Carbon dioxide exploitation and storage integrated method

Abstract

The invention relates to the technical field of carbon dioxide sequestration, and provides a carbon dioxide exploitation and sequestration integrated method which comprises the following steps: in an exploitation process of natural gas containing carbon dioxide, capturing carbon dioxide by using an absorbent, and dissolving the captured carbon dioxide in water to form carbon dioxide saturated water; the absorbent comprises the following components in parts by weight: 5-10 parts of pyrazine-activated N-methyl pyrrolidone, 1-3 parts of a polybasic organic amine compound and 1 part of steric hindrance amine, according to the method, carbon dioxide saturated water is injected into a basalt stratum in the stratum through well drilling to be sealed and stored, and exploited carbon dioxide which cannot be utilized is solidified in the stratum again; when natural gas is exploited, carbon dioxide saturated water is sealed in a basalt stratum, additional well drilling is not needed, and the development target of'green and low-carbon 'is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide sequestration, and more particularly to an integrated method for carbon dioxide extraction and sequestration. Background Art

[0002] As the content of greenhouse gases in the atmosphere gradually increases, the global climate has changed significantly, such as the melting of polar glaciers, the rise of sea levels, and the frequent occurrence of extreme weather around the world, threatening the sustainable development of humanity. Therefore, reducing carbon emissions has become a global consensus.

[0003] Carbon capture, utilization, and sequestration technology, as a large-scale greenhouse gas emission reduction technology, has developed rapidly worldwide in recent years. Carbon capture, utilization, and sequestration technology is also an important option for realizing the low-carbon utilization of fossil energy. Specifically, carbon dioxide sequestration technology is a technology that captures carbon dioxide from industrial emission sources or the atmosphere and transports it to a specific location for long-term storage. Its core goal is to reduce the concentration of carbon dioxide in the atmosphere, thereby alleviating global climate change. This technology mainly includes three links: capture, transportation, and sequestration, and is widely used in high-emission industries such as energy, chemical industry, and steel.

[0004] The main ways of carbon dioxide sequestration are ocean sequestration, geological sequestration, and mineral sequestration. Among them, ocean sequestration is to store carbon dioxide in a supercritical state at the bottom of the ocean. Although this method has the advantage of a long sequestration time, it has disadvantages such as high cost, easy leakage, and harm to the marine system. Therefore, seeking a suitable sequestration method and realizing the integration of carbon dioxide extraction and sequestration is of great significance for achieving green and low-carbon. Summary of the Invention

[0005] The purpose of the present invention is to provide an integrated method for carbon dioxide extraction and sequestration, which realizes the storage of carbon dioxide-saturated water in basalt formations while extracting natural gas, without the need for additional drilling, and achieves the development goal of "green and low-carbon".

[0006] The embodiments of the present invention are achieved through the following technical solutions:

[0007] An integrated method for carbon dioxide extraction and sequestration, comprising the following steps:

[0008] (1) During the extraction of natural gas containing carbon dioxide, a carbon dioxide capture agent is used to capture carbon dioxide, and the captured carbon dioxide is dissolved in water to form carbon dioxide-saturated water; the capture agent, by weight, includes: 5-10 parts of pyrazine-activated N-methylpyrrolidone, 1-3 parts of polyorganic amine compound, and 1 part of sterically hindered amine;

[0009] (2) Inject carbon dioxide-saturated water into the basalt formation in the formation through drilling for storage, and re-solidify the unutilizable carbon dioxide extracted in the formation.

[0010] When capturing carbon dioxide, the chemical absorption method is used for capture. Through N-methylpyrrolidone activated by pyrazine, the decarbonization absorption rate is faster, the carbon dioxide absorption load is higher, and the regeneration energy consumption is less. More importantly, after activation, the regeneration temperature is low and the regeneration energy consumption is significantly reduced. Because the traditional ethanolamine absorbent has high energy consumption, mainly due to the relatively large absorption heat, more energy needs to be provided in the desorption process, resulting in high carbon capture energy consumption. However, the N-methylpyrrolidone activated by pyrazine in the present invention overcomes the problems of traditional absorbents and improves the carbon capture efficiency. Compared with the single N-methylpyrrolidone absorbent with a small absorption amount, the present invention activates it and compound it with polyamine organic amine compounds and sterically hindered amines. Although its carbon dioxide absorption ability is relatively weak, its absorption amount is large. After the three are compounded, the absorption rate is faster, the carbon dioxide absorption load is higher, and the regeneration energy consumption is less.

[0011] Use the captured carbon dioxide-saturated water to replace the water drive substance in the natural gas production process to improve the natural gas recovery rate. Especially when the reservoir pressure drops or the production decreases, this simultaneously meets the multi-faceted needs of natural gas production, carbon dioxide storage, and carbon emission reduction, realizes technical complementarity, improves the resource integration degree, reduces the resource exploitation cost, and improves the carbon emission amount.

[0012] Through storage in the basalt formation, the carbonic acid solution reacts with metal ions such as calcium and magnesium in the basalt to form carbonate minerals. The formed carbonate minerals have high stability and can permanently store carbon dioxide underground, ensuring no leakage risk during the storage process. Moreover, the basalt formation usually has multiple layers of solid rock coverage, which can effectively prevent carbon dioxide leakage.

[0013] Further, the polyamine organic amine compound includes: an equimolar mixture of primary amine, secondary amine, and tertiary amine, or a binary organic amine (such as ethylenediamine, propylenediamine), and a tertiary organic amine (trimethylamine, triethylamine).

[0014] Further, the sterically hindered amine is at least one of N,N-diisopropylethylamine, N-methyldicyclohexylamine, and 2,6-diisopropylaniline.

[0015] Further, the preparation method of pyrazine-activated N-methylpyrrolidone is: dissolve N-methylpyrrolidone in the ethanol solution of pyrazine, mix evenly, react for 0.5 - 1 h, then add an antifoaming agent and an antioxidant, and continue to stir for 0.5 - 1 h to make all components fully mixed evenly to obtain pyrazine-activated N-methylpyrrolidone.

[0016] Further, the N-methylpyrrolidone accounts for 80%-90% of the total weight of the absorbent, the pyrazine accounts for 5%-15% of the total weight of the absorbent, the defoamer accounts for 1%-5% of the total weight of the absorbent, and the antioxidant accounts for 0.05%-0.2% of the total weight of the absorbent; the remainder is auxiliary agents such as corrosion inhibitors, stabilizers, etc.

[0017] Further, the defoamer is at least one of dimethyl silicone oil, hydrophobic silica, or dimethylformamide; the antioxidant is at least one of butylated hydroxytoluene, butylated hydroxyanisole, diphenylamine derivatives, or dilauryl thiodipropionate.

[0018] Further, in step (2), when injecting the carbon dioxide-saturated water, a method of alternately injecting carbon dioxide-saturated water and pure water in a composite manner is adopted; this can promote the synergistic effects of geochemical reactions, ion exchange, wettability improvement, etc. during the carbon dioxide injection process, thereby more stably exerting the effect of permanent carbon sequestration and reducing the leakage risk.

[0019] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:

[0020] 1. The present invention aims at carbon dioxide sequestration, captures the natural gas containing carbon dioxide during the exploitation process, and stores it in the carbon dioxide-saturated water injected through the drilled well using the existing basalt formation during the natural gas exploitation process, greatly reducing the cost; while realizing natural gas exploitation, the carbon dioxide-saturated water is stored in the basalt formation, avoiding the need for additional drilling of carbon dioxide sequestration wells, reducing the costs generated by drilling carbon dioxide sequestration wells, and at the same time effectively reducing the carbon dioxide emissions during the natural gas exploitation process, actively promoting natural gas exploitation, and achieving the development goal of "green and low-carbon".

[0021] 2. When the present invention exploits natural gas, a compound of N-methylpyrrolidone activated by pyrazine, a polyorganic amine compound, and a sterically hindered amine are used as absorbents, which improves the carbon capture efficiency and reduces the energy consumption of carbon capture, and the captured carbon dioxide is stored in the basalt formation, having the advantages of permanent carbon sequestration, low leakage risk, long sequestration period (>104 years), and large sequestration capacity. Specific Embodiments

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. For those not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0023] It should be noted that the following examples and comparative examples are all carried out in the Pearl River Estuary Basin of the South China Sea, where the natural gas is rich in carbon dioxide.

[0024] Example 1

[0025] A method for integrated carbon dioxide extraction and storage, comprising the following steps:

[0026] (1) In the process of natural gas extraction containing carbon dioxide, an absorbent is used to capture carbon dioxide, and the captured carbon dioxide is dissolved in water to form carbon dioxide-saturated water; wherein the absorbent comprises, by weight, 8 parts of pyrazine-activated N-methylpyrrolidone, 1 part of ethylenediamine, 1 part of trimethylamine, and 1 part of N,N-diisopropylethylamine;

[0027] The preparation method of pyrazine-activated N-methylpyrrolidone is as follows: N-methylpyrrolidone is dissolved in an ethanol solution of pyrazine (wherein the concentration of pyrazine is 90%), mixed evenly, reacted for 0.5 h, then dimethyl silicone oil and butylated hydroxytoluene were added, and stirring was continued for 0.5 h to ensure that all the ingredients were fully mixed to obtain pyrazine-activated N-methylpyrrolidone.

[0028] Among them, N-methylpyrrolidone accounts for 85% of the total weight of the absorbent, pyrazine accounts for 10% of the total weight of the absorbent, defoaming agent accounts for 3% of the total weight of the absorbent, antioxidant accounts for 0.1% of the total weight of the absorbent, and the rest is stabilizer povidone;

[0029] (2) Carbon dioxide is injected into the basalt formation in the formation by alternating injection of carbon dioxide saturated water and pure water through drilling to seal the carbon dioxide that cannot be used after being mined and re-solidified in the formation.

[0030] Example 2

[0031] A method for integrated carbon dioxide extraction and storage, comprising the following steps:

[0032] (1) In the process of extracting natural gas containing carbon dioxide, an absorbent is used to capture carbon dioxide, and the captured carbon dioxide is dissolved in water to form carbon dioxide-saturated water; wherein the absorbent comprises, by weight, 7 parts of pyrazine-activated N-methylpyrrolidone, 1 part of propylenediamine, 1 part of trimethylamine, 1 part of triethylamine, and 1 part of N-methyldicyclohexylamine;

[0033] The preparation method of pyrazine-activated N-methylpyrrolidone is as follows: N-methylpyrrolidone is dissolved in an ethanol solution of pyrazine, mixed evenly, reacted for 0.5 h, then dimethylformamide and butylated hydroxyanisole are added, and stirring is continued for 0.5 h to ensure that all ingredients are fully mixed to obtain pyrazine-activated N-methylpyrrolidone.

[0034] Among them, N-methylpyrrolidone accounts for 90% of the total weight of the absorbent, pyrazine accounts for 5% of the total weight of the absorbent, defoaming agent accounts for 2% of the total weight of the absorbent, antioxidant accounts for 0.1% of the total weight of the absorbent, and the rest is stabilizer povidone;

[0035] (2) Carbon dioxide is injected into the basalt formation in the formation by alternating injection of carbon dioxide saturated water and pure water through drilling to seal the carbon dioxide that cannot be used after being mined and re-solidified in the formation.

[0036] Example 3

[0037] A method for integrated carbon dioxide extraction and storage, comprising the following steps:

[0038] (1) In the process of extracting natural gas containing carbon dioxide, an absorbent is used to capture carbon dioxide, and the captured carbon dioxide is dissolved in water to form carbon dioxide-saturated water; wherein the absorbent comprises, by weight, 9 parts of pyrazine-activated N-methylpyrrolidone, 1 part of tertiary amine, 1 part of propylenediamine, 1 part of triethylamine, and 1 part of 2,6-diisopropylaniline;

[0039] The preparation method of pyrazine-activated N-methylpyrrolidone is as follows: N-methylpyrrolidone is dissolved in an ethanol solution of pyrazine, mixed evenly, reacted for 0.5 h, and then dimethyl silicone oil and butylated hydroxytoluene are added, and stirring is continued for 1 h to ensure that all ingredients are fully mixed to obtain pyrazine-activated N-methylpyrrolidone.

[0040] Among them, N-methylpyrrolidone accounts for 85% of the total weight of the absorbent, pyrazine accounts for 10% of the total weight of the absorbent, hydrophobic silica accounts for 2% of the total weight of the absorbent, dilauryl thiodipropionate accounts for 0.08% of the total weight of the absorbent, and the remainder is an organotin stabilizer;

[0041] (2) Carbon dioxide is injected into the basalt formation in the formation by alternating injection of carbon dioxide saturated water and pure water through drilling to seal the carbon dioxide that cannot be used after being mined and re-solidified in the formation.

[0042] Comparative Example 1

[0043] The difference between this comparative example and Example 1 is that the absorbent is ethanolamine.

[0044] Comparative Example 2

[0045] The difference between this comparative example and Example 1 is that the N-methylpyrrolidone in the absorbent is not activated.

[0046] Comparative Example 3

[0047] The difference between this comparative example and Example 1 is that the absorbent does not include polyvalent organic amine and sterically hindered amine.

[0048] Experimental Example

[0049] 1. For each of the examples and comparative examples, the carbon capture energy consumption of the captured carbon dioxide was tested. The test results are shown in Table 1. Among them, the carbon capture energy consumption refers to the loss of absorbent in kilograms per ton of carbon dioxide captured;

[0050] Table 1 - Exploration Results after Sequestration of Each Example and Comparative Example

[0051] Carbon capture energy consumption (kg / t) Example 1 0.3 Example 2 0.5 Example 3 0.3 Comparative Example 1 4.7 Comparative Example 2 2.1 Comparative Example 3 1.9

[0052] As can be seen from the results in Table 1, the absorbent of the present invention can significantly increase the absorption amount of carbon dioxide, and has lower carbon capture energy consumption, and can achieve more efficient carbon dioxide absorption and utilization.

[0053] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An integrated method for carbon dioxide extraction and storage, characterized in that It includes the following steps: (1) During the exploitation of natural gas containing carbon dioxide, a carbon dioxide absorbent is used to capture carbon dioxide, and the captured carbon dioxide is dissolved in water to form carbon dioxide saturated water; the absorbent includes: pyrazine-activated N-methylpyrrolidone, polyorganic amine compounds and sterically hindered amines; (2) Inject the carbon dioxide saturated water into the basalt formation in the formation for storage.

2. The integrated method for carbon dioxide extraction and storage according to claim 1, characterized in that The absorbent, by weight, includes: 5-10 parts of pyrazine-activated N-methylpyrrolidone, 1-3 parts of polyorganic amine compounds and 1 part of sterically hindered amines.

3. The integrated method for carbon dioxide extraction and storage according to claim 2, wherein The weight ratio of the pyrazine-activated N-methylpyrrolidone, polyorganic amine compounds and sterically hindered amines is 8:2:

1.

4. The integrated method for carbon dioxide extraction and storage according to claim 1, characterized in that The polyorganic amine compounds include: an equimolar mixture of primary amines, secondary amines and tertiary amines.

5. The integrated method for carbon dioxide extraction and storage according to claim 4, characterized in that, The polyorganic amine compounds also include binary organic amines and / or tertiary organic amines.

6. The integrated method for carbon dioxide extraction and storage according to claim 1, characterized in that The sterically hindered amine is at least one of N,N-diisopropylethylamine, N-methyldicyclohexylamine, 2,6-diisopropylaniline.

7. The integrated method for carbon dioxide extraction and storage according to claim 1, characterized in that, The preparation method of the pyrazine-activated N-methylpyrrolidone is: dissolve N-methylpyrrolidone in an ethanol solution of pyrazine, mix evenly, react for a period of time, then add an antifoaming agent and an antioxidant, and continue to stir for a period of time to make all components fully mixed evenly to obtain pyrazine-activated N-methylpyrrolidone.

8. The integrated method for carbon dioxide extraction and storage according to claim 7, characterized in that, The N-methylpyrrolidone accounts for 80%-90% of the total weight of the absorbent, pyrazine accounts for 5%-15% of the total weight of the absorbent, the antifoaming agent accounts for 1%-5% of the total weight of the absorbent, and the antioxidant accounts for 0.05%-0.2% of the total weight of the absorbent.

9. The integrated method for carbon dioxide extraction and storage according to claim 7, characterized in that, The antifoaming agent is at least one of dimethyl silicone oil, hydrophobic silica or dimethylformamide; the antioxidant is at least one of butylated hydroxytoluene, butylated hydroxyanisole, diphenylamine derivatives, dilauryl thiodipropionate.

10. The integrated method for carbon dioxide extraction and storage according to claim 1, characterized in that, In step (2), when injecting the carbon dioxide saturated water, a carbon dioxide saturated water-pure water alternating composite injection method is adopted.