- Category: Low-Carbon Biz
19 Mar 2013
- Published on Tuesday, 19 March 2013 09:05
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Mixing biofuel byproducts with concrete can create a stronger and greener building material.
This is the finding of a group of civil engineers at Kansas State University who have been studying ways to reduce the carbon dioxide emissions of concrete production.
“Even though making concrete is less energy intensive than making steel or other building materials, we use so much of it that concrete production accounts for between 3 to 8 percent of global carbon dioxide emissions,” said Kyle Riding, assistant professor of civil engineering.
To bring down concretes’ carbon footprint, the researchers are looking to replace part of the Portland cement that makes up concrete with more environmentally friendly materials. They have gotten good results using byproducts of cellulosic ethanol, biofuels made from inedible materials such as corn stover, wheat straw and rice straw.
With bioethanol production predicted to increase, the amount of byproduct left over will also increase. Cellulosic ethanol byproduct is known as high-lignin residue and its disposal could pose a problem in the future.
The most common choices for the disposal of high-lignin residue are to burn it for electricity or dispose of the ashes. The researchers added the high-lignin ash into their cement mix and found that it reacted chemically with the cement to make it stronger.
Tests of the finished concrete material found that replacing 20 percent of the cement with the high-lignin ash increased the strength of the concrete by 32 percent.
According to the researchers, the utilization of biofuel byproducts in concrete materials could have implications in both the construction and biofuel industries.
“If you use this in concrete to increase strength and quality, then you add value to this byproduct rather than just landfilling it. If you add value to this byproduct, then it is a positive factor for the industry. It can help reduce the cost of bioethanol production,” said Feraidon Ataie, a doctorial student in civil engineering.
Globally, around 7 billion cubic meters of concrete are used a year, making concrete the most-used industrial material after water. – EcoSeed Staff