The US startup electrifying cement production to reduce emissions

The clean tech startup greenifying cement production: US-based clean tech company Sublime Systems — which has raised USD 50 mn to date — is using electricity instead of carbon-intensive heating processes to produce cement, CNBC writes.

A quick lesson: Cement powder is produced by crushing raw materials including limestone and clay with ingredients such as iron and fly ash, which is then heated to about 1.4k Celsius in a cylindrical rotary kiln, according to The Portland Cement Association. The heating process in the global cement manufacturing industry conventionally relies on carbon-intensive energy sources, accounting for some 8% of the world’s total carbon emissions.

Enter electrolyzers: Sublime’s technology substitutes the industry's traditional fossil-fuel-intensive thermal calcination process with an electrochemical process relying on electrolyzers to produce cement from a number of calcium sources at room temperature, according to Business Wire. Sublime’s process avoids both the use of fossil fuels and the release of CO2 from limestone.

Decarbonized cement is more cost-effective than carbon capture and storage: Instead of investing in carbon capture and storage projects, cement producers should aim to produce net zero products in a bid to make green cement cost-competitive, according to The Engine’s CEO Katie Rae, which has invested in Sublime. “Producing decarbonized cement directly, rather than doing carbon capture, drives both energy efficiency and eventual cost parity,” Rae told CNBC. Siam Cement Group (SCG) is backing Sublime System because its cement production method avoids costly and complicated carbon storage incorporation, venture investor at SCG Timothy McCaffery told CNBC.

Interest in decarbonizing the construction sector is picking up regionally: Saudi Arabia’s investment firm Shurfah Holding Company and France’s Hoffman Green Cement signed a preliminary agreement earlier this month to design and produce low-carbon cement. In May, the UAE’s Quazar Investment Company and UK-based Graphene Innovations Manchester (GIM) signed an agreement to establish a UAE-based JV to develop and produce low-carbon, cement-free graphene-based concrete.