US: Researchers at UCLA's Institute for Carbon Management have developed a new method called ZeroCAL that could eliminate ‘nearly all’ of the carbon dioxide emissions from the process of cement production, according to the UCLA Newsroom. The team created a process using limestone and a water-based solution containing ethylenediaminetetraacetic acid. Through membrane nanofiltration and an electrochemical process, they produced calcium hydroxide.
To meet ZeroCAL’s water demand, the team suggests focusing on cement plants near coasts or rivers. The researchers are reportedly working with Ultratech Cement to build a demonstration plant that will produce ‘several’ tonnes of lime per day using the ZeroCAL process. Currently, the process requires more energy than traditional lime production methods, but ongoing research aims to reduce its energy consumption.
Gaurav Sant, director of the Institute and professor at UCLA Samueli School of Engineering, said “The ZeroCAL approach offers an elegant solution to eliminate carbon dioxide emissions associated with the process of cement production. First, it addresses the carbon emissions resulting from limestone’s decomposition while providing clean hydrogen and oxygen to heat the cement kiln. Second, it enables onsite decarbonisation while making use of existing kilns and limestone feedstocks without having to build separate carbon capture and storage facilities.”