Classifications

• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
  • C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
  • C01B3/06—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of inorganic compounds containing electro-positively bound hydrogen, e.g. water, acids, bases, ammonia, with inorganic reducing agents
  • C01B3/08—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of inorganic compounds containing electro-positively bound hydrogen, e.g. water, acids, bases, ammonia, with inorganic reducing agents with metals
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
  • C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
  • C01B3/06—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of inorganic compounds containing electro-positively bound hydrogen, e.g. water, acids, bases, ammonia, with inorganic reducing agents
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B33/00—Silicon; Compounds thereof
  • C01B33/113—Silicon oxides; Hydrates thereof
  • C01B33/12—Silica; Hydrates thereof, e.g. lepidoic silicic acid
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/30—Hydrogen technology
  • Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

Definitions

• the present invention relates to a method for producing hydrogen.
• Hydrogen is produced in a conventional manner from hydrocarbons, ie from the energy sources containing coal, coal, petroleum, natural gas. It is also known to obtain hydrogen from water in an electrolytic manner. However, this process is very energy-intensive (about 5 kWh / m 3 H 2 ). In addition, water is only widely available in certain areas of the world (not in desert areas). If one takes into account the diffusion behavior of hydrogen, its storage and transportation are very dangerous, since explosive mixtures (oxyhydrogen gas) form when mixed with air. Hydrogen liquefaction for storage is associated with a high expenditure of energy. Hydrogen is considered to be the energy source of the future, since the generation of energy from hydrogen (combustion with oxygen to water) does not produce any environmentally harmful gases (CO, C0 2 , SO, etc.).
• the invention has for its object to provide a method for generating hydrogen which can be carried out independently of carbon sources.
• the invention shows three ways. According to a first approach, a method for producing hydrogen by reacting amorphous silicon with water is provided according to the invention.
• Amorphous silicon serves as the starting substance for the process according to the invention.
• the production of amorphous silicon is known and is also used in new processes proposed German patent applications 102 17 140.8, 102 17 124.6 and 102 17 126.2.
• the starting material for the production of amorphous silicon is silicon dioxide, which is largely available as a natural occurrence on earth (especially in desert areas), so that ultimately amorphous silicon is a safe source for the production of hydrogen the hydrogen can be generated on site, ie independently of carbon sources and / or water sources, without transport and storage problems.
• Solid bodies are referred to as amorphous, the molecular building blocks of which are arranged randomly rather than in crystal lattices.
• Amorphous silicon (a-Si) is much cheaper to produce than crystalline silicon.
• the invention therefore includes that the generation of hydrogen according to the invention can also be carried out using microcrystalline or very finely crystalline silicon. Suitable limits are to be determined empirically.
• the method according to the invention can basically be carried out with both types of amorphous silicon, the non-chemically documented, black amorphous silicon generally having a better reactivity than the chemically documented, brown (yellow) amorphous silicon.
• Black chemically unoccupied amorphous silicon is therefore preferably used for the process according to the invention.
• the method according to the invention can advantageously be carried out at room temperature if there is a corresponding reactivity of the amorphous silicon, which is the case in particular with the black chemically unoccupied amorphous silicon.
• the reactivity of the silicon depends on the coating.
• the reactivity (reaction temperature) of the amorphous silicon can be controlled in a targeted manner by controlling the chemical coating. Investigations have shown that amorphous brown silicon coated with NH 3 has a better reactivity than amorphous brown silicon coated with 0 2 .
• the method according to the invention can also be carried out under certain circumstances with microcrystalline or very finely crystalline silicon in powder form, where this substance has an even lower reactivity than the brown amorphous silicon mentioned above.
• silicon dioxide Si0 2
• Si0 2 silicon dioxide
• hydrogen is generated by reacting amorphous silicon with an alcohol.
• the alcohols (ROH) used are preferably those in which R is Me (methyl) or Et (ethyl).
• the reaction of Si dm with alcohols gives tetraalkoxysilanes (Si (OR) 4 ), where R generally means an organic radical, preferably an alkyl radical.
• tetraalkoxysilanes also referred to as silicic acid esters, are produced in a conventional manner by reacting silicon halides with alcohols.
• the process according to the invention is used to produce directly from silicon, so that one process step is saved. There are a multitude of uses for the tetraalkoxysilanes, so that these compounds are of great importance as a by-product obtained in the process according to the invention.
• hydrogen is generated by reacting amorphous silicon with a carboxylic acid.
• Acetic acid CH3COOH
• solid silicon tetraacetate being produced in the reaction of Si dlI with acetic acid, which as Basic material for the construction of organosilanes and siloxanes / silicones is of great importance.
• the compounds Si (OR) 4 obtained in the production of hydrogen with an alcohol or a carboxylic acid, where R forms an organic radical, in particular alkyl or carboxylic acid radical, are converted into Si0 2 + H ⁇ R by hydrolysis.
• the need for the compound Si (OR) 4 , in particular Si (OAc) 4 is met, the alcohol or the carboxylic acid (acetic acid) can be recovered.
• the H 2 produced in an equimolar manner according to the invention can be used in mobile (fuel cell) and stationary systems.
• the required hydrogen was previously generated in converters in front of the fuel cell from CH 3 OH or CH 4 , whereby in each case C0 2 was produced.
• the process according to the invention is CO 2 -free, and valuable and practically non-toxic products are obtained which can be recycled when the demand is saturated.
• the brown amorphous silicon can be set by deactivating the Si surface (chemical coating), any temperatures for the reaction to generate hydrogen.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Health & Medical Sciences (AREA)
• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Silicon Compounds (AREA)
• Catalysts (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 2002
  • 2002-12-11 DE DE10258072A patent/DE10258072A1/de not_active Withdrawn
• 2003
  • 2003-12-11 JP JP2004557807A patent/JP4566751B2/ja not_active Expired - Fee Related
  • 2003-12-11 WO PCT/DE2003/004086 patent/WO2004052774A2/de active Application Filing
  • 2003-12-11 US US10/538,603 patent/US20060246001A1/en not_active Abandoned
  • 2003-12-11 CN CNB2003801082846A patent/CN100475687C/zh not_active Expired - Fee Related
  • 2003-12-11 AU AU2003294647A patent/AU2003294647A1/en not_active Abandoned
  • 2003-12-11 EP EP03785555A patent/EP1597195A2/de not_active Withdrawn

Non-Patent Citations (1)

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