Gas phase sulphur foam flocculating precipitants and their use

Abstract

The application provides a gaseous sulfur foam flocculation precipitator and application thereof, and comprises at least one of mercaptan, thioether, ammonium sulfide, organic amine and carbon dioxide. The gaseous sulfur foam flocculation precipitator provided by the application is added in H2S gas, and the pressure is not higher than the saturated vapor pressure of each component, so that the sulfur foam can be rapidly agglomerated and large sulfur aggregation particles are formed in the process of generating the sulfur foam, and the sulfur aggregation particles are rapidly precipitated in the reaction process, thereby effectively avoiding the adhesion and blockage of the sulfur, avoiding the continuous cleaning of the reactor, and ensuring the stability of the device operation.

Description

Technical Field

[0001] This invention relates to the field of desulfurization technology, particularly in the areas of gas field purification, petroleum refining, and industrial waste gas treatment, belonging to the fields of resource utilization of harmful gases and large-scale hydrogen production from new energy sources. Specifically, it relates to a gaseous sulfur foam flocculant and precipitant and its application. Background Technology

[0002] Hydrogen sulfide is a harmful gas widely found in natural gas, shale gas, and fermentation plant vent gas. It not only causes significant environmental pollution but also seriously endangers human health, necessitating timely depletion after extraction. Currently, commonly used hydrogen sulfide treatment methods include Lockett.

[0003] The LO-CAT complex iron process and the Claus high-temperature oxidation method are among the methods used. The Claus process, in particular, is large-scale for H2S treatment and is commonly used for H2S removal in large gas fields. The process involves first oxidizing H2S-containing gas at high temperature in an oxidation reactor to produce a certain proportion of SO2. Then, the remaining H2S and SO2 (2:1) react to produce sulfur, which flows out of the reactor in liquid form. The molar ratio of H2S to SO2 must be strictly 2:1; otherwise, either H2S or SO2 will remain. Since H2S emissions are not permitted and must be completely oxidized to SO2, even after multiple post-treatment processes, the actual sulfide content emitted is still as high as 332 ppm, causing significant environmental pollution. Simultaneously, all the H in the H2S is discharged as H2O. Furthermore, a single Claus process requires a large footprint (2400 m²). 2 Furthermore, this requires a significant investment (approximately 150 million RMB for 3,000-5,000 tons of sulfur). Therefore, inventing a method that allows for the complete absorption of 100% H2S and the decomposition of H2S to produce H2 under mild reaction conditions, while simultaneously reducing the required land area and investment scale, would be of great strategic importance.

[0004] Our research team previously disclosed a method and apparatus for producing hydrogen and sulfur by decomposing hydrogen sulfide using a flow battery (CN 111232921A and CN114540827A). This method employs an electrochemical approach, utilizing redox ion pairs to reduce H₂S to sulfur and generate H₂. +Hydrogen is generated by hydrogen release, which is called off-site electrolytic hydrogen sulfide hydrogen and sulfur technology. In this process, sulfur is generated by H2S oxidation reactor. The sulfur particles generated in the H2S absorption removal process are small in diameter. Sulfur agglomeration is a quality control process, so it is not easy to precipitate, and the sulfur is floating on the surface of the desulfurization liquid, forming a large amount of sulfur foam. At the same time, this kind of sulfur is easy to adhere to the pipe wall, and the risk of sulfur plugging in the pipeline is large, and the equipment needs to be cleaned and repaired. Whether the sulfur can be precipitated and separated in time has become the key to the continuous and stable operation of the process. The types of sulfur flocculants reported in the patents are all for neutral and alkaline (pH = 6-11) conditions, such as CN114470885A, CN100438950C, etc. In the off-site electrolytic hydrogen sulfide hydrogen and sulfur technology developed by us, the H2S oxidation solution used is acidic (pH < 4), so it is urgent to develop a new structure type of sulfur foam flocculant suitable for acidic conditions, while not affecting the electrolysis efficiency and operation of the battery. In addition, in the previously reported patents of the research group, the sulfur foam flocculant is added to the absorption liquid, and a small amount of additive residue will be found in multiple cycles, which may have an impact on the battery structure in long-term operation. SUMMARY

[0005] The purpose of the present application is to provide a kind of acid condition under gas phase sulfur foam flocculation precipitator and its application.The gas phase sulfur foam flocculation precipitator provided by the present application is added in H2S gas, which is not higher than the saturated vapor pressure of each component, which can promote the rapid agglomeration of sulfur foam during the generation of sulfur foam, form larger sulfur aggregate particles, and quickly precipitate during the reaction process, which can effectively avoid sulfur adhesion and plugging, and avoid continuous cleaning of the reactor, to ensure the stability of the device operation.In addition, the H2S oxidation solution needs to be regenerated in the electrolytic cell after removing the sulfur precipitate, so the residual in the solution should not affect the electrolysis process, so the simple component is the desired of the present application.

[0006] According to the first aspect of the present application, a gas phase sulfur foam flocculation precipitator is provided, comprising at least one of mercaptan, sulfide, sulfamide, organic amine and carbon dioxide.

[0007] Optionally, the gas phase sulfur foam flocculation precipitator consists of at least one of mercaptan, sulfide, sulfamide, organic amine and carbon dioxide.

[0008] Optionally, the organic amine is selected from at least one of primary amine, secondary amine and tertiary amine.

[0009] Optionally, the mercaptan is C1-C6 mercaptan.

[0010] The sulfide is C1-C8 sulfide.

[0011] The sulfamide is C1-C6 sulfamide.

[0012] The organic amine is a C1-C 10 organic amine.

[0013] Optionally, the thiol is selected from a monovalent thiol or a multivalent thiol, wherein the multivalent is greater than or equal to 2; the organic amine is selected from a monovalent organic amine or a multivalent organic amine.

[0014] Optionally, the thiol is selected from at least one of methyl mercaptan, ethyl mercaptan, ethanedithiol, 1-propanethiol, 1,3-propanedithiol, 1-hexanethiol;

[0015] The sulfide is selected from at least one of methyl sulfide, ethyl sulfide, diallyl sulfide;

[0016] The sulfide is selected from at least one of methyl sulfide, ethyl sulfide, diallyl sulfide;

[0017] The organic amine is selected from at least one of methanolamine, ethanolamine, diethanolamine, N-methyl diethanolamine.

[0018] According to a second aspect of the present application, there is provided an application of the above-mentioned gaseous sulfur foam flocculation precipitator in acid removal of hydrogen sulfide, wherein the gaseous sulfur foam flocculation precipitator and the acid H2S gas are mixed, the absorption liquid is added into the reactor, and the H2S gas source containing the gaseous sulfur foam flocculation precipitator is introduced into the reactor;

[0019] The gaseous sulfur foam flocculation precipitator is selected from the above-mentioned gaseous sulfur foam flocculation precipitator.

[0020] Optionally, the absorption liquid includes one or more of I3 - , Br2, Fe 3+ , VO 2+ .

[0021] Optionally, after the I3 - in the absorption liquid reacts with H2S, I - is obtained; after Br2 reacts with H2S, Br - is obtained; after Fe 3+ reacts with H2S, Fe 2+ is obtained; after VO 2+ reacts with H2S, VO2 + is obtained.

[0022] Preferably, the absorption liquid further includes an acid compound.

[0023] Further preferably, the volume content of the gaseous phase sulfur bubble flocculation precipitator in the H2S gas source is 1 ppm to 1000000 ppm; the gaseous phase sulfur bubble flocculation precipitator is selected from at least one of sulfide, mercaptan, ammonium sulfide, organic amine; and / or,

[0024] The mass content of the gaseous phase sulfur bubble flocculation precipitator in the H2S gas source is 0.0001% to 50%;

[0025] The gaseous phase sulfur bubble flocculation precipitator is selected from carbon dioxide.

[0026] Optionally, the working pH value range of the gaseous phase sulfur bubble flocculation precipitator is -1 to 5.

[0027] Optionally, the upper limit of the working pH value of the gaseous phase sulfur bubble flocculation precipitator is independently selected from 5, 4, 3, 2, 1, 0; the lower limit is independently selected from -1, 4, 3, 2, 1, 0.

[0028] Optionally, the working temperature of the gaseous phase sulfur bubble flocculation precipitator is 10 to 120℃.

[0029] Optionally, the upper limit of the working temperature of the gaseous phase sulfur bubble flocculation precipitator is independently selected from 120℃, 100℃, 80℃, 60℃, 40℃, 25℃, and the lower limit is independently selected from 10℃, 100℃, 80℃, 60℃, 40℃, 25℃.

[0030] Optionally, the reactor is selected from any one of packed column type, kettle type, slurry bed type, preferably a kettle type reactor.

[0031] The method of the present application can obtain the following beneficial effects:

[0032] The present application uses components such as mercaptan, sulfide, ammonium sulfide, organic amine, and gas CO2. For sulfides such as mercaptan, sulfide, and ammonium sulfide, these components will be adsorbed to the surface of sulfur particles, and through these components, the generated sulfur particle adhesion agglomeration will be promoted to facilitate precipitation. For organic amine, it will bond with the negative charge sulfur functional group adsorbed to the surface of sulfur particles, eliminate electrostatic repulsion, and promote sulfur particle precipitation. And for gas components, it will promote the desorption of adsorbed sulfur-containing functional groups, eliminate electrostatic repulsion, and promote sulfur particle precipitation. These three different principles can all promote sulfur particle precipitation. The results of the examples show that after the absorbent of the absorption liquid is completely consumed, the sulfur particles are also basically precipitated to the bottom of the absorber, which is easy to analyze by centrifugation, and there is no obvious sulfur adsorption on the wall of the reactor. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1Optical contrast photos of no addition in Example 1, addition of ethanethiol in Example 1, and addition of N-methyldiethanolamine sulfur flocculating precipitator in Example 4;

[0034] Figure 2 XRD pattern of sulfur obtained under the condition No. 1 in Example 1. DETAILED DESCRIPTION

[0035] The present application will be described in detail below with reference to examples, but the present application is not limited to these examples.

[0036] The analysis method in the examples of the present application is as follows:

[0037] Analysis method: In the present application, the concentration change of the absorbed substance in the solution is tested by a potentiometric titrator; the consumption of H2S is determined by recording the pressure change of the reactor, and the sulfur precipitation rate is calculated by weighing the mass of the floated and precipitated sulfur;

[0038] In the present application, the concentration change of the absorbed substance in the solution is preferably tested by a potentiometric titrator, and then the reaction rate is calculated;

[0039] A centrifuge is used to separate the upper and lower sulfur, and after being washed clean, the powder sulfur particles are obtained by drying;

[0040] In the examples of the present application, the sulfur precipitation rate is defined as:

[0041] The mass percentage of the lower precipitated sulfur in the total collected sulfur, i.e.,

[0042] D% = m 下层 / m 总 × 100%

[0043] D is the precipitation rate, m is the mass, and lower represents the lower precipitated sulfur.

[0044] In the examples of the present application, the conversion rate of the absorbed substance is calculated according to the formula:

[0045] Taking Fe 3+ salt as the absorbed substance as an example, then:

[0046] Fe 3+ conversion rate = [n(Fe 2+ ) / (n(Fe 2+ )+n(Fe 3+ )] × 100%;

[0047] n = the molar amount of trivalent iron or divalent iron.

[0048] In the examples of the present application, the sulfur recovery rate is defined as:

[0049] S recovery rate = [(m 上层 +m下层 ) / m 理论 ]×100%;

[0050] Example 1

[0051] Effect of C1 to C6 mercaptans on the precipitation rate of sulfur

[0052] The specific experimental procedure is as follows: 20 mL of Fe2(SO4)3solution with a concentration of 0.5 M and a supporting acid of sulfuric acid is added to a stainless steel reactor with a polytetrafluoroethylene lining, and the total volume is 52 mL. The reactor is sealed, and a pressure test is performed to ensure that the seal is good, and then a certain pressure of 100% H2S is injected. Then, stirring is performed at 25°C until the reaction is complete, and Fe 3+ is completely converted. This experiment is used as a blank control experiment. Then, methyl mercaptan, ethyl mercaptan, ethanedithiol, 1-propanethiol, 1,3-propanedithiol, and 1-hexanethiol are sequentially mixed into H2S, with the amount of injection being 5 ppm to 100,000 ppm of the total volume of H2S (determined by the saturated vapor pressure), while ensuring that the other conditions are the same. Under these conditions, the working pH of the reaction is between -0.5 and 0. The optimal experimental results under the reaction conditions are shown in Table 1.

[0053] Figure 1 The optical contrast photos for Example 1 without the addition of ethyl mercaptan and with the addition of ethyl mercaptan are shown in the figure. As can be seen from the figure, after the addition of ethyl mercaptan, the sulfur is obviously precipitated to the bottom, and the supernatant is on top and the precipitate is at the bottom. The XRD pattern of the sulfur obtained under condition No. 1 is shown in Figure 2 .

[0054] Table 1. Effect of C1 to C6 mercaptans on the precipitation rate of sulfur

[0055]

[0056]

[0057] Example 2

[0058] Effect of sulfides on the precipitation rate of sulfur

[0059] The specific experimental procedure is as follows: 20 mL of Fe2(SO4)3solution with a concentration of 0.5 M and a supporting acid of sulfuric acid is added to a stainless steel reactor with a polytetrafluoroethylene lining, and the total volume is 52 mL. The reactor is sealed, and a pressure test is performed to ensure that the seal is good, and then a certain pressure of 100% H2S is injected. Then, stirring is performed at 25°C until the reaction is complete, and Fe 3+The experiment was carried out as a blank control. Then, dimethyl sulfide, diethyl sulfide, diallyl sulfide and the like were mixed into H2S in turn, and the amount of the mixture was 5 ppm to 100,000 ppm of the total volume of H2S (determined by the saturated vapor pressure). Under this condition, the working pH of the reaction was between -0.5 and 0. The optimal experimental results under the reaction conditions are shown in Table 2.

[0060] Table 2. Effect of sulfide on the precipitation rate of sulfur

[0061]

[0062] Example 3

[0063] Effect of thiamine on the precipitation rate of sulfur

[0064] The specific experimental steps are as follows: 20 mL of Fe2(SO4)3 solution with a concentration of 0.5 M and sulfuric acid as the supporting acid was added to a stainless steel reaction kettle with polytetrafluoroethylene as the inner lining, and the total volume was 52 mL. The reaction kettle was sealed, and the pressure was tested for leaks to ensure good sealing. Then, 100% H2S was injected at a certain pressure. Subsequently, stirring was carried out at 25°C until the reaction was completed, and the Fe 3+ The experiment was carried out as a blank control. Then, dimethyl sulfide, diethyl sulfide, diallyl sulfide and the like were mixed into H2S in turn, and the amount of the mixture was 5 ppm to 100,000 ppm of the total volume of H2S (determined by the saturated vapor pressure). Under this condition, the working pH of the reaction was between -0.5 and 0. The optimal experimental results under the reaction conditions are shown in Table 2.

[0065] Table 3. Effect of thiamine on the precipitation rate of sulfur

[0066]

[0067] Example 4

[0068] Effect of organic amine on the precipitation rate of sulfur

[0069] The specific experimental steps are as follows: 20 mL of Fe2(SO4)3 solution with a concentration of 0.5 M and sulfuric acid as the supporting acid was added to a stainless steel reaction kettle with polytetrafluoroethylene as the inner lining, and the total volume was 52 mL. The reaction kettle was sealed, and the pressure was tested for leaks to ensure good sealing. Then, 100% H2S was injected at a certain pressure. Subsequently, stirring was carried out at 25°C until the reaction was completed, and the Fe 3+The experiment was carried out as a blank control experiment. Then, methanol amine, ethanol amine, diethanol amine, N-methyl diethanol amine and the like were sequentially mixed into H2S, and the input amount was 5 ppm to 6612 ppm (determined by the saturated vapor pressure) of the total volume of H2S. At the same time, other conditions were ensured to be the same. Under this condition, the working pH of the reaction was between -0.5 and 0. The optimal experimental results under the reaction conditions are shown in Table 4. Figure 1 For the optical comparison photos without adding organic amine and adding N-methyl diethanol amine sulfur flocculation precipitant, it can be seen from the figure that sulfur is obviously precipitated to the bottom.

[0070] Table 4. Influence of organic amine content on sulfur precipitation rate

[0071]

[0072]

[0073] Example 5

[0074] Influence of CO2 content on sulfur precipitation rate

[0075] The specific experimental steps are as follows: 20 mL of Fe2(SO4)3 solution with a concentration of 0.5 M and supported acid of sulfuric acid was added to a stainless steel reaction kettle with polytetrafluoroethylene as the inner lining, and the total volume was 52 mL. The reaction kettle was sealed, and the pressure was tested for leakage to ensure good sealing. Then, a certain pressure of 100% H2S was injected. Then, stirring was carried out at 25°C until the reaction was completed, and Fe 3+ The experiment was carried out as a blank control experiment. Then, H2S mixed gas containing 1%, 10%, 30%, and 50% CO2 by volume was sequentially introduced into the kettle. At the same time, other conditions were ensured to be the same. Under this condition, the working pH of the reaction was between -0.5 and 0. The optimal experimental results under the experimental conditions are shown in Table 5.

[0076] Table 5. Influence of CO2 content on sulfur precipitation rate

[0077]

[0078] Example 6

[0079] Influence of mercaptan on sulfur precipitation rate

[0080] The specific experimental steps are as follows: 20 mL of I3 - solution with a concentration of 0.5 M and supported acid of sulfuric acid was added to a stainless steel reaction kettle with polytetrafluoroethylene as the inner lining, and the total volume was 52 mL. The reaction kettle was sealed, and the pressure was tested for leakage to ensure good sealing. Then, a certain pressure of 100% H2S was injected. Then, stirring was carried out at 25°C until the reaction was completed, and I3 -The experiment results are used as blank control experiment. Then, methyl mercaptan, ethyl mercaptan, ethanedithiol, 1-propanethiol, 1, 3-propanedithiol, 1-hexanethiol and the like are mixed into H2S in turn, the input amount is 5 ppm to 100000 ppm of the total volume of H2S (determined by saturated vapor pressure), while ensuring that other conditions are the same. Under this condition, the working pH of the reaction is between -0.5 and 0. The optimal experimental results under the reaction conditions are shown in Table 6.

[0081] Table 6. Influence of mercaptan on the precipitation rate of sulfur

[0082]

[0083] Example 7

[0084] Influence of organic amine on the precipitation rate of sulfur

[0085] The specific experimental steps are as follows: 20 mL I3 - solution with a concentration of 0.5 M and sulfuric acid as supporting acid is added to a stainless steel reaction kettle with polytetrafluoroethylene as inner lining, and the total volume is 52 mL. The reaction kettle is sealed, and the pressure is tested for leakage to ensure good sealing. Then, a certain pressure of 100% H2S is injected. Then, stirring is carried out at 25°C until the reaction is completed, and I3 - The experiment results are used as blank control experiment. Then, methyl mercaptan, ethyl mercaptan, ethanedithiol, 1-propanethiol, 1, 3-propanedithiol, 1-hexanethiol and the like are mixed into H2S in turn, the input amount is 5 ppm to 100000 ppm of the total volume of H2S (determined by saturated vapor pressure), while ensuring that other conditions are the same. Under this condition, the working pH of the reaction is between -0.5 and 0. The optimal experimental results under the reaction conditions are shown in Table 6.

[0086] Table 7. Influence of organic amine on the precipitation rate of sulfur

[0087]

[0088] The above is only a few embodiments of the present application, and does not limit the present application in any form. Although the above preferred embodiments are disclosed, they are not intended to limit the present application. Any skilled person in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the technical solution of the present application, which are equivalent to equivalent embodiments, and are within the scope of the technical solution.

Claims

1. The application of a gaseous sulfur foam flocculant in the acidic removal of hydrogen sulfide, characterized in that, The gaseous sulfur foam flocculant and precipitant is mixed with acidic H2S gas, the absorbent is added to the reactor, and the reactor is then fed with H2S gas containing the gaseous sulfur foam flocculant. The gaseous sulfur foam flocculant includes at least one of thiols, thioethers, thioamines, organic amines, and carbon dioxide. The organic amine is selected from at least one of methanolamine, ethanolamine, diethanolamine, and N-methyldiethanolamine; The absorbent liquid contains I3 - Br2, Fe 3+ VO 2+ One or more of these, and acid compounds; The working pH range of the gas-phase sulfur foam flocculant is -1 to 5; When the gaseous sulfur foam flocculant is selected from at least one of mercaptans, thioethers, thioamines, and organic amines, the volume content of the gaseous sulfur foam flocculant in the H2S gas source is from 1 ppm to 1,000,000 ppm. When the gaseous sulfur foam flocculant is selected from carbon dioxide, the mass content of the gaseous sulfur foam flocculant in the H2S gas source is 0.0001% to 50%.

2. The application according to claim 1, characterized in that, The thiol is a C1-C6 thiol; The sulfide is a C1-C8 sulfide; The thiamine is a C1-C6 thiamine.

3. The application according to claim 1, characterized in that, The thiol is selected from at least one of methanethiol, ethanethiol, ethylenedithiol, 1-propanethiol, 1,3-propanedithiol, and 1-hexanethiol; The sulfide is selected from at least one of methyl sulfide, ethyl sulfide, and diallyl sulfide; The thiamine is selected from at least one of 2-mercaptoethylamine, cysteine, and 2-mercaptoaniline.

4. The application according to claim 1, characterized in that, The working temperature of the gas-phase sulfur foam flocculant is 10~120℃.

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