Method for removing organic sulfur in blast furnace gas
阅读说明：本技术 一种脱除高炉煤气中有机硫的方法 (Method for removing organic sulfur in blast furnace gas ) 是由 王学谦 蔡君 王郎郎 于 2020-12-29 设计创作，主要内容包括：本发明公开了一种脱除高炉煤气中有机硫的方法,属于光催化剂技术领域,本发明方法首先采用水热法制备得到复合材料,然后采用浸渍法制备多元复合材料；利用多元复合光催化剂对高炉煤气进行处理,实现高炉煤气中有机硫的脱除；复合催化剂具有比表面积增加,光生载流子复合率降低等特点,大大提高了光催化效率,本发明的二氧化钛基多元复合材料具有大的比表面积和优异的光催化性能,能高效的脱除高炉煤气中的COS。(The invention discloses a method for removing organic sulfur in blast furnace gas, belonging to the technical field of photocatalysts, and the method comprises the steps of firstly preparing a composite material by a hydrothermal method, and then preparing a multi-element composite material by an immersion method; the blast furnace gas is treated by the multielement composite photocatalyst, so that the organic sulfur in the blast furnace gas is removed; the composite catalyst has the characteristics of increased specific surface area, reduced recombination rate of photon-generated carriers and the like, greatly improves the photocatalytic efficiency, and the titanium dioxide-based multielement composite material has large specific surface area and excellent photocatalytic performance and can efficiently remove COS in blast furnace gas.)
1. A method for removing organic sulfur in blast furnace gas is characterized in that: the method comprises the following steps of (1) treating blast furnace gas by using a photocatalyst to remove organic sulfur in the blast furnace gas, wherein the preparation method of the composite photocatalyst comprises the following steps:
(1) 4-6g of urea is placed in a muffle furnace to be treated for 0.3-0.6h at the temperature of 550-650 ℃, or 4-6g of melamine is placed in the muffle furnace to be treated for 2-4h at the temperature of 500-600 ℃ to obtain g-C3N4Powder; then taking g-C3N4Adding 0.1-0.3g of the powder into 20mL of ethylene glycol, and uniformly stirring to obtain g-C3N4A solution;
(2) taking 5-7mL of g-C3N4Mixing the solution with 30-40mL of deionized water, carrying out ultrasonic treatment for 60min, adding 10-20mL of absolute ethyl alcohol, and continuing ultrasonic treatment for 1h to form a mixed solution; dripping 0.2-0.3g of tetrabutyl titanate into the mixed solution, performing magnetic stirring for 30-60min, performing ultrasonic treatment alternately for 30min, circulating for 2-3 times, and performing microwave hydrothermal treatment on the suspension at 150-200 ℃ for 20-60 min; naturally cooling to normal temperature after the treatment is finished, respectively washing the obtained product with absolute ethyl alcohol and deionized water for 3-4 times, and drying to obtain TiO2/g-C3N4A composite catalyst;
(3) taking TiO2/g-C3N4Adding 0.5-1g of composite catalyst into a triangular flask, adding 15-25mL of transition metal solution, uniformly mixing, placing the mixed suspension into an oil bath kettle at 70-90 ℃, heating and stirring for 1h, centrifuging, and taking precipitate; washing with deionized water and anhydrous ethanol for 3-5 times alternately, and vacuum drying at 60 deg.C for 24 hr to obtain ternary composite photocatalyst M/TiO2/g-C3N4M is Mn, Fe, Ni or Cu.
2. The method for removing organic sulfur in blast furnace gas according to claim 1, characterized in that: in the step (2), the temperature is increased to 150-200 ℃ at the temperature increase rate of 2-10 ℃/min.
3. The method for removing organic sulfur in blast furnace gas according to claim 1, characterized in that: the transition metal solution is MnCl3、FeCl3、NiCl2、CuCl2In the first step, the mass concentration of the transition metal solution is 1-10%.
Technical Field
The invention belongs to the technical field of adsorption-photocatalysis-atmosphere treatment, and particularly relates to a method for removing organic sulfur in blast furnace gas by catalytic degradation of an adsorption photocatalyst.
Background
With the consumption of energy, the energy conservation and the environmental pollution reduction are clean coal technologies advocated and promoted at present. The high organic sulfur content not only causes the corrosion of gas pipelines and equipment to be intensified, but also causes SO after the fuel gas is combusted2The emission exceeds the standard. Therefore, the coal gas desulfurization technology is one of the essential key technologies in clean conversion and utilization of coal. At present, the desulfurization technology for blast furnace gas has no mature technical route, and the main technical problem is that the existing form of sulfur in the blast furnace gas is complex, namely the sulfur is inorganic sulfur (H)2S), and is rich in COS and CS2Isoorganosulfur, organosulfur adsorption process and catalystThe reaction temperature of the chemical conversion method is generally higher, and the chemical conversion method is easy to cause a series of problems of reactor corrosion, catalyst poisoning and the like, thereby seriously restricting the resource utilization of blast furnace gas. In blast furnace gas, the sulfide is carbonyl sulfide (COS) and carbon disulfide (CS)2) Hydrogen sulfide (H)2S), thiol and thioether, mainly COS and H2S、CS2Mainly comprises COS accounting for about 45-85% of the total sulfur. Generally, the process for removing organic sulfur is more complicated and costly than inorganic sulfur, so that the low-cost, efficient and safe removal of sulfide from blast furnace gas is still a great technical problem and challenge. The key to realize the fine desulfurization is to effectively remove COS, and is also the main problem in the deep purification process of the industrial raw material gas.
The conventional COS removal methods are mainly classified into dry methods and wet methods. The wet process is relatively mature, but the equipment used in the desulfurization process is huge, the desulfurization load is large, the mass transfer resistance is large, the sulfur recovery difficulty is high, and the like, so that the wet process is mainly used for crude desulfurization, and currently, a chemical absorption method, a physical absorption method and an absorption oxidation method are mainly used; compared with wet desulphurization, the dry desulphurization has the advantages of relatively simple process flow, low cost and relatively high inorganic sulfur and organic sulfur removal progress, and the methods mainly applied at present comprise an adsorption method, a photolysis method, a hydrogenation method and a hydrolysis method; at present, the hydrolysis method is most applied, but the traditional hydrolysis method also needs certain conditions such as reaction temperature and the like, and needs certain energy consumption and the like.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a method for removing organic sulfur in blast furnace gas, which effectively removes the organic sulfur COS in the blast furnace gas through the synergy of adsorption and photocatalysis, and is beneficial to the fine desulfurization of the blast furnace gas and the subsequent utilization of the gas; the method utilizes titanium oxide as a carrier to prepare a series of photocatalysts to catalyze and remove COS; with TiO2The supported catalyst has high activity and mechanical strength under low-temperature illumination, but the specific surface area is small, so that the adsorption capacity is limited, therefore the invention utilizes TiO2High photocatalytic activity with carbon material (nitriding)Carbon, etc.) to compensate TiO2As the photocatalyst, the ultraviolet/visible adsorption-photocatalysis material with high specific surface area and high photocatalytic activity can be formed. Meanwhile, in order to improve the photocatalytic performance of the material, a first transition system metal site doping element (Fe, Mn and the like) is further adopted to prepare the ternary composite material M/TiO2/g-C3N4。
The method for removing organic sulfur in blast furnace gas of the invention is to treat the blast furnace gas by using a multi-element composite photocatalyst to realize the removal of organic sulfur in the blast furnace gas, wherein the preparation method of the multi-element composite photocatalyst comprises the following steps:
(1) 4-6g of urea is placed in a muffle furnace to be treated for 0.3-0.6h at the temperature of 550-650 ℃, or 4-6g of melamine is placed in the muffle furnace to be treated for 2-4h at the temperature of 500-600 ℃ to obtain g-C3N4Powder; then taking g-C3N4Pouring 0.1-0.3g of the powder into 20mL of ethylene glycol, and uniformly stirring to obtain g-C3N4A solution;
(2) taking 5-7mLg-C3N4Mixing the solution with 30-40mL of deionized water, carrying out ultrasonic treatment for 60min, adding 10-20mL of absolute ethyl alcohol, and continuing ultrasonic treatment for 1h to form a mixed solution; dripping 0.2-0.3g of tetrabutyl titanate into the mixed solution, performing magnetic stirring for 30-60min, performing ultrasonic treatment alternately for 30min, circulating for 2-3 times, and performing microwave hydrothermal treatment on the suspension at 150-200 ℃ for 20-60 min; naturally cooling to normal temperature after the treatment is finished, respectively washing the obtained product with absolute ethyl alcohol and deionized water for 3-4 times, and drying to obtain TiO2/g-C3N4A composite catalyst;
heating to 150-200 ℃ at a heating rate of 2-10 ℃/min;
(3) taking TiO2/g-C3N4Adding 0.5-1g of composite catalyst into a triangular flask, adding 15-25mL of transition metal solution, uniformly mixing, placing the mixed suspension into an oil bath kettle at 70-90 ℃, heating and stirring for 1h, centrifuging, and taking precipitate; washing with deionized water and anhydrous ethanol for 3-5 times alternately, and vacuum drying at 60 deg.C for 24 hr to obtain ternary composite photocatalyst M/TiO2/g-C3N4M is Mn, Fe, Ni or Cu.
The transition metal solution is MnCl3、FeCl3、NiCl2、CuCl2In the first step, the mass concentration of the transition metal solution is 1-10%.
The invention adopts a microwave hydrothermal method to prepare TiO2/g-C3N4Composite catalyst and method for obtaining M/TiO by impregnation2/g-C3N4The multi-component composite catalyst has the characteristics of increasing the specific surface area, reducing the recombination rate of photon-generated carriers and the like, so that the photocatalytic efficiency can be greatly improved.
The composite catalyst can be used for adsorbing-photocatalytic removal of COS, and the reaction mechanism is as follows:
M/TiO2/g-C3N4+hv→M/TiO2/g-C3N4 (e-+h+) （1）
H2O + hv → H + ·OH （2）
COS removal mechanism (air conditions):
COS → CO + S (dissociation) (3)
S+O2→SO+O （4）
O2(g)→O2ad （5）
O2ad+e-→·O2 - （6）
·O2 -+e-→2·O- （7）
·O-+COS→CO+SO （8）
·O+CO→CO2 （9）
·O+SO2→SO3 （10）
COS + ·OH → HSCO2 - （11）
HSCO2 + ·OH → H2S +CO2 （12）
According to the invention, by TiO2And g-C3N4And the transition metal is compounded to form the ternary composite photocatalytic material, and the prepared material has larger adsorption capacity and can exert high photocatalytic property. g-C3N4The larger specific surface area improves TiO2The defect of too small specific surface area provides more adsorption and catalytic active sites for the adsorption-photocatalysis process, and g-C3N4Has a band gap of 2.7eV, and can utilize sunlight in a wider range. Thus, use is made of g-C3N4Compounding to obtain TiO with high band gap and enhanced visible light absorption2The semiconductor photocatalyst can improve the adsorption-photocatalysis efficiency of pollutants; and the transition metal is doped to form a heterojunction, so that the recombination rate of a photon-generated carrier can be more effectively reduced, the effective separation of photon-generated electrons and holes is realized, the high-efficiency photocatalytic effect is realized, and the photocatalytic performance of the material can be greatly improved.
In the invention, the compounding of the carbon nitride effectively solves the problem of pure TiO2The defect of small specific surface area greatly increases the adsorption performance of the composite material, thereby increasing more active sites for photocatalytic reaction; in the process of multi-element compounding, the doping of the transition metal provides an effective electron acceptor, and by capturing photoproduction electrons formed in titanium dioxide, the recombination rate of the photoproduction electrons and holes can be effectively reduced, the migration efficiency of the photoproduction electrons is improved, more active species are formed, the catalysis efficiency is further improved, and pollutants are removed through more efficient catalysis.
The doping of the transition element can extend the light absorption range of the material to the visible range, and can improve the utilization efficiency of light.
The invention has the beneficial effects that:
(1) the preparation method of the catalyst is simple and low in cost, and the material prepared by the microwave hydrothermal method and the impregnation method has better photocatalytic performance;
(2) the invention utilizes the unique planar structure of carbon nitride, excellent electronic conductivity, low cost and flexibility, and changes the crystal structure of semiconductor by doping transition elements to prepare the multielement nano TiO2A composite nanomaterial;
(3) the M/TiO with low cost and excellent performance is prepared by the reaction conditions of a microwave hydrothermal method and an impregnation method2/g-C3N4A ternary composite material;
(4) the composite material prepared by the invention is applied to the high-efficiency adsorption-photocatalytic removal of COS in blast furnace gas, and shows high activity and stability in the removal process, which shows that the catalyst has good application prospect in the field of removal of organic sulfides in the blast furnace gas;
(5) in the preparation process of the material, substances such as a surfactant with high toxicity and high hazard are not involved, and the preparation process is green and environment-friendly.
Detailed Description
The present invention will be described in further detail with reference to the following examples, but the scope of the present invention is not limited to the examples.
Example 1: the method for adsorbing and photocatalytic purifying the organic sulfur in blast furnace gas by using the titanium dioxide-based material comprises the following specific steps:
(1) treating 5.0g urea in muffle furnace at 600 deg.C for 0.5h, and collecting g-C3N4Adding 0.2g of the powder into 20mL of ethylene glycol, and stirring to obtain g-C3N4A solution;
(2) take 6mLg-C3N4Mixing with 35mL of deionized water, carrying out ultrasonic treatment for 60min, adding 15mL of absolute ethyl alcohol, and continuing ultrasonic treatment for 1h to form a mixed solution; dripping 0.25g of tetrabutyl titanate into the mixed solution, performing magnetic stirring for 30min, performing ultrasonic treatment alternately, performing ultrasonic treatment for 30min, circulating for 2 times, putting the suspension into a hydrothermal kettle, heating at a heating rate of 5 ℃/min, and performing microwave hydrothermal treatment at 150 ℃ for 50 min; naturally cooling to normal temperature after the treatment is finished, and adding absolute ethyl alcohol into the obtained productWashing with deionized water for 3 times, and oven drying at 60 deg.C for 12 hr to obtain TiO2/g-C3N4A composite catalyst;
(3) taking TiO2/g-C3N40.5g of composite catalyst is put into a triangular flask, and 15mL of MnCl with the mass concentration of 2 percent is added3Uniformly mixing the solution, placing the mixed suspension in an oil bath kettle at 70 ℃, heating and stirring for 1h, centrifuging, and taking a precipitate; washing with deionized water and anhydrous ethanol alternately for 3 times, and vacuum drying at 60 deg.C for 24 hr to obtain ternary composite photocatalyst Mn/TiO2/g-C3N4；
And (3) detecting the catalytic performance: 0.1g of the ternary composite photocatalyst Mn/TiO prepared in this example was weighed2/g-C3N4The device is used for researching the COS in the photocatalytic desorption simulation smoke under the ultraviolet lamp, and the simulation smoke is as follows: 0.1% of O2The concentration of the COS inlet is 150ppm, the gas flow rate is 200mL/min, the reaction temperature is 30 ℃, the wavelength of an ultraviolet lamp is 254nm, the power of the ultraviolet lamp is 9W, and the model is TUV PL-S, Philips and Netherlands; the experimental results showed that the material prepared in this example had a COS removal efficiency of 83%.
Example 2: the method for adsorbing and photocatalytic purifying the organic sulfur in blast furnace gas by using the titanium dioxide-based material comprises the following specific steps:
(1) treating 5.0g melamine in muffle furnace at 550 deg.C for 3 hr, and collecting g-C3N40.2g of the powder was put into 20mL of ethylene glycol and stirred to obtain g-C3N4A solution;
(2) take 5mLg-C3N4Mixing the solution with 40mL of deionized water, carrying out ultrasonic treatment for 60min, adding 20mL of absolute ethyl alcohol, and continuing ultrasonic treatment for 1h to form a mixed solution; dripping 0.2g of tetrabutyl titanate into the mixed solution, performing magnetic stirring for 40min, performing ultrasonic treatment alternately, performing ultrasonic treatment for 30min, circulating for 3 times, putting the suspension into a hydrothermal kettle, heating at a heating rate of 5 ℃/min, and performing microwave hydrothermal treatment for 30min at 200 ℃; naturally cooling to normal temperature after the treatment is finished, respectively washing the obtained product with absolute ethyl alcohol and deionized water for 3 times, and drying in an oven at 60 ℃ for 12 hours to obtain TiO2/g-C3N4A composite catalyst;
(3) taking TiO2/g-C3N40.8g of composite catalyst is put into a triangular flask, and 20mL of FeCl with the mass concentration of 5 percent is added3Uniformly mixing the solution, placing the mixed suspension in an oil bath kettle at the temperature of 80 ℃, heating and stirring for 1 hour, centrifuging, and taking a precipitate; washing with deionized water and absolute ethyl alcohol alternately for 4 times, and vacuum drying at 60 deg.C for 24h to obtain the final product2/g-C3N4；
And (3) detecting the catalytic performance: 0.1g of the ternary composite photocatalyst Fe/TiO prepared in the example was weighed2/g-C3N4The device is used for researching the COS in the photocatalytic desorption simulation smoke under the ultraviolet lamp, and the simulation smoke is as follows: 0.1% of O2The concentration of the COS inlet is 150ppm, the gas flow rate is 200mL/min, the wavelength of an ultraviolet lamp is 254nm, the reaction temperature is 30 ℃, the power of the ultraviolet lamp is 9W, and the model is TUV PL-S, Philips and Netherlands; the experimental results showed that the material prepared in this example had an efficiency of removing COS of 84%.
Example 3: the method for adsorbing and photocatalytic purifying the organic sulfur in blast furnace gas by using the titanium dioxide-based material comprises the following specific steps:
(1) 6g of urea is put into a muffle furnace to be treated for 0.3h at 650 ℃, and then g-C is taken3N40.3g of the powder is put into 20mL of glycol to be evenly stirred to prepare g-C3N4Solutions of
(2) Take 5mLg-C3N4Mixing the solution with 40mL of deionized water, carrying out ultrasonic treatment for 60min, adding 20mL of absolute ethyl alcohol, and continuing ultrasonic treatment for 1h to form a mixed solution; dripping 0.3g of tetrabutyl titanate into the mixed solution, performing magnetic stirring for 50min, performing ultrasonic treatment alternately, performing ultrasonic treatment for 30min, circulating for 2 times, putting the suspension into a hydrothermal kettle, heating at a heating rate of 5 ℃/min, and performing microwave hydrothermal treatment at 180 ℃ for 40 min; naturally cooling to normal temperature after the treatment is finished, respectively washing the obtained product with absolute ethyl alcohol and deionized water for 3 times, and drying to obtain TiO2/g-C3N4A composite catalyst;
(3) taking TiO2/g-C3N4Adding 1g of composite catalyst into an Erlenmeyer flask, and adding 25mL of the composite catalystNiCl with a degree of 8%2After uniformly mixing the solution, placing the mixed suspension in an oil bath kettle at 90 ℃, heating and stirring for 1h, centrifuging at 8000rpm, and taking a precipitate; washing with deionized water and anhydrous ethanol alternately for 5 times, and vacuum drying at 60 deg.C for 24h to obtain ternary composite photocatalyst Ni/TiO2/g-C3N4；
And (3) detecting the catalytic performance: 0.1g of the ternary composite photocatalyst Ni/TiO prepared in the example was weighed2/g-C3N4The device is used for researching the COS in the photocatalytic desorption simulation smoke under the ultraviolet lamp, and the simulation smoke is as follows: 0.1% of O2The concentration of COS inlet is 150ppm, the gas flow rate is 200mL/min, the wavelength of an ultraviolet lamp is 254nm, the reaction temperature is 30 ℃, the power of the ultraviolet lamp is 9W, and the model is TUV PL-S, Philips and Netherlands; the experimental results showed that the material prepared in this example had a COS removal efficiency of 85.7%.
Example 4: the method for adsorbing and photocatalytic purifying the organic sulfur in blast furnace gas by using the titanium dioxide-based material comprises the following specific steps:
(1) the procedure is as in example 1;
(2) the procedure is as in example 2;
(3) taking TiO2/g-C3N40.5g of binary composite catalyst is put into a triangular flask, and 20mL of 10% CuCl is added2After uniformly mixing the solution, placing the mixed suspension in an oil bath kettle at 90 ℃, heating and stirring for 1h, centrifuging at 8000rpm, and taking a precipitate; washing with deionized water and absolute ethyl alcohol alternately for 3 times, and vacuum drying at 60 deg.C for 24h to obtain ternary composite photocatalyst Cu/TiO2/g-C3N4；
And (3) detecting the catalytic performance: 0.1g of the ternary composite photocatalyst Cu/TiO prepared in the example was weighed2/g-C3N4The device is used for researching the COS in the photocatalytic desorption simulation smoke under the ultraviolet lamp, and the simulation smoke is as follows: 0.1% of O2The concentration of the COS inlet is 150ppm, the gas flow rate is 200mL/min, the wavelength of an ultraviolet lamp is 254nm, the reaction temperature is 30 ℃, the power of the ultraviolet lamp is 9W, and the model is TUV PL-S, Philips and Netherlands; the experimental results showed that the material prepared in this example had an efficiency of removing COS of 83.4%.
While the invention has been described in detail with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes in the form and details can be made therein without departing from the spirit and scope of the invention. However, the technology according to the present invention is intended to cover any simple modification, equivalent change and modification of the above embodiments without departing from the technical content of the present invention, and still fall within the protection scope of the technical solution of the present invention.
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