The cement industry in the search for net zero CO2 emissions

The opportunity to use CO2 in the concrete mix

The cement and concrete industry represents 7 % of global CO2 emissions (reference) due to the chemical reaction required for the production of cement and by the energy required in the process.

For these reasons, this industry is part of many in the search for the net zero balance of CO2 emissions. One of several options is the injection of CO2 into the prepared concrete mixture to improve compressive strength.

CO2 capture process for use in the concrete mix

The process, summarized in the following image, consists of capturing CO2 from an inexhaustible source such as the atmosphere, to produce a mixture mostly of CO2 and water. The mixture is first purified to obtain a stream with more than 99% vol of CO2 and then liquefied at low temperature and high pressure to facilitate storage and subsequent transport.

The process in question takes advantage of the heat of exhaust gases to produce steam that is used in the CO2 capture process; this increases the overall energy efficiency of the process.

The wastewater from the capture and purification processes of CO2 is treated and reused for the generation of steam, further improving efficiency.

Algunas tecnologías con el uso de CO2 en la mezcla de concreto, permiten capturar 15 kg de CO2 por metro cúbico de concreto.