We make more concrete than any other material in the world. It is used in our roads, dams, bridges, and buildings because of its versatility, strength, and durability. But little do we know this cement is not just energy intensive, but also emits enormous amounts of carbon dioxide (CO2), as well as numerous other pollutants.
Lately, scientists have developed a way to make‘green’ cement that actually removes greenhouse gases from the air so for every unit of carbon that traditional cement emits. “This green cement removes three units of carbon”, reports Voice of America News.
Conventional carbon-capture technologies can capture as much as 90 percent of the CO2 from smokestack gas, but it also uses a lot of the energy generated by the plant, which nearly doubles the cost of power for consumers, according to reports by America News.
Researchers from Niels Bohr Institute at the University of Copenhagen have found an ash/sugar cement mixture that appears to be stronger, greener and less crumbly than the traditional cement we use in households.
Normally, cement is comprised of a clay/chalk mixture that is heated at high temperatures, releasing large amounts of carbon dioxide into the atmosphere in the process. “But cement made with waste ash from sugar production is environmental friendly and stronger than ordinary cement”, said officials from the institute. The research shows that the ash helps to bind water in the cement so that it is stronger, can withstand higher pressure and crumbles less. At the same time, energy is saved and pollution from cement production is reduced”, they added.
The sugar/ash mixture was derived from countries that produce sugarcane. When sugar is extracted from the cane, it creates sugar and ash waste which some countries, like Cuba and Brazil, have already been adding to cement mixtures.
Researchers say the discovery could have global implications, given the widespread use of cement as a building material. "The cement industry is huge and if they are to adopt a new idea, they need to have proof that it works," says Heloisa Bordallo, a researcher in nanophysics at the Niels Bohr Institute.
"Traditional cement production uses a lot of energy and cement production accounting for 5 percent of global CO2 emissions. Moreover, Cement kilns emit other hazardous substances, including chromium, arsenic and mercury—a bioaccumulative toxin that can permanently damage the kidneys and nervous system, especially in children.
If you replace 20 percent of the content with ash, you are saving both CO2 emissions and raw materials, as you use 20 percent less by utilizing a waste product like ash.
So next time you are building your house, know what’s going in there!
