Oxide manufacturing method
The method uses renewable energy-derived hydrogen to produce metal oxides with reduced CO2 emissions by transferring thermal energy to a heat transfer medium at 80-150°C, enabling efficient energy conversion and stable reactor operation.
Patent Information
- Application Number
- JP2025543813
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-02-10
- Filing Date
- 2024-01-31
- Publication Date
- 2026-02-25
AI Technical Summary
Current pyrogenic processes for producing finely dispersed metal and semi-metal oxide powders contribute significantly to CO2 emissions and fossil carbon release, and existing methods face challenges in efficiently collecting thermal energy at reactor wall temperatures below 120°C while minimizing energy consumption.
A method involving the use of renewable energy-derived hydrogen for flame formation and transferring thermal energy from the flame to a heat transfer medium at 80-150°C, followed by further energy conversion to generate superheated steam for electricity production.
Reduces CO2 emissions and fossil energy consumption by maximizing energy reuse, while maintaining stable reactor conditions and producing finely dispersed metal oxides.
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Abstract
Description
[Technical Field]
[0001] The present invention relates to an exothermic process for producing metal oxides or metalloid oxides, comprising introducing metal and / or metalloid precursors into a flame formed by burning a gas mixture comprising oxygen and hydrogen, at least a portion of the hydrogen being obtained from the electrolysis of water or an aqueous solution using electrical energy obtained at least in part from a renewable energy source, and at least a portion of the thermal energy of the flame being transferred to a first heat transfer medium, thereby heating the first heat transfer medium to a temperature in the range of between 80°C and 150°C. [Background technology]
[0002] Finely dispersed metal oxide and metalloid oxide powders, such as silica, alumina, and titania, are needed for a wide range of technological applications today. Well-established routes for their production are based on exothermic processes, i.e., processes involving flame hydrolysis and / or flame pyrolysis of precursors (see Ullmann's Encyclopedia of Industrial Chemistry (1982) Volume 21, page 464). The flames used in these processes are typically formed by combining and igniting a stream of a hydrogen-containing gas mixture and a gas mixture containing oxygen with a burner. Volatile metal or metalloid precursors are fed into the hydrogen or oxygen stream, or directly into the flame, and converted to finely dispersed metal oxide and / or metalloid oxide powders.
[0003] Today's hydrogen supply for pyrogenic processes is typically obtained by steam reforming of fossil methane residues, resulting in the release of fossil carbon into the atmosphere.
[0004] CH4+2H2O→4H2+CO2, Furthermore, steam reforming requires a significant input of thermal energy to achieve the high processing temperatures required for it, however, generating thermal energy in a typical today's industrial environment releases additional fossil carbon into the atmosphere.
[0005] Therefore, the production of finely dispersed metal oxide and semi-metal oxide powders by current pyrogenic processes contributes to the atmospheric release of fossil carbon. Given the large-scale operation of current global pyrogenic processes, their contribution to carbon dioxide emissions is clearly significant. Given the increasing urgency to mitigate global warming caused by CO2 atmospheric emissions, reducing such emissions in all chemical processes, including the pyrogenic production of metal and semi-metal oxides, is becoming a top priority. Based on this, it is essential that evaluation of alternatives to current pyrogenic processes must include consideration of the CO2 emissions of the entire process, rather than simply focusing on improvements accessible in individual substeps. [Prior art documents] [Non-patent literature]
[0006] [Non-Patent Document 1] Ullmann's Encyclopedia of Industrial Chemistry(1982)Volume 21, page 464 Summary of the Invention [Problem to be solved by the invention]
[0007] Therefore, one of the problems to be solved by the present invention is to provide a pyrogenic process for producing finely dispersed metal oxide and semi-metal oxide powders, such as silica, alumina, titania, etc., that has a lower CO2 footprint.
[0008] While collecting and using thermal energy downstream of the burner site may at first glance appear to be a valuable means of reducing the energy consumption of exothermic processes, technical requirements present severe obstacles to the generation of superheated steam, typically required for converting thermal energy into electrical energy, with temperatures exceeding 200°C and pressures exceeding 5 bar. International Publication No. 2008000302 discloses that it is beneficial to cool the walls of a flame hydrolysis reactor to a temperature below 500°C, e.g., 170°C. In other cases, it is proposed to cool the reactor walls to even lower temperatures, e.g., below 120°C, so that the corresponding heat exchanger, usually filled with circulating water, can be operated at lower pressures and the reactor wall material (e.g., aluminum) is protected from the destructive effects of high temperatures and pressures. Therefore, collecting thermal energy from exothermic processes conducted according to these specifications becomes extremely difficult.
[0009] US Pat. No. 6,248,495 discloses a method for producing metal oxides by introducing metal precursors into a flame, the flame used being formed by burning a gas mixture containing oxygen and hydrogen.
[0010] US 2009 / 280048 discloses a method for producing metal oxides in which burners are used and the reactor walls are cooled to a temperature below 500°C.
[0011] Therefore, another problem solved by the present invention is to provide an exothermic process for producing finely dispersed metal oxide and semi-metal oxide powders, such as silica, alumina, titania, etc., with maximum reuse of energy produced in a process operating at reactor wall temperatures below 120°C, while reducing overall CO2 emissions and minimizing fossil energy consumption. [Means for solving the problem]
[0012] The present invention The above-mentioned problem is solved by a method for producing a metal oxide or semi-metal oxide, comprising the steps of: 1. A method for producing a metal oxide or semi-metal oxide, comprising: (a) introducing a metal precursor and / or a metalloid precursor into a flame, - the flame used in step (a) is formed by burning a gas mixture comprising oxygen and hydrogen, - introducing hydrogen, at least a portion of which is obtained from the electrolysis of water or an aqueous solution using electrical energy obtained at least in part from a renewable energy source; (b) transferring at least a portion of the thermal energy of the flame used in step (a) to a first heat transfer medium by at least one exchanger, thereby heating the first heat transfer medium to a maximum temperature in the range between 80 and 150°C; The problem is solved by the present invention using a method comprising: DETAILED DESCRIPTION OF THE INVENTION
[0013] In a preferred embodiment of the present invention, the metal oxide or semi-metal oxide is selected from oxides of aluminum (Al), titanium (Ti), zirconium (Zr), yttrium (Y), lithium (Li), magnesium (Mg), lanthanum (La), cerium (Ce), iron (Fe), zinc (Zn), and silicon (Si).
[0014] In a particularly preferred embodiment of the present invention, the metal oxide or semi-metal oxide is selected from oxides of aluminum (Al), titanium (Ti), and silicon (Si).
[0015] According to the present invention, a metal or metalloid precursor is a compound containing one or more metals or metalloids which, when exposed to a flame formed by burning a gas mixture containing oxygen and hydrogen, is chemically converted to a mixture of one or more solid (25°C and atmospheric pressure) oxides of the metals or metalloids and compounds that are gaseous or volatile at 25°C and atmospheric pressure.
[0016] In a preferred embodiment of the present invention, the metal or semi-metal precursor is selected from aluminum chloride, aluminum oxychloride, titanium tetrachloride, titanium trichloride, titanium oxychloride, tetraalkoxytitanates, tetraalkoxysilicates, cyclic or acyclic siloxanes, silicon tetrachloride, trichlorosilane, methyltrichlorosilane, dichlorosilane, monochlorosilane or mixtures thereof.
[0017] The formation of a flame by burning a gas mixture containing oxygen and hydrogen and introducing a metal precursor and / or metalloid precursor therein, according to the present invention, can be achieved by any means known to those skilled in the art. A comprehensive description of such exothermic processes particularly suited for the purposes of the present invention is described in the art; see, for example, Ullmann's Encyclopedia of Industrial Chemistry (1982) Volume 21, page 464.
[0018] According to the present invention, at least a portion of the hydrogen used to generate the flame is obtained from the electrolysis of water or an aqueous solution using electrical energy obtained at least in part from a renewable energy source. A wide range of methods for the production of hydrogen from the electrolysis of water or an aqueous solution are available in the art, all of which can be used in the context of the present invention.
[0019] According to the present invention, at least a portion of the thermal energy of the flame used in step (a) is transferred to the first heat transfer medium by at least one exchanger, thereby heating the first heat transfer medium to a maximum temperature within a range between 80°C and 150°C. The limited temperature range is advantageous over known methods that use higher temperatures. The lower heat exchanger temperature (80-150°C) results in better burner material stability in the flame process, leading to better product properties and less heat loss (as a function of the fourth power of temperature) due to less heat radiation in the process.
[0020] Typically, the transfer of the thermal energy of the flame to the first heat transfer medium is accomplished by a heat exchanger positioned in suitable proximity to the flame.
[0021] Heat exchangers are well known and widely used in many environments to recover thermal energy from fluids. They function by transferring heat from one fluid to another through a solid wall separating the two. Several designs of heat exchangers exist. Typical heat exchanger designs include double-tube heat exchangers, shell-and-tube heat exchangers, plate heat exchangers, and condenser and boiler heat exchangers. Heat exchangers are classified into three main categories based on the flow arrangement. In parallel-flow heat exchangers, two fluids enter the exchanger at the same end and travel parallel to each other to the other side. In counterflow heat exchangers, fluids enter the exchanger at both ends. Counterflow designs are the most efficient in that they can transfer the most heat from the heat transfer medium per unit mass due to the higher average temperature difference along any unit length. In crossflow heat exchangers, the fluids travel approximately perpendicular to each other through the exchanger. Corresponding equipment is commercially available and widely used by those skilled in the art of chemical process technology.
[0022] Several heat transfer media suitable as the first heat transfer medium are known to those skilled in the art. In addition to a sufficiently low freezing point, a sufficiently high boiling point, and a sufficiently high chemical stability, such heat transfer media typically also exhibit some or all of the following properties with respect to the process equipment used: high specific heat capacity, high heat transfer coefficient, high thermal conductivity, low viscosity, non-flammability, non-explosiveness, low toxicity, and non-corrosiveness.
[0023] In a preferred embodiment of the present invention, the first heat transfer medium is water.
[0024] In a preferred embodiment of the present invention, the renewable energy source is selected from the group consisting of solar energy, wind energy, geothermal energy, hydroelectric power from flowing water, tidal energy, energy obtained from the combustion of biomass, waste or biofuels, and combinations of these energy sources.
[0025] The maximum temperature range of 80-150°C of the first heat transfer medium is suitable for its use, for example, for heating houses, but is usually too low to be further converted into anything particularly useful for industrial environmental purposes, for example, power generation.
[0026] Therefore, in a particularly preferred embodiment of the present invention, the heat of the first heat transfer medium is further transferred to a second heat transfer medium, and electrical energy is generated by passing this second heat transfer medium, heated to a temperature above its boiling point under standard conditions, through an expansion device. According to this preferred embodiment, the method of the present invention comprises the following steps: (a) introducing a metal precursor and / or a metalloid precursor into a flame, - the flame used in step (a) is formed by burning a gas mixture comprising oxygen and hydrogen, - introducing hydrogen, at least a portion of which is obtained from the electrolysis of water or an aqueous solution using electrical energy obtained at least in part from a renewable energy source; (b) transferring at least a portion of the thermal energy of the flame used in step (a) to the first heat transfer medium, thereby heating the first heat transfer medium to a maximum temperature in the range between 80 and 150°C; (c) transferring at least a portion of the thermal energy of the first heat transfer medium exhibiting a maximum temperature in the range between 80°C and 150°C to a second heat transfer medium by at least one exchanger, thereby heating the second heat transfer medium to a temperature above its boiling point under standard conditions, thereby generating a superheated second heat transfer medium having a pressure of at least 1.1 bar abs; (d) passing at least a portion of the superheated second heat transfer medium through a steam turbine, thereby producing electrical energy.
[0027] Thus, according to this preferred embodiment, at least a portion of the thermal energy of the first heat transfer medium, which exhibits a maximum temperature in the range between 80°C and 150°C, is transferred to the second heat transfer medium, thereby heating the second heat transfer medium to a temperature above its boiling point under standard conditions, resulting in a superheated second heat transfer medium having a pressure of at least 1.1 bar abs. Typically, the transfer of thermal energy from the first heat transfer medium to the second heat transfer medium is accomplished using a heat exchanger. A general description of suitable heat exchangers was given above with respect to step (b). Again, corresponding equipment is commercially available and widely used by those skilled in the art of chemical process technology.
[0028] In the context of the present invention, standard conditions are defined as a temperature of 273.15 K = 0°C and a pressure of 100000 Pa = 1,000 bar.
[0029] According to the invention, the superheated second heat transfer medium exhibits a pressure of at least 1.1 bar abs, the pressure being defined in absolute terms, ie compared to a perfect vacuum.
[0030] Several heat transfer media suitable as the second heat transfer medium are known to those skilled in the art. In addition to a sufficiently low freezing point, a sufficiently high boiling point, and a sufficiently high chemical stability, such heat transfer media typically also exhibit some or all of the following properties with respect to the process equipment used: high specific heat capacity, high heat transfer coefficient, high thermal conductivity, low viscosity, non-flammability, non-explosiveness, low toxicity, and non-corrosiveness.
[0031] In a preferred embodiment of the present invention, the second heat transfer medium is selected from hydrocarbons having up to 6 carbon atoms, such as propane, cyclopropane, butane, isobutane, pentane, cyclopentane, hexane, and halogenated hydrocarbons, and mixtures thereof.
[0032] At least a portion of the superheated second heat transfer medium is passed through a steam turbine, thereby generating electrical energy. The term "steam turbine" in the context of the present invention refers to any device in which gas pressurized to more than 1 bar abs can be expanded, i.e., reduced in pressure to produce work, which can in turn be used to drive a compressor or a generator. Equipment for this method step is commercially available and widely used by those skilled in the art.
[0033] In a preferred embodiment of the present invention, the steam turbine is an expansion turbine, also known as a turboexpander.
[0034] In a preferred embodiment of the present invention, at least a portion of the first heat transfer medium is one of the following: - heating the metal precursor and / or metalloid precursor before use in step (a) of the method, - heating at least one gas prior to use in step (a) of the method. is used for one or more of the following:
[0035] The use of a first heat transfer medium to heat the metal / metalloid precursor or to heat one or more gases prior to their introduction into the flame can save energy and reduce emissions throughout the process. Heat transfer from the first heat transfer medium to the metal / metalloid precursor or one or more gases can be achieved using conventional process equipment, such as heat exchangers, which are commercially available and known in the art.
[0036] In a preferred embodiment of the invention, at least a portion of the electrical energy produced by the method is generated by: obtaining hydrogen from the electrolysis of water or an aqueous solution and using at least a portion of this hydrogen in step (a) of the process; - heating the metal precursor and / or metalloid precursor before use in step (a) of the method, - heating at least one gas prior to use in step (a) of the method, - powering at least one pump used in the method; is used for one or more of the following:
[0037] In a preferred embodiment of the present invention, the metal oxide or semi-metal oxide is selected from oxides of aluminum (Al), titanium (Ti) and silicon (Si); At least a portion of the first heat transfer medium is: o heating the metal precursor and / or said metalloid precursor prior to use in step (a) of the method; o heating at least one gas prior to use in step (a) of the method. is used for one or more of the following:
[0038] In a further preferred embodiment of the present invention, the metal oxides and / or semi-metal oxides are selected from oxides of aluminum (Al), titanium (Ti) and silicon (Si); At least a portion of the electrical energy generated by the method is obtaining hydrogen from the electrolysis of water or an aqueous solution and using at least a portion of this hydrogen in step (a) of the process; o heating the metal or metalloid precursor prior to use in step (a) of the method; o heating at least one gas prior to use in step (a) of the method; o powering at least one pump used in the method; is used for one or more of the following:
[0039] In a preferred embodiment of the invention, oxygen is obtained from the electrolysis of water or an aqueous solution using electrical energy obtained at least in part from a renewable energy source, and at least a portion of this oxygen is used in step (a) of the method.
Claims
1. 1. A method for producing a metal oxide or semi-metal oxide, comprising the steps of: (a) introducing a metal precursor and / or a metalloid precursor into a flame; - the flame used in step (a) is formed by burning a gas mixture comprising oxygen and hydrogen, - introducing at least a portion of said hydrogen obtained from the electrolysis of water or an aqueous solution using electrical energy obtained at least in part from a renewable energy source; (b) transferring at least a portion of the thermal energy of the flame used in step (a) to a first heat transfer medium by at least one exchanger, thereby heating the first heat transfer medium to a maximum temperature in the range between 80 and 150°C; A method comprising:
2. Steps below: (c) transferring at least a portion of the thermal energy of the first heat transfer medium exhibiting a maximum temperature in the range between 80°C and 150°C to a second heat transfer medium by at least one exchanger, thereby heating the second heat transfer medium to a temperature above its boiling point under standard conditions, thereby generating a superheated second heat transfer medium having a pressure of at least 1.1 bar abs; (d) passing at least a portion of the superheated second heat transfer medium through a steam turbine, thereby producing electrical energy; The method of claim 1 further comprising:
3. 3. The method according to any one of claims 1 to 2, wherein the renewable energy source is selected from the group consisting of solar energy, wind energy, geothermal energy, hydroelectric power from flowing water, tidal energy, energy obtained from the combustion of biomass, waste or biofuels, and combinations of these energy sources.
4. 4. The method of any one of claims 1 to 3, wherein the metal oxide or semi-metal oxide is selected from oxides of aluminum (Al), titanium (Ti), zirconium (Zr), yttrium (Y), lithium (Li), magnesium (Mg), lanthanum (La), cerium (Ce), iron (Fe), zinc (Zn), and silicon (Si).
5. The method according to any one of claims 1 to 4, wherein the metal oxide or semi-metal oxide is selected from oxides of aluminum (Al), titanium (Ti), and silicon (Si).
6. 6. The method according to any one of claims 1 to 5, wherein the metal or semi-metal precursor is selected from aluminum chloride, aluminum oxychloride, titanium tetrachloride, titanium trichloride, titanium oxychloride, tetraalkoxy titanates, tetraalkoxy silicates, cyclic or acyclic siloxanes, silicon tetrachloride, trichlorosilane, methyltrichlorosilane, dichlorosilane, monochlorosilane, or mixtures thereof.
7. The method according to any one of claims 1 to 6, wherein the first heat transfer medium is water.
8. 8. The method according to any one of claims 2 to 7, wherein the second heat transfer medium is selected from hydrocarbons having up to 6 carbon atoms such as propane, cyclopropane, butane, isobutane, pentane, cyclopentane, hexane, and halogenated hydrocarbons, and mixtures thereof.
9. The method of any one of claims 2 to 8, wherein the expansion device is an expansion turbine.
10. 10. The method of any one of claims 1 to 9, wherein at least a portion of the first heat transfer medium is used for one or more of the following: heating the metal precursor and / or metalloid precursor prior to use in step (a) of the method; heating at least one gas prior to use in step (a) of the method.
11. At least a portion of the electrical energy produced by the method comprises: obtaining hydrogen from the electrolysis of water or an aqueous solution and using at least a portion of this hydrogen in step (a) of the process; - heating the metal and / or metalloid precursors before use in step (a) of the method, - heating at least one gas prior to use in step (a) of the method; - powering at least one pump used in said method; used for one or more of The method according to any one of claims 2 to 9.
12. said metal oxide or said metalloid oxide is selected from oxides of aluminum (Al), titanium (Ti) and silicon (Si); at least a portion of said first heat transfer medium is: o heating the metal precursor and / or the metalloid precursor prior to use in step (a) of the method; heating at least one gas prior to use in step (a) of the method; used for one or more of The method according to any one of claims 1 to 11.
13. said metal oxides and / or semi-metal oxides are selected from oxides of aluminum (Al), titanium (Ti) and silicon (Si); At least part of the electrical energy produced by the method is: obtaining hydrogen from the electrolysis of water or an aqueous solution and using at least a portion of this hydrogen in step (a) of the process; o heating the metal or metalloid precursor prior to use in step (a) of the method; o heating at least one gas prior to use in step (a) of the method; o powering at least one pump used in the method; used for one or more of The method according to any one of claims 2 to 11.
14. 14. The method according to any one of claims 1 to 13, wherein oxygen is obtained from the electrolysis of water or an aqueous solution using electrical energy obtained at least in part from a renewable energy source, and at least a portion of this oxygen is used in step (a) of the method.