Reflective Hollow SRM Material and Methods
20230249821 · 2023-08-10
Inventors
Cpc classification
B64D1/16
PERFORMING OPERATIONS; TRANSPORTING
Y02P60/20
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
B64D1/08
PERFORMING OPERATIONS; TRANSPORTING
International classification
B64D1/08
PERFORMING OPERATIONS; TRANSPORTING
B64D1/16
PERFORMING OPERATIONS; TRANSPORTING
Abstract
Methods of geoengineering are provided to create shade by reflecting solar radiation into space to mitigate global warming, as well as reduce storm severity, and other applications. These methods rely on dispersing hollow silicate microspheres into the atmosphere, or into orbit, by aircraft or rocket, where the silicate microspheres can optionally comprise additions of one of boron or sodium, or both. Silicate microspheres manufactured on the Moon can be delivered to Earth or L1 orbit as an alternative to lofting from Earth’s surface. Hollow silicate microspheres are more than 6 times the size of comparable solid SRM particles. This method substantially improves reflectivity, solar-powered lofting, and, in the presence of liquid water aerosols, the greater surface area enables improved carbon dioxide capture.
Claims
1. A method of geoengineering comprising: providing a rocket or aircraft with at least one containment vessel including a plurality of hollow silicate glass microspheres sized greater than 10 microns and less than about 100 microns in diameter and having a specific reflectivity greater than about 3.5; using the rocket or aircraft to deliver the containment vessel into a low Earth orbit, the orbit being from about 250 kilometers to about 2000 kilometers high, or using the rocket to deliver the containment vessel to a solar orbit between the sun and the Earth at the L1 point; and releasing the plurality of hollow glass silicate microspheres into the solar or low Earth orbit from the containment vessel.
2. The method of claim 1 wherein the silicate glass microspheres comprise a sodium silicate glass.
3. The method of claim 2 wherein the sodium silicate glass comprises greater than 16 percent sodium by weight.
4. The method of claim 3 wherein the sodium silicate glass includes more than about 20% sodium.
5. The method of claim 1 wherein the hollow interiors of the silicate glass microspheres are filled with a gas at a pressure below about 1 atm.
6. The method of claim 1 wherein the containment vessel further includes a dispersant.
7. The method of claim 6 wherein the dispersant comprises a gas.
8. The method of claim 6 wherein the dispersant comprises a fuel.
9. The method of claim 1 wherein releasing the plurality of hollow silicate glass microspheres into the solar or low Earth orbit includes electrostatically charging the plurality of hollow silicate glass microspheres.
10. The method of claim 1 wherein the low Earth orbit is between 40 degrees north latitude and 40 degrees south latitude.
11. The method of claim 1 further comprising manufacturing the hollow glass silicate microspheres comprising silicate minerals mined on the Moon or an asteroid.
12. A method of geoengineering comprising: providing an aircraft or rocket with at least one containment vessel including a plurality of hollow silicate glass microspheres sized greater than about 10 microns and less than about 100 microns in diameter and having a specific reflectivity greater than about 3.5; using the aircraft or rocket to deliver the containment vessel into the atmosphere; and releasing the plurality of hollow silicate glass microspheres into the atmosphere from the containment vessel.
13. The method of claim 12 wherein the silicate glass microspheres comprise a sodium silicate glass.
14. The method of claim 13 wherein releasing the plurality of hollow sodium silicate glass microspheres into the atmosphere is performed at an altitude ranging from about 10 kilometers to about 50 kilometers.
15. The method of claim 13 wherein the sodium silicate glass microspheres comprise at least 20% sodium.
16. The method of claim 15 wherein releasing the plurality of hollow silicate glass microspheres into the atmosphere is performed at an altitude ranging from about 100 meters to about 10,000 meters.
17. The method of claim 12 wherein the hollow interiors of the silicate glass microspheres are filled with a gas at a pressure below about 1 atm.
18. The method of claim 12 wherein the containment vessel further includes a dispersant.
19. The method of claim 18 wherein the dispersant comprises a gas.
20. The method of claim 18 wherein the dispersant comprises a fuel.
21. The method of claim 12 wherein releasing the plurality of hollow silicate glass microspheres into the atmosphere includes electrostatically charging the plurality of hollow silicate glass microspheres.
22. The method of claim 12 wherein releasing the plurality of hollow silicate glass microspheres into the atmosphere is performed between 40 degrees north latitude and 40 degrees south latitude.
23. The method of claim 12 wherein releasing the plurality of hollow silicate glass microspheres into the atmosphere includes releasing the plurality of hollow glass microspheres over a predicted tropical storm pathway.
24. A method of cloud seeding comprising: lofting a plurality of hollow glass microspheres sized greater than about 10 microns and less than about 100 microns in diameter and having a specific reflectivity greater than about 3.5; by mixing the plurality of hollow glass microspheres with a heated gas, and releasing the heated gas including the hollow glass microspheres into the atmosphere, wherein the air of the atmosphere is cooler that the heated gas.
25. The method of claim 24 wherein the heated gas including the hollow glass microspheres is released through a chimney or cooling tower.
26. The method of claim 24 wherein the silicate glass microspheres comprise a silicate glass including at least 20% sodium.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Preferred embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:
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[0035] Some embodiments are described in detail with reference to the related drawings. Additional embodiments, features, and/or advantages will become apparent from the ensuing description or may be learned by practicing the invention. In the illustrations, which are not drawn to scale, like numerals refer to like features throughout the description. The following description is not to be taken in a limiting sense but is made merely for describing the general principles of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0036] The following detailed description, taken in conjunction with the accompanying drawings, is merely exemplary in nature and is not intended to limit the described embodiments or the application and uses of the described embodiments. Any implementation described herein as “exemplary” or “illustrative” is not necessarily to be construed as preferred or advantageous over other implementations.
[0037] Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. It is also understood that the specific devices, systems, methods, and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims that there may be variations to the drawings, steps, methods, or processes, depicted therein without departing from the spirit of the invention. All these variations are within the scope of the present invention. Hence, specific structural and functional details disclosed in relation to the exemplary embodiments described herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present embodiments in virtually any appropriate form, and it will be apparent to those skilled in the art that the present invention may be practiced without these specific details.
[0038] Various terms used in the following detailed description are provided and included for giving a perspective understanding of the function, operation, and use of the present invention, and such terms are not intended to limit the embodiments, scope, claims, or use of the present invention.
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[0040] The dissolution rates for silicate glasses in seawater are temperature dependent and have been well characterized. All silicate glass compositions dissolve in seawater, as the ocean has a pH of 8.1. The caustic reaction with sodium in seawater will act to dissolve almost all silicate glass without boron within 1 month and within 5 months for borosilicate glass, since boron imparts some resistance to sodium corrosion in liquid water.
[0041] The glassy atomic structure of silicon dioxide is represented by the inset view 15. The silicate glass structure 16 has a multiplicity of silicon and oxygen bonds as denoted by the subscript (n). The silicate glass structure 16 has localized distortion of the bonds between the silicon (Si) and the oxygen (O) away from more regular lattice locations that are characteristic of amorphous silicon dioxide glass. The silicate glass structure 16 includes impurity metal cations such as sodium 18, represented by atomic symbol Na. Addition of sodium generates a soda glass that reacts with and then sequesters carbon dioxide (CO.sub.2) from the atmosphere, or reacts with carbonic acid when moisture is present. Sodium addition greater than 20% will minimize the lifetime of the soda glass particle when in contact with the air to maximize the remediation of CO.sub.2.
[0042] Borosilicate glass is an example of a suitable stable silicate glass for use in the high altitude where the boron is a glass corrosion inhibitor and will extend the lofted particle lifetime as a solar radiation reflector material or SRM. Borosilicate glass normally includes about 5% to about 13% boron trioxide (B.sub.2O.sub.3) by weight, where this impurity incorporation is indicated by the symbol B for boron 17. The corrosion rates for silicate glass, sodium silicate glass, and borosilicate glass in air are well known to be about 100 times less in humid air than on contact with liquid water. Glass corrosion may be desired when applied to clouds below the dew point temperature for carbon sequestration by sodium carbonate formation. However, it is to be understood that commonly, the term glass or the term silicate glass may be used to refer to all types of glass for the purpose of the present invention, regardless of the doping or impurity content. Commercial grades of borosilicate glass raw material have been well characterized and are able to be produced from well-known companies such as Pyrex, Duran, Potters Industries, and 3 M corporation. Borosilicate glasses have low coefficients of thermal expansion (CTE). Type 7740 Pyrex has a thermal expansion coefficient (CTE) of about one third that of a typical soda glass. Borosilicate glasses are, therefore, less subject to stress caused by thermal expansion and thus less vulnerable to cracking from thermal shock.
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[0049] For comparison, the solid black line 78 represents the experimental reflectance data of liquid water at all angles of light incidence that are less than about 85 degrees. Pure liquid water is substantially absorbing solar radiations at most visible and infrared frequencies, having only a trace of reflectance being no greater than about 4 percent at the 550 \-nanometer solar maximum irradiance output. Pure crystalline silicate sand is shown by dotted line 76.
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[0052] The resulting coated region 95 on the exterior surface of the glass microspheres 90 are preferably a dark color, such as is obtained by carbon black or graphite, and is added to absorb solar radiation, thereby producing a heated area that makes air in the vicinity rise to produce lift, where the lift force is indicated by the upward direction of the solid black the arrow 96. The production of lift on the glass microsphere during hours of solar illuminance serves to increase the microsphere lofted altitude as well as to increase the microsphere residence or lifetime. This process is termed “solar powered lofting” and saves considerably in the deployment altitude, since the microspheres will automatically migrate to higher altitudes. One suitable material for a solar powered lofting coating 95 is soot, or amorphous black carbon, that can be deposited at or near room temperature in a gas vapor. The coating 95 can also be a graphitic coating when the deposition temperature is about 550° C., and the deposit process is at a reduced pressure or less than about 12 torr.
[0053] Other types of coatings 95 can be substituted or added to any portion of the microspheres 90 by use of the deposition method, for instance, a stabilizing zinc indium sulfide (ZnIn.sub.2S.sub.4) catalyst. This material is already in ground-level commercial use for some types of CO.sub.2 electroreduction to formic acid or sodium formate. This or a similar chemical process allows carbon sequestration to take place at the surface of the glass microsphere 90 when exposed to liquid water. The presence of highly charged cloud layers enables chemical reactivity as one way to perform gaseous carbon dioxide sequestration. The silicate glass microsphere 90 may optionally consist of a soda-glass or sodium containing silicate glass, where the alkali chemistry of the glass is able to react with gaseous CO.sub.2, or water borne carbonic acid, to form sodium bicarbonate, which forms at the surface of the glass microsphere in contact with liquid water.
[0054] In addition, the particle sizes of at least six times greater than the presently known 14-micron average of particles found at altitude overcomes previous SRMs limited by high density and solid mass. The hollow microsphere SRM particle configuration significantly promotes greater reflectivity, and greater service life in the air, as compared to well-known simulation results obtained using high-density solid particle structures. Solar powered particle lift becomes greatly enabled using large hollow particles of low density, just as greater aircraft wing area acts to increase lift for conventional air powered transportation. Finally, solar powered lofting creates long atmospheric residence lifetimes that significantly reduce or eliminate the risk of deployment termination shock to the global climate, should the atmospheric placement or replacement SRM happen to stop for any unforeseeable reason. These specific examples are meant to be representative but non-limiting methods of coating hollow glass microspheres for solar radiation management, carbon sequestration by fixing or reacting with CO.sub.2, or both sequestration and SRM with optional solar powered lofting. Any of these methods of coating are part of the reduced density and SRM objectives when used in accordance with the intent of the present invention.
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[0056] In step S102, the SRM release method is determined. In some embodiments the most economic method or the desired rate of release method is selected. For example, one way to avoid air transport costs is to release the self-lofting hollow silicate microspheres from the ground is by means of a hot air discharge such as from an upward directed air flow from a smokestack, cooling tower, or chimney. The self-lofting microspheres can also be delivered at 12 to 20 kilometers altitude by aircraft (e.g., drones, balloons, airplanes, etc.) where they can use solar powered lofting to rise to 80 kilometers in altitude for extended periods of time. Alternatively, and especially in Earth orbit, a rocket can be used for microsphere SRM release, as described above.
[0057] In step S103, the self-lofting silicate microspheres are released at an altitude of about 12 to about 20 kilometers. The methods described above for release from containment vessels, including the use of a dispersant and the use of electrostatic charging of the microspheres, apply equally to embodiments employing coated microspheres. It is noted that electrostatic charging can be useful to attract moisture to initiate rainfall. It is furthermore noted that electrostatic charging provided by wind friction or solar charged particles is useful to activate electrocatalysis and chemical conversion of carbon dioxide into substances that precipitate from the atmosphere.
[0058] In step S104 solar radiation heats the darkened regions of the hollow glass microspheres to enable the self-lofting function so that the microspheres will ascend to at least 50 kilometers to perform solar radiation management, while being able to persist at such altitude because of their low density.
[0059] It is understood that the orbital placement or the atmospherically lofted reflective hollow borosilicate glass microspheres deployed in accordance with this method, have a finite and decaying lifetime, as well as a useful but limited product duty period. Once the orbital or elevated service period has reached its limit, the individual microspheres will fall to lower levels, and finally descend to the planet to become disposed at the surface. At this point, the materials of the silicate microspheres are returned to both land surfaces and ocean surfaces, where they will temporarily continue to reflect solar radiation before becoming covered by less reflective materials or dissolving and then sinking to the ocean depths as their closed hollow interiors become open to fill with seawater.
[0060] As variations, combinations and modifications may be made in the construction and methods herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments but defined in accordance with the foregoing claims appended hereto and their equivalents.