Geological carbon sequestration and hydrogen production structure and method based on the spontaneous reaction of water-CO.SUB.2.-active minerals

Abstract

The present application is related to a geological carbon sequestration and hydrogen production structure and method based on the spontaneous reaction of water, CO.sub.2, and active minerals, belonging to the field of carbon sequestration and hydrogen production technology. The method comprises the following steps: (1) CO.sub.2 collection; (2) selecting a site for carbon sequestration and hydrogen production; (3) constructing a space for carbon sequestration and hydrogen production; (4) CO.sub.2 mineralization sequestration and simultaneous hydrogen production; (5) hydrogen collection. The method permanently mineralizes and sequesters CO.sub.2 while using the water-CO.sub.2-active minerals reaction for simultaneous geological hydrogen production. It not only reduces the economic cost of CO.sub.2 geological sequestration but also opens a new pathway for in-situ geological hydrogen production, achieving green and low-carbon hydrogen energy production. The geological carbon sequestration and hydrogen production structure is designed to have low sequestration costs and enable large-scale simultaneous geological hydrogen production.

Claims

1. A geological carbon sequestration and hydrogen production structure, characterized by including comprising a CO.sub.2 injection channel, an H.sub.2 collection channel, a geological reaction mineral layer, and a sealing structure; wherein the geological reaction mineral layer comprises active minerals that serve as both filling material and reaction substrate, an outer layer of the geological reaction mineral layer is enclosed by the sealing structure, wherein the sealing structure prevents the diffusion of CO.sub.2 and hydrogen from inside of the geological reaction mineral layer to outside of the geological reaction mineral layer, wherein the CO.sub.2 injection channel penetrates the sealing structure and extends into the geological reaction mineral layer for injecting CO.sub.2 and water for a reaction, hydrogen produced by the reaction escapes from the geological reaction mineral layer due to a density difference with the active minerals and is collected through the H.sub.2 collection channel that penetrates the sealing structure, wherein the active minerals have a capability of carbon sequestration and hydrogen production, and comprises metal oxides that react with CO.sub.2 to form carbonates and ferrous ions that react with water to produce hydrogen, wherein based on a depth of a carbon sequestration and hydrogen production strata, the geological carbon sequestration and hydrogen production structure is divided into shallow geological carbon sequestration and hydrogen production structures, and deep geological carbon sequestration and hydrogen production structures, and wherein in the shallow geological carbon sequestration and hydrogen production structure, the sealing structure is an artificial confining layer, and the geological reaction mineral layer is an artificial sealing layer, which includes one of an abandoned open-pit mine or an abandoned underground mining tunnel.

2. The geological carbon sequestration and hydrogen production structure according to claim 1, wherein the active minerals include at least one of siderite, nickeliferous siderite, pyroxene, olivine, magnetite, pyrrhotite, and basalt.

3. The geological carbon sequestration and hydrogen production structure according to claim 1, wherein in the deep geological carbon sequestration and hydrogen production structure, H.sub.2 accumulates to form a hydrogen-rich area under a barrier of the sealing structure after escaping from the geological reaction mineral layer, and is recovered through the H.sub.2 collection channel; the sealing structure is a natural sealing cap layer; the geological reaction mineral layer is a natural mineralization sequestration layer, which includes one of a natural saline aquifer, a depleted oil and gas reservoir, or a basalt formation rich in natural fractures.

4. A geological carbon sequestration and hydrogen production method employing the geological carbon sequestration and hydrogen production structure of claim 1 for geological carbon sequestration and hydrogen production, comprising the following steps: (1) CO.sub.2 collection: collecting CO.sub.2 generated from industrial activities; (2) selection of carbon sequestration and hydrogen production site: selecting suitable areas for geological carbon sequestration and hydrogen production through geological surveys and other means, designating the suitable areas as geological reaction mineral layers, dividing the geological reaction mineral layers into shallow geological carbon sequestration and hydrogen production site and deep geological carbon sequestration and hydrogen production site based on the depth of the carbon sequestration and hydrogen production strata; (3) construction of carbon sequestration and hydrogen production space: using sealing structures to enclose the geological reaction mineral layer for sequestering CO.sub.2 and preventing hydrogen leakage, connecting the CO.sub.2 injection channel and the H.sub.2 collection channel through the sealing structure into the geological reaction mineral layer, creating a space that facilitates carbon sequestration and hydrogen production as well as a subsequent collection of products, injecting CO.sub.2 and water into the geological reaction mineral layer through the CO.sub.2 injection channel; (4) CO.sub.2 mineralization sequestration and simultaneous hydrogen production: conducting CO.sub.2 mineralization sequestration and simultaneous hydrogen production through a spontaneous reaction of CO.sub.2, water, and active minerals based on a CO.sub.2-water-active mineral reaction; (5) hydrogen collection: after completion of CO.sub.2 mineralization and hydrogen accumulation, storing hydrogen in rock pores and an upper space of a reservoir within the geological reaction mineral layer, and collecting hydrogen and other byproducts through the H.sub.2 collection channel.

5. The method according to claim 4, wherein in the step (2), the shallow geological carbon sequestration and hydrogen production site are artificial sequestration layers, comprising abandoned open-pit mines and abandoned underground mining tunnels; the deep geological carbon sequestration and hydrogen production site are natural mineralization sequestration layers, comprising natural saline aquifers, depleted oil and gas reservoirs, and basalt formations rich in natural fractures.

6. The method according to claim 5, wherein when the shallow geological carbon sequestration and hydrogen production site is used in the step (2), a construction process of the carbon sequestration and hydrogen production space in the step (3) comprises designing and laying artificial sealing layers, grinding the active minerals and filling the active materials into the artificial sequestration layers, and injecting CO.sub.2 and water, and wherein when the deep geological carbon sequestration and hydrogen production site is used in the step (2), a deep reservoir in the step (3) comprises a natural mineralization sequestration layer and a natural sealing cap layer, with CO.sub.2 and water injected using drilling or abandoned oil and gas wells.

7. The method according to claim 5, wherein when the shallow geological carbon sequestration and hydrogen production site is used in the step (2), in the step (5), hydrogen and byproducts are collected using pipelines as the H.sub.2 collection channel; and when the deep geological carbon sequestration and hydrogen production site is used in the step (2), in the step (5), hydrogen is collected by identifying hydrogen-rich areas and using wellbores as the H.sub.2 collection channel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1: Schematic diagram of carbon sequestration and hydrogen production in an abandoned open-pit mine.

(2) FIG. 2: Schematic diagram of carbon sequestration and hydrogen production in an underground tunnel.

(3) FIG. 3: Schematic diagram of the structure for carbon sequestration and hydrogen production in deep reservoirs.

(4) FIG. 4: Process flow diagram of carbon sequestration and hydrogen production.

(5) FIG. 5: Hydrogen production curve of basalt over time obtained from laboratory experiments.

(6) FIG. 6: Hydrogen production curve of chalcopyrite and pyrite over time obtained from laboratory experiments.

(7) In the figures: Reference signs: 1CO.sub.2 injection channel; 2H.sub.2 collection channel; 3Artificial confining layer; 4Artificial sealing layer; 5Hydrogen-rich area; 6Natural sealing cap layer; 7Natural mineralization sequestration layer.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(8) The following embodiments further illustrate the present invention, but do not limit the scope of the invention to the described embodiments. Experimental methods without specific conditions in the following examples are selected according to conventional methods and conditions or according to the product instructions.

Example 1

(9) This embodiment provides a method for geological carbon sequestration and hydrogen production, utilizing the geological structure of an abandoned open-pit mine as shown in FIG. 1. The method is based on the spontaneous reaction of water, CO.sub.2, and reactive minerals, and the process is illustrated in FIG. 4. The steps are as follows:

(1) CO.SUB.2 .Collection

(10) Collecting CO.sub.2 produced from industrial activities;

(2) Selection of Carbon Sequestration and Hydrogen Production Site

(11) Using the abandoned open-pit mine as the artificial sealing layer 4;

(3) Construction of Carbon Sequestration and Hydrogen Production Space

(12) The artificial sealing layer 4 is filled with ground basalt, pyrrhotite slag, and other reactive rocks, providing a site for the spontaneous reaction of water, CO.sub.2, and reactive minerals for carbon sequestration and hydrogen production. The artificial sealing layer 4 is enclosed by an artificial confining layer 3, isolating it from the surrounding environment, sequestering CO.sub.2, and preventing hydrogen leakage. The CO.sub.2 injection channel 1 extends from the surface to the bottom of the reactive rocks in the artificial sealing layer 4, ensuring sufficient reaction between CO.sub.2, water, and reactive rocks. The H.sub.2 collection channels 2 are located on both sides of the CO.sub.2 injection channel 1, connecting to the top of the artificial sealing layer 4 for easy hydrogen collection. Injecting CO.sub.2 and water;

(4) CO.SUB.2 .Mineralization and Simultaneous Hydrogen Production

(13) CO.sub.2, water, and reactive minerals spontaneously react to achieve CO.sub.2 mineralization and simultaneous hydrogen production;

(5) Hydrogen Collection

(14) After CO.sub.2 mineralization and hydrogen accumulation, hydrogen is stored in the rock pores and the upper space of the geological reaction layer. Hydrogen and other by-products are collected using pipelines as H.sub.2 collection channels.

Example 2

(15) This embodiment provides a method for geological carbon sequestration and hydrogen production, utilizing the geological structure of an underground tunnel as shown in FIG. 2. The method is based on the spontaneous reaction of water, CO.sub.2, and reactive minerals. The steps are as follows:

(1) CO.SUB.2 .Collection

(16) Collecting CO.sub.2 produced from industrial activities;

(2) Selection of Carbon Sequestration and Hydrogen Production Site

(17) Using the underground tunnel as the artificial sealing layer 4;

(3) Construction of Carbon Sequestration and Hydrogen Production Space

(18) The artificial sealing layer 4 is filled with ground basalt, pyrrhotite slag, and other reactive rocks, providing a site for the spontaneous reaction of water, CO.sub.2, and reactive minerals for carbon sequestration and hydrogen production. The artificial sealing layer 4 is enclosed by an artificial confining layer 3, isolating it from the surrounding environment, sequestering CO.sub.2, and preventing hydrogen leakage. The CO.sub.2 injection channel 1 extends from the entrance of the underground tunnel to the bottom of the reactive rocks in the artificial sealing layer 4, ensuring sufficient reaction between CO.sub.2, water, and reactive rocks. The H.sub.2 collection channels 2 are located above the CO.sub.2 injection channel 1, connecting to the top of the reactive rocks in the artificial sealing layer 4 for easy hydrogen collection. Inject CO.sub.2 and water;

(4) CO.SUB.2 .Mineralization and Simultaneous Hydrogen Production

(19) CO.sub.2, water, and reactive minerals spontaneously react to achieve CO.sub.2 mineralization and simultaneous hydrogen production;

(5) Hydrogen Collection

(20) After the carbon dioxide mineralization and hydrogen accumulation processes are completed, hydrogen is stored within the rock pores and the upper space of the geological reaction layer. Hydrogen and other by-products are collected by laying pipelines as H.sub.2 collection channels.

Example 3

(21) This embodiment provides a method for geological carbon sequestration and hydrogen production, utilizing the deep reservoir geological structure for carbon sequestration and hydrogen production, as shown in FIG. 3. The method is based on the spontaneous reaction of water, CO.sub.2, and reactive minerals. The steps are as follows:

(1) CO.SUB.2 .Collection

(22) Collecting CO.sub.2 produced from industrial activities;

(2) Selection of Carbon Sequestration and Hydrogen Production Site

(23) Using a natural saline aquifer, depleted oil and gas reservoir, or a basalt formation rich in natural fractures as the natural mineralization sequestration layer 7;

(3) Construction of Carbon Sequestration and Hydrogen Production Space

(24) The natural mineralization sequestration layer 7 contains reactive minerals for sequestering CO.sub.2 and serves as the site for the spontaneous reaction of water, CO.sub.2, and reactive minerals for carbon sequestration and hydrogen production. The natural sealing cap layer 6 prevents CO.sub.2 and hydrogen from leaking into other areas under pressure. The CO.sub.2 injection channel 1, formed by drilling a well, reaches the bottom of the natural mineralization sequestration layer 7 to inject CO.sub.2 and water into the carbon sequestration and hydrogen production area. The H.sub.2 collection channel 2, also formed by drilling, is located at the top of the carbon sequestration and hydrogen production area for collecting hydrogen. Due to the lower density of hydrogen compared to most fluids, a hydrogen-rich area 5 will form above the natural mineralization sequestration layer 7. Connecting the H.sub.2 collection channel 2 to this area facilitates hydrogen collection;

(4) CO.SUB.2 .Mineralization and Simultaneous Hydrogen Production

(25) CO.sub.2, water, and reactive minerals undergo a spontaneous reaction based on the CO.sub.2-water-reactive mineral system, leading to CO.sub.2 mineralization and simultaneous hydrogen production;

(5) Hydrogen Collection

(26) After CO.sub.2 mineralization and hydrogen accumulation, hydrogen is stored within the rock pores and the upper space of the geological reaction layer. The hydrogen-rich area is identified, and hydrogen is collected using the drilled well;

Example 4

(27) This embodiment studies the effectiveness of the method for CO.sub.2 mineralization and simultaneous hydrogen production under simulated conditions. The working principle of the present invention, which involves the spontaneous reaction of water, CO.sub.2, and reactive minerals to produce hydrogen, can be represented by the following chemical equations:
CO.sub.2+MgO/CaOMgCO.sub.3/CaCO.sub.3(1)
2FeO+H.sub.2OH.sub.2+Fe.sub.2O.sub.3(2)

(28) Carbon dioxide reacts with calcium and magnesium ions in rocks, resulting in mineralization and carbon sequestration (Reaction 1). Additionally, iron-rich rocks undergo interactions with water and CO.sub.2, producing significant amounts of hydrogen (Reaction 2). When carbon dioxide dissolves in water, it forms carbonic acid. The acidity of carbonic acid causes minerals containing ferrous ions, such as pyroxene, magnetite, and olivine, to dissolve and release ferrous ions. These released ferrous ions are adsorbed onto the surface of basalt, where they act as electron donors, reducing water and generating hydrogen.

(29) The effectiveness of spontaneous CO.sub.2-water-basalt reactions for CO.sub.2 mineralization and simultaneous hydrogen production was studied through laboratory experiments. In the experiment, 2 grams of rock samples were first crushed and then placed in a ball mill jar, which was evacuated and ball-milled under anoxic conditions for 20 hours. The rock powder was then extracted with 100 mL of water in an anoxic glovebox and transferred to small glass vials (5 mL each). Dry ice (CO.sub.2) was added to the vials, which were then sealed and allowed to react for a set period. Hydrogen production was measured using gas chromatography. The experiment produced a time-dependent curve of hydrogen production from basalt, as shown in FIG. 5. Hydrogen production increased steadily for the first three days, stabilizing thereafter. The results also indicated that the water-CO.sub.2-basalt reaction produces hydrogen, whereas the water-basalt reaction does not produce hydrogen in the absence of CO.sub.2. This suggests that the coexistence of groundwater and basalt over millions of years has reached a stable state, and hydrogen production occurs only when additional CO.sub.2 is introduced, as in the sequestration process.

(30) The above describes the preferred specific embodiments of the present invention in detail. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the invention without creative efforts. Therefore, any technical solutions derived from logical analysis, reasoning, or limited experiments based on the concept of the invention by those skilled in the art should fall within the protection scope defined by the claims.