„ZeroCAL“-Zementproduktionsprozess reduziert CO2 aus der Gleichung | Mit 98 % weniger CO2-Emissionen als herkömmliche Methoden durch Zersetzung von Kalkstein – dem wichtigsten Rohstoff bei der Herstellung von Zement – ​​um Kalziumoxid, auch Kalk genannt, zu gewinnen, ohne dass dabei Kohlendioxid freigesetzt wird.

From the article: [The team](https://pubs.acs.org/doi/10.1021/acssuschemeng.4c03193) is calling this method ZeroCAL, short for zero carbon lime. It’s a big deal because there’s a massive opportunity to reduce global greenhouse gas emissions. Traditionally, heating limestone in a kiln to produce lime results in 1 lb of CO2 emitted for every lb of cement produced.

ZeroCAL skips the aforementioned fossil-fuel powered process of heating limestone. Instead, it starts with dissolving the sedimentary rock feedstock in a water-based solution containing a common industrial acid. Next, calcium is separated via membrane nanofiltration. Finally, an electrochemical process is carried out to produce calcium hydroxide – a zero-carbon precursor for cement and lime production.

That goes beyond just reducing the emissions from processing limestone to just 1.5%. “It addresses the carbon emissions resulting from limestone’s decomposition while providing clean hydrogen and oxygen to heat the cement kiln,” notes team lead Gaurav Sant. “Second, it enables onsite decarbonization while making use of existing kilns and limestone feedstocks without having to build separate carbon-capture and storage facilities.”