Researchers have developed a new cement-making process that could potentially create a carbon-negative version of the building material. Cement production is a major contributor to global carbon dioxide emissions, responsible for about 8 percent of total CO2 emissions worldwide. Traditional cement production involves mining for raw materials for concrete, resulting in significant carbon emissions. To combat this issue, researchers from Northwestern University partnered with cement manufacturer Cemex’s innovation development branch to develop a more sustainable cement-making process.
The team utilized seawater electrolysis, a technique that involves zapping seawater with electricity to split its molecules. This process generates hydrogen gas, chlorine gas, and oxygen, as well as minerals such as calcium carbonate, which is the primary raw material for cement production. While previous researchers using seawater electrolysis for hydrogen gas production considered the precipitated minerals an annoyance, this team saw potential for the minerals to be used in sustainable cement production.
The rate of mineral production through electrolysis is currently too slow to meet industrial demand, prompting the researchers to investigate how to expedite the process and increase the yield. Through laboratory experiments, they inserted electrodes into seawater, adjusted the applied voltage, and injected carbon dioxide gas into the water at different rates and volumes to fine-tune the water’s pH. By varying these factors, they were able to change the volumes, chemical compositions, and crystal structures of the minerals being precipitated.
The experiments revealed that it is possible to tailor seawater electrolysis to produce a variety of minerals and aggregates that could be used in the construction industry. If the energy source for the electricity used in this process is renewable, these materials could not only be carbon-neutral but carbon-negative – effectively trapping some of the atmosphere’s carbon dioxide for up to thousands of years. This innovative approach has the potential to revolutionize cement production and significantly reduce its environmental impact.
By shifting towards a carbon-negative cement-making process, the construction industry could play a crucial role in combating climate change. The ability to sequester carbon dioxide through sustainable mineral production offers a promising solution to reducing greenhouse gas emissions associated with traditional cement production. Further research and development in this area could lead to the widespread adoption of greener building materials that have a positive impact on the environment.
Overall, the research demonstrates the potential for applying innovative technologies to transform a high-emission industry such as cement production into a more sustainable and environmentally friendly sector. With continued advancements in this field, it is possible to mitigate the environmental impact of construction materials and contribute to global efforts to address climate change.
