Electrochemical Synthesis of Low-Carbon Cement

Cement is responsible for 8% of global CO2 emissions. Currently, the only economical way to make Portland cement’s key ingredient, lime, is by thermally decomposing limestone. This reaction contributes ~75% of cement’s emissions. Sublime Systems (Sublime) will build an electrochemical system to produce lime using off-peak renewable electricity and calcium sources that do not release CO2. The lime produced may possess exceptional purity, consistency, and reactivity, enabling next-generation low-carbon cements. If successful and scaled, Sublime’s electrochemical synthesis of lime would reduce energy-related emissions in the U.S. from lime and cement making while simultaneously providing ancillary grid services, enabling proliferation of renewables.