A Concrete Plan for Sustainable Cement Production | Ryan Gilliam | TED

The Cement Emissions Problem

• cement is the second most-consumed substance globally, second only to water.
• cement production accounts for approximately eight percent of global CO2 emissions, placing it third globally if it were a country.
• The primary source of CO2 in cement production is limestone, which is 44 percent CO2 by weight.

Nature's Inspiration for Cement

• Early inspiration came from Calera, a company that observed how nature forms building blocks like coral reefs and shells.
• In nature, CO2 is absorbed in the ocean to create reactive limestone structures (vaterite), which then cement when water is added.
• This natural process demonstrated that CO2 could be transformed into a product rather than being a waste emission.

Economic and Technical Challenges

• While technically feasible, early attempts like Calera's were not economically viable within the existing cement industry.
• The cement industry is risk-averse due to the critical need for performance and safety in construction.
• Any solution must leverage existing infrastructure, feedstocks, and regulations to be cost-effective and scalable.

A Sustainable Cement Solution

• The company Forterra integrates CO2 capture technology into existing cement kilns.
• By capturing CO2 and combining it with lime produced from limestone, they create a product that can be blended with or replace traditional cement.
• This process doubles the product output and makes it economically competitive without a green premium.
• This approach can reduce CO2 emissions by 70 percent per ton of cement, with the potential for zero emissions when integrated with clean energy.

Scaling and Global Impact

• Forterra's strategy focuses on bolting onto existing plants and working with major cement players to achieve scale and cost efficiency.
• Their first commercial plant in Northern California, operational in early 2024, validates this approach.
• The goal is to scale globally, achieving gigaton reductions in CO2 emissions by making zero-CO2 cement a reality.