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US-20260125320-A1 - Carbon-Sequestering Concrete Composition with Enhanced CO2 Absorption and Method of Manufacturing Thereof

US20260125320A1US 20260125320 A1US20260125320 A1US 20260125320A1US-20260125320-A1

Abstract

A carbon-sequestering concrete composition and method of production are disclosed. The composition comprises geopolymer binder components, aggregates, and alginate beads formed from brown algae powder through ionic gelation. The alginate beads significantly increase CO2 absorption surface area compared to algae powder, creating a matrix across the concrete surface that enhances long-term sequestration and improves durability. The beads interact synergistically with other concrete components, including geopolymers, fly ash, and ground granulated blast furnace slag, to enhance pozzolanic reactions and create additional sites for carbon dioxide capture. The alginate beads also facilitate the dissolution of minerals like olivine, further enhancing carbon capture. The composition demonstrates superior carbon sequestration capabilities, enabling sustained CO2 absorption throughout its service life. The method includes forming alginate beads, incorporating them into the concrete mixture, and allowing for initial hardening and drying processes that promote carbon dioxide absorption directly from the air.

Inventors

  • Michael R. Lafave

Assignees

  • Michael R. Lafave

Dates

Publication Date
20260507
Application Date
20251229

Claims (20)

  1. 1 . A carbon-sequestering concrete composition comprising: 35-50% geopolymers comprising at least one of ground granulated blast furnace slag, class C fly ash, class F fly ash, metakaolin, or silica fume; 30-45% sand; 15-25% coarse aggregates comprising gravel or crushed stone; 5-10% water; and 1-5% dried marine algae powder.
  2. 2 . The composition of claim 1 , wherein the geopolymers comprise ground granulated blast furnace slag and metakaolin.
  3. 3 . The composition of claim 1 , wherein the geopolymers comprise class C fly ash.
  4. 4 . The composition of claim 1 , wherein the geopolymers comprise class F fly ash blended with at least one of ground granulated blast furnace slag, class C fly ash, metakaolin, or silica fume.
  5. 5 . The composition of claim 1 , wherein the sand has a particle size of less than 2.5 mm and angular crushed particles with semi-angular shapes.
  6. 6 . The composition of claim 1 , wherein the coarse aggregates have particle sizes ranging from 4 mm to 20 mm.
  7. 7 . The composition of claim 1 , wherein the dried marine algae powder comprises species from red and brown algae groups.
  8. 8 . The composition of claim 7 , wherein the dried marine algae powder comprises at least one of Laminaria, Ascophyllum, Sargassum, and Fucus species.
  9. 9 . The composition of claim 1 further comprising interground limestone powder incorporated into the geopolymer binder at a ratio of 5-15% by weight.
  10. 10 . The composition of claim 9 wherein the interground limestone powder has a particle size less than 100 microns.
  11. 11 . The composition of claim 9 wherein incorporation of the interground limestone powder provides abundant calcium oxide reactivity throughout the binder matrix to facilitate additional carbon dioxide absorption during curing.
  12. 12 . The composition of claim 1 wherein the coarse aggregates comprise dolomitic sand to contribute reactive magnesium oxide and calcium oxide to the geopolymer matrix upon dissolution, thereby providing additional carbon dioxide absorption capacity.
  13. 13 . A sidewalk comprising the carbon-sequestering concrete of claim 1 .
  14. 14 . The sidewalk of claim 13 , having a thickness of 4 inches.
  15. 15 . The sidewalk of claim 13 , wherein the concrete has a freeze-thaw resilience to withstand winter conditions during its service lifetime.
  16. 16 . The sidewalk of claim 13 , configured to sequester carbon dioxide from the atmosphere over a service lifetime of at least 50 years.
  17. 17 . The sidewalk of claim 16 , configured to sequester up to 30 lbs of carbon dioxide per cubic yard of the concrete over the service lifetime.
  18. 18 . The sidewalk of claim 13 , wherein widescale adoption of the sidewalk enables cumulative removal of over 120 million tons of carbon dioxide from the atmosphere.
  19. 19 . The sidewalk of claim 13 , configured for construction using existing pouring and finishing equipment for pedestrian infrastructure.
  20. 20 . A sidewalk comprising: a geopolymer-algae concrete slab having a thickness of 4 inches; wherein the slab is configured to sequester up to 30 lbs carbon dioxide per cubic yard of concrete over a 50 year service lifetime.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and incorporates by reference in its entirety U.S. Provisional Ser. No. 63/469,108 , filed May 26, 2023, and U.S. Nonprovisional application Ser. No. 18/909,669, filed Oct. 8, 2024, which are incorporated herein by reference in its entirety. This application also claims the benefit of, is a continuation-in-part of, and incorporates by reference in its entirety U.S. patent application Ser. No. 18/722,678, filed on Jun. 21, 2024, and U.S. patent application Ser. No. 18/814,312 filed on Aug. 23, 2024. This application also claims the benefit of and incorporates by reference in its entirety International Patent Application No. PCT/US24/13913, filed Feb. 1, 2024. FIELD OF THE INVENTION The present invention relates to the field of sustainable construction materials, specifically to carbon-sequestering concrete compositions and methods for their production. BACKGROUND OF THE INVENTION Concrete is one of the most widely used construction materials globally, with over 4 billion metric tons produced annually. However, conventional Portland cement concrete production is a significant contributor to global carbon dioxide emissions, accounting for 7-8% of all CO2 emissions worldwide. This represents an immense environmental burden, generating over 2 gigatons of carbon dioxide per year during cement production alone. Recent efforts to mitigate the carbon footprint of concrete have explored various approaches, including the incorporation of seawater and algae into concrete mixes to enable CO2 sequestration. However, these existing methods have achieved only modest and inconsistent levels of CO2 absorption that pale in comparison to the scale of emissions from concrete production. One such approach is described in Korean U.S. Pat. No. 102,079,643 B1 to Lee et al. (“LEE”), which discloses a carbon dioxide-absorbing marine concrete composition made by mixing blast furnace slag, fly ash, metakaolin, sodium silicate, and dried algae powder. While this composition attempts to address the environmental impact of concrete production, it suffers from several significant limitations. The use of algae powder alone in the manner disclosed by LEE fails to fully leverage the carbon sequestration potential of marine algae, as it does not provide optimal surface area for CO2 absorption or create the necessary conditions for long-term carbon mineralization. Furthermore, simply mixing algae powder into concrete does not facilitate the formation of a matrix across the concrete surface that could enhance long-term sequestration and improve durability. There is a need for an innovative approach that can dramatically increase the CO2 absorption capacity of concrete, create synergistic interactions with other concrete components, and provide a mechanism for moisture retention to facilitate greater direct air capture of CO2. Such an approach would overcome the limitations of current algae-based concrete technologies and offer superior CO2 sequestration capabilities, enhanced durability, and improved overall performance. The need for carbon-capturing concrete has become increasingly urgent as the construction industry seeks to reduce its significant carbon footprint. To incentivize the adoption of such environmentally beneficial technologies, various tax credits and incentives have been established. Section 45Q of the Internal Revenue Code provides tax credits for carbon oxide sequestration, which can result in substantial savings for concrete producers utilizing this technology. Additionally, the Investment Tax Credit offers up to 30% credit on capital investments in carbon-capturing technologies. Other applicable incentives include R&D tax credits, Production Tax Credits, and various federal and state tax incentives designed to promote sustainable construction practices. These financial incentives not only make the adoption of carbon-sequestering concrete more economically viable but also align with broader policy goals of reducing greenhouse gas emissions and promoting sustainable development in the construction industry. These limitations result in a concrete composition that, while attempting to address environmental concerns, falls short of achieving significant and long-lasting carbon sequestration. The present invention seeks to overcome these limitations by providing a novel carbon-absorbing concrete composition and method of production that offers superior CO2 sequestration capabilities, enhanced durability, and improved overall performance compared to existing technologies. SUMMARY OF THE INVENTION The present invention relates to a carbon-sequestering concrete composition and method of production that addresses the limitations of previous approaches to reducing the carbon footprint of concrete. At the core of the preferred embodiment is the utilization of brown algae species, particularly “macrocystis pyrifera”, which are transformed into alginate beads th