Desulfurization method for hydrogen sulfide absorption liquid in laboratory
By using a combination of complexed iron solution and oxidizing gas in the laboratory, the problem of difficult treatment of hydrogen sulfide absorbent was solved, achieving efficient sulfur recovery and low-emission hydrogen sulfide treatment.
Patent Information
- Application Number
- CN202511017236.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-23
- Publication Date
- 2025-10-31
AI Technical Summary
The inability to effectively centrally treat hydrogen sulfide absorption liquid in the laboratory leads to a persistent odor problem.
The method involves combining a complexed iron solution with an oxidizing gas. This is achieved by adding an iron complex of EDTA, a hydroxy aldehyde, a hydroxycarboxylic acid compound, and a surfactant complexed iron solution to a hydrogen sulfide absorbent, and using compressed air, oxygen, or ozone as the oxidizing gas to carry out an oxidation reaction to generate elemental sulfur.
It achieves high sulfur recovery rate and low hydrogen sulfide emissions, is easy to operate, and reduces the malodorous emissions of hydrogen sulfide in the laboratory.
Smart Images
Figure CN120860772A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of laboratory desulfurization technology, and particularly relates to a method for desulfurizing laboratory hydrogen sulfide absorption liquid. Background Technology
[0002] hydrogen sulfide Hydrogen sulfide, a highly toxic and corrosive gas, is both an important raw material and a hazardous pollutant in chemical production and laboratory research. The recovery and resource utilization of hydrogen sulfide has become an unavoidable issue in modern chemical industry and laboratory research. This colorless gas, with a strong rotten egg odor, is denser than air, readily soluble in water to form a weakly acidic solution, and is extremely toxic. Therefore, the effective control and treatment of hydrogen sulfide, whether on an industrial or laboratory scale, is crucial for personnel safety, environmental protection, and resource utilization.
[0003] In the industrial sector, traditional methods for treating hydrogen sulfide, such as the Claus process, involve partially burning hydrogen sulfide to generate sulfur dioxide, which is then reacted with the remaining hydrogen sulfide under the action of a catalyst to generate elemental sulfur. The sulfur recovery rate can reach 95-98%, and this process has become the standard configuration in the petroleum refining industry.
[0004] In laboratory environments, hydrogen sulfide primarily originates as a byproduct of chemical synthesis reactions, especially in the synthesis of thiol compounds such as tert-dodecyl mercaptan, n-dodecyl mercaptan, tetrahydrothiophene, 2-mercaptoethanol, and 3-mercaptopropionic acid. In these processes, hydrogen sulfide often appears as a reactant or byproduct. Unlike industrial environments, laboratory-generated hydrogen sulfide is characterized by small, discontinuous amounts and large concentration fluctuations. Laboratories typically use alkaline absorption to treat excess hydrogen sulfide, converting it into compounds like sodium hydrosulfide for temporary storage. However, this absorbent gradually releases hydrogen sulfide gas, producing a persistent odor. Furthermore, due to the intermittent nature of laboratory operations, the absorbent cannot reach high saturation levels for centralized treatment like in industrial settings, creating unique laboratory-specific treatment challenges. Summary of the Invention
[0005] To address the problem of the inability to centrally process small amounts of hydrogen sulfide gas during laboratory alkaline absorption, which easily leads to persistent and difficult-to-eliminate odors, this invention provides a desulfurization method for laboratory hydrogen sulfide absorption liquid.
[0006] The technical solution of the present invention:
[0007] A desulfurization method for a laboratory hydrogen sulfide absorbent solution involves adding the hydrogen sulfide absorbent solution to a complexed iron solution, and then introducing an oxidizing gas into the resulting desulfurization system for oxidation to obtain elemental sulfur. The complexed iron solution contains the following components at mass concentrations: 4-15% EDTA iron complex, 0.5-3% hydroxy aldehyde, 0-1% hydroxycarboxylic acid compound, 0.3-0.5% surfactant, and 0.1-0.3% ultralight silica gel. The oxidizing gas is compressed air, oxygen, or ozone oxidation.
[0008] Furthermore, the hydrogen sulfide absorbing solution is an organic amine solution or an inorganic alkaline solution that has absorbed hydrogen sulfide.
[0009] Furthermore, the organic amine solution is an aqueous solution of N-methyldiethanolamine, and the concentration of the aqueous solution of N-methyldiethanolamine is 30-40%; the inorganic alkaline solution is absorbed by an aqueous solution of Na2CO3 or NaOH, and the concentration of the aqueous solution of Na2CO3 is 15% and the concentration of the aqueous solution of NaOH is 30%.
[0010] Furthermore, the iron complex of EDTA is sodium iron salt of EDTA, or a mixture of iron salt and EDTA, or a mixture of iron salt and disodium EDTA, or a mixture of sodium iron salt of EDTA and disodium EDTA, wherein the EDTA or disodium EDTA is used in excess.
[0011] Furthermore, the iron salt is ferrous sulfate, ferric sulfate, ferric chloride, ferric ammonium sulfate, or ferrous ammonium sulfate; the hydroxy aldehyde is glucose; the hydroxy carboxylic acid compound is oxalic acid, citric acid, lactic acid, tartaric acid, salicylic acid, or sulfosalicylic acid; and the surfactant is polyacrylamide, polypyrrolidone, polyethylene glycol, or polypropylene glycol.
[0012] Furthermore, the pH of the complexed iron solution is adjusted to 7 using a saturated KOH aqueous solution.
[0013] Furthermore, the oxidizing gas enters the desulfurization system through a stainless steel sintered filter, and the oxidizing gas is circulated in the desulfurization system by a diaphragm pump. Excess gas is absorbed by alkaline solution and then discharged.
[0014] Furthermore, the flow rate of the oxidizing gas entering the desulfurization system is 200~500 ml / min, and the flow rate of the oxidizing gas circulated by the diaphragm pump is 50 ml / min.
[0015] Furthermore, the hydrogen sulfide absorbent is added to the complexed iron solution in batches. After oxidation is completed, a small amount of acid is added to the desulfurization system to maintain the pH value of the system between 6.0 and 9.0.
[0016] Furthermore, each time 10 ml of hydrogen sulfide absorbent is added to the complexed iron solution, concentrated hydrochloric acid is added dropwise after 5 minutes to adjust the pH of the desulfurization system to 7 before adding the next batch of hydrogen sulfide absorbent.
[0017] The beneficial effects of this invention are:
[0018] The desulfurization method for laboratory hydrogen sulfide absorption liquid provided by this invention has the advantages of high sulfur recovery rate, low hydrogen sulfide emission, and simple operation. The complexed iron solution used in this desulfurization method uses EDTA iron complexes as the main component. The addition of hydroxyaldehydes and hydroxycarboxylic acids as multi-component complexes further enhances the stability of the complexed iron. Adjusting the pH to 7 with KOH aqueous solution facilitates the oxidation process. Adding surfactants improves the dispersion of oxidizing gas in the desulfurization system and increases the size of the oxidized elemental sulfur particles. Adding ultralight silica gel facilitates the adsorption of elemental sulfur onto the silica gel, forming larger particles. The circulation of oxidizing gas in the desulfurization system reduces hydrogen sulfide overflow during oxidation, thus reducing hydrogen sulfide emissions. Using ozone as the oxidizing gas accelerates the oxidation rate and improves desulfurization efficiency. Attached Figure Description
[0019] Figure 1 The infrared spectrum of elemental sulfur obtained from the desulfurization treatment in Example 4 is shown. Detailed Implementation
[0020] The technical solution of the present invention will be further described below with reference to embodiments, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention. In the following embodiments, the process equipment or apparatus not specifically specified are all conventional equipment or apparatus in the art. Unless otherwise specified, the raw materials used in the embodiments of the present invention are all commercially available; unless otherwise specified, the technical means used in the embodiments of the present invention are all conventional means well known to those skilled in the art.
[0021] Example 1
[0022] This embodiment provides a method for desulfurizing a laboratory hydrogen sulfide absorption solution.
[0023] In this embodiment, hydrogen sulfide from the tail gas generated during the synthesis of organic sulfur compounds such as tert-dodecyl mercaptan, n-dodecyl mercaptan, 3-mercaptopropionic acid, and tetrahydrothiophene is absorbed by a 30% NaOH aqueous solution to obtain hydrogen sulfide NaOH absorption solution A.
[0024] In a 1 L three-necked flask equipped with a magnetic stirrer, add 18.35 g of sodium EDTA iron, 8.41 g of disodium EDTA, 4.5 g of glucose, 4.80 g of tartaric acid, 2.0 g of polypropylene glycol 600, and 1.4 g of ultralight silica gel, then add 600 ml of water. After thorough dispersion, adjust the pH to 7 using saturated KOH to obtain complexed iron solution A.
[0025] Air enters the complexed iron solution A through a stainless steel sintered filter at a flow rate of 250 ml / min. 10 ml of hydrogen sulfide NaOH absorbent solution A is added to the complexed iron solution B each time. After 5 minutes of adding the absorbent solution, concentrated hydrochloric acid is added dropwise until the pH of the solution reaches approximately 7. A total of 400 ml of hydrogen sulfide NaOH absorbent solution B is added, yielding 16.42 g of yellow sulfur containing SiO2.
[0026] Example 2
[0027] This embodiment provides a method for desulfurizing a laboratory hydrogen sulfide absorption solution.
[0028] In this embodiment, hydrogen sulfide from the tail gas generated during the synthesis of organic sulfur compounds such as tert-dodecyl mercaptan, n-dodecyl mercaptan, 3-mercaptopropionic acid, and tetrahydrothiophene is absorbed by a 30% N-methyldiethanolamine (MEDA) aqueous solution to obtain hydrogen sulfide MEDA absorbent solution B.
[0029] In a 5 L three-necked flask equipped with a magnetic stirrer, add 27.81 g of ferrous sulfate heptahydrate (FeSO4·7H2O), 33.6 g of disodium EDTA, 18.0 g of glucose, 2.0 g of polypropylene glycol 600, and 1.0 g of ultralight silica gel, then add 600 ml of water. After thorough dissolution and dispersion, adjust the pH to 7 using a saturated KOH aqueous solution to obtain complexed iron solution B.
[0030] Oxygen enters the complexed iron solution C through a stainless steel sintered filter at a flow rate of 500 ml / min. The oxygen in the reaction system is circulated by a diaphragm pump, and the oxygen flow rate can be reduced to 50 ml / min during circulation. Excess gas is absorbed by alkaline solution and then discharged.
[0031] The complexed iron solution B was heated to 30°C. 2000 ml of hydrogen sulfide MEDA absorbent solution B was added over 6 hours. After the addition was complete, stirring was continued and oxygen was introduced for 1 hour. The mixture was then filtered to obtain 46.72 g of yellowish-gray sulfur.
[0032] Example 3
[0033] This embodiment provides a method for desulfurizing a laboratory hydrogen sulfide absorption solution.
[0034] In this embodiment, hydrogen sulfide from the tail gas generated during the synthesis of organic sulfur compounds such as tert-dodecyl mercaptan, n-dodecyl mercaptan, 3-mercaptopropionic acid, and tetrahydrothiophene is absorbed by a 40% N-methyldiethanolamine (MEDA) aqueous solution to obtain hydrogen sulfide MEDA absorbent solution C.
[0035] In a 5 L three-necked flask equipped with a magnetic stirrer, add 38.58 g of ferric ammonium sulfate dodecahydrate (Fe(NH4)SO4·12H2O), 7.84 g of ferrous ammonium sulfate heptahydrate (Fe(NH4)2SO4·7H2O), 40.35 g of disodium EDTA, 9.0 g of glucose, 2.0 g of polypropylene glycol 400, and 1.0 g of ultralight silica gel, then add 600 ml of water. After thorough dissolution and dispersion, adjust the pH to 7 using a saturated KOH aqueous solution to obtain complexed iron solution C.
[0036] Oxygen passes through an ozone generator and a stainless steel sintered filter before entering the complexed iron solution C at a flow rate of 500 ml / min. The oxygen within the reaction system is circulated by a diaphragm pump; the oxygen flow rate can be adjusted down to 50 ml / min during circulation. Excess gas is absorbed by an alkaline solution and then released.
[0037] The complexed iron solution C was heated to 30°C. 2000 ml of hydrogen sulfide MDEA absorption solution C was added over 54 hours. After the addition was complete, stirring was continued and oxygen was introduced for 1 hour. The mixture was then filtered to obtain 44.96 g of yellowish-gray sulfur.
[0038] After adding 40g of MDEA to the filtrate, it can be used as an absorbent to absorb hydrogen sulfide in the above reaction again.
[0039] Figure 1 The image shows the infrared spectrum of elemental sulfur obtained from the desulfurization process in this embodiment, confirming the presence of sulfur.
Claims
1. A method for desulfurizing a laboratory hydrogen sulfide absorbent, characterized in that, Hydrogen sulfide absorbent is added to a complexed iron solution, and an oxidizing gas is introduced into the resulting desulfurization system for oxidation to obtain elemental sulfur. The complexed iron solution contains the following components at the following mass concentrations: 4-15% EDTA iron complex, 0.5-3% hydroxy aldehyde, 0-1% hydroxycarboxylic acid compound, 0.3-0.5% surfactant, and 0.1-0.3% ultralight silica gel. The oxidizing gas is compressed air, oxygen, or ozone oxidation.
2. The desulfurization method for a laboratory hydrogen sulfide absorption solution according to claim 1, characterized in that, The hydrogen sulfide absorption solution is an organic amine solution or an inorganic alkaline solution that has absorbed hydrogen sulfide.
3. The desulfurization method for a laboratory hydrogen sulfide absorption solution according to claim 2, characterized in that, The organic amine solution is an aqueous solution of N-methyldiethanolamine, and the concentration of the aqueous solution of N-methyldiethanolamine is 30-40%; the inorganic alkaline solution is absorbed by an aqueous solution of Na2CO3 or NaOH, and the concentration of the aqueous solution of Na2CO3 is 15% and the concentration of the aqueous solution of NaOH is 30%.
4. A method for desulfurizing a laboratory hydrogen sulfide absorbent solution according to any one of claims 1-3, characterized in that, The iron complex of EDTA is sodium iron salt of EDTA, or a mixture of iron salt and EDTA, or a mixture of iron salt and disodium EDTA, or a mixture of sodium iron salt of EDTA and disodium EDTA, wherein the EDTA or disodium EDTA is used in excess.
5. The desulfurization method for a laboratory hydrogen sulfide absorption solution according to claim 4, characterized in that, The iron salt is ferrous sulfate, ferric sulfate, ferric chloride, ferric ammonium sulfate, or ferrous ammonium sulfate; the hydroxy aldehyde is glucose; the hydroxy carboxylic acid compound is oxalic acid, citric acid, lactic acid, tartaric acid, salicylic acid, or sulfosalicylic acid; and the surfactant is polyacrylamide, polypyrrolidone, polyethylene glycol, or polypropylene glycol.
6. The desulfurization method for a laboratory hydrogen sulfide absorption solution according to claim 5, characterized in that, The pH of the complexed iron solution was adjusted to 7 using a saturated KOH aqueous solution.
7. The desulfurization method for a laboratory hydrogen sulfide absorption solution according to claim 6, characterized in that, The oxidizing gas enters the desulfurization system through a stainless steel sintered filter. The oxidizing gas is circulated in the desulfurization system by a diaphragm pump, and excess gas is discharged after being absorbed by alkaline solution.
8. The desulfurization method for a laboratory hydrogen sulfide absorption solution according to claim 7, characterized in that, The flow rate of the oxidizing gas entering the desulfurization system is 200~500 ml / min, and the flow rate of the oxidizing gas circulated by the diaphragm pump is 50 ml / min.
9. The desulfurization method for a laboratory hydrogen sulfide absorption solution according to claim 8, characterized in that, The hydrogen sulfide absorbent is added to the complexed iron solution in batches. After oxidation is complete, a small amount of acid is added to the desulfurization system to maintain the pH value of the system between 6.0 and 9.
0.
10. The desulfurization method for a laboratory hydrogen sulfide absorption solution according to claim 9, characterized in that, Each time, add 10 ml of hydrogen sulfide absorbent to the complexed iron solution. After 5 minutes, add concentrated hydrochloric acid dropwise to adjust the pH of the desulfurization system to 7 before adding the next batch of hydrogen sulfide absorbent.