Over its lifetime, #cement already removes ~43% of the CO₂ from its production through carbonation (currently ~1 GtCO₂/yr). So if CO₂ is injected into cement during production (i.e., lower carbon cement), is that considered additional carbon removal? 🤔
"The #cement industry alone accounts for nearly eight percent of human-caused CO2 #emissions.
The Cambridge researchers approached the problem by looking at an industry that was already well established—steel recycling, which uses electric-powered furnaces to produce the alloy.
Instead of waste being produced, the end result was recycled cement ready for use in #concrete, bypassing the emissions-heavy process of superheating limestone in kilns."
" An electric arc furnace needs a "flux" material, usually lime, to purify the steel. At the end of the process, the used flux is discarded as a waste material. So for the Cambridge method, the lime flux was swapped out for the recycled #cement paste. And sure enough, not only was it able to purify the steel just fine, but if the leftover slag is cooled quickly in air, it becomes new Portland cement. "
"A research group at RMIT University in Melbourne, Australia, found a way to replace 80% of the #cement in #concrete with a waste product from coal-fired power plants.
#FlyAsh is mainly comprised of silicon, oxygen, aluminum, iron, and calcium. By adding nano silica and hydrated lime to their fly ash, the RMIT team have successfully produced concrete with 65% and 80% replacement of cement."
"A mere 57 oil, gas, coal and #cement producers are directly linked to 80% of the world’s greenhouse gas #emissions since the 2016 Paris climate agreement, a study has shown.
This powerful cohort of state-controlled corporations and shareholder-owned multinationals are the leading drivers of the #climate crisis
The most striking trend, however, was the surging growth of emissions related to state and state-owned producers, particularly in the Asian #coal sector."
A mere 57 oil, gas, coal and cement producers are directly linked to 80% of the world’s greenhouse gas emissions since the 2016 Paris climate agreement, a study by Carbon Majors Database has shown.
In the database of 122 of the world’s biggest historical climate polluters, the researchers found that 65% of state entities and 55% of private-sector companies had scaled up production. #ClimateEmergency#Oil#Gas#Cement#FossilFuels
An MNC is the target of a civil claim for its role in #climateChange. It is #Holcim (which bought Lafarge in 2015, just after the bribes to the terrorist organisation "Islamic State").
The Cantonal Court of Zug has ruled "that the court costs and lawyers' fees will be borne by the State."
"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?
"#Cement, #steel and #chemicals are some of the most extensively produced materials in the world. They’re also among the largest global sources of #CarbonEmissions — manufacturing them releases more CO2 into the atmosphere each year than all of the emissions generated by the United States.
These materials are so emissions-intensive not just because of how they’re made, but also because of how much of them the world uses."
"The #EuropeanUnion launched on Sunday the first phase of the world's first system to impose CO2 #EmissionsTariffs on imported #steel, #cement and other goods as it tries to stop more polluting foreign products from undermining its green transition."
But also:
"The bloc will not begin collecting any CO2 emission charges at the border until 2026."
What are they scared of?
UK breakthrough could slash emissions from cement (lighthouse-eco.co.za)
Scientists say they’ve found a way to recycle cement from demolished concrete buildings.
Prickly paddy melon weed enzymes show potential as sustainable cement alternative (lighthouse-eco.co.za)
A world-first study has found enzymes from the prickly paddy melon weed can create a sustainable alternative to cement.