Cement's production high environmental footprint

The production of cement results in more pollution in the environment than all the trucks and just 1% less than all the cars worldwide.

Nowadays most engineers and designers are focusing on reducing the carbon footprint of already constructed buildings and their efforts have indeed been productive. However, it is the building production which incorporates chemical reactions that highly affect the environment.

In particular, according to data from 2017, steel, trucks, cement production and cars account for 5.1%, 6.1%, 6.9% and 7.9% of the total carbon dioxide emissions in the world. Therefore, the main question raised is why cement manufacturers have not decided to implement a greener solution. 

Some cement production firms state that they are indeed working on how to reduce the CO₂ emissions, however, their clients are not willing to invest in new technologies due to the increased expenses. "There is so far too little demand for sustainable materials. I would love to see more demand from customers for it. There is limited sensitivity for carbon emissions in the construction of a building," Jens Diebold, head of sustainability at LafargeHolcim, a Swiss multinational company that manufactures building materials, said. Nevertheless, it is true that the cost is a major issue as greener forms of cement cost three times more than usual mixes.

According to the European Cement Association, the manufacturing of one ton of cement produces about half a ton of carbon dioxide, which is more than a car's production on a 2000-kilometer trip. The majority of the CO₂ derives from the limestone heating procedure as the chemical reaction (CaCO₃ + heat → CaO + CO₂) produces the greenhouse gas.

An intelligent solution that is currently investigated is replacing the clinker (produced by the limestone heating process) with other substances e.g. fly-ash that can produce a geopolymer binder. "This alternative eco-friendly binder technology reduces the carbon emissions associated with normal Portland cement by 80% to 90%, and also has a much lower embodied energy. We have been working with leading companies in South East Asia, New Zealand, India, Europe and the Middle East who are extremely interested in adopting this technology," Cameron Coleman, chief executive officer of Wagners Holding Co., stated.

However, this approach probably won't thrive in European countries and in the United States. Fly-ash is produced in coal plants that are currently closing. Therefore, the utilization of fossil-fuel alternatives for heat is also being considered.