阅读说明：本技术 一种高炉煤气光催化水解精脱硫的方法 (Method for blast furnace gas photocatalytic hydrolysis fine desulfurization ) 是由 王学谦 周菲 王郎郎 蔡君 于 2020-12-29 设计创作，主要内容包括：本发明提供了一种高炉煤气光催化水解精脱硫的方法,该方法是将除尘后的高炉煤气冷却至50-150℃后,通入气固光催化反应器中,在水蒸气、光照、催化剂同时存在条件下对高炉煤气中的有机硫进行光催化氧化和水解反应,将高炉煤气中的有机硫水解氧化为无机硫,反应后气体再通过无机硫脱除装置,脱除无机硫,脱硫处理后的高炉煤气进入煤气管网使用；发明采用两步法对高炉煤气中的有机硫和无机硫进行源头治理,提高了脱硫效果,实现精脱硫；高炉煤气脱硫后再清洁利用,使得燃烧后的SO-2浓度可以达到污染物排放限值,从而减少了生态环境污染,提高了资源利用率。(The invention provides a blast furnace gas photocatalytic hydrolysis fine desulfurization method, which comprises the steps of cooling blast furnace gas after dust removal to 50-150 ℃, introducing the blast furnace gas into a gas-solid photocatalytic reactor, carrying out photocatalytic oxidation and hydrolysis reaction on organic sulfur in the blast furnace gas under the conditions of simultaneous existence of steam, illumination and a catalyst, carrying out hydrolytic oxidation on the organic sulfur in the blast furnace gas to inorganic sulfur, removing the inorganic sulfur from the gas after the reaction by an inorganic sulfur removal device, and enabling the blast furnace gas after desulfurization to enter a gas pipe network for use; the invention adopts a two-step method to treat the organic sulfur and the inorganic sulfur in the blast furnace gas from the source, thereby improving the desulfurization effect and realizing the fine desulfurization; the blast furnace gas is cleaned and utilized after being desulfurized, SO that the SO after combustion 2 The concentration can reach the pollutant emission limit value, thereby reducing the ecological environment pollution and improving the resource utilization rate.)

1. A method for blast furnace gas photocatalytic hydrolysis fine desulfurization is characterized in that: cooling the blast furnace gas after dust removal to 50-150 ℃, introducing the blast furnace gas into a gas-solid photocatalytic reactor, carrying out photocatalytic oxidation and hydrolysis reaction on organic sulfur in the blast furnace gas under the conditions of simultaneous existence of steam, illumination and a catalyst, carrying out hydrolytic oxidation on the organic sulfur in the blast furnace gas to inorganic sulfur, removing the inorganic sulfur from the gas after the reaction by an inorganic sulfur removal device, and enabling the blast furnace gas after desulfurization to enter a gas pipe network for use.

2. The method for blast furnace gas photocatalytic hydrolysis fine desulfurization according to claim 1, characterized in that: blast furnace gas at a space velocity of 100-3000 h^-1And (3) entering a gas-solid photocatalytic reactor, wherein the reaction temperature in the gas-solid photocatalytic reactor is 50-150 ℃.

3. The method for blast furnace gas photocatalytic hydrolysis fine desulfurization according to claim 1, characterized in that: in the gas-solid photocatalytic reactor, the volume percentage of water vapor in the gas is 5-6%.

4. The method for blast furnace gas photocatalytic hydrolysis fine desulfurization according to claim 1, characterized in that: the catalyst in the gas-solid photocatalytic reactor is BiWO₆-TiO₂Modified photocatalyst, Cu-KOH/gamma-Al₂O₃Modified photocatalyst, Cu-Ce-loaded ZrO₂Catalyst, Bi-KOH/TiO₂One of the modified photocatalysts.

5. The method for blast furnace gas photocatalytic hydrolysis fine desulfurization according to claim 4, characterized in that BiWO₆-TiO₂The preparation process of the modified photocatalyst comprises the following steps:

(1) mixing 18-24 mL of absolute ethanol and 5-7 mL of tetra-n-butyl phthalate, stirring at 20-40 ℃ for 30min, adding 0.75-1 mL of acetylacetone and 0.75-1 mL of nitric acid, continuously stirring, adjusting the pH to 6-10 with ammonia water, heating to 70 ℃ at a speed of 20 ℃/h to gel state to obtain sol TiO₂；

(2) Adding the sol TiO of the step (1) into a bismuth tungstate solution with the mass concentration of 1-10%₂Stirring uniformly, transferring into a high-pressure reaction kettle, reacting for 12-24 h at 160-220 ℃, centrifuging, filtering, washing for 2-3 times by using an ethanol solution with the volume concentration of 25%, drying for 6-12 h at 60-80 ℃, and calcining for 2-4 h at 350-450 ℃ to obtain BiWO₆-TiO₂A modified photocatalyst.

6. The method for blast furnace gas photocatalytic hydrolysis fine desulfurization according to claim 1, characterized in that: an ultraviolet lamp is arranged in the gas-solid photocatalytic reactor.

Technical Field

The invention belongs to the technical field of gas treatment, and particularly relates to a method for blast furnace gas photocatalytic hydrolysis fine desulfurization.

Background

Blast furnace gas is a byproduct gas in the steel making process, and the amount of the blast furnace gas is 1300-1600 m per ton of steel and iron produced³Blast furnace gas generation; blast furnace gas contains a lot of impurities, such as sulfide, oxygen and the like, wherein the sulfide content is high and the variety is various; these sulfur-containing gases tend to be malodorous and highly toxic, having serious environmental and human health implications. Wherein over 90% of the organic sulfur is COS, and the existence of the gases can not only corrode facilities in the process and poison catalysts, but also cause combustion products SO through direct combustion₂And (4) excessive emission. From the perspective of safe production and environmental protection, desulfurization and purification are the premise of realizing standard discharge and resource utilization of blast furnace gas. At present, the blast furnace gas desulfurization and purification part has no ready-to-use and identifiable technical scheme at home, and under the requirement of ultralow emission, an economic and feasible desulfurization process is urgently needed by steel enterprises. The blast furnace gas desulfurization technology is a new development direction, and due to the particularity of the blast furnace gas, the blast furnace gas cannot be directly applied and used in a mature desulfurization technology, so that the exploration and development of a desulfurization process suitable for the blast furnace gas are very necessary.

According to the current research situation of organic sulfur COS and the like, a wet method or a dry method mainly comprising hydrolysis is generally adopted as a removing method, the wet method is mainly applied to the crude desulfurization of blast furnace gas due to limited removing efficiency, the hydrolysis can be carried out at low temperature, and more than 90% of COS can be converted into H at 60 DEG C₂And S, the method is widely applied to improve the removal rate of COS. However, the method needs to adopt a multi-stage hydrolysis mode to remove hydrogen sulfide generated by the first-stage hydrolysis, enters the second-stage hydrolysis after the hydrolysis balance is broken, reestablishes a new balance, and repeats the steps to reduce the COS concentration to 0.1 mg/Nm³The following. The corresponding hydrolysis structures required by the multistage hydrolysis are more, the investment is large, and the operation cost is high.

The prior art CN110218590A discloses a blast furnace gas desulfurization method and a system, wherein the blast furnace gas desulfurization method comprises the following steps: 1) introducing the compressed feed gas into a hydrolysis tower to hydrolyze organic sulfur to generate mixed gas containing hydrogen sulfide; 2) introducing the mixed gas containing hydrogen sulfide into a pressure swing adsorption carbon dioxide purification device for coarse desulfurization to obtain coarse desulfurization gas, and performing adsorbent desorption on the adsorbent adsorbing carbon dioxide and hydrogen sulfide; 3) introducing the crude desulfurization gas into a fine desulfurization tower for fine desulfurization to obtain fine desulfurization gas; 4) and introducing the fine desulfurization gas into a pressure swing adsorption carbon monoxide purification working section, and purifying the carbon monoxide to obtain the desulfurized blast furnace gas. However, in the practical production and application process, the oxygen content in the blast furnace gas is high, and the excessively high oxygen content easily causes oxygen poisoning of the hydrolytic agent in the hydrolysis tower, so that the hydrolytic agent needs to be frequently replaced, and the desulfurization process and the desulfurization effect are affected.

The invention CN111732976A discloses a blast furnace gas desulfurization method and a system, and the blast furnace gas desulfurization method comprises the following steps: 1) deoxidizing blast furnace gas to obtain raw gas after deoxidation treatment; 2) hydrolyzing the deoxidized feed gas under the action of a hydrolyzing agent to obtain a hydrolyzed feed gas; 3) and (4) carrying out adsorption treatment on the hydrolyzed raw material gas by using an adsorbent to obtain desulfurized blast furnace gas. The method separately performs deoxidation treatment before hydrolysis treatment, so that equipment investment is high and industrial cost is increased.

Disclosure of Invention

The invention aims at that the existing blast furnace gas desulfurization process needs a multi-stage hydrolysis device in the stage of catalyzing and hydrolyzing organic sulfur, has higher investment cost and is not beneficial to industrial application, meanwhile, the method for the photocatalytic hydrolysis fine desulfurization of blast furnace gas is provided to avoid the problems of the counter-vulcanization phenomenon generated in the use process of the catalyst by the over-high oxygen content in the raw materials, the reduction of the activity of the catalyst and the like, the method adopts the combination of catalytic hydrolysis and photocatalysis, fully utilizes oxygen in the raw material gas on the basis of organic sulfur hydrolysis, under the condition of ultraviolet illumination, strong oxidizing substances such as hydroxyl free radicals and the like are generated through photoreaction to oxidize organic sulfur, thereby effectively avoiding the poisoning phenomenon of the hydrolysis catalyst caused by oxygen, and in the process of removing the organic sulfur in the first desulfurization unit, the integration of catalytic hydrolysis and photocatalysis of COS is realized, and organic sulfur is completely converted into inorganic sulfur; and the inorganic sulfur is removed by the existing mature desulfurization process after the gas enters a subsequent device, so that the zero sulfur utilization of the blast furnace gas is realized.

The blast furnace gas photocatalytic hydrolysis fine desulfurization method comprises the steps of cooling the blast furnace gas after dust removal to 50-150 ℃, introducing the blast furnace gas into a gas-solid photocatalytic reactor, carrying out photocatalytic oxidation and hydrolysis reaction on organic sulfur in the blast furnace gas under the conditions of simultaneous existence of water vapor, illumination and a catalyst, carrying out hydrolytic oxidation on the organic sulfur in the blast furnace gas to inorganic sulfur, removing the inorganic sulfur from the gas after the reaction by an inorganic sulfur removal device, and allowing the blast furnace gas after desulfurization to enter a gas pipe network for use.

The blast furnace gas is used at an airspeed of 100-3000 h^-1And (3) entering a gas-solid photocatalytic reactor, wherein the reaction temperature in the gas-solid photocatalytic reactor is 50-150 ℃.

In the gas-solid photocatalytic reactor, the volume percentage of water vapor in the gas is 5-6%.

The catalyst in the gas-solid catalytic reactor is BiWO₆-TiO₂Modified photocatalyst, Cu-KOH/gamma-Al₂O₃Modified photocatalyst, Cu-Ce-loaded ZrO₂Catalyst, Bi-KOH/TiO₂One of the modified photocatalysts.

Wherein BiWO₆-TiO₂The preparation process of the modified photocatalyst comprises the following steps:

(1) mixing 18-24 mL of absolute ethanol and 5-7 mL of tetra-n-butyl phthalate, stirring at 20-40 ℃ for 30min, adding 0.75-1 mL of acetylacetone and 0.75-1 mL of nitric acid, continuously stirring for 30min, adjusting the pH to 6-10 with ammonia water, heating to 70 ℃ at a speed of 20 ℃/h to gel state to obtain sol TiO₂；

(2) Adding the sol TiO of the step (1) into a bismuth tungstate solution with the mass concentration of 1-10%₂Stirring uniformly, transferring into a high-pressure reaction kettle, reacting for 12-24 h at 160-220 ℃, centrifuging, filtering, washing for 2-3 times by using an ethanol solution with the volume concentration of 25%, drying for 6-12 h at 60-80 ℃, and calcining for 2-4 h at 350-450 ℃ to obtain BiWO₆-TiO₂A modified photocatalyst.

Cu-KOH /γ-Al₂O₃The modified photocatalyst is first referred to Kim D, Choi B, Park G, et Al. Effect of gamma-Al₂O₃ characteristics on hydrogen production of Cu/γ-Al₂O₃catalyst for steam reforming of dimethyl ether[J]Cu/gamma-Al was prepared by the method in Chemical Engineering Science, 2020, 216:115535₂O₃Activating the catalyst by using 0.1mol/L KOH solution for 1 hour, and drying to obtain Cu-KOH/gamma-Al₂O₃A modified photocatalyst.

ZrO loaded with Cu-Ce₂The catalyst refers to "Wangwei, Gaoyunjun, Panchun, Wanyidong, Xuyanhua" CuCeOx/TiO₂-ZrO₂Catalyst for catalytic wet oxidation treatment of aspartame production wastewater [ J]The method in Shandong chemical engineering, 2019,48(14): 246-.

Bi-KOH/TiO₂The modified photocatalyst refers to 'Caocaiping', Liyunjun, Meizimin, Cabernet Sauvignon, BiTiO/TiO₂Preparation of composite nanofiber and visible light catalytic performance [ J]Bi/TiO prepared by the method in the journal of inorganic chemistry, 2017,33(12):2225-2232 ″)₂Activating the catalyst by using 0.1mol/L KOH solution for 1 hour, and drying to obtain Bi-KOH/TiO₂A modified photocatalyst.

The organic sulfur concentration at the inlet of the gas-solid photocatalytic reactor is 140-160 mg/m³。

An ultraviolet lamp is arranged in the gas-solid photocatalytic reactor.

The principle of organic sulfur photocatalytic hydrolysis is that under illumination, a catalyst absorbs photons with energy less than or equal to the band gap width of the catalyst, electrons on a valence band are excited by the energy to jump to a conduction band to form photoproduction electrons, and an electron hole appears on the valence band; the photo-generated electron-hole pair has strong oxidation-reduction property, and under the action of coulomb force, electrons and holes migrate to the particle surface to react with water molecules around the catalyst, combined oxygen in the catalyst and adsorbed oxygen on the surface to generate strong oxidizing substances such as OH, OOH and the like, so that carbonyl sulfide is oxidized; the introduced water vapor and carbonyl sulfide are subjected to hydrolysis reaction, and the generated product passes through an inorganic sulfur removal device to remove inorganic sulfur.

The inorganic sulfur is hydrogen sulfide, sulfur dioxide and the like, the inorganic sulfur removal method comprises the conventional methods such as wet desulfurization (oxidation method, chemical absorption method, physical absorption method and physical-chemical absorption method), dry desulfurization (catalytic oxidation method and adsorption method) and the like, and the adopted adsorbent and/or oxidation catalyst are reagents prepared according to the conventional method or conventional reagents.

The invention also comprises a step of regenerating the used hydrolytic agent and the adsorbent. The regeneration method is adopted to be N₂And carrying out thermal regeneration under the atmosphere to remove elemental sulfur covering the active sites of the catalyst and recover the active sites. And the regeneration step is to place the desulfurized catalyst at a high temperature of 350-450 ℃ and purge the catalyst for 6-12 hours by using nitrogen. The sulfur simple substance deposited in the pore canal of the desulfurizer is carried out by the nitrogen in the form of steam, thereby realizing the regeneration of active sites and active sites for absorbing oxygen, the regeneration and the cyclic utilization of the catalyst and effectively reducing the operation cost.

The method has the advantages and the technical effects that:

1. the photocatalytic hydrolysis coupling method is applied to blast furnace gas desulfurization, and has the advantages of mild reaction conditions, simple process, low investment, good desulfurization effect and the like;

2. the sulfur-containing gas is treated by the two-section desulfurization device arranged in series, so that the sulfur-containing concentration of the blast furnace gas entering a gas pipe network after desulfurization is lower than 0.1mg/m³；

3. The invention effectively solves the poisoning phenomenon of high-content oxygen in blast furnace gas on the hydrolysis catalyst, avoids the influence on the desulfurization process and the desulfurization effect, and greatly prolongs the service life of the hydrolytic agent;

4. the desulfurized catalyst is thermally regenerated in the nitrogen atmosphere, and the method is simple and easy to implement, and effectively saves the cost.

Drawings

FIG. 1 is a flow chart of the blast furnace gas photocatalytic hydrolysis fine desulfurization process of the present invention.

Detailed Description

The present invention is further illustrated by the following examples, but the scope of the invention is not limited to the above-described examples.

Example 1:

1、BiWO₆-TiO₂the modified photocatalyst was prepared as follows：

Mixing 20mL of anhydrous ethanol and 6mL of tetrabutyl phthalate, stirring at 30 ℃ for 30min, adding 1mL of acetylacetone and 0.75mL of nitric acid, continuously stirring for 30min, adjusting the pH to 7 with ammonia water, and heating to 70 ℃ at a speed of 20 ℃/h to gel state to obtain sol TiO₂(ii) a Adding sol TiO into 5 mass percent bismuth tungstate solution₂Stirring uniformly, transferring into a high-pressure reaction kettle, reacting for 15h at 200 ℃, centrifuging, filtering, washing with 25% ethanol solution by volume concentration for 3 times, drying for 12h at 60 ℃, and calcining for 4h at 350 ℃ to obtain BiWO₆-TiO₂Modifying a photocatalyst;

2. as shown in FIG. 1, the dedusted blast furnace gas was cooled to 70-80 deg.C, and the COS concentration in the gas was 140mg/m³Dust concentration 0.2mg/m³At an airspeed of 500h^-1Introducing into a reaction vessel with BiWO₆-TiO₂In a first-stage photocatalytic hydrolysis desulfurization device of a modified photocatalyst, steam is introduced at the same time, the volume percentage of the steam in the gas is 5 percent, the photocatalytic oxidation and hydrolysis reaction is carried out on organic sulfur in blast furnace gas under the conditions of steam, ultraviolet irradiation (the wavelength of an ultraviolet lamp is 185nm, the power is 9W) and the existence of the catalyst at the same time, the reaction temperature is 80 ℃, and the concentration of COS in the reacted gas is lower than 0.1mg/m³，H₂The S concentration is 140mg/m³(ii) a Then sending the mixture into a second-stage inorganic sulfur removal device (dry desulfurization system), wherein the dry desulfurization system is a catalytic oxidation desulfurization device and is internally provided with a Cu-doped activated carbon modified catalyst (refer to the modification conditions of the activated carbon and the influence of the modification conditions on the adsorption performance of hydrogen sulfide [ J]Chemical development, 2012,31(03):676-₂S is directly oxidized into elemental sulfur by air on a catalyst to form a gas flow IV, the concentration of COS is 0mg/m³Hydrogen sulfide concentration of 0mg/m³And the purified blast furnace gas enters a gas pipe network.

Example 2:

cooling the dedusted blast furnace gas to 80-90 deg.C, wherein the COS concentration in the gas is 150mg/m³Dust concentration 0.2mg/m³At a space velocity of 600h^-1Introducing a gas containing Cu-KOH/gamma-Al₂O₃In a first-stage photocatalytic hydrolysis desulfurization device of a modified photocatalyst, steam is introduced at the same time, the volume percentage of the steam in the gas is 5.5 percent, organic sulfur in blast furnace gas is subjected to photocatalytic oxidation and hydrolysis reaction under the conditions of steam, ultraviolet irradiation (the wavelength of an ultraviolet lamp is 185nm, the power is 9W) and the existence of the catalyst at the same time, the reaction temperature is 90 ℃, and the concentration of COS in the reacted gas is lower than 0.1mg/m³The concentration of hydrogen sulfide is 149mg/m³(ii) a Then sending the mixture into a second-stage inorganic sulfur removal device (dry desulfurization system), wherein the dry desulfurization system is an adsorption desulfurization tower, and a copper-doped activated carbon modified adsorbent (refer to the modification conditions of activated carbon and the influence thereof on the adsorption performance of hydrogen sulfide [ J]The chemical engineering progress, 2012,31(03):676 and 680. ") is used for adsorbing and removing the residual inorganic sulfur and partial dust in the airflow, and the concentration of the COS after the treatment is 0mg/m³Hydrogen sulfide concentration of 0mg/m³The purified blast furnace gas enters a gas pipe network;

this example Cu-KOH/γ -Al₂O₃The modified photocatalyst is first referred to Kim D, Choi B, Park G, et Al. Effect of gamma-Al₂O₃ characteristics on hydrogen production of Cu/γ-Al₂O₃ catalyst for steam reforming of dimethyl ether[J]Cu/gamma-Al was prepared by the method in Chemical Engineering Science, 2020, 216:115535₂O₃Activating the catalyst by using 0.1mol/L KOH solution for 1 hour, and drying the catalyst at 80 ℃ to obtain Cu-KOH/gamma-Al₂O₃A modified photocatalyst.

Example 3:

cooling the dedusted blast furnace gas to 90-100 deg.C, wherein the COS concentration in the gas is 160mg/m³Dust concentration 0.3 mg/m³At a space velocity of 700h^-1Introducing ZrO loaded with Cu-Ce₂In the first-stage photocatalytic hydrolysis desulfurization device of the catalyst, water vapor is introduced at the same time, the volume percentage of the water vapor in the gas is 5.7 percent, and organic sulfur in blast furnace gas is subjected to photocatalytic oxidation and photocatalytic oxidation under the conditions of the simultaneous existence of the water vapor, ultraviolet irradiation (the wavelength of an ultraviolet lamp is 185nm, and the power is 9W) and the catalystHydrolysis reaction at 100 deg.C to obtain COS concentration of less than 0.1mg/m³The concentration of hydrogen sulfide was 158mg/m³Dust concentration 16mg/m³(ii) a Then sending the mixture into a secondary inorganic sulfur removal device (wet desulphurization system), wherein the wet desulphurization system is an alkali liquor absorption tower, NaOH alkali liquor is arranged in the absorption tower, double-tower desulphurization is carried out, and airflow enters from the lower part of the desulphurization tower and is in countercurrent contact with the alkali liquor sprayed by an upper spray gun; h in the gas stream₂S reacts with NaOH, thereby removing H in the coal gas₂S; the concentration of COS after treatment is 0mg/m³Hydrogen sulfide concentration of 0mg/m³The purified blast furnace gas enters a gas pipe network;

example Cu-Ce Supported ZrO₂The catalyst refers to "Wangwei, Gaoyunjun, Panchun, Wanyidong, Xuyanhua" CuCeOx/TiO₂-ZrO₂Catalyst for catalytic wet oxidation treatment of aspartame production wastewater [ J]The method in Shandong chemical engineering, 2019,48(14): 246-.

Example 4:

cooling the blast furnace gas after dust removal to 110-120 ℃, wherein the concentration of COS in the gas is 150mg/m³Dust concentration 0.2mg/m³At an airspeed of 800h^-1Introducing a gas containing Bi-KOH/TiO₂In a first-stage photocatalytic hydrolysis desulfurization device of a modified photocatalyst, steam is introduced at the same time, the volume percentage of the steam in the gas is 5.7 percent, organic sulfur in blast furnace gas is subjected to photocatalytic oxidation and hydrolysis reaction under the conditions of steam, ultraviolet irradiation (the wavelength of an ultraviolet lamp is 185nm, the power is 9W) and the existence of the catalyst at the same time, the reaction temperature is 120 ℃, and the concentration of COS in the reacted gas is lower than 0.1mg/m³The concentration of hydrogen sulfide is 149mg/m³(ii) a Then sending the mixture into a second-stage inorganic sulfur removal device (dry desulfurization system), wherein the dry desulfurization system is an adsorption desulfurization tower, and a copper-doped activated carbon modified adsorbent (refer to the modification conditions of activated carbon and the influence thereof on the adsorption performance of hydrogen sulfide [ J]The chemical engineering progress, 2012,31(03):676 and 680. "prepared by the method) is used for adsorbing and removing the residual inorganic sulfur and partial dust in the gas flow; the concentration of COS in the treated gas stream is 0mg/m³Hydrogen sulfide concentration of 0mg/m³After purificationThe blast furnace gas enters a gas pipe network;

the Bi-KOH/TiO₂The modified photocatalyst refers to 'Caocaiping', Liyunjun, Meizimin, Cabernet Sauvignon, BiTiO/TiO₂Preparation of composite nanofiber and visible light catalytic performance [ J]Bi/TiO prepared by the method in the journal of inorganic chemistry, 2017,33(12):2225-2232 ″)₂Activating the catalyst by using 0.1mol/L KOH solution for 1 hour, and drying the catalyst at 70 ℃ to obtain Bi-KOH/TiO₂A modified photocatalyst.