A hydrogen production method based on the serpentinization reaction of mafic-ultramafic rocks

Abstract

The present application provides a kind of hydrogen production method based on basic-ultrabasic rock serpentinization reaction.This method uses Fe-rich basic-ultrabasic rock as raw material, and occurs serpentinization reaction with seawater under high temperature and high pressure conditions to produce hydrogen gas.By utilizing the efficient hydrogen production characteristics of serpentinization reaction under specific conditions, the present application solves the problems of high cost, low efficiency and lack of environmental friendliness in the current hydrogen energy industry.Serpentinization reaction, as a naturally occurring mineral transformation process, can release hydrogen gas under specific geological conditions, providing a new and environmentally friendly hydrogen production approach, which helps to explore and develop natural hydrogen reservoirs, more effectively utilize the energy resources in the earth's interior, and promote the sustainable development of hydrogen energy industry.

Description

Cross-references to related applications

[0001] This invention claims priority to Chinese Patent Application No. CN202510401382.7, filed on April 1, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to the fields of renewable energy and hydrogen energy technology, and more specifically, to a method for producing hydrogen based on the serpentinization reaction of basic-ultrabasic rocks. Background Technology

[0003] With the increasing global energy demand and growing environmental awareness, hydrogen energy, as a clean and efficient energy source, is receiving increasing attention for its development and utilization. Current industrial hydrogen production processes can be categorized into three types: first, industrial by-product hydrogen production, represented by coke oven gas, chlor-alkali tail gas, and ethane and propane dehydrogenation; second, hydrogen production through water electrolysis; and third, hydrogen production from fossil fuels, represented by coal and natural gas. In addition, some hydrogen production methods are still under research and development, such as solar photocatalytic water splitting, nuclear hydrogen production, and biological hydrogen production. Large-scale industrial hydrogen production processes require a rational balance between economic efficiency and low-carbon environmental friendliness. In summary, each of the three main hydrogen production processes mentioned above has its own advantages and disadvantages.

[0004] Fossil fuels (coal, oil, natural gas, etc.) are the primary energy source today, with over 90% of global hydrogen production coming from fossil fuels. While coal-to-hydrogen technology has significant economic advantages due to its low cost, this process, relying on fossil fuels, still suffers from a series of problems, including high carbon emissions, complex waste gas and tailings treatment procedures, high energy consumption, low energy conversion efficiency, underutilization of raw material resources, and the fact that fossil fuels are non-renewable resources. Therefore, it cannot fundamentally solve the huge future hydrogen energy gap.

[0005] Industrial by-product hydrogen production is a process that extracts hydrogen from by-product gases produced in industries such as chemical, petrochemical, and metallurgy. This process allows for the resource utilization of by-product gases, recovery of effective components, and removal of pollutants such as sulfides. Industrial by-product hydrogen production introduces almost no other carbon sources; its CO2 emissions are the sum of the CO2 from the original exhaust gas and the indirect CO2 emissions from the energy consumed in the hydrogen production process. The indirect CO2 emission intensity falls between that of hydrogen produced from fossil fuels and hydrogen produced through renewable energy electrolysis of water. From an economic perspective, the cost of large-scale industrial waste gas hydrogen production is lower than the break-even point for hydrogen fuel cell vehicles. Therefore, industrial by-product hydrogen is currently a good choice for low-carbon, low-cost hydrogen sources. However, this process also suffers from high energy consumption, excessive investment, and low utilization rates. While recent advancements in separation and purification processes and adsorption separation technologies have partially solved these problems, the total amount of industrial by-product gas is ultimately limited, and it still consumes fossil fuels.

[0006] Electrolysis of water to produce hydrogen is pollution-free and yields high-purity hydrogen, but it also suffers from high energy consumption and large investment costs. Renewable energy sources (such as wind and solar power) can be used to produce hydrogen through water electrolysis, converting surplus electricity from renewable energy sources into hydrogen energy, thus achieving efficient utilization of renewable energy. While this technology contributes to achieving carbon neutrality, it is currently in its incubation stage and has not yet reached the 10% hydrogen production efficiency required for commercial application, thus it cannot yet replace hydrogen production from fossil fuels. Summary of the Invention

[0007] The purpose of this invention is to provide a hydrogen production method based on the serpentinization reaction of basic-ultrabasic rocks.

[0008] The method proposed in this invention is based on naturally occurring basic-ultrabasic rocks within the Earth. By simulating the high-temperature and high-pressure environment inside the Earth, it achieves hydrothermal hydrogen production, offering advantages such as environmental friendliness, low energy consumption, and abundant raw materials. Furthermore, since the serpentinization reaction of basic-ultrabasic rocks is exothermic, once the reaction begins, the heat generated by the chemical reaction can be used to obtain the required temperature, balancing heat losses through convection and conduction, as well as cooling caused by the injection of colder fluids.

[0009] To achieve the objective of this invention, in a first aspect, this invention provides a method for producing hydrogen based on the serpentinization reaction of basic-ultrabasic rocks, using Fe-rich basic-ultrabasic rocks as raw materials, and reacting them with seawater under high temperature and high pressure conditions to produce hydrogen.

[0010] The reaction equation is as follows: Fe 2+ +H₂O→Fe 3+ +H2.

[0011] Preferably, the Fe-rich basic-ultrabasic rocks include, but are not limited to, Fe-rich... 2+ Pyroxene and / or peridot.

[0012] Preferably, the high temperature and high pressure conditions are: 220℃~300℃ (selected as 250℃), 500 bar.

[0013] Furthermore, the reaction takes place inside a reactor, and an inert gas is supplied before the rock raw material is added to the reactor to reduce the oxygen concentration inside the reactor to the target concentration.

[0014] Furthermore, the reactor is equipped with heating elements, a pressure control system, and a gas collection system.

[0015] Furthermore, the gas produced by the reaction is collected by a gas collection system and then cooled, dried, and purified to obtain high-purity hydrogen.

[0016] Furthermore, the rock raw material is pretreated before the reaction, including crushing and screening to obtain particles with a particle size of 100 nm to 40 μm (e.g., 40 μm and 100 nm) before the reaction.

[0017] Secondly, the present invention provides a hydrogen production system for serpentinization reaction of basic-ultrabasic rocks, the hydrogen production system comprising: (1) Reactor, used for serpentinization reaction of basic-ultrabasic rocks; (2) Heating element, used to provide the heat energy required for the reaction; (3) Pressure control system, used to maintain pressure stability during the reaction process; (4) A gas collection system, including a cooler, a dryer and a gas purifier, for collecting and purifying the hydrogen produced during the reaction and connecting it to a hydrogen storage tank.

[0018] Furthermore, the hydrogen production system also includes a raw material pretreatment device for crushing and screening basic to ultrabasic rocks.

[0019] By employing the above technical solution, the present invention has at least the following advantages and beneficial effects: This invention addresses the current challenges of high cost, low efficiency, and insufficient environmental friendliness in hydrogen production by utilizing the highly efficient hydrogen production characteristics of serpentinization under specific conditions. Serpentinization, a naturally occurring mineral transformation process, can release hydrogen under specific geological conditions, providing a novel and environmentally friendly hydrogen production pathway. By precisely controlling the conditions of the serpentinization reaction, such as temperature, pressure, and initial reactant particle size, this invention achieves efficient and stable hydrogen production, providing new impetus for the development of the hydrogen energy industry. The development of serpentinization hydrogen production technology not only reduces the production cost and improves efficiency but also reduces the environmental pollution that may occur in traditional hydrogen production processes, demonstrating significant environmental advantages. Furthermore, combining geological exploration with serpentinization hydrogen production technology facilitates the exploration and development of natural hydrogen reservoirs, enabling more effective utilization of the Earth's internal energy resources and promoting the sustainable development of the hydrogen energy industry. Detailed Implementation

[0020] This invention provides a novel hydrogen production method based on the serpentinization reaction principle of intermediate-ultramafic rocks in nature. The method includes the following steps: selecting Fe-rich... 2+Using basic to ultrabasic rocks as reactants, and preparing an appropriate amount of seawater, a reaction vessel capable of withstanding high temperature and pressure is prepared. The vessel is equipped with a heating device and a pressure control system to ensure temperature and pressure stability during the reaction. The basic to ultrabasic rocks are crushed to an appropriate particle size and mixed with seawater in a certain proportion before being added to the reaction vessel. The temperature inside the reaction vessel is increased by the heating device, while the pressure control system maintains the pressure within a predetermined range. Under high temperature (220℃~300℃) and high pressure (500 bar) conditions, the basic to ultrabasic rocks undergo a hydrothermal reaction with water, producing hydrogen gas. The reaction equation is Fe... 2+ +H₂O→Fe 3+ +H2. High-purity hydrogen is collected through a gas separation device inside the reactor. This method effectively avoids the high carbon emissions of traditional fossil fuel hydrogen production and the high cost and high water quality requirements of water electrolysis hydrogen production, achieving a highly efficient hydrogen production goal with a reasonable balance between economics and environmental protection.

[0021] The present invention adopts the following technical solution: This invention provides a method for hydrogen production via serpentinization reaction of basic-ultrabasic rocks, comprising the following steps: selecting Fe-rich rocks... 2+ Using basic to ultrabasic rocks as raw materials, the rocks are subjected to serpentinization under high temperature and high pressure conditions, and the hydrogen produced during the reaction is collected and purified.

[0022] Furthermore, before the reaction, the basic to ultrabasic rocks are pretreated, including crushing and sieving to obtain particles with a diameter of 100 nm to 40 μm (e.g., 40 μm and 100 nm) to improve the efficiency of the serpentinization reaction.

[0023] Furthermore, the serpentinization reaction is carried out in a specific reactor equipped with heating elements, a pressure control system, and a gas collection system to ensure that the reaction process proceeds under preset temperature and pressure conditions. Inert gas is supplied before the basic or ultrabasic rock is added to the reactor to reduce the oxygen concentration within the reactor to the target concentration.

[0024] Furthermore, the gases produced by the serpentine reaction are collected through a gas collection system and then cooled, dried, and purified to obtain high-purity hydrogen.

[0025] The present invention also provides a hydrogen production system for serpentinization reaction of basic-ultrabasic rocks, comprising: a reaction vessel for carrying out serpentinization reaction of basic-ultrabasic rocks; a heating element for providing the heat energy required for the reaction; a pressure control system for maintaining pressure stability during the reaction process; and a gas collection system, including a cooler, a dryer, and a gas purifier, for collecting and purifying the hydrogen generated during the reaction and connecting it to a hydrogen storage tank.

[0026] Furthermore, the system also includes a raw material pretreatment device for crushing and screening basic to ultrabasic rocks.

[0027] Furthermore, the system also includes a control system for monitoring and controlling parameters such as temperature, pressure, and gas flow rate during the reaction process to ensure the safety and efficiency of the reaction.

[0028] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art, and the raw materials used are all commercially available products.

[0029] Example 1: Hydrogen production method based on serpentinization reaction of basic-ultrabasic rocks This embodiment provides a novel hydrogen production method based on the serpentinization reaction principle of intermediate-ultrabasic rocks in nature, including the following steps: selecting Fe-rich... 2+ Basic to ultrabasic rocks (rich in Fe) 2+ Using pyroxene or olivine as the reaction raw material, and preparing an appropriate amount of seawater; a reaction vessel capable of withstanding high temperature and pressure is prepared, equipped with an internal heating device and pressure control system to ensure the stability of temperature and pressure during the reaction. The basic-ultrabasic rock is crushed to an appropriate particle size, mixed with seawater in a certain proportion, and then added to the reaction vessel. The temperature inside the reaction vessel is increased by the heating device, while the pressure control system maintains the pressure inside the reaction vessel within a predetermined range. Under high temperature (250℃) and high pressure (500 bar) conditions, the basic-ultrabasic rock undergoes a hydrothermal reaction with water, producing hydrogen gas. The reaction equation is Fe... 2+ +H₂O→Fe 3+ +H2. High-purity hydrogen gas is collected through a gas separation device inside the reactor.

[0030] Specifically, Peridot was selected as the reaction raw material and prepared into particles with a diameter of 100 nm. 0.1 g of peridot sample was weighed, placed in a gold tube, and 100 μL of 30 g / L NaCl solution was added and sealed.

[0031] The sealed gold tube was placed in a cold-sealed high-pressure autoclave system for hydrothermal reaction. The system was first pressurized to 500 bar, then heated to 250°C, and reacted for one month under a constant 500 bar condition.

[0032] After the reaction was completed, the autoclave was rapidly cooled to near room temperature within a short time to terminate the water-rock reaction. The pressure was then slowly released, the gold tube was removed, and weighed again to confirm that no leakage occurred during the reaction. After opening the gold tube, the gaseous and solid products generated by the reaction were collected for gas composition analysis and mineralogical characterization, respectively.

[0033] The test results showed that significant hydrogen was generated in the system under the above conditions, with a hydrogen yield of 76.85 μmol / g. Analysis of the solid products after the reaction revealed the formation of serpentine, magnetite, and brucite.

[0034] The above results show that olivine reacts with 30 g / L NaCl solution at 250℃ and 500 bar for one month to undergo significant serpentinization and generate hydrogen, thus verifying the feasibility and effectiveness of the hydrogen production method based on the serpentinization reaction of basic-ultrabasic rocks in this invention.

[0035] Example 2: Hydrogen production method based on serpentinization reaction of basic-ultrabasic rocks Peridot was selected as the reaction raw material and prepared into particles with a diameter of 100 nm. 0.1 g of peridot sample was weighed, placed in a gold tube, and 100 μL of 30 g / L NaCl solution was added and sealed.

[0036] The sealed gold tube was placed in a cold-sealed high-pressure autoclave system for hydrothermal reaction. The system was first pressurized to 500 bar, then heated to 250°C, and reacted for 2 months under a constant 500 bar condition.

[0037] After the reaction was completed, the autoclave was rapidly cooled to near room temperature within a short time to terminate the water-rock reaction. The pressure was then slowly released, the gold tube was removed, and weighed again to confirm that no leakage occurred during the reaction. After opening the gold tube, the gaseous and solid products generated by the reaction were collected for gas composition analysis and mineralogical characterization, respectively.

[0038] The test results showed that significant hydrogen was generated in the system under the above conditions, with a hydrogen yield of 136.95 μmol / g. Analysis of the solid products after the reaction revealed the formation of serpentine, magnetite, and brucite.

[0039] Example 3: Hydrogen production method based on serpentinization reaction of basic-ultrabasic rocks Peridot was selected as the reaction raw material and prepared into particles with a diameter of 40 μm. 0.1 g of peridot sample was weighed, placed in a gold tube, and 100 μL of 30 g / L NaCl solution was added and sealed.

[0040] The sealed gold tube was placed in a cold-sealed high-pressure autoclave system for hydrothermal reaction. The system was first pressurized to 500 bar, then heated to 250°C, and reacted for 2 months under a constant 500 bar condition.

[0041] After the reaction was completed, the autoclave was rapidly cooled to near room temperature within a short time to terminate the water-rock reaction. The pressure was then slowly released, the gold tube was removed, and weighed again to confirm that no leakage occurred during the reaction. After opening the gold tube, the gaseous and solid products generated by the reaction were collected for gas composition analysis and mineralogical characterization, respectively.

[0042] The test results showed that significant hydrogen was generated in the system under the above conditions, with a hydrogen yield of 79.82 μmol / g. Analysis of the solid products after the reaction revealed the formation of serpentine, magnetite, and brucite.

[0043] Comparative Example 1 Peridot was selected as the reaction raw material and prepared into particles with a diameter of 100 nm. 0.1 g of peridot sample was weighed, placed in a gold tube, and 100 μL of 30 g / L NaCl solution was added and sealed.

[0044] The sealed gold tube was placed in a constant temperature oven for hydrothermal reaction. The system was heated to 50°C and reacted for 2 months under constant 1 bar conditions.

[0045] After the experiment, the gold tube was removed and allowed to cool naturally to ambient temperature to terminate the reaction. The gold tube was then opened, and the resulting gaseous and solid products were collected for gas composition analysis and mineralogical characterization, respectively.

[0046] The test results showed that hydrogen was generated in the system under the above conditions, with a hydrogen yield of 0.029 μmol / g. Analysis of the solid products after the reaction showed that no obvious solid products were produced.

[0047] Comparative Example 2 Peridot was selected as the reaction raw material and prepared into particles with a diameter of 40 μm. 0.1 g of peridot sample was weighed, placed in a gold tube, and 100 μL of 30 g / L NaCl solution was added and sealed.

[0048] The sealed gold tube was placed in a constant temperature oven for hydrothermal reaction. The system was heated to 50°C and reacted for 2 months under constant 1 bar conditions.

[0049] After the experiment, the gold tube was removed and allowed to cool naturally to ambient temperature to terminate the reaction. The gold tube was then opened, and the resulting gaseous and solid products were collected for gas composition analysis and mineralogical characterization, respectively.

[0050] The test results showed that hydrogen was generated in the system under the above conditions, with a hydrogen yield of 0.029 μmol / g. Analysis of the solid products after the reaction showed that no obvious solid products were produced.

[0051] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for hydrogen production based on the serpentinization reaction of basic-ultrabasic rocks, characterized in that, Hydrogen was produced by reacting Fe-rich basic to ultrabasic rocks with seawater under high temperature and high pressure conditions to undergo serpentinization. The reaction equation is as follows: Fe 2+ +H₂O→Fe 3+ +H2.

2. The method according to claim 1, characterized in that, The Fe-rich basic-ultrabasic rocks include Fe-rich... 2+ Pyroxene and / or peridot.

3. The method according to claim 1, characterized in that, The high temperature and high pressure conditions are: 220℃~300℃, 500 bar.

4. The method according to claim 3, characterized in that, The high temperature and high pressure conditions are: 250℃, 500 bar.

5. The method according to claim 1, characterized in that, The reaction takes place inside a reactor. Before the rock raw material is added to the reactor, an inert gas is supplied to reduce the oxygen concentration inside the reactor to the target concentration.

6. The method according to claim 5, characterized in that, The reactor is equipped with heating elements, a pressure control system, and a gas collection system.

7. The method according to claim 6, characterized in that, The gas produced by the reaction is collected by a gas collection system and then cooled, dried and purified to obtain high-purity hydrogen.

8. The method according to any one of claims 1-7, characterized in that, Before the reaction, the rock raw material is pretreated, including crushing and screening to obtain particles with a particle size of 100 nm to 40 μm.

9. A hydrogen production system based on the serpentinization reaction of basic-ultrabasic rocks, characterized in that, The hydrogen production system includes: (1) Reactor, used for serpentinization reaction of basic-ultrabasic rocks; (2) Heating element, used to provide the heat energy required for the reaction; (3) Pressure control system, used to maintain pressure stability during the reaction process; (4) A gas collection system, including a cooler, a dryer and a gas purifier, for collecting and purifying the hydrogen produced during the reaction and connecting it to a hydrogen storage tank.

10. The hydrogen production system according to claim 9, characterized in that, The hydrogen production system also includes a feedstock pretreatment unit.