Liquid organic hydrogen storage material and application thereof

Abstract

The invention discloses a liquid organic hydrogen storage material and application thereof, and belongs to the technical field of liquid hydrogen storage. The liquid organic hydrogen storage material is an organic compound with a diol structure, the organic compound with the diol structure is one of 1, 5-pentanediol, diethylene glycol and diethanol amine, the liquid organic hydrogen storage material is low in melting point, high in boiling point, safe and low in toxicity, hydrogen is generated through liquid-phase dehydrogenation lactonization, the available hydrogen content is about 3.8%, and the 1, 5-pentanediol structure is one of 1, 5-pentanediol, diethylene glycol and diethanol amine. The 1, 5-pentanediol can be prepared from a biomass platform compound furfural through hydrogenation and hydrogenolysis, and the source is rich; the diethylene glycol and the diethanol ammonia are bulk chemical products, easy to obtain and low in price, and the liquid organic hydrogen storage material has high industrial application value.

Description

Technical Field

[0001] The present invention belongs to the technical field of liquid hydrogen storage, and more specifically, relates to a new liquid organic hydrogen storage material and application thereof. Background Art

[0002] In recent years, due to energy shortages and environmental pollution, clean, green, low-carbon and sustainable new energy sources have attracted much attention. Hydrogen energy has become one of the most promising clean alternative energy sources due to its pollution-free, high-energy and wide sources. The storage and transportation of hydrogen is the difficulty in the development of the hydrogen energy industry. Common hydrogen storage and transportation methods include high-pressure gaseous hydrogen storage and low-temperature liquid hydrogen storage. High-pressure gaseous hydrogen storage has problems such as low hydrogen storage density and poor safety. Liquid hydrogen storage is to liquefy hydrogen at low temperatures. Although liquid hydrogen has a high energy density, the liquefaction process consumes a lot of energy and has high requirements for hydrogen storage tanks.

[0003] The above methods are not suitable for large-scale hydrogen transportation due to high costs. Liquid organic hydrogen storage (LOHCs) technology can solve the problem of large-scale long-distance hydrogen transportation difficulties. At present, liquid organic hydrogen storage mainly consists of some unsaturated organic aromatic hydrocarbons and heterocyclic molecules. Unsaturated organic aromatic hydrocarbons are relatively stable but have disadvantages such as high dehydrogenation temperature. Compared with unsaturated organic aromatic hydrocarbons, heterocyclic molecules have relatively mild dehydrogenation conditions, low dehydrogenation temperature and high hydrogen storage capacity, but most of them have disadvantages such as high melting point, which has great limitations on application. Therefore, the development of new liquid organic hydrogen storage materials has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the present invention aims to provide a compound with a diol structure as a liquid organic hydrogen storage material and its application.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a liquid organic hydrogen storage material, wherein the liquid organic hydrogen storage material is an organic compound having a diol structure, and the chemical formula of the organic compound having a diol structure is shown in Formula I:

[0007]

[0008] Wherein, X is one of CH2, O, and NH.

[0009] In a second aspect, the present invention provides the use of the above-mentioned liquid organic hydrogen storage material in hydrogen storage and transportation.

[0010] Based on the above technical solution, further, the application includes the following steps:

[0011] Dehydrogenation: adding the liquid organic hydrogen storage material and the dehydrogenation catalyst into a reactor, exhausting the air in the reactor with hydrogen, and performing a dehydrogenation reaction at a temperature of 150 to 250° C. and a hydrogen pressure of 0.01 to 0.5 MPa to obtain a liquid organic hydrogen-deficient material;

[0012] Hydrogen storage: Add the liquid organic hydrogen-poor material and hydrogenation catalyst into a reactor, evacuate the air in the reactor with hydrogen, and carry out hydrogenation reaction at a temperature of 150 to 280° C. and a hydrogen pressure of 1 to 5 MPa to obtain a liquid organic hydrogen storage material.

[0013] Based on the above technical solution, further, the dehydrogenation catalyst is a dehydrogenation copper-based catalyst, the copper metal loading of the catalyst is 5-20wt%, and the mass ratio of the dehydrogenation catalyst to the liquid organic hydrogen storage material is 1:5-1:50.

[0014] Based on the above technical solution, further, the hydrogenation catalyst is an ester hydrogenation copper-based catalyst, the copper metal loading of the catalyst is 15-45wt%, and the mass ratio of the hydrogenation catalyst to the liquid organic hydrogen-deficient material is 1:2-1:20.

[0015] Based on the above technical solution, further, the temperature of the dehydrogenation reaction is 150-240°C, and the hydrogen pressure is 0.1-0.3 MPa; the temperature of the hydrogenation reaction is 180-250°C, and the hydrogen pressure is 3-5 MPa.

[0016] Based on the above technical solution, further, the dehydrogenation reaction and the hydrogenation reaction are both carried out under stirring conditions, and the stirring speed is 100-900 rpm.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention proposes a type of liquid organic hydrogen storage material, which has a low melting point, a high boiling point, is safe and low in toxicity, can release hydrogen in an amount of about 3.8wt%, and can generate six-membered ring lactone through dehydrogenation, with a simple reaction, few by-products, and high hydrogen purity. 1,5-Pentanediol can be prepared by hydrogenation and hydrogenolysis of biomass platform compound furfural, and has abundant sources; diethylene glycol and diethanolamine are bulk chemical products with low prices. These three liquid organic hydrogen storage materials have high industrial application value. DETAILED DESCRIPTION

[0019] The present invention is described in detail below with reference to the embodiments, but the embodiments of the present invention are not limited thereto. Obviously, the embodiments described below are only partial embodiments of the present invention. For those skilled in the art, other similar embodiments obtained without creative labor all fall within the protection scope of the present invention.

[0020] Example 1

[0021] This embodiment provides a 1,5-pentanediol liquid organic hydrogen storage material and its application in hydrogen storage and dehydrogenation:

[0022] Dehydrogenation reaction application: 5mL 1,5-pentanediol and 0.5g commercial copper-based dehydrogenation catalyst (copper content 15wt.%) were placed in a 10mL high-pressure reactor, the air in the reactor was evacuated with hydrogen, and 0.1MPa of hydrogen was injected, the temperature was raised to 180°C, 500rpm, and the dehydrogenation reaction stopped (1,5-pentanediol was converted into δ-valerolactone after the reaction). After cooling test, the final 1,5-pentanediol dehydrogenation rate reached 94%, the hydrogen purity was >99.9%, and the selectivity of δ-valerolactone was >99%.

[0023] Application of hydrogenation reaction: 5mL of hydrogen-poor material δ-valerolactone and 1g of commercial copper-based ester hydrogenation catalyst (copper content 40wt.%) were placed in a 10mL high-pressure reactor, the air in the reactor was evacuated with hydrogen, and 4MPa of hydrogen was injected, and the temperature was raised to 200℃, 500rpm, and the pressure of hydrogen was maintained at 4MPa until the hydrogenation reaction stopped. The cooling test showed that the final reaction δ-valerolactone hydrogenation conversion rate was 89%, and the selectivity of 1,5-pentanediol was 99%.

[0024] Example 2

[0025] This embodiment provides a diethylene glycol liquid organic hydrogen storage material and its application in hydrogen storage and dehydrogenation:

[0026] Dehydrogenation reaction application: 5mL of diethylene glycol and 0.5g of commercial copper-based dehydrogenation catalyst (copper content 15wt.%) were placed in a 10mL high-pressure reactor, the air in the reactor was evacuated with hydrogen, and 0.1MPa of hydrogen was injected, the temperature was raised to 180°C, 500rpm, and the dehydrogenation reaction stopped (diethylene glycol was converted to 1,4-dioxane-2-one after the reaction). After cooling test, the final reaction diethylene glycol dehydrogenation rate reached 96%, the hydrogen purity was >99.9%, and the selectivity of the dehydrogenation product 1,4-dioxane-2-one was >99%.

[0027] Application of hydrogenation reaction: 5mL of hydrogen-poor material 1,4-dioxane-2-one and 1g of commercial copper-based ester hydrogenation catalyst (copper content 40wt.%) were placed in a 10mL high-pressure reactor, the air in the reactor was evacuated with hydrogen, and 4MPa of hydrogen was injected, the temperature was raised to 200°C, 500rpm, and the pressure of hydrogen was maintained at 4MPa until the hydrogenation reaction stopped. The cooling test showed that the final reaction 1,4-dioxane-2-one hydrogenation conversion rate was 90%, and the selectivity of diethylene glycol was 99%.

[0028] Example 3

[0029] This embodiment provides a diethanolamine liquid organic hydrogen storage material and its application in hydrogen storage and dehydrogenation:

[0030] Dehydrogenation reaction application: 5mL of diethanolamine and 0.5g of commercial copper-based dehydrogenation catalyst (copper content 15wt.%) were placed in a 10mL high-pressure reactor, the air in the reactor was evacuated with hydrogen, and 0.1MPa of hydrogen was injected, the temperature was raised to 180°C, 500rpm, and the reaction was continued until the dehydrogenation reaction stopped (diethanolamine was converted into 2-morpholinone after the reaction). The cooling test showed that the final reaction diethanolamine dehydrogenation rate reached 95%, the hydrogen purity was >99.9%, and the selectivity of the dehydrogenation product 2-morpholinone was >99%.

[0031] Application of hydrogenation reaction: 5mL of hydrogen-poor material 2-morpholinone and 1g of commercial copper-based ester hydrogenation catalyst (copper content 40wt.%) were placed in a 10mL high-pressure reactor, the air in the reactor was evacuated with hydrogen, and 4MPa of hydrogen was injected, and the temperature was raised to 200℃, 500rpm, and the pressure of hydrogen was maintained at 4MPa until the hydrogenation reaction stopped. The cooling test showed that the final reaction 2-morpholinone hydrogenation conversion rate was 91%, and the selectivity of diethylene glycol was 99%.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A liquid organic hydrogen storage material, characterized in that: The liquid organic hydrogen storage material is an organic compound with a diol structure, and the chemical formula of the organic compound with a diol structure is shown in Formula I: Wherein, X is one of CH2, O, and NH.

2. Application of the liquid organic hydrogen storage material according to claim 1 in hydrogen storage and transportation.

3. The use according to claim 2, characterized in that: The steps include: Dehydrogenation: adding the liquid organic hydrogen storage material and the dehydrogenation catalyst into a reactor, exhausting the air in the reactor with hydrogen, and performing a dehydrogenation reaction at a temperature of 150 to 250° C. and a hydrogen pressure of 0.01 to 0.5 MPa to obtain a liquid organic hydrogen-deficient material; Hydrogen storage: Add the liquid organic hydrogen-poor material and hydrogenation catalyst into a reactor, evacuate the air in the reactor with hydrogen, and carry out hydrogenation reaction at a temperature of 150 to 280° C. and a hydrogen pressure of 1 to 5 MPa to obtain a liquid organic hydrogen storage material.

4. The use according to claim 3, characterized in that: The dehydrogenation catalyst is a dehydrogenation copper-based catalyst, the copper metal loading of the catalyst is 5-20wt%, and the mass ratio of the dehydrogenation catalyst to the liquid organic hydrogen storage material is 1:5-1:

50.

5. The use according to claim 3, characterized in that: The hydrogenation catalyst is an ester hydrogenation copper catalyst, the copper metal loading of the catalyst is 15-45wt%, and the mass ratio of the hydrogenation catalyst to the liquid organic hydrogen-poor material is 1:2-1:

20.

6. The use according to claim 3, characterized in that: The temperature of the dehydrogenation reaction is 150-240°C, and the hydrogen pressure is 0.1-0.3MPa; the temperature of the hydrogenation reaction is 180-250°C, and the hydrogen pressure is 3-5MPa.

7. The method for storing and dehydrogenating according to claim 3, characterized in that: The dehydrogenation reaction and the hydrogenation reaction are both carried out under stirring conditions, and the stirring speed is 100-900 rpm.

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