Posts Tagged ‘Carbon Dioxide’


Cleaning up Concrete!

Wednesday, December 7th, 2011

Charlie Rubin started reconditioning wooden barrels over 100 years ago. Max Rubin started reconditioning steel drums over 60 years ago. Maxi Container has been reconditioning and recycling industrial packaging since 1980. We didn’t know then that we were “green”. We thought that it made sense to reuse an expensive container over and over. Reuse wasn’t a choice made to save resources, it was an economic necessity during the Great Depression and WWII. Even as we became a disposable society, Maxi Container resisted the pressure to sell “one and done” thin steel drums. We often joke that we are in an industry that people do not know exists and, if they do, do not realize how committed to reuse and sustainability we are as a company and an industry.

Imagine my surprise when reading an article at the Smithsonian website about a new concrete that I learned:

  • Last year, the world produced 3.6 billion tons of cement—the mineral mixture that solidifies into concrete when added to water, sand and other materials. Globally, the only substance people use more of than concrete, in total volume, is water
  • The recipe for making cement calls for heating limestone, which requires fossil fuels.
  • When heated, limestone sends carbon dioxide gas wafting into the atmosphere, where it traps heat, contributing to global warming.
  • Cement production is responsible for 5 percent of the world’s human-produced carbon dioxide emissions.
  • Typically, a cement factory produces nearly a ton of carbon dioxide for every ton of cement.

In steps Nikolaos Vlasopoulos, an environmental engineer at Imperial College in London who worked summers measuring carbon dioxide levels with his uncle at a cement plant in Greece. He has developed a cement that is made with magnesium oxide and magnesium carbonates. These are made by adding carbon dioxide to his mixture. The cement, in some scenarios, is not just carbon neutral—it’s carbon negative. For every ton of Vlasopoulos’ cement produced, one-tenth of a ton of carbon dioxide could be absorbed.

There are several other companies trying to make a better, more eco-friendly, cement. Stanford Professor Brent Constantz along with venture capitalist Vinod Khosla have formed a company called Calera Corp. which has a pilot factory in Moss Landing, CA. Their process harnesses carbon dioxide emitted from a power plant and mixes it with seawater or brine to create carbonates that are used to make cement. Calera says that for every ton of cement they make, they can sequester a half of ton of carbon dioxide.

Both the Calera and Vlasopoulos cement have an interesting characteristic in common. They are both white, while normal cement is gray. This means that you can add color to it and that builders, architects and artists can not only use it to make environmentally friendly buildings, but colorful ones as well.

Some of these new approaches to cement are already in use. On Interstate 35W, just east of Minneapolis, the St. Anthony Falls Bridge carries 10 lanes of traffic on box girders borne by massive arching piers, which are supported, in turn, by footings and deep pilings. The bridge, built to replace one that collapsed in 2007, uses components made from different concrete mixes. The mix used in the wavy sculptures at both ends of the bridge is designed to stay gleaming white by scrubbing stain-causing pollutants from the air.

Just like people don’t realize how sustainable industrial packaging can be, who knew that cement could become a green technology? Have you heard of a surprising green product or technology? We would love to hear from you, please leave your response in the comments below.