gas-resistance blast furnace gas organic sulfur hydrolysis catalyst. The preparation method comprises the following steps: in the form of spherical gamma-Al ₂ O ₃ The carrier is first soaked with AgNO in 0.1-3 wt% in the same amount ₃ The solution is placed in the shade for drying, and then is soaked by 0.01 to 0.05mol/L dilute hydrochloric acid for treatment, and the high acid gas resistant blast furnace gas organic sulfur hydrolysis catalyst is obtained after post-treatment. The catalystHas obvious acid gas resistance, high hydrolysis activity of the organic sulfur COS of the blast furnace gas, is not easy to inactivate, and solves the problem that the acid gas in the blast furnace gas is easy to rapidly inactivate an organic sulfur hydrolysis catalyst.

Description

A method for preparing a blast furnace gas organic sulfur hydrolysis catalyst with high resistance to acidic gases and its application

Technical Field

The invention belongs to the technical field of blast furnace gas fine desulfurization, and relates to a preparation method and application of a blast furnace gas organic sulfur hydrolysis catalyst with high acid gas resistance.

Background Art

Blast furnace gas is a combustible gas produced as a byproduct of ironmaking in the blast furnace, the core equipment of the steel industry. It usually contains major gas components such as CO 20-30%, CO ₂ 10-20%, H ₂ 1-4%, and N ₂ 50-60%. At the same time, blast furnace gas also contains sulfides of 200-300 mg/m ³ , of which more than 90% is organic sulfur, mainly COS, and sometimes a small amount of CS _2. At present, China's steel industry produces nearly 1 trillion cubic meters of blast furnace gas per year. After dust removal and TRT residual pressure power generation, this gas is sent to blast furnace hot blast furnaces, steel rolling heating furnaces, gas boilers, etc. as fuel. Because the sulfide component in the gas is more than 200 mg/m ³ , the SO ₂ in the flue gas after combustion cannot meet the requirements of ultra-low emissions.

To promote the implementation of ultra-low emissions in the steel industry, it is necessary to control the blast furnace gas desulfurization at the source, which can ensure ultra-low _SO2 emissions for downstream users and avoid the construction of scattered end-of-pipe treatment facilities. It is of great significance to promote ultra-low emission transformation of the entire process of the steel industry and promote green development of the steel industry.

The key to fine desulfurization of blast furnace gas is the removal of organic sulfur COS. According to the characteristics of large gas volume, low hydrogen, and medium and low temperature of blast furnace gas, it is usually hydrolyzed into inorganic sulfur H ₂ S before removal. Organic sulfur COS hydrolysis catalysts are relatively mature both at home and abroad, and are currently widely used in petrochemical and coal chemical industries. Foreign countries began to study COS hydrolysis catalysts in the 1960s, and the Cr ₂ O ₃ /Al ₂ O ₃ series G41-P hydrolysis catalyst, Pt/Al ₂ O ₃ series C53-2-01 hydrolysis catalyst, and alumina-based R10-15 hydrolysis catalyst of BASF in Germany appeared. It is generally recommended to use it at high temperatures of 200 to 400 °C. The Chinese invention patent CN1069673A applied for by the Hubei Institute of Chemistry in 1992 first disclosed a room-temperature organic _sulfur hydrolysis catalyst loaded with _K2CO3 by the γ- _Al2O3 impregnation _method . Since then, the catalyst has been widely used in chemical, fertilizer and other industries, and was named T504 organic sulfur hydrolysis catalyst by the Fertilizer Catalyst Center of the former Ministry of Chemical Industry. Since then, Nanhua Catalyst CN1134312A disclosed a _TiO2- modified γ- _{Al2O3 -} based organic sulfur hydrolysis catalyst, and Taiyuan University of Technology CN1189394A disclosed a _K2CO3 /γ- _Al2O3 organic _sulfur hydrolysis catalyst with added _Mo2O3 . The focus of relevant patents and public documents is mainly on the modification of the carrier or the addition of transition metal additives, but _it is generally believed that the reaction mechanism _of COS hydrolysis catalyst should be catalysis by weakly alkaline active centers.

Blast furnace gas usually also contains 0.0001-0.01% by volume of _acidic gases such as HCl and HCN. These components can easily cause the rapid deactivation of traditional _K2CO3 /γ- _{Al2O3 -} based organic sulfur hydrolysis catalysts, which poses a huge challenge to the long-term stable operation of organic sulfur hydrolysis catalysts in blast furnace gas. In recent years, blast furnace gas organic sulfur hydrolysis catalysts have begun to receive attention. CN112439409A discloses a hydrolysis catalyst for blast furnace gas desulfurization and a preparation method thereof, wherein mesoporous alumina is used as a carrier, the active component is an alkali metal or alkaline earth metal nitrate, and the auxiliary agent is a transition metal Mn, Co, Zn, Mo nitrate. After high-temperature calcination, the above nitrate may decompose into oxides, and the catalyst system is essentially a metal oxide.

Whether it is the conventional organic sulfur hydrolysis catalyst that has been widely used in the chemical industry or the newly developed organic sulfur hydrolysis catalyst for blast furnace gas, its catalytic system is still mainly weakly alkaline carbonate or transition metal oxide supported by alumina. When these catalysts are used in blast furnace gas containing acidic gases such as HCl and HCN, the active center is easily destroyed, causing the catalyst to deactivate quickly. There is also a traditional alkaline hydrolysis catalyst protected by adding a dechlorination protective agent, but because of the high content of hydrogen chloride, it is easy to penetrate and cause the active center of the hydrolysis catalyst to undergo an acid-base reaction and become inactivated. Therefore, in most blast furnace gas fine desulfurization industrial tests or trial devices, the hydrolysis catalyst life is only a short 1 to 3 months, which is far from meeting the requirements of industrial application.

Therefore, it is urgent to find an organic sulfur hydrolysis catalyst for blast furnace gas with high acid resistance and good stability.

Summary of the invention

The purpose of the present invention is to provide a method for preparing an organic sulfur hydrolysis catalyst for blast furnace gas with high acid gas resistance and its application in view of the deficiencies of the prior art. The catalyst has significant acid gas resistance, high activity for hydrolyzing organic sulfur COS in blast furnace gas, and is not easy to deactivate, thus solving the problem that acid gas in blast furnace gas easily causes rapid deactivation of the organic sulfur hydrolysis catalyst.

In order to achieve the above object, the technical solution adopted by the present invention is:

Provided is a method for preparing a blast furnace gas organic sulfur hydrolysis catalyst with high acid gas resistance, comprising the following steps:

The spherical γ-Al ₂ O ₃ carrier is firstly impregnated with an equal amount of 0.1-3% AgNO ₃ solution by weight, placed in the shade for drying, and then soaked in 0.01-0.05 mol/L dilute hydrochloric acid. After post-treatment, a blast furnace gas organic sulfur hydrolysis catalyst with high acid gas resistance is obtained.

According to the above scheme, the particle size of the spherical γ-Al ₂ O ₃ carrier is 4-6 mm, and the specific surface area is 150-250 m ² /g.

According to the above scheme, the mass percentage of the AgNO ₃ solution is preferably 0.1-1%.

According to the above plan, the time for drying in the shade is 4 to 24 hours.

According to the above scheme, the dilute hydrochloric acid immersion treatment time is 1 to 4 hours.

According to the above scheme, the post-treatment is as follows: the catalyst is rinsed with deionized water to remove residual hydrochloric acid, and then dried at 120-150°C.

Provided is a blast furnace gas organic sulfur hydrolysis catalyst with high acid gas resistance and its application in blast furnace gas organic sulfur hydrolysis; wherein the blast furnace organic sulfur hydrolysis _catalyst with high acid gas resistance uses spherical γ- _Al2O3 as a carrier, loaded with AgCl, and the loading amount of silver chloride is 0.08-2.6wt%.

According to the above scheme, the loading amount of silver chloride is preferably 0.08%-0.8%.

According to the above scheme, the blast furnace gas organic sulfur hydrolysis catalyst with high acid gas resistance is prepared by the above preparation method.

According to the above scheme, the blast furnace gas contains acidic gas, preferably, the acidic gas is at least one of HCl and HCN, and the content of the acidic gas is 0.0001-0.01%.

According to the above scheme, the catalytic hydrolysis temperature of the organic sulfur hydrolysis catalyst is 80-150°C.

The beneficial effects of the present invention are:

1. The present invention provides a method for preparing a blast furnace gas organic sulfur hydrolysis _catalyst with high resistance to acidic gases. The method adopts γ- _Al2O3 with excellent pores and specific surface to load silver nitrate, and uses dilute hydrochloric acid of appropriate concentration for post-treatment to make the active metallic silver on the catalyst exist in a stable form of silver chloride. The catalyst thus obtained has outstanding resistance to acidic gases such as HCl, HCN, and _CO2 , and solves the problem of poisoning of the alkaline active center of the organic sulfur hydrolysis catalyst by related acidic gas poisons in blast furnace gas. The catalyst is simple to prepare and does not require calcination treatment, so it has broad application prospects.

2. The catalyst obtained by the present invention is used to catalyze the hydrolysis of organic sulfur in blast furnace gas. The COS conversion rate can reach 99.9%. It has excellent acid resistance and stability. The pilot life has exceeded half a year and has important industrial application value. The blast furnace gas treated by the present invention does not need to set up a guard bed. After dust removal, the blast furnace gas directly enters the acid-resistant hydrolysis tower, and then passes through TRT power generation and uses dry iron oxide to break down hydrogen sulfide, so that hydrogen sulfide can achieve net zero emissions. The ultra-low emissions of blast furnace gas and the process of hydrogen desulfurization can be greatly simplified.

DETAILED DESCRIPTION

The technical solution of the present invention is described in detail below through specific embodiments, but the protection scope of the present invention is not limited to the embodiments.

Embodiment 1:

A blast furnace gas organic sulfur hydrolysis catalyst with strong acid gas resistance, and its preparation method is as follows:

(1) Dissolve 0.1 g of AgNO ₃ in 65 g of deionized water, take 100 g of Φ4-6 mm spherical γ-Al ₂ O ₃ carrier, and immerse an equal amount of the above AgNO ₃ aqueous solution.

(2) The impregnated catalyst samples were placed in the shade to dry for 6 hours.

(3) Soak the catalyst sample in 0.02 mol/L dilute hydrochloric acid for 2 h until the solution covers the solid particle catalyst sample.

(4) Filter out the catalyst sample soaked in the dilute hydrochloric acid, and then rinse the catalyst with deionized water to remove residual hydrochloric acid.

(5) After rinsing with deionized water, the catalyst sample was dried at 120°C to obtain the finished catalyst A.

Embodiment 2:

A blast furnace gas organic sulfur hydrolysis catalyst with strong acid gas resistance, and its preparation method is as follows:

(1) Dissolve 0.5 g of AgNO ₃ in 65 g of deionized water, take 100 g of Φ4-6 mm spherical γ-Al ₂ O ₃ carrier, and immerse an equal amount of the above AgNO ₃ aqueous solution.

(2) The impregnated catalyst samples were placed in the shade to dry for 12 hours.

(3) Soak the catalyst sample in 0.01 mol/L dilute hydrochloric acid for 1 hour until the solution covers the solid particle catalyst sample.

(4) Filter out the catalyst sample soaked in the dilute hydrochloric acid, and then rinse the catalyst with deionized water to remove residual hydrochloric acid.

(5) After rinsing with deionized water, the catalyst sample was dried at 130°C to obtain the finished catalyst B.

Embodiment 3:

A blast furnace gas organic sulfur hydrolysis catalyst with strong acid gas resistance, and its preparation method is as follows:

(1) Dissolve 0.8 g of AgNO ₃ in 65 g of deionized water, take 100 g of Φ4-6 mm spherical γ-Al ₂ O ₃ carrier, and soak an equal amount of the above AgNO ₃ aqueous solution.

(2) The impregnated catalyst samples were placed in the shade to dry for 24 hours.

(3) Soak the catalyst sample in 0.04 mol/L dilute hydrochloric acid for 4 h until the solution covers the solid catalyst particle sample.

(4) Filter out the catalyst sample soaked in the dilute hydrochloric acid, and then rinse the catalyst with deionized water to remove residual hydrochloric acid.

(5) After rinsing with deionized water, the catalyst sample was dried at 140°C to obtain the finished catalyst C.

Embodiment 4:

A blast furnace gas organic sulfur hydrolysis catalyst with strong acid gas resistance, and its preparation method is as follows:

(1) Dissolve 1.2 g of AgNO ₃ in 65 g of deionized water, take 100 g of Φ4-6 mm spherical γ-Al ₂ O ₃ carrier, and soak an equal amount of the above AgNO ₃ aqueous solution.

(2) The impregnated catalyst samples were placed in the shade to dry for 8 hours.

(3) Soak the catalyst sample in 0.05 mol/L dilute hydrochloric acid for 1 hour until the solution covers the solid particle catalyst sample.

(4) Filter out the catalyst sample soaked in the dilute hydrochloric acid, and then rinse the catalyst with deionized water to remove residual hydrochloric acid.

(5) After rinsing with deionized water, the catalyst sample was dried at 150°C to obtain the finished catalyst D.

Embodiment 5:

A blast furnace gas organic sulfur hydrolysis catalyst with strong acid gas resistance, and its preparation method is as follows:

(1) Dissolve 1.6 g of AgNO ₃ in 65 g of deionized water, take 100 g of Φ4-6 mm spherical γ-Al ₂ O ₃ carrier, and immerse an equal amount of the above AgNO ₃ aqueous solution.

(2) The impregnated catalyst samples were placed in the shade to dry for 8 hours.

(3) Soak the catalyst sample in 0.02 mol/L dilute hydrochloric acid for 3 h until the solution covers the solid particle catalyst sample.

(4) Filter out the catalyst sample soaked in the dilute hydrochloric acid, and then rinse the catalyst with deionized water to remove residual hydrochloric acid.

(5) After rinsing with deionized water, the catalyst sample was dried at 125°C to obtain the finished catalyst E.

Embodiment 6:

A blast furnace gas organic sulfur hydrolysis catalyst with strong acid gas resistance, and its preparation method is as follows:

(1) Dissolve 2.0 g of AgNO ₃ in 65 g of deionized water, take 100 g of Φ4-6 mm spherical γ-Al ₂ O ₃ carrier, and immerse an equal amount of the above AgNO ₃ aqueous solution.

(2) The impregnated catalyst samples were placed in the shade to dry for 10 hours.

(3) Soak the catalyst sample in 0.01 mol/L dilute hydrochloric acid for 2 h until the solution covers the solid particle catalyst sample.

(4) Filter out the catalyst sample soaked in the dilute hydrochloric acid, and then rinse the catalyst with deionized water to remove residual hydrochloric acid.

(5) After rinsing with deionized water, the catalyst sample was dried at 130°C to obtain the finished catalyst F.

Embodiment 7:

A blast furnace gas organic sulfur hydrolysis catalyst with strong acid gas resistance, and its preparation method is as follows:

(1) Dissolve 0.3 g of AgNO ₃ in 65 g of deionized water, take 100 g of Φ4-6 mm spherical γ-Al ₂ O ₃ carrier, and soak an equal amount of the above AgNO ₃ aqueous solution.

(2) The impregnated catalyst samples were placed in the shade to dry for 16 hours.

(3) Soak the catalyst sample in 0.03 mol/L dilute hydrochloric acid for 1 hour until the solution covers the solid particle catalyst sample.

(4) Filter out the catalyst sample soaked in the dilute hydrochloric acid, and then rinse the catalyst with deionized water to remove residual hydrochloric acid.

(5) After rinsing with deionized water, the catalyst sample was dried at 140°C to obtain the finished catalyst G.

Embodiment 8:

A blast furnace gas organic sulfur hydrolysis catalyst with strong acid gas resistance, and its preparation method is as follows:

(1) Dissolve 1.0 g of AgNO ₃ in 65 g of deionized water, take 100 g of Φ4-6 mm spherical γ-Al ₂ O ₃ carrier, and immerse an equal amount of the above AgNO ₃ aqueous solution.

(2) The impregnated catalyst samples were placed in the shade to dry for 16 hours.

(3) Soak the catalyst sample in 0.03 mol/L dilute hydrochloric acid for 1 hour until the solution covers the solid particle catalyst sample.

(4) Filter out the catalyst sample soaked in the dilute hydrochloric acid, and then rinse the catalyst with deionized water to remove residual hydrochloric acid.

(5) After rinsing with deionized water, the catalyst sample was dried at 140°C to obtain the finished catalyst H.

Comparative Example 1:

According to the method of Chinese patent CN 1069673A (normal temperature organic sulfur hydrolysis catalyst and preparation)

Dissolve 15g K ₂ CO ₃ in 65g deionized water, take 100g Φ4-6mm spherical γ-Al ₂ O ₃ carrier, and soak an equal amount of the above K ₂ CO ₃ aqueous solution. The impregnated catalyst sample is placed in the shade to dry for 4h, and finally dried at 120℃ for 4h to obtain comparative sample I.

Activity and stability evaluation results of catalyst samples:

30 mL of the above original particle size catalyst was loaded into a glass reactor with an inner diameter of Φ30 mm. The evaluation gas source simulated the composition of blast furnace gas: CO 22%, CO ₂ 20%, H ₂ 2%, O ₂ 0.5%, H ₂ O 4%, HCl 0.1%, N ₂ ～50%, COS 200 ppm, H ₂ S 50 ppm, the space velocity was 1000 h ^-1 , the reaction temperature was 120°C, and the COS hydrolysis conversion rate was taken as the evaluation index. The results are shown in Table 1.

Table 1 COS hydrolysis conversion rate of catalysts prepared in various examples (%)

Time (h) 4 12 twenty four 36 48 60 72 84 96 Catalyst A 97.2 97.4 97.1 96.9 96.9 96.8 96.6 96.8 96.8 Catalyst B 99.9 99.9 99.9 99.9 99.9 99.9 99.9 99.9 99.9 Catalyst C 99.9 99.9 99.9 99.9 99.9 99.9 99.9 99.9 99.9 Catalyst D 99.9 99.9 99.9 99.9 99.9 99.9 99.9 99.9 99.9 Catalyst E 99.9 99.9 99.9 99.9 99.9 99.9 99.9 99.9 99.9 Catalyst F 99.9 99.9 99.9 99.9 99.9 99.9 99.9 99.9 99.9 Catalyst G 98.8 98.6 98.8 98.5 98.7 98.2 98.4 98.2 98.5 Catalyst H 99.9 99.9 99.9 99.9 99.9 99.9 99.9 99.9 99.9 Comparison Sample I 99.9 99.1 97.3 96.2 94.8 90.5 85.4 78.2 67.2

Through comparison and analysis of examples, it is found that the hydrolysis activity of the organic sulfur hydrolysis catalyst for blast furnace gas prepared by the present invention is more stable, indicating that it has stronger ability to resist acidic gas and better stability.

The catalyst has been used in a pilot side stream test on blast furnace gas in a domestic steel plant, and the pilot life has exceeded half a year. Some pilot test data are shown in Table 2. The specific operating conditions are as follows: CO 20-25%, CO ₂ 18-22%, H ₂ 1.5-2.2%, O ₂ 0.2-0.5%, H ₂ O 3-4%, HCl 0.002-0.01%, N ₂ ~50%, COS 20-50ppm, H ₂ S 20-80ppm, space velocity 1000h ^-1 , reaction temperature 120°C.

Table 2. Pilot test data

Claims (10)

1. A preparation method of a high acid gas resistant blast furnace gas organic sulfur hydrolysis catalyst is characterized by comprising the following steps: the method comprises the following steps:

in the form of spherical gamma-Al ₂ O ₃ Carrier, first soaking AgNO with 0.1-3% mass percentage content in equivalent quantity ₃ The solution is placed in the shade for drying, and then is soaked by 0.01 to 0.05mol/L dilute hydrochloric acid for treatment, and the high acid gas resistant blast furnace gas organic sulfur hydrolysis catalyst is obtained after post-treatment.

2. The method of claim 1, wherein: spherical gamma-Al ₂ O ₃ The particle size of the carrier is 4-6 mm, and the specific surface area is 150-250 m ² /g。

3. The method of claim 1, wherein: agNO ₃ The mass percentage of the solution is 0.1-1%.

4. The method of claim 1, wherein: the mixture is placed in the shade for drying for 4 to 24 hours, and the soaking treatment time of the dilute hydrochloric acid is 1 to 4 hours.

5. The method of claim 1, wherein: the post-treatment comprises the following steps: washing the catalyst with deionized water to remove residual hydrochloric acid, and drying at 120-150 ℃.

6. The application of the blast furnace gas organic sulfur hydrolysis catalyst with high acid gas resistance in the blast furnace gas organic sulfur hydrolysis is characterized in that: the high acid gas resistant blast furnace organic sulfur hydrolysis catalyst adopts spherical gamma-Al ₂ O ₃ The carrier is AgCl, and the loading capacity of the AgCl is 0.08-2.6 wt%.

7. Use according to claim 6, characterized in that: the high acid gas resistant blast furnace gas organosulfur hydrolysis catalyst is produced by the production method described in any one of claims 1 to 5.

8. Use according to claim 6, characterized in that: the blast furnace gas contains acid gas, and the acid gas is at least one of HCl and HCN.

9. Use according to claim 6, characterized in that: the content of the acid gas is 0.0001-0.01%.

10. Use according to claim 6, characterized in that: the catalytic hydrolysis temperature of the organic sulfur hydrolysis catalyst is 80-150 ℃.