Leaving Less of a "Footprint" in Fresh Cement

Have you ever looked at all of the things around you that are made from cement? From sidewalks, drainage culverts and pools pools to highways, bridges, and skyscrapers. It's literally everywhere in our life and truly a 'foundation' of today's society. We take it for granted, right?Well, we take the air we breath and our atmosphere for granted also. And it turns out, there is a link between cement and our environment.

The International Energy Agency estimates that 7% of all global carbon emissions comes from the manufacturing of cement, making it the second-largest industrial emitter in the world behind the iron and steel industry.  The cement-making process is a massive source of carbon dioxide to the atmosphere and is estimated to grow up to 23% by 2050 due to global population growth. There is large concern among scientists that the cement industry could single-handedly prevent achievement of the Paris Agreement global climate targets unless emissions are reduced.

Scientists are now working with the World Cement Association for the first time to discuss ways to alter the manufacturing process for making cement. The industry's huge carbon footprint partly stems from its high fuel requirements (most often satisfied by fossil fuels) to heat limestone until it chemically degrades. Yet, as much as two-thirds actually comes from the chemical production process itself which releases large amounts of carbon dioxide as a byproduct. So studying ways to reduce the carbon footprint in cement making is a positive and a big first step for an industry which has had no real changes in process for many decades.

The solution will not be easy; it will likely require changes in the materials and the manufacturing processes themselves. In fact, the solution will likely require a variety of steps. Some of the approaches currently being taken by researchers include:

  •       changes in the chemical formulas to eliminate the need to heat limestone which is               used in the making of the cement
  •       use of other recycled byproducts from other industries, such as steel slag, fly ash, clays       etc that can be mixed with alkalis to get a cement-like product
  •       recycling the CO2 emissions back into the cement
  •       accelerating the 're-absorption' of CO2 emissions by cement products

It will be a LONG, HARD road for the cement industry (pun intended). Not only will the solution be multi-faceted in process but will also require satisfaction of major safety requirements as well.

Still, the good news is that this is a start! With the huge challenge we face in reducing our carbon footprint to preserve our environment and way of life, we will be forced to look at many of the things we take for granted.....and be prepared to make changes. It's in our own...and our childrens' best interest.