Method for reducing the degradation of iron-based ionic liquids in the catalytic oxidation of hydrogen sulfide

Abstract

The invention discloses a method for reducing the degradation of iron-based ionic liquids in the process of catalytic oxidation of hydrogen sulfide. The initial water content of iron-based ionic liquids is reduced, and the reaction temperature and / or the flow rate of oxygen supply gas are increased to remove moisture in the reaction process. , reduce the water content of the ionic liquid in the reaction process, thereby reducing the degradation of organic cations in the ionic liquid, and solve the problem of ferrous ions in the presence of water and oxygen in the process of catalytic oxidation of hydrogen sulfide by [bmim]Fe(III)Cl4 ionic liquid OH radicals are generated to oxidize organic cations, leading to the degradation of iron-based ionic liquids in the catalytic oxidation of hydrogen sulfide. The method is simple and easy to operate, and effectively reduces the degradation of the iron-based ionic liquid in the catalytic oxidation of hydrogen sulfide.

Description

technical field

[0001] The invention relates to the field of liquid-phase catalytic oxidation of hydrogen sulfide, in particular to a method for reducing the degradation of iron-based ionic liquids in the process of catalytic oxidation of hydrogen sulfide. Background technique

[0002] 1-Butyl-3-methylimidazolium tetrachloroferrate ([bmim]Fe(III)Cl 4 ) The process of ionic liquid catalysis-oxidation hydrogen sulfide is: [bmim]Fe(III)Cl 4 First react with hydrogen sulfide gas to generate sulfur and 1-butyl-3-methylimidazolium hydroferrous tetrachloride ([bmim]Fe(II)Cl 4 H) ionic liquid, and then oxygen oxidizes ferrous tetrachloride ionic liquid to regenerate [bmim]Fe(III)Cl 4 and water. In this process, [bmim]Fe(III)Cl 4 The ionic liquid is the catalyst, the oxygen is the oxidant, and the products are sulfur and water. Sulfur can be recovered by filtration. while [bmim]Fe(III)Cl 4 is hydrophobic, theoretically, [bmim]Fe(III)Cl 4 Two phases should be formed with water...

Examples

Embodiment 1

[0035] This embodiment provides a method for reducing the degradation of iron-based ionic liquids in the liquid-phase catalytic oxidation of hydrogen sulfide, from which, it can be determined that the water content of iron-based ionic liquids reacts to [bmim] + The impact of degradation rate, the steps are as follows:

[0036] FeCl 3 ·6H 2 O and [bmim]Cl were mixed in molar ratios of 0.1:1, 0.2:1, 0.3:1, 0.4:1, and 0.5:1, respectively, and stirred in an open environment at 40°C until a homogeneous solution was formed. The resulting solution was rotary evaporated at 60°C, and vacuum-dried at 80°C for 12 hours to obtain an iron-based ionic liquid with a molar ratio of less than 1:1;

[0037] FeCl 3 ·6H 2 O and [bmim]Cl were mixed at a molar ratio of 2:1, stirred at room temperature for 24 hours, and separated into layers. After taking the upper liquid, the resulting solution was rotary evaporated at 60°C and vacuum-dried at 80°C for 12 hours. Get [bmim]FeCl 4 ionic liquid;...

Embodiment 2

[0043] This embodiment provides a method for reducing the degradation of iron-based ionic liquids in the liquid-phase catalytic oxidation of hydrogen sulfide, from which the initial moisture content to [bmim] can be determined + The impact of degradation rate, the steps are as follows:

[0044] FeCl 3 ·6H 2 O and [bmim]Cl were mixed at a molar ratio of 0.4:1 and stirred in an open environment at 40°C until a homogeneous solution was formed, then the resulting solution was rotary evaporated at 60°C and dried under vacuum at 80°C for 12 hours An iron-based ionic liquid with a water content of 0.6% was obtained;

[0045] FeCl 3 ·6H 2 After mixing O and [bmim]Cl according to a molar ratio of 0.4:1, stirring in an open environment at 40°C until a homogeneous solution is formed, an iron-based ionic liquid with a water content of 11.07% is obtained;

[0046] use figure 2 In the shown reaction device, 40 mL of iron-based ionic liquid was injected into a three-necked flask, and ...

Embodiment 3

[0048] This embodiment provides a method for reducing the degradation of iron-based ionic liquids in the liquid-phase catalytic oxidation of hydrogen sulfide, from which, it is possible to determine the effect of temperature on [bmim] + The impact of degradation rate, the steps are as follows:

[0049] FeCl 3 ·6H 2 O and [bmim]Cl were mixed at a molar ratio of 2:1, stirred at room temperature for 24 h, and separated into layers. After taking the upper liquid, the resulting solution was rotary evaporated at 60°C, and vacuum-dried at 80°C for 12 hours to get [bmim]FeCl 4 ionic liquid.

[0050] Take 33mL of iron-based ionic liquid with a molar ratio of 2:1 and inject figure 1 In a three-necked flask, at 25°C and 80°C, O with a purity of 99.9% was controlled 2 The flow rate is 20mL / min, the purity of 99.9% H 2 The flow rate of S is 20mL / min, and the UV-2450 ultraviolet-visible light analyzer is used to measure [bmim] in the catalytic oxidation system every hour + concentrat...

technical field

[0001] The invention relates to the field of liquid-phase catalytic oxidation of hydrogen sulfide, in particular to a method for reducing the degradation of iron-based ionic liquids in the process of catalytic oxidation of hydrogen sulfide. Background technique

[0002] 1-Butyl-3-methylimidazolium tetrachloroferrate ([bmim]Fe(III)Cl 4 ) The process of ionic liquid catalysis-oxidation hydrogen sulfide is: [bmim]Fe(III)Cl 4 First react with hydrogen sulfide gas to generate sulfur and 1-butyl-3-methylimidazolium hydroferrous tetrachloride ([bmim]Fe(II)Cl 4 H) ionic liquid, and then oxygen oxidizes ferrous tetrachloride ionic liquid to regenerate [bmim]Fe(III)Cl 4 and water. In this process, [bmim]Fe(III)Cl 4 The ionic liquid is the catalyst, the oxygen is the oxidant, and the products are sulfur and water. Sulfur can be recovered by filtration. while [bmim]Fe(III)Cl 4 is hydrophobic, theoretically, [bmim]Fe(III)Cl 4 Two phases should be formed with water...

Examples

Embodiment 1

[0035] This embodiment provides a method for reducing the degradation of iron-based ionic liquids in the liquid-phase catalytic oxidation of hydrogen sulfide, from which, it can be determined that the water content of iron-based ionic liquids reacts to [bmim] + The impact of degradation rate, the steps are as follows:

[0036] FeCl 3 ·6H 2 O and [bmim]Cl were mixed in molar ratios of 0.1:1, 0.2:1, 0.3:1, 0.4:1, and 0.5:1, respectively, and stirred in an open environment at 40°C until a homogeneous solution was formed. The resulting solution was rotary evaporated at 60°C, and vacuum-dried at 80°C for 12 hours to obtain an iron-based ionic liquid with a molar ratio of less than 1:1;

[0037] FeCl 3 ·6H 2 O and [bmim]Cl were mixed at a molar ratio of 2:1, stirred at room temperature for 24 hours, and separated into layers. After taking the upper liquid, the resulting solution was rotary evaporated at 60°C and vacuum-dried at 80°C for 12 hours. Get [bmim]FeCl 4 ionic liquid;...

Embodiment 2

[0043] This embodiment provides a method for reducing the degradation of iron-based ionic liquids in the liquid-phase catalytic oxidation of hydrogen sulfide, from which the initial moisture content to [bmim] can be determined + The impact of degradation rate, the steps are as follows:

[0044] FeCl 3 ·6H 2 O and [bmim]Cl were mixed at a molar ratio of 0.4:1 and stirred in an open environment at 40°C until a homogeneous solution was formed, then the resulting solution was rotary evaporated at 60°C and dried under vacuum at 80°C for 12 hours An iron-based ionic liquid with a water content of 0.6% was obtained;

[0045] FeCl 3 ·6H 2 After mixing O and [bmim]Cl according to a molar ratio of 0.4:1, stirring in an open environment at 40°C until a homogeneous solution is formed, an iron-based ionic liquid with a water content of 11.07% is obtained;

[0046] use figure 2 In the shown reaction device, 40 mL of iron-based ionic liquid was injected into a three-necked flask, and ...

Embodiment 3

[0048] This embodiment provides a method for reducing the degradation of iron-based ionic liquids in the liquid-phase catalytic oxidation of hydrogen sulfide, from which, it is possible to determine the effect of temperature on [bmim] + The impact of degradation rate, the steps are as follows:

[0049] FeCl 3 ·6H 2 O and [bmim]Cl were mixed at a molar ratio of 2:1, stirred at room temperature for 24 h, and separated into layers. After taking the upper liquid, the resulting solution was rotary evaporated at 60°C, and vacuum-dried at 80°C for 12 hours to get [bmim]FeCl 4 ionic liquid.

[0050] Take 33mL of iron-based ionic liquid with a molar ratio of 2:1 and inject figure 1 In a three-necked flask, at 25°C and 80°C, O with a purity of 99.9% was controlled 2 The flow rate is 20mL / min, the purity of 99.9% H 2 The flow rate of S is 20mL / min, and the UV-2450 ultraviolet-visible light analyzer is used to measure [bmim] in the catalytic oxidation system every hour + concentrat...

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