3 ms·

Toward electrochemical synthesis of cement–An electrolyzer-based process

3 points by westurner 2y ago

westurner 2y ago
... Learned of this via "Electrochemistry Might Help Solve Cement’s Carbon Problem" which describes Portland cement production methods in general and also Sublime Systems' electrochemical synthesis efficiency and sustainability advantages: https://cleantechnica.com/2024/05/23/electrochemistry-might-help-solve-cements-carbon-problem/ https://cleantechnica.com/2024/05/23/electrochemistry-might-... > In fact, all of the heat can be electrified too, and has been both historically and in demonstration units today. Electric heat for the limestone kiln is a relatively trivial thing to build into new kilns, although more challenging to retrofit to existing ones. And from the paper, "Toward electrochemical synthesis of cement—An electrolyzer-based process for decarbonating CaCO3 while producing useful gas streams" (2019) https://www.pnas.org/doi/10.1073/pnas.1821673116 https://www.pnas.org/doi/10.1073/pnas.1821673116 : > Electrochemical calcination produces concentrated gas streams from which CO2 may be readily separated and sequestered, H2 and/or O2 may be used to generate electric power via fuel cells or combustors, O2 may be used as a component of oxyfuel in the cement kiln to improve efficiency and lower CO2 emissions, or the output gases may be used for other value-added processes such as liquid fuel production. Analysis shows that if the hydrogen produced by the reactor were combusted to heat the high-temperature kiln, the electrochemical cement process could be powered solely by renewable electricity. Could probably get it started with sunlight: > "Solar thermal trapping at 1,000°C and above" (2024) https://www.cell.com/device/fulltext/S2666-9986(24)00235-7 https://www.cell.com/device/fulltext/S2666-9986(24)00235-7 https://news.ycombinator.com/item?id=40419777 https://news.ycombinator.com/item?id=40419777 ... Concrete can be more sustainable and efficient. Concrete may or may not be a better thermal battery than gravel. Other things concrete fwiw: - Roman Concrete was made with volcanic ash - Uncoated steel rebar rusts in less than 100 years FWIU? - Concrete block is easier to repair than large, interlocking slabs - Plant-based blocks can be cut with a handsaw - (Catalan) brick vault roofs do not require forms or support; and round structures handle wind and storms best - Hempcrete is made with Lime, too - Sugarcrete is made with Sugarcane and sand - Bio-based block breathes with relative humidity - Higher R-Value, higher strength construction materials reduce HVAC and post-disaster reconstruction costs - (sinusoidal) wavy walls need only be one brick wide - Dry stone walls of e.g. Peru, which may be made with geopolymers; have irregularly-shaped blocks, that are locked together, and settle down into V's for earthquake resilience. - There are new like infinitely repeating tile shapes that may or may not be as easy to form as bricks
- pestatije 2y ago
  one thing is the energy required and another one the chemical reaction itself
  - westurner 2y ago
    endothermic and/or exothermic; in an open system with or without constant volume
    - westurner 2y ago
      When prompted re: ancient methods including low voltage and concrete, gemini suggested that low voltage heat in a drying geopolymer / concrete would dry it and prevent cracking.

3 points by westurner 2y ago

... Learned of this via "Electrochemistry Might Help Solve Cement’s Carbon Problem" which describes Portland cement production methods in general and also Sublime Systems' electrochemical synthesis efficiency and sustainability advantages: https://cleantechnica.com/2024/05/23/electrochemistry-might-help-solve-cements-carbon-problem/ https://cleantechnica.com/2024/05/23/electrochemistry-might-... > In fact, all of the heat can be electrified too, and has been both historically and in demonstration units today. Electric heat for the limestone kiln is a relatively trivial thing to build into new kilns, although more challenging to retrofit to existing ones. And from the paper, "Toward electrochemical synthesis of cement—An electrolyzer-based process for decarbonating CaCO3 while producing useful gas streams" (2019) https://www.pnas.org/doi/10.1073/pnas.1821673116 https://www.pnas.org/doi/10.1073/pnas.1821673116 : > Electrochemical calcination produces concentrated gas streams from which CO2 may be readily separated and sequestered, H2 and/or O2 may be used to generate electric power via fuel cells or combustors, O2 may be used as a component of oxyfuel in the cement kiln to improve efficiency and lower CO2 emissions, or the output gases may be used for other value-added processes such as liquid fuel production. Analysis shows that if the hydrogen produced by the reactor were combusted to heat the high-temperature kiln, the electrochemical cement process could be powered solely by renewable electricity. Could probably get it started with sunlight: > "Solar thermal trapping at 1,000°C and above" (2024) https://www.cell.com/device/fulltext/S2666-9986(24)00235-7 https://www.cell.com/device/fulltext/S2666-9986(24)00235-7 https://news.ycombinator.com/item?id=40419777 https://news.ycombinator.com/item?id=40419777 ... Concrete can be more sustainable and efficient. Concrete may or may not be a better thermal battery than gravel. Other things concrete fwiw: - Roman Concrete was made with volcanic ash - Uncoated steel rebar rusts in less than 100 years FWIU? - Concrete block is easier to repair than large, interlocking slabs - Plant-based blocks can be cut with a handsaw - (Catalan) brick vault roofs do not require forms or support; and round structures handle wind and storms best - Hempcrete is made with Lime, too - Sugarcrete is made with Sugarcane and sand - Bio-based block breathes with relative humidity - Higher R-Value, higher strength construction materials reduce HVAC and post-disaster reconstruction costs - (sinusoidal) wavy walls need only be one brick wide - Dry stone walls of e.g. Peru, which may be made with geopolymers; have irregularly-shaped blocks, that are locked together, and settle down into V's for earthquake resilience. - There are new like infinitely repeating tile shapes that may or may not be as easy to form as bricks

pestatije 2y ago
one thing is the energy required and another one the chemical reaction itself
- westurner 2y ago
  endothermic and/or exothermic; in an open system with or without constant volume
  - westurner 2y ago
    When prompted re: ancient methods including low voltage and concrete, gemini suggested that low voltage heat in a drying geopolymer / concrete would dry it and prevent cracking.