Brendan Jones
"A Massachusetts-based startup has figured out how to produce zero-carbon cement."
This sounds amazing and it's huge if it can be scaled (cement production currently causes 8% of global carbon emissions), but the article is basically an uncritical press release.
Anyone familiar with the subject: what are the downsides, if any?
https://heatmap.news/technology/sublime-carbon-cement-electrolyzer #climatechange #emissions #concrete #cement
Brendan Jones
For example, I'm curious if the feed materials are commonly and sustainably available, not that they're very open about what materials they're using.
"One electrode produces a solution that extracts calcium from inert minerals, leaving behind a reactive silicate. The second electrode produces alkalinity, which precipitates calcium (also known as lime) as a pure, reactive solid."
Brendan Jones
@accretionist yes indeed, it won't be cost competitive yet. It'd be interesting to see their projections for when they could be.
accretionist
"And third, the technology Sublime uses to drive its chemical process — a device called an electrolyzer — has become much cheaper. Though electrolyzers have been around for a long time, they’ve recently benefited from increased economies of scale as interest in using them for applications like clean hydrogen production has grown."
sounds like it's driven by electricity, so the issue would be cost. there's a lot of grinding and heating in cement production. it's easy and cheap to throw fossil fuels at that. i hope they're able to get their process near enough to be economically competitive
Brendan Jones
@NatureMC Their website it quite minimal but there's way more info about the process in this article. It's actually a fascinating and educational interview, I can recommend giving the whole thing a listen/read: https://www.volts.wtf/p/we-are-closing-in-on-zero-carbon
Petra van Cronenburg
@Brendanjones They use "rocks and industrial waste", so they take at least a large part from nature.
In the last months I found at least 3 "very new methods" to produce what they promise. I never found an independent (!) article/study of all these startups that it works in real life, in great scale.
I'm not a specialist but it sounds like the phase to find investors and get a break-through.
Brendan Jones
I went searching, to answer my own questions. A lot of this is answered in this excellent interview: https://www.volts.wtf/p/we-are-closing-in-on-zero-carbon
Brendan Jones
@accretionist on cost: "So 80% of the total installed cost of concrete is labor, and it's often unionized labor.
The cement is 10% of that, and the aggregate is the remaining 10% so even if we were to charge a two to four x green premium, really, it doesn't really affect the overall cost of a building that much."
from https://www.volts.wtf/p/we-are-closing-in-on-zero-carbon. Really interesting read, actually.
accretionist
@Brendanjones it's still worth it for niche use cases
they want to have bases on the moon- what would it take to turn lunar soil into cement? can't put a natural gas powered kiln on the moon, but you can get electricity from the sun. might be a nice funding angle to master the technology, then bring it back to earth
Brendan Jones
@NatureMC "nobody can produce alternatives on an industrial level" indeed, Sublime included. I too am casting a skeptical eye at this. But it is promising that they have an actual plant in the works to test it at scale, so it's not *all* talk.
Petra van Cronenburg
@Brendanjones Unfortunately, I have no time to read the whole interview, I could only skim it. She's great in public relations. When things get interesting, she dodges the question and talks about "great stuff". She talks about basalt rocks (which ones), about bottom ash (others use that, too). She talks of calcium silicate that they use but not how it differs from industry (sometimes it comes from slag and that's absolutely not carbon-neutral).
I found this https://en.wikipedia.org/wiki/Cement_chemist_notation
Petra van Cronenburg
@Brendanjones Well, if you search for carbon zero cement etc. you find many links and nobody can produce alternatives on an industrial level or they hide parts of carbon elsewhere. Even McKinsey ! writes that change hasn't yet arrived on an industrial scale, that it's everything still in experimentation.
And there are many experiments like algae cement: https://www.popularmechanics.com/science/green-tech/a40785162/microalgae-carbon-neutral-cement/
To put it bluntly: I am fascinated by such approaches. I'm just extremely sceptical because I can't find anything about
Brendan Jones
@hobs to be fair she does answer a bunch of what you asked.
Hobson Lane
@Brendanjones
That interview with CEO is sales not analysis. No reason to believe any claims. Obstacles that remain before making it economically, environmentally *and* mechanically sustainable? Material properties? How do properties change with wear, weather, and stress? Has it been vibe/earthquake/life tested? How much more expensive will the first batch be? What is its price/strength/life right now, out of the lab? Why isn't it selling itself?
GNU social JP is a social network, courtesy of GNU social JP管理人. It runs on GNU social, version 2.0.2-dev, available under the GNU Affero General Public License.
All GNU social JP content and data are available under the Creative Commons Attribution 3.0 license.