CN-122029125-A - Natural hydrogen mining using methane pyrolysis

Abstract

The invention relates to a method for treating a raw material natural gold hydrogen-hydrocarbon mixture containing in the range of 5 to 95 Vol% of hydrogen naturally occurring in the crust, mantle and/or pit and in the range of 5 to 95 Vol% of gaseous hydrocarbons, in particular methane, more preferably in the range of 10 to 80 Vol% of hydrogen and in the range of 20 to 90 Vol% of gaseous hydrocarbons, in particular methane, relative to the total volume of the hydrogen-hydrocarbon mixture, wherein the natural gold hydrogen-hydrocarbon mixture is fed into a hydrocarbon pyrolysis unit and the hydrocarbons are pyrolyzed into hydrogen and solid carbon, and wherein the solid carbon is separated from the hydrogen product stream.

Inventors

• G. Hennessy
• MOULIN DOMINIQUE
• D. VOLLICKER
• D. RICK
• J.P. JOHNSON
• T. Wilde

Assignees

• 巴斯夫欧洲公司

Dates

Publication Date

20260512

Application Date

20241001

Priority Date

20231006

Claims (14)

1. 1. A process for the combined purification and hydrogen production of a raw material naturally occurring hydrogen-hydrocarbon mixture containing in the range of 5 to 95 Vol% of naturally occurring hydrogen in the crust, mantle and/or earth's core and in the range of 5 to 95 Vol% of gaseous hydrocarbons relative to the total volume of the hydrogen-hydrocarbon mixture, wherein said natural hydrogen-hydrocarbon mixture is fed to a hydrocarbon pyrolysis unit and these gaseous hydrocarbons are pyrolyzed into hydrogen and solid carbon, and wherein the solid carbon is separated from the hydrogen product stream.
2. 2. The method of claim 1, wherein the molar ratio of hydrogen to hydrocarbon of the naturally occurring hydrogen-hydrocarbon mixture fed to the reactor varies in the range of 10 to 1 during the pyrolysis process.
3. 3. The method according to claim 2, wherein the molar ratio of hydrogen to hydrocarbon of the naturally occurring hydrogen-hydrocarbon mixture fed into the reactor is not constant during the pyrolysis process.
4. 4. A process according to any one of claims 1 to 3, wherein the feedstock naturally occurring hydrogen-hydrocarbon mixture contains in the range 75 to 90 Vol% of naturally occurring hydrogen in the crust, mantle and/or pit and in the range 10 to 25 Vol% of gaseous hydrocarbons.
5. 5. The method of any one of claims 1 to 4, wherein a naturally occurring hydrogen-hydrocarbon mixture is produced, pretreated, and fed into the hydrocarbon pyrolysis unit, wherein the production unit is upstream of and fluidly connected to the pretreatment unit, and the pretreatment unit is upstream of and fluidly connected to the hydrocarbon pyrolysis unit.
6. 6. The method of any one of claims 1 to 5, wherein the pyrolysis unit is electrically heated.
7. 7. The method of any one of claims 1 to 6, wherein the pyrolysis process is conducted in a moving bed, fluidized bed, or fixed bed reactor, wherein the bed contains a substrate and the substrate has a size in the range of 0.1 to 10 mm.
8. 8. The method according to any one of claims 1 to 7, wherein the pyrolysis process is carried out in a moving bed reactor at a temperature in the range of 500 ℃ to 2000 ℃ and a pressure in the range of 1 to 100 bar, wherein the bed contains carbon material, metal, ceramic and/or mixtures thereof as a substrate, and wherein the substrate is guided in countercurrent to said naturally occurring hydrogen-hydrocarbon mixture.
9. 9. The process of any one of claims 1 to 8, wherein the hydrogen-hydrocarbon mixture is introduced via the bottom of a moving bed reactor having a temperature of 10 ℃ to 200 ℃, and the substrate is introduced via the top of the moving bed reactor having a temperature of 10 ℃ to 200 ℃.
10. 10. The process according to any one of claims 1 to 9, wherein the hydrogen product stream exits via the top of the moving bed reactor with a temperature of 10 ℃ to 200 ℃, and the pyrolytic carbon exits via the bottom of the moving bed reactor with a temperature of 10 ℃ to 200 ℃.
11. 11. The process according to any one of claims 1 to 10, wherein the total feed to the pyrolysis unit containing (i) the naturally occurring hydrogen-hydrocarbon mixture of the feedstock and (ii) optionally further hydrogen is continuously adjusted to a fixed H2/CH4 molar feed, i.e. operating point, by increasing or decreasing the amount of internal hydrogen product stream recycle and/or by adding further hydrogen and/or further hydrocarbons.
12. 12. The method of claim 11, wherein the operating point is adjusted to a fixed H2/CH4 molar feed by increasing or decreasing the amount of internal hydrogen product stream recycle.
13. 13. The process according to any one of claims 1 to 12, wherein the natural hydrogen-hydrocarbon mixture fed into the hydrocarbon pyrolysis unit contains a sulfur-containing component.
14. 14. The process according to any one of claims 1 to 13, wherein the hydrogen product stream is used for the production of ammonia, synthesis gas, aromatics, ketones, aldehydes, cyclic hydrocarbons, amines, alcohols.

Description

Natural hydrogen mining using methane pyrolysis The invention relates to a method for treating raw natural hydrogen-hydrocarbon mixtures containing in the range of 5 to 95 Vol% of hydrogen naturally occurring in the crust, mantle and/or earth's core and in the range of 5 to 95 Vol% of gaseous hydrocarbons, especially methane, more preferably in the range of 10 to 80 Vol% of hydrogen and in the range of 20 to 90 Vol% of gaseous hydrocarbons, especially methane, relative to the total volume of the hydrogen-hydrocarbon mixture, wherein the natural hydrogen-hydrocarbon mixture is fed to a hydrocarbon pyrolysis unit and the hydrocarbons are pyrolyzed to hydrogen and solid carbon, and wherein the solid carbon is separated from the hydrogen product stream. Background In the context of carbon neutralization, hydrogen is considered the potentially cleanest energy source for this century. Currently, hydrogen is produced in industry mainly (96%) [2] by reforming hydrocarbons (such as coal and natural gas) and to a small extent by electrolysis of water. Although reforming of hydrocarbons emits large amounts of CO 2 (about 9 million tons/year 2), the production of hydrogen by electrolysis of water is relatively expensive and requires large amounts of renewable energy. In recent years, different technologies for hydrocarbon pyrolysis, mainly natural gas pyrolysis, are being developed. However, in contrast to reforming, gaseous carbon dioxide is not produced, but rather solid high purity carbon is produced. Methane pyrolysis is therefore considered a promising sustainable technology for future hydrogen production. In addition, methane pyrolysis is used to produce high purity carbon, such as carbon nanotubes. US 2004/141654 describes a method for the catalytic production of carbon nanotubes in a fluidized bed of nanoagglomerates using a supported nanoscale metal catalyst as bed material. Lower hydrocarbons are used as feedstock. Hydrogen, nitrogen and carbon monoxide are also fed into the reactor, (i) to reduce the nanoscale transition metal oxide particles to nanoscale metal particles, (ii) to reduce the catalyst, and (iii) to dilute the feedstock and thus manipulate and control the hydrocarbon composition, for example, to minimize soot formation. US 2022/0306462 discloses a process for producing high purity hydrogen by coupling hydrocarbon pyrolysis with electrochemical hydrogen separation. It is disclosed that thermal decomposition can be carried out in a fixed bed reactor, a fluidized bed reactor or a moving bed reactor. Natural gas is typically used as a feedstock for hydrocarbon pyrolysis. Pre-purification of natural gas by catalytic desulfurization prior to the pyrolysis is disclosed. The electrochemically hydrogen separated hydrogen-depleted anode tail gas is recycled and mixed with a natural gas feed to produce a feed mixture of natural gas and up to 20 Vol% hydrogen from the tail gas. WO 2023/059520 describes hydrocarbon pyrolysis in a plasma reactor. A hydrocarbon feedstock such as natural gas or a biological feedstock may be mixed with a process gas such as hydrogen. The process gas may be a recycled product gas from pyrolysis of the hydrocarbon, like hydrogen. Process gases are typically required to minimize soot formation. Natural hydrogen, also known as "Jin Qing", "white hydrogen", "virgin hydrogen" or "geological hydrogen", is a term used to describe hydrogen that is naturally produced in the crust, mantle and/or nucleus and is the most economical and sustainable potential source of hydrogen, although exploration and development has just begun. Because of its potential benefit as an environmentally friendly fuel, hydrogen is known as "gold hydrogen" or "white hydrogen" and does not emit any CO 2 during its formation. The natural process leading to the formation of natural hydrogen is not yet clear, but three theories based on geologic processes are discussed by experts as the most probable theory [1]: Serpentine, i.e. the reaction between water and ultra-mafic rock (e.g. olivine). Radiation decomposition of water to form hydrogen. Trapping large amounts of hydrogen in the earth's core in the form of iron hydrides and iron hydrates during the formation of the earth, which are released over time. Natural hydrogen gas leaks have recently been found in several areas around the world, such as the united states, russia, brazil, australia, marry (Mali), and in spanish and france. These images (occurrence) indicate that natural hydrogen is not an isolated phenomenon and may be more extensive than originally thought. Since the 19 th century, a greater number has been documented, and examples [1] are listed here: First-time manifestations described in 1888 by Mendeleev (Ukeland) c H2 =5.8-7.5 Vol% Russian (1970, maryland (Udachnaya) well) 100,000 m3/d for 3 days, c H2 = 27-47 Vol% New Zealand (1972); c H2 = 75.8 Vol% U.S. (1984) Hoffmann well): c H2 = 96.3 Vol% Philippines (1990, 25 burning) c H2 =41-45: 45 Vol% Tur