A hydrogen sulfide separation system and method

Abstract

The invention relates to a hydrogen sulfide separation system (A) and method for producing pure hydrogen (30) with high efficiency and environmental sustainability for the energy sector, while also converting sulfur (40) into economic value by producing sulfuric acid (60) The system includes a gasification unit (100) to convert liquid hydrogen sulfide (10) into gaseous hydrogen sulfide (20), an electrolyzer (200) equipped with a palladium-alloy membrane (290) to separate hydrogen (30) and sulfur (40) through electrolysis, and an oxidation unit (300) to oxidize sulfur (40) using hydrogen (30) and oxygen (50), resulting in sulfuric acid (60). The method enhances energy efficiency, reduces operating costs, and offers a sustainable solution for hydrogen production.

Description

[0001] A HYDROGEN SULFIDE SEPARATION SYSTEM AND METHOD

[0002] Technical Field

[0003] The invention relates to a hydrogen sulfide separation system and method that enables the production of pure hydrogen (H2) with high efficiency and environmental sustainability from hydrogen sulfide (H2S) for use in the energy sector. It also involves converting sulfur, a by-product, into an economically valuable form.

[0004] State of the Art

[0005] Currently, several common techniques are employed for producing pure hydrogen (H2) from gas mixtures containing hydrogen sulfide (H2S). One such method is gas scrubbing, where hydrogen sulfide is separated from the gas mixture using chemicals like ammonia. This process involves washing the gas and absorbing H2S. However, gas scrubbing methods require large quantities of chemical reactants, which increase operating costs. The waste products from chemicals can cause environmental issues and necessitate additional costs and efforts for waste management. Additionally, the scrubbing process consumes significant energy, especially in large-scale operations.

[0006] Another method is adsorption, where materials such as activated carbon or zeolites are used to adsorb H2S from the gas mixture. This method is typically suitable for low H2S concentrations. However, adsorbents reach saturation and require regeneration or replacement, which adds to operational complexity. Adsorption is less effective for high H2S concentrations, and the regeneration process demands additional energy.

[0007] Desulfurization processes involve the reaction of H2S with metal oxides in chemical reactors, resulting in the production of sulfur and water. This process is commonly used in large-scale hydrogen production facilities. However, the sulfur produced must be managed and disposed of in compliance with environmental regulations, which adds to the process's complexity. Additionally, desulfurization processes require substantial energy input for high-temperature and high-pressure reactions, as well as intricate reactor designs and control systems. Cryogenic separation is another method based on the differing boiling points of gases. Since H2S has a higher boiling point than hydrogen, it can be separated cryogenically. However, cryogenic separation requires substantial energy to achieve very low temperatures, involves high initial investment and operational costs, and is not suitable for all gas mixtures, proving effective only under specific conditions.

[0008] Membrane separation is based on the differential permeability of gases through membranes. Special membranes can be used to separate H2S from hydrogen. This invention aims to design a specialized membrane and introduce a system that incorporates it within an electrolyzer, enabling the separation of hydrogen and sulfur, producing pure hydrogen gas, and converting the separated sulfur into sulfuric acid.

[0009] Each of these methods is chosen based on the gas composition, desired purity level, and operational costs, offering specific advantages and limitations depending on the situation.

[0010] Objective of the Invention

[0011] The primary aim of the invention is to efficiently and environmentally sustainably obtain pure hydrogen (H2) from gas mixtures containing hydrogen sulfide (H2S). This is achieved by converting liquid hydrogen sulfide into a gaseous form using a gasification unit and processing it in an electrolyzer equipped with a palladium-alloy membrane. Compared to existing techniques, this method is designed for more effective hydrogen production.

[0012] Another aim is to minimize the environmental impact of sulfur by-products generated during hydrogen production. Sulfur not passing through the membrane is oxidized in an oxidation unit with oxygen and pure hydrogen to form sulfuric acid. This method ensures the safe and efficient disposal of sulfur while creating economic value through sulfuric acid production.

[0013] Additional goals of the invention include increasing energy efficiency and reducing operating costs compared to traditional methods. The use of a palladium-alloy membrane and optimized electrolysis process allows for high-purity hydrogen production with lower energy consumption, providing a sustainable and economical solution for the energy sector.

[0014] Moreover, the invention aims to enhance the flexibility and broad applicability of the process. This invention can be easily integrated into various industrial applications and facilities of different scales. It can adapt to varying hydrogen sulfide concentrations and operating conditions, making it versatile and responsive to diverse industrial needs.

[0015] Overall, this invention seeks to improve the efficiency and environmental sustainability of hydrogen production in the energy sector. The effective production of pure hydrogen and the conversion of sulfur by-products into economic value make this invention advantageous over existing technologies. It represents a significant innovation in hydrogen production and environmental impact management in the energy industry.

[0016] Description of Figures

[0017] Figure-1 : Schematic representation of the hydrogen sulfide separation system.

[0018] Figure-2: Schematic representation of the electrolyzer used in the hydrogen sulfide separation system.

[0019] Explanation of Part References

[0020] A. Hydrogen Sulfide Separation System 220. Lower Cover

[0021] 10. Liquid Hydrogen Sulfide 230. Hydrogen Sulfide Inlet Port

[0022] 20. Gaseous Hydrogen Sulfide 240. Hydrogen Outlet Port

[0023] 30. Hydrogen 250. Sulfur Outlet Port

[0024] 40. Sulfur 260. Anode

[0025] 50. Oxygen 270. Cathode

[0026] 60. Sulfuric Acid 280. Mounting Component

[0027] 100. Gasification Unit 290. Palladium-Alloy Membrane

[0028] 200. Electrolyzer 291. Conductive Plate

[0029] 210. Upper Cover 292. Sealing Element

[0030] 293. Cavity

[0031] 300. Oxidation Unit Detailed Description Of Invention

[0032] Referring to Figure 1, the hydrogen sulfide separation system (A) described in this invention, in its most basic form, includes at least one gasification unit (100) that subjects the supplied liquid hydrogen sulfide (10) to a heating process, converting it into gaseous hydrogen sulfide (20). The gaseous hydrogen sulfide (20) brought into gas form through the said gasification unit is subjected to electrolysis in at least one electrolyzer (200), which separates it into hydrogen and sulfur. Part of the hydrogen gas (30) exiting the said electrolyzer (200) (preferably 1 %-10%), along with sulfur (40) and oxygen supplied from an external source (50), is fed into at least one oxidation unit (300), where the sulfur (40) undergoes an oxidation process to produce sulfuric acid (60).

[0033] Referring to Figure 2, the electrolyzer (200), used to obtain pure hydrogen from hydrogen sulfide, the primary function of the invention, comprises at least one upper cover (210) that closes the upper part of the said electrolyzer (200) to protect the internal components from external factors. The lower part of the electrolyzer (200) is closed by at least one lower cover (220) to ensure that the electrolysis cell is securely and stably positioned. Gaseous hydrogen sulfide (20) enters the system (A) through at least one hydrogen sulfide inlet port (230). The electrolyzer also includes at least one anode (260), which serves as the positive pole during the electrolysis process, and at least one cathode (270), which serves as the negative pole. Conductive plates (291) are provided to ensure efficient electrical transmission within the electrolysis cell. At least one sealing element (292), located between the conductive plates (291), ensures the gas-tightness of the electrolysis cell. The said sealing element (292) is essentially a gasket. A palladium-alloy membrane (290) with high selectivity and permeability is positioned within a cavity (293) formed in the body of the said conductive plates (291). During the electrolysis process, the gaseous hydrogen sulfide (20) mixture is separated into hydrogen (30) and sulfur (40) by the electric current passing between the said anode (260) and cathode (270), resulting in the production of pure hydrogen (30) gas. The palladium-alloy membrane (290) allows only hydrogen ions to pass through, and these ions recombine on the other side of the membrane (290) to form hydrogen gas (H2). In this way, pure hydrogen gas (30) is obtained. This process is particularly important for hydrogen (30) gas production because hydrogen sulfide is a compound found in natural gas and other hydrocarbon resources. The use of the palladium-alloy membrane (290) makes hydrogen production more efficient and purer. This technology is also environmentally significant, as hydrogen sulfide is a naturally toxic gas and can be safely separated through this process.

[0034] During the electrolysis stage, certain assumptions were made to ensure the accuracy of the process and to enhance the realism of the results. Firstly, it was assumed that all gases behave ideally, and environmental conditions are constant. The ambient temperature was taken as 25 °C, and the pressure as atmospheric pressure, i.e., 101.325 kPa. The heat exchange between the system and the environment was considered negligible, and changes in kinetic and potential energies, as well as exergies, were ignored. The process was assumed to operate in a steady and continuous flow, with all components functioning at constant temperature and pressure. Electrical transmission was assumed to occur without losses. Specifically for the electrolysis conditions, the pressures and temperatures of H2S, H2, and sulfur gases during electrolysis were assumed to remain constant (150 °C, 0.8 MPa), and the mass flow rate of hydrogen sulfide was taken as 100 kg per hour.

[0035] The detailed process of hydrogen sulfide separation is as follows:

[0036] Input Conditions and Separation Process:

[0037] Hydrogen sulfide gas with a flow rate of 100 kg / hour enters the electrolyzer (200) at 80 °C and 800 kPa pressure, where it is electrochemically separated into hydrogen and sulfur dimers.

[0038] The overall reaction for the electrochemical process is:

[0039] H2S(g) H2(g) + % S2(g)

[0040] Anode Reaction: H2S(g) — > 1 S2(g) + 2H++ 2e~

[0041] Cathode Reaction: 2H++ 2e~ — > H2

[0042] The energy requirement for separating each cubic meter of H2S is approximately 0.38 kW. The hydrogen sulfide separation system (A) operates using the following sequence:

[0043] • Liquid hydrogen sulfide (10) is converted into gaseous hydrogen sulfide (20) by heating in the gasification unit (100).

[0044] • Gaseous hydrogen sulfide (20) is transferred to the electrolyzer (200).

[0045] • The electrolyzer (200) processes the gaseous hydrogen sulfide (20) through electrolysis and separates it into hydrogen (30) and sulfur (40) using the palladium-alloy membrane (290).

[0046] • A portion of the hydrogen gas (30) exiting the electrolyzer (200) is combined with sulfur (40) and oxygen (50) in the oxidation unit (300).

[0047] • The oxidation unit (300) oxidizes sulfur (40) and produces sulfuric acid (60).

[0048] As a result, the hydrogen sulfide separation system (A) described in this invention is designed to improve efficiency and environmental sustainability in hydrogen production for the energy sector. The system operates under ideal conditions, with an ambient temperature of 25 °C and atmospheric pressure of 101.325 kPa. Liquid hydrogen sulfide (10) is heated and converted into a gas in the gasification unit (100), then processed by the electrolyzer (200) containing a palladium-alloy membrane (290) at 150 °C and 0.8 MPa pressure. During this process, H2S gas is separated into hydrogen (H2) and sulfur dimers (!4 S2), with an energy requirement of approximately 0.38 kW per cubic meter of H2S. The hydrogen (30) and sulfur (40) exiting the electrolyzer (200) are further processed in the oxidation unit (300) to produce sulfuric acid (60), ensuring environmentally friendly disposal.

[0049] This innovative and integrated system offers lower operational costs and higher energy efficiency compared to traditional methods, providing an effective and sustainable solution for producing pure hydrogen (30) from gas mixtures containing hydrogen sulfide. The invention represents a significant advancement in hydrogen production and waste management in the energy sector.

Claims

CLAIMS1. The invention relates to a hydrogen sulfide separation system (A) designed for use in the energy sector, enabling the production of pure hydrogen (30) with high efficiency and environmental sustainability from hydrogen sulfide while also converting sulfur (40) into economic value, characterized by:• at least one gasification unit (100) that subjects the supplied liquid hydrogen sulfide (10) to a heating process, converting it into gaseous hydrogen sulfide (20),• at least one electrolyzer (200) comprising; at least one hydrogen sulfide inlet port (230) that allows the gaseous hydrogen sulfide (20) to enter the system (A), at least one anode (260) functioning as the positive pole during the electrolysis process and at least one cathode (270) functioning as the negative pole, conductive plates (291) ensuring efficient electrical transmission within the electrolysis cell, at least one palladium-alloy membrane (290) with high selectivity and permeability, positioned within a cavity (293) formed in the body of the said conductive plates (291), which separates the gaseous hydrogen sulfide (20) into hydrogen (30) and sulfur (40) through the electric current passing between the anode (260) and the cathode (270), thereby obtaining pure hydrogen (30),• at least one oxidation unit (300) that combines a portion of the hydrogen gas (30) exiting the said electrolyzer (200), sulfur (40), and externally supplied oxygen (50) to subject the sulfur (40) to an oxidation process and produce sulfuric acid (60).

2. The hydrogen sulfide separation system according to claim 1, characterized by at least one upper cover (210) that closes the upper part of the said electrolyzer (200) to protect the internal components from external factors.

3. The hydrogen sulfide separation system according to claim 1, characterized by at least one lower cover (220) that closes the lower part of the electrolyzer (200) to ensure the secure and stable positioning of the electrolysis cell.

4. The hydrogen sulfide separation system according to claim 1, characterized by at least one sealing element (292) located between the conductive plates (291) to ensure the gas-tightness of the electrolysis cell.

5. The hydrogen sulfide separation system according to Claim 4, characterized by the sealing element (292) being a gasket.

6. A hydrogen sulfide separation method designed for use in the energy sector to produce pure hydrogen (30) with high efficiency and environmental sustainability from hydrogen sulfide while also converting sulfur (40) into economic value, characterized by:• at least one gasification unit (100) that subjects the supplied liquid hydrogen sulfide (10) to a heating process, converting it into gaseous hydrogen sulfide (20),• at least one electrolyzer (200) comprising; at least one hydrogen sulfide inlet port (230) that allows the gaseous hydrogen sulfide (20) to enter the system (A), at least one anode (260) functioning as the positive pole during the electrolysis process and at least one cathode (270) functioning as the negative pole, conductive plates (291) ensuring efficient electrical transmission within the electrolysis cell, at least one palladium-alloy membrane (290) with high selectivity and permeability, positioned within a cavity (293) formed in the body of the said conductive plates (291), which separates the gaseous hydrogen sulfide (20) into hydrogen (30) and sulfur (40) through the electric current passing between the anode (260) and the cathode (270), thereby obtaining pure hydrogen (30),• at least one oxidation unit (300) that combines a portion of the hydrogen gas (30) exiting the said electrolyzer (200), sulfur (40), and externally supplied oxygen (50) to subject the sulfur (40) to an oxidation process and produce sulfuric acid (60).The method is characterized by the following steps;• heating the liquid hydrogen sulfide (10) using a gasification unit (100) to convert it into gaseous hydrogen sulfide (20),• transferring the gaseous hydrogen sulfide (20) to an electrolyzer (200),• subjecting the gaseous hydrogen sulfide (20) to electrolysis in the electrolyzer (200) and separating it into hydrogen (30) and sulfur (40) using the palladiumalloy membrane (290) inside the electrolyzer (200),• directing a portion of the hydrogen gas (30) exiting the electrolyzer (200), along with the sulfur (40) and oxygen (50), to an oxidation unit (300),• subjecting the sulfur (40) to an oxidation process in the oxidation unit (300) and producing sulfuric acid (60).

7. The hydrogen sulfide separation method according to claim 6, characterized by the electrolysis process being conducted under conditions of 150 °C and 0.8 MPa pressure.

8. The hydrogen sulfide separation method according to Claim 6, characterized by the amount of pure hydrogen (30) gas directed to the oxidation unit (300) being between 1 % and 10%.

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