... 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-...
> 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.
> 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.
... 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
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.
> 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 :
> 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://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